Field

The present invention relates to iron-making and/or steel-making processes.

Background to the invention

Generally, iron-making and/or steel-making processes, for example Blast Furnace (BF) processes, Electric Arc Furnace (EAF) processes and the Basic Oxygen Steelmaking (BOS) processes, discharge large amounts of waste products. These waste products include ferrous material and carbon material, which may be collected as particles during cleaning and filtering of off gases (also known as flue gases) from these iron-making and/or steel-making processes.

Historically, these waste products were disposed in landfills. However, environmental regulations may now prohibit or penalise such disposal. Further, increased environmental regulations may now also consider prohibit or penalise accumulation of these waste products on site.

Hence, recycling of these waste products (also known as reverts or secondary materials) may be required, to meet environmental regulations. Such recycling may also beneficially recover at least some of the Fe and C included in these waste products.

These waste products are typically in the form of particles (including particulates, aggregates and/or clusters thereof) and often fine grained such that these waste products cannot be used directly in iron-making and/or steel-making processes. Hence, these waste products are typically formed into agglomerates, such as briquettes or pellets, including binders such as Portland cement, molasses or polyvinyl alcohol, PVA. The agglomerates may be subsequently included in charges, typically comprising coke, iron ore, limestone and optionally sinter, for iron-making and/or steel-making processes. By recycling these waste products in this way, at least some of the Fe and C included therein may be recovered while amounts of waste products for disposal may be decreased.

However, in addition to Fe and C, these waste products may also include undesirable elements, for example volatile metals (i.e. having relatively low melting points compared with Fe) such as Sn, Pb, Zn and/or alkali metals including Li, Na and K. Other undesirable elements may include first, second and/or third row transition metals. Other undesirable elements may also include halogens such as Cl and Br, and/or P and S. Generally, these undesirable elements may be detrimental to, and/or adversely affect efficiencies of, the steelmaking and iron-making processes and/or comprise impurities in steel or iron.

Hence, there is a need to improve recycling of waste products from steel-making and ironmaking processes.

Summary of the Invention

It is one aim of the present invention, amongst others, to provide a method of providing an agglomerate and/or a method of iron-making and/or steel-making which at least partially obviates or mitigates at least some of the disadvantages of the prior art, whether identified herein or elsewhere. For instance, it is an aim of embodiments of the invention to provide a method of providing an agglomerate for recycling waste products, thereby recovering Fe therefrom, that reduces amounts of undesirable elements therein. For instance, it is an aim of embodiments of the invention to provide a method of iron-making and/or steel-making having an increased efficiency.

A first aspect provides a method of providing an agglomerate, for example a pellet or a briquette, for use in iron-making and/or steel-making, the method comprising:

providing a mixture by binding particles, including a ferrous material and a carbon material, using a binder;

forming the mixture, thereby providing an agglomerate precursor;

curing the agglomerate precursor, thereby providing the agglomerate; and

treating the agglomerate;

wherein the binder preferably comprises an aqueous solution of polyvinyl alcohol, PVA;

wherein the agglomerate before treating has a first composition comprising:

Fe in a range from 20 wt.% to 80 wt.%, preferably in a range from 30 wt.% to 70 wt.%, more preferably in a range from 35 wt.% to 65 wt.% by weight of the agglomerate;

C in a range from 12.5 wt.% to 40 wt.%, preferably in a range from 14 wt.% to 25 wt.%, more preferably in a range from 15 wt.% to 20 wt.% by weight of the agglomerate; and

a first amount of Zn in a range from 0.10 wt.% to 10.0 wt.%, preferably in a range from 0.29 wt.% to 7.0 wt.%, more preferably in a range from 0.30 wt.% to 4.0 wt.%, most preferably in a range from 0.35 wt.% to 2.0 wt.% by weight of the agglomerate;

wherein the treating the agglomerate comprises heating the agglomerate in a presence of oxygen at a first temperature in a range from 1050 °C to 1400 °C, preferably from 1 100 °C to 1300 °C, more preferably from 1 150 °C to 1250 °C for a first duration in a range from 0.25 hours to 12 hours, preferably in a range from 0.5 hours to 3 hours, more preferably in a range from 0.75 hours to 1 .5 hours;

wherein the agglomerate after treating has a second composition comprising: Fe in a range from 30 wt.% to 90 wt.%, preferably in a range from 35 wt.% to 85 wt.%, more preferably in a range from 40 wt.% to 80 wt.% by weight of the agglomerate;

C in a range from 0.0 wt.% to 9 wt.%, preferably in a range from 0.01 wt.% to 5 wt.%, more preferably in a range from 0.1 wt.% to 1 wt.% by weight of the agglomerate; and

a second amount of Zn in a range from 0.0 wt.% to 1 .0 wt.%, preferably in a range from 0.001 wt.% to 0.5 wt.%, more preferably in a range from 0.01 wt.% to 0.1 wt.% by weight of the agglomerate;

wherein the second amount of Zn is less than the first amount of Zn.

A second aspect provides a method of iron-making and/or steel-making, comprising:

preparing a charge comprising coke, iron ore, limestone, an agglomerate, for example a pellet or a briquette, and optionally sinter or iron ore pellets; and

heating the charge to make iron or steel and thereby discharging particles, including a ferrous material and a carbon material;

wherein the method comprises providing the agglomerate according to any of claims 1 to 12.

A third aspect provides an agglomerate, for example a pellet or a briquette, for use in ironmaking and/or steel-making, having a first composition comprising:

Fe in a range from 20 wt.% to 80 wt.%, preferably in a range from 30 wt.% to 70 wt.%, more preferably in a range from 35 wt.% to 65 wt.% by weight of the agglomerate;

C in a range from 12.5 wt.% to 40 wt.%, preferably in a range from 14 wt.% to 25 wt.%, more preferably in a range from 15 wt.% to 20 wt.% by weight of the agglomerate; and

a first amount of Zn in a range from 0.10 wt.% to 10.0 wt.%, preferably in a range from 0.29 wt.% to 7.0 wt.%, more preferably in a range from 0.30 wt.% to 4 wt.%, most preferably in a range from 0.35 wt.% to 2.0 wt.% by weight of the agglomerate.

Detailed Description of the Invention

According to the present invention there is provided a method of providing an agglomerate, as set forth in the appended claims. Also provided is a method of iron-making and/or steel-making and an agglomerate for use in iron-making and/or steel-making. Other features of the invention will be apparent from the dependent claims, and the description that follows.

Method of providing an agglomerate

The first aspect provides a method of providing an agglomerate, for example a pellet or a briquette, for use in iron-making and/or steel-making, the method comprising:

providing a mixture by binding particles, including a ferrous material and a carbon material, using a binder; forming the mixture, thereby providing an agglomerate precursor;

curing the agglomerate precursor, thereby providing the agglomerate; and

treating the agglomerate;

wherein the binder preferably comprises an aqueous solution of polyvinyl alcohol, PVA;

wherein the agglomerate before treating has a first composition comprising:

Fe in a range from 20 wt.% to 80 wt.%, preferably in a range from 30 wt.% to 70 wt.%, more preferably in a range from 35 wt.% to 65 wt.% by weight of the agglomerate;

C in a range from 12.5 wt.% to 40 wt.%, preferably in a range from 14 wt.% to 25 wt.%, more preferably in a range from 15 wt.% to 20 wt.% by weight of the agglomerate; and

a first amount of Zn in a range from 0.10 wt.% to 10.0 wt.%, preferably in a range from 0.29 wt.% to 7.0 wt.%, more preferably in a range from 0.30 wt.% to 4.0 wt.%, most preferably in a range from 0.35 wt.% to 2.0 wt.% by weight of the agglomerate;

wherein the treating the agglomerate comprises heating the agglomerate in a presence of oxygen at a first temperature in a range from 1050 °C to 1400 °C, preferably from 1 100 °C to 1300 °C, more preferably from 1 150 °C to 1250 °C for a first duration in a range from 0.25 hours to 12 hours, preferably in a range from 0.5 hours to 3 hours, more preferably in a range from 0.75 hours to 1 .5 hours;

wherein the agglomerate after treating has a second composition comprising:

Fe in a range from 30 wt.% to 90 wt.%, preferably in a range from 35 wt.% to 85 wt.%, more preferably in a range from 40 wt.% to 80 wt.% by weight of the agglomerate;

C in a range from 0.0 wt.% to 9 wt.%, preferably in a range from 0.01 wt.% to 5 wt.%, more preferably in a range from 0.1 wt.% to 1 wt.% by weight of the agglomerate; and

a second amount of Zn in a range from 0.0 wt.% to 1 .0 wt.%, preferably in a range from 0.001 wt.% to 0.5 wt.%, more preferably in a range from 0.01 wt.% to 0.1 wt.% by weight of the agglomerate;

wherein the second amount of Zn is less than the first amount of Zn.

In this way, Fe may be recovered from recycled waste materials, for example, while undesirable elements, for example Zn, are removed. Particularly, at the first temperature for the first duration, the relatively high C content of the agglomerate, before treating, provides (e.g. CO) and/or is (i.e. C) a reducing agent, thereby at least partially reducing compounds of metals and/or non-metals to elemental forms, even in the presence of oxygen. Hence, Fe and Zn are at least partially reduced by and/or due to the C during the treating of the agglomerate, for example from oxides thereof to respective metals. The metallic Fe is retained in the treated agglomerate while the metallic Zn volatilises therefrom during the treating. Particularly, the relatively high C content of the agglomerate before treating provides for both at least partial reduction of compounds of the undesirable elements, at their respective amounts, and for at least partial reduction of oxides of Fe. Furthermore, the relatively high C content of the agglomerate, before treating, may provide (e.g. CO) and/or be (i.e. C) a reducing agent for compounds of other undesirable elements, which may also be at least partially removed from the agglomerate similarly during the treating. In this way, an efficiency of iron-making and/or steel-making is increased, as described below, while impurities in the iron or steel due to the undesirable elements are decreased.

It should be understood that the first composition is defined as percentages by weight (or by mass) of the agglomerate before treating and the second composition is defined as percentages by weight (or by mass) of the agglomerate after treating. Since at least some of the C is consumed (for example, reacted to form gaseous products) during the treating, since at least some compounds, for example of Fe and/or Zn, are reduced during the treating and since at least some of the reduced elements, for example Zn, are volatilised during the treating, a weight (or mass) of the agglomerate after treating is less than that before treating. Generally, compositions described herein define total amounts of a particular element, which may be present in an elemental form and/or in a compound thereof, for example an oxide thereof. For example, for Fe, an amount of Fe is a total amount of Fe present as elemental Fe (i.e. metal), Fe30 ₄ , Fe ₂ C>3 and/or FeO. Generally, where an amount of a particular oxide is instead defined, for example for CaO, this is the amount of the particular oxide present.

It should be understood that generally, metals and/or non-metals included in the agglomerate before treating are in the form of compounds thereof for example oxides, carbonates, silicates, nitrides, nitrates, sulphides, sulphates, phosphides, phosphates, borides, borates, hydroxides and/or halides thereof. That is, the metals and/or the non-metals included in the agglomerate before treating are generally not in an elemental form. C, however, may be in an elemental form, present as coke and/or coal particles, for example. It should be understood that generally, metals and/or non-metals included in the agglomerate after treating are, in contrast, in the elemental form together with residual compounds thereof for example oxides, carbonates, silicates, nitrides, nitrates, sulphides, sulphates, phosphides, phosphates, borides, borates, hydroxides and/or halides thereof.

It should be understood that the Fe in the agglomerate before treating comprises, substantially comprises (i.e. at least 50 wt.% by weight of the Fe), essentially comprises (i.e. at least 90 wt.%, preferably at least 95 wt.%, more preferably at least 97.5 wt.%, most preferably at least 99 wt.% by weight of the Fe) or consists of oxides thereof, particularly Fe30 ₄ and/or Fe ₂ 03. Elemental Fe (i.e. metal) and/or FeO may also be included. It should be understood that the Fe in the agglomerate after treating comprises, substantially comprises (i.e. at least 50 wt.% by weight of the Fe), essentially comprises (i.e. at least 90 wt.%, preferably at least 95 wt.%, more preferably at least 97.5 wt.%, most preferably at least 99 wt.% by weight of the Fe) or consists of elemental Fe (i.e. metal). Oxides thereof, for example Fe30 ₄ , Fe ₂ 03, and/or FeO may also be included. In one example, the particles before treating comprise, substantially comprise (i.e. at least 50 wt.% by weight of the particles), essentially comprise (i.e. at least 90 wt.%, preferably at least 95 wt.% by weight of the particles) or consist of waste products (also known as reverts), such as discharged from iron-making and/or steel-making ). These waste products include ferrous material and carbon material, which may be collected as particles during cleaning and filtering of off gases (also known as flue gases) from iron-making and/or steel-making processes. In one example, the particles are obtained, at least in part, from BOS and/or BF filter cakes from off gas cleaning systems. In this way, the ferrous and carbon bearing waste products from iron-making and/or steel-making processes may be re-utilised and recycled within BF and/or BOS processes, for example. Additional materials such as mill scales, slag, road sweepings and/or fine grindings from other processes may be included in the particles to control, at least in part, the ferrous content of the agglomerate precursor. In this way, materials of poor sintering quality, or that are environmentally deleterious to the traditional sinter plant route, may be included in the agglomerates, thereby providing also a potential alternative to sintering or conventional pelletising processes.

In one example, prime ores, for example milled ore concentrates, coals and/or cokes, for example coal fines and/or coke fines, are included in the particles.

In one example, the ferrous material before treating comprises iron-containing waste materials comprising at least 20 wt.% iron and/or iron ore. The ferrous material before treating may comprise other metals, non-metals and/or oxides, carbonates, silicates, nitrides, nitrates, sulphides, sulphates, phosphides, phosphates, borides, borates, hydroxides and/or halides thereof. For example, the iron may be included as Fe (i.e. metal), FeO, Fe30 ₄ and/or Fe ₂ C>3.

In one example, the carbon (also known as carbonaceous) material comprises carbon- containing waste materials, graphite, coals and/or cokes, particularly fines thereof. In one example, the particles are obtained, at least in part, from different waste products, for example works arising dust such as ladle arc dust, secondary vent dust, desulphur dust, precipitation dust and/or iron oxide dust; filter cake such as BOS filter cake, killed BOS filter cake, blast furnace filter cake (i.e. flue dust) and/or lagoon material and/or black sand (also known as BOS grit). Generally, killed BOS filter cake may be provided by killing BOS filter cake with black sand and/or works arising dust. Generally, lagoon material comprises a slurry mix of BOS filter cake and blast furnace filter cake. In one example, the method comprises obtaining and blending the particles, before and/or during providing the mixture, wherein the particles are obtained, at least in part, from different waste products, as described above, for example to provide, at least in part, the first composition. Preferably, the particles are obtained from blast furnace filter cake, killed BOS filter cake and/or lagoon material. In one example the particles comprise and/or consist of: blast furnace filter cake in a range from 30 wt.% to 60 wt.%, preferably in a range from 35 wt.% to 55 wt.%, more preferably in a range from 40 wt.% to 50 wt.%; killed BOS filter cake in a range from 22.5 wt.% to 52.5 wt.%, preferably in a range from 27.5 wt.% to 47.5 wt.%, more preferably in a range from 32.5 wt.% to 42.5 wt.%; and lagoon material in a range from 2.5 wt.% to 32.5 wt.%, preferably in a range from 7.5 wt.% to 27.5 wt.%, more preferably in a range from 12.5 wt.% to 22.5 wt.% by weight of the particles.

It should be understood that the term agglomerate refers to a briquette, a pellet and/or a granule, formed using compression for example in a roller press, a die press (including die variants such as rotating table press), an extruder and/or a pan or disc pelletiser. Generally, briquettes are relatively larger than pellets, having a dimension in a range from 25 mm to 100 mm, and formed at relatively lower compressive stresses such that a density and/or a strength may be relatively lower than that of pellets formed from the same mixture. Generally, pellets have a maximum dimension of 25 mm. Generally, briquettes are preferred, since they may be included relatively further downstream in iron-making and/or steel-making processes, thereby adding further value. For example, agglomerates having a maximum dimension of at most about 6 mm are generally only suitable for sinter production. For example, agglomerates having a maximum dimension in a range from about 6 mm to about 45 mm are suitable for inclusion in a BF charge. For example, agglomerates having a maximum dimension of at least about 45 mm may be used in a BOS process, for example as a coolant. In one example, the agglomerate is a briquette. In one example, the method comprises providing a plurality of agglomerates, for example briquettes and/or pellets, for example in an amount of from 1 ,000 tonnes to 10,000,000 tonnes per annum, preferably in an amount from 10,000 tonnes to 1 ,000,000 tonnes per annum, more preferably in an amount from 50,000 tonnes to 500,000 tonnes per annum, for example about 100,000 tonnes per annum. In this way, waste products from iron-making and/or steel-making processes may be effectively recycled, reducing and/or avoiding disposal to landfill, for example.

Binder

In one example, the binder is provided by the particles, for example at least in part included therein, such as at least in part inherently included therein, and/or at least in part provided by a particle size distribution thereof. For example, the agglomerate may be formed by pelletising, such as with a pan pelletiser, thereby also binding the particles. That is, binding and forming may be concurrent.

The binder preferably comprises the aqueous solution of polyvinyl alcohol, PVA. In one example, the binder additionally and/or alternatively comprises Portland cement and/or molasses. Other binders are known. PVA is preferred because an amount, by weight, required is relatively less than for Portland cement, for example. In this way, dilution of the Fe content of the agglomerate by the binder is decreased i.e. the Fe content of the agglomerate is maintained as high as possible.

The PVA used for this method is commercially available in powder form and covers all suitable grades that would be considered as being in the medium viscosity range and which are soluble in water. The PVA chain may be in various degrees of saturation with OH groups but typically saturation levels from 80% to fully hydrolysed are employed.

The aqueous solution of the PVA is made by heating water to near boiling temperature, adding the PVA and preparing an aqueous solution of PVA comprising PVA in a range from 5 to 20 wt.%, more preferably in a range from 8 to 12 wt.%. The width of the wt.% range depends on actual grade of PVA and viscosity. The bonding process employs the binder addition of the aqueous solution of PVA to the materials comprised in the mixture, wherein the mixture before forming contains an amount of dry PVA in a range from 0.01 wt.% to 10 wt.%, preferably in a range from 0.05 wt.% to 5 wt.%, more preferably in a range from 0.1 wt.% to 2.5 wt.%, more preferably in a range from 0.1 wt.% to 1 .2 wt.% of the total weight of the mixture, that is of the final mix of all materials constituting the mixture. Preferably, the mixture before forming contains an amount of dry PVA in a range from 0.2 to 0.8 wt.% of the total weight of the agglomerate.

In one example, the mixture before forming contains an amount of dry Portland cement in a range from 5 wt.% to 25 wt.%, preferably in a range from 7.5 wt.% to 20 wt.%, more preferably in a range from 10 wt.% to 15 wt.%, for example about 12.5 wt.% of the total weight of the mixture.

In one example, the particles are mixed prior to adding the binder and subsequently mixed with the binder to provide the mixture. In this way, a relatively more homogeneous mixture before binding may be provided.

Moisture

In one example, the method comprises controlling a moisture content of the agglomerate precursor and/or the agglomerate. In this way, the agglomerate precursor has sufficient green strength for handling prior to the curing thereof. An optimum moisture content of the agglomerate precursor may be a function, at least in part, of granularity (i.e. particle size, size distribution and/or morphology), applied pressure during forming and a method of forming, for example roll briquetting, extrusion or pellet formation. For the optimum moisture content, there may be two considerations. Firstly, related to a green strength of the agglomerate precursor and secondly, related to a final developed cured strength. In one example, a moisture content of the agglomerate precursor before the curing is in a range from 5 wt.% to 15 wt.%, preferably in a range from 8 wt.% to 12 wt.%, more preferably in a range from 10 wt.% to 11 wt.% by weight of the agglomerate precursor. In one example, a moisture content of the agglomerate after the curing and before the treating is in a range from 1 wt.% to 6 wt.%, preferably in a range from 1 wt.% to 4 wt.% by weight of the agglomerate.

In one example, controlling a moisture content comprises, before adding the binder to the mixture, adding water to the particles and/or adding CaO to the particles. In this way, final trimming (i.e. optimisation) of moisture required to form the agglomerate precursor may be provided. Hydration of burnt lime (CaO) is exothermic and hence may accelerate curing.

No reaction of particles with acid

It should be understood that the method excludes deliberate reaction of the particles with acid, for example hydrochloric acid such as in a range from about 1 wt.% to 4 wt.% such as about 2 wt.%, particularly by deliberate addition thereof to the particles before and/or during providing the mixture.

However, it should be understood that acid species may be inherent in the particles and/or may be produced upon adding the aqueous solution of the PVA to the particles. Such inherent and/or produced acid species are distinguished from deliberate addition of acid

In one example, the mixture comprises HCI in an amount of at most 1 .00 wt.%, preferably at most 0.50 wt.%, more preferably at most 0.25 wt.%, most preferably at most 0.15 wt.% by weight of the mixture. In one example, the mixture comprises HCI in an amount from 0.00 wt.% to 1 .00 wt.%, preferably in a range from 0.01 wt.% to 0.50 wt.%, more preferably in a range from 0.10 wt.% to 0.25 wt.% by weight of the mixture. That is, HCI is not deliberately added to the mixture.

In one example, the mixture comprises Cl in an amount of at most 1 .00 wt.%, preferably at most 0.75 wt.%, more preferably at most 0.50 wt.%, most preferably at most 0.25 wt.% by weight of the mixture. In one example, the mixture comprises Cl in an amount from 0.00 wt.% to 1 .00 wt.%, preferably in a range from 0.01 wt.% to 0.475 wt.%, more preferably in a range from 0.10 wt.% to 0.50 wt.% by weight of the mixture. In one example, the mixture is neutral or preferably alkaline. In one example, the mixture has a pH of at least 7, preferably at least 7.5, more preferably at least 8.0. Alkalinity of the mixture may arise from the addition of flux, for example.

In one example, the mixture consists of the particles including the ferrous material and the carbon material, optionally a flux for example MgO and/or CaO, the aqueous solution of the PVA and optionally a cross-linking agent, for example glutaraldehyde and/or borax.

Forming

The mixture is formed, thereby providing the agglomerate precursor.

In one example, the mixture is formed using compression for example by roller pressing, by die pressing (including die variants such as rotating table pressing), extrusion and/or a pan or disc pelletising.

In one example the mixture is formed into a briquette, having a dimension in a range from 25 mm to 100 mm.

In one example the mixture is formed into a pellet, having a maximum dimension of 25 mm. Curing

The method comprises curing the agglomerate precursor, thereby providing the agglomerate. By curing the agglomerate precursor, a strength, for example compressive strength, thereof may be increased, as described below in more detail.

In one example, the method comprises adding a cross-linking agent to the binder to promote cross-linking of the PVA to further improve bonding forces between the PVA polymer chains. A suitable cross-linking agent is glutaraldehyde and/or borax.

In one example, the providing the mixture comprises providing the ferrous material, at least in part, in the form of filter cake from a BOS process. Low level heat may be beneficial for the curing (a rate of gain of strength). Such low level heat may be obtained by including ferrous material in the form of filter cake from a BOS process in the mixture. Such filter cake includes iron oxides in a low oxidation state whereby further oxidation is strongly exothermic, thereby releasing heat. In one example, the providing the ferrous material, at least in part, in the form of filter cake from a BOS process comprises pre-blending the filter cake with thermally stable ferrous dusts. In order to control the rate of heating, the BOS cake is pre-blended with other thermally stable ferrous dusts, which absorb the excess heat and raise the overall temperature of the mix used in the agglomeration process.

In one example, the curing comprises heating the agglomerate precursor at a second temperature in a range from 50 °C to 250 °C, preferably from 75 °C to 200 °C, more preferably from 100 °C to 150 °C for a second duration in a range from 0.25 hours to 12 hours, preferably in a range from 0.5 hours to 3 hours, more preferably in a range from 0.75 hours to 1 .5 hours. In this way, a curing time of the agglomerate precursor may be shortened.

Flux

In one example, the particles include flux material, for example a MgO-containing flux and/or a CaO-containing flux. The flux material may be used to control, at least in part, different stages in the forming of the mixture and/or the curing of the agglomerate precursor. For example, CaO may increase a degree of -OH saturation of the PVA. Additionally and/or alternatively, the flux material may control, at least in part, the treating and/or the iron-making and/or steelmaking.

In one example, the method comprises adding MgO to the mixture to control, at least in part, a porosity and/or a strength of the agglomerate.

In one example, the method comprises adding CaMg(C03)2 (i.e. dolomite) and/or (Mg,Fe)2SiC>4 (i.e. olivine) to the mixture as a flux, thereby providing a MgO-containing flux and/or a CaO- containing flux.

Particle size

In one example, the method comprises providing the particles, for example by sieving (also known as screening) and/or comminution. In this way, a particle size and/or a particle size distribution of the particles may be controlled. Additionally and/or alternatively, clusters of particles may be declustered, thereby improving binding. The granularity (i.e. a particle size and/or a particle size distribution of the particles) of the ferrous material, the carbon material, and/or a flux material may be important. In one example, the particles including the ferrous material and the carbon material and/or optionally a flux material have a particle size of at most 5.0 mm. In one example, at least 50 wt.% of the particles have a particle size of at most 1 .0 mm, preferably at least 67 wt.% of the particles have a particle size of at most 1 .0 mm. Curing and treating

Curing of the agglomerate precursor and treating of the agglomerate may comprise three stages. The first two stages relate to the binder comprising an aqueous solution of PVA. The third stage relates to all binders.

The first stage takes place when the agglomerate is cured and involves -OH groups on the PVA polymer chain being attracted to other -OH groups on adjacent molecules or to the surface of the particles being bound. Although the bonding forces are described as‘weak hydrogen bonding’, this bonding is sufficient to impart very high cold compressive strength to the agglomerate precursor. Particularly, as the molecular chain lengths of the PVA are very long, the -OH groups present form a three dimensional matrix with intermolecular binding and molecular to particle binding. A cross-linking agent may improve the bonding and hence compressive strength of the agglomerate precursor.

The second stage takes place during heating of the agglomerate to the first temperature, particularly, as the temperature is elevated to and above a decomposition temperature of the PVA (about 200 °C). As the temperature increases further between 200 °C and 450 °C, OH- groups are stripped from the PVA polymer chain length, producing polyenes. Free radical reactions may then take place. Without wishing to be bound by any theory, it is thought that multi-valent metal ions present in the ferrous material act as catalysts in chain-scission and aromatic compound formation, producing oligomers present as char products. It is also thought that elemental carbon present in the agglomerate also takes part to a greater or lesser degree in complex organic chemistry making up the formation of the oligomer char products. The oligomer char products then form a thermally stable binding structure that is stable up to about 880 °C to 900 °C, when this binding structure breaks down and the carbon is burnt out.

The second stage takes place either during iron-making and/or steel-making processes, for example during use of the agglomerate in a BF or BOS process (i.e. included in a charge), for example, or during a separate thermal pre-treatment prior to the iron-making and/or steelmaking processes.

The third stage, of reduction (i.e. reducing oxidation states), takes place either during ironmaking and/or steel-making processes, for example during use of the agglomerate in a BF or BOS process (i.e. included in a charge), for example, or during a separate thermal pretreatment prior to the iron-making and/or steel-making processes.

The third stage, takes place during the heating at the first temperature for the first duration, primarily in an outer region of the agglomerate, forming a sintered hardened shell or surface layer. This third stage can be made to start before the second stage binding has failed. This is a function of the very fine iron oxide and carbon (micron particulates) in the agglomerate.

Within a BF process, for example, the reducing atmosphere encourages reduction within the outer shell of the agglomerate causing the formation of ‘spongy iron’ (also known as metallisation) which then continues to bind the agglomerate until the agglomerate becomes plastic as it reaches the melting zone within the furnace, where the flux addition aids final melt- out.

In contrast, during heating at the first temperature for the first duration in the presence of oxygen during a separate thermal pre-treatment prior to the iron-making and/or steel-making processes, an interior region of the agglomerate provides a reducing atmosphere despite the presence of oxygen outside of the agglomerate, due to the C content of the agglomerate in the range from 12.5 wt.% to 40 wt.%. This internally-reducing atmosphere within the agglomerate encourages reduction therein, resulting in reduction of undesirable metal oxides such as ZnO and/or PbO, and subsequent vaporisation of the undesirable metals such as Zn and/or Pb, as described below in more detail. Particularly, by elevating the C content of the agglomerate to the range from 12.5 wt.% to 40 wt.%, not only are the undesirable metal oxides reduced and the undesirable metals vapourised but there is also sufficient C to continue to provide the internally-reducing atmosphere to cause the formation of ‘spongy iron’ throughout the interior region of the agglomerate. In this way, the undesirable metals are removed and the agglomerate is partially or being to a high degree metallised with respect to Fe whereby there is a partial or high degree of metallisation throughout the agglomerate. By partially or to a high degree metallising the agglomerate with respect to Fe, less C is required to be included in a charge for the BF, for example, and/or iron-making and/or steel-making is more efficient. Since the undesirable metals are removed from the agglomerate, a quality of the iron or steel is also improved.

Iron and carbon

Iron oxides are reduced by CO and/or C, as detailed below.

In a temperature range above 450°C, the following reactions may occur:

3Fe203 + CO ® 2Fe30 ₄ + CO2

In a temperature range above 600°C, the following reactions may occur:

Fe3<D4 + CO ® 3FeO + CO2 In a temperature range above 700°C, the following reactions may occur:

FeO + CO ® Fe + CO2

FeO + C ® Fe + CO

The agglomerate before treating has the first composition comprising:

Fe in a range from 20 wt.% to 80 wt.%, preferably in a range from 30 wt.% to 70 wt.%, more preferably in a range from 35 wt.% to 65 wt.% by weight of the agglomerate; and

C in a range from 12.5 wt.% to 40 wt.%, preferably in a range from 14 wt.% to 25 wt.%, more preferably in a range from 15 wt.% to 20 wt.% by weight of the agglomerate; and

the agglomerate after treating has the second composition comprising:

Fe in a range from 30 wt.% to 90 wt.%, preferably in a range from 35 wt.% to 85 wt.%, more preferably in a range from 40 wt.% to 80 wt.% by weight of the agglomerate; and

C in a range from 0.0 wt.% to 9 wt.%, preferably in a range from 0.01 wt.% to 5 wt.%, more preferably in a range from 0.1 wt.% to 1 wt.% by weight of the agglomerate.

It is preferable to increase and/or optimise and/or maximise the amount of Fe of the agglomerate before treating (i.e. generally Fe oxides, particularly Fe30 ₄ and/or Fe ₂ C>3, as described above) to increase and/or optimise and/or maximise the elemental Fe content of the agglomerate after treating. Hence, C is included in the agglomerate before treating in an amount to provide reduction of the Fe oxides, for example to reduce at least 50 wt.%, preferably at least 60 wt.%, more preferably at least 70 wt.%, even more preferably at least 80 wt.%, most preferably at least 90 wt.%, 95 wt.% or 97.5 wt.% by weight of the Fe oxides. In addition, as described below, C is included in the agglomerate before treating also in an amount to provide reduction of oxides of undesirable elements. If the amount of C included in the agglomerate before treating is too low for the amount of oxides included therein, reduction of the oxides is incomplete and efficiency of reduction is degraded. If the amount of C included in the agglomerate before treating is too high for the amount of oxides included therein, excess C may be burned without providing further useful reduction of the oxides, thereby degrading an efficiency. It is preferable that most or all of the C is reacted in reduction of oxides during the treating, such that the amount of C remaining in the agglomerate after treating is minimised, so as to enhance efficiency of reduction. Additionally and/or alternatively, if the amount of C included in the agglomerate before treating is too high, a strength of the agglomerate precursor and/or agglomerate may be too low for handling, for example. Removal of undesirable elements

Recycling of ferrous waste material including undesirable elements, for example volatile metals (i.e. having relatively low melting points compared with Fe) such as Sn, Pb, Zn and/or alkali metals including Li, Na and K, may be detrimental to, and/or adversely affect efficiencies of, the steel-making and iron-making processes and/or comprise impurities in steel or iron. For example, volatilization and subsequent condensation and solidification of such metals, particularly Zn, in a blast furnace, for example, may be cyclical such that the metals circulate. That is, Zn, for example, may volatilize, condense and solidify, forming scabs, on relatively cooler surfaces of the blast furnace, as described below in more detail. The scabs may then fall into relatively hotter regions of the blast furnace and revolatilize. Hence, this circulation continues. If the scabs fall into the liquid iron or steel, the Zn may be retained therein as an undesirable impurity. Hence, a separate thermal pre-treatment of the agglomerate prior to the iron-making and/or steel-making processes is preferred. In this way, one or more of these undesirable elements may be removed, and/or an amount thereof decreased, from the ironmaking and/or steel-making processes. In one example, the treating the agglomerate comprises and/or is a thermal pre-treatment of the agglomerate, comprising the heating the agglomerate, as described herein. The treating the agglomerate comprises heating the agglomerate in the presence of oxygen at the first temperature in a range from 1050 °C to 1400 °C, preferably from 1100 °C to 1300 °C, more preferably from 1150 °C to 1250 °C for the first duration in a range from 0.25 hours to 12 hours, preferably in a range from 0.5 hours to 3 hours, more preferably in a range from 0.75 hours to 1.5 hours.

In this way, such heating vaporises metals having melting points at or below the first temperature, such as Sn, Pb, Zn and/or alkali metals including Li, Na and K, and/or the other undesirable elements. These vaporised metals may be subsequently collected, for example from off gas.

Zinc

Zn may be introduced (i.e. as a non-deliberate addition) into iron-making and/or steel-making via iron ore as an oxide (ZnO) or zinc ferrite (ZnO-Fe ₂ C>3), silicate and/or sulphide. Zn may also be introduced as recycled waste products as an oxide and/or ferrite and also as galvanised (zinc coated) scrap metal introduced into the BOS process. Without wishing to be bound by any theory, it is thought that at relatively high temperatures, for example at least 1000 °C, these Zn compounds (mostly transformed to the oxide) may be reduced by CO and carbon to Zn metal (as vapour). The following reactions indicate possible metallisation routes for Zn through reduction of ZnO 0r ZnO Fe ₂ O3 with CO gas or C:

ZnO + CO ® Zn + CO2

AG (1473 K) = 13.643 kJ; DH (1473 K) = 185.317 kJ

ZnO + C ® Zn + CO

AG (1473 K) = -73.017 kJ; AH (1473 K) = 345.858 kJ

Zn0-Fe203 + 4CO ® Zn + 2Fe + 4CO2

AG (1473 K) = 21 .274 kJ; AH (1473 K) = 163.003 kJ

Zn0-Fe203 + 4C ® Zn + 2Fe + 4CO

AG (1473 K) = -325.366 kJ; AH (1473 K) = 824.791 kJ

Hence, reduction of ZnO and Zn0-Fe ₂ 03 by C is more thermodynamically favourable than by CO gas at 1473 K. Both reductions are highly endothermic and hence higher temperatures may favour both. However, an extent of reduction may depend on activity of ZnO in the compound, for example. A higher activity of ZnO may favour metallisation of Zn.

However, at relatively lower temperatures, for example 800 °C to 1000 °C, while ZnO may be reduced by CO to produce Zn, competing reaction of Zn with CO2 produces ZnO:

ZnO + CO ® Zn + CO2

Zn + CO2 ® ZnO + CO

Production of Zn vapour in a lower, hotter zone of a blast furnace, for example, is problematic in that the Zn condenses in an upper, cooler part of the blast furnace, where the temperature is lower than a boiling point of Zn (907 °C), normally starting at 520 °C to 580 °C. In addition, Zn vapour may be reoxidized back to ZnO in the upper part when temperature is below 900 °C, and the ZnO may become part of the flue dust (i.e. discharged particles), which is carried by the off gas (also known as top gas), which may form build-ups in the throat and off-takes. The condensation of Zn and ZnO may take place on the burden and coke surfaces, which block pores therein and reduce gas permeability. This may cause an increase in coke rate and decrease in productivity. Some Zn vapour may penetrate through brick joints in the lining and condense around cooling plates as metal. ZnO may also descend to the lower, hotter zone and be reduced again, giving a Zn circulation zone in the blast furnace. The circulation zone may occupy an entire dry part of the shaft and part of the cohesive zone. Zinc circulation within the blast furnace is thus detrimental to blast furnace operation while production of Zn-bearing flue dust is environmentally damaging.

Hence, the Zn content of the agglomerate is decreased by the treating, such that the second amount of Zn is less than the first amount of Zn. Particularly, the Zn content of the agglomerate is decreased from the first amount of Zn in a range from 0.10 wt.% to 10.0 wt.%, preferably in a range from 0.29 wt.% to 7.0 wt.%, more preferably in a range from 0.30 wt.% to 4.0 wt.%, most preferably in a range from 0.35 wt.% to 2.0 wt.% by weight of the agglomerate to the second amount of Zn in a range from 0.0 wt.% to 1 .0 wt.%, preferably in a range from 0.001 wt.% to 0.5 wt.%, more preferably in a range from 0.01 wt.% to 0.1 wt.% by weight of the agglomerate.

Hence, the agglomerate before treating has the first composition comprising:

a first amount of Zn in a range from 0.10 wt.% to 10.0 wt.%, preferably in a range from 0.29 wt.% to 7.0 wt.%, more preferably in a range from 0.30 wt.% to 4.0 wt.%, most preferably in a range from 0.35 wt.% to 2.0 wt.% by weight of the agglomerate; and

the agglomerate after treating has the second composition comprising:

a second amount of Zn in a range from 0.0 wt.% to 1 .0 wt.%, preferably in a range from 0.001 wt.% to 0.5 wt.%, more preferably in a range from 0.01 wt.% to 0.1 wt.% by weight of the agglomerate;

wherein the second amount of Zn is less than the first amount of Zn.

That is, even relatively high amounts of Zn, for example in a range from 0.29 wt.% to 7.0 wt.% or 10 wt.%, may be removed effectively, or an amount thereof decreased significantly, from the agglomerate by the treating. The inventors have determined that this removal or reduction is due, at least in part, to the relatively high C content of the agglomerate before treating, particularly C in a range from 12.5 wt.% to 40 wt.%, preferably in a range from 14 wt.% to 25 wt.%, more preferably in a range from 15 wt.% to 20 wt.% by weight of the agglomerate.

Known agglomerates subject to similar methods of treatment are restricted to only relatively lower C contents. In these known agglomerates, the role of C is to make the agglomerates partially self-reducing to give a metallization level of ~30%. A C content of 8 wt.% to 12 wt.% by weight of the agglomerate is conventionally considered a maximum thereof.

That is, a relationship between the C of the agglomerate and the amount of Zn that may be removed therefrom was not previously known. In contrast, the inventors have determined that by increasing the C content of the agglomerate to a range from 12.5 wt.% to 40 wt.%, relatively higher amounts of Zn may be removed or decreased while all of the C is still consumed during the third stage. That is, the increased C content is not detrimental to the third stage and is instead beneficial to the second stage.

Without wishing to be bound by any theory, it is thought that the increased C content provides improved self-reducing properties to the agglomerate even during the second stage, thereby reducing compounds of the undesirable metals to elemental form. Additionally and/or alternatively, it is thought that increased reduction of oxides, for example ZnO, by C results in an increased amount of CO produced that further contributes to reduction of the oxides by reaction therewith. Additionally and/or alternatively, it is thought that the increased C content, due to an increased proportion of carbon material, increases porosity of the agglomerate, thereby facilitating vaporization of the Zn and/or other undesirable metals.

In one example, a ratio of the second amount of Zn to the first amount of Zn is in a range from 1 : 5 to 1 : 10,000, preferably in a range from 1 : 10 to 1 : 1 ,000, more preferably in a range from 1 : 20 to 1 : 500, most preferably in a range from 1 : 40 to 1 : 100. In this way, the Zn content of the agglomerate may be effectively decreased or removed.

Strength

A strength of the agglomerate precursor and/or the agglomerate is not adversely affected by the increased C content thereof, such that sufficient strength is retained, for example for handling and/or during treating. This is contrary to conventional understanding.

Without wishing to be bound by any theory, it is thought that the increased C content, due to an increased proportion of carbon material, increases bonding therebetween due to the binder during curing. Hence, while the carbon material may contribute a relatively lower compressive strength than the ferrous material to the agglomerate in an absence of the binder, the three dimensional matrix, as described above, may be reinforced due to the increased C content.

Pb

Pb may be introduced into iron-making and/or steel-making via iron ore as an oxide (PbO) and/or sulphate (PbSC ) and/or sulphide (PbS). Pb may also be introduced via recycled waste products as PbO and/or PbS0 ₄ and/or PbS. These Pb compounds are reduced in the upper part of the blast furnace. Since Pb is insoluble in iron and has higher density than both the hot metal and slag, Pb flows down and accumulates in the hearth. Although metallic Pb has a low vapour pressure, some Pb may vaporize and condense in the upper part of the blast furnace on the burden or lining material. Some Pb may also leave with the top gas to the dust or sludge fraction. Thus, similar to Zn, Pb may also circulate. In a temperature range from 400 °C to 700 °C, the following reactions may occur:

PbO + CO ® Pb + C0 ₂

2PbO + S1O2 ® PbSi0 ₄

In a temperature range from 650 °C to 900 °C, the following reactions may occur:

PbS0 ₄ + 4C ® PbS + 4CO

PbS0 ₄ + PbS ® 2Pb + 2S0 ₂

In a temperature range from 1000 °C to 1200 °C, the following reaction may occur:

PbS + C + CaO ® CaS + CO + Pb

In one example:

the first composition comprises a first amount of Pb in a range from 0.16 wt.% to 5.0 wt.%, preferably in a range from 0.18 wt.% to 3.0 wt.%, more preferably in a range from 0.20 wt.% to 2.0 wt.%, most preferably in a range from 0.22 wt.% to 1 .0 wt.% by weight of the agglomerate; the second composition comprises a second amount of Pb in a range from 0.0 wt.% to 1 .0 wt.%, preferably in a range from 0.001 wt.% to 0.5 wt.%, more preferably in a range from 0.01 wt.% to 0.1 wt.% by weight of the agglomerate; and

the second amount of Pb is less than the first amount of Pb.

In this way, the Pb content of the agglomerate is decreased by the treating, such that the second amount of Pb is less than the first amount of Pb. Reduction in the Pb content of the agglomerate may be as described with respect to Zn.

In one example, a ratio of the second amount of Pb to the first amount of Pb is in a range from 1 : 5 to 1 : 10,000, preferably in a range from 1 : 10 to 1 : 1 ,000, more preferably in a range from 1 : 15 to 1 : 500, most preferably in a range from 1 : 20 to 1 : 100. In this way, the Pb content of the agglomerate may be effectively decreased or removed.

Alkali metals

Alkali metals, particularly Na and K, may be introduced into iron-making and/or steel-making as complex silicates in the ferrous burden, coke, coal and in slag forming materials. Alkali silicates descend with the charged material and dissolve in the primary melt formed in the cohesive zone.

Alkali silicates may be reduced by C to alkali metal vapour (Na similarly to K below):

K2S1O3 + C ® 2K + S1O2 + CO

K2S1O3 + 3C ® 2K + Si + 3CO

Alkali oxides may be reduced by C or CO to alkali metal vapour (Na similarly to K below):

K2O + C ® 2K + CO

K2O + CO ® 2K + CO2

Alkalis are volatilized as elements or react with nitrogen and carbon in the bosh region forming KCN and/or NaCN vapour. These gases may be carried with the furnace gas and do not dissolve in the hot metal or into the slag.

Na and K particularly may influence iron-making and/or steel-making, for example blast furnace operation. Enrichment of these alkali metals may be a catalyst for coke gasification and is therefore a key parameter in degradation of coke in the lower part of the blast furnace. K also directly destroys the carbon structure and minerals while Na vapours mainly catalyse coke gasification. The enrichment of these alkali metals increases in the lower part of the blast furnace where the temperature is above 1000 °C. These alkali metals may cause the formation of scabs (also known as scaffolds), which are a build-up of solid material on furnace walls that project inwards. These alkali metals may attack blast furnace refractory materials, especially carbon-based refractories used in the lower part of the blast furnace, reducing a lifetime thereof.

The inventors have further determined that by increasing the C content of the agglomerate to a range from 12.5 wt.% to 40 wt.%, a content of alkali metals, particularly Na and K, may also be effectively decreased during the treating. This is also contrary to conventional understanding. Particularly, while at least partial removal of such alkali metals has been previously postulated, even a C content of 8 wt.% to 12 wt.% is not effective for removal thereof. In contrast, beneficial reductions in the amounts of Na and/or K are obtained by the treating. In one example:

the first composition comprises a first amount of Na in a range from 0.01 wt.% to 3.0 wt.%, preferably in a range from 0.02 wt.% to 3.0 wt.%, more preferably in a range from 0.05 wt.% to 1 .0 wt.%, most preferably in a range from 0.10 wt.% to 0.50 wt.% by weight of the agglomerate;

the second composition comprises a second amount of Na in a range from 0.0 wt.% to 1 .0 wt.%, preferably in a range from 0.001 wt.% to 0.5 wt.%, more preferably in a range from 0.01 wt.% to 0.25 wt.% by weight of the agglomerate; and

the second amount of Na is less than the first amount of Na.

In this way, the Na content of the agglomerate is decreased by the treating, such that the second amount of Na is less than the first amount of Na. Reduction in the Na content of the agglomerate may be as described with respect to Zn. In one example, a ratio of the second amount of Na to the first amount of Na is in a range from 1 : 5 to 1 : 10,000, preferably in a range from 1 : 10 to 1 : 1 ,000, more preferably in a range from 1 : 15 to 1 : 500, most preferably in a range from 1 : 20 to 1 : 100. In this way, the Na content of the agglomerate may be effectively decreased or removed. In one example:

the first composition comprises a first amount of K in a range from 0.05 wt.% to 3.0 wt.%, preferably in a range from 0.10 wt.% to 3.0 wt.%, more preferably in a range from 0.15 wt.% to 1 .0 wt.%, most preferably in a range from 0.20 wt.% to 0.50 wt.% by weight of the agglomerate;

the second composition comprises a second amount of K in a range from 0.0 wt.% to 1 .0 wt.%, preferably in a range from 0.001 wt.% to 0.5 wt.%, more preferably in a range from 0.01 wt.% to 0.25 wt.% by weight of the agglomerate; and

the second amount of K is less than the first amount of K. In this way, the K content of the agglomerate is decreased by the treating, such that the second amount of K is less than the first amount of K. Reduction in the K content of the agglomerate may be as described with respect to Zn.

In one example, a ratio of the second amount of K to the first amount of K is in a range from 1 : 5 to 1 : 10,000, preferably in a range from 1 : 10 to 1 : 1 ,000, more preferably in a range from 1 : 15 to 1 : 500, most preferably in a range from 1 : 20 to 1 : 100. In this way, the K content of the agglomerate may be effectively decreased or removed. Other metals

The inventors have further determined that by increasing the C content of the agglomerate to a range from 12.5 wt.% to 40 wt.%, a content of other first, second and/or third row transition metals may also be effectively decreased during the treating. First row transition metals include Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu or Zn. Second row transition metals include Y, Zr, Nb, Mo, Tc, Ru, Rh, Pd, Ag or Cd. Third row transition metals include Hf, Ta, W, Re, Os, Ir, Pt, Au or Hg. Chromium

Cr ₂ 03 may be reduced by C to Cr at temperatures of about 1220 °C:

Cr203 + 3C ® 2Cr + 3CO

Cobalt

C03O ₄ may be reduced by C to Co at temperatures of at least 900 °C: C03O4 + 4C ® 3Co + 4CO

C03O4 + 4CO ® 3Co + 4CO2

Nickel

NiO may be reduced by CO to Ni temperatures of about 1220 °C:

NiO + CO ® Ni + CO2 Cadmium

CdO may be reduced by CO to Cd at relatively low temperatures. However, Cd may react with CI2 at temperatures below 1000 °C and leave the blast furnace with the top gas as CdCh. Cd may also react with S to produce CdS, which is able to rise with the gas stream in the blast furnace. At lower temperature zones at which O2 is present, it can be oxidized or solidify and get to zones of higher temperatures. Thus Cd, like Zn and Pb, may also circulate.

In one example: the first composition comprises a first amount of Cd in a range from 250 ppm to 5 ppm, preferably in a range from 200 ppm to 10 ppm, more preferably in a range from 150 ppm to 15 ppm, most preferably in a range from 100 ppm to 20 ppm by weight of the agglomerate;

the second composition comprises a second amount of Cd in a range from 0.00 ppm to 50 ppm, preferably in a range from 0.01 ppm to 25 ppm, more preferably in a range from 0.1 ppm to 10 ppm by weight of the agglomerate; and

the second amount of Cd is less than the first amount of Cd.

In this way, the Cd content of the agglomerate is decreased by the treating, such that the second amount of Cd is less than the first amount of Cd. Reduction in the Cd content of the agglomerate may be as described with respect to Zn.

In one example, a ratio of the second amount of Cd to the first amount of Cd is in a range from 1 : 5 to 1 : 10,000, preferably in a range from 1 : 10 to 1 : 1 ,000, more preferably in a range from 1 : 15 to 1 : 500, most preferably in a range from 1 : 20 to 1 : 100. In this way, the Cd content of the agglomerate may be effectively decreased or removed.

Mercury

HgS may be reduced to Hg by O2:

HgS + O2 ® Hg + SO2

However, HgS also moves downward to zones having temperatures of at least 800 C, where HgS enters into the liquid state and is reduced. The metallic Hg produced vaporizes and rises with the reducing gas.

In one example, the agglomerate before treating has the first composition comprising a first amount of Ca in a range from 0.01 wt.% to 10.0 wt.%, preferably in a range from 0.02 wt.% to 9.0 wt.%, more preferably in a range from 0.05 wt.% to 8.0 wt.%, most preferably in a range from 0.10 wt.% to 7.0 wt.% by weight of the agglomerate.

In one example, the agglomerate before treating has the first composition comprising a first amount of Si in a range from 0.01 wt.% to 10.0 wt.%, preferably in a range from 0.02 wt.% to 9.0 wt.%, more preferably in a range from 0.05 wt.% to 8.0 wt.%, most preferably in a range from 0.10 wt.% to 7.0 wt.% by weight of the agglomerate.

In one example, the agglomerate before treating has the first composition comprising a first amount of Mn in a range from 0.01 wt.% to 5.0 wt.%, preferably in a range from 0.02 wt.% to 4.0 wt.%, more preferably in a range from 0.05 wt.% to 3.0 wt.%, most preferably in a range from 0.10 wt.% to 2.0 wt.% by weight of the agglomerate.

In one example, the agglomerate before treating has the first composition comprising a first amount of Al in a range from 0.01 wt.% to 5.0 wt.%, preferably in a range from 0.02 wt.% to 4.0 wt.%, more preferably in a range from 0.05 wt.% to 3.0 wt.%, most preferably in a range from 0.10 wt.% to 2.0 wt.% by weight of the agglomerate.

In one example, the agglomerate before treating has the first composition comprising a first amount of Mg in a range from 0.01 wt.% to 5.0 wt.%, preferably in a range from 0.02 wt.% to 4.0 wt.%, more preferably in a range from 0.05 wt.% to 3.0 wt.%, most preferably in a range from 0.10 wt.% to 2.0 wt.% by weight of the agglomerate.

In one example, the agglomerate before treating has the first composition comprising first amounts of P and/or S in a range from 0.05 wt.% to 3.0 wt.%, preferably in a range from 0.10 wt.% to 3.0 wt.%, more preferably in a range from 0.15 wt.% to 1 .0 wt.%, most preferably in a range from 0.20 wt.% to 0.50 wt.% by weight of the agglomerate.

In one example, the agglomerate before treating has the first composition comprising a first amount of Ti in a range from 0.05 wt.% to 3.0 wt.%, preferably in a range from 0.10 wt.% to 3.0 wt.%, more preferably in a range from 0.15 wt.% to 1 .0 wt.%, most preferably in a range from 0.20 wt.% to 0.50 wt.% by weight of the agglomerate.

In one example, the agglomerate before treating has the first composition comprising first amounts of Ni, Cu, Cr, Ba, Zr, Sr, Mo, Hf and/or Co in a range from 0.001 wt.% to 1 .0 wt.%, preferably in a range from 0.005 wt.% to 0.5 wt.%, more preferably in a range from 0.01 wt.% to 0.1 wt.%, most preferably in a range from 0.02 wt.% to 0.05 wt.% by weight of the agglomerate.

In one example, the agglomerate before treating has the first composition comprising first amounts of Li, As, Sb, Hg, Br and/or Cl in a range from 250 ppm to 0.1 ppm, preferably in a range from 100 ppm to 0.2 ppm, more preferably in a range from 50 ppm to 0.5 ppm, most preferably in a range from 30 ppm to 1 ppm by weight of the agglomerate.

In one example, the agglomerate after treating has the second composition comprising a second amount of Ca in a range from 0.01 wt.% to 10.0 wt.%, preferably in a range from 0.02 wt.% to 9.0 wt.%, more preferably in a range from 0.05 wt.% to 8.0 wt.%, most preferably in a range from 0.10 wt.% to 7.0 wt.% by weight of the agglomerate. In one example, the agglomerate after treating has the second composition comprising a second amount of Si in a range from 0.01 wt.% to 10.0 wt.%, preferably in a range from 0.02 wt.% to 9.0 wt.%, more preferably in a range from 0.05 wt.% to 8.0 wt.%, most preferably in a range from 0.10 wt.% to 7.0 wt.% by weight of the agglomerate.

In one example, the agglomerate after treating has the second composition comprising a second amount of Mn in a range from 0.01 wt.% to 5.0 wt.%, preferably in a range from 0.02 wt.% to 4.0 wt.%, more preferably in a range from 0.05 wt.% to 3.0 wt.%, most preferably in a range from 0.10 wt.% to 2.0 wt.% by weight of the agglomerate.

In one example, the agglomerate after treating has the second composition comprising a second amount of Al in a range from 0.01 wt.% to 5.0 wt.%, preferably in a range from 0.02 wt.% to 4.0 wt.%, more preferably in a range from 0.05 wt.% to 3.0 wt.%, most preferably in a range from 0.10 wt.% to 2.0 wt.% by weight of the agglomerate.

In one example, the agglomerate after treating has the second composition comprising a second amount of Mg in a range from 0.01 wt.% to 5.0 wt.%, preferably in a range from 0.02 wt.% to 4.0 wt.%, more preferably in a range from 0.05 wt.% to 3.0 wt.%, most preferably in a range from 0.10 wt.% to 2.0 wt.% by weight of the agglomerate.

In one example, the agglomerate after treating has the second composition comprising second amounts of P and/or S in a range from 0.05 wt.% to 3.0 wt.%, preferably in a range from 0.10 wt.% to 3.0 wt.%, more preferably in a range from 0.15 wt.% to 1 .0 wt.%, most preferably in a range from 0.20 wt.% to 0.50 wt.% by weight of the agglomerate.

In one example, the agglomerate after treating has the second composition comprising a second amount of Ti in a range from 0.05 wt.% to 3.0 wt.%, preferably in a range from 0.10 wt.% to 3.0 wt.%, more preferably in a range from 0.15 wt.% to 1 .0 wt.%, most preferably in a range from 0.20 wt.% to 0.50 wt.% by weight of the agglomerate.

In one example, the agglomerate after treating has the second composition comprising second amounts of Ni, Cu, Cr, Ba, Zr, Sr, Mo, Hf and/or Co in a range from 0.001 wt.% to 1 .0 wt.%, preferably in a range from 0.005 wt.% to 0.5 wt.%, more preferably in a range from 0.01 wt.% to 0.1 wt.%, most preferably in a range from 0.02 wt.% to 0.05 wt.% by weight of the agglomerate.

In one example, the agglomerate after treating has the second composition comprising second amounts of Li, As, Sb, Hg, Br and/or Cl in a range from 250 ppm to 0.1 ppm, preferably in a range from 100 ppm to 0.2 ppm, more preferably in a range from 50 ppm to 0.5 ppm, most preferably in a range from 30 ppm to 1 ppm by weight of the agglomerate.

In one example, the second amount of Cl is less than the first amount of Cl.

Cl in a BF

Typically, Cl may be present in a BF, for example, as HCI, NFUCI and/or metal salts, for example alkali metal chlorides such as NaCI and/or KCI and/or transition metal chlorides such as ZnCI. Cl may be introduced into a blast furnace as chloride species and/or organic speciation absorbed in coke, for example. This Cl reacts with the BF gas to form HCI. At elevated HCL concentrations, reactivity of the coke decreases such that reduction of iron ore is impeded.

Without wishing bound by any theory, thermodynamic calculations suggest that Cl may accumulate and cycle in a shaft of the BF, particularly in the form of alkali metal chlorides. Superposition of two cycles has been postulated: a pure alkali metals cycle over a larger temperature range, and specific cycle, for example a KCI cycle, in a narrower temperature range from about 600 °C to about 1 ,000 °C.

Cl in the top gas results in corrosion of pipes, hot stoves and tuyeres. Cl in the hearth results in erosion thereof.

Hence, it is desirable to remove Cl from the agglomerate.

In one example, the agglomerate before treating has the first composition comprising a first amount of Cl in a range from 250 ppm to 0.1 ppm, preferably in a range from 100 ppm to 0.2 ppm, more preferably in a range from 50 ppm to 0.5 ppm, most preferably in a range from 30 ppm to 1 ppm by weight of the agglomerate.

In one example, the agglomerate after treating has the second composition comprising a second amount of Cl in a range from 250 ppm to 0.1 ppm, preferably in a range from 100 ppm to 0.2 ppm, more preferably in a range from 50 ppm to 0.5 ppm, most preferably in a range from 30 ppm to 1 ppm by weight of the agglomerate.

In one example, the second amount of Cl is less than the first amount of Cl.

Kiln In one example, the heating the agglomerate in the presence of oxygen at the first temperature for the first duration is performed in a furnace, a rotary kiln, for example a cement kiln, and/or in a continuous kiln, for example a tunnel kiln.

Advantageously, since the heating is in a presence of oxygen, such open kilns may be used, thereby decreasing a cost and/or complexity of the treating and/or increasing a throughput therethrough.

Fractions

In one example, the method comprises screening, for example sieving, the agglomerate after the treatment into a first fraction for use in sinter making, a second fraction for use in a blast furnace process and optionally, a third fraction for use in a basic oxygen steelmaking process.

As described previously, briquettes are preferred, since they may be included relatively further downstream in iron-making and/or steel-making processes, thereby adding further value. For example, agglomerates having a maximum dimension of at most about 6 mm (i.e. a first fraction) are generally only suitable for sinter production. For example, agglomerates having a maximum dimension in a range from about 6 mm to about 45 mm (i.e. a second fraction) are suitable for inclusion in a BF charge. For example, agglomerates having a maximum dimension of at least about 45 mm (i.e. a third fraction) may be used in a BOS process, for example as a coolant.

Recovery

In one example, the method comprises recovering at least some of the Zn and/or Pb during the treating. Other metals may also be similarly recovered.

In this way, the Zn and/or Pb may be recycled for other metallurgical processes, thereby also reducing disposal thereof.

Preferred compositions

In one example, the agglomerate before treating has the first composition comprising and/or consisting of:

Fe in a range from 20 wt.% to 80 wt.%, preferably in a range from 30 wt.% to 70 wt.%, more preferably in a range from 35 wt.% to 65 wt.% by weight of the agglomerate;

C in a range from 12.5 wt.% to 40 wt.%, preferably in a range from 14 wt.% to 25 wt.%, more preferably in a range from 15 wt.% to 20 wt.% by weight of the agglomerate; a first amount of Zn in a range from 0.10 wt.% to 10.0 wt.%, preferably in a range from 0.29 wt.% to 7.0 wt.%, more preferably in a range from 0.30 wt.% to 4.0 wt.%, most preferably in a range from 0.35 wt.% to 2.0 wt.% by weight of the agglomerate;

optionally, a first amount of Pb in a range from 0.16 wt.% to 5.0 wt.%, preferably in a range from 0.18 wt.% to 3.0 wt.%, more preferably in a range from 0.20 wt.% to 2.0 wt.%, most preferably in a range from 0.22 wt.% to 1 .0 wt.% by weight of the agglomerate;

optionally, a first amount of Na in a range from 0.01 wt.% to 3.0 wt.%, preferably in a range from 0.02 wt.% to 3.0 wt.%, more preferably in a range from 0.05 wt.% to 1 .0 wt.%, most preferably in a range from 0.10 wt.% to 0.50 wt.% by weight of the agglomerate;

optionally, a first amount of K in a range from 0.05 wt.% to 3.0 wt.%, preferably in a range from

0.10 wt.% to 3.0 wt.%, more preferably in a range from 0.15 wt.% to 1 .0 wt.%, most preferably in a range from 0.20 wt.% to 0.50 wt.% by weight of the agglomerate;

optionally, a first amount of Cd in a range from 250 ppm to 5 ppm, preferably in a range from 200 ppm to 10 ppm, more preferably in a range from 150 ppm to 15 ppm, most preferably in a range from 100 ppm to 20 ppm by weight of the agglomerate;

optionally, a first amount of Ca in a range from 0.01 wt.% to 10.0 wt.%, preferably in a range from 0.02 wt.% to 9.0 wt.%, more preferably in a range from 0.05 wt.% to 8.0 wt.%, most preferably in a range from 0.10 wt.% to 7.0 wt.% by weight of the agglomerate;

optionally, a first amount of Si in a range from 0.01 wt.% to 10.0 wt.%, preferably in a range from 0.02 wt.% to 9.0 wt.%, more preferably in a range from 0.05 wt.% to 8.0 wt.%, most preferably in a range from 0.10 wt.% to 7.0 wt.% by weight of the agglomerate;

optionally, a first amount of Mn in a range from 0.01 wt.% to 5.0 wt.%, preferably in a range from 0.02 wt.% to 4.0 wt.%, more preferably in a range from 0.05 wt.% to 3.0 wt.%, most preferably in a range from 0.10 wt.% to 2.0 wt.% by weight of the agglomerate;

optionally, a first amount of Al in a range from 0.01 wt.% to 5.0 wt.%, preferably in a range from 0.02 wt.% to 4.0 wt.%, more preferably in a range from 0.05 wt.% to 3.0 wt.%, most preferably in a range from 0.10 wt.% to 2.0 wt.% by weight of the agglomerate;

optionally, a first amount of Mg in a range from 0.01 wt.% to 5.0 wt.%, preferably in a range from 0.02 wt.% to 4.0 wt.%, more preferably in a range from 0.05 wt.% to 3.0 wt.%, most preferably in a range from 0.10 wt.% to 2.0 wt.% by weight of the agglomerate;

optionally, first amounts of P and/or S in a range from 0.05 wt.% to 3.0 wt.%, preferably in a range from 0.10 wt.% to 3.0 wt.%, more preferably in a range from 0.15 wt.% to 1 .0 wt.%, most preferably in a range from 0.20 wt.% to 0.50 wt.% by weight of the agglomerate;

optionally, a first amount of Ti in a range from 0.05 wt.% to 3.0 wt.%, preferably in a range from

0.10 wt.% to 3.0 wt.%, more preferably in a range from 0.15 wt.% to 1 .0 wt.%, most preferably in a range from 0.20 wt.% to 0.50 wt.% by weight of the agglomerate;

optionally, first amounts of Ni, Cu, Cr, Ba, Zr, Sr, Mo, Hf and/or Co in a range from 0.001 wt.% to 1 .0 wt.%, preferably in a range from 0.005 wt.% to 0.5 wt.%, more preferably in a range from 0.01 wt.% to 0.1 wt.%, most preferably in a range from 0.02 wt.% to 0.05 wt.% by weight of the agglomerate; and

optionally, first amounts of Li, As, Sb, Hg, Br and/or Cl in a range from 250 ppm to 0.1 ppm, preferably in a range from 100 ppm to 0.2 ppm, more preferably in a range from 50 ppm to 0.5 ppm, most preferably in a range from 30 ppm to 1 ppm by weight of the agglomerate; and balance oxygen, water and unavoidable impurities.

In one example, the agglomerate after treating has the second composition comprising and/or consisting of:

Fe in a range from 30 wt.% to 90 wt.%, preferably in a range from 35 wt.% to 85 wt.%, more preferably in a range from 40 wt.% to 80 wt.% by weight of the agglomerate;

C in a range from 0.0 wt.% to 9 wt.%, preferably in a range from 0.01 wt.% to 5 wt.%, more preferably in a range from 0.1 wt.% to 1 wt.% by weight of the agglomerate;

a second amount of Zn in a range from 0.0 wt.% to 1 .0 wt.%, preferably in a range from 0.001 wt.% to 0.5 wt.%, more preferably in a range from 0.01 wt.% to 0.1 wt.% by weight of the agglomerate;

optionally, a second amount of Pb in a range from 0.0 wt.% to 1 .0 wt.%, preferably in a range from 0.001 wt.% to 0.5 wt.%, more preferably in a range from 0.01 wt.% to 0.1 wt.% by weight of the agglomerate;

optionally, a second amount of Na in a range from 0.0 wt.% to 1 .0 wt.%, preferably in a range from 0.001 wt.% to 0.5 wt.%, more preferably in a range from 0.01 wt.% to 0.25 wt.% by weight of the agglomerate;

optionally, a second amount of K in a range from 0.0 wt.% to 1 .0 wt.%, preferably in a range from 0.001 wt.% to 0.5 wt.%, more preferably in a range from 0.01 wt.% to 0.25 wt.% by weight of the agglomerate;

optionally, a second amount of Cd in a range from 0.00 ppm to 50 ppm, preferably in a range from 0.01 ppm to 25 ppm, more preferably in a range from 0.1 ppm to 10 ppm by weight of the agglomerate;

optionally, a second amount of Ca in a range from 0.01 wt.% to 10.0 wt.%, preferably in a range from 0.02 wt.% to 9.0 wt.%, more preferably in a range from 0.05 wt.% to 8.0 wt.%, most preferably in a range from 0.10 wt.% to 7.0 wt.% by weight of the agglomerate;

optionally, a second amount of Si in a range from 0.01 wt.% to 10.0 wt.%, preferably in a range from 0.02 wt.% to 9.0 wt.%, more preferably in a range from 0.05 wt.% to 8.0 wt.%, most preferably in a range from 0.10 wt.% to 7.0 wt.% by weight of the agglomerate;

optionally, a second amount of Mn in a range from 0.01 wt.% to 5.0 wt.%, preferably in a range from 0.02 wt.% to 4.0 wt.%, more preferably in a range from 0.05 wt.% to 3.0 wt.%, most preferably in a range from 0.10 wt.% to 2.0 wt.% by weight of the agglomerate; optionally, a second amount of Al in a range from 0.01 wt.% to 5.0 wt.%, preferably in a range from 0.02 wt.% to 4.0 wt.%, more preferably in a range from 0.05 wt.% to 3.0 wt.%, most preferably in a range from 0.10 wt.% to 2.0 wt.% by weight of the agglomerate;

optionally, a second amount of Mg in a range from 0.01 wt.% to 5.0 wt.%, preferably in a range from 0.02 wt.% to 4.0 wt.%, more preferably in a range from 0.05 wt.% to 3.0 wt.%, most preferably in a range from 0.10 wt.% to 2.0 wt.% by weight of the agglomerate;

optionally, second amounts of P and/or S in a range from 0.05 wt.% to 3.0 wt.%, preferably in a range from 0.10 wt.% to 3.0 wt.%, more preferably in a range from 0.15 wt.% to 1 .0 wt.%, most preferably in a range from 0.20 wt.% to 0.50 wt.% by weight of the agglomerate;

optionally, a second amount of Ti in a range from 0.05 wt.% to 3.0 wt.%, preferably in a range from 0.10 wt.% to 3.0 wt.%, more preferably in a range from 0.15 wt.% to 1 .0 wt.%, most preferably in a range from 0.20 wt.% to 0.50 wt.% by weight of the agglomerate;

optionally, second amounts of Ni, Cu, Cr, Ba, Zr, Sr, Mo, Hf and/or Co in a range from 0.001 wt.% to 1 .0 wt.%, preferably in a range from 0.005 wt.% to 0.5 wt.%, more preferably in a range from 0.01 wt.% to 0.1 wt.%, most preferably in a range from 0.02 wt.% to 0.05 wt.% by weight of the agglomerate; and

optionally, second amounts of Li, As, Sb, Hg, Br and/or Cl in a range from 250 ppm to 0.1 ppm, preferably in a range from 100 ppm to 0.2 ppm, more preferably in a range from 50 ppm to 0.5 ppm, most preferably in a range from 30 ppm to 1 ppm by weight of the agglomerate; and

balance oxygen, water and unavoidable impurities.

wherein the second amount of Zn is less than the first amount of Zn;

optionally, wherein the second amount of Pb is less than the first amount of Pb;

optionally, wherein the second amount of Na is less than the first amount of Na;

optionally, wherein the second amount of K is less than the first amount of K;

optionally, wherein the second amount of Cd is less than the first amount of Cd; and optionally, wherein the second amount of Cl is less than the first amount of Cl.

Method of iron-making and/or steel-making

The second aspect provides a method of iron-making and/or steel-making, comprising:

preparing a charge comprising coke, iron ore, limestone, an agglomerate, for example a pellet or a briquette, and optionally sinter; and

heating the charge to make iron or steel and thereby discharging particles including a ferrous material and/or a carbon material;

wherein the method comprises providing the agglomerate according to the first aspect.

In one example, the method comprises:

collecting, optionally electrostatically, the discharged particles; wherein providing the agglomerate comprises using, at least in part, the collected particles discharged from heating a previous charge.

In this way, the discharged particles may be recycled, thereby recovering Fe therefrom, while undesirable elements may be reduced or removed therefrom. Other methods of collecting are known.

In one example, the treating the agglomerate is performed, at least in part, before preparing the charge. In this way, undesirable elements may be reduced or removed from the agglomerate before the iron-making and/or steel-making. In this way, these undesirable elements are not included in the charge.

In one example, the treating the agglomerate is performed, at least in part, during heating the charge. In this way, undesirable elements may be reduced or removed from the agglomerate during the iron-making and/or steel-making.

In one example, the preparing the charge comprises including the agglomerate therein in a range from 0.5 wt.% to 6.0 wt.%, preferably in a range from 1 .0 wt.% to 5.0 wt.%, more preferably in a range from 1 .5 wt.% to 4.0 wt.%, most preferably in a range from 2.0 wt.% to 3.0 wt.% by weight of the charge.

In this way, a relatively large proportion of Fe may be recovered, for example from the collected particles discharged from the iron-making and/or steel-making.

Agglomerate

The third aspect provides an agglomerate, for example a pellet or a briquette, for use in ironmaking and/or steel-making, having a first composition comprising:

Fe in a range from 20 wt.% to 80 wt.%, preferably in a range from 30 wt.% to 70 wt.%, more preferably in a range from 35 wt.% to 65 wt.% by weight of the agglomerate;

C in a range from 12.5 wt.% to 40 wt.%, preferably in a range from 14 wt.% to 25 wt.%, more preferably in a range from 15 wt.% to 20 wt.% by weight of the agglomerate; and

a first amount of Zn in a range from 0.10 wt.% to 10.0 wt.%, preferably in a range from 0.29 wt.% to 7.0 wt.%, more preferably in a range from 0.30 wt.% to 4 wt.%, most preferably in a range from 0.35 wt.% to 2.0 wt.% by weight of the agglomerate.

The agglomerate may be as described with respect to the first aspect. It should be understood that the agglomerate is before treating, as described with respect to the first aspect. By treating the agglomerate as described with respect to the first aspect, at least the first amount of Zn may be reduced or removed therefrom, thereby recovering the Fe therein for use in iron-making and/or steel-making.

Definitions

Throughout this specification, the term “comprising” or “comprises” means including the component(s) specified but not to the exclusion of the presence of other components. The term“consisting essentially of or“consists essentially of” means including the components specified but excluding other components except for materials present as impurities, unavoidable materials present as a result of processes used to provide the components, and components added for a purpose other than achieving the technical effect of the invention, such as colourants, and the like.

The term “consisting of” or “consists of means including the components specified but excluding other components.

Whenever appropriate, depending upon the context, the use of the term “comprises” or “comprising” may also be taken to include the meaning“consists essentially of” or“consisting essentially of, and also may also be taken to include the meaning“consists of or“consisting of.

The optional features set out herein may be used either individually or in combination with each other where appropriate and particularly in the combinations as set out in the accompanying claims. The optional features for each aspect or exemplary embodiment of the invention, as set out herein are also applicable to all other aspects or exemplary embodiments of the invention, where appropriate. In other words, the skilled person reading this specification should consider the optional features for each aspect or exemplary embodiment of the invention as interchangeable and combinable between different aspects and exemplary embodiments.

Brief description of the drawings

For a better understanding of the invention, and to show how exemplary embodiments of the same may be brought into effect, reference will be made, by way of example only, to the accompanying diagrammatic Figures, in which:

Figures 1A and 1 B schematically depict typical particle size distributions of particles included in a mixture for a method of providing an agglomerate according to an exemplary embodiment; Figures 2A and 2B schematically depict structures of PVA for a binder for a method of providing an agglomerate according to an exemplary embodiment; Figure 3 schematically depicts pyrolysis of PVA during treating an agglomerate according to an exemplary embodiment;

Figure 4 schematically depicts a graph of pressure differential against temperature during treating an agglomerate according to an exemplary embodiment;

Figure 5 schematically depicts a method of providing an agglomerate according to an exemplary embodiment;

Figure 6 schematically depicts a method of iron-making and/or steel-making according to an exemplary embodiment; and

Figure 7 shows a graph of normalised concentrations of C, Zn and Pb for treating an agglomerate at a first temperature of 1200 °C as a function of a first duration from 0 minutes (i.e. raw, before treating) to 90 minutes.

Detailed Description of the Drawings

Method of providing an agglomerate Agglomerates according to exemplary embodiments (Tables 3 to 7) and comparative examples (Table 2) were prepared, as described below. The comparative examples differed from the exemplary embodiments primarily by the C contents of the agglomerates before treating. Mixtures were prepared by binding particles including ferrous material and carbon material using a binder, as described above.

The particles were obtained from different waste products, including black sand (P1), ladle arc dust (P2), secondary vent dust (P3), desulphur dust (P4), precipitation dust from sinter plant ESP (P5), iron oxide dust (P6), blast furnace filter cake (P7), killed BOS filter cake (P8) and/or lagoon material (P9). Generally, P2 to P6 may be known as works arising dust. Generally, killed BOS filter cake (P8) is provided by killing BOS filter cake with black sand (P1) and/or works arising dust (P2 to P6). Generally, lagoon material (P9) comprises a slurry mix of BOS filter cake and blast furnace filter cake (P7). Typical compositions of samples P1 to P9 of the particles are shown in Table 1 . The particles from the different waste products were blended to achieve target Fe and C contents, particularly P7 to P9. A typical blend is 45 wt.% P7 + 37.5% P8 + 17.5% P9, giving a C content in a range from 15 wt.% to 20 wt.%.

Table 1 : Typical compositions of samples P1 to P8 of the particles.

The particles included 2 wt.% olivine (i.e. (Mg,Fe) ₂ SiC> ₄ ), as a flux. Figures 1A and 1 B schematically depict typical particle size distributions of particles included in a mixture for a method of providing an agglomerate according to an exemplary embodiment.

Particularly, Figure 1A shows a graph of a <1 .0 mm (nominal) particle size distribution of the particles included in the mixture, obtained after screening the particles to this size fraction. The particle size distribution was measured by laser diffraction. This fraction represented 67 wt.% of the particles included in the mixture with the balance (i.e. 33 wt.%) in a size range from 1 .0 mm to 5.0 mm. The sub-millimetre size fraction is important in the reduction of the outer shell of the agglomerate, which results in the forming of a sintered hardened shell and therewith in an increased compressive strength of the agglomerate. Particularly, Figure 1 B shows a graph of a <0.5 mm (nominal) particle size distribution of the particles included in the mixture without flux. The particle size distribution was measured by laser diffraction. The multimodal distribution is due to the diversity of types of particles.

For some examples, the binder comprised an aqueous solution of polyvinyl alcohol, PVA. The aqueous solution of the PVA was made by heating water to near boiling temperature, adding the PVA and preparing the aqueous solution of PVA comprising PVA in an amount of about 10 wt.%. In this way, the mixtures before forming contained dry PVA in an amount of about 0.5 wt.% of the total weight of the agglomerate.

For other examples, the binder comprised Portland cement, included at about 10 wt.% to 12. wt.% (dry) of the total weight of the agglomerate.

Figure 2 schematically depicts a structure of PVA for a binder for a method of providing an agglomerate according to an exemplary embodiment.

The PVA used for this method is commercially available in powder form and covers all suitable grades that would be considered as being in the medium viscosity range and which are soluble in water. The PVA chain may be in various degrees of saturation with OH groups but typically saturation levels from 80% to fully hydrolysed are employed.

The mixed particles were mixed the binder to provide the mixture. The mixture was formed into briquettes (i.e. agglomerate precursors), having dimensions of about 35 mm by 20 mm by 15 mm, using a roll press. A moisture content of the agglomerate precursors before curing was in about 10 wt.% to 1 1 wt.% by weight of the agglomerate precursors.

The agglomerate precursors were cured at a second temperature of about 100 °C for a second duration of about 3 hours, thereby providing the agglomerates. A moisture content of the agglomerates after the curing and before the treating was in a range from 1 wt.% to 4 wt.% by weight of the agglomerates.

The agglomerates were treated by heating in a presence of oxygen at a first temperature in a range from 1 100 °C to 1400 °C for a first duration in a range from 20 minutes to 1 hour, as described further with respect to Tables 2 to 7.

Figure 3 schematically depicts pyrolysis of PVA during treating an agglomerate according to an exemplary embodiment. The second stage takes place during heating of the agglomerate to the first temperature, particularly, as the temperature is elevated to and above a decomposition temperature of the PVA (about 200 °C). As the temperature increases further between 200 °C and 450 °C, OH- groups are stripped from the PVA polymer chain length, producing polyenes. Free radical reactions may then take place. Without wishing to be bound by any theory, it is thought that multi-valent metal ions present in the ferrous material act as catalysts in chain-scission and aromatic compound formation, producing oligomers present as char products. It is also thought that elemental carbon present in the agglomerate also takes part to a greater or lesser degree in complex organic chemistry making up the formation of the oligomer char products. The oligomer char products then form a thermally stable binding structure that is stable up to about 880 °C to 900 °C, when this binding structure breaks down and the carbon is burnt out.

Figure 4 schematically depicts a graph of pressure differential against temperature for an agglomerate according to an exemplary embodiment.

The oligomer char products form the thermally stable binding structure that is stable up to about 880 °C to 900 °C, when this binding structure breaks down and the carbon is burnt out.

The point at which the second stage binding mechanism fails can be seen by simulating a blast furnace reduction process by placing the agglomerate into a retort and passing a reducing gas over the agglomerate at the same time that the retort is heated in a furnace. The gas is passed through a filter where the pressure differential is measured. The point at which the binding mechanism fails can be clearly seen by the change in pressure at about 880 °C to 900 °C as a small degree of degradation takes place.

Results

Comparative example CE1 - CE4 were prepared, as described above, using the PVA binder, comprising C in a range less than 12.5 wt.%. Examples E1 - E2 were prepared, as described above, using the PVA binder. Examples E3 - E5 were prepared, as described above, using the Portland cement binder. Treating the agglomerates was by heating the agglomerates in a muffle furnace (i.e. in a presence of oxygen) at various first temperatures in a range from 1 100 °C to 1400 °C for various first durations in a range from 20 minutes to 1 hour.

Four comparative examples CE1 to CE4 of agglomerates were provided. Compositions of the comparative examples before treating and after treating are shown in Table 1 , together with temperatures and durations of treating. A suffix‘b’ denotes the comparative example before treating (i.e. CEI b to CE4b) and a suffix‘a’ denotes the respective comparative example after treating (i.e. CE1 a to CE4a).

Table 2: Compositions of agglomerates of comparative examples before and after treating. Comparative examples CE1 b to CE3b before treating have relatively low C contents (1 .81 wt.%, 3.88 wt.% and 4.66 wt.%, respectively) and relatively low Zn and Pb contents. However, reductions in Zn contents are relatively small after treating, such that Zn contents of comparative examples CE1 a to CE3a after treating remain significant (at least 0.18 wt.%), hence unsuitable for use in iron-making and/or steel-making. Comparative example CE4b before treating has a C content of 9.21 wt.% but a relatively low Zn content of 0.28 wt.% and a relatively low Pb content of 0.15 wt.%. While Zn and Pb are removed by treating at 1 100 °C for 60 minutes (CE4b), the initial amounts of Zn and Pb are relatively low. Furthermore, Na and K (as Na2<D and K2O respectively) are not removed. Example 1

An agglomerate E1 according to an exemplary embodiment was subject to 3 different heat treatments. Compositions of the examples before treating (E1 b) and after treating (E1 a.1 to E1 a.3) are shown in Table 3, together with temperatures and durations of treating. A suffix‘b’ denotes the example before treating (i.e. E1 b) and a suffix‘a’ denotes the respective example after treating (i.e. E1 a.1 to E1 a.3).

Table 3: Compositions of agglomerates E1 according to exemplary embodiments before and after treating.

A C content of the example agglomerate before treating (E1 b) was 20.2 wt.%. Treating of this agglomerate, having a relatively high C content, at 1200 °C is effective in substantially removing even a relatively high Zn content, from 0.87 wt.% to just 0.02 wt.%. Furthermore, a relatively high Pb content is also removed, to below a limit of detection, within 20 minutes at 1200 °C. In addition, Na and particularly K are also reduced significantly. The C content is almost entirely consumed after a duration of 1 hour at 1200 °C and the agglomerate exhibited through metallisation of Fe after treating. Example 2

An agglomerate E2 according to an exemplary embodiment was subject to 1 heat treatment. Compositions of the examples before treating (E2b) and after treating (E2a) are shown in Table 4, together with temperature and duration of treating. A suffix‘b’ denotes the example before treating (i.e. E2b) and a suffix‘a’ denotes the respective example after treating (i.e. E2a).

Table 4: Compositions of agglomerates E2 according to exemplary embodiments before and after treating. A C content of the example agglomerate before treating (E2b) was 19.82 wt.%. Treating of this agglomerate, having a relatively high C content, at 1200 °C is effective in substantially removing even a relatively high Zn content, from 0.92 wt.% to <0.05 wt.%. Furthermore, a relatively high Pb content is also removed, to below a limit of detection. In addition, K is also reduced significantly. In addition, Cd is also removed, from 57 ppm to <5 ppm. Further, Cl is also removed. The C content is almost entirely consumed after a duration of 1 hour at 1200 °C and the agglomerate after treating exhibited through metallisation of Fe.

Example 3 An agglomerate E3 according to an exemplary embodiment was subject to 3 different heat treatments. Compositions of the examples before treating (E3b) and after treating (E3a.1 to E3a.3) are shown in Table 5, together with temperatures and durations of treating. A suffix‘b’ denotes the example before treating (i.e. E3b) and a suffix‘a’ denotes the respective example after treating (i.e. E3a.1 to E3a.3).

Table 5: Compositions of agglomerates E3 according to exemplary embodiments before and after treating.

A C content of the example agglomerate before treating (E3b) was 16.1 wt.%. Treating of this agglomerate, having a relatively high C content, at 1200 °C is effective in substantially removing even a relatively high Zn content, from 0.9 wt.% to <0.05 wt.% after just 20 minutes. The apparently anomalous Zn content after 1 hour is due to recondensation of the Zn onto outer surfaces of the example agglomerate during cooling. Furthermore, a relatively high Pb content is also removed, to below a limit of detection. In addition, Na and K are also reduced significantly. Further, Cl is also removed. The C content is almost entirely consumed after a duration of 1 hour at 1200 °C and the agglomerate after treating exhibited through metallisation of Fe.

Example 4 An agglomerate E4 according to an exemplary embodiment was subject to 3 different heat treatments. Compositions of the examples before treating (E4b) and after treating (E4a.1 to E4a.3) are shown in Table 6, together with temperatures and durations of treating. A suffix‘b’ denotes the example before treating (i.e. E4b) and a suffix‘a’ denotes the respective example after treating (i.e. E4a.1 to E4a.3).

Table 6: Compositions of agglomerates E4 according to exemplary embodiments before and after treating.

A C content of the example agglomerate before treating (E4b) was 16.1 wt.%. Treating of this agglomerate, having a relatively high C content, at 1200 °C is effective in substantially removing even a relatively high Zn content, from 1 .0 wt.% to 0.05 wt.%. Furthermore, a relatively high Pb content is also removed, to below a limit of detection. In addition, Na and K are also reduced significantly. Further, Cl is also removed. The C content is almost entirely consumed after a duration of 1 hour at 1200 °C and the agglomerate after treating exhibited through metallisation of Fe. Example 5

An agglomerate E5 according to an exemplary embodiment was subject to 3 different heat treatments. Compositions of the examples before treating (E5b) and after treating (E5a.1 to E5a.3) are shown in Table 7, together with temperatures and durations of treating. A suffix‘b’ denotes the example before treating (i.e. E5b) and a suffix‘a’ denotes the respective example after treating (i.e. E5a.1 to E5a.3).

Table 7: Compositions of agglomerates E5 according to exemplary embodiments before and after treating.

A C content of the example agglomerate before treating (E5b) was 12.5 wt.%. Treating of this agglomerate, having a relatively high C content, at 1200 °C is effective in substantially removing even a relatively high Zn content, from 0.8 wt.% to 0.20 wt.%. Furthermore, a relatively high Pb content is also removed, to below a limit of detection. In addition, Na and K are also reduced significantly. Further, Cl is also removed. The C content is almost entirely consumed after a duration of 1 hour at 1200 °C and the agglomerate after treating exhibited through metallisation of Fe. Analytical methods

Moisture content

Moisture content MC is determined by drying a nominally 100 g sample at 1 10°C for a minimum of 4 hours, preferably overnight.

W1 - W2

MC = X 100 %

Wl where Wl is a mass of the sample before drying and W2 is a mass of the sample after drying.

1 . Using the balance place a suitable container onto the pan and record the weight of the container (TARE weight).

2. Zero the balance, and depending on the material type, weigh out approximately 100g of the test material and note the weight (i.e. Wl).

3. Transfer the dish and contents to the drying oven (1 10°C) and leave for a minimum period of 4 hours, or preferably overnight.

4. Remove the dish and contents from the oven, cool and re-weigh. Subtract the initial weight of the container (TARE weight) to obtain the corrected weight (i.e. W 2).

5. Express weight loss as a percentage of original weight.

Loss on ignition

Loss on ignition LOI is determined by igniting a nominally 1 g sample at 1000°C for a 1 hour, using a platinum crucible.

(W2 - W 3)

LOI = X 100 %

(W2 - Wl) where Wl is a mass of the crucible, W 2 is a mass of the crucible + sample before ignition and W 3 is a mass of the crucible + sample after ignition.

1 . Ignite an empty crucible in a muffle furnace at 1000°C for 10 min.

2. Remove crucible from the furnace and allow to cool in a desiccator. 3. Remove the crucible from the desiccator with forceps and carefully brush the underneath prior to placing in the balance.

4 Weigh the crucible to four decimal places (i.e. W 1).

5 Add approximately 1g of sample to the crucible and reweigh (i.e. W 2).

6. Place the crucible in the furnce and ignite at 1000°C for 1 hour.

7. Remove the crucible from the furnace and allow to cool in a desiccator.

8. Remove the crucible from the desiccator with forceps and carefully brush the underneath prior to placing in the balance.

9. Weigh the crucible (i.e. W2>).

Metals, non-metals and oxides thereof

Metals, non-metals and oxides thereof are gerenally determined by X-ray fluorescence (XRF), for example using a Bruker S8 X-ray spectrometer according to the manufacturer’s instructions, using a sample having a mass of about 0.7 g, against calibration standards. C, S and Cl are determined by alternative analytical methods, as described below.

Table 8: Calibration standards for oxide determination by XRF.

Table 9: Determinable ranges of elements and compounds by XRF. Carbon and sulphur

Carbon and sulphur are determined by infrared absorption, for example using a Leco CS-444, according to the manufacturer’s instructions, using a sample having a mass of about 0.2 g, against calibration standards.

The Leco CS-444 Carbon Sulphur system is a microprocessor based software driven instrument for wide range measurement of carbon and sulphur content of metals, ores, ceramics and other inorganic materials. The CS-444 uses the HF-400 induction furnace and measures carbon and sulphur by infrared absorption.

Analysis begins by weighing out a sample into a ceramic crucible on the built in balance. Accelerator material is added, the crucible is placed on the loading pedestal and the analyse key is pressed. Furnace closure is performed automatically, then the combustion chamber is purged with oxygen to drive off atmospheric gasses. After purging, oxygen flow through the system is restored and the induction furnace is turned on. The inductive elements of the sample and accelerator couple with the high frequency field of the furnace. The pure oxygen environment and the heat generated by this coupling cause the sample to combust. During combustion all elements reduced, releasing the carbon, which immediately binds with the oxygen to form CO or CO2. Also sulphur bearing elements are reduced releasing sulphur, which binds with oxygen to form SO2. Sample gases are swept into the carrier stream. Sulphur is measured as sulphur dioxide in the first IR cell. Carbon monoxide is converted to carbon dioxide in the catalytic heater assembly while sulphur trioxide is removed from the system in a cellulose filter trap. Carbon is measured as carbon dioxide in the IR cells, while gasses flow through both the low and high range cells. The measurement will be made only on the range selected. The low carbon range features a greater resolution carbon content as a result of the longer path length in the IR cell. In contrast, when high range carbon is selected, sample gasses flow through an IR cell with a shorter path length. The high carbon range provides a better resolution of high carbon content. The difference in path length assures optimum representation of the gasses for the range selected.

Table 10: Calibration standards for carbon and sulphur determination by infrared absorption.

Chloride and bromide Chloride is determined by photometric analysis, for example using a Thermo Gallery Automated Photometric Analyzer according to the manufacturer’s instructions, using a sample having a mass of about 4.0 g, against calibration standards.

1. Transfer 4.0000 ± 0.0001 g of sample to a 400 ml squat beaker.

2. Add approximately 150 ml of deionised water.

3. Place a stirring rod in the beaker and cover with a watch glass.

4. Bring the solution to the boil and digest at just below boiling point with occasional stirring for 1 hour. Allow to cool. 5. Filter the solution through a paper pulp pad into a 200 ml volumetric flask, in a chlorine-free atmosphere.

6. Rinse the beaker and pad with deionised water.

7. Dilute the solution to the 200 ml mark of the flask with deionised water and mix well.

8. Pour sample into vials and place on the Thermo Gallery instrument for analysis.

Additionally and/or alternatively, Cl and/or Br at least may be determined by ion chromatography (IC), for example according to ASTM D4327 - 17 (Standard Test Method for Anions in Water by Suppressed Ion Chromatography). Ion chromatography provides for both qualitative and quantitative determination of seven common anions, F , Cl , NO2 , HPO4 ² , Br, NO3 , and SO4 ² , in the milligram per litre range from a single analytical operation requiring only a few millilitres of sample and taking approximately 10 to 15 minutes for completion. Additional anions, such as carboxylic acids, can also be quantified.

ICP-OES

Additionally and/or alternatively, aluminum (Al), cadmium (Cd), calcium (Ca), chromium (Cr), cobalt (Co), copper (Cu), iron (Fe), lead (Pb), magnesium (Mg), manganese (Mn), molybdenum (Mo), nickel (Ni), potassium (K), sodium (Na), strontium (Sr), tin (Sn), titanium (Ti), vanadium (V), zinc (Zn), and zirconium (Zr) may be determined by inductively coupled plasma optical emission spectroscopy (ICP-OES), for example according to UOP714 - 07 (Metals in Miscellaneous Samples by ICP-OES).

Particle size distribution

The particle size distribution is measured by use of light scattering measurement of the particles in an apparatus such as a Malvern Mastersizer 3000, arranged to measure particle sizes from 10 nm to 3500 micrometres, with the particles dry-dispersed or wet-dispersed in a suitable carrier liquid (along with a suitable dispersant compatible with the particle surface chemistry and the chemical nature of the liquid) in accordance with the equipment manufacturer’s instructions and assuming that the particles are of uniform density. Particularly, the particle size distribution is measured according to ASTM B822 - 02 or ASTM B822 - 17 (Standard Test Method for Particle Size Distribution of Metal Powders and Related Compounds by Light Scattering).

Additionally and/or alternatively, the particle size distribution is measured by sieving according to ASTM E276 - 13 (Standard Test Method for Particle Size or Screen Analysis at No. 4 (4.75- mm) Sieve and Finer for Metal-Bearing Ores and Related Materials). Additionally and/or alternatively, the particle size distribution for relatively coarser particles is measured by sieving according ASTM E389 - 13 (Standard Test Method for Particle Size or Screen Analysis at No. 4 (4.75-mm) Sieve and Coarser for Metal-Bearing Ores and Related Materials).

Method

Figure 5 schematically depicts a method of providing an agglomerate, for example a pellet or a briquette, for use in iron-making and/or steel-making, according to an exemplary embodiment.

At S501 , a mixture is provided by binding particles, including a ferrous material and a carbon material, using a binder.

The binder preferably comprises an aqueous solution of polyvinyl alcohol, PVA.

At S502, the mixture is formed, thereby providing an agglomerate precursor.

At S503, the agglomerate precursor is cured, thereby providing the agglomerate.

The agglomerate before treating has a first composition comprising:

Fe in a range from 20 wt.% to 80 wt.%, preferably in a range from 30 wt.% to 70 wt.%, more preferably in a range from 35 wt.% to 65 wt.% by weight of the agglomerate;

C in a range from 12.5 wt.% to 40 wt.%, preferably in a range from 14 wt.% to 25 wt.%, more preferably in a range from 15 wt.% to 20 wt.% by weight of the agglomerate; and

a first amount of Zn in a range from 0.10 wt.% to 10.0 wt.%, preferably in a range from 0.29 wt.% to 7.0 wt.%, more preferably in a range from 0.30 wt.% to 4.0 wt.%, most preferably in a range from 0.35 wt.% to 2.0 wt.% by weight of the agglomerate;

At S504, the agglomerate is treated.

The treating the agglomerate comprises heating the agglomerate in a presence of oxygen at a first temperature in a range from 1050 °C to 1400 °C, preferably from 1 100 °C to 1300 °C, more preferably from 1 150 °C to 1250 °C for a first duration in a range from 0.25 hours to 12 hours, preferably in a range from 0.5 hours to 3 hours, more preferably in a range from 0.75 hours to 1 .5 hours

The agglomerate after treating has a second composition comprising:

Fe in a range from 30 wt.% to 90 wt.%, preferably in a range from 35 wt.% to 85 wt.%, more preferably in a range from 40 wt.% to 80 wt.% by weight of the agglomerate;

C in a range from 0.0 wt.% to 9 wt.%, preferably in a range from 0.01 wt.% to 5 wt.%, more preferably in a range from 0.1 wt.% to 1 wt.% by weight of the agglomerate; and a second amount of Zn in a range from 0.0 wt.% to 1 .0 wt.%, preferably in a range from 0.001 wt.% to 0.5 wt.%, more preferably in a range from 0.01 wt.% to 0.1 wt.% by weight of the agglomerate.

The second amount of Zn is less than the first amount of Zn.

The method may comprise any of the steps described herein.

Figure 6 schematically depicts a method of iron-making and/or steel-making according to an exemplary embodiment.

At S601 , a charge is prepared, comprising coke, iron ore, limestone, an agglomerate, for example a pellet or a briquette, and optionally sinter.

At S602, the charge is heated to make iron or steel and thereby discharging particles including a ferrous material and/or a carbon material.

The method comprises providing the agglomerate according to the first aspect, as described with respect to Figure 5.

The method may comprise any of the steps described herein.

Example E6

Figure 7 shows a graph of normalised concentrations of C, Zn and Pb for treating an agglomerate at a first temperature of 1200 °C as a function of a first duration from 0 minutes (i.e. raw, before treating) to 90 minutes. Table 1 1 shows compositions of the agglomerates E6 before and after treating.

In this example, the C content before treating is 8.10 wt.%. The Pb and Zn contents decrease during treating, reaching approximately constant minima at about 30 minutes, coincident with depletion of the C. Increasing the C content to the ranges described herein reduces the minima for Pb and Zn, as described above, since the increased C content provides for further removal of Pb and Zn, amongst other elements, before depletion of the C. Increasing the first temperature is expected to accelerate removal of Pb and Zn, amongst other elements.

Table 1 1 : Compositions of agglomerates E6 before and after treating. Raw is before treating.

Although a preferred embodiment has been shown and described, it will be appreciated by those skilled in the art that various changes and modifications might be made without departing from the scope of the invention, as defined in the appended claims and as described above.

In summary, the invention provides a method of providing an agglomerate, for example a pellet or a briquette, for use in iron-making and/or steel-making. A method of providing an agglomerate, for example a pellet or a briquette, for use in iron-making and/or steel-making, is described. A mixture is provided by binding particles, including a ferrous material and a carbon material, using a binder, preferably comprising an aqueous solution of polyvinyl alcohol, PVA, and formed, thereby providing an agglomerate precursor. The agglomerate precursor is cured, thereby providing the agglomerate, which is treated by heating the agglomerate in a presence of oxygen at a first temperature in a range from 1050 °C to 1400 °C for a first duration in a range from 0.25 hours to 12 hours. The agglomerate before treating has a first composition comprising: Fe in a range from 20 wt.% to 80 wt.%; C in a range from 12.5 wt.% to 40 wt.%; and a first amount of Zn in a range from 0.10 wt.% to 10.0 wt.%, by weight of the agglomerate. The agglomerate after treating has a second composition comprising: Fe in a range from 30 wt.% to 90 wt.%; C in a range from 0.0 wt.% to 9 wt.%; and a second amount of Zn in a range from 0.0 wt.% to 1 .0 wt.%, by weight of the agglomerate. The second amount of Zn is less than the first amount of Zn. In this way, Fe may be recovered from recycled waste materials, for example, while undesirable elements, for example Zn, are removed. A relatively high C content of the agglomerate, before treating, provides (e.g. CO) and/or is (i.e. C) a reducing agent, thereby at least partially reducing compounds of metals and/or non-metals to elemental forms, even in the presence of oxygen. Hence, Fe and Zn are at least partially reduced by and/or due to the C during the treating of the agglomerate, for example from oxides thereof to respective metals. The metallic Fe is retained in the treated agglomerate while the metallic Zn volatilises therefrom during the treating. Particularly, the relatively high C content of the agglomerate before treating provides for both at least partial reduction of compounds of the undesirable elements, at their respective amounts, and for at least partial reduction of oxides of Fe. Furthermore, the relatively high C content of the agglomerate, before treating, may provide (e.g. CO) and/or be (i.e. C) a reducing agent for compounds of other undesirable elements, which may also be at least partially removed from the agglomerate similarly during the treating. In this way, an efficiency of iron-making and/or steel-making is increased, as described below, while impurities in the iron or steel due to the undesirable elements are decreased. The invention also provides a method of iron-making and/or steel-making using such an agglomerate and such an agglomerate.

Attention is directed to all papers and documents which are filed concurrently with or previous to this specification in connection with this application and which are open to public inspection with this specification, and the contents of all such papers and documents are incorporated herein by reference.

All of the features disclosed in this specification (including any accompanying claims and drawings), and/or all of the steps of any method or process so disclosed, may be combined in any combination, except combinations where at most some of such features and/or steps are mutually exclusive.

Each feature disclosed in this specification (including any accompanying claims, and drawings) may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise. Thus, unless expressly stated otherwise, each feature disclosed is one example only of a generic series of equivalent or similar features.

The invention is not restricted to the details of the foregoing embodiment(s). The invention extends to any novel one, or any novel combination, of the features disclosed in this specification (including any accompanying claims and drawings), or to any novel one, or any novel combination, of the steps of any method or process so disclosed.