Methods of enhancing recovery of value sulfide and/or precious metal-bearing minerals from an ore containing such minerals as well as Mg-silicate, slime forming minerals, and/or clay by adding a froth phase modifier agent to the ore, and subjecting the ore to a froth flotation process performed under acidic conditions, are provided herein.

A process for recovering copper from copper sulfide minerals, the method comprising the steps of leaching copper sulfide minerals with an aqueous solution of ammonium chloride containing cupric chloride at a temperature of between about 40 C. and about 95 C. at atmospheric pressure, to produce a solution of cuprous/cupric chloride.

A process for recovery of one or more target metals, selected from precious metals and chalcophile metals as respectively herein defined, from materials containing precious and/or chalcophile metal/s, said process including: (i) leaching the metal containing material with an aqueous solution containing: a metal liberator comprising an amino acid; and a metal retainer comprising one or more of ammonia, ammonium salts, carboxylic acids, carboxylic acid salts, dicarboxylic acids, dicarboxylic acid salts, hydroxy-carboxylic acids, hydroxy-carboxylic acid salts, ethylene diamine tetra-acetic acid (EDTA) and EDTA salts, to produce a leachate containing the target metal/s; and (ii) extracting the metal from the leachate.

Described is a method of recovering a metal from a substrate having a metal sulphide, metal oxide, or combination thereof, by contacting the substrate with an aqueous oxidant to oxidize the metal sulphide to elemental sulphur and oxidized metal or convert the complex metal oxide to a metal salt, contacting the oxidized metal or simple metal oxide with ammonium hydroxide to form soluble a ammine complex of the metal to obtain a leachate and residual solids; separating the leachate from the residual solids; and recovering the metal.

Systems and methods for basic leaching are provided. In various embodiments, a method is provided comprising leaching a slurry comprising a copper bearing material and an ammonia leach medium, adding copper powder to the slurry, separating the slurry into a pregnant leach solution and solids, and performing a solvent extraction on the pregnant leach solution to produce an loaded aqueous stream.

A method for leaching copper from an oxidized copper ore, wherein at least 5% of the copper present in the oxidized copper ore is an oxidized copper compound, the method comprising the method steps of: applying an aqueous solution of a curing agent to the oxidized copper ore to produce a cured ore; forming a leach solution by applying an ammoniacal solution that has an ammonium carbonate content of less than 5 g/L to the cured ore to produce a pregnant leach solution containing copper; and passing the pregnant leach solution to a means for recovering copper.

A process for recovering non-ferrous metals from a solid matrix may include: (a) leaching the solid matrix with an aqueous-based solution containing chloride ions, ammonium ions, and Cu.sup.2+ ions, having a pH of 6.5-8.5, in a presence of oxygen, at a temperature of 100 C.-160 C. and a pressure of 150 kPa-800 kPa, so as to obtain an extraction solution comprising leached metals and solid leaching residue; (b) separating the solid leaching residue from the extraction solution; and/or (c) subjecting the extraction solution to at least one cementation so as to recover the leached metals in elemental state. The pH may be greater than or equal to 6.5 and less than or equal to 8.5. Temperature may be greater than or equal to 100 C. and less than or equal to 160 C. Pressure may be greater than or equal to 150 kPa and less than or equal to 800 kPa.

A method for the recovery of metals from a feed stream (1) containing one or more value metals, the method comprising: (i) passing the feed stream (1) to an alkaline leach (20) to form a slurry (5) including a pregnant leach liquor of soluble metal salts and a solid residue; (ii) separating the pregnant leach liquor (8) and the solid residue (7) of step (i); (iii) passing the separated pregnant leach liquor (8) of step (ii) to a solvent extraction step (42), wherein a loaded extractant (9) containing copper and nickel, and a raffinate (19) containing cobalt and lithium, are produced; (iv) recovering cobalt (24) from the raffinate (19) of step (iii); and (v) recovering lithium (38), ammonia (28) and ammonium chloride (39) from the cobalt depleted liquor (21) of step (iv).

Described is a method of recovering a metal from a substrate having a metal sulphide, metal oxide, or combination thereof, by contacting the substrate with an aqueous oxidant to oxidize the metal sulphide to elemental sulphur and oxidized metal or convert the complex metal oxide to a metal salt, contacting the oxidized metal or simple metal oxide with ammonium hydroxide to form soluble a ammine complex of the metal to obtain a leachate and residual solids; separating the leachate from the residual solids; and recovering the metal.

Various embodiments provide a process roasting a metal bearing material under oxidizing conditions to produce an oxidized metal bearing material, roasting the oxidized metal bearing material under reducing conditions to produce a roasted metal bearing material, and leaching the roasted metal bearing material in a basic medium to yield a pregnant leach solution.