Dump leaching base-metal-containing material

Abstract

The invention relates to heap leaching of base metal containing materials. A two-stage dump leaching process for leaching a base metal from a base-metal-containing material. The method transfers at least a portion of the enriched leach solution from the first stage leach in the first stack or the leach solution produced after processing the enriched leach solution to the second stage leach in the second stack. The method controls the conditions in the first extraction stage and the second extraction stage to allow the method to operate efficiently, in particular, but not limited to, in cold climates, such as during the day and in cold climates where there are large temperature variations across seasons.

Description

TECHNICAL FIELD

[0001] The present invention relates to the heap leaching of base metals from base metal-containing materials, such as copper or nickel or zinc or cobalt, where the term "material" includes, for example, ores and wastes, such as tailings and mineralized wastes.

[0002] The present invention particularly but not exclusively relates to the heap leaching of base metal-containing materials in cold climates, especially in cold climates with large temperature variations, which include climates having temperatures in the range from very cold to very hot, where heat generation in the heap and heat loss from the heap are key considerations, and where in some cases cooling the heap may be a key consideration.

[0003] The present invention particularly but not exclusively relates to the heap leaching of copper-containing materials.

[0004] The base metal-containing material can be (a) run-of-mine ("ROM") material or (b) ROM material that has undergone intermediate processing, the terms "ROM material" and "intermediate processing" being understood herein - see below.

[0005] The base metal-containing material can be material in a stockpile of ROM material or ROM material that has undergone "intermediate processing".

[0006] As mentioned above, the base metal-containing material can be an ore.

[0007] As mentioned above, the base metal-containing material can be a waste, such as tailings or mineralized waste, and it is uneconomical to process the waste using current processes employed at mines that mine the mineralized waste.

[0008] The present invention also particularly but not exclusively relates to heap leaching agglomerates of base metal-containing materials.

[0009] The present invention also relates to the recovery of base metals, such as copper, from leached base metal-containing materials.

[0010] The present invention also relates to end-use products made from recovered base metals such as copper. BACKGROUND ART

[0011] The technical field of the present invention is the production of base metals, such as copper or nickel, zinc or cobalt, from base metal-containing materials, such as metal sulfide minerals in run-of-mine ("ROM") materials or ROM materials that have undergone intermediate processing.

[0012] The technical field of the present invention also includes the recovery of rare earth elements, scandium, manganese, etc., which are present in base metal-containing materials and can be economically recovered.

[0013] The following description focuses on copper as an example of a base metal in base metal-containing materials.

[0014] The copper-containing material can be a copper sulfide-containing material.

[0015] As described later herein, the copper-containing material can be a copper oxide-containing material.

[0016] The copper-containing material can be a combination of a copper sulfide-containing material and a copper oxide-containing material.

[0017] For mine operators of well-established copper mines and new copper mines (the term includes mines where copper is the only metal recovered and mines where copper and other valuable metals such as gold are recovered) with a lower average concentration of copper in the copper-containing material compared to previous cases, there are significant pressures on capital costs and operating costs.

[0018] In many cases, the problem of lower copper concentration in the copper-containing material is complicated compared to previous cases by an increasing proportion of copper in more refractory copper-containing minerals such as, but not limited to, chalcopyrite, where processing these minerals to recover copper from the minerals is more difficult and expensive.

[0019] Mining companies are also well aware of the importance of operating mines with minimal environmental impact in the short and long term, and this has implications for the recovery options and costs.

[0020] The economic problems faced by copper mine operators mean that there is a large amount of copper-containing material, including copper-containing material in the form of mined material, intermediate processing of mined material (i.e., crushed material), including such materials in stockpiles, which are uneconomical to recover copper from using the recovery options available before the present invention was made, and are therefore not processed to recover copper from the copper-containing material.

[0021] Heap leaching is an option for dissolving copper in the copper-containing material, where downstream method steps recover copper from the solution, and where the recovered copper is subsequently formed into a final use product.

[0022] In conventional heap leaching of copper sulfide-containing materials, which is understood herein to include dump leaching, the copper sulfide-containing materials are piled into a heap, aerated by direct injection of air via an air injection pipe extending into the heap and / or by natural convection through the exposed areas of the heap, and irrigated with an acidic leaching solution for extracting copper into the solution. The leaching process requires acid and an oxidizing agent to dissolve the copper into the solution. Subsequently, copper is recovered from the copper-containing solution (i.e., the enriched leaching solution) collected from the heap through a series of recovery options, which include, for example, solvent extraction and electrowinning (SX / EW), cementation onto a more reactive metal such as iron, hydrogen reduction, sulfidation via addition of H2S or NaHS, crystallization of sulfates, and direct electrowinning. The resulting copper-depleted solution, i.e., the raffinate in the case of SX processing, is regenerated into an acidic leaching solution and recycled through the heap to leach more copper from the copper-containing materials in the heap. The materials in the heap can include ROM materials, ROM materials that have undergone intermediate processing, or agglomerates of these materials. Leaching can be assisted by adding ferrous and sulfur-oxidizing microorganisms.

[0023] In conventional heap leaching of copper oxide-containing materials, which is understood herein to include heap leaching, the copper oxide-containing materials are piled into a heap and irrigated with an acidic leaching solution for extracting copper into the solution. The leaching process requires acid to dissolve the copper into the solution. Subsequently, copper is recovered from the copper-containing solution (i.e., the enriched leaching solution) collected from the heap through a series of recovery options, which include, for example, solvent extraction and electrowinning (SX / EW), cementation onto a more reactive metal such as iron, hydrogen reduction, and direct electrowinning. The recovered copper is then formed into a product for end use. The resulting copper-depleted solution is regenerated into an acidic leaching solution and recycled through the heap to leach more copper from the copper-containing materials in the heap. The materials in the heap can include ROM materials, ROM materials that have undergone intermediate processing, or agglomerates of these materials.

[0024] Generally, heap leaching provides lower metal recovery rates than other metallurgical options for recovering copper from copper-containing materials, such as milling and flotation to produce a copper-containing concentrate, which is then smelted to produce copper metal.

[0025] Therefore, heap leaching tends to be reserved for lower-grade materials that have at least a certain proportion of copper that is easily recoverable, but where the crushing / milling cost per unit of copper (or copper equivalent - i.e., when considering by-product credits from, for example, gold and silver) is too high to support a concentrator method, or where mineral liberation and other characteristics (e.g., arsenic content) will not support the production of a directly usable or marketable concentrate.

[0026] Heap leaching of copper sulfide-containing materials and copper oxide-containing materials requires different operating parameters.

[0027] Operating parameters include, by way of example, the temperature of the acidic leach solution, the leach solution irrigation rate, the acid concentration, aeration and the aeration rate (if aeration is required), the pH of the leach solution, the E of the leach solution h and additives in the heap such as microorganisms and sulfide-containing additives such as pyrite and sulfide-containing additives obtained from any suitable source such as the cleaner scavenger tails from a concentrator circuit. An important consideration is the selection of operating parameters for a given material.

[0028] Another important consideration is the selection and control of operating parameters for the heap leaching of copper-containing materials, taking into account the requirements of downstream options for recovering copper from the enriched leach solution from the heap.

[0029] Another important consideration is the temperature control within the heap and the heat transfer between the inside and outside of the heap, especially in cold climates and particularly where there are large temperature variations during the day and across seasons.

[0030] The present disclosure relates to providing a method for heap leaching of base metal materials such as copper-containing materials in cold climates, especially where there are large temperature variations during the day and across seasons.

[0031] The above description should not be taken as an admission of common general knowledge in Australia or elsewhere.

[0032] Overview of the disclosure

[0033] The following overview of the present disclosure continues to focus on copper as an example of a base metal in metal-containing materials, where the term "copper-containing material" encompasses copper sulfide-containing materials and copper oxide-containing materials in any form (as described herein), such as copper minerals, clays, carbonates, silicates, etc.

[0034] The term "copper oxide-containing material" is understood herein to mean a material in which copper and oxygen are present in oxide form and in other forms, such as carbonates (including malachite), silicates (including chrysocolla), and copper in manganese / iron oxide phases, as well as water-soluble copper (CuSO4), etc.

[0035] Extracting copper from copper oxide-containing materials requires an acid such as sulfuric acid to decompose the mineral matrix and dissolve the copper.

[0036] For example, for malachite, the reaction is as follows:

[0037]

[0038] For example, for azurite, the reaction is as follows:

[0039]

[0040] Extracting copper from copper sulfide-containing materials is more complex than from copper oxide-containing materials and requires oxidants such as ferric ions and acids such as sulfuric acid to decompose the copper sulfide-containing mineral matrix and dissolve the copper.

[0041] Oxidants such as ferric ions, and acids such as sulfuric acid, are consumed during mineral oxidation and the dissolution rate decreases unless they are replenished.

[0042] Under aerobic conditions, microorganisms (such as acidophilic bacteria and archaea, more specifically members of the bacterial genera Acidithiobacillus, Leptospirillum, and Sulfobacillus, and members of the archaeal genera Acidianus, Acidiplasma, Ferroplasma, Metallosphaera, Sulfolobaceae, and Thermoplasma) regenerate ferric ions and acids and generate heat through the biological oxidation of ferrous ions (such as from pyrite FeS2 or chalcopyrite CuFeS2) and sulfur compounds (including elemental sulfur) as follows:

[0043] 2Fe 2+ +2H + +0.5O2 → 2Fe 3+ +H2O

[0044] 2S + 3O2 + 2H2O → 2H2SO4.

[0045] Sulfur compounds can be derived from the oxidation of sulfide minerals (such as pyrite), or as additives from any source (such as elemental sulfur), such as the selected scavenger tailings from a concentrator circuit.

[0046] Additional materials (additives) can be added to enhance copper dissolution, and some of these additional materials can include sulfur. Examples of such additives include sulfur-containing inorganic compounds such as thiosulfate or polythiosulfate or polysulfide, or sulfur-containing organic compounds such as thiourea or other thiocarbamide.

[0047] In summary, for copper sulfide-containing materials:

[0048] (a) During the mineral dissolution that releases copper into solution, ferric ions are reduced to ferrous ions and sulfuric acid is produced, and

[0049] (b) When present under aerobic conditions, the microorganism oxidizes ferrous ions to ferric ions, oxidizes available solid and soluble sulfur compounds, and produces sulfuric acid.

[0050] In summary, sulfur oxidation produces acid, and the reaction that converts ferrous ions to ferric ions consumes acid.

[0051] As described above, the present invention relates particularly but not exclusively to heap leaching operations in cold climates, particularly cold climates with large temperature variations during the day and across seasons, including very cold climates with large temperature variations in the range from very cold to very hot, where heat generation in the heap and heat loss from and to the heap are key considerations, particularly when using microorganisms in the heap.

[0052] The present invention is a two-stage heap leaching method that transfers at least a portion of the enriched leach solution from the first-stage leaching in the first heap or the leach solution produced after processing the enriched leach solution to the second-stage leaching in the second heap, and controls the conditions in the first leaching stage and the second leaching stage to allow the method to operate effectively, particularly but not exclusively in cold climates, such as cold climates with large temperature variations during the day and across seasons.

[0053] Broadly speaking, the present invention provides a method for heap leaching copper from copper-containing material from a mine, the method comprising:

[0054] (a) subjecting a first heap of a portion of the copper-containing material to microbiologically assisted aerated leaching with an acidic leach solution, wherein the microorganism produces ferric ions, wherein the acid and ferric ions dissolve the copper in the copper sulfide-containing material in the copper-containing material and produce ferrous ions, and wherein pyrite or other iron-containing minerals in the material or added to the material produce ferrous ions, acid, and heat,

[0055] (b) collecting a first enriched leach solution containing copper in solution from the first heap,

[0056] (c) subjecting a second heap of another portion of the copper-containing material to leaching with an acidic leach solution, the acidic leach solution comprising at least a portion of the first enriched leach solution from the first heap or the leach solution produced during processing of the first enriched leach solution to recover copper from the first enriched leach solution (e.g., the leach solution can be the raffinate produced in a solvent extraction circuit for recovering copper from the enriched leach solution), wherein the acid and ferric ions dissolve the copper in the material, consume excess acid, and reduce the neutralization requirement,

[0057] (d) collecting a second enriched leach solution containing copper in solution from the second heap, and

[0058] (e) Recover copper from one or both of the enriched leach solutions from the first or second heap.

[0059] In both heaps, due to the reaction between ferric ions and acid, copper in the material enters the solution, and there is at least biooxidation of sulfides (such as pyrite) in the first heap, which produces ferric ions, acid, and heat.

[0060] The term "mine" is understood herein as a broad term that, by way of example only, encompasses the following locations: (a) an area being mined (above and / or below ground) from which material is being removed; (b) an area that has been mined (above and / or below ground) from which material has been removed; (c) stockpiles of mined material from area (a) and area (b); (d) downstream processing unit operations, including, for example, any one or more comminution operations (such as crushers and grinders) for comminuting the mined material, sizing operations for separating the mined and comminuted mined material according to size, mineral processing operations such as flotation circuits, heap leaching operations, pressure oxidation units, and solvent extraction and electrowinning operations, and (e) storage facilities for reagents, water, enriched leach solution (PLS), concentrates of valuable metals, and tailings.

[0061] The term "acidic leach solution" is understood herein to mean any solution containing acid. The solution can be obtained from any suitable source or combination of sources. One source can include a second enriched leach solution from the second heap or another heap. Another source can include water from other sources on site, such as mine runoff, tailings dam solution and recycle, acid mine drainage, mine water, discharge streams, and other water sources related to and unrelated to mining operations. Another source can be the raffinate from a solvent extraction circuit used to recover copper from the enriched leach solution.

[0062] The copper-containing material can be a copper sulfide-containing material.

[0063] As described herein, the copper-containing material can be a copper oxide-containing material.

[0064] The copper-containing material can be a combination of a copper sulfide-containing material and a copper oxide-containing material.

[0065] The copper sulfide-containing material can include a copper-containing material that contains primary and secondary copper sulfide minerals, such as chalcopyrite (CuFeS2), enargite (Cu3AsS4), tetrahedrite ((Cu,Fe,Zn,Ag) 12 Sb4S 13 )、tennantite (Cu 12 As4S 13) Chalcopyrite (Cu5FeS4), chalcocite (Cu2S), covellite (CuS), bismuthinite (CuBiS2), or any combination thereof.

[0066] The copper oxide-containing material may include a copper-containing material that contains copper oxide minerals such as malachite (Cu2CO3(OH)2), azurite (Cu3(CO3)2(OH)2), cuprite (CuO), atacamite (Cu2Cl(OH)3), and chrysocolla (Cu2H2Si2O5(OH)4).

[0067] The copper oxide-containing material may contain copper clay.

[0068] The copper oxide-containing material may contain silicate.

[0069] The copper oxide-containing material may contain sulfate.

[0070] The copper oxide-containing material may contain chloride.

[0071] The copper oxide-containing material may contain native copper.

[0072] The copper oxide-containing material may contain copper metal.

[0073] The copper oxide-containing material may contain copper locked in other mineral phases such as chlorite, goethite, manganese oxide, psilomelane, and fayalite.

[0074] The copper-containing material in one heap may be different from the copper-containing material in another heap.

[0075] For example, the copper-containing material in the first heap may be a copper sulfide-containing material and a copper oxide-containing material.

[0076] In addition or alternatively, the copper-containing material in the second heap may be a copper oxide-containing material and a copper sulfide-containing material.

[0077] The copper-containing material in the first heap may be mainly a copper sulfide-containing material.

[0078] The copper-containing material in the second heap may be mainly a copper oxide-containing material.

[0079] It should be noted that the separation of the copper-containing material into the first and second heaps can be based on gangue mineralogy as well as copper mineralogy.

[0080] An advantage of the present invention is that by appropriately selecting leaching conditions, it is possible to process the copper sulfide-containing material in one heap and the copper oxide-containing material in another heap.

[0081] The present invention provides an opportunity to process copper-containing materials (such as copper sulfide-containing materials) that typically consume a large amount of acid in one heap and copper-containing materials (such as copper oxide-containing materials) that typically consume a relatively small amount of acid in another heap. This is an advantage of the present invention because it provides an opportunity to appropriately process both higher acid-consuming materials and lower acid-consuming (or acid-producing) materials separately in the heap, and the higher acid-consuming materials and lower acid-consuming (or acid-producing) materials are connected in terms of the flow of the acidic solution from one heap to another.

[0082] When processing copper oxide-containing materials in a flotation circuit to produce concentrates, the copper oxide-containing materials and some gangue associated with the copper-containing materials are often problematic. Therefore, it is advantageous to operate the leaching of the copper-containing materials in a heap as an opportunity to improve the overall recovery rate and product quality.

[0083] It is also advantageous to use the first enriched leaching solution from the first heap or the leaching solution generated during the processing of the first enriched leaching solution from the first heap as the acidic leaching solution in the leaching of a second separate heap. Among other things, this provides an opportunity to reduce the downstream acid neutralization requirement.

[0084] In other words, performing leaching in the second heap is an advantageous way to neutralize the first enriched leaching solution from the leaching in the first heap, that is, to control the pH and sulfates by consuming the acid and iron in the first enriched leaching solution in the leaching of the second heap, noting that both are key considerations for maintaining microbial activity.

[0085] The recovery step (e) of the method may include processing the first enriched leaching solution from the first heap to remove copper in a copper removal circuit and transferring at least a portion of the copper-depleted leaching solution to the second heap to be used as at least a portion of the acidic leaching solution.

[0086] For example, when the copper removal circuit is a solvent extraction circuit, the copper-depleted leaching solution is the raffinate, and the method may include transferring at least a portion of the raffinate to be used as at least a portion of the acidic leaching solution.

[0087] The copper-containing materials in one or both heaps may be copper sulfide-containing materials and copper oxide-containing materials. In other words, the heap may have two types of copper-containing materials. Generally, one type of material will be the main component of the copper-containing materials in one heap or the other heap, and the leaching method will be selected to leach this type of material.

[0088] The method may include transferring at least a portion of the first enriched leaching solution from the first heap to be used as at least a portion of the acidic leaching solution of the first heap.

[0089] The method can include transferring at least a portion of the second enriched leach solution from the second heap to be used as at least a portion of the acidic leach solution for the first heap.

[0090] The first enriched leach solution from the first heap or the leach solution generated during processing of the first enriched leach solution can include ferric ions that assist in dissolving copper in the copper-containing sulfide materials in the copper-containing materials in the second heap.

[0091] The method can include sorting the copper-containing materials before transferring them to the first or second heap and transferring the selected sorted materials to one heap or the other (including via stockpiles of the heap) or to a waste heap.

[0092] The method can include sorting the materials based on their suitability for leaching in the first or second heap.

[0093] For example, the method can include sorting the copper-containing materials based on whether the materials are copper-containing sulfide materials or copper oxide materials.

[0094] The method can include any suitable sorting technique at any suitable location upstream of the heap.

[0095] For example, the method can include sorting the copper-containing materials based on mineralogy or composition.

[0096] As a specific example, the method can include sorting the copper-containing materials based on acid-soluble copper concentration as an indication of whether the materials are copper-containing sulfide materials or copper oxide materials.

[0097] As a specific example, the method can include sorting the copper-containing materials based on cyanide-soluble copper concentration as an indication of whether the materials are secondary copper-containing sulfide materials.

[0098] As a specific example, the method can include sorting the copper-containing materials based on acid-soluble copper concentration and cyanide-soluble copper concentration as an indication of whether the materials are primary copper-containing sulfide materials.

[0099] As a specific example, the method can include sorting the copper-containing materials based on elemental composition or mineral composition as an indication of whether the materials are acid-consuming materials or acid-producing materials.

[0100] As a specific example, the method can include sorting the copper-containing materials based on the potential of the copper-containing materials to generate / consume heat in the first or second heap.

[0101] As a specific example, the method can include sorting the copper-containing materials based on elemental composition or mineral composition as an indication of whether the materials may have a negative or positive impact on extraction and recovery.

[0102] As a specific example, the method can include sorting the copper-containing material based on its elemental or mineral composition as an indication of whether the material is likely to have a negative or positive impact on solution and air flow / permeability within the heap.

[0103] The method can include sorting the copper-containing material selected for a heap before transferring the selected sorted material to the heap (including via a stockpile) or to a waste pile.

[0104] As a specific example, the method can include sorting the copper-containing material selected for a heap based on the copper grade (i.e., copper concentration) of the material and transferring the material having a copper grade higher than a threshold grade to the heap.

[0105] In such cases, it may be useful to perform grade sorting of the copper-containing material selected for a heap where there are large grade differences in known copper sulfide or copper oxide materials.

[0106] The method can include transferring the copper-containing material having a copper grade lower than the threshold grade to a waste pile.

[0107] The method can include controlling leaching in the first or second heap according to any one or more of acidic leaching solution temperature, acidic leaching solution irrigation rate (including optional use of a remaining rinse cycle), aeration rate, acid addition rate, acid concentration, pH of the acidic leaching solution, E h , the ratio of ferric iron to ferrous iron, and the addition of any other additives such as microorganisms and sulfide-containing additives such as pyrite, where the sulfide-containing additives are obtained from any suitable source such as selected scavenger tailings from a concentrator circuit, noting that some of these parameters are interrelated and noting cases where the terms "acidic leaching solution", "leaching solution" include situations where the leaching solution can also be described as an "enriched leaching solution", "raffinate", and "intermediate leaching solution".

[0108] For example, the method can include controlling leaching by controlling acidic leaching solution temperature, acidic leaching solution irrigation rate (including optional use of a remaining rinse cycle), aeration rate, acid addition rate, acid concentration, pH of the first enriched leaching solution and / or pH of the second enriched leaching solution, E h, the ratio of ferric iron to ferrous iron, the composition of the acidic leaching solution, and the addition of any other additives to the heap, such as microorganisms and sulfide-containing additives - for example, pyrite - where the sulfide-containing additives are obtained from any suitable source, such as selected scavenger tailings from a concentrator circuit), noting that some of these parameters are interrelated and noting the cases where reference is made to the acidic leaching solution, the "leaching solution" including the acidic leaching solution may also be described as an "enriched leaching solution", a " raffinate", and an "intermediate leaching solution".

[0109] The term "average" temperature is understood herein to take into account the possible temperature variations through the heap, and thus, for example, an average temperature of 50 °C takes into account that the temperature in one part of the heap may be different from the temperature in another part of the heap, and the average temperature is the average of many temperature measurements in the heap.

[0110] The method may include controlling the leaching in the first heap such that the temperature of the first enriched leaching solution is the target temperature when discharged from the first heap.

[0111] The method may include controlling the leaching in the first heap such that the temperature of the first enriched leaching solution is above a threshold temperature when discharged from the first heap.

[0112] The threshold temperature may be selected according to the requirements of leaching in the first heap.

[0113] The threshold temperature may be selected according to the requirements of leaching in the second heap.

[0114] The threshold temperature may be selected to provide sufficient heat to maintain the desired heap temperature in the second heap, especially in cases where the ability to generate heat in the second heap is limited.

[0115] The method may include generating sufficient heat in the first heap such that the first enriched leaching solution discharged from the first heap has sufficient heat to maintain the required operating temperature when used as the acidic leaching solution in the second heap.

[0116] The method may include providing heat from other sources such that both heaps have sufficient heat to maintain the required operating temperature in the heap.

[0117] The first enriched leaching solution may be at a temperature of at least 20 °C, typically at least 30 °C, and more typically at least 50 °C when discharged from the first heap.

[0118] The first enriched leaching solution may be at a temperature in the range of 50 °C - 60 °C when discharged from the first heap.

[0119] Consuming the heat of the first enriched leaching solution from the first heap as the acidic leaching solution in the second heap in the second heap provides an opportunity to effectively use heat in the process and reduce the temperature of the second enriched leaching solution discharged from the second heap to the optimal temperature range for downstream copper recovery steps (c) such as solvent extraction. This may avoid the need to cool the second enriched leaching solution discharged from the second heap before it is used in the downstream copper recovery step (e).

[0120] The method may include controlling the leaching in the second heap such that the temperature of the second enriched leaching solution is the target temperature when discharged from the second heap.

[0121] The method may include controlling the leaching in the second leaching such that the temperature of the second enriched leaching solution is below a threshold temperature when discharged from the second heap.

[0122] The threshold temperature may be a temperature selected in consideration of the operating requirements of the recovery step (c) such as solvent extraction.

[0123] The threshold temperature may be 40°C - 50°C when discharged from the second heap.

[0124] The method may include controlling the temperature in the first heap by cooling the heap.

[0125] The method may include controlling the temperature in the second heap by cooling the heap.

[0126] The method may include controlling the pH profile of the acidic leaching solution in the first and second heaps by monitoring and controlling the acidity of the leaching solution supplied to the first heap 21 and / or the acidity of the enriched leaching solution from the heap.

[0127] The method may include controlling the precipitation reaction (e.g., jarosite) and acid-producing reaction (sulfide minerals) in the heap.

[0128] The method may include controlling heat transfer, e.g., increasing or decreasing heat loss via aeration and acidic leaching solution application rate. This enables manipulation of the precipitation reaction (e.g., jarosite) and acid-producing reaction (sulfide minerals).

[0129] The method may include controlling the air entering the heap to promote iron oxidation.

[0130] The method may include controlling the E in the heap h including operating in a wide E h range in the heap.

[0131] The method may include controlling the precipitation chemistry in the second heap to control impurities (metal sulfates) - this reduces the neutralization requirement.

[0132] The method can include adding carbonate ore to the heap to promote bacterial growth.

[0133] The method can include using the mineralogy of the materials in the heap to inform the hydrodynamic behavior in the heap.

[0134] The method can include recycling the leaching solution between the heaps to increase the metal content, reduce water consumption / improve water efficiency, control acidity, and control impurities.

[0135] The method can include blending the materials for the first heap and / or the second heap to achieve a certain level of a sulfide-containing additive such as pyrite.

[0136] The method can include aerating the first heap by supplying air to the heap via forced aeration.

[0137] The method can include aerating the second heap by supplying air to the heap via forced aeration.

[0138] The method can include aerating the first heap via natural circulation of air entering the heap from outside the heap.

[0139] The method can include aerating the second heap via natural circulation of air entering the heap from outside the heap.

[0140] The acidic leaching solution can be any suitable acidic leaching solution.

[0141] As described in the definition of "acidic leaching solution" above, the acidic leaching solution can include, but is not limited to, site runoff, tailings dam solution and recycle, acidic mine discharge, mine water, discharge water flow, and other water sources related to and unrelated to mining operations.

[0142] As a specific example, the acidic leaching solution can be an enriched leaching solution.

[0143] As a specific example, in the case of recovering metals such as copper from the enriched leaching solution in the heap leaching step (b), the acidic leaching solution can be raffinate.

[0144] An example of a suitable acid is H2SO4.

[0145] The acid can be any other suitable inorganic acid or suitable organic acid.

[0146] The method can include controlling the acid concentration in the acidic leaching solution for the first heap and / or the second heap at an acid dosage rate of less than 100 kg H2SO4 / dry test material, usually less than 50 kg H2SO4 / dry test material, usually less than 30 kg H2SO4 / dry test material, and can be less than 10 kg H2SO4 / dry test material, or less than 5 kg H2SO4 / dry test material. Generally, the acid dosage rate is 1 - 20 kg H2SO4 / dry test material.

[0147] The method can include recovering copper from that portion (if any) of the enriched leaching solution from the first heap that is not transferred to the second heap.

[0148] The method can include minimizing heat loss of the first enriched leaching solution from the first heap when transferring it to the second heap.

[0149] The method can include forming the heap with a cover (such as a thermal film or snow cover) and controlling the aeration of the heap.

[0150] The method provides an opportunity to increase the dissolution of iron-containing sulfide minerals that may contain copper (such as copper contained in chalcopyrite).

[0151] The method provides an opportunity to increase the dissolution of iron-containing non-sulfide minerals and non-iron non-sulfide minerals that may contain copper (such as copper contained in malachite, jarosite, goethite, biotite, illite, ferrosilite, kaolinite, montmorillonite, chlorite, psilomelane, and manganese oxides).

[0152] The method can include adding acid to the acidic leaching solution for the second heap. In the case where the recovery step (e) includes solvent extraction, adding acid to the second heap provides an opportunity to improve the pH profile of the first enriched leaching solution used as the acidic leaching solution in the second heap and control the outlet pH supplied to the solvent extraction.

[0153] The method can include recovering copper from the enriched leaching solution by any suitable recovery method.

[0154] A recovery method can include solvent extraction and electrowinning (SX / EW) of copper.

[0155] In the context of copper, the term "solvent extraction and electrowinning (SX / EW)" is understood herein to include a two-stage hydrometallurgical process of a first stage of solvent extraction and a second stage of electrowinning.

[0156] The term "solvent extraction" is understood herein to mean the extraction of copper ions from an enriched leach solution into a solvent containing a chemical that selectively reacts with and binds the copper in the solvent.

[0157] The term "electrowinning" is understood herein to mean the process of depositing copper from a copper-containing solution onto a cathode by passing an electric current through it using an insoluble anode. The product copper is typically described as "cathode".

[0158] More specifically, the recovery method can include extracting copper from the first enriched leach solution and / or the second enriched leach solution with a solvent, and producing a metal-containing solvent stream and a raffinate.

[0159] The recovery method can also include stripping copper from the solvent and forming a metal-containing solution, and electrowinning copper from the metal-containing solution, where typically the copper is a copper cathode.

[0160] The recovery method can also include transferring the raffinate to the first heap.

[0161] The recovery method can also include transferring the raffinate to the second heap (i.e., bypassing the first heap).

[0162] As an example, other recovery methods include extracting copper from the first enriched leach solution and / or the second enriched leach solution by: (a) cementation onto a more reactive metal such as iron, (b) hydrogen reduction, (c) sulfidation via addition of H2S or NaHS, (d) crystallization of sulfates, and (e) direct electrowinning.

[0163] The present invention also relates to end-use products made from copper recovered by the recovery method.

[0164] The end-use product can be any suitable end-use product.

[0165] The end-use product can be further processed into other end-use products.

[0166] As described above, electrowinning copper produces a product called "cathode". The cathode is in the form of an end-use product because it is a salable product that can be sold to downstream manufacturers of other end-use products.

[0167] For example, the cathode can be processed in any suitable way to produce other end-use products, including billets, ingots, rods, and tubes, each of which can be resold to downstream manufacturers of other end-use products.

[0168] Other end-use products can include products in the following categories:

[0169] Semifinished products: including copper wire rods for the wire and cable industry;

[0170] Power generation: including electrical conductors, transformers, wires and cables;

[0171] Construction: including pipes, roofs and building elements;

[0172] Electronic devices: including printed circuit boards (PCBs), wiring and semiconductors;

[0173] Automotive industry: radiators, connectors and wiring;

[0174] Telecommunications: including communication networks;

[0175] Copper alloys, such as brass and bronze, are widely used in a variety of applications due to their unique properties, such as high strength, corrosion resistance and aesthetic appeal; and

[0176] Ornaments: including coins, medals and other ornaments.

[0177] The end-use products can be manufactured by any suitable method.

[0178] The method can include crushing ROM material containing copper-bearing material into fragments, agglomerating the fragments into agglomerates, and constructing a first pile and a second pile from the agglomerates.

[0179] The method can include adding additional materials (additives) to the copper-bearing material before, during or after pile formation, or adding additional materials (additives) to the leaching solution.

[0180] The additional materials (additives) can be sulfide-containing additives - such as pyrite, where the sulfide-containing additives are obtained from any suitable source, such as selected scavenger tailings from a concentrator circuit, and noting that generally the copper sulfide-containing material in the copper-bearing material contains pyrite. The material from the concentrator circuit can also contain residual flotation reagents.

[0181] The method can include selecting the amount of additional pyrite in the first pile and the second pile to reach the target temperature quickly, i.e., within ≤500 days, more typically within ≤400 days, and more typically within ≤300 days.

[0182] The additional materials (additives) can be microorganisms for oxidizing ferrous ions and oxidizing solid and soluble sulfur compounds, thereby regenerating ferric ions and acid.

[0183] The microorganisms can be any suitable microorganisms.

[0184] The microorganism can be any microorganism capable of oxidizing ferrous ions and / or sulfur compounds, and includes, but is not limited to, members of the bacterial genera Acidithiobacillus, Leptospirillum, Sulfobacillus, and Ferrimicrobium, and the archaeal genera Acidianus, Acidiplasma, Ferroplasma, Metallosphaera, and Thermoplasma.

[0185] Generally, the microorganisms are a diverse group, including microorganisms selected from mesophiles, moderate thermophiles, and thermophilic, psychrophilic, or mesophilic or thermophilic (moderate or extreme) bacteria or archaea. The microorganisms can be acidophilic bacteria or archaea. The microorganisms can be thermoacidophiles. The diverse group allows for activity across a range of operating conditions, including low pH conditions, high sulfate concentrations, and a wide temperature range such as 5 °C - 80 °C.

[0186] Additional materials (additives) can be added to the heap in any suitable manner.

[0187] For example, the method can include adding additional materials (additives) to the copper-containing material in any one or more of the following or at any one or more of the following:

[0188] (a) the location where the copper-containing material is formed in the mining operation (e.g., the collapsed material formed after a mine bench is drilled and blasted),

[0189] (b) the location where the copper-containing material is loaded onto a transport vehicle (such as a transport truck or a load-haul-dump vehicle) or a conveyor or any other transport option,

[0190] (c) when the copper-containing material is transported from the loading location in the mine to the heap, stockpile, or intermediate station, or from the stockpile or intermediate station to the heap,

[0191] (d) during the agglomeration of the copper-containing material,

[0192] (e) when the copper-containing material is added to the heap,

[0193] (f) at an intermediate station located between the loading location and the heap,

[0194] (g) at an intermediate station located between the stockpile and the heap,

[0195] (h) in a blending operation that includes blending the copper-containing material and additional pyrite together and then adding the blend to the heap,

[0196] (i) in the ore heap, and

[0197] (j) in the heap, such as in the leaching solution, or as a separate additive directly when the heap is being formed or after the heap has been formed, such as reaching the top of the heap during the heap leaching step.

[0198] The method may include, after completing the leaching of the first and second heaps, recovering the RIPIOS for storage / disposal elsewhere or for further processing as may be required.

[0199] The method may include monitoring any one or more than one heap parameter selected from among heap temperature, leaching solution temperature, leaching solution flushing rate (including optional remaining flushing cycles), aeration rate, pH of the leaching solution, E h of the leaching solution, microbial population, copper extraction rate, composition of the leaching solution, etc., and adjusting any one or more than one of the parameters to maintain the target heap conditions, and noting that the reference to "leaching solution" includes the case where the leaching solution may also be described as "enriched leaching solution", "tailings solution", and "intermediate leaching solution".

[0200] In any given case, the target heap conditions will be a function of many factors, including material mineralogy, climatic conditions, availability and cost of additives such as additional pyrite, etc.

[0201] The copper-containing material can have any copper grade, i.e., the concentration of copper in the material.

[0202] As an example, the copper-containing material can have an average copper concentration of ≤ 1.5% by weight (wt.%), typically ≤ 1.2 wt.%, and more typically ≤ 1.0 wt.%, and more typically ≤ 0.6 wt.%.

[0203] The copper-containing material can be (a) run-of-mine ("ROM") material or (b) ROM material that has undergone intermediate processing, the terms "ROM material" and "intermediate processing" being as understood herein.

[0204] The material can be ore or waste.

[0205] The term "ore" is understood herein to mean a natural rock or sediment containing one or more valuable metals that can be mined, recovered, processed, and sold for profit. It should be noted that the term "ore" is a relative term, as a material can be considered ore, i.e., profitable at one point in time, while being waste at another point in time. It should also be noted that the assessment of whether a material is "ore" (i.e., whether it is profitable) can also depend on the mine from which the material is mined and the capital and operating costs of the mine, including whether the mine is a brownfield mine or a greenfield mine.

[0206] The term "intermediate processing" relates to any type of processing of ROM material, including processing that falls under the general description of "ore dressing", including but not limited to any one or more of the following: crushing, size separation into different size fractions, separation into different grade fractions by the grade of the target base metal (e.g., the concentration of the base metal), separation by other chemical and mineralogical constituents of the ROM material (such as contaminants), separation by other properties of the ROM material, and agglomeration.

[0207] ROM material can be obtained from any mining operation in a mine.

[0208] The mining operation can be on the surface.

[0209] The mining operation can be underground.

[0210] For example, the mining operation can be drilling and blasting operations in an open-pit mine, where the ROM material is rock that forms when the mine bench is drilled and blasted and collapses into the pit, and is then transported from the pit by haul trucks or other suitable vehicles or conveyors.

[0211] As another example, the mining operation can be an operation involving the use of a continuous miner, where the ROM material is rock produced by the continuous miner.

[0212] As another example, the mining operation can be an underground mining operation, including block caving, sublevel caving, or any other suitable underground mining method, where the material is removed as a metal sulfide-containing material from an extraction site such as a drawpoint in a block caving mine and is transported to the surface by haul trucks or other suitable vehicles or conveyors.

[0213] As another example, the mining operation can be a block caving operation in an underground mine, where the ROM material is rock in a drawpoint sump at the extraction site of the block cave.

[0214] The copper-containing material can be of any suitable size for the heap.

[0215] The rock size can range from coarse to fine, depending on other operational considerations.

[0216] For example, the copper-containing material can have a rock size in the range between P80 of 500 mm and P80 of 9 mm, typically in the range between P80 of 400 mm and P80 of 30 mm, and typically in the range between P80 of 100 mm and P80 of 9 mm.

[0217] It should be noted that the size of the copper-containing material can be greater than or less than the size range described above.

[0218] The copper-containing material can be in any suitable shape, noting that the dimensional ranges described in the preceding paragraphs are based on only one dimension.

[0219] The method can include selecting a mining method to form copper-containing material in a suitable form (including size distribution and / or shape) for heap leaching.

[0220] The mining method can include separating ROM material into different size fractions of ROM material based on size, for example via a screen. The size-separated material is within the definition of ROM material.

[0221] The heap can be a separate heap.

[0222] The heaps can be arranged end-to-end or side-by-side, arranged in a row or as required according to the available space or the desired geometry.

[0223] Each heap can be a separate lift of a "single" heap.

[0224] Multiple lift heaps can also be utilized.

[0225] The heap can be of the type described in International Application PCT / AU2011 / 001144 (WO2012 / 031317) in the name of the applicant, and the disclosure in the international publication regarding the heap construction and leaching process of the heap is incorporated herein by cross-reference.

[0226] The heap can include drip heads to supply a leaching solution to each heap to avoid freezing and minimize evaporation. The drip heads can also be covered with material or any other insulating material (including a thermal film or snow) to enable operation throughout the year. The method can include providing heat from other sources to avoid freezing.

[0227] Broadly speaking, the present invention also provides a heap leaching operation for leaching copper from copper-containing material, the heap leaching operation including:

[0228] (a) A first heap leaching circuit that leaches a portion of the copper-containing material with a microbial-assisted aerated leaching using an acidic leaching solution in a first heap leaching, wherein microorganisms produce ferric ions, and wherein the ferric ions and the acid dissolve the copper in the copper sulfide-containing material in the copper-containing material and produce ferrous ions, acid, and heat, and pyrite or other iron-containing minerals in or added to the material produce ferrous ions, acid, and heat, and produce a first enriched leaching solution,

[0229] (b) A second heap leaching circuit that leaches another portion of the copper-containing material with an acidic leaching solution, where the acidic leaching solution contains at least a portion of the first enriched leaching solution from the first heap or a leaching solution generated during the processing of the first enriched leaching solution to recover copper from the first enriched leaching solution (e.g., the leaching solution can be the raffinate generated in a solvent extraction circuit for recovering copper from the enriched leaching solution), where the acid and / or iron dissolve the copper in the material, consume the excess acid, and reduce the neutralization requirement, and a second enriched leaching solution is generated, and

[0230] (c) A copper recovery circuit that recovers copper from one or both of the first enriched leaching solution and the second enriched leaching solution.

[0231] The present invention also relates to recovering copper from a copper metal recovery circuit.

[0232] The present invention also relates to end-use products made from the recovered copper.

[0233] As described above, the end-use product can be any suitable end-use product.

[0234] The applicant has recognized that the present invention is not limited to leaching copper from copper-containing materials and also extends to leaching base metals from base metal-containing materials.

[0235] Generally speaking, the present invention also provides a method for heap leaching base metals from base metal-containing materials from a mine, the method comprising:

[0236] (a) Leaching a first heap of a portion of the base metal-containing material with an acidic leaching solution, where the acid helps dissolve the base metals in the base metal sulfide materials in the base metal-containing material,

[0237] (b) Collecting a first enriched leaching solution containing base metals in solution from the first heap,

[0238] (c) Leaching a second heap of another portion of the copper-containing material with an acidic leaching solution, where the acidic leaching solution contains at least a portion of the first enriched leaching solution from the first heap or a leaching solution generated during the processing of the first enriched leaching solution to recover base metals from the first enriched leaching solution (e.g., the leaching solution can be the raffinate generated in a solvent extraction circuit for recovering base metals from the enriched leaching solution), where the acid and / or iron dissolve the base metals in the material, consume the excess acid, and reduce the neutralization requirement,

[0239] (d) Collecting a second enriched leaching solution containing base metals in solution from the second heap, and

[0240] (e) Recovering base metals from one or both of the first enriched leaching solution and the second enriched leaching solution.

[0241] Broadly speaking, the present invention also provides a heap leaching operation for leaching base metals from base metal-containing materials, the heap leaching operation comprising:

[0242] (a) A first heap leaching circuit that leaches a portion of the base metal-containing material with an acidic leaching solution and produces a first enriched leaching solution, wherein the acid aids in dissolving the base metals in the base metal sulfide-containing material in the base metal-containing material,

[0243] (b) A second heap leaching circuit that leaches another portion of the base metal-containing material with an acidic leaching solution that comprises at least a portion of the first enriched leaching solution from the first heap or a leaching solution produced during processing of the first enriched leaching solution to recover base metals from the first enriched leaching solution (e.g., the leaching solution can be a raffinate produced in a solvent extraction circuit for recovering base metals from the enriched leaching solution), wherein the acid and / or iron dissolve the base metals in the material, consume excess acid, and reduce the neutralization requirement, and produce an enriched leaching solution, and

[0244] (c) A base metal recovery circuit that recovers base metals from one or both of the first enriched leaching solution and the second enriched leaching solution.

[0245] The present invention also relates to the recovery of base metals from the base metal recovery circuit.

[0246] The present invention also relates to end use products made from the recovered base metals.

[0247] The end use products can be any suitable end use products.

[0248] The end use products can be manufactured by any suitable method. Brief Description of the Drawings

[0250] The following describes the present invention only with reference to Figure 1 by way of example, which Figure 1 is a flow chart of an embodiment of a method for heap leaching copper-containing materials according to the present invention.

[0251] Detailed Description of the Drawings

[0252] Figure 1 The embodiment of the method for heap leaching copper-containing materials according to the present invention shown in the figures leaches the agglomerates of copper-containing materials in two separate heaps 21, 23 and recovers copper from the enriched leaching solution.

[0253] In this embodiment, the copper-containing materials in the heaps 21, 23 are sourced from a mine having copper sulfide-containing materials and copper oxide-containing materials (as defined by the terms above).

[0254] The copper-containing materials in heaps 21, 23 can be sourced from run-of-mine (ROM) copper-containing materials 3 from a mine, which can be an open-pit mine and / or an underground mine, or a stockpile of mined material.

[0255] The method includes:

[0256] (a) forming a first heap 21 from an agglomerate of copper sulfide-containing material, which optionally may further include an agglomerate of copper oxide-containing material, and

[0257] (b) leaching the copper-containing materials in the first heap 21 under leaching conditions that are focused on leaching the copper sulfide-containing materials, wherein the leaching conditions are microbiologically assisted aerated leaching with an acidic leaching solution, wherein microorganisms generate ferric ions, wherein the acid and ferric ions dissolve the copper in the copper sulfide-containing materials in the copper-containing materials and generate ferrous ions, and wherein iron sulfides (such as pyrite) in the materials or added to the materials generate ferrous ions, acid, and heat, and

[0258] (c) collecting a first enriched leaching solution containing copper in solution from the first heap 21, and

[0259] (d) forming a second heap 23 from an agglomerate of copper oxide-containing material, which optionally may further include an agglomerate of copper sulfide-containing material, and

[0260] (e) leaching the copper-containing materials in the second heap 23 under leaching conditions that are focused on leaching the copper oxide-containing materials, wherein the leaching conditions include leaching with an acidic leaching solution that includes at least a portion of the first enriched leaching solution from the first heap 21, wherein the acid and ferric ions dissolve the copper in the materials, consume excess acid, and reduce the neutralization requirement, and

[0261] (f) collecting a second enriched leaching solution containing copper in solution from the second heap 23; and

[0262] (g) recovering copper from any first enriched leaching solution that has not been transferred to the second heap and recovering copper from the second enriched leaching solution.

[0263] This embodiment beneficially and advantageously processes copper-containing materials in two heaps 21, 23 in a connected heap leaching operation, wherein the leaching conditions are selected to be focused on leaching the copper sulfide-containing materials in heap 21 and the copper oxide-containing materials in heap 23.

[0264] Using concentrated leaching conditions in separate heaps 21, 23 provides the opportunity to advantageously use the first enriched leaching solution from heap 21 in heap 23 to reduce downstream acid neutralization requirements and maximize heat utilization in the heap and other advantages described below. It should be noted that in some embodiments, all of the enriched leaching solution from heap 21 is transferred to heap 23. It should be noted that in other embodiments, a portion of the enriched leaching solution from heap 21 is transferred to heap 23.

[0265] Referring to the Figure 1 , the run-of-mine (ROM) copper-containing material 3 from a mine which can be an open-pit mine and / or an underground mine or a stockpile of mined material is processed in a crushing circuit generally identified by the numeral 5, and fragments of the copper-containing material 3 are produced.

[0266] If desired, the crushing circuit 5 can include a first stage, a second stage, and a third stage. It should be noted that the equipment used in these stages can be any suitable equipment, and the present invention is not limited to the selection of a particular equipment. It should also be noted that the present invention is not limited to a three-stage crushing circuit, and the crushing circuit 5 can be any suitable number of stages.

[0267] The output 7 from the crushing circuit 5 is transferred to a size separation unit 9 and separated into an oversize fraction 11 and an agglomeration-size fraction 13 according to the fragment size. The size separation unit 9 can be any suitable unit, such as a screen. The oversize fraction 11 is returned to the crushing circuit 5. The agglomeration-size fraction 13 is transferred to an agglomeration unit 15.

[0268] The agglomeration unit 15 agglomerates the agglomeration-size fraction 13 and produces agglomerates for heaps 21, 23. The agglomeration unit 15 can be any suitable unit. Additives can be added to the agglomeration unit 15. These additives can include acids, microorganisms, etc. The agglomeration conditions, including the addition rate of the agglomeration-size fraction 13 and any additives and the residence time in the agglomeration unit 15, are selected as needed for leaching in the first heap 21 or the second heap 23, depending on which heap is suitable for the copper-containing material.

[0269] The additives will vary depending on the ROM material, i.e., whether the ROM material is a copper sulfide-containing material or a copper oxide-containing material or a mixture of these materials, as well as the nature of the gangue in the ROM material and the leaching conditions required for the ROM material.

[0270] For example, in the case of a predominantly copper sulfide-containing material, air, sulfuric acid, water, an iron-containing sulfide mineral (such as pyrite), and microorganisms are typically added to the agglomeration unit 15.

[0271] These additives can also be added at other places in the flow chart.

[0272] Microorganisms are produced in the microorganism production unit 59.

[0273] The microorganism production unit 59 includes a series of connected agitated tanks 69. As required, air, acid, and water are supplied to the tanks 69 via line 73. In addition, iron-bearing sulfide minerals (such as pyrite) in the tailings from the scavenger unit of the beneficiation plant circuit (not shown) in the mine are supplied to the tanks 69 via line 71. It should be noted that the iron-bearing sulfide minerals (such as pyrite) can be obtained from any suitable source.

[0274] The microorganisms produced in the microorganism production unit 59, usually in the form of a slurry, are added to the agglomeration unit 15 via line 61.

[0275] The microorganism production unit 59 also produces an acidic solution, which is transferred via line 53 to the first heap 21 and forms part of the leaching solution for the heap.

[0276] The agglomerates 17 from the agglomeration unit 15 are transferred to the appropriate heaps 21, 23 to form the initial lift zone or the continuous lift zone of the heap. Figure 1 There are 4 lift zones in the heap 21 shown, and a single lift zone in the heap 23. The present invention is not limited to the number of lift zones in the heaps 21, 23.

[0277] The heaps 21, 23 can be of any suitable structure and any suitable size.

[0278] For example, the heaps 21, 23 can be as described in the international application PCT / AU2011 / 001144 (WO2012 / 031317) in the name of the applicant, and the disclosure in the international publication is incorporated herein by cross-reference.

[0279] The heaps 21, 23 can have a cover to control heat transfer into and out of the heap. The cover can be made of a thermal film or any other suitable material. In addition, in cold climates, snow can serve as a cover.

[0280] The heaps 21, 23 can have an aeration system for supplying air to the heap. The aeration system can be based on natural air flow or forced air flow via line 75 to the first heap 21.

[0281] The heaps 21, 23 include a system for transferring the acidic leaching solution (in some cases the raffinate and in other cases the enriched leaching solution, with or without supplementary acid from other sources) to the top surface of the heaps 21, 23 and distributing it over the top surface of the heaps 21, 23 such that the leaching solution can flow downward through the heap and dissolve the copper in the copper-bearing material in the heaps 21, 23.

[0282] The system can be any suitable system.

[0283] Advantageously, in cold climates, the system can include drippers (not shown) to minimize the risk of freezing of the leaching solution. The drippers and the acidic leaching solution supply lines can also be covered with any suitable insulation material (including heat film and snow) to enable operation throughout the year.

[0284] The heaps 21, 23 include a system for collecting and processing the enriched leaching solution from the lower section of the heaps.

[0285] The collection system includes a series of ponds, which include a raffinate pond 27, an intermediate leaching solution ("ILS") pond 29, an enriched leaching solution ("PLS") pond 31, and an emergency pond 33.

[0286] The use of the ponds 27, 29, 31 is further described below.

[0287] The enriched leaching solution from the first heap 21 is collected from the lower section of the heap and transferred in line 25 to the ILS pond 29.

[0288] As needed, sulfuric acid, additives (such as those described above), and water are transferred in line 41 to the ILS pond 29.

[0289] Then, as needed, a portion of the enriched leaching solution is transferred from the ILS pond 29 in line 35 to the second heap 23, distributed over the top surface of the heap, and flows through the heap to leach copper.

[0290] The enriched leaching solution from the lower section of the second heap 23 is collected and transferred in line 37 to the PLS pond 31. In addition, a portion of the enriched leaching solution from the ILS pond 29 is transferred in line 39 to the PLS pond 31.

[0291] The enriched leaching solution is transferred from the PLS pond 31 in line 43 to a solvent extraction circuit, typically identified by the number 47.

[0292] Copper is stripped from the enriched leaching solution in the SX circuit 47, producing (a) copper concentrate, which is transferred in line 49 to an electrowinning circuit 51; and (b) raffinate, which is transferred in line 77 to the raffinate pond 27.

[0293] The electrowinning circuit 51 is a standard circuit for producing high-purity copper cathodes, which are sold and processed to form end-use products.

[0294] As needed, sulfuric acid, additives (such as those described above), and water are transferred to the raffinate pond 27 and mixed with the raffinate in the pond.

[0295] A portion of the raffinate is transferred from the raffinate pond 27 in line 55 to the first heap 21 and is distributed as part of the acidic leaching solution onto the upper surface of the heap 21.

[0296] As needed, another portion of the raffinate from the raffinate pond 27 is transferred via line 35 to the second heap 23 - see the dashed line connecting line 55 and line 37, where the arrow points to line 37.

[0297] In addition, as needed, a portion of the enriched leaching solution in the ILS pond 29 is transferred from line 35 to line 55 and supplied to the first heap 21 - see the dashed line connecting line 55 and line 35, where the arrow points to line 55.

[0298] The effluent stream of the raffinate is transferred from the raffinate pond 27 in line 65 to be conveyed by a raffinate treatment circuit such as the raffinate neutralization circuit 63. It should be noted that the raffinate treatment circuit is not limited to the neutralization circuit.

[0299] The neutralization circuit 63 includes two connected agitation tanks 79 (or any other appropriate number of tanks). The raffinate and limestone are supplied to the first tank. The raffinate is transferred to the second tank, and lime is also supplied to this tank. The limestone and lime neutralize the raffinate. The neutralized raffinate is transferred from the second tank to a solid / liquid separator 81 to remove the solids in the tailings stream 83.

[0300] The neutralized raffinate minus the solids is transferred in line 67 to the raffinate pond 27.

[0301] The tailings stream 83 is sent to a suitable storage facility (not shown). Then, the liquid can be recovered from this facility and reused in this circuit or other processes (including the concentrator).

[0302] As needed, makeup sulfuric acid and water are transferred in line 41 to the raffinate pond 27. This makeup solution can be obtained from other processes, mine runoff, acid mine drainage, mine water, concentrator effluents, tailings dams, or other suitable sources.

[0303] The leaching conditions in the heaps 21, 23 are controlled by any one or more of the acidic leaching solution temperature, acidic leaching solution irrigation rate (including optional use of residual rinse cycles), aeration rate, acid addition rate, acid concentration, pH of the acidic leaching solution, ratio of ferric to ferrous iron, solution composition, and addition of additives such as microorganisms and sulfide-containing additives.

[0304] As an example, the leaching conditions in the first heap 21 are controlled such that there is net heat generation in the first heap.

[0305] Specifically, the leaching conditions in the first heap 21 are controlled such that the temperature of the first enriched leaching solution when discharged from the heap is higher than a threshold temperature.

[0306] Typically, the threshold temperature is at least 20 °C, typically at least 30 °C, and more typically at least 50 °C.

[0307] Typically, the threshold temperature is selected taking into account the leaching requirements in the first heap 21 and the leaching requirements in the second heap.

[0308] Specifically, the threshold temperature is selected to provide sufficient heat from the first enriched leaching solution to maintain the required heap temperature in the second heap, especially in cases where the ability to generate heat in the second heap is limited.

[0309] In other words, the second heap 23 beneficially consumes the heat in the first enriched leaching solution of the first heap 21.

[0310] Consuming the heat of the first enriched leaching solution from the first heap 21 in the second heap provides an opportunity to effectively utilize heat in the process and reduce the temperature of the second enriched leaching solution discharged from the second heap 23 to an optimal temperature range for downstream copper recovery in the solvent extraction circuit 47. This potentially avoids the need to cool the second enriched leaching solution before it is used for downstream copper recovery. Typically, the threshold temperature is 40 °C - 50 °C.

[0311] The combination of separate heaps 21, 23 that concentrate on leaching copper sulfide-containing materials in one heap and copper oxide-containing materials in another heap also enables maximizing copper recovery from mines with economically significant reserves of copper sulfide ore materials and copper oxide materials, especially in cases where the copper oxide materials are difficult to process in the concentrator circuit.

[0312] The leaching conditions in the heap can be controlled by any one or more than one of the following options.

[0313] · Controlling the pH profile of the acidic leaching solution in the first heap 21 and the second heap 23 by monitoring and controlling the acidity of the acidic leaching solution supplied to the first heap 21 and the acidity of the first enriched leaching solution and the second enriched leaching solution from the heap.

[0314] · Controlling the precipitation reaction (e.g., jarosite) and acid-producing reaction (sulfide minerals) in the heaps 21, 23.

[0315] · Controlling heat transfer, e.g., increasing / decreasing heat loss via aeration and acidic leaching solution application rate. This also has an impact on the precipitation reaction (e.g., jarosite) and acid-producing reaction (sulfide minerals).

[0316] · Control the entry of air as needed to promote the oxidation of iron.

[0317] · Control E in piles 21, 23 h , including operating in a wide E h range during the leaching stage.

[0318] · Control the precipitation chemistry in the second pile 23 to control impurities (such as metal sulfates) - this reduces the neutralization requirements.

[0319] · Add carbonate ore to piles 21, 23 to promote bacterial growth.

[0320] · Use the mineralogy of the materials in piles 21, 23 to inform the hydrodynamic behavior in the piles.

[0321] · Recycle the acidic leaching solution between piles 21, 23 to increase the metal content, reduce water consumption / increase water efficiency, control acidity and control impurities.

[0322] Many modifications can be made to the embodiments without departing from the spirit and scope of the invention.

[0323] For example, it should be noted again that the invention is not limited to copper, but extends to other base metals in base metal-containing materials such as metal sulfide minerals and metal oxide minerals containing metals, such as nickel or zinc or cobalt.

[0324] It should also be noted that the invention extends to the recovery of rare earth elements, scandium, manganese, etc. present in base metal-containing materials.

[0325] As a further example, although the embodiments include agglomerating the crushed fragments of the ROM material and forming piles 21, 23 from the agglomerate, the invention is not limited thereto, but extends to forming piles from the ROM material, which is typically crushed to a selected fragment size.

[0326] As a further example, the invention extends to embodiments that include using sorting techniques to directly sort materials from a mine or stockpile based on, for example, whether the material is a copper sulfide-containing material or a copper oxide-containing material.

[0327] As a further example, the invention extends to embodiments that include using sorting techniques to sort copper sulfide-containing materials or copper oxide-containing materials based on grade and transferring materials above a selected threshold to one of piles 21, 23. Sorting based on mineralogy and chemical composition can also be performed.

[0328] As a further example, while the embodiments include transferring the enriched leach solution from the ILS pond 29 (which has been transferred from the heap 21 to the ILS pond 29) to the top surface of the heap 23, the invention also extends to embodiments in which the enriched leach solution from the heap 21 is processed before being transferred to the top surface of the heap 23. As an example, the enriched leach solution can be processed in the solvent extraction circuit 47 to remove copper from the enriched leach solution, and at least a portion of the raffinate produced in the circuit can be transferred to the top surface of the heap 23 as a leach solution.

Claims

1. A method for heap leaching copper from copper-containing materials from a mine, the method comprising: (a) subjecting a first heap of a portion of the copper-containing material to microbiologically assisted aerated leaching with an acidic leaching solution, wherein microorganisms produce ferric ions, wherein the acid and ferric ions dissolve copper in the copper sulfide-containing material in the copper-containing material and produce ferrous ions, and wherein pyrite or other iron-containing minerals in or added to the material produce ferrous ions, acid, and heat, (b) collecting a first enriched leaching solution containing copper in solution from the first heap, (c) leaching a second heap of another portion of the copper-containing material with an acidic leaching solution comprising at least a portion of the first enriched leaching solution from the first heap or a leaching solution produced during processing of the first enriched leaching solution to recover copper from the first enriched leaching solution, wherein the acid and ferric ions dissolve copper in the material, consume excess acid, and reduce the neutralization requirement, (d) collecting a second enriched leaching solution containing copper in solution from the second heap, and (e) recovering copper from one or both of the enriched leaching solutions from the first heap and the second heap.

2. The method according to claim 1, wherein the copper-containing material in one heap is different from the copper-containing material in the other heap.

3. The method according to claim 1, wherein the copper-containing material in the first heap is mainly a copper sulfide-containing material.

4. The method according to claim 1 or claim 3, wherein the copper-containing material in the second heap is mainly a copper oxide-containing material.

5. The method according to any one of the preceding claims, further comprising sorting the copper-containing material before transferring the copper-containing material to the first heap or the second heap and transferring the selected sorted material to one or the other of the heaps or to a waste heap.

6. The method according to claim 5, comprising sorting the material based on the suitability of the material to be leached in the first heap or the second heap.

7. The method according to claim 5 or claim 6, comprising sorting the material based on the potential of the material to generate / consume heat in the first heap or the second heap.

8. The method according to any one of the preceding claims, comprising sorting the copper-containing material that has been selected for one heap before transferring the selected sorted material to the heap or to the waste heap.

9. The method according to claim 8, comprising sorting the copper-containing material based on the copper grade of the material.

10. The method according to any one of the preceding claims, comprising controlling the leaching in the first heap or the second heap according to any one or more of the temperature of the acidic leaching solution, the flushing rate of the acidic leaching solution (including optionally using the remaining flushing cycles), the aeration rate, the acid addition rate, the acid concentration, the pH of the acidic leaching solution, the ratio of ferric iron to ferrous iron, the composition of the acidic leaching solution, and the addition of additives, such as microorganisms and sulfide-containing additives.

11. The method according to any one of the preceding claims, comprising controlling the leaching in the first heap such that the temperature of the first enriched leaching solution is the target temperature when discharged from the first heap.

12. The method according to claim 11, comprising controlling the leaching in the first heap such that the temperature of the first enriched leaching solution is higher than a threshold temperature when discharged from the first heap.

13. The method according to claim 12, wherein the threshold temperature is selected to provide sufficient heat from the first enriched leaching solution to maintain the required heap temperature in the second heap, particularly in cases where the ability to generate heat in the second heap is limited.

14. The method according to claim 11, wherein the target temperature of the first enriched leaching solution is at least 20 °C, typically at least 30 °C, and more typically at least 50 °C.

15. The method according to any one of the preceding claims, comprising controlling the leaching in the second heap such that the temperature of the second enriched leaching solution is the target temperature when discharged from the second heap.

16. The method according to claim 15, comprising controlling the leaching in the second heap such that the temperature of the second enriched leaching solution is lower than a threshold temperature when discharged from the second heap.

17. The method according to claim 16, wherein the threshold temperature is 40 °C - 50 °C.

18. The method according to any one of the preceding claims, comprising aerating the first heap by supplying air to the heap via forced aeration and / or aerating the second heap by supplying air to the heap via forced aeration.

19. The method according to any one of claims 1 - 17, comprising aerating the first heap via natural circulation of air entering the heap from the outside of the heap and / or aerating the second heap via natural circulation of air entering the heap from the outside of the heap.

20. The method according to any one of the preceding claims, comprising crushing the ROM material containing the copper-containing material into fragments, agglomerating the fragments into agglomerates, and constructing the first heap and the second heap from the agglomerates.

21. The method according to any one of the preceding claims, wherein the recovery step € comprises recovering copper from the first enriched leaching solution and / or the second enriched leaching solution by any one of the following recovery methods: (a) solvent extraction and electrowinning (SX / EW), (b) cementation onto a more reactive metal such as iron, (c) hydrogen reduction, (d) sulfidation via addition of H2S or NaHS, (e) crystallization of sulfates, and (e) direct electrowinning.

22. An end-use product made of copper recovered by any one of the recovery methods according to claim 21.

23. The end-use product according to claim 22, comprising cathodes produced in a solvent extraction and electrowinning (SX / EW) or direct electrowinning process.

24. The end-use product according to claim 22, comprising any one of billets, ingots, rods, and tubes, each of which can be sold to downstream manufacturers of other end-use products.

25. The end-use product according to claim 22, comprising products in the following categories: Semi-finished products: including copper wire rods for the wire and cable industry; Power generation: including electrical conductors, transformers, wires, and cables; Construction: including pipes, roofing, and building elements; Electronics: including printed circuit boards (PCBs), wiring, and semiconductors; Automotive industry: including radiators, connectors, and wiring; Telecommunications: including communication networks; Copper alloys, such as brass and bronze, which are widely used in a variety of applications due to their unique properties, such as high strength, corrosion resistance, and aesthetic appeal; and Decorations: including coins, medals, and other ornaments.

26. A heap leaching operation for leaching copper from copper-containing materials, the heap leaching operation comprising: (a) A first heap leaching circuit that leaches a portion of the copper-containing material in a first heap with an acidic leaching solution in a microbially assisted aerated leaching process, wherein the microorganisms produce ferric ions, and wherein the ferric ions and the acid dissolve the copper in the copper sulfide-containing material in the copper-containing material and produce ferrous ions, acid, and heat, and wherein pyrite or other iron-containing minerals in or added to the material produce ferrous ions, acid, and heat, and produce a first enriched leaching solution, (b) A second heap leaching circuit that leaches another portion of the copper-containing material with an acidic leaching solution that comprises at least a portion of the first enriched leaching solution from the first heap or a leaching solution produced during processing of the first enriched leaching solution to recover copper from the first enriched leaching solution, wherein the acid and / or iron dissolve the copper in the material, consume excess acid, and reduce the neutralization requirement, and produce a second enriched leaching solution, and (c) A copper recovery circuit that recovers copper from one or both of the first enriched leaching solution and the second enriched leaching solution.

27. A method for heap leaching base metals from base metal-containing materials, comprising: (a) Leach a first heap of a portion of the base metal-containing material with an acidic leaching solution, wherein the acid aids in dissolving the base metal in the base metal sulfide material in the base metal-containing material. (b) Collect a first enriched leaching solution containing the base metal in solution from the first heap. (c) Leach a second heap of another portion of the copper-containing material with an acidic leaching solution, the acidic leaching solution comprising at least a portion of the first enriched leaching solution from the first heap or a leaching solution generated during processing of the first enriched leaching solution to recover the base metal from the first enriched leaching solution, wherein the acid dissolves the base metal in the material, consumes excess acid, and reduces the neutralization requirement. (d) Collect a second enriched leaching solution containing the base metal in solution from the second heap, and (e) Recover copper from one or both of the enriched leaching solutions.

28. A heap leaching operation for leaching base metals from a base metal-containing material, the heap leaching operation comprising: (a) A first heap leaching circuit that leaches a portion of the base metal-containing material with an acidic leaching solution and produces a first enriched leaching solution, wherein the acid aids in dissolving the base metal in the base metal sulfide material in the base metal-containing material. (b) A second heap leaching circuit that leaches another portion of the base metal-containing material with an acidic leaching solution, the acidic leaching solution comprising at least a portion of the first enriched leaching solution from the first heap or a leaching solution generated during processing of the first enriched leaching solution to recover the base metal from the first enriched leaching solution, wherein the acid and / or iron dissolves the base metal in the material, consumes excess acid, and reduces the neutralization requirement, and produces a second enriched leaching solution, and (c) A base metal recovery circuit that recovers base metals from one or both of the first enriched leaching solution and the second enriched leaching solution.

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