Method of metal recovery

Abstract

This invention relates to a method for the recovery of metal from a material comprising: contacting a material with a first reagent comprising a thiocarbonyl group and a second reagent under various conditions. The metal may be a base metal, a precious metal, or a combination thereof. The conditions include, but are not limited to, recovery in the presence of a microbe; optimal material size and / or shape; geolocation parameters; elemental sulfur; added pyrite; or a combination thereof.

Description

PATENT APPLICATIONMETHOD OF METAL RECOVERYCROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to and the benefit of the filing of U.S. Provisional Patent Application No. 63 / 659,292, entitled "METHOD OF METAL RECOVERY", filed on June 12, 2024, and the specification thereof is incorporated herein by reference.BACKGROUND OF THE INVENTIONField of the Invention (Technical Field):

[0002] The present invention relates to the recovery of a metal with a reagent comprising a thiocarbonyl group.Description of Related Art:

[0003] Chalcopyrite accounts for nearly 70% of known copper reserves.Hydrometallurgical processing accounts for 20% of copper produced worldwide but it is not currently widely used for chalcopyrite ores. Rather, pyrometallurgical methods are used for concentrates of these ores. Aqueous processing of minerals presents several advantages over pyrometallurgical approaches, particularly when dealing with complex and low-grade ores. The main disadvantage of hydrometallurgical processes, when applied to chalcopyrite and some other sulfide ores, is the low extraction rates that are observed due to the formation of a passivation layer that prevents copper from being extracted at reasonable rates. It is desirable to develop processes where passivation is not an issue and high copper extractions can be achieved in timescales that are of industrial interest. Previous methods have been focused on the change of solute composition, particle size as well as external environment such as temperature and pressure to enhance the copper extraction. This invention provides a new platform for the adaptation of methods using areagent comprising a thiocarbonyl to recover a metal. The invention is useful not only for chalcopyrite and copper ores or materials but for other base metals.BRIEF SUMMARY OF THE INVENTION

[0004] Embodiments of the present invention relate to a method of recovering a base metal from a material comprising the base metal, the method comprising: contacting the material under acidic conditions with a reagent comprising a thiocarbonyl functional group, a microbe, and a growth agent; and recovering the base metal from the material comprising the base metal. In another embodiment, the method further comprises generating sulfate. In another embodiment, the method further comprises maintaining a sulfate below a threshold concentration. In another embodiment, wherein the threshold concentration is about 200 g / L to about 100 g / L. In another embodiment, the growth agent comprises a yeast extract. In another embodiment, the growth agent comprises a bacterium. In another embodiment, the growth agent comprises a plasmid. In another embodiment, the growth agent comprises an antibiotic. In another embodiment, the growth agent comprises a growth factor.

[0005] In another embodiment, the microbe is an oxidizing microbe. In another embodiment, the method further comprises oxidizing a sulfur compound with the microbe. In another embodiment, the microbe is a bacteria. In another embodiment, the method further comprises contacting the material with an oxidant.

[0006] In another embodiment, the method further comprises contacting the material with a halide. In another embodiment, the method further comprises contacting the material with carbonaceous matter. In another embodiment, the method further comprises contacting the material with a wetting agent. In another embodiment, the method further comprises contacting the material with a cosolvent. In another embodiment, the reagent comprising a thiocarbonyl functional group is at a concentration of about 0.001 mM to about 100 mM. In another embodiment, the method further comprises recovering the base metal by solvent extraction and electrowinning. In another embodiment, the reagent does not complex / precipitate with the base metal.

[0007] Embodiments of the present invention also relate to a method of recovering a base metal from a material comprising the base metal, the method comprising: obtaining mineral composition data from a localized area; identifying a location of a recoverable basemetal-bearing material using data from the material from the localized area; distributing a solution comprising a reagent comprising a thiocarbonyl functional group to the location of the recoverable base metal-bearing material; and recovering the base metal from the solution. In another embodiment, the mineral composition data comprises data related to a passivated mineral. In another embodiment, obtaining mineral composition data comprises using an analytical process. In another embodiment, the analytical process comprises a test for a metal concentration. In another embodiment, the analytical process comprises a test for Eh. In another embodiment, the analytical process comprises a test for pH.

[0008] In another embodiment, identifying a location of a recoverable base metalbearing material comprises use of a heap ore map. In another embodiment, the method further comprises determining x,y,z coordinates for the identified location of a material. In another embodiment, distributing a solution comprising a reagent comprising a thiocarbonyl functional group comprises use of an acidic solution metering system. In another embodiment, the acidic solution metering system comprises a plurality of acidic solution regulating modules. In another embodiment, the acidic solution metering system comprises a meter configured to detect a pressure or a flow rate of the acidic solution. In another embodiment, the method further comprises at least partially disposing a subsurface acidic solution distribution system into, or in proximity to, the identified location.

[0009] In another embodiment, the method further comprises contacting the material with an oxidant. In another embodiment, the method further comprises contacting the material with a halide. In another embodiment, the method further comprises contacting the material with carbonaceous matter. In another embodiment, the method further comprises contacting the material with a wetting agent. In another embodiment, the method further comprises contacting the material with a cosolvent. In another embodiment, the reagent comprising a thiocarbonyl functional group is at a concentration of about 0.001 mM to about 100 mM. In another embodiment, the method further comprises recovering the base metal by solvent extraction and electrowinning. In another embodiment, the reagent does not complex / precipitate with the base metal.

[0010] Embodiments of the present invention also relate to a method of recovering zinc and copper from a material comprising zinc and copper, the method comprising: contacting the material under acidic conditions with a reagent comprising a thiocarbonyl functional group; and recovering zinc and copper from the material. In another embodiment, the recovering of the zinc and copper is simultaneous. In anotherembodiment, the recovering of the zinc and copper is sequential. In another embodiment, the method further comprises contacting the material with an oxidant. In another embodiment, the oxidant comprises ferric sulfate. In another embodiment, the acidic conditions comprise an acidic solution. In another embodiment, the acidic solution comprises sulfuric acid.

[0011] In another embodiment, the method further comprises contacting the material with a halide. In another embodiment, the halide comprises chloride. In another embodiment, the halide comprises iodide. In another embodiment, the halide comprises bromide.

[0012] In another embodiment, the reagent comprising a thiocarbonyl functional group comprises thiourea. In another embodiment, the reagent comprising a thiocarbonyl functional group comprises ethylene thiourea. In another embodiment, the reagent comprising a thiocarbonyl functional group comprises thiosemicarbazide.

[0013] In another embodiment, the method further comprises contacting the material with carbonaceous matter. In another embodiment, the method further comprises contacting the material with a wetting agent. In another embodiment, the method further comprises contacting the material with a cosolvent. In another embodiment, the reagent comprising a thiocarbonyl functional group is at a concentration of about 0.001 mM to about 100 mM. In another embodiment, the method further comprises recovering the base metal by solvent extraction and electrowinning. In another embodiment, the reagent does not complex / precipitate with the base metal.

[0014] Embodiments of the present invention also relate to A method of recovering a base metal from a material comprising the base metal, the method comprising: contacting the material with an acidic solution comprising a reagent comprising a thiocarbonyl functional group, elemental sulfur, and an acid to produce a pregnant leach solution comprising sulfate and the base metal; and recovering the base metal from the pregnant leach solution. In another embodiment, the elemental sulfur is added. In another embodiment, the elemental sulfur is a byproduct of a sulfidic material. In another embodiment, the elemental sulfur is endogenous to the material. In another embodiment, the elemental sulfur accelerates the production of sulfate.

[0015] In another embodiment, the method further comprises agglomerating the material. In another embodiment, the method further comprises agglomerating the materialwith sulfidic waste. In another embodiment, the initial sulfate concentration in the material is 0.001 g / L to about 20 g / L.

[0016] In another embodiment, the acidic solution comprises a sulfide-containing additive. In another embodiment, the material comprises pyrite. In another embodiment, the acid is sulfuric acid. In another embodiment, the method further comprises controlling the sulfate concentration.

[0017] In another embodiment, the method further comprises contacting the material with an oxidant. In another embodiment, the method further comprises contacting the material with a halide. In another embodiment, the method further comprises contacting the material with carbonaceous matter. In another embodiment, the method further comprises contacting the material with a wetting agent. In another embodiment, the method further comprises contacting the material with a cosolvent. In another embodiment, the reagent comprising a thiocarbonyl functional group is at a concentration of about 0.001 mM to about 100 mM. In another embodiment, the method further comprises recovering the base metal by solvent extraction and electrowinning. In another embodiment, the reagent does not complex / precipitate with the base metal.

[0018] Embodiments of the present invention also relate to a method of recovering a base metal from a material comprising the base metal, the method comprising: contacting the material under acidic conditions with a reagent comprising a thiocarbonyl functional group and added pyrite; and recovering the base metal from the material comprising the base metal. In another embodiment, the pyrite is a solid. In another embodiment, the pyrite is part of a solution. In another embodiment, the method further comprises agglomerating the pyrite with the material.

[0019] In another embodiment, the pyrite is 0.1 wt% to about 25 wt% of the mass of the agglomerate. In another embodiment, the pyrite is about 0.1 wt% of the mass of the agglomerate. In another embodiment, the pyrite is 1 wt% to about 20 wt% of the mass of the agglomerate. In another embodiment, the pyrite is 10 wt% to about 15 wt% of the mass of the agglomerate. In another embodiment, the pyrite comprises a particle size of about a P80 of 1 mm. In another embodiment, the pyrite comprises a particle size of less than 1 mm. In another embodiment, the pyrite comprises a particle size of less than 250 pm. In another embodiment, the pyrite comprises a particle size of about a p80 of 250 pm.

[0020] In another embodiment, the method further comprises contacting the material with an oxidant. In another embodiment, the method further comprises contacting the material with a halide. In another embodiment, the method further comprises contacting the material with carbonaceous matter. In another embodiment, the method further comprises contacting the material with a wetting agent. In another embodiment, the method further comprises contacting the material with a cosolvent. In another embodiment, the reagent comprising a thiocarbonyl functional group is at a concentration of about 0.001 mM to about 100 mM. In another embodiment, the method further comprises recovering the base metal by solvent extraction and electrowinning. In another embodiment, the reagent does not complex / precipitate with the base metal.

[0021] Embodiments of the present invention also relate to a method of repassivating a material comprising a base metal sulfide that has been de-passivated by contact with a reagent comprising a thiocarbonyl functional group, the method comprising removing the reagent comprising a thiocarbonyl functional group from the material to allow formation of a passivation layer on the material.

[0022] Embodiments of the present invention also relate to a method of reversibly de-passivating a material comprising a base-metal sulfide, the method comprising: contacting the material with an acidic solution comprising a reagent comprising a thiocarbonyl functional group to remove a passivation layer on the material; and removing the reagent comprising a thiocarbonyl function group from the material to allow formation of a further passivation layer on the material. In another embodiment, the method further comprises contacting the material with an acidic solution comprising a reagent comprising a thiocarbonyl functional group to remove the further passivation layer from the material.

[0023] Embodiments of the present invention also relate to a method of obtaining a base metal, the method comprising recovering a base metal from a material that has been re-passivated according to the method of claim 101 or 102. In another embodiment, recovering the base metal from the material comprises: contacting the material with an acidic solution comprising a reagent comprising a thiocarbonyl functional group to produce a pregnant leach solution comprising the base metal; recovering the base metal from the pregnant leach solution.

[0024] In another embodiment, the method further comprises an additional chemical substance. In another embodiment, the additional chemical substance is a byproduct. In another embodiment, the additional chemical substance is a reaction product. In another embodiment, the additional chemical substance comprises formamidine disulfide. In another embodiment, the additional chemical substance comprises elemental sulfur.

[0025] In another embodiment, the method further comprises recirculating the additional chemical substance through a raffinate pond. In another embodiment, the method further comprises routing the reagent comprising the thiocarbonyl and / or the additional chemical substance to a solvent extraction circuit. In another embodiment, the method further comprises separating the reagent comprising the thiocarbonyl and / or the additional chemical substance out of the acidic solution.

[0026] In another embodiment, the reagent comprising the thiocarbonyl functional group disrupts the passivation layer. In another embodiment, the reagent comprising the thiocarbonyl reacts with a base metal sulfide after disrupting the passivation layer. In another embodiment, the reagent comprising the thiocarbonyl functional group allows the extraction of a base metal from a base metal sulfide.

[0027] In another embodiment, the method further comprises contacting the material with an oxidant. In another embodiment, the method further comprises contacting the material with a halide. In another embodiment, the method further comprises contacting the material with carbonaceous matter. In another embodiment, the method further comprises contacting the material with a wetting agent. In another embodiment, the method further comprises contacting the material with a cosolvent. In another embodiment, the reagent comprising a thiocarbonyl functional group is at a concentration of about 0.002 mM to about 100 mM. In another embodiment, the method further comprises recovering the base metal by solvent extraction and electrowinning. In another embodiment, the reagent does not complex / precipitate with the base metal.

[0028] Embodiments of the present invention also relate to a method of recovering a base metal from a material comprising the base metal, the method comprising: forming the material into particles comprising a size and / or shape optimal for base metal recovery from the material under acidic conditions with a reagent comprising a thiocarbonyl functional group; contacting the material under acidic conditions with a reagent comprisinga thiocarbonyl functional group; and recovering the base metal from the material comprising the base metal. In another embodiment, forming the material into particles comprises ablating the material. In another embodiment, ablating the material comprises contacting a first portion of material against a second portion of material.

[0029] In another embodiment, forming the material into particles comprises grinding. In another embodiment, grinding comprises use of a semi-autogenous grinding mill. In another embodiment, the method further comprises ball mill grinding. In another embodiment, the method further comprises rod mill grinding. In another embodiment, forming the material into particles comprises crushing. In another embodiment, forming the material into particles comprises milling. In another embodiment, forming the material into particles comprises comminuting.

[0030] In another embodiment, the method further comprises forming the material into particles in the presence of copper powder. In another embodiment, the method further comprises selectively removing particles not comprising the base metal from particles comprising the base metal.

[0031] In another embodiment, the method further comprises contacting the material with an oxidant. In another embodiment, the method further comprises contacting the material with a halide. In another embodiment, the method further comprises contacting the material with carbonaceous matter. In another embodiment, the method further comprises contacting the material with a wetting agent. In another embodiment, the method further comprises contacting the material with a cosolvent. In another embodiment, the reagent comprising a thiocarbonyl functional group is at a concentration of about 0.001 mM to about 100 mM. In another embodiment, the method further comprises recovering the base metal by solvent extraction and electrowinning. In another embodiment, the reagent does not complex / precipitate with the base metal.

[0032] Further scope of applicability of the present invention will be set forth in part in the detailed description to follow, taken in conjunction with the accompanying drawings, and in part will become apparent to those skilled in the art upon examination of the following, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and attained by means of the instrumentalities and combinations particularly pointed out in the detailed description of the invention.BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

[0033] The accompanying drawings, which are incorporated into and form a part of the specification, illustrate one or more embodiments of the present invention and, together with the description, serve to explain the principles of the invention. The drawings are only for the purpose of illustrating one or more embodiments of the invention and are not to be construed as limiting the invention. In the drawings:

[0034] Fig. 1 is a graph showing zinc extraction from synthetic raffinate, according to an embodiment of the invention;

[0035] Fig. 2 is a nuclear magnetic resonance spectra showing zinc extraction from synthetic raffinate, according to an embodiment of the invention;

[0036] Fig. 3 is a graph showing the open circuit potential vs. a silver and silver chloride electrode for fresh chalcopyrite in raffinate, according to an embodiment of the invention;

[0037] Fig. 4 is a graph showing the open circuit potential vs. a silver and silver chloride electrode for passivated chalcopyrite in raffinate, according to an embodiment of the invention;

[0038] Fig. 5 is a graph showing the open circuit potential vs. a silver and silver chloride electrode for chalcopyrite treated with a reagent comprising a thiocarbonyl functional group in raffinate, according to an embodiment of the invention;

[0039] Fig. 6 is a graph showing the open circuit potential vs. a silver and silver chloride electrode for re-passivated chalcopyrite in raffinate, according to an embodiment of the invention;

[0040] Fig. 7 is a diagram showing an equivalent circuit for the modeling of electrochemical impedance spectroscopy (EIS) data and the calculation of charge transfer resistance (RCT), according to an embodiment of the invention;

[0041] Fig. 8 is a graph showing the RCT at 311 Ohms (Q) for freshly polished chalcopyrite, according to an embodiment of the invention;

[0042] Fig. 9 is a graph showing the RCT at 594 (Q) for passivated chalcopyrite, according to an embodiment of the invention;

[0043] Fig. 10 is a graph showing the RCTat 477 (Q) for chalcopyrite treated with a reagent comprising a thiocarbonyl functional group, according to an embodiment of the invention;

[0044] Fig. 11 is a graph showing the RCT at 560 (Q) for re-passivated chalcopyrite, according to an embodiment of the invention; and

[0045] Fig. 12 is a table showing a summary of OCP and RCTdata obtained through the current tests using raffinate and synthetic raffinate, according to an embodiment of the invention.DETAILED DESCRIPTION OF THE INVENTION

[0046] This invention relates to a method for the recovery of a metal from a material comprising: contacting a material with a reagent comprising a thiocarbonyl group under various conditions. The metal may be a base metal, a precious metal, or a combination thereof. The conditions include, but are not limited to, recovery in the presence of a microbe; optimal material size and / or shape; geolocation parameters; elemental sulfur; added pyrite; or a combination thereof. The reagent comprising a thiocarbonyl group by reversibly de-passivate a passivated material.

[0047] The metal may be a base metal (including zinc), a precious metal, or a combination thereof. The second reagent may include, but is not limited to, an oxidant, a halide, carbonaceous matter, a wetting agent, a cosolvent, or a combination thereof. The condition may comprise acid conditions.

[0048] The term “metal” as used herein means any suitable metal, but not limited to, copper, nickel, zinc, silver, gold, germanium, lead, arsenic, antimony, chromium, molybdenum, rhenium, tungsten, iron, ruthenium, osmium, cobalt, rhodium, iridium, palladium, platinum, uranium, a rare earth metal, or a combination thereof. The term “metal” encompasses the term “base metal”.

[0049] The term “base metal” as used herein means any suitable metal or combination thereof that does not comprise a precious metal (e.g., gold or platinum). Suitable base metals may include, but are not limited to, copper, nickel, iron, aluminum, lead, zinc, tin, tungsten (also sometimes referred to as wolfram), molybdenum, tantalum, magnesium, cobalt, bismuth, cadmium, titanium, zirconium, antimony, manganese, beryllium, chromium, germanium, vanadium, gallium, hafnium, indium, niobium (also sometimes referred to as columbium), rhenium, thallium, or a combination thereof. The material may comprise a sulfide ore, a copper sulfide, a nickel sulfide, a cadmium sulfide, a sulfide ore comprising any of the above listed base metal sulfides or sulfide concentrates of any of the above minerals, or a combination thereof. The copper sulfide may be a primary copper sulfide (e.g., chalcopyrite, bornite, enargite or a combination thereof), a secondary copper sulfide (e.g., covellite, chalcocite or a combination thereof), or a combination thereof. The copper sulfide may comprise a primary copper sulfide, a secondary copper sulfide, or a combination thereof. The copper sulfide may comprise chalcopyrite, bornite, enargite, covellite, chalcocite, a copper sulfide of the formula CuxSywherein the x:y ratio is between 1 and 2, or a combination thereof. The copper sulfide of the formula CuxSywherein the x:y ratio is between 1 and 2 may comprise chalcocite, djurleite, digenite, or a combination thereof. The nickel sulfide may comprise pentlandite, violarite, or a combination thereof. The cadmium sulfide may comprise greenockite. Base metal sulfides other than copper sulfide, nickel sulfide, and / or cadmium sulfide are well known to the person skilled in the art.

[0050] The term “precious metal” as used herein means gold, silver, and / or platinum.

[0051] The term “recovery” as used herein means a process used to liberate, extract, free, or remove metal or metals from a material.

[0052] The terms “reagent” and “reagent comprising a thiocarbonyl” are used interchangeably throughout the specification and drawings.

[0053] The term “reagent comprising a thiocarbonyl” as used herein means an organosulfur compound comprising a C=S functional group that may also be known in the art as a thione or thioketone. The reagent comprising a thiocarbonyl may be any suitable reagent comprising a thiocarbonyl. For example, a suitable reagent comprising a thiocarbonyl may feature a C=S functional group having a sulfur bearing a partial negativecharge, bearing a negative electrostatic potential surface and having an empty n - antibonding orbital as its lowest unoccupied molecular orbital (LUMO), provided that the reagent comprising a thiocarbonyl is at least partially soluble in water and preferably does not significantly complex with a base metal and / or (if present) the oxidizing agent to form insoluble precipitates. Certain reagents comprising a thiocarbonyl may oxidize to form the corresponding dimer. For example, thiourea, in the presence of a suitable oxidant such as ferric sulfate, is capable of oxidizing to form the dimer formamidine disulfide (FDS). An equilibrium exists between FDS and thiourea in a ferric sulfate solution such that, for example, an acidic solution prepared with a dimer of a reagent comprising a thiocarbonyl (e.g., FDS) will provide a reagent comprising a thiocarbonyl for contacting the material. Accordingly, the reagent may comprise a thiocarbonyl added to the process in the form of the corresponding dimer. The reagent comprising a thiocarbonyl may be added to the method in monomeric form (i.e., in the form of the reagent comprising a thiocarbonyl).

[0054] The term “optimal” as used herein means within 5% of an idealized, perfect, or preferred outcome, value, and / or characteristic.

[0055] The term “growth agent” as used herein means a non-nutrient used to enhance, improve, and / or accelerate the growth of a microbe including, but not limited to, blood serum, a growth factor, a protein, a phage, a gas, a plasmid, a bacterium, an antibiotic, a probiotic, carbon dioxide, yeast extract, or a combination thereof.

[0056] The term “simultaneous" as used herein means a single step process, e.g., with a single reaction, extraction, or recovery process. A plurality of base metals may be extracted at the same time in a simultaneous process.

[0057] The term “sequential” as used herein means at least a two-step process such that a first reaction, extraction, or recovery process occurs, followed by a second reaction, extraction, or recovery. The extraction of a first base metal from a material followed by the extraction of a second base metal from a material may occur in a sequential process.

[0058] Turning now to the figures, Fig. 1 shows zinc extraction from synthetic raffinate. A greater percentage of zinc was extracted with 2 mM thiourea (Tu) and 1 mM formamidine disulfide (FDS).

[0059] Fig. 2 shows a nuclear magnetic resonance spectra of zinc extraction from synthetic raffinate. Extracted zinc from a chalcopyrite sample treated with a reagent comprising a thiocarbonyl functional group (experimental pattern) has the same peaks as control zinc (zinc sphalerite). The overlap of the extracted zinc and control peaks confirms that zinc was extracted from chalcopyrite treated with a reagent comprising a thiocarbonyl functional group.

[0060] Fig. 3 shows the open circuit potential vs. a silver and silver chloride electrode for fresh chalcopyrite in raffinate. The fresh chalcopyrite has initial OCP value 2 of 0.44 volts (V).

[0061] Fig. 4 shows the open circuit potential vs. a silver and silver chloride electrode for passivated chalcopyrite in raffinate. The passivated chalcopyrite has OCP value 4 of 0.50 V.

[0062] Fig. 5 shows the open circuit potential vs. a silver and silver chloride electrode for chalcopyrite treated with a reagent comprising a thiocarbonyl functional group in raffinate. The treated chalcopyrite has OCP value 6 of 0.48 V.

[0063] Fig. 6 shows the open circuit potential vs. a silver and silver chloride electrode for re-passivated chalcopyrite in raffinate. The re-passivated chalcopyrite has OCP value 8 of 0.50 V.

[0064] Fig. 7 shows an equivalent circuit for the modeling of electrochemical impedance spectroscopy (EIS) data and the calculation of charge transfer resistance (RCT)- RCT is used to evaluate the reactivity (or “passiveness”) of the mineral surface in contact with electrolyte.

[0065] Fig. 8 shows the RCTat 311 Ohms (Q) for freshly polished chalcopyrite.

[0066] Fig. 9 shows the RCT at 594 (Q) for passivated chalcopyrite.

[0067] Fig. 10 shows the RCT at 477 (Q) for chalcopyrite treated with a reagent comprising a thiocarbonyl functional group.

[0068] Fig. 11 shows the RCT at 560 (Q) for re-passivated chalcopyrite.

[0069] Fig. 12 shows a table showing a summary of OCP and RCT data obtained through the current tests using raffinate and synthetic raffinate.

[0070] With respect to Fig. 3 to Fig. 11 , the figures show that treatment with a reagent comprising a thiocarbonyl functional group dissolves the passivation layer formed during bioleaching thereby facilitating the release of copper into the aqueous phase. Removal of the reagent comprising a thiocarbonyl functional group results in the reformation of the passivation layer. Figs. 3 to 6 show electrochemical tests quantifying the degree of passivation of chalcopyrite mineral electrodes under different conditions.

[0071] Initial OCP and EIS measurements are shown in Figs. 3 and 8 with unreacted (fresh) mineral surface. Figs. 3 and 8 show an OCP and RCT, respectively, representing the electrochemical behavior of the fresh mineral surface prior to and after passive film formation. Figs. 4 and 9 show an OCP and RCT, respectively, representing the electrochemical behavior of the passivated mineral. The passivated electrode is placed in raffinate containing 50 ppm of a reagent comprising a thiocarbonyl functional group. The reagent comprising the thiocarbonyl functional group is shown to reverse the passivation of chalcopyrite. Figs. 5 and 10 show an OCP and RCT, respectively, representing the electrochemical behavior of the mineral treated with a reagent comprising a thiocarbonyl functional group. Figs. 5 and 11 show an OCP and RCT, respectively, representing the characteristics of the re-passivated mineral surface after removal of the reagent comprising the thiocarbonyl functional group.

[0072] Immersion of the freshly polished chalcopyrite electrode into raffinate results in an increase in open circuit potential (OCP) from 0.44 V to 0.50 V versus Ag / AgCI, indicating the occurrence of passivation. This rise in OCP reflects the formation of a surface layer that impedes electron transfer. The elevated OCP remained unchanged, confirming that the shift in potential is due to a stable chemical transformation— rather than a transient phenomenon such as surface adsorption — thereby verifying the formation of a chemically stable passivation layer.

[0073] After treatment with a reagent comprising a thiocarbonyl functional group and rinsing, the electrode is reintroduced into the original raffinate as shown in Fig. 5. The initial OCP of 0.48 V is lower than the passivated condition (0.50 V) but still higher than that of the fresh, unreacted surface (0.44 V). After 26 hours of immersion, the OCP gradually returns to 0.50 V, indicating re-establishment of the passivation layer. This re-passivated state is stable as its OCP remains unchanged, as shown in Fig. 4. Thus, the reagent comprising the thiocarbonyl functional group de-passivates chalcopyrite surfaces, but in theabsence of the reagent comprising the thiocarbonyl functional group, the mineral reverts to a passivated state.

[0074] With respect to Fig. 7 to Fig. 12, EIS tests are shown with 10 mV root mean squared (RMS) and test frequency ranging from 10K Hz to 1 Hz. The results are fitted using a simple Randles circuit shown in Fig. 7, with Rs representing solution resistance, CPE for capacitive behavior, RCTrepresenting the charge transfer resistance and W representing the typical Warburg element for diffusion process.

[0075] All measurements shown in Figs. 8 to 11 (except during treatment) are in the same electrolyte. Therefore, differences in charge transfer resistance (RCT) are directly attributable to changes in the surface reactivity of the chalcopyrite electrode.

[0076] Upon immersion in raffinate, the RCT increases from 311 O (freshly polished state) to 596 Q, representing a 91.6% increase. This rise confirms the formation of a stable, passivating surface layer that hinders electron transfer (Figs. 8 and 9). Following treatment with the reagent comprising the thiocarbonyl group, the RCT decreases to 477 O (Fig. 10), indicating that the passivation behavior has been partially reversed and that the surface has become more electrochemically active.

[0077] Subsequent re-immersion in raffinate without the reagent comprising the thiocarbonyl functional group shows an increase in RCT to 560 O. While this value remains lower than that of the initially passivated surface, it is higher than both the freshly polished and treated states. Figs. 3 to 12 show that the raffinate induces passivation of chalcopyrite, as evidenced by increases in both open circuit potential (OCP) and charge transfer resistance (RCT). The addition of the reagent comprising the thiocarbonyl functional group to raffinate disrupts the passivated surface layer and increases the electrochemical reactivity of chalcopyrite. Removal of the reagent comprising the thiocarbonyl functional group from the raffinate leads to re-passivation of the chalcopyrite surface.

[0078] The method may comprise contacting a microorganism with a bacterial agent. The bacterial agent may be used at any step of the method. The method may comprise contacting a material, bacteria, or a reagent, e.g., a reagent comprising a thiocarbonyl, with a growth agent. The growth agent may affect, e.g., increase, decrease, and / or stabilize the growth of a bacterium. The growth agent may comprise blood serum, a sugar, a lipid, a carbohydrate, a growth factor, a rock salt, a phage, a gas, a plasmid, abacterium, an antibiotic, a probiotic, carbon dioxide, yeast extracts, or a combination thereof.

[0079] The method may comprise modifying the concentration of ferrous ions in an acidic solution with a high concentration of sulfate. The concentration of ferrous ions may be modified by changing solution pH and / or temperature of the acidic solution. Oxygen may influence an operating parameter for metal extraction including, but not limited to, oxidation rate of the reagent comprising a thiocarbonyl, a second reagent, temperature, microbial activity and population, or a combination thereof. For example, increasing air and consequently oxygen supply into a heap increases microbial activity. Increasing microbial activity in turn increases the temperature of the heap, oxidation of ferrous ions into ferric ions, and oxidation of sulfur compounds into sulfuric acid.

[0080] The method may comprise controlling the sulfate concentration in an acidic solution comprising a reagent comprising a thiocarbonyl with or without the presence of microbes. The acidic solution may be contacted with a material comprising a base metal sulfide to extract a base metal from the base metal sulfide in the material. The method may comprise aerating the material and / or the acidic solution with air, flow of oxygen, other gas, or a combination thereof. The aeration may affect the sulfate concentration in the acidic solution a heap comprising the material. The method may comprise contacting the reagent comprising a thiocarbonyl and / or the second reagent with an agglomeration unit at, or close to, an inlet of an agglomeration unit. The method may comprise forming an agglomerate a short distance along the length of the unit, e.g., less than about 40% of the length of the agglomeration unit as measured from an inlet.

[0081] The method may comprise maintaining the temperature of the material or acidic solution above the temperature that mesophilic microorganisms are active, which may be at least about 45° C. The method may comprise maintaining the temperature of the material or acidic solution above the temperature that mesophilic microorganisms that are active, which may be at least about 20 °C to about 40 °C. The method may comprise maintaining the temperature of the material or acidic solution from at least about 60 °C to about 85 °C.

[0082] The method may comprise microbial assisted leaching of a base metal sulfide and sulfidic material comprising a base metal. The method may comprise: contacting an acidic solution comprising a reagent comprising a thiocarbonyl and a sulfatewith a material comprising base metal sulfides and sulfidic material comprising a base metal; flowing the acidic solution through a heap containing the material; and extracting a base metal. The method may also comprise collecting acidic solution; processing the collected acidic solution; and recovering the base metal from the acidic solution. The recovered acidic solution may comprise the material; an agglomerate of the material; a microbe; or a combination thereof. The method may comprise controlling a sulfate concentration in the acidic solution so that the sulfate concentration does not exceed a threshold concentration.

[0083] The method may comprise microbial-assisted extraction of a base metal from a material comprising base metal sulfides and sulfidic material. Microbial-assisted extraction may occur with or without intermediate processing and in the presence of high, e.g., 60 g / L, sulfate concentrations in acidic solution up to a threshold concentration. The method may comprise regenerating ferric ions and acid. Ferric ions and acid may be generated by thermophilic microorganisms in the presence of a high sulfate concentration. Ferric ions and acid generation may facilitate extraction metal from a material.

[0084] The method may comprise controlling the sulfate concentration in an acidic solution. The sulfate concentration may not exceed a threshold sulfate concentration in the acidic solution comprising a reagent comprising a thiocarbonyl. Controlling the sulfate concentration may be achieved by any process including, but not limited to, precipitation, dilution, chemical neutralization, electrochemical neutralization, solution bleeding, physical separation techniques including nanofiltration, or a combination thereof. The method may comprise monitoring the sulfate concentration in the acidic solution comprising a reagent comprising a thiocarbonyl.

[0085] The method may comprise indirectly controlling the sulfate concentration. The sulfate concentration may be indirectly controlled by controlling a parameter other than sulfate that influences the sulfate generation rate such as a parameter that causes a known change to the sulfate concentration. The parameter may include, but is not limited to, controlling the aeration rate of the material. The aeration rate may be set based on a predetermined oxygen use of the material, which in turn may be based on the composition of the material.

[0086] The material may comprise a base metal (e.g., a base metal sulfide ore) and may comprise an iron-oxidizing bacteria. The acidic solution may further comprise ironoxidizing bacteria. The iron-oxidizing bacteria may be any suitable iron-oxidizing bacteriaor combination (consortium) thereof, the selection of which may be natural or can be made by a person skilled in the art. The iron-oxidizing bacteria may comprise, but not be limited to, Acidithiobacilos ferrooxidans.

[0087] The method may comprise: microbial-assisted extraction of a material comprising a base metal sulfide and sulfidic material comprising a base metal with high sulfate concentrations in the acidic solution comprising a reagent comprising a thiocarbonyl; and contacting a microbe (also known as microorganisms, bacteria or archaea) with a material comprising a base metal sulfide and sulfidic material comprising a base metal.

[0088] A microbe, e.g., acidophilic bacteria and archaea, may regenerate ferric ions and acid through biological oxidation of ferrous ions and sulfur compounds including, but not limited to, pyrite and elemental sulfur. The sulfur compounds may be derived from oxidation of a sulfide. The sulfur compounds may comprise an inorganic compound including, but not limited to, thiosulfate, polythionates, polysulfides, or a combination thereof. The sulfur compounds may comprise an organic compound including, but not limited to, compounds such as thiourea, thiocarbamide, other thiocarbamides, or a combination thereof.

[0089] The threshold sulfate concentration may be up to 200 g / L, about 200 g / L to about 100 g / L, about 190 g / L to about 110 g / L, about 180 g / L to about 120 g / L, about 170 g / L to about 130 g / L, about 160 g / L to about 120 g / L, about 150 g / L to about 130 g / L, or about 200 g / L. The sulfate concentration may be may be up to 200 g / L, about 200 g / L to about 100 g / L, about 190 g / L to about 110 g / L, about 180 g / L to about 120 g / L, about 170 g / L to about 130 g / L, about 160 g / L to about 120 g / L, about 150 g / L to about 130 g / L, or about 200 g / L in an acidic solution contacted with a material.

[0090] Microbes may be contacted with the acidic solution and / or material. The microbes may be contacted with an agglomerate. The microbe may be any microbe capable of oxidizing reduced iron and / or sulfur compounds. The microbe may include but is not limited to, members of the bacterial genera including, but not limited to, Acidithiobacillus Leptospirillum, Sulfobacillus, Ferrimicrobium', or a combination thereof; and the archaeal genera including, but not limited to, Acidianus, Acidiplasma, Ferroplasma, Metallosphaera, Thermoplasma, or a combination thereof. The microbe may include, but is not limited to, a mesophile; a moderate thermophile; a thermophile psychrotolerant, mesophilic or thermophilic (moderate or extreme) bacteria or archaea; or a combinationthereof. The microbes may be an acidophilic bacteria or archaea. The microbes may be a thermophilic acidophile.

[0091] The method may comprise identifying a location of a recoverable base metal-bearing material. The locating may be identified using data from a localized area within the material. The method may comprise obtaining mineral composition data from the localized area. Mineral composition data may include, but is not limited to, any information related to a mineral including, but not limited to, concentration, Eh, pH, temperature, viscosity, location, density of the leach, grade, fluid flow, passivation layer, atomic composition, or a combination thereof.

[0092] Obtaining the mineral composition data may comprise using an analytical process. The method may comprise use of an analytical process. The analytical process may be used for or at any step of the method. The method may comprise performing an analytical process on a material or a reagent, e.g., a reagent comprising a thiocarbonyl, fluid, or combination thereof. The analytical process may comprise a test for metals concentration, Eh, pH, temperature, viscosity, location, density of the leach, grade, fluid flow, or a combination thereof.

[0093] The method may comprise using a heap ore map to identify the location of a material comprising base metal sulfide from which a base metal may be recovered. The method may comprise an acidic solution metering system. The acidic solution metering system may be used for surface and / or subsurface solution distribution. The acidic solution comprising an oxidant and a thiocarbonyl reagent may be metered to a leaching stockpile. Metering may be achieved by regulating pressure and / or flow rate to achieve a given operational condition. The operational condition may be selected to optimize a set of operational parameters to recover a metal. The surface and / or subsurface leaching distribution system may be configured to convey the acidic solution at the known flow rate and / or pressure. The acidic solution may be conveyed to the location of the target material under a surface of a heap to recover the metal. The acidic solution may also comprise a chelating agent.

[0094] Determining the ore map may comprise adding flow data; irrigation data; a prediction from a machine learning or artificial intelligence model; or combination thereof to generate data by section and by date within a material, e.g., a heap. The method mayfurther comprise determining x,y,z coordinates for the identified location of a material. Determining an ore map may comprise analyzing data from a geographic and / or geologic mapping program including but not limited to satellite, drone, or airplane; and / or historical date for metal placement and / or recovery.

[0095] The acidic solution metering system may comprise a plurality of acidic solution regulating modules. The acidic solution regulating module may comprise a meter configured to detect a pressure or a flow rate of the acidic solution. The acidic solution regulating module may comprise a regulator configured to set a pressure or flow rate of the acidic solution to a target operational condition. The acidic solution regulating module may comprise a transmitter configured to transmit a pressure or flow rate of the acidic solution to a control system.

[0096] The method may contact the material disposed in the identified location with acidic solution comprising a chelating agent and a reagent comprising a thiocarbonyl.

[0097] The method may comprise at least partially disposing a subsurface acidic solution distribution system into, or in proximity to, an identified location. The subsurface acidic solution distribution system may be in communication with an acidic solution regulating system. The subsurface acidic solution distribution system may comprise a subsurface injector configured to convey acidic solution comprising a reagent comprising a thiocarbonyl under a surface of a heap to extract a metal. The subsurface injector may be configured to convey an acidic solution comprising a reagent comprising a thiocarbonyl into, or in proximity to, an identified location. The acidic solution comprising a reagent comprising a thiocarbonyl may further comprise a chelating agent and may allow material disposed in the identified location to be susceptible to further extraction. The subsurface injector may be at least partially disposed into a bore formed in the heap. A substance capable of providing stability and / or sealing for the subsurface injector may be disposed into the bore. The system may comprise a sensor disposed along a length of the subsurface injector.

[0098] The method may comprise targeting an operational condition for a metal recovery. A target operational condition may be selected by a recovery process operator to allow improved metal recovery efficiency, amount, and / or extraction rate. The target operational condition may be controlled by a plurality of factors including, but not limited to, pressure, flow rate, or a combination thereof. The target operational condition may beselected based on an operational parameter including, but not limited to, mineralogy, chemistry, permeability, remaining recoverable metal, or a combination thereof. A target operational condition may be selected to achieve a given outcome. The given outcome may include, but is not limited to, a recovery amount, percentage, or rate; a permeability loss limit; an acidic solution egress from material limit; or a combination thereof. The target operational condition may be adjusted throughout the method and may be changed from one desired outcome to another.

[0099] An acidic solution regulating module may comprise a conduit in communication with at least a portion of a subsurface acidic solution distribution system. The acidic solution regulating module may deliver acidic solution to the subsurface acidic solution distribution system. The acidic solution may comprise a reagent comprising a thiocarbonyl, chelating agent, and an oxidizing agent. The acidic solution regulating module may detect a pressure and / or flow rate, and may allow the acidic solution to be returned to the subsurface acidic solution distribution system. The acidic solution regulating module may comprise a U-shaped geometry or redirectional geometry.

[0100] The acidic solution regulating module may comprise an electronic regulating module that may receive data regarding at least one of a pressure or flow rate. Data may be transmitted through a data network to a monitoring module. The data may be transmitted in real time and / or a batch process. The monitoring module may communicate via a data network, for example, a wireless data network, to an acidic solution regulating module.

[0101] The acidic solution distribution system may comprise a subsurface acidic solution distribution system and an acidic solution regulating module. The acidic solution regulating module may monitor and / or regulate a local area of the acidic solution distribution system. For example, a centralized monitoring system may comprise a measurement transmitter in a measurement network or mesh. A meter and / or transmitter may comprise an electronic module. The electronic module may implement a data transmission protocol. A measurement transmitter may transmit data to a receiver and the measurement transmitter may function as a repeater. The measurement transmitters may transmit data to the receiver. A remote measurement transmitter (i.e. , a measurement transmitter far from the receiver) may transmit data to a measurement transmitter that is closer to the receiver. The measurement transmitter may relay and / or repeat the data transmission to the receiver.

[0102] The receiver may be configured to receive data from a measurement transmitter. The receiver may employ a communication interface such as a data transmission protocol. The receiver may perform preprocessing functions, for example, by aggregating data by measurement transmitter. The receiver may aggregate data and transmit data via a network to a processor. The network may comprise a wired and / or wireless network. The processor may process data from a receiver and perform an analytical routine. The processor may comprise a distributed control system (DCS) including, but not limited to, a Delta V, SIMATIC PCS7, Pavilion 8, PlantPAx, or a combination thereof, to process data to and from the receiver.

[0103] The processor may process data from the receiver using any method known in the art. For example, the processor may perform graphical analysis; implement a human machine interface (HMI); or a combination thereof. The HMI which may allow a user to analyze data provided by the processor and make decisions with respect to the status, e.g., functionality, of an acidic solution distribution system.

[0104] The ore map may comprise a plurality of data inputs from the metal recovery process and / or a metal recovery facility, e.g., a mine. The data input may include, but is not limited to, ore placement data collected by dispatch data, truck sensor data, geographic information system (GIS) polygon data, mineralogy data, e.g., from a block model, aerial methods including but not limited to satellite, airplane, or drone, or a combination thereof.

[0105] The ore map may be configured to communicate with a tracking system and receive a data input from the tracking system. The ore map may comprise a representation of the total mineralogy for a material. The total mineralogy may be obtained from the tracking system, section mapping irrigation, polygons, or a combination thereof. The ore map may comprise irrigation data and remaining base metal prediction data from a machine learning model. The irrigation data and remaining base metal prediction data may be used to obtain information by section and by date for a material. The ore map may use data including, but not limited to, where a base metal originates from; where a base metal is disposed within a material; what amount of a base metal remains in a material; or a combination thereof. The ore map may be merged with temporal data. The temporal date may comprise the date at which a level (e.g., lift) and section of a heap was constructed. The ore map may combine PLS grade and flow and / or chemistry (e.g., acid) data with the time a level and / or section of the heap is irrigated with the acidic solution. The ore mapmay merge the data of heap construction and irrigation. The ore map may provide raffinate and / or pregnant leach solution chemistry data and / or irrigation data at each level and / or section of the heap.

[0106] A flow condition associated with the acidic solution may be selected and / or modified. For example, a flow rate associated with the acidic solution may be "pulsed" between a relatively low flow rate and a relatively high flow rate. The composition of the acidic solution may also be modified based on the chemical properties of the material subject to metal recovery. A flow condition of the acidic raffinate solution may also be modified to increase the quantity of metal recovered.

[0107] The method may comprise a well monitoring configuration. The well monitoring configuration may comprise a sensor disposed along a length of a subsurface injector. The sensor may be any device capable of measuring and communicating a pressure and / or flow rate of the acidic solution. The sensor may be configured to monitor flow through a slotted portion of the well. The sensor may be configured to monitor a flow condition related to the acidic solution. The status of flow may be measured at the subsurface injector and may be transmitted by a mesh network to a process control system. The sensor may be configured to monitor a solution characteristic including, but not limited to, oxygen content, temperature, or a combination thereof. A plurality of sensors may be disposed along any well at or near the subsurface injector. The sensors may be disposed in approximately 5-foot, 10-foot, 15-foot, 20-foot increments, or a combination thereof, or any other increment of length. The well monitoring configuration may comprise a sensor array that may extend along any length of the subsurface injector including, but not limited to, along an entire length of the subsurface injector. The sensor may be in communication with a signal wire which may extend along the subsurface injector and / or out of the surface. The signal wire may transmit information obtained by the sensor to an acidic solution regulating system. The well monitoring configuration may wirelessly communicate information obtained by the sensor.

[0108] The method may comprise controlling an operating parameter based on the measured or modelled data. The method may comprise selecting an aeration rate of the heap based on an operating parameter value. The operating parameter may include, but is not limited to, dissolved oxygen concentration of the acidic solution; carbon dioxide concentration of the acidic solution; temperature of acidic solution from the heap (i.e. , a pregnant leach solution temperature); temperature of the acidic solution (raffinate)contacted with the material; heap temperature; pregnant leach solution metal concentration; pregnant leach solution oxidation potential; ferric and / or ferrous iron concentration in an acidic solution; Eh value; material oxygen uptake rate; material carbon dioxide uptake rate; or a combination thereof.

[0109] The method may comprise determining the oxidation rate of copper- containing sulfidic material. The oxidation rate may be a function of a parameter including, but not limited to, carbon dioxide concentration of the material; temperature of the acidic solution discharged from the material (i.e., temperature of a pregnant leach solution); raffinate temperature; material temperature; pregnant leach solution metal content; pregnant leach solution oxidation potential; ferric and / or ferrous iron concentrations; Eh value; a material oxygen uptake rate; a material carbon dioxide uptake rate; a simulation based on an acidic solution composition; a sulfide mineral extraction rate; the geometry of the material; an environmental condition external to the material; historical data from existing material; or a combination thereof.

[0110] The method may comprise selecting an aeration rate of the material. The aeration rate may be based on a desired copper oxidation rate, microbial population and / or activity and / or a desired material temperature. The method may comprise monitoring the temperature of the material. The method may comprise monitoring the temperature at a given location. The location may be along the height and / or width of the material and may be at least about 1%, about 1% to about 95%, about 10% to about 90%, about 20% to about 80%, about 30% to about 70%, about 40% or about 60% of the material below a surface of the material. The method may comprise measuring the pregnant leach solution temperature. Measuring the pregnant leach solution temperature may indirectly measure the material temperature. The aeration rate may be controlled by controlling an irrigation rate. The irrigation rate may be controllable using a rest-rinse cycle or varying the flowrate of the acidic solution.

[0111] The method may comprise contacting the material with elemental sulfur. The elemental sulfur may be added, a byproduct of a sulfidic material, endogenous to the material, or a combination thereof. The elemental sulfur may accelerate the production of sulfate.

[0112] The method may comprise agglomerating the material. Agglomeration may comprise mixing and agglomerating material comprising a base metal sulfide and sulfidicmaterial comprising a base metal. Agglomeration may comprise mixing material in one step and then agglomerating the mixed material in a second step. There may be overlap between the mixing and agglomeration steps. Agglomeration may comprise agglomerating material comprising base metal sulfide and sulfidic material comprising a base metal in an agglomeration unit and may comprise providing a material, reagent comprising a thiocarbonyl, and / or a second reagent at, or in close proximity to, an inlet of an agglomeration unit.

[0113] The agglomeration step may comprise agglomerating a material comprising a base metal sulfide and sulfidic waste comprising a base metal in an agglomeration unit. The method may comprise disposing a reagent comprising a thiocarbonyl; a second reagent; an acid; a microbe; silver; a chloride; a bromide; an iodide; a complexing agent to enhance the dissolution of a base metal from a base metal sulfide by forming a complex between sulfur that has originated from the material; pyrite; a material comprising elemental sulfur; a material comprising reduced sulfur compounds; a material comprising reduced iron compounds; water; other water sources; a pregnant leach solution from a extraction operation; a pregnant leach solution from raffinate formed in a solvent extraction operation on the pregnant leach solution; or a combination thereof, into, at, or in close proximity to, an inlet of the agglomeration unit. The elemental sulfur may be a partial or complete replacement of sulfuric acid and / or pyrite.

[0114] The material may be configured for microbial-assisted extraction. The microbial-assisted extraction for material comprising a base metal sulfide and sulfidic material comprising a base metal, may be a heap leaching operation comprising: a heap of material comprising a base metal sulfide and sulfidic material comprising a base metal; and a reagent comprising a thiocarbonyl. Optionally the acidic solution may comprise a second reagent and may comprise sulfate. The acidic solution may flow downwardly though the material and extract a base metal from a base metal sulfide and sulfidic material comprising a base metal. The method may comprise collecting a pregnant leach solution comprising the base metal in solution from the material, wherein the sulfate concentration in the acidic solution is controlled so that it does not exceed a threshold concentration.

[0115] The material may be in the form of agglomerates of material and the agglomerates may comprise a second reagent including, but not limited to, silver, sulfuric acid, pyrite, an activation agent for silver, elemental sulfur, other reduced sulfur compounds, other reduced iron compounds, a complexing additive agent, or a combinationthereof. The agglomerates may comprise a second reagent, such as a surfactant and / or wetting agent. The method may comprise contacting the material with pyrite. Pyrite may generate acid and heat in the material and may promote extraction of the metal from the base metal sulfide and sulfidic material containing a base metal. Other sulfides, e.g., pyrrhotite, may also generate heat and acid.

[0116] The initial sulfate concentration in the material and / or acidic solution may be up to 20 g / L, about 0.001 g / L to about 20 g / L, about 0.01 g / L to about 18 g / L, about 0.1 g / L to about 16 g / L, about 1 g / L to about 14 g / L, or about 20 g / L. The sulfate concentration may increase over time.

[0117] The granular material may comprise crushed rock, sand, gravel, or a combination there. The air delivered via the aeration system may be ambient air. The air delivered by the aeration system may be heated and may be heated as part of the aeration system. The aeration system may be at least partially disposed on a support surface. The support surface may comprise a liner. A drainage system may be in communication with the support surface. Granular material may be disposed above the support surface. A polymer layer and / or cover may be disposed above, or be in contact with, the material.

[0118] The method may comprise contacting elemental sulfur or a su Ifi decontaining additive with the material. The method may comprise configuring the material into at least two process zones wherein the metal recovery is at least partly controlled. The elemental sulfur may at least partially replace acid (e.g., sulfuric acid) and / or pyrite. The material, a reagent comprising a thiocarbonyl, and / or a second reagent may be contacted at the same location or at different locations along the length of an agglomeration unit.

[0119] The method may comprise forming an agglomerate for heap leaching a base metal sulfide and sulfidic material comprising a base metal that includes agglomerating material comprising copper-containing sulfidic ores materials and other materials in an agglomeration unit. The agglomeration unit may comprise an inlet end and an outlet end configured to convey material along a length of the agglomeration unit from the inlet end to the outlet end, with the method comprising contacting the material with the agglomeration unit at, or close to, the inlet end, no more than 40%, no more than 30%, no more than 20%, of the length from the inlet end of the agglomeration unit.

[0120] The agglomeration step may comprise agglomerating a material comprising a base metal sulfide and sulfidic waste comprising a base metal in an agglomeration unit.The method may comprise contacting an agglomeration unit with a reagent comprising a thiocarbonyl; a second reagent; an acid; a microbe; silver; a chloride; a bromide; an iodide; a complexing agent to enhance the dissolution of a base metal from a base metal sulfide by forming a complex between sulfur that has originated from the material; pyrite; a material comprising elemental sulfur; a material comprising reduced sulfur compounds; a material comprising reduced iron compounds; water; other water sources; a pregnant leach solution from a extraction operation; a pregnant leach solution from raffinate formed in a solvent extraction operation on the pregnant leach solution; or a combination thereof, at, or in close proximity to, an inlet of the agglomeration unit. The elemental sulfur may be a partial or complete replacement of sulfuric acid and / or pyrite.

[0121] The method may comprise adding pyrite to a material. The pyrite may be in any suitable form including, but not limited to, a solid, as part of a solution, or a combination thereof. The pyrite may be agglomerated with the material. The pyrite may be at least about 0.1 weight percent (wt%), about 0.1 wt% to about 25 wt%, about 1 wt% to about 20 wt%, about 10 wt% to about 15 wt%, or about 25 wt% of the total mass of the agglomerate. The pyrite may be obtained from any suitable source and may be contained in the material. The pyrite particles may be any suitable size. The pyrite particles in the material may comprise a particle size of about P80 of 1 mm or a value less than 1 mm to about a P80 of 250 pm or a value <250 pm.

[0122] The method may comprise forming the material into particles. The size and / or shape of the particles may be optimal for base metal recovery from the material. Forming the material into particles may be done by any suitable method. The method may comprise ablating a material. The material may be ablated at any step of the method. The method may be ablated by any method including, but not limited to, contacting material against a surface, contacting a first portion of material against a second portion of material.

[0123] The method may comprise identifying material that does not comprise a base metal and / or selectively removing and / or separating the material comprising the base metal from material that does not comprise the base metal. Selective removal and / or separation may be achieved by any suitable method including, but not limited to, size separation, density separation, conductivity, or a combination thereof. The material may be in particles.

[0124] The method may comprise wet grinding, milling, grinding, crushing and / or comminuting a material to forming the material into particles. The method may comprise at least partially disposing copper powder and material formed into particles into a basic or acidic leaching vessel configured to receive the copper powder and material formed into particles to produce a basic or acidic pregnant leach solution. The method may comprise contacting the material formed into particles with a solvent extraction train configured to receive the fluid portion of the pregnant leach solution. The method may comprise contacting the material formed into particles with a basic solution comprising ammonia and a reagent comprising a thiocarbonyl. The basic solution may be used to extract a metal from a material. Wet grinding may be accomplished through any grinding technique known in the art. Wet grinding may comprise conveying crushed ore to a semi-autogenous grinding mill followed by wet ball and / or rod mill grinding in a closed circuit.

[0125] The reagent comprising a thiocarbonyl may react with the passivation layer and may form an additional chemical substance, e.g., a byproduct or reaction product. The additional chemical substances may include, but are not limited to, formamidine disulfide, elemental sulfur, cyanamide, ammonia, carbon dioxide, any intermediate substance from reactions of the thiocarbonyl compound and the material, raffinate or pregnant leach solution, or a combination thereof. The additional chemical substance may remain in a leach stockpile; may be recirculated through a raffinate pond; may be recirculated through a PLS pond; may be separated out of the PLS; be reintroduced into the raffinate in its reacted or unreacted form; be routed to a leach circuit to disrupt, e.g., break apart, erode, or remove, the passivation layer; be reacted to form the original catalyst or another functional group catalyst at any stage of the method or after being separated out of the PLS; be introduced into the raffinate to facilitate the disruption of the passivation layer in the leach circuit; or a combination thereof.

[0126] The reagent comprising the thiocarbonyl and / or the additional chemical substance may be routed to the solvent extraction circuit and may be recirculated through the raffinate pond. The reagent comprising the thiocarbonyl and / or the additional chemical substance may be separated out of the solution and may be routed back to the leach circuit to disrupt e.g., break apart, erode or remove, the passivation layer. The reagent comprising the thiocarbonyl and / or the additional chemical substance may be reacted to form another catalyst that may be routed to the leach circuit to disrupt the passivation layer.

[0127] The reagent comprising the thiocarbonyl may react with the passivation layer to form an additional chemical substance or may be in solution with a passivation layer chemical substance. A reaction may occur to regenerate the thiocarbonyl or form another catalyst that may be routed back to the leach circuit to disrupt the passivation layer.

[0128] The reagent comprising the thiocarbonyl may solely function to disrupt the passivation layer and may allow the extraction of a base metal from a base metal sulfide with or without an acidic solution. Alternatively, the reagent comprising the thiocarbonyl may react with the base metal sulfide after disrupting the passivation layer which may produce another base metal-bearing substance. The other base metal-bearing substance may be recovered in the solvent extraction and / or electrowinning processes and may produce a cathode (e.g., a copper cathode) or any other metal product such as metal rich precipitates, metal powder, metal cementation product, etc.

[0129] A base metal sulfate bearing solution may be routed to the solvent extraction circuit for purification which may result in the production of a metal cathode in an electrowinning circuit. Another base metal substance may be produced using the reagent comprising the thiocarbonyl that may in turn produce a base metal product including, but not limited to, a copper cathode, a metal rich precipitate, a metal powder, a metal cementation product, a metal salts, or a combination thereof.

[0130] The method may comprise excess and / or unreacted reagent comprising a thiocarbonyl in the PLS that may route to a raffinate pond and / or to the leach circuit to facilitate the disruption of the passivation layer. The reagent comprising a thiocarbonyl or additional chemical substances, e.g., a reaction product of the reagent comprising a thiocarbonyl may be present in an electrowinning circuit.

[0131] The reagent comprising a thiocarbonyl may comprise ferric sulfate, ethylene thiourea (Etu), thioacetamide (TA), sodium-dimethyldithiocarbamate (SDDC), ethylene trithiocarbonate (ETC), thiosemicarbazide (TSCA), thiourea, formamidine disulfide, isothiourea; N-N' substituted thioureas, of which 2-Thioxoimidazolidine or N,N'- Ethylenethiourea) are examples; 2,5-dithiobiurea; dithiobiuret; thiosemicarbazide purum; methyl chlorothiolformate; dithiooxamide; 2-methyl-3-thiosemicarbazide; 4-methyl-3- thiosemicarbazide; vinylene trithiocarbonate purum; vinylene trithiocarbonate; 2- cyanothioacetamide; potassium ethyl xanthogenate; dimethylthiocarbamoyl chloride; dimethyldithiocarbamate; S,S'-dimethyl dithiocarbonate; dimethyl trithiocarbonate; N,N-dimethylthioformamide; 4,4-dimethyl-3-thiosemicarbazide; 4-ethyl-3-thiosemicarbazide; 0- isopropylxanthic acid; ethyl thiooxamate; ethyl dithioacetate; pyrazine-2-thiocarboxamide; diethylthiocarbamoyl chloride; diethyldithiocarbamate; tetramethylthiuram monosulfide; tetramethylthiuram disulfide; pentafluorophenyl chlorothionoformate; 4-fluorophenyl chlorothionoformate ; O-phenyl chlorothionoformate; phenyl chlorodithioformate; 3,4- difluorothiobenzamide; 2-bromothiobenzamide; 3-bromothiobenzamide; 4- bromothiobenzamide; 4-chlorothiobenzamide; 4-fluorothiobenzamide; thiobenzoic acid; thiobenzamide; 4-phenylthiosemicarbazide; O-(p-tolyl) chlorothionoformate; 4-bromo-2- methylthiobenzamide; 3-methoxythiobenzamide; 4-methoxythiobenzamide; 4- methylbenzenethioamide; thioacetanilide; salicylaldehyde thiosemicarbazone; indole-3- thiocarboxamide; S-(thiobenzoyl)thioglycolic acid; 3-(acetoxy)thiobenzamide; 4- (acetoxy)thiobenzamide; methyl N'-[(e)-(4- chlorophenyl)methylidene]hydrazonothiocarbamate ; 3-ethoxythiobenzamide; 4- ethylbenzene-1 -thiocarboxamide; tert-butyl 3-[(methylsulfonyl)oxy]-1-azetanecarboxylate; diethyldithiocarbamic acid; 2-(phenylcarbonothioylthio)propanoic acid; 2- hydroxybenzaldehyde N-ethylthiosemicarbazone; (1 R,4R)-1 ,7,7- trimethylbicyclo[2.2.1]heptane-2-thione; tetraethylthiuram disulfide; tetraethylthiuram disulfide; 4’-hydroxybiphenyl-4-thiocarboxamide; 4-biphenylthioamide; dithizone; 4’- methylbiphenyl-4-thiocarboxamide; tetraisopropylthiuram disulfide; anthracene-9- thiocarboxamide; phenanthrene-9-thiocarboxamide; sodium dibenzyldithiocarbamate; and 4,4'-bis(dimethylamino)thiobenzophenone, or a combination thereof.

[0132] The method may comprise contacting a material, raffinate, pregnant leach solution, acidic solution, any other fluid, or a combination thereof, with a reagent at any point in the method including, but not limited to, the extraction of a metal from a material, in a raffinate pond, pregnant leach solution pond, or during the solvent extraction process and / or electrowinning process, or in the transfer from each of these unit operations.

[0133] The method may comprise contacting a material with a counter ion and / or chelating agent, oxidizing agent, or a combination thereof. The counter ion and / or chelating agent may include, but is not limited to, citric acid, nitrates, permanganates, ethylenediaminetetraacetic acid (EDTA), other counter ions and / or chelating agents known in the art to associate with a metal, or a combination thereof. The chelating agent may be at a concentration in the range at least about 0.001 g / L, about 0.001 g / L to about 20 g / L, about 0.05 g / L to about 15 g / L, about 0.1 g / L to about 10 g / L, about 1 g / L to about 10 g / L, about 2 g / L to about 5 g / L, or about 20 g / L.

[0134] The oxidizing agent may include, but is not limited to, ferric sulfate, chlorate, perchlorates, nitrates, permanganates, hydrogen peroxide, oxygen, fluorine, chlorine, bromine, iodine, hydroxyl radical, superoxide, hydroperoxide radical, oxygen, hypochlorous acid, hypofluorous acid, hypobromous acid, hypoiodous acid, dichloride radical, dibromide radical, diiodide radical, ozone, O-atom, carbonate radical, azide radical, amino radical, nitrogen dioxide radical, nitrogen trioxide radical, phosphite radical, phosphate radical, sulfite radical, sulfate radical, peroxomonosulfate radical, selenite radical, dithiocyanate radical, chlorine dioxide, permanganate, ferrate, bromine dioxide, perborate, lead dioxide, aqua regia (3HCI + HNO3), concentrated nitric acid, HNO3+H2SO4, persulfate, Caro’s Acid, perchlorate, chromic acid, chromium trioxide, nitrous oxide, nitrogen dioxide, peroxides, or a combination thereof. The oxidizing agent may be at a concentration in the range of about 0.001% to about 10%, about 0.5% to about 8%, about 1% to about 6%, about 2% to about 5%, or about 10%. The oxidizing agent may be at a concentration in the range of at least about 0.001 g / L to about 50 g / L, about 0.01 g / L to about 45 g / L, about 0.1 g / L to about 40 g / L, about 1 g / L to about 35 g / L, about 2 g / L to about 30 g / L, about 5 g / L to about 25 g / L, about 10 g / L to about 20 g / L, or about 50 g / L.

[0135] Without being limited to one particular theory, the reagent comprising the thiocarbonyl may disrupt, e.g., break apart, erode or remove, the passivation layer of base metal on a sulfide ore to facilitate metal recovery through a physical or an electrochemical mechanism. A plurality of base metal may be extracted from a material. The base metals may be extracted simultaneously or sequentially.

[0136] The method may comprise contacting a material with a support surface, a layer of granular material located on the support surface; and a layer of base metal sulfide and sulfidic material comprising a base metal at least partially disposed above the granular material layer. The method may comprise disposing an irrigation system within, onto, and / or in proximity to, the material. The irrigation system may be configured to convey an acidic solution and / or a hot solution through the granular layer. The method may comprise a collection system within, onto, and / or in proximity to, the material. The collection system may be configured to collect a pregnant leach solution comprising a base metal from the material. The method may comprise an aeration system within, onto, and / or in proximity to, the material. The aeration system may be configured to convey a gas to the material. The gas may react with the base metal sulfide and / or sulfidic material comprising a base metalin a material. The method may comprise a control system within, onto, and / or in proximity to, the material. The control system may monitor and / or modify an operating parameter.

[0137] The method may comprise recovery of metal from a material using a cosolvent. The cosolvent may comprise a water and alcohol cosolvent system. Compared with an entirely aqueous solvent, the use of a cosolvent has several advantages including: enhancing the wettability of the cosolvent system by lowering its surface tension; providing a chemical catalytic effect through certain functional groups; and stabilizing reagents. The use of a cosolvent system may also be compatible with both bioleaching processes (e.g., using iron / sulfur oxidizing bacteria) and chloride leaching processes.

[0138] The method may or may not use aggressive oxidizing reagents (e.g., ozone and H2O2), elevated temperature, or an ionic liquid. This method allows base metal recovery to be enhanced without compromising other operating parameters and under ambient temperature and / or pressure.

[0139] The beneficial effects from the cosolvents include, but are not limited to, assisting the delivery of oxidants and reagent to a material’s surface by lowering the material’s surface tension; stabilizing the reagent comprising the thiocarbonyl and its derivatives in an acidic solution; providing a synergistic effect between cosolvent and reagent comprising a thiocarbonyl; and / or enhancing base metal recovery by using an alcohol as cosolvent in an acidic ferric chloride and / or cupric chloride solution.

[0140] The alcohol may comprise a monohydric alcohol including, but not limited to, methanol, ethanol, 1 -propanol, isopropanol, 1 -butanol, 2-butanol, iso-butanol, sec-butanol, tert-butanol, 1-pentanol, 2-methyl-1-butanol, 3-methyl-1 -butanol, 2,2-dimethyl-1-propanol, 2-pentanol, 3-methyl-2-butanol, 3-pentanol, 2-methyl-2-butanol, hexanol, heptanol, or a combination thereof. The alcohol may also comprise a polyhydric alcohol including, but not limited to, ethylene glycol, propylene glycol, 1 ,2-propanediol, 1 ,3-propanediol, 1 ,2- butanediol, 1 ,3-butanediol, 1 ,4-butanediol, 2,3-butanediol, glycerol, trimethylolpropane, xylitol, 1 ,1 ,1-tris(hydroxymethyl)propane, pentaerythritol, or a combination thereof. The alcohol may comprise a solubility in water of at least about 0.2 g / L, about 0.2 g / L to about 300 g / L, about 0.5 g / L to about 275 g / L, about 1 .0 g / L to about 250 g / L, about 5 g / L to about 225 g / L, about 10 g / L to about 200 g / L, about 20 g / L to about 175 g / L, about 50 g / L to about 150 g / L, about 75 g / L to about 125 g / L, or about 300 g / L.

[0141] The monohydric alcohol and / or polyhydric alcohol may be at a concentration of at least about 0.02%, about 0.02% to about 25%, about 4% to about 22%, 6% to about 20%, about 8% to about 18%, about 10% to about 16%, about 12% to about 14%, or about 25%. The alcohol may be derived from a methyl ester, ethyl ester, cellulosic material, propyl ester, isopropyl ester, butyl ester, or a combination thereof. The derivation may be achieved by hydrolysis and / or fermentation.

[0142] The cosolvent may comprise polyethylene glycol. The polyethylene glycol may be at a concentration of at least about 0.02%, about 0.02% to about 50%, about 5% to about 45%, 10% to about 40%, about 15% to about 35%, about 20% to about 30%, or about 50%. The polyethylene glycol may comprise a molecular weight of at least about 500 g / mol, about 500 g / mol to about 4500 g / mol, about 750 g / mol to about 4250 g / mol, about 1000 g / mol to about 4000 g / mol, about 1250 g / mol to about 3750 g / mol, about 1500 g / mol to about 3500, g / mol, about 1750 g / mol to about 3250 g / mol, about 2000 g / mol to about 3000 g / mol, about 2250 g / mol to about 2750 g / mol, or about 4500 g / mol.

[0143] The cosolvent may comprise an acid. The acid may comprise a carboxylic acid with or without a hydroxyl substitution. The carboxylic acid may comprise a polyprotic carboxylic acid. The acid may comprise an alcohol feature. The acid may include, but is not limited to, oxalic acid, malonic acid, succinic acid lactic acid, phthalic acid, citric acid, tartaric acid, glycolic acid, malic acid, ascorbic acid, gluconic acid, mandelic acid, hydroxycitric acid, kojic acid, or a combination thereof. The acid may be at a concentration of at least about 2 mM, about 2 mM to about 25 mM, about 4 mM to about 22 mM, 6 mM to about 20 mM, about 8 mM to about 18 mM, about 10 mM to about 16 mM, about 12 mM to about 14 mM, or about 25 mM.

[0144] The method may comprise recovering a base metal from a material by dissolving an alcohol in an acidic solution (e.g., ferric sulfate solution, a ferric chloride solution, and / or a cupric chloride solution). The alcohol concentration in the acidic ferric sulfate solution may be at least about 0.05%, about 0.05% to about 10%, about 1% to about 9%, about 2% to about 8%, about 3% to about 7%, about 4% to about 6%, or about 10% for any bioleaching operation to not compromise any bacterial activity. The alcohol concentration in the acidic ferric chloride and / or cupric chloride solution, may be about 10%, but lower or higher concentrations (e.g., less than about 0.5% or more than about 10%) may be used. A person skilled in the art may determine the concentration of the alcohol depending on economic and operational parameters.

[0145] In an example, in an acidic ferric sulfate media and in the presence of a thiocarbonyl compound and a cosolvent as reagents, the following reaction is facilitated:CuFeS2(s) + 2 Fe2(SO4)3(a) - CuSO4(a) + 5 FeSO4(a) + 2 S°(s) (1)

[0146] In an example, in an acidic ferric chloride and / or cupric chloride solution and in the presence of a thiocarbonyl compound and a cosolvent as reagents, non-oxidative recovery is facilitated according to the following reactions:2H2S + Oxidant ^4H++ 2S° + Reductant (3)

[0147] After chalcopyrite is oxidized, the dissolved copper may be recovered from the pregnant solution. The method may be applied to mineral heaps or dumps, or other contact with minerals. The method may be performed under atmospheric temperature and pressure conditions, although other temperatures and pressures may be used.

[0148] The method may comprise contacting a material with an acidic solution. The acidic solution further comprises an oxidizing agent. The oxidizing agent may be any suitable oxidizing agent or combination thereof, the selection of which can be made by a person skilled in the art. The reduction and / or oxidation potential may be at least about 50 mV, about 50 mV to about 900 mV, about 100 mV to about 800 mV, about 200 mV to about 700 mV, about 300 mV to about 600 mV, about 400 mV to about 500 mV, or about 900 mV. The oxidizing agent may comprise oxygen, a source of Fe3+ions, or a combination thereof. The oxidizing agent may comprise a source of Fe3+(ferric) ions. The term “source” as used herein is in reference to Fe3+ions may comprise both direct sources of Fe3+ions and indirect sources of Fe3+ions, as appropriate. The term “direct source” as used herein is in reference to a source of Fe3+ions refers to a substance such as a suitable water-soluble iron(lll) salt that directly releases the Fe3+ions upon dissolution in an aqueous environment, such as the acidic solutions of the present invention. The term “indirect source” as used herein is in reference to a source of Fe3+ions such as a suitable water soluble iron(ll) salt that releases a substance such as Fe2+ions upon dissolution in an aqueous environment, such as the acidic solutions of the present invention that can be converted into the Fe3+ions, e.g., by an electrochemical process or biooxidation. Forexample, the oxidizing agent can comprise a water-soluble salt such as ferric sulfate (also known as iron (III) sulfate or Fe2(SO4)3) that can act as a direct source of Fe3+ions and / or a water-soluble salt such as ferrous sulfate (also known as iron (II) sulfate or FeSO4) that acts as a direct source of Fe2+ions that can, for example, be oxidized into Fe3+ions, e.g., by iron-oxidizing bacteria. The oxidizing agent comprises ferric sulfate. The source of ferric ions may comprise ferric ions generated at least in part by iron-oxidizing bacteria. The acidic solution may comprise a ferric solution. The acidic solution may comprise a ferric sulfate solution. The acidic solution may comprise a ferric media. The acidic solution may comprise a ferrous sulfate solution. The ferrous sulfate solution may provide a source of Fe2+ions that are oxidized to Fe3+ions by iron-oxidizing bacteria. The concentration of the oxidizing agent such as ferric sulfate in the acidic solution may be any suitable concentration. Prior to the material being contacted with the second reagent and the reagent comprising a thiocarbonyl, the oxidizing agent, e.g., ferric sulfate, may be present in the acidic solution at a concentration of less than 10 g / L of Fe3+. Prior to the material being contacted with the second reagent and reagent comprising a thiocarbonyl, the oxidizing agent, e.g., ferric sulfate, may be present in the acidic solution at a concentration from about 0.5 g / L to about 40 g / L, about 1 .5 g / L to about 3 g / L or about 2 g / L to about 2.5 g / L of Fe3+.

[0149] The acidic solution may comprise a raffinate solution obtained from a previous metal recovery process. For example, the acidic solution may comprise raffinate, acidified water, fresh acid and / or water, acid and / or water, or a combination thereof that may be recycled or reclaimed from another metal recovery process.

[0150] The acidic conditions may comprise contacting the material and / or acidic solution with a gas. The gas may comprise air, enriched air, oxygen, a stoichiometric air and SO2mixture, or a combination thereof. The acidic solution may comprise an extraction aid to improve the extraction efficiency of a metal from a material. The extraction aid includes, but is not limited to, acid, hydrogen peroxide, or a combination thereof. The acidic solution may be heated prior to contact with a material.

[0151] The second reagent may be used in either of the two mainstream acidic solutions (e.g., lixiviants) used in copper hydrometallurgy: an acidic ferric sulfate solution (e.g., acidic ferric sulfate media) or acidic ferric chloride and / or cupric chloride solution (e.g., ferric chloride and / or cupric chloride media). The acidic ferric sulfate solution with iron oxidizing bacteria may rely on an oxidative leaching mechanism. The acidic chloridesolution may rely on a non-oxidative leaching mechanism. A second reagent may be integrated into both systems.

[0152] The acidic ferric sulfate solution may comprise at least about 0 g, about 0 g to about 20 g, about 1 g to about 18 g, about 4 g to about 16 g, about 8 g to about 12 g, or about 20 g of iron (ferric / ferrous) as cation and sulfate as anion. The pH of the acidic ferric sulfate solution may be in the range of at least about 1 , about 1 to about 3, about 1 .5 to about 2.5, or about 3. I ron / sulfur oxidizing bacteria, including but not limited to, Acidithiobacillus ferrooxidans or Acidithiobacillus thiooxidans may be integrated into the acidic ferric sulfate solution. The reagent comprising a thiocarbonyl may be added to the acidic ferric sulfate solution in concentrations of up to 100 mM of a thiocarbonyl while ferric sulfate is added in concentrations of at least about 0 g / L, about 0 g / L to about 20 g / L, about 2 g / L to about 18 g / L, about 4 g / L to about 16 g / L, about 6 g / L to about 14 g / L, about 8 g / L to about 12 g / L, or about 20 g / L of ferric ion.

[0153] The acidic ferric chloride and / or cupric chloride solution may comprise up to at least about 25 g / L, about 25 g / L to about 180 g / L, about 50 g / L to about 150 g / L, about 75 g / L to about 125 g / L chloride. The acidic ferric chloride and / or cupric chloride solution may also comprise up to 5 g / L, at least about 0.1 g / L to about 5 g / L, about 0.5 g / L to about 4.5 g / L, about 1 .0 to about 4.0 g / L, about 1.5 g / L to about 3.5 g / L, about 2.0 g / L to about 3.0 g / L of copper. The acidic ferric chloride and / or cupric chloride solution may also comprise up to 20 g / L, at least about 1 g / L to about 20 g / L, about 2 g / L to about 18 g / L, about 4 g / L to about 16 g / L, about 6 g / L to about 14 g / L, about 8 g / L to about 12 g / L iron. The acidic ferric chloride and / or cupric chloride solution may also comprise up to 2, at least about 0.5 to about 2, about 1 to about 1.5, or about 2 pH.

[0154] The method may comprise performing a solid liquid phase separation on a pregnant leach solution or other fluid comprising a metal. The solid liquid phase separation may include, but is not limited to, contacting the pregnant leach solution or other fluid comprising a metal with a filtration system, a counter-current decantation (CCD) circuit, a thickener, or a combination thereof. The solid liquid phase separation may comprise a conditioning process including, but not limited to, filtration, decanted, precipitation, or a combination thereof. The conditioning process may remove a fine solid particle. The solid liquid separation may separate the pregnant leach solution or other fluid comprising a metal into a liquid portion and a solid portion.

[0155] The material comprising the base metal may be any suitable material comprising a base metal or combination thereof extractable by the processes of the present invention. For example, the material comprising the base metal may be a base metal sulfide or any other suitable material comprising a base metal, or a combination thereof. The material comprising the base metal may comprise a base metal sulfide.

[0156] The acidic conditions are any suitable acidic condition, the selection of which can be made by a person skilled in the art. The method may comprise adding sulfuric acid to obtain the acidic conditions. The pH of the acidic solution may be in a range of from about 0.5 to about 4, about 1 to about 3, or about 1 .5 to about 2.5. The pH of the acidic solution is most optimally about 2.

[0157] The method may comprise contacting the material with a wetting agent. The acidic solution may comprise the wetting agent. The wetting agent may be any suitable wetting agent or combination thereof. The term “wetting agent” as used herein refers to a substance or combination thereof that reduces the surface tension of water, and may comprise suitable surfactants that emulsify and / or disperse in addition to or alternatively, to wetting.

[0158] The wetting agent may be a non-ionic wetting agent. The non-ionic wetting agent may be any suitable non-ionic wetting agent or a combination thereof. The term “non-ionic" as used herein means that the substance does not dissociate into ions in an aqueous environment such as the acidic solutions of the present invention. The amount of the wetting agent used in the processes of the present invention is any suitable amount. For example, it will be appreciated by a person skilled in the art that in embodiments wherein iron-oxidizing bacteria are present, the amount is compatible with the presence of such bacteria, and is desirably selected such that no significant difference is observed in the growth and / or iron oxidation ability of the bacteria. The acidic solution may comprise the wetting agent and prior to the material being contacted with the wetting agent and the reagent having the thiocarbonyl, the wetting agent may be present in the acidic solution at a concentration of from about 0.001 g / L to about 1 g / L, about 0.005 g / L to about 0.5 g / L or about 0.01 g / L to about 0.1 g / L. It will also be appreciated by a person skilled in the art that in embodiments wherein the material is agglomerated in the presence of the wetting agent, such agglomeration may lead to surfactant loss such that additional wetting agent may need to be added prior to and / or during the process to account for such loss.

[0159] The non-ionic wetting agent may be a non-ionic ethoxylate surfactant, a polyethylene glycol, or a combination thereof. The non-ionic wetting agent may be a non- ionic ethoxylate surfactant. The non-ionic ethoxylate surfactant may be any suitable non- ionic ethoxylate surfactant or a combination thereof. The term “surfactant” as used herein refers to an amphiphilic wetting agent; i.e., a substance that contains one or more hydrophobic groups and one or more hydrophilic groups arranged such that the substance is capable of acting as a wetting agent as defined herein. The term “ethoxylate surfactant” as used herein refers to a surfactant that contains at least one suitable ethylene glycol moiety, wherein each ethylene glycol moiety is of the formula -(OC2H4)nOH wherein n is in the range of from 1 to 20, e.g., 1 to 10. The non-ionic wetting agent may comprise polyethylene glycol. The polyethylene glycol may be any suitable polyethylene glycol or a combination thereof. For example, the skilled person will appreciate that polyethylene glycols of low molecular weight (e.g., less than about 2,000 g / mol) may be suitable wetting agents. The polyethylene glycol may have an average molecular weight of from about 100 g / mol to about 600 g / mol or from about 100 g / mol to about 300 g / mol. The polyethylene glycol may comprise polyethylene glycol 200. The non-ionic wetting agent may comprise a combination of a non-ionic ethoxylate surfactant and a polyethylene glycol.

[0160] The non-ionic ethoxylate surfactant may comprise a polysorbate, an alkylphenyl ether of polyethylene glycol or a reduced form thereof, an alkylether of polyethylene glycol or a combination thereof. The non-ionic ethoxylate surfactant may comprise a combination of a polysorbate, an alkylphenyl ether of polyethylene glycol or a reduced form thereof and / or an alkylether of polyethylene glycol.

[0161] The non-ionic wetting agent may comprise a polysorbate. The polysorbate may be any suitable polysorbate or a combination thereof. The term “polysorbate” as used herein refers to a non-ionic surfactant derived from ethoxylated sorbitan esterified with a fatty acid and comprises combinations of such surfactants comprising a mixture of fatty acids.

[0162] The method may comprise contacting the material with a halide. The acidic solution may comprise a halide. The halide ions may comprise chloride ions, bromide ions, iodide ions, or a combination thereof. The concentration of chloride may be about 20 g / L or less, about g / L or less, about 80 g / L or less, about 20 g / L or less, in a range of about 20 g / L to about 120 g / L, in a range of about 20 g / L to about 80 g / L, or in a range of about 20 g / L to about 50 g / L. The concentration of iodide may be about 300 ppm or less, about 100 ppm orless, or in a range of about 100 ppm to about 300 ppm. The concentration of bromide may be about 10 g / L or less, about 30 g / L or less, or in a range of about 10 g / L to about 30 g / L.

[0163] The method may comprise contacting the material with carbonaceous matter. The acidic solution may comprise a carbonaceous matter. The carbonaceous matter may be any suitable carbonaceous matter. For example, suitable carbonaceous matter is at least substantially optionally fully insoluble, and at least substantially optionally fully a solid under the recovery conditions used in the method of the present invention, and is optionally in the form of particles and / or chunks. It will be appreciated by the person skilled in the art that in some embodiments, for example, wherein the carbonaceous matter is agglomerated with the material, such particles or chunks may not exist as discrete particles or chunks but would, for example, be agglomerated together into a suitable mass. The carbonaceous matter may include, but is not limited to, carbon black, activated carbon, graphite, carbon anode scrap, charcoal, coal, solid organic carbon, carbon naturally present in the material comprising the base metal (e.g., an ore), or a combination thereof. The carbonaceous matter may comprise carbon black particles. The dosage and particle size of the carbonaceous matter can be any suitable dosage and particle size. For example, it will be appreciated by a person skilled in the art that in embodiments wherein iron-oxidizing bacteria are present, the dosage is compatible with the presence of such bacteria and is desirably selected such that no significant difference is observed in the growth and / or iron oxidation ability of the bacteria. The dosage of the carbonaceous matter may be about 1 g or lower of carbonaceous matter per gram of ore. Advantageously, a lower dosage and finer particle size of the carbonaceous matter may be used to maximize the contact between the material comprising the base metal sulfide (e.g., the chalcopyrite) and the carbonaceous matter. Accordingly, the dosage of the carbonaceous matter may be from about 0.001 g to about 0.25 g, about 0.01 g to about 0.1 g or about 0.05 g to about 0.1 g per gram of the base metal sulfide (e.g., chalcopyrite) in the material comprising the base metal sulfide. The particle size of the carbonaceous matter may be less than 500, 100 or 30 microns.

[0164] The method may comprise contacting the material or acidic solution with an acid. The acid may be used at any step of the method. The method may comprise contacting a material or a reagent, e.g., a reagent comprising a thiocarbonyl, with an acid. The acid may include, but is not limited to, sulfuric acid; hydrofluoric acid; hydrochloric acid; hydrobromic acid; sulfurous acid; nitric acid; perchloric acid; perbromic acid; phosphorous acid; pyrophosphoric acid; sulfamic acid; fluosilicic acid; selenous acid; phosphoric acid; hypophosphorous acid; phosphomolybdic acid; polyphosphoric acid; periodic acid; iodicacid; boric acid; molybdic acid; tungstosilicic acid; phosphotungstic acid; chlorosulfonic acid; chloroplatinic acid; meta-phosphoric acid; hexafluorophosphoric acid; tetrafluoroboric acid; nitrosylsulfuric acid; hydroxylamine-O-sulfonic acid; hydrogen cyanide; hydrogen azide; chromic acid; water; hydrogen sulfide; carbonic acid; hydrogen peroxide; ammonium; arsenous acid; arsenic acid; others known to those skilled in the art or a combination thereof.

[0165] The method may comprise contacting the material or acidic solution with a flocculant. The flocculant may be used at any step of the method. The method may comprise contacting a material or a reagent, e.g., a reagent comprising a thiocarbonyl, with a flocculant. The flocculant may be organic, inorganic, ionic, and / or nonionic. The flocculant may include, is not limited to, acrylamide, polyacrylamide, a bio-polymer, silicate ions, sodium silicate, colloidal silica, H3SiO4-, polyacrylamide, carboxymethyl cellulose, polyanionic cellulose, polyelectrolytes, including but not limited to, polysaccharides, cationic starch, chitosan, chitosan acetate, and poly-y-glutamic acid, functionalized nanoparticles, nanocellulose, tannin-based flocculants, aluminum sulfate, aluminum chloride, sodium aluminate, ferric sulfate, ferrous sulfate, ferric chloride, ferric chloride sulfate, hydrated lime, magnesium carbonate, aluminum ch loro hydrate, polyaluminum chloride, polyaluminum sulfate chloride, polyaluminum silicate chloride, polyferric sulfate, ferric salts, diallydimethyl ammonium chloride, others known to those skilled in the art or a combination thereof.

[0166] The method may comprise contacting the material or acidic solution with a buffer. The buffer may be used for or at any step of the method. The method may comprise contacting a material or a reagent, e.g., a reagent comprising a thiocarbonyl, with a buffer. The buffer may comprise bicarbonate, soda ash, H+, Na+, K+, Rb+, Cs+, NH4+, Be2+, Mg2+, Ca2+, Sr2+, Ba2+, Al3+, Bi2+, tetraphenylphosphonium, tetraalkylammonium, 1- ethyl-3-methylimidazolium and derivatives, ionic liquid cations, F, Cl’, Br, I; borate, nitrate, sulfate, phosphate, bromate, chlorate, iodate, acetate, formate, tetrafluoroborate, hexafluorophosphate, tetraphenylborate, tetrakis(pentafluorophenyl) borate, ionic liquid anions, or a combination thereof.

[0167] The method may comprise contacting the material or acidic solution with a fluid collector. The fluid collector may be used for or at any step of the method. The method may comprise contacting a material or a reagent, e.g., a reagent comprising a thiocarbonyl, fluid, or combination thereof with a fluid collector. The fluid collector maycomprise a vessel, tank, reactor, tub, sample holder, or any other container for holding the fluid. The fluid may be collected and / or processed by the fluid collector. For example, the pH of fluid in a fluid collector may be adjusted from acidic to neutral.

[0168] The method may comprise recovering a material under pressure. Any step of the method may occur under pressure. The pressure may be at least 1.2 atmosphere, about 1.2 atmospheres to about 100 atmospheres, about 5 atmospheres to about 90 atmospheres, about 10 atmospheres to about 80 atmospheres, about 20 atmospheres to about 70 atmospheres, about 30 atmospheres to about 60 atmospheres, about 40 atmospheres to about 50 atmospheres, or about 100 atmospheres. Any step of the method may occur at a pressure below 1 atmospheres. The pressure may be at least about 0.01 atmospheres to about 0.99 atmospheres, about 0.1 atmospheres to about 0.95 atmospheres, about 0.2 atmospheres to about 0.97 atmospheres, about 0.3 atmospheres to about 0.95 atmospheres, about 0.4 atmospheres to about 0.9 atmospheres about 0.5 atmospheres to about 0.8 atmospheres, about 0.6 atmospheres to about 0.7 atmospheres, or about 0.99 atmospheres. Any step of the method may occur under negative pressure.

[0169] The concentration of the reagent comprising a thiocarbonyl in the acidic solution may be any suitable concentration. In embodiments wherein the reagent comprising a thiocarbonyl is added to the process in the form of the corresponding dimer, the concentrations specified herein for the reagent comprising a thiocarbonyl refers to a concentration calculated as if all of the dimer was dissociated into the reagent having the thiocarbonyl. Prior to the material being contacted with the second reagent and the reagent comprising a thiocarbonyl, the reagent comprising a thiocarbonyl may be present in the acidic solution at a concentration of about 0.001 mM or greater, about 0.02 mM or greater, about 0.1 mM or greater, about 0.2 mM or greater, about 0.25 mM or greater, about 0.3 mM or greater, about 0.4 mM or greater, about 0.5 mM or greater, about 0.6 mM or greater, about 0.7 mM or greater, about 0.8 mM or greater, about 0.9 mM or greater, about 1.0 mM or greater, about 1 .5 mM or greater, about 2 mM or greater, about 2.5 mM or greater, about 3 mM or greater, about 4 mM or greater, about 5 mM or greater, about 10 mM or greater, about 20 mM or greater, about 30 mM or greater, or about 60 mM or greater. Prior to the material being contacted with the second reagent and the reagent comprising a thiocarbonyl, the reagent comprising a thiocarbonyl may be present in the acidic solution at a concentration of about 100 mM or lower, about 60 mM or lower or about 30 mM or lower. Prior to the material being contacted with the second reagent and thereagent comprising a thiocarbonyl, the reagent having the reagent comprising a thiocarbonyl may be present in the acidic solution at a concentration of about 20 mM or lower. A lower concentration of the reagent comprising a thiocarbonyl may be used. Accordingly, prior to the material being contacted with the second reagent and the reagent comprising a thiocarbonyl, the reagent comprising a thiocarbonyl may be present in the acidic solution at a concentration of about 10 mM or lower, about 5 mM or lower, about 4 mM or lower, about 3 mM or lower, about 2.5 mM or lower, about 2 mM or lower, about 1.5 mM or lower, about 1 .0 mM or lower, about 0.9 mM or lower, about 0.8 mM or lower, about 0.75 mM or lower, about 0.7 mM or lower, about 0.6 mM or lower, about 0.5 mM or lower, about 0.4 mM or lower, about 0.3 mM or lower, about 0.2 mM or lower, about 0.02 mM or lower, or about 0.002 mM or lower. It will be appreciated by a person skilled in the art that such embodiments can be interchanged in any suitable manner. For example, prior to the material being contacted with the second reagent and the reagent comprising a thiocarbonyl, the reagent comprising a thiocarbonyl may be present in the acidic solution at a concentration of from about 0.001 mM to about 100 mM, about 0.2 mM to about 100 mM, about 0.2 mM to about 20 mM, about 0.1 mM to about 10 mM, about 0.2 mM to about 10 mM, about 0.2 mM to about 5 mM, about 0.2 mM to about 4 mM, about 0.2 mM to about 3 mM, about 0.25 mM to about 2.5 mM, about 0.2 mM to about 2 mM, about 0.2 mM to about 1.5 mM, about 0.2 mM to about 1.0 mM, about 0.2 mM to about 0.5 mM, about 0.25 mM to about 0.75 mM, about 1 .5 mM to about 2.5 mM, about 0.5 mM or about 2 mM.

[0170] The material can be contacted with the reagent comprising a thiocarbonyl using any suitable process and / or means, the selection of which can be made by a person skilled in the art. The material may be contacted with the reagent comprising a thiocarbonyl in a method comprising a percolation leach (e.g., a heap leach, a dump leach, or a column leach), a tank leach, a vat leach, a bioreactor, or a combination thereof. The material may be contacted with the reagent comprising a thiocarbonyl in a method comprising a percolation leach (e.g., a heap leach, a dump leach, or a column leach), a tank leach or a vat leach. The percolation leach may be a heap leach, a dump leach, a column leach, or a combination thereof. The material may be contacted with the reagent comprising a thiocarbonyl in a method comprising a percolation leach. The material may be contacted with the reagent comprising a thiocarbonyl in a method comprising a heap leach. The material may be contacted with the reagent comprising a thiocarbonyl in a method comprising a dump leach. The material may be contacted with the reagent comprising a thiocarbonyl in a method comprising a column leach. The material may be contacted with the reagent comprising a thiocarbonyl in a method comprising a tank leach.The material may be contacted with the reagent comprising a thiocarbonyl in a method comprising a vat leach. The material may be contacted with the reagent comprising a thiocarbonyl in a method comprising a bioreactor. The material may be contacted with the reagent comprising a thiocarbonyl in a method comprising a leach tank, (e.g., an agitated leach tank). The agitated leaching may be used for or at any step of the method. The method may comprise performing an agitated leach on a material with a reagent, e.g., a reagent comprising a thiocarbonyl, fluid, or combination thereof. Suitable processes, means and / or conditions for carrying out a percolation leach (e.g., a heap leach, a dump leach, column leach), a tank leach, a vat leach agitated leach, or a leach in a bioreactor in the processes of the present invention may be selected by the person skilled in the art.

[0171] For example, the term “percolation leach” as used herein refers to a process in which the base metal is leached from the material by causing the acidic solution to seep into and flow through a mass of the material (or, in some embodiments of the present invention, a mass of the material combined, e.g., agglomerated, with the second reagent).

[0172] The term “heap leach” as used herein refers to an example of a percolation leach which comprises heaping the material (such as the ore) onto a heap leach pad (e.g., an impermeable plastic or clay-lined leach pad), and contacting (e.g., irrigating via a means such as a sprinkler or drip irrigation) the heaped material with the acidic solution in a way such that the acidic solution percolates through the heap and leaches the base metal, for example, so as to obtain a pregnant leach solution comprising the base metal which can be collected. In heap leach processes, the material (such as the ore) may be crushed subsequent to being removed from the ground and prior to being heaped. The crushing may be primary crushing, secondary crushing, tertiary crushing, or a combination thereof. It will be appreciated by a person skilled in the art that in embodiments wherein the material is combined, e.g., agglomerated, with the second reagent, such combining may be carried out prior to the material (such as the ore) and the second reagent being heaped, and, in embodiments comprising crushing the material (such as the ore), subsequent to the crushing of the material.

[0173] The term “dump leach” as used herein refers to an example of a percolation leach having a process that is similar to a heap leach, but wherein the material (such as the ore) is not crushed prior to being stacked on the leach pad.

[0174] The term “column leach” as used herein refers to an example of a percolation leach which comprises loading the material (such as the ore) into a column,then contacting (e.g., irrigating via a means such as drip irrigation from the top of the column) the material with the acidic solution in a way such that the acidic solution percolates through the material in the column and leaches the base metal, for example, so as to obtain a pregnant leach solution comprising the base metal which can be collected. The material (such as the ore) is crushed prior to being loaded in the column. It will be appreciated by a person skilled in the art that in embodiments wherein the material is combined, e.g., agglomerated, with the second reagent, such combining, e.g., agglomeration, is carried out prior to the material (such as the ore) and the second reagent being loaded, and, in embodiments comprising crushing the material (such as the ore), subsequent to the crushing of the material. Column leaches can be useful, for example, for measuring the effects of typical variables encountered in industrial heap and / or dump leaching processes.

[0175] The terms “tank leach’’ and “vat leach’’ as used herein refer to processes in which the material (such as the ore) is disposed into a tank or vat, respectively, containing the acidic solution under conditions suitable to leach the base metal, for example, to obtain a pregnant leach solution comprising the base metal which can be collected. In exemplary tank leaching processes, the material (such as the ore) is ground to a fineness suitable to form a solution or pulp, combined with water to form the solution or pulp, then pumped into the tank where subsequently the acidic solution is added. In exemplary vat leaching processes, a coarser particle size of the material (such as the ore) is used which is loaded into the vat as a solid, then the acidic solution is flooded into the vat.

[0176] The person skilled in the art will appreciate that the term “acidic solution” as used herein comprises both an acidic aqueous solution and an acidic aqueous suspension, depending on the components comprised therein. The acidic solution used in the various embodiments of the present invention can readily be prepared by the person skilled in the art in regard to the present invention by combining the various components therein by a suitable process and / or means. For example, in some embodiments comprising the oxidizing agent (such as ferric sulfate), the acidic solution may be prepared by a process comprising adjusting the pH of an aqueous solution comprising the desired amount of the oxidizing agent (such as ferric sulphate) with a suitable acid (such as sulfuric acid) to a suitable value (such as a pH of about 2) to obtain an acidic aqueous solution comprising the oxidizing agent, then adding the desired amount of the reagent having the thiocarbonyl (or dimer thereof) to obtain the acidic solution. For example, wherein the second reagent is not combined, e.g., agglomerated, with the material (such as the ore), the preparation ofthe acidic solution may further comprise mixing the desired amount of the second reagent in the acidic aqueous solution comprising the oxidizing agent to obtain the acidic solution. The mixing may be prior to the addition of the reagent comprising a thiocarbonyl (or dimer thereof). The mixing may be subsequent to the addition of the reagent comprising a thiocarbonyl (or dimer thereof).

[0177] The method may comprise recovering the base metal. For example, the base metal may be recovered from the pregnant leach solution in embodiments wherein the contacting of the material with the second reagent and the reagent comprising a thiocarbonyl produces a pregnant leach solution comprising the base metal. In embodiments wherein the method comprises recovering the base metal (e.g., from the pregnant leach solution), the method for recovering the base metal may be any suitable process, the selection of which can be made by the person skilled in the art. For example, where the material comprises chalcopyrite, in the presence of the second reagent and reagent comprising a thiocarbonyl, the following reaction is facilitated:CuFeS2(s) + 2 Fe2(SO4)3(aq) -> CuSO4(aq) + 5 FeSO4(aq) + 2 S°(s) (4)

[0178] After the chalcopyrite is oxidized, the dissolved base metal may be recovered (e.g., from the pregnant leach solution). The recovering of the base metal (such as copper) may comprise solvent extraction and electrowinning. Prior to the solvent extraction, the method may comprise a solid-liquid separation.

[0179] The method may further comprise recovering the reagent comprising a thiocarbonyl. For example, the reagent comprising a thiocarbonyl may be recovered from the pregnant leach solution in embodiments wherein the contacting of the material with the second reagent and the reagent comprising a thiocarbonyl produces a pregnant leach solution comprising the base metal. For example, iron and copper ions may be present (e.g., in the pregnant leach solution). A person skilled in the art will appreciate that a reagent comprising a thiocarbonyl may form various stable complexes with base metal ions. Extractants commonly used for solvent extraction of base metal ions, such as hydroxyoximes and aldoximes, are strong complexing agents for the copper ions. The extractants may change the equilibrium between base metal ions and reagent comprising a thiocarbonyl which are acting as ligands, releasing the reagent comprising a thiocarbonyl from the base metal and reagent complex. As the free reagent comprising a thiocarbonyl enters the raffinate solution, it may be recirculated for further contacting with the material. The solvent extraction may comprise contacting the base metal cations (e.g., in thepregnant leach solution) with an extractant for base metal cations in the presence of an organic solvent. The skilled person will be able to select a suitable organic solvent or combination thereof depending on the base metal cation to be extracted. The organic solvent may be an aliphatic solvent, an aromatic solvent, or a combination thereof. The organic solvent may comprise kerosene, alkyl aromatics, cyclo-paraffins, or a combination thereof. The skilled person will also be able to select an appropriate extractant for the base metal cation. The extractant for the base metal cation may be an aldoxime, a ketoxime, or a combination thereof. The contacting may be further carried out in the presence of an ester modifier, an alkylphenol modifier, or a combination thereof. During the solvent extraction, base metal cations may be de-complexed from the reagent comprising a thiocarbonyl, thus liberating the reagent, and allowing the base metal cation to be extracted (e.g., from the pregnant leach solution) into the organic solvent. The free reagent comprising a thiocarbonyl remains in the aqueous phase. The retention of the free reagent comprising a thiocarbonyl in the aqueous phase during solvent extraction is accomplished with halides, e.g., chloride, bromide, or iodide (e.g., in the pregnant leach solution). Separation of the organic solvent from the aqueous phase results in a base metal cation- depleted raffinate comprising the free reagent comprising a thiocarbonyl, and a base metal cation-enriched organic phase comprising the organic solvent and base metal cations. The base metal cation-enriched solution may then be processed (e.g., by a process comprising electrowinning) to recover the base metal. The raffinate can optionally be recirculated for use in the process. Accordingly, the method optionally further comprises recycling the recovered reagent comprising a thiocarbonyl for use in the contacting of a further portion of the material. Additional reagent comprising a thiocarbonyl (or dimer thereof) may be added to reach a desired concentration prior to contacting with the material. A reducing agent may be added prior to contacting with the material. The reducing agent may include, but is not limited to, H2S, NaSH or Zn metal. The reducing agent may be added in an amount to obtain a ratio of reagent comprising a thiocarbonyl to corresponding dimer in a range of about 0.5:1 to about 9:1.

[0180] The contacting of the material with the second reagent and the reagent comprising a thiocarbonyl may be carried out under any suitable temperature and pressure conditions. For example, the contacting can be carried out at a temperature greater than 0°C to about 80°C. However, the contacting in the processes of the present invention is advantageously carried out at ambient temperature (e.g., from about 5°C to about 40°C or about 15°C to about 25°C) and pressure (e.g. , about 1 atm).

[0181] The method may be a batch process, a continuous process, or a combination thereof.

[0182] The present invention also comprises a use of a second reagent and a reagent comprising a thiocarbonyl in a method for extracting a base metal from a material comprising the base metal. The method is any method for extracting a base metal from a material comprising the base metal as described herein.

[0183] The material is contacted with the second reagent and the reagent comprising a thiocarbonyl by any suitable process. The material may be contacted with the second reagent and the reagent comprising a thiocarbonyl by a method comprising: contacting the second reagent with the material; and contacting the combined second reagent and material with an acidic solution comprising the reagent comprising a thiocarbonyl. The second reagent may be agglomerated with the material. Processes for agglomerating are well known in the art and a suitable process for agglomeration of the second reagent and the material may be selected by the skilled person.

[0184] The present invention also comprises a use of a reagent comprising a thiocarbonyl and a second reagent in a method for extracting (e.g., leaching) and optionally recovering a base metal from a material comprising the base metal. The method may comprise recovering the base metal. Accordingly, the present invention also comprises a use of a second reagent and a reagent comprising a thiocarbonyl in a method for extracting (e.g., leaching) and recovering a base metal from a material comprising the base metal. Accordingly, the present invention also comprises a use of a second reagent and a reagent comprising a thiocarbonyl in a method for extracting (e.g., leaching) a base metal from a material comprising the base metal. The process may be any process for extracting (e.g., leaching) and optionally recovering a base metal from a material comprising the base metal as described herein.

[0185] The method may comprise a microbial-assisted heap leach of material or agglomerates of material comprising base metal sulfides, such as chalcopyrite ores, and sulfidic material comprising a base metal in combination with the use of a reagent comprising a thiocarbonyl for extraction of a base metal from a material. The method may comprise controlling the sulfate concentration in an acidic solution in combination with the use of a reagent comprising a thiocarbonyl for extraction of a base metal from a material.The method may comprise forming an agglomerate by contacting a reagent comprising a thiocarbonyl functional group and / or a second reagent with an agglomeration unit, e.g., an agglomerator drum, at, or close to, an inlet end of the agglomeration unit. The thiocarbonyl functional group and / or a second reagent may be contacted anywhere along the agglomeration unit. The thiocarbonyl functional group and / or a second reagent may be contacted at a point less than about 50%, less about 40%, less about 30% or less than about 20% from the inlet of the agglomeration unit. Forming an agglomerate may comprise contacting the agglomeration unit with the acidic solution anywhere along the agglomeration unit. The acidic solution may be contacted less than about 50%, less than about 40%, less than about 30% or less than about 20% from the inlet of the agglomeration unit. The acidic solution may comprise a reagent comprising a thiocarbonyl.

[0186] The method may comprise controlling the pH of the acidic solution in a range that results in the precipitation of a sulfate salt, e.g., jarosite.

[0187] The method may comprise controlling the temperature of the material to be about less than about 85 °C, about 85 °C to about 50 °C, about 75 °C to about 55° C, about 70 °C to about 60° C, or less than about 50 °C. The method may comprise controlling the acidic solution temperature to be above the freezing point of the leach solution, about 0 °C to about 50 °C, about 5 °C to about 45 °C, about 10 °C to about 35 °C, about 15 °C to about 30 °C, about 20 °C to about 25 °C, or about above 50 °C. The irrigation rate may be at a rate of at least about 0.001 L / h / m2, about 0.001 L / h / m2to about 100 L / h / m2, about 0.01 L / h / m2to about 90 L / h / m2, about 0.1 L / h / m2to about 80 L / h / m2, about 1 L / h / m2to about 70 L / h / m2, about 5 L / h / m2to about 60 L / h / m2, about 10 L / h / m2to about 50 L / h / m2, about 20 L / h / m2to about 40 L / h / m2, or about 100 L / h / m2. The method may comprise irrigating using drip irrigation, sprinkler, wobbler, or a combination thereof. The method may comprise performing the method at an oxidation potential of the acidic solution of less than about 1000 mV, about 1000 mV to about 500 mV, about 950 mV to about 550 mV, about 900 mV to about 600 mV, about 850 mV to about 650 mV, about 800 mV to about 700 mV, or less than about 500 mV, where all potentials are with respect to the standard hydrogen electrode.

[0188] The method may comprise forming an agglomerate a known distance from the inlet end, e.g., no more than 40%, of the length of the agglomeration unit measuredfrom the inlet end of the agglomeration unit. The method may comprise attaching a microbe to solids. At least about 50%, about 50% to 95%, about 60% to about 90%, about 65% to about 85%, about 70% to about 80% of microbes may attach to a solid surface. At least about 50%, about 50% to about 5%, about 40% to about 10%, about 35% to about 15%, about 30% to about 20%, or about 5% of microbes may be suspended in solution.

[0189] The base metal sulfide and sulfidic material comprising a base metal may comprise naturally-occurring silver. The naturally-occurring silver may have catalytic properties for base metal extraction, e.g., a base metal from a base metal sulfide. The naturally-occurring silver may include, but is not limited to, native silver; argentite (Ag2S); chlorargyrite (AgCI), as inclusions of silver in a base metal sulfide and pyrite; a silver sulfosalts, e.g., tetrahedrite (Cu, Fe, Zn, Agi2Sb4S13); pyrargyrite (Ag3SbS3); proustite (Ag3AsS3); or a combination thereof.

[0190] The added silver may be contacted with an agglomerate and may be in a solid form or in solution. Solid added silver contacted with an agglomerate may dissolve and become mobile within the acidic solution.

[0191] The added silver may precipitate and / or be at least partially onto a surface of the material comprising a base metal sulfide. The added silver may be dispersed onto a surface of a material comprising base metal-containing sulfidic ores or base metal containing sulfidic materials. The added silver may be dispersed within the material comprising base metal containing sulfidic ores or base metal containing sulfidic material. The added silver may be in soluble form in the material. The added silver may be in an insoluble form and / or sparingly soluble form in the material.

[0192] The agglomerates may comprise a silver concentration lower than the added and / or naturally-occurring silver. The added silver concentration in the agglomerates may be less than about 5 g silver per kg of material, about 5 g silver per kg of material to about 0.001 g silver per kg of material, about 4 g silver per kg of material to about 0.01 g silver per kg of material, about 3.5 g silver per kg of material to about 0.1 g silver per kg of material, about 3 g silver per kg of material to about 0.5 g silver per kg of material, about 2 g silver per kg of material to about 1 g silver per kg of material, or less than about 1 g silver per kg of material.

[0193] The present invention also comprises a use of a reagent comprising a thiocarbonyl for extracting a base metal from a material comprising the base metal,wherein the material is contacted under acidic conditions with the reagent comprising a thiocarbonyl.

[0194] The present invention also comprises a use of a reagent and a second reagent comprising a thiocarbonyl for extracting (e.g., leaching) and optionally recovering a base metal from a material comprising the base metal, wherein the material is contacted under acidic conditions with the reagent comprising a thiocarbonyl. The use may comprise recovering the base metal. Accordingly, the present invention also comprises a use of a reagent comprising a thiocarbonyl and a second reagent for extracting (e.g., leaching) and recovering a base metal from a material comprising the base metal, wherein the material is contacted under acidic conditions with the reagent comprising a thiocarbonyl. The use may not comprise recovering the base metal. Accordingly, the present invention also comprises a reagent comprising a thiocarbonyl and a second reagent for extracting (e.g., leaching) a base metal from a material comprising the base metal, wherein the material is contacted under acidic conditions with the reagent comprising a thiocarbonyl.

[0195] The material may be contacted with the reagent comprising a thiocarbonyl by a method comprising contacting the material with an acidic solution comprising the second reagent and the reagent comprising a thiocarbonyl.

[0196] The method may comprise recovering a base metal from a material comprising a base metal sulfide, the method may comprise: contacting the material with a basic solution, a reducing agent, and a reagent comprising a thiocarbonyl; and recovering the base metal. The basic solution may comprise an ammonia leach medium. The reducing agent may comprise copper powder. Recovering the base metal may comprise separating the material into a pregnant leach solution and a solid and may comprise performing a solvent extraction on the pregnant leach solution. Recovering the base metal may comprise producing a loaded aqueous flow comprising the base metal.

[0197] The method may comprise leaching in a basic solution. The method may comprise contacting a material with a basic media to recover a metal. The basic solution may comprise a pH of at least about 7, about 7 to about 14, about 8 to about 13, about 9 to about 12, about 10 to about 11 , or above 14. The basic solution may include, but is not limited to, ammonia; ammonium and / or ammonium containing compounds; e.g., ammonium carbonate; ammonium sulfate; hypochlorite, e.g., sodium hypochlorite and calcium, hypochlorite, or a combination thereof; peroxide; percarbonate; perborate; or combinations thereof; in addition to a reagent comprising a thiocarbonyl.

[0198] The basic solution may extract metal from the wet ground ore or other material. The basic solution extraction may form a solution comprising a metal. The solution may be processed by a solid-liquid separation. The basic solution, e.g., ammonia solution comprising a reagent comprising a thiocarbonyl, may extract a metal from a material in an agitated tank leach. The agitated tank leach may be performed at constant or varying basic pH levels. Basic pH levels may be at least about 7, about 7 to about 14, about 8 to about 13, about 9 to about 12, about 10 to about 11 , or above 14. The basic leach solution may comprise a recycled solution from upstream processes and recovered lixiviant from various processing steps. Fresh lixiviant may also be added. Recovery may occur in a plurality of tanks with co-current and / or counter-current flow.

[0199] The method may comprise adjusting the oxidation state of copper and / or cobalt. For example, cobalt may be reduced and / or solubilized to cobalt II to extract cobalt II from a material. The reducing agent may comprise any substance capable of acting as a reducing agent including, but not limited to, sulfur dioxide, copper powder, or a combination thereof.Industrial Applicability:

[0200] The invention is further illustrated by the following non-limiting examples.Example 1

[0201] Electrochemical tests were conducted to quantify the degree of passivation of chalcopyrite mineral electrodes subjected to different treatments. Open circuit potential (OOP) and electrochemical impedance spectroscopy (EIS) were used as the primary techniques. The charge transfer resistance (RCT) derived from EIS, was used as a key indicator of surface reactivity or passivity.

[0202] Initial characterization of a fresh mineral surface was performed. The chalcopyrite mineral electrode was polished and immersed in raffinate (Step 1). Initial OOP and EIS measurements were recorded to characterize the unreacted (fresh) mineral surface. The electrode was then left in the raffinate under agitation for 93,650 seconds (approximately 26 hours) to allow natural passive action to occur. This step yielded OCP;and RCT I, representing the electrochemical behavior of the fresh mineral surface prior to and after passive film formation.

[0203] The passivation layer stability was validated. The passivated electrode was removed, rinsed with deionized (DI) water, and re-immersed in raffinate for an additional 7,262 seconds (approximately 2 hours) (Step 2). OCP was monitored continuously, and EIS was measured at the end. This step served as quality control to confirm that the passivation layer is stable and not due to artifacts such as sorption. The resulting data (OCP2 and Rm represented the characteristics of the passivated mineral.

[0204] De-passivation with a reagent comprising a thiocarbonyl functional group was performed. The passivated electrode was rinsed again with DI water and then placed in raffinate containing 50 ppm of the reagent comprising a thiocarbonyl functional group. The solution was agitated for 24 hours in a similar way to steps 1 and 2. This step used the reagent comprising a thiocarbonyl functional group to reverse the passivation of chalcopyrite and created a treated mineral surface for subsequent tests.

[0205] Re-passivation was performed after the removal of the reagent comprising a thiocarbonyl functional group. Following the reagent comprising a thiocarbonyl functional group treatment, the electrode was rinsed with DI water and transferred back into Escondida raffinate (without the reagent comprising a thiocarbonyl functional group) for over 26 hours. OCP was recorded continuously, and EIS was measured at the beginning of the immersion. This step was designed to assess whether the mineral surface repassivates in the absence of the reagent comprising a thiocarbonyl functional group. The resulting measurements (OCP3and RCTS) characterize the electrochemical behavior of the treated mineral.

[0206] Validation of re-passivation layer stability was performed. Finally, the repassivated electrode was rinsed with DI water and re-immersed in raffinate for an additional 2 hours. Similar to step 2, OCP was monitored and EIS was conducted at the end of the test to confirm the stability of the newly formed passivation layer. The final measurements (OCP4and RCT4) represent the characteristics of the re-passivated mineral surface after the reagent comprising a thiocarbonyl functional group was removed.

[0207] Immersion of the freshly polished chalcopyrite electrode into raffinate resulted in an increase in open circuit potential (OCP) from 0.44 V to 0.50 V versus Ag / AgCI, indicating the occurrence of passivation. This rise in OCP reflected the formationof a surface layer that impeded electron transfer. Following rinsing with deionized (DI) water, the elevated OCP remained unchanged, confirming that the shift in potential was due to a stable chemical transformation— rather than a transient phenomenon such as surface adsorption— thereby verifying the formation of a chemically stable passivation layer. Subsequently, the passivated electrode was transferred to an agitated solution of raffinate containing 50 ppm of the reagent comprising a thiocarbonyl functional group.

[0208] After treatment with the reagent comprising a thiocarbonyl functional group and DI water rinsing, the electrode was reintroduced into the original raffinate. An initial OCP of 0.48 V was recorded— lower than the passivated condition (0.50 V) but still higher than that of the fresh, unreacted surface (0.44 V). After 26 hours of immersion, the OCP gradually returned to 0.50 V, indicating re-establishment of the passivation layer. A subsequent DI water rinse confirmed the stability of this re-passivated state as its OCP remained unchanged. These results demonstrated that the reagent comprising a thiocarbonyl functional group could effectively de-passivate chalcopyrite surfaces, but in the absence of the catalyst, the mineral reverts to a similar passivated state in raffinate over time.Example 2

[0209] EIS tests were carried out using the same testing protocol with 10 mV root mean square (RMS) and test frequency ranging from 10 kilohertz (KHz) to 1 hertz (Hz). The results were fitted using a simple Randles circuit (as shown in Fig. 7) with Rs representing solution resistance, CPE for capacitive behavior, RCT representing the charge transfer resistance and W representing typical Warburg element for diffusion process.

[0210] Fitting the electrochemical impedance spectroscopy (EIS) data using an appropriate equivalent circuit model provided insight into the interfacial processes occurring at the mineral surface. As all measurements (except during reagent comprising a thiocarbonyl functional group treatment) were conducted in the same electrolyte (raffinate). Therefore, differences in charge transfer resistance (RCT) were directly attributed to changes in the surface reactivity of the chalcopyrite electrode.

[0211] Upon immersion in raffinate, the RCT increased from 311 Ohms (Q) (freshly polished state) to 596 Cl, representing a 91.6% increase. This rise confirmed the formation of a stable, passivating surface layer that hinders electron transfer. Treatment with thereagent comprising the thiocarbonyl functional group decreased the RCT to 477 Q, indicating that the passivation behavior had been partially reversed and the surface had become more electrochemically active.

[0212] Subsequent re-immersion in raffinate without the reagent comprising the thiocarbonyl functional group led to an increase in RCT to 560 Q. While this value remained lower than that of the initially passivated surface, it is notably higher than both the freshly polished and treated states. This partial recovery of RCT suggested that the surface underwent re-passivation in the absence of the reagent comprising the thiocarbonyl functional group, albeit to a slightly lesser extent than during the initial exposure.

[0213] Previously, similar tests were performed using a piece of chalcopyrite from the same source but using synthetic raffinate (1 .67 g / L Fe, pH 1 .8; the reagent comprising the thiocarbonyl functional group used was at 38 ppm).

[0214] The preceding examples can be repeated with similar success by substituting the generically or specifically described reactants and / or operating conditions of this invention for those used in the preceding examples.

[0215] All percentages are by volume. Unless otherwise indicated, the definitions and embodiments described in this and other sections are intended to be applicable to all embodiments and aspects of the invention herein described for which they would be understood to be suitable by a person skilled in the art.

[0216] Embodiments of the present invention provide a technology-based solution that overcomes existing problems with the current state of the art in a technical way to satisfy an existing problem for the extraction of metal from a material. Embodiments of the present invention achieve important benefits over the current state of the art, such as improved metal recovery. Some of the unconventional steps of embodiments of the present invention comprise contacting a material with a reagent comprising a thiocarbonyl group and other reagents.

[0217] As used herein, the words “comprising” (and any form thereof, such as “comprise" and “comprises”), “having” (and any form thereof, such as “have” and “has”), “including” (and any form thereof, such as “include” and “includes”) or “containing” (and any form thereof, such as “contain” and “contains”), are inclusive or open-ended and do not exclude additional, unrecited elements or process / method steps.

[0218] The term of degree “substantially” as used herein means a reasonable amount of deviation of the modified term such that the end result is not significantly changed. These terms of degree should be construed as including a deviation of at least ±5% of the modified term if this deviation would not negate the meaning of the term it modifies. Note that in the specification and claims, “about” or “approximately” means within twenty percent (20%) of the numerical amount cited.

[0219] As used in this application, the singular forms “a”, “an” and “the” include plural references unless the content clearly dictates otherwise.

[0220] The term “and / or” as used herein means that the listed items are present, or used, individually or in combination. In effect, this term means that “at least one of’ or “one or more” of the listed items is present or used.

[0221] Any of the above embodiments may be used in combination with, or may comprise, a reagent comprising a thiocarbonyl.

[0222] Although the invention has been described in detail with particular reference to these embodiments, other embodiments can achieve the same results. Variations and modifications of the present invention will be obvious to those skilled in the art. The entire disclosures of all references, applications, patents, and publications cited above are hereby incorporated by reference.

Claims

CLAIMSWhat is claimed is:

1. A method of recovering a base metal from a material comprising the base metal, the method comprising: contacting the material under acidic conditions with a reagent comprising a thiocarbonyl functional group, a microbe, and a growth agent; and recovering the base metal from the material comprising the base metal.

2. The method of claim 1 further comprising generating sulfate.

3. The method of claim 2 further comprising maintaining a sulfate below a threshold concentration.

4. The method of claim 3 wherein the threshold concentration is about 200 g / L to about 100 g / L.

5. The method of claim 1 wherein the growth agent comprises a yeast extract.

6. The method of claim 5 wherein the growth agent comprises a bacterium.

7. The method of claim 5 wherein the growth agent comprises a plasmid.

8. The method of claim 5 wherein the growth agent comprises an antibiotic.

9. The method of claim 5 wherein the growth agent comprises a growth factor.

10. The method of claim 1 wherein the microbe is an oxidizing microbe.11 . The method of claim 1 further comprising oxidizing a sulfur compound with the microbe.

12. The method of claim 1 wherein the microbe is a bacteria.

13. The method of claim 1 further comprising contacting the material with an oxidant.

14. The method of claim 1 further comprising contacting the material with a halide.

15. The method of claim 1 further comprising contacting the material with carbonaceous matter.

16. The method of claim 1 further comprising contacting the material with a wetting agent.

17. The method of claim 1 further comprising contacting the material with a cosolvent.

18. The method of claim 1 wherein the reagent comprising a thiocarbonyl functional group is at a concentration of about 0.001 mM to about 100 mM.

19. The method of claim 1 further comprising recovering the base metal by solvent extraction and electrowinning.

20. The method of claim 1 wherein the reagent does not complex / precipitate with the base metal.21 . A method of recovering a base metal from a material comprising the base metal, the method comprising: obtaining mineral composition data from a localized area; identifying a location of a recoverable base metal-bearing material using data from the material from the localized area; distributing a solution comprising a reagent comprising a thiocarbonyl functional group to the location of the recoverable base metal-bearing material; and recovering the base metal from the solution.

22. The method of claim 21 wherein the mineral composition data comprises data related to a passivated mineral.

23. The method of claim 21 wherein obtaining mineral composition data comprises using an analytical process.

24. The method of claim 23 wherein the analytical process comprises a test for a metal concentration.

25. The method of claim 23 wherein the analytical process comprises a test for Eh.

26. The method of claim 23 wherein the analytical process comprises a test for pH.

27. The method of claim 21 wherein identifying a location of a recoverable base metalbearing material comprises use of a heap ore map.

28. The method of claim 27 further comprising determining x,y,z coordinates for the identified location of a material.

29. The method of claim 21 wherein distributing a solution comprising a reagent comprising a thiocarbonyl functional group comprises use of an acidic solution metering system.

30. The method of claim 29 wherein the acidic solution metering system comprises a plurality of acidic solution regulating modules.31 . The method of claim 29 wherein the acidic solution metering system comprises a meter configured to detect a pressure or a flow rate of the acidic solution.

32. The method of claim 21 further comprising at least partially disposing a subsurface acidic solution distribution system into, or in proximity to, the identified location.

33. The method of claim 21 further comprising contacting the material with an oxidant.

34. The method of claim 21 further comprising contacting the material with a halide.

35. The method of claim 21 further comprising contacting the material with carbonaceous matter.

36. The method of claim 21 further comprising contacting the material with a wetting agent.

37. The method of claim 21 further comprising contacting the material with a cosolvent.

38. The method of claim 21 wherein the reagent comprising a thiocarbonyl functional group is at a concentration of about 0.001 mM to about 100 mM.

39. The method of claim 21 further comprising recovering the base metal by solvent extraction and electrowinning.

40. The method of claim 21 wherein the reagent does not complex / precipitate with the base metal.41 . A method of recovering zinc and copper from a material comprising zinc and copper, the method comprising: contacting the material under acidic conditions with a reagent comprising a thiocarbonyl functional group; and recovering zinc and copper from the material.

42. The method of claim 41 wherein the recovering of the zinc and copper is simultaneous.

43. The method of claim 41 wherein the recovering of the zinc and copper is sequential.

44. The method of claim 41 further comprising contacting the material with an oxidant.

45. The method of claim 44 wherein the oxidant comprises ferric sulfate.

46. The method of claim 41 wherein the acidic conditions comprise an acidic solution.

47. The method of claim 46 wherein the acidic solution comprises sulfuric acid.

48. The method of claim 41 further comprising contacting the material with a halide.

49. The method of claim 48 wherein the halide comprises chloride.

50. The method of claim 48 wherein the halide comprises iodide.51 . The method of claim 48 wherein the halide comprises bromide.

52. The method of claim 41 wherein the reagent comprising a thiocarbonyl functional group comprises thiourea.

53. The method of claim 41 wherein the reagent comprising a thiocarbonyl functional group comprises ethylene thiourea.

54. The method of claim 41 wherein the reagent comprising a thiocarbonyl functional group comprises thiosemicarbazide.

55. The method of claim 41 further comprising contacting the material with carbonaceous matter.

56. The method of claim 41 further comprising contacting the material with a wetting agent.

57. The method of claim 41 further comprising contacting the material with a cosolvent.

58. The method of claim 41 wherein the reagent comprising a thiocarbonyl functional group is at a concentration of about 0.001 mM to about 100 mM.

59. The method of claim 41 further comprising recovering the base metal by solvent extraction and electrowinning.

60. The method of claim 41 wherein the reagent does not complex / precipitate with the base metal.61 . A method of recovering a base metal from a material comprising the base metal, the method comprising: contacting the material with an acidic solution comprising a reagent comprising a thiocarbonyl functional group, elemental sulfur, and an acid to produce a pregnant leach solution comprising sulfate and the base metal; and recovering the base metal from the pregnant leach solution.

62. The method of claim 61 wherein the elemental sulfur is added.

63. The method of claim 61 wherein the elemental sulfur is a byproduct of a sulfidic material.

64. The method of claim 61 wherein the elemental sulfur is endogenous to the material.

65. The method of claim 61 wherein the elemental sulfur accelerates the production of sulfate.

66. The method of claim 61 further comprising agglomerating the material.

67. The method of claim 66 further comprising agglomerating the material with sulfidic waste.

68. The method of claim 61 wherein the initial sulfate concentration in the material is 0.001 g / L to about 20 g / L.

69. The method of claim 61 wherein the acidic solution comprises a sulfide-containing additive.

70. The method of claim 61 wherein the material comprises pyrite.71 . The method of claim 61 wherein the acid is sulfuric acid.

72. The method of claim 61 further comprising controlling the sulfate concentration.

73. The method of claim 61 further comprising contacting the material with an oxidant.

74. The method of claim 61 further comprising contacting the material with a halide.

75. The method of claim 61 further comprising contacting the material with carbonaceous matter.

76. The method of claim 61 further comprising contacting the material with a wetting agent.

77. The method of claim 61 further comprising contacting the material with a cosolvent.

78. The method of claim 61 wherein the reagent comprising a thiocarbonyl functional group is at a concentration of about 0.001 mM to about 100 mM.

79. The method of claim 61 further comprising recovering the base metal by solvent extraction and electrowinning.

80. The method of claim 61 wherein the reagent does not complex / precipitate with the base metal.81 . A method of recovering a base metal from a material comprising the base metal, the method comprising: contacting the material under acidic conditions with a reagent comprising a thiocarbonyl functional group and added pyrite; and recovering the base metal from the material comprising the base metal.

82. The method of claim 81 wherein the pyrite is a solid.

83. The method of claim 81 wherein the pyrite is part of a solution.

84. The method of claim 81 further comprising agglomerating the pyrite with the material.

85. The method of claim 84 wherein the pyrite is 0.1 wt% to about 25 wt% of the mass of the agglomerate.

86. The method of claim 84 wherein the pyrite is about 0.1 wt% of the mass of the agglomerate.

87. The method of claim 81 wherein the pyrite is 1 wt% to about 20 wt% of the mass of the agglomerate.

88. The method of claim 81 wherein the pyrite is 10 wt% to about 15 wt% of the mass of the agglomerate.

89. The method of claim 81 wherein the pyrite comprises a particle size of about a P80 of 1 mm.

90. The method of claim 81 wherein the pyrite comprises a particle size of less than 1 mm.91 . The method of claim 81 wherein the pyrite comprises a particle size of less than 250 pm.

92. The method of claim 81 wherein the pyrite comprises a particle size of about a p80 of 250 pm.

93. The method of claim 81 further comprising contacting the material with an oxidant.

94. The method of claim 81 further comprising contacting the material with a halide.

95. The method of claim 81 further comprising contacting the material with carbonaceous matter.

96. The method of claim 81 further comprising contacting the material with a wetting agent.

97. The method of claim 81 further comprising contacting the material with a cosolvent.

98. The method of claim 81 wherein the reagent comprising a thiocarbonyl functional group is at a concentration of about 0.001 mM to about 100 mM.

99. The method of claim 81 further comprising recovering the base metal by solvent extraction and electrowinning.

100. The method of claim 81 wherein the reagent does not complex / precipitate with the base metal.101 . A method of re-passivating a material comprising a base metal sulfide that has been de-passivated by contact with a reagent comprising a thiocarbonyl functional group, the method comprising removing the reagent comprising a thiocarbonyl functional group from the material to allow formation of a passivation layer on the material.

102. A method of reversibly de-passivating a material comprising a base-metal sulfide, the method comprising: contacting the material with an acidic solution comprising a reagent comprising a thiocarbonyl functional group to remove a passivation layer on the material; and removing the reagent comprising a thiocarbonyl function group from the material to allow formation of a further passivation layer on the material.

103. The method of claim 102, further comprising contacting the material with an acidic solution comprising a reagent comprising a thiocarbonyl functional group to remove the further passivation layer from the material.

104. A method of obtaining a base metal, the method comprising recovering a base metal from a material that has been re-passivated according to the method of claim 101 or 102.

105. The method of claim 104, wherein recovering the base metal from the material comprises: contacting the material with an acidic solution comprising a reagent comprising a thiocarbonyl functional group to produce a pregnant leach solution comprising the base metal; recovering the base metal from the pregnant leach solution.

102. The method of claim 101 further comprising forming an additional chemical substance.

103. The method of claim 102 wherein the additional chemical substance is a byproduct.

104. The method of claim 102 wherein the additional chemical substance is a reaction product.

105. The method of claim 102 wherein the additional chemical substance comprises formamidine disulfide.

106. The method of claim 102 wherein the additional chemical substance comprises elemental sulfur.

107. The method of claim 102 further comprising recirculating the additional chemical substance through a raffinate pond.

108. The method of claim 102 further comprising routing the reagent comprising the thiocarbonyl and / or the additional chemical substance to a solvent extraction circuit.

109. The method of claim 102 further comprising separating the reagent comprising the thiocarbonyl and / or the additional chemical substance out of the acidic solution.

110. The method of claim 101 wherein the reagent comprising the thiocarbonyl functional group disrupts the passivation layer.

111. The method of claim 110 wherein the reagent comprising the thiocarbonyl reacts with a base metal sulfide after disrupting the passivation layer.

112. The method of claim 101 wherein the reagent comprising the thiocarbonyl functional group allows the extraction of a base metal from a base metal sulfide.

113. The method of claim 101 further comprising contacting the material with an oxidant.

114. The method of claim 101 further comprising contacting the material with a halide.

115. The method of claim 101 further comprising contacting the material with carbonaceous matter.

116. The method of claim 101 further comprising contacting the material with a wetting agent.

117. The method of claim 101 further comprising contacting the material with a cosolvent.

118. The method of claim 101 wherein the reagent comprising a thiocarbonyl functional group is at a concentration of about 0.002 mM to about 100 mM.

119. The method of claim 101 further comprising recovering the base metal by solvent extraction and electrowinning.

120. The method of claim 101 wherein the reagent does not complex / precipitate with the base metal.121 . A method of recovering a base metal from a material comprising the base metal, the method comprising: forming the material into particles comprising a size and / or shape optimal for base metal recovery from the material under acidic conditions with a reagent comprising a thiocarbonyl functional group; contacting the material under acidic conditions with a reagent comprising a thiocarbonyl functional group; and recovering the base metal from the material comprising the base metal.

122. The method of claim 121 wherein forming the material into particles comprises ablating the material.

123. The method of claim 122 wherein ablating the material comprises contacting a first portion of material against a second portion of material.

124. The method of claim 121 wherein forming the material into particles comprises grinding.

125. The method of claim 124 wherein grinding comprises use of a semi-autogenous grinding mill.

126. The method of claim 125 further comprising ball mill grinding.

127. The method of claim 125 further comprising rod mill grinding.

128. The method of claim 121 wherein forming the material into particles comprises crushing.

129. The method of claim 121 wherein forming the material into particles comprises milling.

130. The method of claim 121 wherein forming the material into particles comprises comminuting.

131. The method of claim 121 further comprising forming the material into particles in the presence of copper powder.

132. The method of claim 121 further comprising selectively removing particles not comprising the base metal from particles comprising the base metal.

133. The method of claim 121 further comprising contacting the material with an oxidant.

134. The method of claim 121 further comprising contacting the material with a halide.

135. The method of claim 121 further comprising contacting the material with carbonaceous matter.

136. The method of claim 121 further comprising contacting the material with a wetting agent.

137. The method of claim 121 further comprising contacting the material with a cosolvent.

138. The method of claim 121 wherein the reagent comprising a thiocarbonyl functional group is at a concentration of about 0.001 mM to about 100 mM.

139. The method of claim 121 further comprising recovering the base metal by solvent extraction and electrowinning.

140. The method of claim 121 wherein the reagent does not complex / precipitate with the base metal.

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