Method and apparatus for producing a metal oxide material

TECHNICAL FIELD

The present invention primarily relates to a method according to the preamble of claim 1 and a metal oxide material production apparatus according to the preamble of claim 9.

In particular, the invention relates to metal oxide material production apparatus configured for heating and/or firing the metal ore material so as to harden the metal ore material into the metal oxide material (e.g. iron oxide material) ready for transport to costumers and/or for charging into a direct reduction facility for production of reduced metal material (reduced iron material).

The present invention relates to the art of beneficiating metal ore materials, particularly iron ore materials, and is concerned with improvements in pelletizing metal ore material, particularly iron ore concentrates.

The present invention further relates to a data program programmed for controlling the production of the metal ore material into the metal oxide material.

The present invention primarily concerns the mining industry.

The present invention also may concern manufacturers and suppliers of apparatuses for producing metal oxide material, for direct reduction facilities and steel making industries etc.

BACKGROUND OF THE INVENTION

Typically, a metal ore material, such as iron ore material, to be beneficiated, comprises both magnetite material and hematite material and may further comprise other iron ore raw materials, such as limonite, siderite etc. The metal ore material, such as the iron ore material to be beneficiated often is formed into so-called green pellets, balls, bodies etc. with a diameter of about e.g. 5 to 25 mm.

Typically, the metal ore material is moist and may comprise a binder material, such as bentonite, organic binders, etc. to provide strength to the metal ore material before fed into the metal oxide material production apparatus. Of course, the induration temperature and the holding time required for induration of the metal ore material in the induration zone depend on the mineralogy of the metal ore material as well as binder type and amount.

To remove the moist from the metal ore material and for strengthening the metal ore material, before feeding it into the induration zone of the metal oxide material production apparatus, the metal ore material is pre-heated in the pre-heating zone of the metal oxide material production apparatus.

For drying the moist metal ore material and for strengthening the metal ore material, before feeding it into the pre-heating zone, the moist metal ore material is dried in a drying zone comprising a down-draft process gas zone and/or an up-draft process gas zone.

The strength of the dried metal ore material is sufficient to build a bed of metal ore material on a metal ore material feeding device employed by the pre-heating zone of the metal oxide material production apparatus.

Traditionally, according to prior art, some of the magnetite of the metal ore material subjected to pre-heating in the pre-heating zone will oxidize to hematite, wherein an exothermal chemical reaction generates heat and causes the hematite to recrystallize before being fed into the induration zone.

Traditionally, the metal ore material is transferred by means of a moving chain grate on which the metal ore material is first dried and then pre-heated to e.g. a temperature of about 1000 °C in the pre-heating zone and thereafter the pre-heated metal ore material is moved into the induration zone, such as a kiln or oven, where the pre-heated metal ore material may be fired by means of oil burners to a temperature of about 1300 - 1450 °C. Traditionally, the induration zone is configured to oxidize and sinter the pre-heated metal ore material. However, oxidation of the pre-heated metal ore material is not completely achieved in the induration zone and some oxidation may occur in a subsequent cooling step. A cooler is configured to cool down the metal ore oxide material, wherein a cooling atmosphere containing oxygen will cause extended oxidization of the metal ore subject to cooling.

Traditionally, the oil burners configured to fire the pre-heated metal ore material for providing said induration. Current metal oxide material production apparatuses consume a substantial quantity of fossil fuels for the production of the metal oxide material, which in turn contributes to global warming. The oil burners are configured to burn oil fuels or different gaseous fuels or mixtures thereof.

Traditionally, a large amount of thermal energy is wasted by known metal oxide material production apparatuses.

Current metal oxide material production apparatuses are bulky and costly in operation and assembly due to applied complex oil burner systems, burn fuel supply lines, burn fuel pumps, burn fuel distribution valves, etc.

SUMMARY OF THE INVENTION

There is an object to provide an energy-saving and cost-effective production of metal oxide material by means of a metal oxide material production apparatus, which belongs to the next generation of metal oxide material production apparatuses.

There is an object to reduce the emission of carbon dioxide (CO2) and nitrogen oxides (NOx) for decreasing the effect of global warming.

There is an object to provide efficient production of metal oxide material at the same time as efficient control in oxidizing the metal ore material into a metal oxide material.

There is an object to optimize the thermal profile of the pre-heated metal ore material for reaching homogenous and high quality of the produced metal oxide material.

There is an object to provide a stable metal oxide material that is prevented from oxidizing in a cooling step and during transport to a reduction facility.

There is an object to optimize the production of metal oxide material with high quality, at the same time as reduced energy consumption is achieved.

There is an object to increase the production rate of metal oxide material and/or make it possibly to design a more compact metal oxide material production apparatus.

These or at least one of said objects has been achieved by a method of oxidizing a metal ore material into a metal oxide material by means of a metal oxide material production apparatus, which comprises a pre-heating zone configured to pre-heat the metal ore material into a pre-heated metal ore material; a process gas introduction device coupled to the pre-heating zone and configured for introduction of a process gas into the pre-heating zone; an induration zone configured for induration of the pre-heated metal ore material into said metal oxide material; an oxidation agent introduction device coupled to the induration zone and configured to introduce an oxygen rich oxidation agent into the induration zone; and a control circuitry coupled to the process gas introduction device and the oxidation agent introduction device for controlling the induration of the metal ore material into the metal oxide material.

In such way, the pre-heating of the metal ore material in the oxygen deficient pre-heating atmosphere involves that no oxidation of the metal ore material is actual. By saving the reactivity for oxidizing the metal ore material, it is now possibly to achieve an efficient oxidizing in the induration zone, wherein efficient and complete oxidizing takes place in the induration zone.

Alternatively, the pre-heating zone comprises a pre-heating zone heating device.

Alternatively, the step of pre-heating the metal ore material is achieved by means of the preheating zone heating device configured to introduce thermal energy into the pre-heating zone for pre-heating the metal ore material fed into the pre-heating zone.

Alternatively, the metal ore material is moved by means of a metal ore material feeding device, such as a steel belt conveyor member, a moving roster unit, or by other means, from a drying zone into the pre-heating zone and optionally further through the induration zone.

Alternatively, the induration zone comprises a grate member and a rotating kiln configured to sinter the pre-heated and oxidized metal ore material.

Alternatively, from the induration zone, the metal oxide material is fed into a cooler device, such as an annular cooler configured to recover thermal energy from the indurated metal oxide material, which thermal energy is fed back to the pre-heating zone and/or drying zone.

Alternatively, the metal oxide material production apparatus further comprises a metal ore material bed applicator configured to apply a bed of the metal ore material onto a metal ore material feeding device configured for feeding the metal ore material through the preheating zone and/or the induration zone.

Alternatively, the thickness/height of the bed corresponds with measure larger than about 10-50 times the dimension of the average dimension of a metal ore material body of the metal ore material fed through the pre-heating zone and/or the induration zone by means of the metal ore material feeding device.

Alternatively, the thickness/height of the bed corresponds with a measure, which is about 50-100 times the dimension of the average dimension of a metal ore material body (e.g. a pellet) of the metal ore material fed through the pre-heating zone and/or the induration zone by means of the metal ore material feeding device.

Alternatively, the thickness/height of the bed corresponds with a measure, which is about 10-50 times the dimension of the average dimension of a metal ore material body (e.g. a pellet) of the metal ore material fed through the pre-heating zone and/or the induration zone by means of the metal ore material feeding device.

By means of the oxygen rich oxidation agent introduced into the induration zone, the thickness/height of a preferred bed can be set to be thicker than prior art. The oxygen rich oxidation agent is, due to its high oxygen content, able to diffuse into the bed of metal ore material through the entire thickness, wherein the thickness of the preferred bed of metal ore material is thicker than prior art beds.

Alternatively, the oxygen rich oxidation agent is introduced to the bed of pre-heated metal ore material in the induration zone from above, from below, sideways, or a combination thereof.

By means of the oxygen rich oxidation agent introduced into the induration zone it is possible to achieve efficient oxidization of the pre-heated metal ore material throughout the entire thickness of the bed of the pre-heated metal ore material subject to oxidization.

By making use of the oxygen rich oxidation agent, the flow rate of the oxygen rich oxidation agent introduced into the induration zone can be kept relatively low versus prior art metal oxide material production apparatuses that use high flow rate of low content oxygen oxidization gas introduced into the induration zone for achieving oxidization of the preheated metal ore material.

In such way is achieved that less energy is needed for operating e.g. a process gas fan unit or blower unit coupled to the induration zone in relation to prior art.

In such way is achieved that oxidation of the pre-heated metal ore material is made throughout the entire bed thickness of pre-heated metal ore material at the same time as energy is saved.

By making use of the oxygen rich oxidation agent, the induration zone may be designed to be shorter than prior art induration zones, due to the efficient oxidization of the pre-heated metal ore material by means of the oxygen rich oxidation agent.

In such way the metal oxide material production apparatus can be designed less bulky than prior art metal oxide material production apparatuses.

Alternatively, the process gas may be fed upward as well as downward through a bed of the metal ore material subject to pre-heating in the pre-heating zone for providing efficient heat transfer to the metal ore material subject to pre-heating in the pre-heating zone.

Alternatively, the thickness of the bed is about 25-75 cm, preferably about 35-65 cm.

Alternatively, the thickness of the bed is about 30-70 cm, preferably about 40-60 cm.

Alternatively, the thickness of the bed is about 40-80 cm, preferably about 50-70 cm.

By moving a thicker bed of pre-heated metal ore material through the induration zone, it is possible to oxidize a larger quantity of pre-heated metal ore material, which in turn permits cost-effective and high-rate production of metal oxide material.

The strength of the dried metal ore material is sufficient to build the bed of metal ore material on a metal ore material feeding device employed by the pre-heating zone of the metal oxide material production apparatus.

In such way, it is possible to achieve a well-defined temperature gradient formed in the bed of metal ore material subject to pre-heating and induration. In such way, the temperature gradient can be controlled to be as even as possible throughout the pre-heating zone and the induration zone for providing an even quality of the metal oxide material.

In such way is achieved inferior quality of the pre-heated metal ore material across the thickness of the bed of metal ore material.

Alternatively, the process gas is an oxygen deficient process gas.

Alternatively, the process gas comprises air.

Alternatively, the process gas constitutes an oxygen deficient process gas comprises about CI- 25 vol. % oxygen, preferably about 5-21 vol. % oxygen.

Alternatively, the process gas comprises less than about 22 vol. % oxygen.

Alternatively, the process gas comprises about 1-19 vol. % oxygen, preferably about 5-15 vol. % oxygen.

Alternatively, the process gas comprises about 2-15 vol. %, preferably about 4-11 vol. % oxygen.

Alternatively, the content of oxygen defined by vol. % of the process gas is a relative term independently of the temperature of the introduced process gas into the pre-heating zone.

Alternatively, the flow of oxygen rich oxidation agent may be relatively low, still as the metal ore material is capable to react with oxygen to produce the metal oxide material due to the high content of oxygen in the oxygen rich oxidation agent.

Alternatively, the process gas is fed into the pre-heating zone to such extent that the oxygen of the oxygen deficient process gas prevents oxidation of the metal ore material in the preheating zone.

Alternatively, the process gas is fed into the pre-heating zone to such extent that the oxygen of the oxygen deficient process gas substantially prevents oxidation of the metal ore material in the pre-heating zone

In such way is achieved that the energy content of the metal ore material is saved until to be released in the induration zone, in which induration zone the oxygen of the oxygen rich oxidation agent enables oxidation of the pre-heated metal ore material within a well-defined induration zone and enables optimal development of thermal energy of the metal oxide material to be discharged from the induration zone.

Alternatively, the process gas is fed into the pre-heating zone to such extent that the oxygen of the oxygen deficient process gas prevents oxidation of the metal ore material in the preheating zone, preventing development of thermal energy of the metal ore material to such extent that metal ore particles of the metal ore material not adhere to each other.

In such way is achieved that the pre-heated metal ore material (i.e. the metal ore particles of the metal ore pellets) remains with optimal porosity until being introduced into the induration zone.

In such way is achieved that the oxygen of the oxygen rich oxidation agent enables to reach the pre-heated metal ore material for enabling oxidation of the pre-heated metal ore material within a well-defined induration zone and enables optimal development of thermal energy of the metal oxide material to be discharged from the induration zone.

Alternatively, the control circuitry is adapted to control the flow of the oxygen rich oxidation agent into the induration zone for controlling the oxidation of the pre-heated metal ore material.

In such way, by means of providing the oxidation within the well-defined induration zone, the control circuitry enables to control and monitor the oxidation of the pre-heated metal ore for optimal development of thermal energy of the metal oxide material to be discharged from the induration zone.

In such way is achieved that the oxidation developing the thermal energy in the induration zone provides a temperature of the oxidized metal ore enabling sintering of the pre-heated metal ore material and/or the metal oxide material in the induration zone without the need of adding heat energy to the induration zone, or to just some extent add heat energy to the induration zone.

Alternatively, the oxygen rich oxidation agent is pre-heated before being introduced into the induration zone to such extent that the pre-heated metal ore material is prevented to be cooled in the induration zone. Alternatively, the electrolysis unit is configured to provide at least a portion of the preheated oxygen rich oxidation agent to be fed into the induration zone.

Alternatively, the control circuitry is adapted to control the flow of pre-heated oxygen rich oxidation agent into the induration zone in a low flow mode for avoiding the generation of a large amount of exhaust gas discharged from the induration zone.

In such way, cost-effective filtering of the exhaust gas is provided due to the low flow mode.

The low flow mode of the oxygen rich oxidation agent introduced into the induration zone is achieved by means of the high content of oxygen of the oxygen rich oxidation agent.

Alternatively, the production of the metal ore material comprises the steps of; mining metal ore containing rock fragments; grinding the metal ore containing rock fragments into crushed fragments; separating metal ore particles from the crushed fragments in a fluid; forming metal ore material bodies of said metal ore particles; drying the bodies in a drying zone for providing the metal ore material ready to be fed into the pre-heating zone.

Alternatively, the method comprises further the steps of; feeding the metal ore material into the pre-heating zone; introducing the process gas into the pre-heating zone and heating the induration zone atmosphere for pre-heating the metal ore material; feeding the pre-heated metal ore material into the induration zone; introducing the oxygen rich oxidation agent into the induration zone for oxidizing the pre-heated metal ore material into said metal oxide material; and discharging the metal oxide material from the induration zone.

Alternatively, the process gas is heated for providing the pre-heating of the metal ore material.

Alternatively, the induration zone is configured to oxidize and sinter the pre-heated metal ore material.

Alternatively, the oxygen rich oxidation agent is fed into the induration zone for indurating and/or concentrating the pre-heated metal ore material.

Alternatively, the oxidizing and sintering of the pre-heated metal ore material being provided simultaneously and/or separately in the induration zone. Alternatively, the sintering of the metal ore material is partly provided in the pre-heating zone.

Alternatively, the control circuitry is configured to control the oxidation rate and/or the induration temperature for efficiently oxidizing the metal ore material into the metal oxide material.

Alternatively, the control circuitry is configured to control the sintering rate and/or the induration temperature and/or pre-heating temperature for efficiently sintering the metal ore material into the metal oxide material.

Alternatively, the process gas constitutes an oxygen deficient process gas comprises about 0- 21 vol. % oxygen, preferably about 5-20 vol. % oxygen and/or the oxygen rich oxidation agent comprises about 25-100 vol. % oxygen, preferably about 40-80 vol. % oxygen.

Alternatively, the process gas constitutes an oxygen deficient process gas comprises about 0- 20 vol. % oxygen, preferably about 8-15 vol. % oxygen and/or the oxygen rich oxidation agent comprises about 40-80 vol. % oxygen, preferably about 50-70 vol. % oxygen.

Alternatively, the oxygen rich oxidation agent comprises about 30-100 vol. % oxygen, preferably about 50-80 vol. % oxygen.

Alternatively, the oxygen rich oxidation agent comprises about 80-100 vol. % oxygen, preferably about 85-95 vol. % oxygen.

Alternatively, the oxygen rich oxidation agent comprises about 60-80 vol. % oxygen, preferably about 65-75 vol. % oxygen.

Alternatively, the oxygen rich oxidation agent comprises about 40-60 vol. % oxygen, preferably about 55-65 vol. % oxygen.

Alternatively, the oxygen rich oxidation agent comprises pure oxygen.

Alternatively, the content of oxygen defined by vol. % of the oxygen rich oxidation agent is a relative term independently of the temperature of the introduced oxygen rich oxidation agent into the induration zone. In such way there is provided a strong and hard metal oxide material (e.g. iron ore agglomerates or pellets), which is resistant to crushing during subsequent handling and transport prior the production of sponge iron and steel.

In such way is achieved an efficient control the oxidation and/or sintering of the pre-heated metal ore material comprising magnetite material, for meeting a complex physic-chemical process, which involves oxidation and/or sintering of the chemical induration process.

In such way is achieved an efficient control of heat transfer from the pre-heated metal ore material, during the oxidation and/or sintering, to the induration zone atmosphere.

Alternatively, the control circuitry is configured to control the flow rate of the oxygen rich oxidation agent into the induration zone and/or control the oxygen rich oxidation agent gas pressure in the induration zone and/or control the temperature of the induration zone atmosphere by operating an induration zone atmosphere gas burner device and/or induration zone atmosphere electrical heater device.

In such way there is achieved highly exothermic chemical reaction resulting in significant temperature gradients inside the metal ore material body or pellet, providing that sintering of the metal ore material is performed rapidly and effectively.

By the use of the oxygen rich oxidation agent there is provided a metal oxide material production apparatus comprising the control circuitry that is configured to control the thermal profile of the metal ore material during the induration taking into account the oxidation, sintering and the heat transfer parameters.

In such way there is provided a metal oxide material production apparatus providing specific chemical reactions for oxidation of the magnetite material for producing excess thermal energy, which may be recovered and brought back to the pre-heating zone and in turn promotes an energy saving and efficient method.

In such way, the time for oxidation in the induration zone is minimized due to the high oxygen content and rapid oxidation is achieved by the large amount of oxygen molecules available around each metal ore material body of the pre-heated metal ore material. Hence, the higher concentration of oxygen of the oxygen rich oxidation agent, the faster is the initial oxidation of the magnetite material, which promotes a cost-effective production of the metal oxide material.

Alternatively, the thermal energy for oxidisation and/or the sintering of the pre-heated metal ore material in the induration zone is caused by the oxidation of magnetite material per se, which oxidation provides thermal energy to the induration zone.

In such way is achieved that the introduced oxygen rich oxidation agent does not have to be heated for heating the induration zone atmosphere.

In such way is achieved that the induration zone atmosphere does not have to be heated by means of e.g. a gas burner or other type of burner.

In such way is achieved that metal oxide material can be produced in an energy efficient way.

In such way is achieved a carbon-free production of metal oxide material that is resistant to further oxidation as it is assured by the used introduced oxygen rich oxidation agent that complete oxidation of the pre-heated metal ore material is achieved.

In such way is achieved that efficient and rapid oxidization is achieved by means of the oxygen deficient process gas in the pre-heating zone atmosphere for avoiding premature oxidization of the magnetite material in the pre-heating zone, whereas rapid and complete oxidization is provided in the induration zone comprising the high oxygen content atmosphere.

Alternatively, the induration zone atmosphere of the induration zone is heated by an induration zone atmosphere gas burner device and/or induration zone atmosphere electrical heater device.

Alternatively, the metal ore material and the pre-heated metal ore material comprise iron ore material and the metal oxide material comprises iron oxide material.

Alternatively, the pre-heated metal ore material comprises pre-heated iron ore pellets.

Alternatively, the metal oxide material comprises iron oxide pellets. Alternatively, the metal oxide material comprises a metal oxide material body that constitutes a metal oxide pellet, a metal oxide ball or a metal oxide agglomeration piece, etc.

Alternatively, the control circuitry is adapted to control the exothermic chemical reaction of the oxidisation of the pre-heated metal ore material, for achieving significant temperature gradients inside the pre-heated metal ore material thereby achieving energy efficient sintering of the metal ore material.

Alternatively, the control circuitry is adapted to control the temperature of the induration zone atmosphere by regulating the first gas burner device and/or the flow of oxygen rich oxidation agent introduced into the induration zone.

In such way is achieved that the achieved metal oxide material is produced with predetermined quality properties, achieved by the completely oxidized metal oxide material resistant to further oxidation during transport of the metal oxide material. The determined quality properties may be the pre-determined density of the metal oxide material to be produced, the dimension of the produced metal oxide material bodies, the porosity of the metal oxide material, etc.

Alternatively, the control circuitry is configured to control the temperature of the preheated metal ore material and/or the oxygen content of the oxygen rich oxidation agent and/or the holding time for holding the pre-heated metal ore material in the induration zone and/or the oxygen rich oxidation agent flow rate in the induration zone and/or the oxygen rich oxidation agent pressure in the induration zone and/or the oxidation rate of the preheated metal ore material.

In such way, the metal oxide material production apparatus can be optimized to produce the metal oxide material that exhibits homogenous and high quality.

Alternatively, the control circuitry is adapted to control the temperature of the induration zone atmosphere and/or of the pre-heating zone atmosphere and/or of a drying zone atmosphere of the drying zone.

Alternatively, the method comprises feeding the process gas upward as well as downward through a bed of metal ore material in the pre-heating zone for providing efficient heat transfer to the metal ore material. Alternatively, the control circuitry is adapted to control the sintering of the pre-heated metal ore material in the pre-heating zone and/or the induration zone by controlling the temperature of the process gas for pre-heating the metal ore material and/or controlling the temperature of the induration zone atmosphere by means of a first hydrogen burner and/or controlling the temperature of the pre-heating zone atmosphere by means of a second hydrogen burner and/or by controlling the temperature of the oxygen rich oxidation agent for indurating the pre-heated metal ore material.

It is thus achieved that the formation of the pre-heated metal ore material exhibits crystallographic properties.

In order to predict the optimum thermal profile to achieve homogenous high-quality metal oxide material bodies, the control circuitry is adapted to control the metal oxide material production apparatus from specific parameters.

The specific parameter may be:

-the temperature of the process gas (controlling the temperature of the oxygen deficient process gas by means of an electrical heater and/or a heat exchanger and/or a gas burner etc. adapted to heat the process gas and coupled to the control circuitry), and/or

-the temperature of the pre-heating zone atmosphere, and/or

-the temperature of the pre-heated metal ore material ready to be fed into the induration zone, and/or

-the holding time for retaining the metal ore material in the pre-heating zone during a predetermined specific time taking into account the temperature of the induration zone atmosphere, by means of controlling the speed rate of a driving arrangement configured for driving the metal ore material feeding device, which is coupled to the control circuitry), and/or

-the pressure and/or flow of the process gas in the pre-heating zone by means of a process gas flow regulating device coupled to the control circuitry, and/or -the temperature of the induration zone atmosphere (controlling the temperature of the induration zone atmosphere by means of a gas burner, e.g. a hydrogen burner, adapted to heat the process gas and coupled to the control circuitry), and/or

-the temperature of the oxygen rich oxidation agent (controlling the temperature of the oxygen rich oxidation agent by means of an electrical heater and/or a heat exchanger and/or a gas burner etc. adapted to heat the oxygen rich oxidation agent and coupled to the control circuitry), and/or

-the temperature of the metal oxide material ready to be discharged from the induration zone by taking into account the oxidation rate of the magnetite material, and/or

-the holding time for retaining the pre-heated metal ore material in the induration zone during a pre-determined specific time taking into account the temperature of the induration zone atmosphere, and/or

-the pressure and/or flow of the oxygen rich oxidation agent in the induration zone by means of a flow regulating device, and/or

-the oxidation rate of the magnetite material by controlling the temperature of the induration zone atmosphere and/or temperature of the oxygen rich oxidation agent and/or the temperature of the oxygen rich oxidation agent and/or the holding time for retaining the pre-heated metal ore material in the induration zone, and/or the pressure and/or flow of the oxygen rich oxidation agent in the induration zone by means of an oxygen rich oxidation agent flow-regulating device.

It is thus possible to control the oxidation of the magnetite material into the hematite material in an efficient way for producing high-quality metal oxide material.

Alternatively, the oxygen rich oxidation agent and/or the pre-heated metal ore material being heated by means of a first gas burner device, for example by means of a first hydrogen gas burner device, for providing thermal energy to the oxygen rich oxidation agent and/or to the pre-heated metal ore material.

Alternatively, the oxygen rich oxidation agent achieves thermal energy by means of transferring recovered thermal energy from the discharged metal oxide material. Alternatively, the oxygen rich oxidation agent achieves thermal energy by means of a first electrical heating device.

Alternatively, the method comprises a step of transferring excess heat from the induration zone to the pre-heating zone.

Alternatively, the first gas burner device of the induration zone is configured to further heat the pre-heated metal ore material in the induration zone, which first gas burner device is configured to produce a controlled flame by mixing a fuel gas with an oxidizer allowing combustion.

Alternatively, the first gas burner device is configured to provide further thermal energy to the metal ore material subject to oxidation.

Alternatively, the first gas burner device comprises a first plurality of hydrogen gas burners.

Alternatively, the first plurality of hydrogen gas burners are configured to fire and/or heat the pre-heated metal ore material in the induration zone, wherein the oxidation of the magnetite material into the hematite material provides additional thermal energy to the induration zone atmosphere and/or to the pre-heated metal oxide material to be discharged from the induration zone.

Alternatively, the metal ore material comprising the magnetite material and the step of oxidizing pre-heated metal ore material involves oxidation of the magnetite material into a hematite material, wherein an exothermal chemical reaction generates heat (thermal energy).

Alternatively, the exothermal chemical reaction generates heat and causes the hematite material to recrystallize and causing grain growth.

In such way is achieved that thermal energy is provided by means of the oxidation of the magnetite material into the hematite material, wherein the produced metal oxide material is managed to hold a specific thermal energy by means of the control circuitry.

The metal oxide material holding thermal energy may be charged (e.g. directly) into a direct reduction facility subsequently discharged from the induration zone. Alternatively, the thermal energy may be recovered and re-used by the metal oxide material production apparatus.

Alternatively, the step of introducing the process gas comprises introduction of a heated oxygen deficient process gas into the pre-heating zone for reducing or eliminating oxidisation of the metal ore material in the pre-heating zone before being fed into the induration zone.

In such way is achieved that the metal ore material, subject to pre-heating and/or the preheated metal ore material, is prevented from oxidizing before introduced into the induration zone.

In such way is achieved that the step of introducing the oxygen rich oxidation agent into the induration zone for oxidizing the pre-heated metal ore material results in optimal and energy efficient oxidation of the magnetite material into the hematite material, wherein an exothermal chemical reaction is fully developed in the induration zone by means of the oxygen rich oxidation agent introduced into the induration zone.

In such way, the fully developed exothermal chemical reaction in the induration zone involves that the metal oxide material discharged from the induration zone is fully oxidized, whereby the metal oxide material will not oxidize again when subjected to any atmosphere containing oxygen, such as a cooling zone atmosphere in a cooling zone of a cooler device configured to cool down the metal oxide material discharged from the induration zone.

In such way a high content of thermal energy, provided by the oxidization of the magnetite material into the hematite material, is limited to the induration zone, which in turn promotes efficient oxidization and/or sintering of the metal ore material subject to induration.

In such way is achieved that the energy content of the magnetite material is saved until the pre-heated metal ore material is exposed to the oxygen rich oxidation agent in the induration zone.

Alternatively, the process gas achieves thermal energy by means of a second gas burner device, for example by means of a second hydrogen gas burner device configured to heat the process gas and/or the pre-heating zone atmosphere. Alternatively, the process gas achieves thermal energy by means of transferring recovered thermal energy from the discharged metal oxide material.

Alternatively, the process gas achieves thermal energy by means of a second electrical heating device.

Alternatively, the second gas burner device comprises a second plurality of hydrogen gas burners.

Alternatively, the second plurality of hydrogen gas burners are configured to heat the iron ore material in the pre-heating zone.

Alternatively, the oxygen rich oxidation agent comprises oxygen that is produced by an electrolysis unit.

Alternatively, the first and/or second gas burner device being configured to burn hydrogen produced by the electrolysis unit.

Alternatively, the electrolysis unit is configured to decompose water into hydrogen and into an oxygen.

Alternatively, the hydrogen is fed from the electrolysis unit to the first hydrogen burner via a hydrogen pipe arrangement coupled between the electrolysis unit and the first and/or second gas burner device.

Alternatively, the oxygen is fed from the electrolysis unit to the induration zone via an oxygen pipe arrangement coupled between the electrolysis unit and the induration zone.

Alternatively, the oxygen holds thermal energy caused by an electrolysis process achieved by the electrolysis unit, which thermal energy is added to the oxygen rich oxidation agent and/or the process gas.

Alternatively, the control circuitry is coupled to a first gas flow regulator of the first gas burner device for controlling the thermal energy of the oxygen rich oxidation agent.

Alternatively, the control circuitry is coupled to a second gas flow regulator of the second gas burner device for controlling the thermal energy of the process gas. Alternatively, the control circuitry is coupled to an oxygen rich oxidation agent flowregulating device for controlling the flow of the oxygen rich oxidation agent into the induration zone.

Alternatively, the control circuitry is adapted to control the oxidation of the pre-heated metal ore material by means of the oxygen rich oxidation agent flow-regulating device for maintaining high oxygen pressure during the oxidation and/or sintering of the pre-heated metal ore material.

Alternatively, the control circuitry is coupled to a process gas flow-regulating device for controlling the flow of the process gas into the pre-heating zone.

Alternatively, the method further comprises the steps of; cooling down the discharged metal oxide material by means of a cooler device; and transferring recovered thermal energy from the discharged metal oxide material to the pre-heating zone.

Alternatively, the step of induration of the pre-heated metal ore material is achieved by means of introduction of the oxygen rich oxidation agent by means of the oxidation agent introduction device.

Alternatively, the temperature of the oxygen rich oxidation agent is controlled by the control circuitry coupled to the first electrical heating device configured to heat the oxygen rich oxidation agent.

Alternatively, the control circuitry is coupled to a second waste thermal energy fluid regulating device configured for controlling the flow of the waste thermal energy fluid comprising recovered thermal energy to be used in the pre-heating zone and/or induration zone, which recovered thermal energy is recovered from the metal oxide material cooled down by the cooler device configured to cool down the metal oxide material discharged from the induration zone.

Alternatively, the step of pre-heating the metal ore material is achieved by means of the preheating zone heating device configured to introduce thermal energy into the pre-heating zone, wherein the pre-heating zone heating device is coupled to the second waste fluidregulating device for increasing the thermal energy introduced by the pre-heating zone heating device. Alternatively, the step of transferring recovered thermal energy from the discharged metal oxide material into the pre-heating zone and/or induration zone comprises heating of said oxygen deficient process gas fed into the pre-heating zone and/or comprises heating of said oxygen rich oxidisation agent fed into the induration zone.

Alternatively, the heating of the oxygen rich oxidisation agent and/or the process gas being achieved by the recovered thermal energy is provided means of a heat exchange device.

Alternatively, the method further comprises the step of controlling the pre-heating of the metal ore material for causing the pre-heated metal ore material to reach a temperature of about 700-900 °C, preferably about 800 °C, by means of the control circuitry.

In such way is achieved that the pre-heated metal ore material holding thermal energy caused by the pre-heating zone will be subjected to an efficient oxidizing process in the induration zone.

Alternatively, the method further comprises the step of controlling the oxidation rate for oxidizing the pre-heated metal ore material into said metal oxide material by means of the control circuitry.

Alternatively, the control circuitry is adapted to control the oxidation rate by adjusting the residence time or holding time that the pre-heated metal ore material resides in the induration zone.

Alternatively, the control circuitry is adapted to control the oxidation process for oxidizing the pre-heated metal ore material into said metal oxide material to reach a temperature of about 1100-1500 °C, preferably 1200-1400 °C.

Alternatively, the induration zone is divided into at least a first induration zone and a second induration zone.

Alternatively, the first induration zone is configured to receive a first flow of oxygen rich oxidation agent and the second induration zone is configured to receive a second flow of oxygen rich oxidation agent.

Alternatively, the control circuitry is adapted to control the oxidation of the pre-heated metal ore material by means of a first oxygen rich oxidation agent flow-regulating device coupled to the control circuitry for providing a first oxygen pressure during the oxidation and/or sintering of the pre-heated metal ore material in the first induration zone.

Alternatively, the control circuitry is adapted to control the oxidation of the pre-heated metal ore material by means of a second oxygen rich oxidation agent flow-regulating device coupled to the control circuitry for providing a second oxygen pressure during the oxidation and/or sintering of the pre-heated metal ore material in the second induration zone.

Alternatively, the first oxygen pressure is higher than the second oxygen pressure.

Alternatively, the induration zone comprises a first volume configured to receive a first flow of oxygen rich oxidation agent and comprises a second volume configured to receive a second flow of oxygen rich oxidation agent, wherein the second volume having less oxygen than the first volume.

Alternatively, the control circuitry is adapted to control the oxidation of the metal ore material into the metal oxide material, wherein the control circuitry is configured to control that the metal oxide material discharged from the induration zone is completely oxidized during the oxidization and/or sintering of the pre-heated metal ore material.

This promotes the design of an energy saving process and a simplified process system, wherein no subsequently oxidisation of the magnetite is present in the cooler device.

Alternatively, the control circuitry is configured to control the cooling of the discharged metal oxide material.

Alternatively, the metal ore material is in the form of so-called green pellets.

Alternatively, before being loaded onto the metal ore material feeding device that is moved through the pre-heating zone and the induration zone, the metal ore material has already been processed in several steps for providing the so-called green pellets to be introduced into the pre-heating zone.

Alternatively, the so-called green pellets consist of a relatively large amount of water, magnetite and different additives chosen to fit the demand of a customer.

These or at least one of said objects has been achieved by a metal oxide material production apparatus comprising; a pre-heating zone configured to pre-heat a metal ore material into a pre-heated metal ore material; a process gas introduction device coupled to the pre-heating zone and configured for introduction of a process gas into the pre-heating zone; an induration zone configured for induration of the pre-heated metal ore material into said metal oxide material; an oxidation agent introduction device coupled to the induration zone and configured to introduce an oxygen rich oxidation agent into the induration zone configured for oxidizing the pre-heated metal ore material into said metal oxide material; a control circuitry configured to control the induration of the metal ore material into said metal oxide material.

Alternatively, the metal oxide material production apparatus comprises a metal ore material feeding device configured for feeding the metal ore material into the pre-heating zone.

Alternatively, the metal ore material feeding device is configured for feeding the pre-heated metal ore material into the induration zone.

Alternatively, the metal ore material feeding device is configured for feeding the metal oxide material from the induration zone to a cooler device.

Alternatively, the oxidation agent introduction device of the induration zone is coupled to the control circuitry.

Alternatively, the second electrical heating device is configured to heat the process gas to be introduced into the pre-heating zone and/or to heat the metal ore material fed into the preheating zone.

Alternatively, the metal ore material feeding device forms a common feeding apparatus extending through the metal oxide material production apparatus.

Alternatively, the oxidation agent introduction device is coupled to the induration zone configured for oxidizing and/or sintering the pre-heated metal ore material into said metal oxide material, whereas a magnetite material of the pre-heated metal ore material oxidizes to a hematite material in the induration zone, causing an exothermal chemical reaction that generates thermal energy to the pre-heated metal ore material subject to oxidisation and/or sintering.

Alternatively, the magnetite material of the pre-heated metal ore material oxidizes to the hematite material in the induration zone providing that the hematite material will recrystallize efficiently for providing high quality of the metal oxide material to be discharged from the induration zone.

Alternatively, the exothermal chemical reaction provides thermal energy transfer from the pre-heated metal ore material subject to oxidisation and/or sintering to an induration zone atmosphere of the induration zone.

Alternatively, the induration of the magnetite material causing the exothermal chemical reaction involves oxidisation, sintering and the heat transfer, which may be performed simultaneously and which may influence each other in the induration zone.

Alternatively, the pre-heating zone comprises at least one process gas introduction arrangement.

Alternatively, the process gas introduction arrangement comprises a second burner device and/or a second electrical heating device configured to heat the process gas.

Alternatively, the process gas introduction arrangement comprises a thermal heat recovering and feeding device.

Alternatively, the metal oxide material production apparatus comprises a cooler device configured to cool down the metal oxide material discharged from the induration zone.

Alternatively, the thermal heat recovering and feeding device is configured to recover thermal energy from the discharged metal oxide material and to feed the recovered thermal energy to the pre-heating zone and/or the induration zone.

Alternatively, the thermal heat recovering and feeding device is coupled to the cooler device.

Alternatively, the thermal heat recovering and feeding device comprises a heat exchange unit and a fluid line arrangement coupled to the cooler device.

Alternatively, the cooler device comprises a cooling zone for providing a cooling zone atmosphere, which is provided for cooling down the metal oxide material holding thermal energy discharged from the induration zone.

Alternatively, the cooler device is configured to recover thermal energy from the metal oxide material (holding thermal energy) discharged from the induration zone into the cooler device, wherein the heat exchange unit is configured to exchange the recovered thermal energy into thermal energy of the waste thermal energy fluid transferred from the cooler device to the pre-heating zone and/or induration zone.

Alternatively, the thermal heat recovering and feeding device comprises a first heattransferring device configured to transfer recovered thermal energy from the metal oxide material to the induration zone.

Alternatively, the thermal heat recovering and feeding device comprises a second heattransferring device configured to transfer recovered thermal energy from the metal oxide material to the pre-heating zone.

Alternatively, the metal ore material comprises lime, shale, bentonite or other materials.

Alternatively, the drying zone is configured to dry the moist metal ore material at a temperature of about 50-250 °C, preferably 100-200 °C.

Alternatively, the pre-heating zone is configured to pre-heat the metal ore material at a temperature of about 300-750 °C, preferably 400-650 °C.

Alternatively, the induration zone is configured to oxidize the pre-heated metal ore material at a temperature of about 750 -1350 °C.

Alternatively, the induration zone is configured to sinter the pre-heated metal ore material at a temperature of about 750 -1350 °C.

In such way is achieved spheroidizing of the pre-heated metal ore material in the induration zone involving converting its structure into spheroidal form achieving solid diffusion.

Alternatively, the control circuitry is adapted to control the spheroidizing of the pre-heated metal ore material in the induration zone by adjusting the residence time and temperature of the metal ore material subject to induration.

Alternatively, the influence of time, temperature, lime content, ore type, shale content and particle-size distribution are parameters that is controlled by the control circuitry.

In such way is achieved that the residence time for the pre-heated metal ore material can be short in the induration zone, as the oxygen rich oxidation agent will result in rapid magnetite oxidation and the exothermic reaction provides that the metal oxide material will exhibit high temperature after induration.

Such shortened residence time also promotes the design of a less bulky and less complex metal oxide material production apparatus.

Alternatively, the control circuitry is configured to control the degree of oxidization and/or sintering of the pre-heated metal ore material by adjusting the temperature and the oxygen content of the oxygen rich oxidation agent.

Alternatively, the control circuitry is configured to control the oxidization of the magnetite to occur rapidly in the first induration zone having higher temperature than the second induration zone, whereas the degree of oxidization increases by less extent in the second induration zone.

Alternatively, a gas burner increases the temperature in the second induration zone.

Alternatively, the metal oxide material production apparatus comprises a straight grate furnace or a grate kiln furnace.

Alternatively, a separation barrier is arranged between the pre-heating zone and the induration zone and separates the pre-heating zone atmosphere from the induration zone atmosphere for preventing that oxygen deficient process gas would mix with the oxygen rich oxidation agent.

Alternatively, the separation barrier may be achieved by controlling the pressurization of the pre-heating zone atmosphere and the induration zone atmosphere or may be a wall having an opening through which the feeding arrangement, such as a feeder belt, extends.

These or at least one of said objects has been achieved by a metal oxide material production configuration comprising an electrolysis unit configured to decompose water into oxygen and hydrogen; an electric energy production apparatus configured for production of re- generatively generated electric energy fed to the electrolysis unit.

Alternatively, the metal oxide material production apparatus comprises an oxygen rich oxidation agent fluid line coupled between the induration zone and the electrolysis unit and configured to transfer the oxygen rich oxidation agent from the electrolysis unit to the induration zone.

Alternatively, the oxygen rich oxidation agent fluid line comprises the process gas fan unit or the blower unit for providing the required flow rate of the oxygen rich oxidation agent introduced into the induration zone.

In such way there is an effective way to make use of oxygen produced by an electrolysis unit, which also produces hydrogen for various applications and usage, e.g. in a direct reduction facility configured for reduction of the metal oxide material holding thermal energy.

Alternatively, the control circuitry is adapted to control the flow of the process gas in the pre-heating zone by means of a process gas flow regulating device coupled to the control circuitry up to a sufficient temperature for efficient pre-heating of the metal ore material but not to such extent that the metal oxide material oxidizes.

Alternatively, the control circuitry is adapted to control an oxygen rich oxidation agent flowregulating device of the oxidation agent introduction device for providing an efficient oxidization of the pre-heated metal ore material.

Alternatively, the oxygen rich oxidation agent flow-regulating device of the oxidation agent introduction device comprises the process gas fan unit or the blower unit, being electrically coupled to the control circuitry for controlling the required flow rate of the oxygen rich oxidation agent introduced into the induration zone.

Alternatively, the control circuitry is adapted to control the metal ore material feeding device configured for feeding the metal ore material through the pre-heating zone and/or the induration zone for achieving efficient temperature of the metal ore material for oxidization and up to a sufficient temperature for efficient pre-heating of the metal ore material but not to such extent that the metal oxide material oxidizes.

Alternatively, the control circuitry is electrically coupled to a pre-heating zone temperature sensor member and is electrically coupled to the process gas flow-regulating device for controlling the flow of the process gas into the pre-heating zone.

Alternatively, the control circuitry is electrically coupled to the second gas burner for adjusting the temperature of the pre-heating zone atmosphere. Alternatively, the pre-heating zone temperature sensor member is configured to detect the temperature of the pre-heating zone atmosphere by means of the control circuitry.

Alternatively, the control circuitry is adapted to, by means of controlling the process gas flow-regulating device and/or the second gas burner device, control the temperature of the pre-heating zone atmosphere toward at least one specific parameter, such as a specific temperature of the pre-heating zone atmosphere, which specific temperature causes the metal ore material to be efficiently pre-heated but not sintered before being fed into the induration zone.

Alternatively, the control circuitry is electrically coupled to an induration zone temperature sensor member and is electrically coupled to an oxygen rich oxidation agent flow-regulating device for controlling the flow of the oxygen rich oxidation agent into the induration zone.

Alternatively, the control circuitry is electrically coupled to the first gas burner for adjusting the temperature of the induration zone atmosphere.

Alternatively, the induration zone temperature sensor member is configured to detect the temperature of the induration zone atmosphere by means of the control circuitry.

Alternatively, the control circuitry is adapted to, by means of controlling the oxygen rich oxidation agent flow-regulating device and/or the first gas burner device, control the temperature of the induration zone atmosphere toward at least one specific parameter, such as a specific temperature of the induration zone atmosphere, which specific temperature causes the metal ore material to oxidize through the entire thickness of the bed of metal ore material and to be sintered before being discharged from the induration zone.

These or at least one of said objects has been achieved by method of production of iron ore oxide material by means of an iron ore oxide material production apparatus, which comprises a pre-heating zone configured to pre-heat an iron ore material into a pre-heated iron ore material and which comprises an induration zone configured for induration (oxidizing and/or sintering) of the pre-heated iron ore material into said iron ore oxide material. Alternatively, the iron ore oxide material production apparatus comprises a process gas introduction device, configured to introduce a process gas into the pre-heating zone for preheating the iron ore oxide material.

Alternatively, the iron ore oxide material production apparatus comprises an oxidation agent introduction device configured to introduce an oxygen rich oxidation agent into the induration zone for oxidizing the pre-heated iron ore oxide material into the iron ore oxide material.

Alternatively, the iron ore oxide material production apparatus comprises a control circuitry coupled to the process gas introduction device and to the oxidation agent introduction device for controlling the pre-heating of the iron ore oxide material and for controlling the oxidizing the pre-heated iron ore oxide material.

Alternatively, the iron ore oxide material production apparatus comprises a feeding device comprising a feeding arrangement, which is configured for feeding the iron ore material into the pre-heating zone and further through the induration zone.

Alternatively, the feeding device is configured for feeding the iron ore material produced by a sorting-concentration-slurry rolling apparatus into the pre-heating zone.

Alternatively, the sorting-concentration-slurry rolling apparatus comprises a grinding and purification station for removing silicon, sodium, phosphorus, apatite etc. from a raw iron ore raw material for providing the iron ore material.

Alternatively, the sorting-concentration-slurry rolling apparatus comprises a slurry rolling drum for producing "green pellets" comprising iron ore material to be fed into the preheating zone.

Alternatively, the iron ore material formed the "green pellets" exhibit a diameter of about e.g. 5 to 25 mm.

Alternatively, the iron ore material comprises magnetite material (iron oxide compound) and may further comprise other iron ore raw materials, such as limonite, siderite etc.

Alternatively, the iron ore material comprises an iron oxide compound, such as magnetite material. Alternatively, the iron ore material comprises an iron oxide compound, such as hematite material.

Alternatively, it is advantageous to pre-heat the iron ore material comprising the iron oxide compound in the pre-heating zone comprising a pre-heating zone atmosphere fed with a process gas, which is an oxygen deficient process gas which comprises about 0-21 vol. % oxygen.

Alternatively, the process gas constitutes an oxygen deficient process gas which comprises about 0-5 vol. % oxygen, preferably about 1-4 vol. % oxygen.

Alternatively, the oxygen deficient process gas comprises less than 5 vol. % oxygen.

Alternatively, the oxygen deficient process gas comprises about 1-10 vol. % oxygen, preferably about 3-7 vol. % oxygen.

Alternatively, the oxygen deficient process gas comprises about 1-6 vol. %, preferably about 2-5 vol. % oxygen.

Alternatively, the oxygen rich oxidation agent comprises about 22-50 vol. % oxygen, preferably about 25-40 vol. % oxygen.

Alternatively, the oxygen rich oxidation agent comprises about 30-70 vol. % oxygen, preferably about 40-60 vol. % oxygen.

Alternatively, the oxygen rich oxidation agent comprises about 40-80 vol. % oxygen, preferably about 50-70 vol. % oxygen.

Alternatively, the oxygen rich oxidation agent comprises about 50-90 vol. % oxygen, preferably about 60-80 vol. % oxygen.

Alternatively, the iron ore oxide material production apparatus comprises a cooler device configured to cool down the iron ore oxide material (i.e the oxidized pre-heated iron ore material).

Alternatively, the iron ore oxide material production apparatus comprises a control circuitry adapted to control the oxidation process set up to oxidize the pre-heated iron ore material. Alternatively, the control circuitry is adapted to control the oxidization temperature and the holding time for oxidization.

Alternatively, the control circuitry is adapted to control the oxidization temperature and the holding time for oxidization of the pre-heated iron ore material into the iron ore oxide material in the induration zone.

Alternatively, the oxidization temperature required for oxidation of the pre-heated iron ore material is controlled by the control unit from actual mineralogy of the iron ore material.

Alternatively, the holding time required for oxidization of the metal ore material in the induration zone is controlled by the control unit based on actual mineralogy of the iron ore material.

Alternatively, the method further comprises the step of controlling the pre-heating of the metal ore material for causing the pre-heated metal ore material to reach a temperature of about 700-900 °C, preferably about 800 °C, by means of the control circuitry.

Alternatively, the control circuitry is adapted to control the oxidation process for oxidizing the pre-heated metal ore material into said metal oxide material to reach a temperature of about 700-1350 °C, preferably 850-1200 °C.

Alternatively, the drying zone is configured to dry the moist metal ore material at a temperature of about 100-500 °C, preferably 200-400 °C.

Alternatively, the pre-heating zone is configured to pre-heat the metal ore material at a temperature of about 650-950 °C, preferably 700-900 °C.

Alternatively, the induration zone is configured to oxidize the pre-heated metal ore material at a temperature of about 750 -1350 °C, preferably 800-1300 °C.

Alternatively, the induration zone is configured to oxidize the pre-heated metal ore material at a temperature of about 700 -1350 °C, preferably 750-1300 °C.

Alternatively, the feeding arrangement comprises a travelling grate device configured to move the iron ore material through the pre-heating zone and further through the induration zone. Alternatively, the feeding arrangement comprises a travelling grate device configured to move the iron ore material through the pre-heating zone and the feeding arrangement further comprises a rotary kiln configured to oxidizing and sintering of the pre-heated iron ore material and move the pre-heated iron ore material subject to induration from the preheating zone to the cooler device.

Alternatively, the feeding arrangement comprises a travelling grate device configured to move the iron ore material through the pre-heating zone and further through an after firing zone for oxidization of the pre-heated iron ore material and moreover the feeding arrangement comprises a rotary kiln configured to oxidizing of the pre-heated iron ore material subject to induration.

Alternatively, the induration zone constitutes the travelling grate device situated in the after firing zone and constitutes the rotary kiln.

Alternatively, the control circuitry is adapted to control the holding time required for oxidization of the metal ore material in the induration zone material by regulating the speed rate of the travelling grate device of the feeding arrangement.

Alternatively, a travelling grate speed sensor is electronically coupled to the control circuitry for sensing the speed rate of the travelling grate device.

Alternatively, a temperature sensor is electronically coupled to the control circuitry for sensing the temperature of the pre-heated iron ore material subject to induration and/or the temperature of the produced iron ore oxide material leaving the induration zone.

Alternatively, the control circuitry is adapted to regulate the temperature of the pre-heated iron ore material subject to induration and the speed rate of the travelling grate device from a pre-determined induration (oxidation) parameter value taking into account the actual speed rate (holding time) and said temperature.

Alternatively, the travelling grate device is mechanically coupled to a drive motor for driving the travelling grate device with a speed rate in view of said pre-determined induration (oxidation) parameter value.

In such way, the control circuitry is configured to control the oxidation of the pre-heated iron ore material into said iron ore oxide material by regulating the holding time and the temperature of the pre-heated iron ore material subject to oxidization in the induration zone.

The expression "metal oxide material" may be replaced by the expression "iron ore oxide material".

The expression "metal oxide material production apparatus" may be replaced by the expression "iron ore oxide material production apparatus".

The expression "metal ore material" may be replaced by the expression "iron ore material".

The expression "process gas" may be replaced by the expression "oxygen deficient process gas".

The present disclosure may not be restricted to the examples described above, but many possibilities to modifications, or combinations of the described examples thereof should be apparent to a person with ordinary skill in the art without departing from the basic idea as defined in the appended claims.

BRIEF DESCRIPTION OF THE DRAWING

Hereinafter, the invention will be described with reference to examples and accompanying schematic drawings, wherein for the sake of clarity and understanding of the invention some details of no importance may be deleted from the drawings.

Fig. 1 illustrates a metal oxide material production apparatus according to a first example;

Fig. 2 illustrates a metal oxide material production apparatus according to a second example;

Fig. 3 illustrates a metal oxide material production apparatus according to a third example;

Figs. 4a-4c illustrate a metal oxide material production apparatus according to a fourth example;

Fig. 5 illustrates a metal oxide material production apparatus according to a fifth example;

Fig. 6 illustrates a metal oxide material production apparatus according to a sixth example; Fig. 7 illustrates a metal oxide material production apparatus according to a seventh example;

Figs. 8-9 illustrate flowcharts showing exemplary methods of production of metal oxide material;

Fig. 10 illustrates a control circuitry of an exemplary metal oxide material production apparatus; and

Fig. 11a and lib illustrate further examples of iron ore oxide material production apparatuses.

DETAILED DESCRIPTION

Fig. 1 shows a metal oxide material production apparatus 3 comprising a pre-heating zone 8 configured to pre-heat a metal ore material 2 into a pre-heated metal ore material 4. The metal oxide material production apparatus 3 further comprises a process gas introduction device 6 coupled to the pre-heating zone 8 configured for introduction of a process gas 7 into the pre-heating zone 8, an induration zone 10 configured for induration of the preheated metal ore material 4 into said metal oxide material 5, and an oxidation agent introduction device 12 coupled to the induration zone 10 configured to introduce an oxygen rich oxidation agent 14 into the induration zone 10. The oxygen rich oxidation agent 14, such as pure oxygen generated by an electrolysis unit 15, is configured for oxidizing the preheated metal ore material 4 into said metal oxide material 5. The metal oxide material production apparatus 3 further comprises a control circuitry 50 configured to control the induration of the metal ore material 2 into said metal oxide material 5. The metal oxide material production apparatus 3 further comprises a feeder belt 20 configured for feeding the metal ore material 2 into the pre-heating zone 8 and further into the induration zone 10.

The control circuitry 50 is adapted to control the oxidation of the pre-heated metal ore material 4 in the induration zone 10 by means of an oxygen rich oxidation agent flow regulating device (not shown) of the oxidation agent introduction device 12. The oxidation agent introduction device 12 is coupled to the control circuitry 50 for providing a desired oxygen pressure in the induration zone 10 during the oxidation and/or sintering of the pre- heated metal ore material 4 in the induration zone 10. The control circuitry 50 is configured to control the flow rate of the oxygen rich oxidation agent 14 into the induration zone 10 via the oxidation agent introduction device 12.

The control circuitry 50 may be adapted to control at least one specific parameter of the method of induration of the metal ore material 2 into a metal oxide material 5 by means of a metal oxide material production apparatus 3.

The specific parameter may be:

-the temperature of the process gas (controlling the temperature of the oxygen deficient process gas by means of an electrical heater and/or a heat exchanger and/or a second gas burner etc. adapted to heat the process gas and coupled to the control circuitry50), and/or

-the temperature of the pre-heating zone atmosphere, and/or

-the temperature of the pre-heated metal ore material ready to be fed into the induration zone, and/or

-the holding time for retaining the metal ore material in the pre-heating zone 8 during a predetermined specific time taking into account the temperature of the induration zone atmosphere, by controlling the speed rate of a drive motor (not shown) adapted to drive the feeder belt 20, which drive motor is coupled to the control circuitry 50, and/or

-the pressure and/or flow of the process gas in the pre-heating zone 8 by means of a process gas flow regulating device (not shown) of the process gas introduction device 6 coupled to the control circuitry 50, and/or

-the temperature of the induration zone atmosphere (controlling the temperature of the induration zone atmosphere by means of a first gas burner, e.g. a hydrogen burner 60, adapted to heat the induration zone atmosphere and coupled to the control circuitry 50), and/or

-the temperature of the oxygen rich oxidation agent (controlling the temperature of the oxygen rich oxidation agent by means of an electrical heater and/or a heat exchanger and/or a gas burner etc. adapted to heat the oxygen rich oxidation agent and coupled to the control circuitry 50), and/or -the temperature of the metal oxide material ready to be discharged from the induration zone by taking into account the oxidation rate of the magnetite material, and/or

-the holding time for retaining the pre-heated metal ore material in the induration zone 10 during a pre-determined specific time taking into account the temperature of the induration zone atmosphere, and/or

-the pressure and/or flow of the oxygen rich oxidation agent in the induration zone 10 by means of an oxygen rich oxidation agent flow regulating device (not shown) of the oxidation agent introduction device 12, and/or

-the oxidation rate of the magnetite material by controlling the temperature of the induration zone atmosphere and/or temperature of the oxygen rich oxidation agent and/or the temperature of the oxygen rich oxidation agent and/or the holding time for retaining the pre-heated metal ore material in the induration zone 10, and/or the pressure and/or flow of the oxygen rich oxidation agent in the induration zone 10 by means of the oxygen rich oxidation agent flow regulating device.

It is thus possible to control the oxidation of the magnetite material into the hematite material for reaching a high quality metal oxide material.

The oxidation agent introduction device 12 may comprise a first electrical heater (not shown) configured to heat the oxygen rich oxidation agent to be introduced into the induration zone 10, wherein the first electrical heater is coupled to the control circuitry 50 for controlling the temperature of the induration zone atmosphere.

The process gas introduction device 6 of the metal oxide material production apparatus 3 is coupled to the control circuitry 50 for controlling the flow rate of the process gas 7 fed into the pre-heating zone 8. The process gas 7 may be heated by a second electrical heater (not shown) of the process gas introduction device 6 for heating the pre-heating zone atmosphere. The second electrical heater may be coupled to the control circuitry 50 for controlling the temperature of the pre-heating zone atmosphere of the pre-heating zone 8.

The process gas 7 constitutes an oxygen deficient process gas and is fed from a process gas supply 9. The electrolysis unit 15 and/or the process gas supply 9 may be coupled to the control circuitry 50 for controlling the gas production. Alternatively, it is advantageous to pre-heat the iron ore material comprising the iron oxide compound in the pre-heating zone comprising a pre-heating zone atmosphere fed with a process gas, which is an oxygen deficient.

Alternatively, the process gas constitutes an oxygen deficient process gas which comprises about 0-5 vol. % oxygen, preferably about 1-4 vol. % oxygen.

Alternatively, the oxygen deficient process gas comprises less than 5 vol. % oxygen.

Alternatively, the oxygen deficient process gas comprises about 1-10 vol. % oxygen, preferably about 3-7 vol. % oxygen.

Alternatively, the oxygen deficient process gas comprises about 1-6 vol. %, preferably about 2-5 vol. % oxygen.

The metal oxide material production apparatus 3 further comprises a metal ore material bed applicator (not shown) configured to apply the metal ore material onto the feeder belt 20 for feeding a bed of metal ore material through the pre-heating zone 8 and the induration zone 10.

The oxygen rich oxidation agent 14 may be fed upward as well as downward through the bed of the metal ore material subject to induration in the induration zone 10 for providing efficient heat transfer to the metal ore material subject to induration in the induration zone 10.

The oxygen rich oxidation agent 14, such as pure oxygen e.g. generated by an electrolysis unit 15.

Alternatively, the oxygen rich oxidation agent comprises about 22-50 vol. % oxygen, preferably about 25-40 vol. % oxygen.

Alternatively, the oxygen rich oxidation agent comprises about 30-70 vol. % oxygen, preferably about 40-60 vol. % oxygen.

Alternatively, the oxygen rich oxidation agent comprises about 40-80 vol. % oxygen, preferably about 50-70 vol. % oxygen.

Alternatively, the oxygen rich oxidation agent comprises about 50-90 vol. % oxygen, preferably about 60-80 vol. % oxygen. Alternatively, the oxygen rich oxidation agent comprises about 30-100 vol. % oxygen, preferably about 50-80 vol. % oxygen.

Alternatively, the oxygen rich oxidation agent comprises about 80-100 vol. % oxygen, preferably about 85-95 vol. % oxygen.

Alternatively, the oxygen rich oxidation agent comprises about 60-80 vol. % oxygen, preferably about 65-75 vol. % oxygen.

Alternatively, the oxygen rich oxidation agent comprises about 40-60 vol. % oxygen, preferably about 55-65 vol. % oxygen.

The process gas 7 may be fed upward as well as downward through a bed of the metal ore material subject to pre-heating in the pre-heating zone 8 for providing efficient heat transfer to the metal ore material subject to pre-heating in the pre-heating zone 8.

The introduction of the oxygen deficient process gas into the pre-heating zone 8 reduces or eliminates the risk that the pre-heated metal ore material 4 oxidizes in the pre-heating zone 8 before being fed into the induration zone 10.

The pre-heating of the metal ore material in the oxygen deficient pre-heating atmosphere involves that no oxidation of the metal ore material is actual. By saving the reactivity for oxidizing the metal ore material, it is now possibly to achieve an efficient oxidizing in the induration zone, wherein efficient and complete oxidizing takes place in the induration zone.

Alternatively, the method further comprises the step of controlling the pre-heating of the metal ore material for causing the pre-heated metal ore material to reach a temperature of about 700-900 °C, preferably about 800 °C, by means of the control circuitry.

Alternatively, the control circuitry is adapted to control the oxidation process for oxidizing the pre-heated metal ore material into said metal oxide material to reach a temperature of about 700-1350 °C, preferably 850-1200 °C.

Alternatively, the pre-heating zone is configured to pre-heat the metal ore material at a temperature of about 650-950 °C, preferably 700-900 °C.

Alternatively, the induration zone is configured to oxidize the pre-heated metal ore material at a temperature of about 750 -1350 °C, preferably 800-1300 °C. Alternatively, the induration zone is configured to oxidize the pre-heated metal ore material at a temperature of about 700 -1350 °C, preferably 750-1300 °C.

Fig. 1 further shows a metal oxide material production configuration 71 comprising an electrolysis unit 15 configured to decompose water into oxygen and hydrogen; an electric energy production apparatus 76 configured for production of re-generatively generated electric energy fed to the electrolysis unit 15. The metal oxide material production apparatus 3 comprises an oxygen rich oxidation agent fluid line 73 coupled between the induration zone 10 and the electrolysis unit 15 and configured to transfer the oxygen rich oxidation agent 14 from the electrolysis unit 15 to the induration zone 10.

In such way there is an effective way to make use of oxygen produced by an electrolysis unit, which also produces hydrogen for various applications and usage, e.g. in a direct reduction facility configured for reduction of the metal oxide material holding thermal energy.

Fig. 2 shows a metal oxide material production apparatus 3 according to a second example. An ore metal concentrate is mixed with a binder element, moisture and other suitable process elements for producing green pellets (moist metal ore material). For drying the moist metal ore material (not shown) and for providing a metal ore material 2 with increased strength before feeding it into a pre-heating zone 8 of the metal oxide material production apparatus 3, the moist metal ore material is dried in a drying zone 44 comprising a down-draft process gas zone and/or an up-draft process gas zone (not shown). The drying zone 44 is thus configured to dry the moist metal ore material for providing the metal ore material 2 to be fed into the pre-heating zone 8.

The pre-heating zone 8 is configured to pre-heat the metal ore material 2 into a pre-heated metal ore material 4 to be fed into an induration zone 10 of the metal oxide material production apparatus 3.

A process gas introduction device 6 is coupled to the pre-heating zone 8 for introduction of an oxygen deficient process gas 7. The process gas introduction device 6 is configured to heat the oxygen deficient process gas 7 by means of an electrical heating device (not shown) or by means of any suitable heating means. The introduction of the oxygen deficient process gas 7 into the pre-heating zone 8 reduces or eliminates the possibility that the pre-heated metal ore material 4 oxidizes in the pre-heating zone 8 before being fed into the induration zone 10.

Alternatively, it is advantageous to pre-heat the iron ore material comprising the iron oxide compound in the pre-heating zone comprising a pre-heating zone atmosphere fed with a process gas, which is an oxygen deficient.

Alternatively, the process gas constitutes an oxygen deficient process gas which comprises about 0-5 vol. % oxygen, preferably about 1-4 vol. % oxygen.

Alternatively, the oxygen deficient process gas comprises less than 5 vol. % oxygen.

Alternatively, the oxygen deficient process gas comprises about 1-10 vol. % oxygen, preferably about 3-7 vol. % oxygen.

Alternatively, the oxygen deficient process gas comprises about 1-6 vol. %, preferably about 2-5 vol. % oxygen.

Alternatively, the method further comprises the step of controlling the pre-heating of the metal ore material for causing the pre-heated metal ore material to reach a temperature of about 700-900 °C, preferably about 800 °C, by means of the control circuitry.

Alternatively, a control circuitry (not shown) is adapted to control the oxidation process for oxidizing the pre-heated metal ore material into said metal oxide material to reach a temperature of about 700-1350 °C, preferably 850-1200 °C.

Alternatively, the drying zone is configured to dry the moist metal ore material at a temperature of about 100-500 °C, preferably 200-400 °C.

Alternatively, the pre-heating zone is configured to pre-heat the metal ore material at a temperature of about 650-950 °C, preferably 700-900 °C.

Alternatively, the induration zone is configured to oxidize the pre-heated metal ore material at a temperature of about 750 -1350 °C, preferably 800-1300 °C.

The induration zone 10 of the metal oxide material production apparatus 3 is configured for induration of the pre-heated metal ore material 4 into a metal oxide material 5, which subsequently is fed into a cooler 18 of the metal oxide material production apparatus 3 An oxidation agent introduction device 12 is coupled to the induration zone 10 and is configured to introduce an oxygen rich oxidation agent 14 into the induration zone 10. The oxygen rich oxidation agent 14 may comprise pure oxygen or any content between about 20-100 vol. % oxygen.

Alternatively, the oxygen rich oxidation agent comprises about 22-50 vol. % oxygen, preferably about 25-40 vol. % oxygen.

Alternatively, the oxygen rich oxidation agent comprises about 30-70 vol. % oxygen, preferably about 40-60 vol. % oxygen.

Alternatively, the oxygen rich oxidation agent comprises about 40-80 vol. % oxygen, preferably about 50-70 vol. % oxygen.

Alternatively, the oxygen rich oxidation agent comprises about 50-90 vol. % oxygen, preferably about 60-80 vol. % oxygen.

Alternatively, the oxygen rich oxidation agent comprises about 30-100 vol. % oxygen, preferably about 50-80 vol. % oxygen.

Alternatively, the oxygen rich oxidation agent comprises about 80-100 vol. % oxygen, preferably about 85-95 vol. % oxygen.

Alternatively, the oxygen rich oxidation agent comprises about 60-80 vol. % oxygen, preferably about 65-75 vol. % oxygen.

Alternatively, the oxygen rich oxidation agent comprises about 40-60 vol. % oxygen, preferably about 55-65 vol. % oxygen.

A feeding device 20 comprises a feeding arrangement 21, which is configured for feeding the metal ore material 2 into the pre-heating zone 8 and further through the induration zone 10 and subsequently into the cooler 18.

A separation barrier 26 is arranged between the pre-heating zone 8 and the induration zone 10 and separates the pre-heating zone atmosphere from the induration zone atmosphere for preventing that oxygen deficient process gas 7 would mix with the oxygen rich oxidation agent 14. The separation barrier 26 may be achieved by controlling the pressurization of the pre-heating zone atmosphere and the induration zone atmosphere or may be a wall having an opening through which the feeding arrangement 21, such as a feeder belt, extends.

Alternatively, the oxygen rich oxidation agent and/or the pre-heated metal ore material being heated by means of a first gas burner device (not shown) for providing thermal energy to the oxygen rich oxidation agent and/or to the pre-heated metal ore material 4 in the induration zone atmosphere.

The cooler 18 is configured to cool down the metal oxide material 5 discharged from the induration zone 10 and comprises a thermal heat recovering and feeding device 30 configured to recover thermal energy from the metal oxide material 5 holding thermal energy achieved by the pre-heating and oxidisation process and is configured to feed the recovered thermal energy back to the pre-heating zone 8 via a waste heat energy fluid line 31.

The thermal heat recovering and feeding device 30 comprises a heat exchange unit 40 configured to transfer thermal energy from the metal oxide material 5 to a waste heat energy absorbing fluid fed through the waste heat energy fluid line 31.

The waste heat energy fluid line 31 is coupled between the heat exchange unit 40 and the pre-heating zone 8 and/or the induration zone 10 and configured to transfer thermal energy of the waste heat carrying process fluid from the heat exchange unit 40 to the pre-heating zone 8 and/or the induration zone 10 for heating the process gas 7 and/or the oxygen rich oxidisation agent 14. The heat exchange unit 40 is coupled to an atmosphere gas fluid supply 42, which is configured to feed the waste heat energy absorbing fluid through the heat exchange unit 40.

The cooler 18 comprises a cooling zone 33 exhibiting a cooling zone atmosphere from which the heat exchange unit 40 recovers the thermal energy from the metal oxide material 5 subject to cooling. The metal oxide material 5 that has been cooled down is transferred to a metal oxide material stockpile 46.

Fig. 3 shows a metal ore material 4 comprising a magnetite material moved through a preheating zone 8 and further through an induration zone 10 of a metal oxide material production apparatus 3. The atmosphere of the pre-heating zone 8 is heated for pre-heating a metal oxide material 2 comprising the magnetite material fed into the pre-heating zone 8. The introduction of the oxygen deficient process gas 7 into the pre-heating zone 8 by means of a process gas introduction device 6 reduces or eliminates the possibility that the magnetite material of the pre-heated metal ore material 4 oxidizes in the pre-heating zone 8 before being fed into the induration zone 10.

Alternatively, it is advantageous to pre-heat the iron ore material comprising the iron oxide compound in the pre-heating zone comprising a pre-heating zone atmosphere fed with a process gas, which is an oxygen deficient.

Alternatively, the process gas constitutes an oxygen deficient process gas which comprises about 0-5 vol. % oxygen, preferably about 1-4 vol. % oxygen.

Alternatively, the oxygen deficient process gas comprises less than 5 vol. % oxygen.

Alternatively, the oxygen deficient process gas comprises about 1-10 vol. % oxygen, preferably about 3-7 vol. % oxygen.

Alternatively, the oxygen deficient process gas comprises about 1-6 vol. %, preferably about 2-5 vol. % oxygen.

Alternatively, the method further comprises the step of controlling the pre-heating of the metal ore material for causing the pre-heated metal ore material to reach a temperature of about 700-900 °C, preferably about 800 °C, by means of the control circuitry.

Alternatively, a control circuitry (not shown) is adapted to control the oxidation process for oxidizing the pre-heated metal ore material into said metal oxide material to reach a temperature of about 700-1350 °C, preferably 850-1200 °C.

Alternatively, the pre-heating zone is configured to pre-heat the metal ore material at a temperature of about 650-950 °C, preferably 700-900 °C.

Alternatively, the induration zone is configured to oxidize the pre-heated metal ore material at a temperature of about 750 -1350 °C, preferably 800-1300 °C.

Alternatively, the induration zone is configured to oxidize the pre-heated metal ore material at a temperature of about 700 -1350 °C, preferably 750-1300 °C.

The oxidizing of the pre-heated metal ore material 4 in the induration zone 10 involves oxidation of the magnetite material into a hematite material providing an exothermal chemical reaction that generates heat and causes the hematite to recrystallize, producing a metal oxide material 5.

An oxidation agent introduction device 12 is coupled to the induration zone 10 and is configured to introduce an oxygen rich oxidation agent 14, such as an oxygen containing process gas having about 50 vol. % oxygen, into the induration zone 10. An oxidation agent supply 15 is coupled to the oxidation agent introduction device 12.

Alternatively, the oxygen rich oxidation agent comprises about 22-50 vol. % oxygen, preferably about 25-40 vol. % oxygen.

Alternatively, the oxygen rich oxidation agent comprises about 30-70 vol. % oxygen, preferably about 40-60 vol. % oxygen.

Alternatively, the oxygen rich oxidation agent comprises about 40-80 vol. % oxygen, preferably about 50-70 vol. % oxygen.

Alternatively, the oxygen rich oxidation agent comprises about 50-90 vol. % oxygen, preferably about 60-80 vol. % oxygen.

Alternatively, the oxygen rich oxidation agent comprises about 30-100 vol. % oxygen, preferably about 50-80 vol. % oxygen.

Alternatively, the oxygen rich oxidation agent comprises about 80-100 vol. % oxygen, preferably about 85-95 vol. % oxygen.

Alternatively, the oxygen rich oxidation agent comprises about 60-80 vol. % oxygen, preferably about 65-75 vol. % oxygen.

Alternatively, the oxygen rich oxidation agent comprises about 40-60 vol. % oxygen, preferably about 55-65 vol. % oxygen.

Figs. 4a-4c show a metal material production apparatus 3, which comprises a pre-heating zone 8 configured to pre-heat a metal ore material 2 for providing a pre-heated metal ore material 4 and an induration zone 10 configured to indurate the pre-heated metal ore material 4 into a metal oxide material 5. The energy flow and temperatures shown in figs. 4a-4c illustrate the principle of the recovering of thermal energy from oxidizing a magnetite material of the metal ore material 2 into a hematite material of the metal oxide material 5. A process gas introduction device 6 is configured for introduction of an oxygen deficient process gas 7 into the pre-heating zone 8. The process gas introduction device 6 may comprise a heating arrangement H comprising a process start heater and/or a supplement heater and/or a recovered thermal energy inlet for pre-heating the metal ore material 2 in the pre-heating zone 8.

Alternatively, it is advantageous to pre-heat the iron ore material comprising the iron oxide compound in the pre-heating zone comprising a pre-heating zone atmosphere fed with a process gas, which is an oxygen deficient.

Alternatively, the process gas constitutes an oxygen deficient process gas which comprises about 0-5 vol. % oxygen, preferably about 1-4 vol. % oxygen.

Alternatively, the oxygen deficient process gas comprises less than 5 vol. % oxygen.

Alternatively, the oxygen deficient process gas comprises about 1-10 vol. % oxygen, preferably about 3-7 vol. % oxygen.

Alternatively, the oxygen deficient process gas comprises about 1-6 vol. %, preferably about 2-5 vol. % oxygen.

Alternatively, the method further comprises the step of controlling the pre-heating of the metal ore material for causing the pre-heated metal ore material to reach a temperature of about 700-900 °C, preferably about 800 °C, by means of the control circuitry.

Alternatively, the control circuitry 50 is adapted to control the oxidation process for oxidizing the pre-heated metal ore material into said metal oxide material to reach a temperature of about 700-1350 °C, preferably 850-1200 °C.

Alternatively, the pre-heating zone is configured to pre-heat the metal ore material at a temperature of about 650-950 °C, preferably 700-900 °C.

Alternatively, the induration zone is configured to oxidize the pre-heated metal ore material at a temperature of about 750 -1350 °C, preferably 800-1300 °C.

Alternatively, the induration zone is configured to oxidize the pre-heated metal ore material at a temperature of about 700 -1350 °C, preferably 750-1300 °C. The induration zone 10 is configured for induration of the pre-heated metal ore material 4 into the metal oxide material 5 by means of an oxygen rich oxidation agent 14 via an oxygen agent introduction device 12 coupled to the induration zone 10 and configured to introduce the oxygen rich oxidation agent 14 into the induration zone 10 from a oxidation agent supply 15. The oxygen rich oxidation agent 14 is introduced into the induration zone 10 for oxidizing and/or sintering the pre-heated metal ore material 4.

The oxygen rich oxidation agent 14, such as pure oxygen e.g. generated by an electrolysis unit 15.

Alternatively, the oxygen rich oxidation agent comprises about 22-50 vol. % oxygen, preferably about 25-40 vol. % oxygen.

Alternatively, the oxygen rich oxidation agent comprises about 30-70 vol. % oxygen, preferably about 40-60 vol. % oxygen.

Alternatively, the oxygen rich oxidation agent comprises about 40-80 vol. % oxygen, preferably about 50-70 vol. % oxygen.

Alternatively, the oxygen rich oxidation agent comprises about 50-90 vol. % oxygen, preferably about 60-80 vol. % oxygen.

Alternatively, the oxygen rich oxidation agent comprises about 30-100 vol. % oxygen, preferably about 50-80 vol. % oxygen.

Alternatively, the oxygen rich oxidation agent comprises about 80-100 vol. % oxygen, preferably about 85-95 vol. % oxygen.

Alternatively, the oxygen rich oxidation agent comprises about 60-80 vol. % oxygen, preferably about 65-75 vol. % oxygen.

Alternatively, the oxygen rich oxidation agent comprises about 40-60 vol. % oxygen, preferably about 55-65 vol. % oxygen.

The induration zone 10 may be part of a straight grate furnace wherein a feeder belt moves the pre-heated metal ore material 4 through the induration zone 10.

The induration zone may be part of a grate furnace for oxidizing and a kiln furnace configured to sinter the metal ore material. The magnetite material of the pre-heated metal ore material 4 oxidizes to hematite in the induration zone 10, causing an exothermal chemical reaction that generates thermal energy of the pre-heated metal ore material 4 subject to oxidisation, wherein the hematite will recrystallize, and subsequently the metal oxide material 5 is discharged from the induration zone 10 and transferred into a cooler 18.

Fig. 4a schematically shows start of the metal oxide material production apparatus 3 for production of cooled down metal oxide material 5. The metal ore material 2 (green pellets) holding a first specific heat energy (kJ/kgK) is fed into the pre-heating zone 8. The metal ore material 2 is pre-heated in the pre-heating zone 8 to a second specific heat energy (kJ/kgK) by means of an electrical heater and/or gas burner (not shown) of a heating arrangement H. adding a third specific heat energy (kJ/kgK) to the pre-heating zone 8.

The magnetite material of the pre-heated metal ore material 4 holding the second specific heat energy (kJ/kgK) is fed into the induration zone 10 and will oxidize and/or sinter in the induration zone 10, wherein a fourth specific heat energy (kJ/kgK) is added to the second specific heat energy (kJ/kgK) due to an exothermal chemical reaction of the magnetite material transferred into the hematite material. The achieved metal oxide material 5 now holding a fifth specific heat energy (kJ/kgK) due to said oxidisation and is transferred into the cooler 18.

By means of the cooler 18, a sixth specific heat energy (kJ/kgK) is recovered from the discharged metal oxide material 5 and is fed back to the pre-heating zone 8 by means of a process fluid. The cooled down metal oxide material 5 holding approximately similar heat energy as the first specific heat energy (kJ/kgK) is discharged from the cooler 18. The recovering of the heat energy is repeated during the production metal oxide material 5.

In Fig. 4b is shown that the metal oxide material 5 holding a fifth specific heat energy (kJ/kgK) is charged directly into a direct reduction facility 100. The metal oxide material 5 is fed to the direct reduction facility 100 without being cooled down, alternatively to some extent cooled down, wherein the heating arrangement H must be taken into operation for heating the pre-heating zone 8 for preheating the metal ore material 4 to be fed into the induration zone 10. In the induration zone 10, the pre-heated metal ore material oxidizes and the fourth specific heat energy (kJ/kgK) is added to the pre-heated metal ore material 4 by means of the exothermal chemical reaction of the magnetite material transferred into the hematite material. The achieved metal oxide material 5 holds the fifth specific heat energy (kJ/kgK) and is charged into the direct reduction facility 100 substantially without any step of cooling down the metal oxide material 5 discharged from the induration zone 10.

In Fig. 4c is shown a metal oxide material production apparatus 3 configured to direct the production of metal oxide material 5 toward the production of cooled down metal oxide material by means of a cooler 18 and/or toward charging the produced metal oxide material 5 holding the fifth specific heat energy (kJ/kgK) into a direct reduction facility 100. In case a selected quantity of the metal oxide material 5, holding the fifth specific heat energy (kJ/kgK), is to be charged into the direct reduction facility 100, the heat energy recovered by means of the cooler 18 must be added with heat energy from the heating arrangement H.

In case production of cooled-down metal oxide material is selected, the sixth specific heat energy (kJ/kgK) is recovered from the discharged metal oxide material 5 and is fed back to the pre-heating zone 8.

Alternatively, in case production of cooled-down metal oxide material is selected, the sixth specific heat energy (kJ/kgK) is recovered from the discharged metal oxide material 5 and is fed back for heating the process gas introduced in the pre-heating zone 8.

Alternatively, it is advantageous to pre-heat the iron ore material comprising the iron oxide compound in the pre-heating zone comprising a pre-heating zone atmosphere fed with a process gas, which is an oxygen deficient.

Alternatively, the process gas constitutes an oxygen deficient process gas which comprises about 0-5 vol. % oxygen, preferably about 1-4 vol. % oxygen.

Alternatively, the oxygen deficient process gas comprises less than 5 vol. % oxygen.

Alternatively, the oxygen deficient process gas comprises about 1-10 vol. % oxygen, preferably about 3-7 vol. % oxygen.

Alternatively, the oxygen deficient process gas comprises about 1-6 vol. %, preferably about 2-5 vol. % oxygen. The oxygen rich oxidation agent 14, such as pure oxygen e.g. generated by an electrolysis unit 15.

Alternatively, the oxygen rich oxidation agent comprises about 22-50 vol. % oxygen, preferably about 25-40 vol. % oxygen.

Alternatively, the oxygen rich oxidation agent comprises about 30-70 vol. % oxygen, preferably about 40-60 vol. % oxygen.

Alternatively, the oxygen rich oxidation agent comprises about 40-80 vol. % oxygen, preferably about 50-70 vol. % oxygen.

Alternatively, the oxygen rich oxidation agent comprises about 50-90 vol. % oxygen, preferably about 60-80 vol. % oxygen.

Alternatively, the oxygen rich oxidation agent comprises about 30-100 vol. % oxygen, preferably about 50-80 vol. % oxygen.

Alternatively, the oxygen rich oxidation agent comprises about 80-100 vol. % oxygen, preferably about 85-95 vol. % oxygen.

Alternatively, the oxygen rich oxidation agent comprises about 60-80 vol. % oxygen, preferably about 65-75 vol. % oxygen.

Alternatively, the oxygen rich oxidation agent comprises about 40-60 vol. % oxygen, preferably about 55-65 vol. % oxygen.

Fig. 5 illustrates a metal oxide material production apparatus 3 according to a fifth example.

The strength of the dried metal ore material is sufficient to build a bed B of metal ore material on a metal ore material feeder 20' employed by the pre-heating zone 8 and the induration zone 10 of the metal oxide material production apparatus 3.

The metal oxide material production apparatus 3 comprises a metal ore material bed applicator, such as a hopper arrangement configured for loading green pellets on the metal ore material feeder 20'. The metal ore material bed applicator (not shown) is configured to apply the bed B of the metal ore material onto the metal ore material feeder 20'. The thickness/height of the bed B corresponds with measure larger than about 10-50 times the dimension of the average dimension of a metal ore material body (pellet) of the metal ore material fed through the pre-heating zone 8 and/or the induration zone 10 by means of the metal ore material feeding device 20.

Alternatively, the thickness of the bed B may be approximately 300-800 mm, preferably 350- 750 mm.

By means of an oxygen rich oxidation agent 14 introduced into the induration zone 10, the thickness/height of the bed B can be set to be thicker than prior art beds. The oxygen rich oxidation agent 14 is, due to its high oxygen content, able to diffuse into the bed B of metal ore material through the entire thickness of the bed B.

By moving the thick bed B of metal ore material through the metal oxide material production apparatus 3 comprising the induration zone 10, it is possible to oxidize a larger quantity of pre-heated metal ore material 4, which in turn permits cost-effective and high- rate production of metal oxide material.

In such way it is possible to achieve a well-defined temperature gradient formed in the bed of metal ore material subject to pre-heating and induration, wherein the temperature gradient can be controlled to be as even as possible throughout the pre-heating zone and the induration zone for providing an even quality of the metal oxide material 5.

The metal oxide material production apparatus 3 comprises a control circuitry (not shown), which is coupled to a process gas introduction device 6 and optionally to an oxidation agent introduction device 12 for controlling the pre-heating and/or oxidisation and/or sintering of the metal ore material 2 into the metal oxide material 5.

Alternatively, the control circuitry is adapted to control the oxidation process for oxidizing the pre-heated metal ore material 4 into said metal oxide material 5 to reach a temperature of 1100-1500 °C, preferably 1200-1400 °C.

The induration zone 10 comprises a first induration zone 10' and a second induration zone 10”. The first induration zone 10' is configured to receive a first flow 14' of oxygen rich oxidation agent and the second induration zone 10” is configured to receive a second flow 14” of oxygen rich oxidation agent. The control circuitry is adapted to control the oxidation of the pre-heated metal ore material by means of a first oxygen rich oxidation agent flow regulating device (not shown) coupled to the control circuitry for providing a first oxygen pressure during the oxidation and/or sintering of the pre-heated metal ore material in the first induration zone 10'. The control circuitry is adapted to control the oxidation of the preheated metal ore material by means of a second oxygen rich oxidation agent flow regulating device (not shown) coupled to the control circuitry for providing a second oxygen pressure during the oxidation and/or sintering of the pre-heated metal ore material in the second induration zone. The first oxygen pressure may be set higher than the second oxygen pressure for providing efficient oxidation and sintering. The second oxygen pressure may be set higher than the first oxygen pressure or may be similar.

Alternatively, the method further comprises the step of controlling the pre-heating of the metal ore material for causing the pre-heated metal ore material to reach a temperature of about 700-900 °C, preferably about 800 °C, by means of the control circuitry.

Alternatively, the control circuitry is adapted to control the oxidation process for oxidizing the pre-heated metal ore material into said metal oxide material to reach a temperature of about 700-1350 °C, preferably 850-1200 °C.

Alternatively, the pre-heating zone is configured to pre-heat the metal ore material at a temperature of about 650-950 °C, preferably 700-900 °C.

Alternatively, the induration zone is configured to oxidize the pre-heated metal ore material at a temperature of about 750 -1350 °C, preferably 800-1300 °C.

Alternatively, the induration zone is configured to oxidize the pre-heated metal ore material at a temperature of about 700 -1350 °C, preferably 750-1300 °C.

Fig. 6 illustrates a metal oxide material production apparatus 3 according to a sixth example.

The strength of the dried metal ore material is sufficient to build a bed B of metal ore material on a roster support 83 employed by the induration zone 10 of the metal oxide material production apparatus 3.

Alternatively, the metal ore material is moved by means of a metal ore material feeding device, such as a steel belt conveyor member, a moving roster carriage, or by other means, from a drying zone into the pre-heating zone and optionally further through the induration zone.

The pre-heated metal ore material has been introduced into the induration zone 10 and oxygen rich oxidation agent 14 is introduced into the induration zone 10 from above, whereas an upper surface layer of the bed B starts to heavily oxidize and the oxidizing of magnetite develops thermal energy from the upper surface layer and further downward. As the metal ore material of the upper surface layer has oxidized to great extent, the deeper layers of the bed B start to heavily oxidize. Finally, a bottom surface layer of the bed B oxidises and the entire bed B of metal oxide material is ready to be discharged from the induration zone 10. This position PO is shown in Fig. 5. By means of an oxygen rich oxidation agent 14 introduced into the induration zone 10, the thickness/height of the bed B can be set to be thicker than prior art beds. The oxygen rich oxidation agent 14 is, due to its high oxygen content, able to diffuse into the bed B of metal ore material through the entire thickness of the bed B. A fan arrangement 86 is arranged to a bottom portion of the induration zone 10 for operating the flow of oxygen rich agent 14 through the bed B of metal oxide material.

The oxygen rich oxidation agent 14, such as pure oxygen e.g. generated by an electrolysis unit 15.

Alternatively, the oxygen rich oxidation agent comprises about 22-50 vol. % oxygen, preferably about 25-40 vol. % oxygen.

Alternatively, the oxygen rich oxidation agent comprises about 30-70 vol. % oxygen, preferably about 40-60 vol. % oxygen.

Alternatively, the oxygen rich oxidation agent comprises about 40-80 vol. % oxygen, preferably about 50-70 vol. % oxygen.

Alternatively, the oxygen rich oxidation agent comprises about 50-90 vol. % oxygen, preferably about 60-80 vol. % oxygen.

Alternatively, the oxygen rich oxidation agent comprises about 30-100 vol. % oxygen, preferably about 50-80 vol. % oxygen. Alternatively, the oxygen rich oxidation agent comprises about 80-100 vol. % oxygen, preferably about 85-95 vol. % oxygen.

Alternatively, the oxygen rich oxidation agent comprises about 60-80 vol. % oxygen, preferably about 65-75 vol. % oxygen.

Alternatively, the oxygen rich oxidation agent comprises about 40-60 vol. % oxygen, preferably about 55-65 vol. % oxygen.

Alternatively, the method further comprises the step of controlling the pre-heating of the metal ore material for causing the pre-heated metal ore material to reach a temperature of about 700-900 °C, preferably about 800 °C, by means of the control circuitry.

Alternatively, the control circuitry is adapted to control the oxidation process for oxidizing the pre-heated metal ore material into said metal oxide material to reach a temperature of about 700-1350 °C, preferably 850-1200 °C.

Alternatively, the drying zone is configured to dry the moist metal ore material at a temperature of about 100-500 °C, preferably 200-400 °C.

Alternatively, the pre-heating zone is configured to pre-heat the metal ore material at a temperature of about 650-950 °C, preferably 700-900 °C.

Alternatively, the induration zone is configured to oxidize the pre-heated metal ore material at a temperature of about 750 -1350 °C, preferably 800-1300 °C.

Alternatively, the induration zone is configured to oxidize the pre-heated metal ore material at a temperature of about 700 -1350 °C, preferably 750-1300 °C.

Fig. 7 shows a metal oxide material production apparatus 3 according to a seventh example. The metal oxide material production apparatus 3 comprises a cooler 18 configured to cool down a hot metal oxide material 5 discharged from an induration zone 10 of the metal oxide material production apparatus 3 and fed into the cooler 18. A heat exchange unit 40 of the cooler 18 is configured to recover thermal energy from the metal oxide material 5 discharged from the induration zone 10. The cooler 18 is configured to recover the thermal energy and transfer it to a waste heat carrying process fluid 84 being fed via the cooler 18 to a pre-heating zone 8 of the metal oxide material production apparatus 3. A waste heat energy fluid line 31 is coupled between the cooler 18 and the pre-heating zone 8 for transferring thermal energy of the waste heat carrying process fluid 84 to the pre-heating zone 8 for heating an oxygen deficient process gas 7.

Alternatively, it is advantageous to pre-heat the iron ore material comprising the iron oxide compound in the pre-heating zone comprising a pre-heating zone atmosphere fed with a process gas, which is an oxygen deficient.

Alternatively, the process gas constitutes an oxygen deficient process gas which comprises about 0-5 vol. % oxygen, preferably about 1-4 vol. % oxygen.

Alternatively, the oxygen deficient process gas comprises less than 5 vol. % oxygen.

Alternatively, the oxygen deficient process gas comprises about 1-10 vol. % oxygen, preferably about 3-7 vol. % oxygen.

Alternatively, the oxygen deficient process gas comprises about 1-6 vol. %, preferably about 2-5 vol. % oxygen.

Alternatively, the method further comprises the step of controlling the pre-heating of the metal ore material for causing the pre-heated metal ore material to reach a temperature of about 700-900 °C, preferably about 800 °C, by means of the control circuitry.

Alternatively, a control circuitry (not shown) is adapted to control the oxidation process for oxidizing the pre-heated metal ore material into said metal oxide material to reach a temperature of about 700-1350 °C, preferably 850-1200 °C.

Alternatively, the pre-heating zone is configured to pre-heat the metal ore material at a temperature of about 650-950 °C, preferably 700-900 °C.

Alternatively, the induration zone is configured to oxidize the pre-heated metal ore material at a temperature of about 750 -1350 °C, preferably 800-1300 °C.

Alternatively, the induration zone is configured to oxidize the pre-heated metal ore material at a temperature of about 700 -1350 °C, preferably 750-1300 °C.

The metal oxide material production apparatus 3 comprises a diversion mechanism 88, which is configured to change path of the metal oxide material 5 discharged from the induration zone 10. This is made by operating a conveyor belt 89 to move out from a charging entrance of direct reduction facility DR. The hot metal oxide material 5 is charged directly into the direct reduction facility DR.

Fig. 8 illustrates a flowchart showing an exemplary method of a method of production of a metal oxide material 5 by means of a metal oxide material production apparatus 3, which comprises; a pre-heating zone configured to pre-heat the metal ore material into a preheated metal ore material; a process gas introduction device coupled to the pre-heating zone and configured for introduction of a process gas into the pre-heating zone; an induration zone configured for induration of the pre-heated metal ore material into said metal oxide material; an oxidation agent introduction device coupled to the induration zone and configured to introduce an oxygen rich oxidation agent into the induration zone; and a control circuitry coupled to the process gas introduction device and to the oxidation agent introduction device for controlling the induration of the metal ore material into the metal oxide material.

The method in Fig. 8 starts at step 801. Step 802 comprises adaption of the method. Step 803 comprises stop of the method. Step 802 may comprise; feeding the metal ore material into the pre-heating zone; introducing the-pre-heating process gas for pre-heating the metal ore material; feeding the pre-heated metal ore material into the induration zone; introducing the oxygen rich oxidation agent into the induration zone for oxidizing the preheated metal ore material into said metal oxide material; and discharging the metal oxide material from the induration zone.

Fig. 9 illustrates a flowchart showing an exemplary method of production of a metal oxide material 5 by means of a metal oxide material production apparatus 3 of any example herein disclosed. The method starts at step 901. Step 902 comprises feeding the metal ore material into the pre-heating zone. Step 903 comprises introducing the-pre-heating process gas for pre-heating the metal ore material. Step 904 comprises feeding the pre-heated metal ore material into the induration zone. Step 905 comprises introducing the oxygen rich oxidation agent into the induration zone for oxidizing the pre-heated metal ore material into said metal oxide material. Step 906 comprises that the oxygen of the oxygen rich oxidation agent is produced by an electrolysis unit. Step 907 comprises controlling the pre-heating of the metal ore material for causing the pre-heated metal ore material to reach a temperature of about 700-900 °C, preferably about 800 °C, by means of the control circuitry, prior to feeding the pre-heated metal ore material into the induration zone. Step 908 comprises the step of cooling down the discharged metal oxide material by means of a cooler device. Step 909 comprises transferring recovered thermal energy from the discharged metal oxide material to the pre-heating zone. Step 910 comprises discharging the metal oxide material from the induration zone. Step 911 comprises stop of the method.

Fig. 10 illustrates a metal oxide material production apparatus 3 comprising a control circuitry 50. The control circuitry comprises a computer (not shown) and is configured to control any exemplary method herein disclosed. The control circuitry 50 may comprise a non-volatile memory NVM 1020, which is a computer memory that can retain stored information even when the control circuitry 50 or the computer is not powered. The control circuitry 50 further comprises a processing unit 1010 and a read/write memory 1050.

The NVM 1020 comprises a first memory unit 1030. A computer program (which can be of any type suitable for any operational database) is stored in the first memory unit 1030 to be used for operating the functionality of the control circuitry 50.

Furthermore, the control circuitry 50 comprises a bus controller (not shown), a serial communication port (not shown) providing a physical interface, through which information transfers separately in two directions. The control circuitry 50 also comprises any suitable type of I/O module (not shown) providing input/output signal transfer, an A/D converter (not shown) for converting varying signals-, from pre-heating zone temperature sensor members, induration zone temperature sensor members, temperature sensor devices for detecting temperatures of the metal oxide material holding thermal energy and for detecting temperatures of the process gas, oxygen deficient process gas, oxygen rich oxidation agent or any various monitoring units (not shown), -into binary code suitable to be processed by the computer of the control circuitry 50.

The control circuitry 50 further comprises an input/output unit (not shown) for adaption to time and date. The control circuitry 50 also may comprise an event counter (not shown) for counting the number of event multiples that occur during pre-heating and induration of the metal ore material for adjustment of the chemical reaction and/or the oxidization for reaching efficient sintering of the metal ore material in the induration zone. Furthermore, the control circuitry 50 includes interrupt units (not shown) for providing a multi-tasking performance and real time computing. The NVM 1020 also includes a second memory unit 1040 for external controlled operation.

A data medium adapted for storing a data program P comprises driver routines adapted for commanding the operating of the metal oxide material production apparatus 3.

The data program P is adapted for operating the control circuitry 50 in performing any exemplary method described herein. The data program P comprises routines for executing commands to the metal oxide material production apparatus 3 for achieving that the metal oxide material production apparatus 3 performs any of the exemplary methods herein disclosed. The data program P comprises a program code, which is readable on the computer, for causing the computer to control the metal oxide material production apparatus 3 to perform an exemplary method herein described.

The data program P further may be stored in a separate memory 1060 and/or in the read/write memory 1050. The data program P in this embodiment is stored in executable or compressed data format.

It is to be understood that when the processing unit 1010 is described to execute a specific function that involves that the processing unit 1010 executes a certain part of the program stored in the separate memory 1060 or a certain part of the program stored in the read/write memory 1050.

The processing unit 1010 is associated with a signal (data) port 1099 for communication via a first data bus 1015, which signal (data) port 1099 may be adapted to be electrically coupled to an electronic control circuitry of an operator station (not shown).

In such way is achieved that an operator via a display of the electronic control circuitry can control and monitor the metal oxide material production apparatus 3.

The non-volatile memory NVM 1020 is adapted for communication with the processing unit 1010 via a second data bus 1012. The separate memory 1060 is adapted for communication with the processing unit 1010 via a third data bus 1011. The read/write memory 1050 is adapted to communicate with the processing unit 1010 via a fourth data bus 1014. The signal (data) port 1099 may be connectable to data links of e.g. a network coupled to the control circuitry 50.

When data is received by the signal port 1099, the data will be stored temporary in the second memory unit 1040. After that the received data is temporary stored, the processing unit 1010 will be ready to execute the program code, in accordance with the exemplary methods.

Preferably, the signals (received by the signal (data) port 1099) comprise information about operational status of the metal oxide material production apparatus 3.

The received signals at the signal port 1099, such as a serial bus, may be used by the control circuitry 50 for controlling and monitoring the pre-heating and induration.

The signals received by the signal (data) port 1099 can be used for historic data and data regarding operation of the metal oxide material production apparatus 3.

The metal oxide material production apparatus 3 may be configured to be coupled to a data network via the signal buss configured for electrical interface explicitly providing electrical compatibility and related data transfer, which data may include information about status of the metal oxide material production apparatus 3 and its sensor devices, such as the preheating zone temperature sensor members, the induration zone temperature sensor members, the temperature sensor devices for detecting temperatures of the metal oxide material, etc. Data may also be fed manually to the computer and/or presented by the computer via a suitable communication device, such as a display (not shown) or touch screen.

Separate sequences of the method may be executed by the computer, wherein the computer runs the data program P being stored in the separate memory 1060 or the read/write memory 1050. When the computer runs the data program P, the method steps according to any example disclosed herein will be executed by means of the metal oxide material production apparatus 3.

A data program product comprising a program code stored on a data medium may be provided, which data program product is readable on the computer, for commanding the of the metal oxide material production apparatus 3 to perform any of the exemplary method steps herein disclosed, when the data program P is run on the computer.

Fig. 11a and lib illustrate further exemplary iron ore oxide material production apparatuses.

Fig. 11a illustrates an iron ore oxide material production apparatus 3, such as a straight grate, comprising a pre-heating zone 8 configured to pre-heat an iron ore material 2 into a pre-heated iron ore material 4. The iron ore material 2 may be provided by a sorting- concentration-slurry rolling apparatus 24 and being fed into the pre-heating zone 8. The metal oxide material production apparatus 3 further comprises a process gas introduction device (not shown) coupled to the pre-heating zone 8 and is configured for introduction of a process gas for pre-heating the iron ore material 2.

Alternatively, it is advantageous to pre-heat the iron ore material comprising the iron oxide compound in the pre-heating zone comprising a pre-heating zone atmosphere fed with a process gas, which is an oxygen deficient.

Alternatively, the pre-heating zone comprising a pre-heating zone atmosphere fed with a process gas, which is an oxygen deficient process gas comprises about 0-21 vol. % oxygen, preferably about 5-20 vol. % oxygen.

Alternatively, the process gas constitutes an oxygen deficient process gas which comprises about 0-5 vol. % oxygen, preferably about 1-4 vol. % oxygen.

Alternatively, the oxygen deficient process gas comprises less than 5 vol. % oxygen.

Alternatively, the oxygen deficient process gas comprises about 1-10 vol. % oxygen, preferably about 3-7 vol. % oxygen.

Alternatively, the oxygen deficient process gas comprises about 1-6 vol. %, preferably about 2-5 vol. % oxygen.

Alternatively, the method further comprises the step of controlling the pre-heating of the metal ore material for causing the pre-heated metal ore material to reach a temperature of about 700-900 °C, preferably about 800 °C, by means of the control circuitry. Alternatively, the control circuitry 50 is adapted to control the oxidation process for oxidizing the pre-heated metal ore material into said metal oxide material to reach a temperature of about 700-1350 °C, preferably 850-1200 °C.

Alternatively, the pre-heating zone is configured to pre-heat the metal ore material at a temperature of about 650-950 °C, preferably 700-900 °C.

Alternatively, the induration zone is configured to oxidize the pre-heated metal ore material at a temperature of about 750 -1350 °C, preferably 800-1300 °C.

Alternatively, the induration zone is configured to oxidize the pre-heated metal ore material at a temperature of about 700 -1350 °C, preferably 750-1300 °C.

The metal oxide material production apparatus 3 comprises an induration zone 10 configured for induration (oxidizing) of the pre-heated iron ore material 4 into an iron ore oxide material 5.

The metal oxide material production apparatus 3 comprises a feeding arrangement 21' comprising a travelling grate 28 configured to move the iron ore material 2 through the preheating zone 8 and further move the pre-heated iron ore material 4 through the induration zone 10 for oxidization of the pre-heated iron ore material 4 into the iron ore oxide material 5.

Alternatively, a separation barrier 26 is arranged between the pre-heating zone 8 and the induration zone 10 and separates the pre-heating zone atmosphere from the induration zone atmosphere for preventing that oxygen deficient process gas 7 would mix with the oxygen rich oxidation agent 14.

The pre-heating zone 8 comprises an oxidation agent introduction device 12 coupled to the induration zone 10 configured to introduce an oxygen rich oxidation agent 14 into the induration zone 10.

The oxygen rich oxidation agent 14, such as pure oxygen e.g. generated by an electrolysis unit 15.

Alternatively, the oxygen rich oxidation agent comprises about 22-50 vol. % oxygen, preferably about 25-40 vol. % oxygen. Alternatively, the oxygen rich oxidation agent comprises about 30-70 vol. % oxygen, preferably about 40-60 vol. % oxygen.

Alternatively, the oxygen rich oxidation agent comprises about 40-80 vol. % oxygen, preferably about 50-70 vol. % oxygen.

Alternatively, the oxygen rich oxidation agent comprises about 50-90 vol. % oxygen, preferably about 60-80 vol. % oxygen.

Alternatively, the oxygen rich oxidation agent comprises about 30-100 vol. % oxygen, preferably about 50-80 vol. % oxygen.

Alternatively, the oxygen rich oxidation agent comprises about 80-100 vol. % oxygen, preferably about 85-95 vol. % oxygen.

Alternatively, the oxygen rich oxidation agent comprises about 60-80 vol. % oxygen, preferably about 65-75 vol. % oxygen.

Alternatively, the oxygen rich oxidation agent comprises about 40-60 vol. % oxygen, preferably about 55-65 vol. % oxygen.

Alternatively, the induration zone atmosphere of the induration zone is heated by an induration zone atmosphere gas burner device and/or induration zone atmosphere electrical heater device (not shown).

The iron ore oxide material production apparatus 3 comprises a control circuitry 50 configured to control the oxidation of the pre-heated metal ore material into said iron ore oxide material 5 by controlling the holding time and the temperature of the iron ore material in the induration zone 10.

Alternatively, the control circuitry 50 is electrically coupled to a process gas introduction device and to the oxidation agent introduction device 12 for controlling the pre-heating of the iron ore material and for controlling the oxidizing of the pre-heated iron ore material 4 into the iron ore oxide material 5.

Alternatively, the control circuitry 50 is adapted to control the oxidization temperature and the holding time for oxidization of the pre-heated iron ore material into the iron ore oxide material in the induration zone. Alternatively, the control circuitry 50 is adapted to control the holding time required for oxidization of the pre-heated iron ore material 4 in the induration zone 10 by regulating the speed rate of the travelling grate 28 of the feeding arrangement 21' by means of regulating the speed of a drive motor 32.

Alternatively, a travelling grate speed sensor 34 is electronically coupled to the control circuitry 50 for sensing the speed rate of the travelling grate 28.

Alternatively, a temperature sensor arrangement 36 is electronically coupled to the control circuitry 50 for sensing the temperature of the pre-heated iron ore material subject to induration and/or the temperature of the iron ore oxide material 5 ready to exit the induration zone 10.

Alternatively, the control circuitry 50 is adapted to regulate the temperature of the preheated iron ore material 4 subject to induration (oxidation) and the speed rate of the travelling grate 28 from a pre-determined induration (oxidation) parameter value taking into account the actual speed rate (holding time) and said temperature.

Alternatively, the travelling grate 28 is mechanically coupled to the drive motor 32 for driving the travelling grate 28 with a speed rate taking into account said pre-determined induration (oxidation) parameter value for providing effective oxidization of the pre-heated iron ore material.

In such way, the control circuitry 50 is configured to control the oxidation of the pre-heated iron ore material 4 into said iron ore oxide material by regulating the holding time and the temperature of the pre-heated iron ore material subject to oxidization in the induration zone 10.

In such way is achieved an energy efficient and time saving method and configuration to produce the iron ore oxide material 5.

Fig. lib illustrates an iron ore oxide material production apparatus 3, such as a grate-kiln configuration. The iron ore oxide material production apparatus 3 comprises a pre-heating zone 8 configured to pre-heat an iron ore material (not shown) into a pre-heated iron ore material (not shown). The metal oxide material production apparatus 3 further comprises a process gas introduction device (not shown) coupled to the pre-heating zone 8 and is configured for introduction of a process gas for providing pre-heating of the iron ore material.

Alternatively, it is advantageous to pre-heat the iron ore material comprising the iron oxide compound in the pre-heating zone comprising a pre-heating zone atmosphere fed with a process gas, which is an oxygen deficient process gas.

Alternatively, a separation barrier 26 is arranged between the pre-heating zone 8 and the induration zone 10 and separates the pre-heating zone atmosphere from the induration zone atmosphere for preventing that oxygen deficient process gas 7 would mix with the oxygen rich oxidation agent 14.

Alternatively, the pre-heating zone comprising a pre-heating zone atmosphere fed with a process gas, which is an oxygen deficient process gas comprises about 0-21 vol. % oxygen, preferably about 5-20 vol. % oxygen.

Alternatively, the process gas constitutes an oxygen deficient process gas which comprises about 0-5 vol. % oxygen, preferably about 1-4 vol. % oxygen.

Alternatively, the oxygen deficient process gas comprises less than 5 vol. % oxygen.

Alternatively, the oxygen deficient process gas comprises about 1-10 vol. % oxygen, preferably about 3-7 vol. % oxygen.

Alternatively, the oxygen deficient process gas comprises about 1-6 vol. %, preferably about 2-5 vol. % oxygen.

The iron ore oxide material production apparatus 3 further comprises a feeding arrangement 21” comprising a travelling grate 48 configured to move the iron ore material through the pre-heating zone 8. A drive motor M is mechanically coupled to the travelling grate 48.

The motor M also drives the pre-heated iron ore material through an induration zone 10 for oxidation of the pre-heated iron ore material.

The obtained iron ore oxide material 5 is further fed to a rotary kiln 49. The rotary kiln 49 is arranged to move the iron ore oxide material subject to sintering from the induration zone 10 to a cooler device (not shown) by that the rotary kiln 49 is inclined and rotates with a specific rotation speed.

A kiln rotation speed sensor (not shown) is electronically coupled to the control circuitry 50 for sensing the rotation speed of the rotary kiln 49.

A temperature sensor arrangement 36 is electronically coupled to the control circuitry 50 for sensing the temperature of the interior of the induration zone 10.

The drive motor M is electrically coupled to a control circuitry 50 for regulating the speed of the motor M, thus regulating the holding time of the pre-heated iron ore material subject to oxidization in the induration zone.

The temperature sensor arrangement 36 is electronically coupled to the control circuitry 50 for sensing the temperature of the interior of the induration zone 10 and/or of the preheated iron ore material subject to induration (oxidation) and/or the temperature of the iron ore oxide material 5 ready to exit the induration zone 10.

Alternatively, the control circuitry 50 is adapted to regulate the rotational speed of the motor M based on a pre-determined induration (oxidation) parameter value.

Alternatively, the control circuitry 50 is adapted to regulate the temperature of the preheated iron ore material 4 subject to induration (oxidation) and the speed rate of the travelling grate 48 based on the pre-determined induration (oxidation) parameter value.

Alternatively, the pre-determined induration (oxidation) parameter value may regard the external shape of iron ore oxide material (pellet size) and/or the porosity of the iron ore oxide material 5 and/or the agglomeration grade and/or density of the produced iron ore oxide material 5 and/or the temperature of the produced iron ore oxide material 5 and/or the strength of the produced iron ore oxide material 5.

Alternatively, the control circuitry 50 is adapted to regulate the temperature of induration zone 10 and/ or the rotary kiln 49 by means of a gas burner device (not shown) and/or induration zone atmosphere electrical heater device electrically coupled to the control circuitry 50 and arranged to the induration zone 10. In such way, the control circuitry is configured to control the oxidation of the pre-heated iron ore material into said iron ore oxide material by regulating the holding time and the temperature of the pre-heated iron ore material subject to oxidization in the induration zone.

In such way is achieved an energy efficient and time saving method and configuration to produce the iron ore oxide material 5.

The oxygen rich oxidation agent 14, such as pure oxygen e.g. generated by an electrolysis unit 15.

Alternatively, the oxygen rich oxidation agent comprises about 22-50 vol. % oxygen, preferably about 25-40 vol. % oxygen.

Alternatively, the oxygen rich oxidation agent comprises about 30-70 vol. % oxygen, preferably about 40-60 vol. % oxygen.

Alternatively, the oxygen rich oxidation agent comprises about 40-80 vol. % oxygen, preferably about 50-70 vol. % oxygen.

Alternatively, the oxygen rich oxidation agent comprises about 50-90 vol. % oxygen, preferably about 60-80 vol. % oxygen.

Alternatively, the oxygen rich oxidation agent comprises about 30-100 vol. % oxygen, preferably about 50-80 vol. % oxygen.

Alternatively, the oxygen rich oxidation agent comprises about 80-100 vol. % oxygen, preferably about 85-95 vol. % oxygen.

Alternatively, the oxygen rich oxidation agent comprises about 60-80 vol. % oxygen, preferably about 65-75 vol. % oxygen.

Alternatively, the oxygen rich oxidation agent comprises about 40-60 vol. % oxygen, preferably about 55-65 vol. % oxygen.

The present disclosure may not be restricted to the examples described above, but many possibilities to modifications, or combinations of the described examples thereof should be apparent to a person with ordinary skill in the art without departing from the basic idea as defined in the appended claims.