CURRENT STATE OF THE METALLURGIC PROCESSES

Hydrometallurgical processes for the treatment of ores, concentrates and materials involve various relevant operations, such as: leaching or dissolution of the metal of interest, performed in piles and reactors, the concentration and purification of the solutions by solvent extraction and ion exchange; and finally, the synthesis of metal or metal compound desired by the use of precipitation, crystallization or electrowinning.

Industrial processes commonly use a suitable environment for dissolution and support themselves in conditions that are favorable for the leaching process, concerning: gases, temperature, microorganisms, mechanical processes, etc. These processes are used in the copper case and other metals, with the oxidant agent being ferric sulfate.

Generally, metals of interest in the solution are in presence of other species. Some of these species contain ions that support the hydrometallurgical process in order to achieve electrowinning. However, in most cases, these species contain ions that inhibit or do not allow the electrowinning to occur in a proper way.

Leaching processes in the mining industry occur at higher rates than they do in nature, but high investments and operational costs (energy, abrasives, corrosive solutions, etc.) are needed in order to maintain the operations.

The patents that support these statements are the following: CESL, UBC, HPAL- Angloamerican, Dynatec, etc. (United States Patents N° 5,730,776; N° 6,503,293; N° 6,755,891 ; N° 7,125,436).

Other known hydrometallurgical processes include bio-leaching that use microorganisms, which are autogenous in the use of reagents such as sulfuric acid and ferric sulfate for sulfur ores. However, these processes require large scale equipments and installations and high stocks of materials and solutions in the industrial circuits in order to avoid the high residency times of the slow leaching velocity that is produced in weak solutions with help of the oxidizing bacteria from the iron and sulfur compounds present in the minerals.

The references that support these statements are the following: United States Patent N° 7,160,354; Batty & Rorke" Development and Commercial Demonstration of the BioCOP™ Thermophile Process"). The processes of mineral dissolution that use ferric ion as a oxidizing agent are Galvanox, Albion and Brenda, which use pyrite, oxygen and/or chloride gas to periodically regenerate the oxidizing agent. The main disadvantages of these processes are the high consumption of compressed air, the high consumption of sulfuric acid and the high expenses that represent the use of chloride gas. The Brenda process commonly used to clean molybdenum concentrates, also requires closed installations and equipment and also materials resistant to this highly corrosive chlorinated environment (Cl ₂ -FeCl ₃ -H ₂ S0 ₄ ).

The patents and publications that support these statements are the following: United States Patents N° 3,674,424; 4,1 15,221 ; 5,993,635; 6,833,021 ; Chilean patent N° 33,924; Habashi (1993); Gupta (1992); IMOA (2008); Sutulov (1980) and Lundstrom et al., (2005); Dixon and Tshilombo (2005); Dixon et al., (2007).

In the copper case, as an illustration and without loss of generality, in Figure 1 , the main hydrometallurgical operations used in conventional processes for the processing of sulfur copper minerals are illustrated in general terms.

The legends of Figure 1 correspond to:

a. Main Operations: A- Leaching or Bioleaching in Piles and/or Dumps, B- Solvent Extraction and C- Electrowinning.

b. Main Currents or Flows: 1- Sulfur Mineral, 2- PLS Solution, 3- Discarded Material, 4- Raffinate Solution, 5- Rich Electrolyte, 6- Copper Cathodes and 7- Weak Electrolyte.

Flow 1 of Figure 1 , contains Sulfur Minerals which are fed to Sub Process A in Figure 1. Sub Process A consists in Leaching or Bioleaching in Piles and/or Dumps.

From the Leaching produced in Sub Process A, as an example and without loss of generality, a solution containing copper sulfate (CuS0 ₄ ) is obtained at a concentration of 1-10 g/L, which in the industry is known as PLS (Pregnant Leach Solution) and is represented by Flow 2 in Figure 1.

Flow 3 corresponds to Discarded Material of the Leaching process; this material is transported to Dumps where a second process of Leaching could be attempted.

Flow 2 in Figure 1 is fed to the Solvent Extraction plant that is indicated as Sub Process B in Figure 1. At this stage the solution that comes from the Leaching Piles is liberated from its impurities and its copper content is concentrated, passing from 1-10 g/L to 40-50 g/L, by using extracting agents. In order to extract the copper from the PLS solution, this is mixed with an organic solution (mixture of extractant and high flashpoint paraffin; 10-20%vol). The extracting agent captures the copper ions (Cu ²⁺ ) in a selectively and generates a weak copper solution (Cu < 0.5 g/L) which is known as Raffinate Solution (Flow 4), which is conditioned and recycled to the Leaching process. Later, using an acid Weak Electrolyte solution (Flow 7) the copper is released from the extractant, generating Flow 5 which is the Rich Electrolyte.

The Rich Electrolyte (Flow 5) with 40-50 g/L Cu is processed by conventional Electrowinning (Sub Process C) to obtain the main product which is Copper Cathodes of high purity (99,99% Cu) (Flow 6). A solution defined as Weak Electrolyte (Flow 7) is generated as a sub product; it will be recycled to the Solvent Extraction Sub Process B for its copper re-concentration.

As a summary, it its mentioned that the Leaching process of minerals and/or concentrates have the inconvenience that the regeneration of the oxidizing agent is complex in terms of investment and the additional operating equipment needed; also expensive because it is necessary to regenerate or constantly supply the oxidizing agent and even adding sulfuric acid in some cases.

On the other hand, the conventional Electrowinning process presents some disadvantages: Low mass transfer rate because of the low agitation applied in industrial cells, low specific surface of the flat cathodes 1 m x 1 m that are used and high consumption of electric energy (1.8-2.6 kWh/Cu kg), promoted by the formation of acid mist when the water is decomposed over the anode.

SUMMARY OF THE INVENTION

According to the present invention, there is provided a metallurgical method for operating an autogenous production circuit for producing metal(s), said method using one or more oxidizing agents generated electrolytically in a cell with one or more interfaces which allows anion exchange, said method comprising steps of:

(a) leaching of mineral(s) or material(s) containing at least one metal of interest (LX) in a first cell to produce a pregnant leach solution and an acid-ferrous aqueous solution;

(b) using solvent extraction process(es) or selection process(es) in a second cell to concentrate said metal(s) of interest of said pregnant leach solution to produce a rich electrolyte and a raffinate solution, said raffinate solution being recycled in said first cell; and

(c) electrowinning in a third cell of said rich electrolyte received from said second cell and said acid-ferrous aqueous solution received from said first cell, for producing metal cathodes and an acid-ferric acid solution, said acid-ferric acid solution (9) being recycled in said first cell,

wherein said steps (a), (b) and (c) are performed in said autogenous circuit that includes said first, second and third cells with one or more anionic interfaces producing anodic and cathode reactions.

The solution circuit is closed between the different indicated steps. Mineral(s) or material(s) enter to be treated in the leaching stage (LX) and in general also a solution from the (SX) circuit and a one from the (EW) circuit with the oxidizing agent(s). This with the purpose of Leaching Metal(s) and material(s) and /or improve the grade of the compound(s) to be treated. To the Electrowinning stage, with the presence or not of separate chambers for the ionic exchange, enters a concentrate solution of the Metal(s) of interest; this solution corresponds to the Rich Electrolyte or catholyte and an aqueous solution of the lowest ion valence of the oxidizing agent(s). The use of an electric current allows the reduction of the Metal dissolved in the cathode and the simultaneous oxidation of the agent(s) that turn into dissolved oxidizing agent(s) over the surface of the anode and this oxidizing agent is recycled into the circuit so it can be reused in the Leaching process or other if suitable for the production needed. The circuits, with the purpose of maintaining a stable and high performance environment, may or may not incorporate unit operations (without limitations) of exchange (in and/or out) of mass and/or energy over the circuit described. Also, mechanisms and algorithms of control may or may not be used to achieve the effect wanted in an optimized way.

According to another aspect of the present invention, there is provided a method for use in an autogenous productive circuit configuration for the production of sulfur metals and materials that use ferric sulfate as an oxidizing agent generated electrolytically in a cell with ionic exchange membrane, said method comprising steps of: (a) acid-ferric leaching of the mineral or material including at least one of compounds, concentrates, tailings, white metal, cements, precipitates, scrap and sulfur minerals, through a conventional system of piles/dumps/reactors/vats; (b) solvent extraction (SX) to separate a rich electrolyte coming from the metal of interest (Cu, Mn, Zn, Co, Mo, Ni, etc.), (c) electrowinning(EW) done in a circuit of cells with anionic membranes for the production of Metal Cathodes. A raffinate solution enters the leaching stage coming from the SX circuit or other device and also a ferric solution coming from EW, where Metals are leached and/or the grade of the material or compound treated is improved. To the electrowinning stage a purified and concentrated (in the Metal Cu, Co, Mn, Mo and/or Zn among other metals and compounds) acid solution enters (this solution corresponds to the Rich Electrolyte or catholyte) and also an aqueous solution of sulfuric acid and dissolved ferrous sulfate or, anolyte. The use or an electric current allows the reduction of the Metal dissolved in the cathode and the simultaneous oxidation of the iron dissolved over the surface of the anode.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 is a block diagram illustrating the main hydrometallurgical operations used in conventional processes for the processing of sulfur copper minerals.

Figure 2 is a block diagram illustrating an autogenous process according to a preferred embodiment of the present invention.

Figure 3 is a block diagram illustrating an autogenous process according to another preferred embodiment of the present invention

THE INNOVATIVE PROCESS PROPOSED

The autogenous process disclosed in the present application involves leaching or dissolving compounds, concentrates, materials and minerals (considering metals) - such as: Cu, Mn, Zn, Co, Mo, Ni which are going to be referred to generally as Metals- by using oxidizing agents; which is possible to regenerate directly during the production of metallic cathodes and be used again as oxidizing agent in the leaching stage, by the use of one or many interfaces that are constituted by anionic membranes in an electrolytic cell. The circuits may or may not contain unit operations for the exchange of mass and energy. In Figure 3, this general and base scheme is presented, which as an illustration and without loss of generality, shows an autogenous process according to a preferred embodiment of the present invention.

A process according to another preferred embodiment of the present invention, as a general and base scheme, is also presented graphically in Figure 2.

Figure 3 presents a General Scheme of the Autogenous Process Proposed for Leaching Compounds, Concentrates and/or Metals. Without loss of generality and as an example, the legends in Figure 3 correspond to sulfur copper Minerals that allow the production of Copper Cathodes:

i) Main Operations: A- Leaching or Bioleaching in Piles and/or Dumps, B- Solvent Extraction and C- Electrowinning.

ii) Main Currents or Flows: 1- Material, Mineral, Concentrate or Dust with copper or other Metals, 2- PLS Solution, 3- Discarded Material, 4- Raffinate Solution, 5- Rich Electrolyte, 6- Copper Cathodes and 7- Weak Electrolyte, 8- Acid-Ferrous Aqueous Solution and 9- Acid-Ferric Aqueous Solution.

Two different solution circuits are available in Sub Process C and they are separated by a selective membrane. The purpose of this circuit design this is to balance the different operations in terms of the amount of acid and iron being dissolved, in addition to generating a Rich Electrolyte of the metal of interest (in some cases, there is more than one metal of interest) by means of the Solvent Extraction (SX) process, which separates the dissolved iron and other impurities contained in the PLS Solution that comes from Leaching. Indeed, Figure 3 contains two independent inner circuits:

Circuit A: Consists on Flow 8 and Flow 9

Circuit B: Consists on Flow 2, Flow 5, Flow 7 and Flow 4.

The Acid-Ferrous Aqueous Solution (Flow 8) is transformed into the Acid-Ferric Aqueous Solution (Flow 9) in Circuit A because of the interaction with Circuit B in Sub Process C; this is where the selective ionic exchange of sulfate ion (S0 ₂ ⁴ ) occurs because of the interface (membrane), that allows the ionic exchange without mixing the two different circuits.

In the electrolytic cell membrane semi-reactions are:

i) anodic reaction: 2Fe2 +— > + + 2 e 2Fe3

ii) cathode reaction: Cu2 + + 2e— > Cu °

In Figure 3, as an example and without loss of generality, two unit operations are illustrated:

Unit Operation M: Located in Flow 9, extract/incorporate mass from/into the flow.

Unit Operation E: Located in Flow 8, extract/incorporate energy from/into the flow.

However, in Figure 3 it is possible to incorporate new Unit Operations, to vary the circuits and/or flows and add control algorithms in order to: (a) achieve balance of mass and energy and (b) optimize operations. Without loss of generality, some examples would be: If a solution has an excess of iron, lack of sulfur or if a higher temperature is needed to optimize the Leaching process.

Flow 1 in Figure 3, contains Material, Mineral, Concentrate or Dust with copper or other Metal which are fed to the Sub Process A. Sub Process A consists on an acid- ferric leaching circuit in Reactors, Piles or Dumps. Here the materials containing Metals are leached by applying acid solutions (Flow 4) and ferric solutions (Flow 9) from the Solvent Extraction circuit (Sub Process B) and Electrowinning (Sub Process C).

From de Leaching produced in Sub Process A, as an example and without loss of generality, a solution containing copper sulfate (CuS0 ₄ ) is obtained at a concentration of 1-10 g/L which in the industry is known as PLS and is represented by Flow 2 in Figure 1.

Flow 3 corresponds to Discarded Material of the Leaching process; this material is transported to Dumps where a second process of Leaching could be attempted.

Flow 2 is fed to a Solvent Extraction circuit, which is indicated as Sub Process B in Figure 2. At this stage the solution that comes from the leaching is cleaned of impurities and concentrates its copper content, reaching 40-50 g/L Cu, by using extracting agents. To remove the copper from the PLS solution, it is mixed with a solution of organic (a mixture of extractant and high flash point paraffin, 10-30% vol.). The extracting agent captures the copper ions (Cu ⁺² ) selectively and generates a weak copper solution (Cu <0.5 g/L), known as Raffinate Solution (Flow 4), which is conditioned and recycled to the Leaching process. Subsequently, using a Weak Electrolyte acid solution (Flow 7) copper is discharged from the extractant, generating Flow 5 which is the Rich Electrolyte.

The Rich Electrolyte (Flow 5) with 40-50 g/L Cu concentration and the Acid-Ferrous Aqueous Solution (Flow 8) are processed by Electrowinning in a circuit with electrolytic cells with membrane (Sub Process C) in order to obtain the primary product consisting of a pulp or Copper Cathodes of high purity (99.99% Cu) (Flow 6). As sub-products of this: (a) A solution called Weak Electrolyte (Flow 7) is generated in the cathodic compartment, this solution is recycled to Solvent Extraction Sub Process B for its re- concentration of copper, (b) An Acid-Ferric Aqueous Solution (Flow 9) in the anode compartment is generated, which is recycled to the leaching circuit (Sub Process A). For more details of Membrane Electrowinning process see the developments by Cifuentes et al. 2004 and 2007 and Casas et al., 2008. Developments in the field of ion exchange membranes used in Electrowinning processes in cells with membrane (electrodialysis processes) can be found in the references of Lorrain et al, 1996 and Krol 1997.

In the electrolytic cell membrane semi-reactions are:

i) anodic reaction: 2Fe2 +— > + + 2 e 2Fe3

ii) cathode reaction: Cu2 + + 2e— > Cu ° Each semi-reaction occurs separately in its anion and cation compartment, respectively, which are separated by adding an anionic membrane located between the two compartments. This membrane is selective and allows the exchange of sulfate anions (S0 ₄ ^~2 ) from the catholyte to the anolyte, so as to achieve electro neutrality in the solutions while the electrolytic process of copper cathode formation develops and allowing recovery of the oxidizing agent ferric sulfate in Flow 9.

The capacity of the circuit as a whole allows the processing of sulfur minerals and concentrates of lower copper grades, which the industry is currently not being able to treat by means of hydrometallurgical processes. The new process achieves at a low cost a circuit that minimizes the Discard Material flow because it balances the different flow involved and uses Electrowinning cells with an interface, in particular using a membrane that allows regeneration of the oxidizing agent and therefore produce copper cathodes with less electric energy consumption.

This new process (see Figure 3), that incorporates in this patent application new unit operations to achieve optimized mass and energy balance, is based on the process illustrated in Figure 2 and allows to solve different problems of the extractive metallurgic industry in terms of the processing of minerals, sub-products and Metals that require the use of an oxidizing agent. In this patent application, as an example, the autogenous process uses the highly oxidizing ferric sulfate, which is recycled into the circuit at a low cost making possible the processing of additional resources compared to conventional hydrometallurgical technologies, incorporating or extracting mass and/or energy.

The procedure outlined, in addition to the usual materials, is suitable for processing various others materials and metallurgic resources like for example: scrap metal, cement, metal, foundry slag, shafts, matte and white metal casting, casting powders, anode sludge and sulfide minerals, in a circuit that includes acid-ferric leaching of these materials, generating rich solutions that are purified and concentrated with conventional technology of solvent extraction.

The Acid-Ferrous and Rich Electrolyte solutions obtained are processed by Electrowinning cells modified with the addition of ion exchange membranes to produce cathodes of metals and the regeneration of the oxidizing solution (Acid-Ferric solution) used in the Leaching materials listed.

Descriptions of the operation and performance of these electrolytic membrane cells are found in the following publications and patents: United States Patents: N° 5,961 ,833; N° 6,306,282;N° 6,355,175; N° 3,957,504; N° 4,684,450; N° 4,968,008; N° 5,039,337; N° 5,372,684; N° 5,718,874; N° 5,762,683; N° 5,492,608; N° 6,159,356; N° 7,368,049. European patents: EPO 415482 A1 ; ES 2 035. Chilean patent N° 336; Chilean patent application 199600852. Papers: Cifuentes et al.,(2004, 2007), Lorrain et al., (1996) and Krol et al., (1997).

It is noteworthy that in the consulted papers and patents there is no disclosure or use of a circuit incorporating unit operation configurations as the ones proposed in this patent application. There are several processes that use ferric sulfate as an oxidizing agent; however, this reagent is generated inside the Leaching reactor through the application of oxygen and temperature, chlorine or by using iron-oxidizing microorganisms. Also, the developments made in the electrolyte membrane reactors to produce Metal Cathodes, focus on cell design and its various operating conditions, not considering the aspects of overall balance in a circuit of self-processes in terms of balanced use of the oxidizing agent from Leaching to Electrowinning operations, which corresponds to the innovation presented in this patent application.

The current state mentioned in the consulted bibliography and patent documents (US- US-7368049, US-6159356 and US-5494608) describe processes which do not produce ferric sulfate in high concentrations. On the other hand, in the proposed patent application this is a new possibility, which allows using the ferric sulfate (produced in the new Electrowinning) in the Leaching process where it is going to be reduced into ferrous sulfate.

Thus, specifically an interface, in particular and without loss of generality based membrane, allows the interchange(s) ionic(s) specified(s) that simultaneously generate or re-oxidizing agent(s) with reactions in the camera (or without camera) of catholyte in the camera (or without camera) anolyte, goal the metal electrowinning of interest at a low operational cost.

The differences between the patent (US-7.368.049) and the one presented

It is noteworthy that the present application also applies to various metals such as: Zn, Co, Ni, Mn, Mo, among others. The procedures indicated in the patents US-7.368.049 and US-6.159.356 are also applicable to the copper case.

This process is highly versatile concerning to the type of metallurgical resource to be processed and is built in a modular way for each application of industrial interest, through a system that uses a combination of stages, series-parallel schemes of its component equipments and recycling of the solutions to the different parts of the circuit, to achieve a circuit configuration that allows precise balance of the materials in the process (closed circuit, without discarding contaminants).

The proposed process (among other things, depending on the oxidizing agent and specific ions in the ionic exchange) can be used for the production of metallic cathodes and/or base metal powders, such as: Cu, Zn, Co, Ni, Mo; materials and metallurgical products (concentrates of Cu, Zn, Co, Ni, Mo; intermediate materials of the smelters, slag, white metal, anode sludge). This production can be done adjusting its copper grade and level of impurities to commercial values.

The present patent application has as an innovation the use of a cell with one or many interfaces, generally composed of an ionic membrane that regenerates in a clean way the ferric sulfate solution (anolyte), which when is free of copper it can be reused directly for the Leaching of minerals, concentrates and materials that contain copper or other Metals.

The main supplies required for the proposed process are: Leaching metallurgical materials, electricity, process water, technical grade sulfuric acid, ferrous sulfate (initial filling of the pond and small offset potential losses), anion exchange membrane (initial and annually replenished) and Solvent extraction SX (initial filling of the pond and small potential losses and evaporation), Electrowinning additives (tuner guar bean type), replacement of anodes (graphite or equivalent) and cathode foils mother/white (stainless steel sheets).

The technical problem and the invention in this patent application consist in:

i) An autogenous process to leach or dissolve compounds, concentrates, materials and minerals through the use of oxidizing agents.

ii) The oxidizing agents regenerate directly during the production of metallic cathodes in a chamber using one or many interfaces that allow the processing of a solution with one or many oxidizing agents suitable for the mineral of interest. The invention is centered in the circuits, being the recycling of the oxidizing agent, without loss of generality, ferric sulfate, necessary to support the process of metal dissolution, so an integral and sustainable process was designed and it allows the regeneration of the oxidizing agent taking advantage of a part of the energy necessary to achieve the production of the cathode. For achieving this production an electrolytic cell with interface(s) is needed; without loss of generality, membranes that allow ionic exchange. It is noteworthy that the configurations of the autogenous hydrometallurgical processes proposed in this patent application the ones that constitute and must be consider in the inventive analysis. These configurations are not known in the metallurgical industry and do not include the existence of unit operations, in the flows that constitute the circuits, that contribute to the mass and energy balances required to optimize the process of gathering cathodes of the metal of interest.

The configuration of new autogenous processes formulated in this patent application allows to solve different problems of the extractive metallurgical industry in terms of the processing of mineral resources, sub-products and metals that require the use of an oxidizing agent. In this application of an autogenous process as an example, without loss of generality, the highly oxidizing agent ferric sulfate is used and recycled into the circuit at a low cost, allowing the processing of additional resources unlike conventional hydrometallurgical technologies, resources such as sulfur minerals with a lower cut-off grade, concentrates or complex metallurgical materials. The industry is eager to reach out to a technology that provides productive schemes of low costs and that do not generate discard currents that require expensive neutralizing operations. The new process proposed is low cost, because the different flows in the productive circuit balance each other and use electrowinning cells with an interface that allows ionic exchange in particular through membranes that regenerate the oxidizing agent free from copper and also produce metallic cathodes with less electric energy consumption in comparison to the conventional technology applied in the copper plants of the current industry.

Since the present invention has several potential process configurations, and how these can be used in multiple circuits depending on the type of application required, it is understood that all matter herein described and illustrated in the diagrams annexed shall be construed by way of example. The scope of the claims should not be limited by the preferred embodiments set forth in the examples, but should be given the broadest interpretation consistent with the description as a whole. GLOSARY

Units

t/d Tons per day

% Mass percentage m ³ /d Cubic meters per day g/L Kilograms per liter

V Volts

Terms or Acronyms

EW Electrowinning

PLS Pregnant Leach Solution

SX Solvent Extraction

LX Leaching Process

Example 1 : Application to the Treatment of Copper and Metal Axe

Through this first example, it is shown the application of the proposed process to the processing of intermediate products of a foundry such as shafts, copper mattes or white metal. This particular process is presented with reference to the flow chart in Figure 2, which is performed at atmospheric pressure and temperature in the range of 20-90 ° C.

In this case, Figure 2 shows a general scheme of the autogenous proposed process that leaches copper mattes and white metal axes combined to the production of copper cathodes. The captions of this figure correspond to: i) Main Operations:

A- Acid-Ferric Leaching Circuit in Iron in Reactors or Piles,

B- Solvent Extraction Circuit and

C- Electrowinning circuit in cells with membranes,

ii) Currents or Main Flows: 1 - White metal or copper mates or Copper axes, 2 - PLS solution, 3- Secondary Leaching Material to rework in a Foundry, 4 - Raffinate Solution, 5 - Rich Electrolyte, 6 - Cathodes or Copper Pulp, 7 - Weak Electrolyte, 8- Acid-Ferrous Aqueous Solution and 9- Acid-Ferric Aqueous Solution.

In this process, the compound of interest (white metal, copper mattes or axes, corresponding to an intermediate material generated in the smelters) is leached in the acid-ferric solution from the cell in the electrowinning phase in cells with membrane. The rich solution generated in the leaching step is concentrated and purified by solvent extraction technology, so as to generate a rich and pure electrolyte with the metal of interest, which is then reduced in an electrolyte way in order to create metallic cathodes.

The following table provides a summary of the material balance applied to the treatment of white metal (FeS-Cu2S) to achieve a production of one ton per day of copper cathode (99.999% Cu).

Table 1 : Balance of Example 2 applied to the White Metal Treatment

Variable Unit Value

Copper cathode produced (9) t/d 1

Fedwhite metal (1 ) t/d 1.35 - 1.40

Percentage of copper in white metal % 75

Solution flow raffinate / PLS (3, 4) m ^a /d 12 - 24

Solution flow acid-ferric / ferrous (2, 5) m ^a /d 10 - 15

Electrolyte flow rich / poor (7, 8) m ^a /d 3 - 4

Concentration of dissolved iron in EW g/L 40 - 60

Secondary material leaching t/d « 0.04 - 0.08 Example 2: Application to the Treatment of Cement, Precipitates and scrap copper and other metals

Through this second example it is shown the application of the proposed process to the treatment of cement, precipitates and scrap metal. This particular process is presented with reference to the flow chart in Figure 2, which is performed at atmospheric pressure and temperature in the range of 20-90 ° C.

In this case, Figure 2 presents an overview of a General Scheme of the Proposed Autogenous Process to Leach Cement or Precipitates and Copper Scrap combined with the Production of Copper Cathodes. The captions of this figure correspond to: i) Main Operations:

A- Acid-Ferric Leaching Circuit in Reactors or Piles,

B- Solvent Extraction Circuits and

C- C- Electrowinning Circuit in Cells with Membrane ii) Currents or Main Flows: 1 - Cement or scrap copper, 2 - PLS solution, 3 - Residual Material Disposal, 4 - Raffinate Solution, 5 - Rich Electrolyte, 6 - Cathodes or Copper Pulp 7 - Weak Electrolyte , 8 - Acid-Ferrous Aqueous Solution and 9- Acid-Ferric Aqueous Solution.

In this process the compound of interest (cement, precipitated or copper scrap) is leached in the acid-ferric solution from the electrowinning phase in cells with membrane. The rich solution generated in the leaching step is concentrated and purified by solvent extraction technology, so as to generate a rich and pure electrolyte with the metal of interest, which is then reduced in an electrolyte way in order to create metallic cathodes.

The following table provides a summary of the material balance applied to the processing of copper cement in order to achieve the production of 1 ton per day of copper cathode (99.999% Cu).

Table 2: Balances in Example 2 applied to the Treatment of Copper Cement

Variable Unit Value

Copper cathode produced (9) t/d 1

Fed white metal (1 ) t/d 1.4

Percentage of copper in white metal % 75

Solution flow raffinate / PLS (3, 4) m ^a /d 12 - 24

Solution flow acid-ferric / ferrous (2, 5) m ^a /d 10 - 15

Electrolyte flow rich/poor (7, 8) m ^a /d 3 - 4

Concentration of dissolved iron in EW g/L 40 - 60

Leaching discard material disposal (6) t/d « 0.1 - 0.2 Example 3: Application to the Treatment of copper concentrates, tailings and smelter dusts

Through this third example it is shown the application of the proposed process to the treatment of metal concentrates. This particular process is presented with reference to the flow chart in Figure 2, which is performed at atmospheric pressure and temperature in the range of 20-90 ° C.

In this case Figure 2 shows a General Scheme of the Proposed Autogenous Process for Leaching Copper Concentrates, Casting Powder and/or Tailings combined with the Production of Copper Cathodes. The captions of this figure correspond to: i) Main Operations: A- Acid-Ferric Leaching Circuit in Reactors or Piles B- Solvent Extraction Circuit and C- Electrowinning Circuit in Cells with Membranes. ii) Currents or Main Flows: 1 - Copper Concentrates, Melting Powders and/or Tailings, 2- PLS solution, 3 - Secondary Disposal Material or rework leaching in the Smelter, 4- Raffinate Solution, 5 - Rich Electrolyte , 6- Cathodes or Copper Pulp, 7- Weak Electrolyte, 8- Acid-Ferrous Aqueous Solution and 9- Acid-Ferric Aqueous Solution.

In this process the compound of interest (copper concentrates, tailings and smelter dusts) is leached in the acid-ferric solution from the electrowinning phase in cells with membrane. The rich solution generated in the leaching step is concentrated and purified by solvent extraction technology, so as to generate a rich and pure electrolyte with the metal of interest, which is then reduced in an electrolyte way in order to create metallic cathodes.

The following table provides a summary of the material balances applied to processing of copper concentrate (composition 10% Cu2S, CuS 10%, 45% CuFeS2, Fe2S 25%, 5% gangue) considering a partial leaching of copper 50% to achieve production of 1 ton per day of copper cathode (99.999% Cu).

Table 3: Balance of Example 2 applied to the treatment of Copper Concentrate

Example 4: Application for the Treatment of copper sulfide minerals

Through this fourth example it is shown the application of the proposed process to treat low-grade sulfide ores. This particular process is presented with reference to the flow chart in Figure 2, which is performed at atmospheric pressure and temperature in the range of 20-60 ° C.

In this case Figure 2 presents an overview of a General Scheme of the Proposed Autogenous Process to Leach Cement or Precipitates and Copper Scrap combined with the Production of Copper Cathodes. The captions of this figure correspond to: i) Main Operations: A- Acid-Ferric Leaching Circuit in Reactors or Batteries or Dumps, B- Solvent Extraction Circuit and C- Electrowinning Circuit in Cells with Membranes. ii) Currents or Main Flows: 1- Copper Sulfide Ores 2- PLS Solution 3- Leaching discharge, 4- Raffinate Solution, 5- Rich Electrolyte, 6- Cathodes or Copper Pulp 7- Weak Electrolyte , 8- Acid-Ferrous Aqueous Solution and 9- Acid-Ferric Aqueous Solution.

In this process the compound of interest (copper sulfide minerals) is leached in the acid acid-ferric solution from the Electrowinning phase in cells with membrane. The rich solution generated in the leaching step is concentrated and purified by solvent extraction technology, so as to generate a rich and pure electrolyte with the metal of interest, which is then reduced in an electrolyte way in order to create metallic cathodes.

The following table provides a summary of the material balances applied to processing of copper ore of low grade (0.4% composition Cu2S, CuS 0.3%, 0.3% CuFeS2, Fe2S 3%, 96% gangue) considering a leaching 50% of copper so as to achieve a production of one ton per day of copper cathode (99.999% Cu).

Table 4: Balance of Example 2 applied to the Copper Ore Processing

Example 5: Application to Treatment Material Processing, Minerals and compounds formed with other metals, such as Zinc, Iron, Cobalt, Molybdenum and Nickel

Through this fifth example it is shown the application of the process proposed to the treatment of mineral or metallic materials containing copper, zinc, iron, cobalt, molybdenum and / or nickel. This particular process is presented with reference to the flow chart in Figure 2, which is performed at atmospheric pressure and temperature in the range of 20-90 ° C.

In this case Figure 2 shows a General Scheme of the Proposed Autogenous Process to Leach Materials, Minerals and compounds formed by zinc, iron, cobalt, molybdenum, copper and / or nickel production combined with the metallic cathode. i) Main Operations: A- Acid-Ferric Leaching Circuit in Reactors or Piles or Dumps, B- Solvent Extraction Circuit, C- Electrowinning Circuit In Cells with Membrane. ii) Currents or Main Flows: 1 - Metals and Minerals Sulfur (Cu / Fe / Zn / Co / Ni), 2 - PLS Solution, 3 - Secondary Leaching Material to discard (Floating / Leach / Cast), 4- Raffinate Solution, 5 - Rich Electrolyte, 6- Cathodes or Metal Pulp (Cu / Zn / Fe / Co / Mo / Ni), 7 - Weak Electrolyte, 8 - Acid-Ferrous Aqueous Solution 9- Acid-Ferric Aqueous Solution.

In this process the compound of interest (ores, concentrates and materials of zinc, cobalt and / or nickel) is leached in the acid-ferric solution from the electrowinning phase in cells with membrane. The rich solution generated in the leaching step is concentrated and purified by solvent extraction technology, so as to generate a rich and pure electrolyte with the metal of interest, which is then reduced in a electrolyte way in order to create electrolytic metal cathodes.

The material balance for this case will depend on the type of metallurgic metal or mineral to be processed, so as to adjust the solvent extraction and electrowinning operations to the production requirement, thereby generating the amount of oxidant (ferric sulfate) in the right measure for the leaching requirement.

In the case of treating materials of molybdenum (concentrates and / or minerals), this process allows dissolving the impurities associated with copper, zinc, iron, among others, in order to leave a clean solid product (concentrate and / or molybdenum ore) for further processing by roasting and/or leaching technology in order to recover the molybdenum content. BIBLIOGRAPHY

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