A process for recovery of one or more elements, selected from precious metals and chalcophile metals, as herein defined, from materials containing precious and/or chalcophile metal/s, said process including: (i) contacting the material with an alkaline solution containing a lixiviant comprising an amino acid, or derivative thereof, and an alkali stable transition metal complex in order to form a leachate containing the precious metal and/or chalcophile metal; and (ii) recovering the precious metal and/or chalcophile metal from the leachate.

A process for the recovery of gold from carbon fines waste, which are produced, especially from carbon-in-leach (CIL) and carbon-in-pulp (CIP) processes. The gold may be eluted from carbon fines with alkaline eluent having a low oxidation reduction potential (ORP). Value added products may be obtained from the extracted carbon fines.

Adducts, superstructures, and crystalline compositions prepared from a metal halide anion non-covalently bound to the outer surface of a macrocycle and methods for gold recovery are disclosed.

An activated carbon regeneration method of the present invention is for eluting gold from activated carbon on which the gold has been adsorbed and thereafter recycling, in adsorption of the gold, the used activated carbon from which the gold has been eluted, the method including: washing the used activated carbon with an acidic washing liquid, alkaline washing liquid or neutral washing liquid; and when the used activated carbon is washed with the acidic washing liquid, keeping the acidic washing liquid after the washing in an acidic region, or when the used activated carbon is washed with the alkaline washing liquid or neutral washing liquid, keeping the alkaline washing liquid or neutral washing liquid after the washing in an alkaline region or neutral region.

Materials and methods for precious metal recovery are disclosed. Usable leaching solutions are preferably aqueous based and include appropriate materials in sufficient quantities to solubilize and stabilize precious metal. Such materials typically include oxidant material. Some or all of the oxidant material can be, in some instances, generated in-situ. The leaching solution is typically contacted with a substrate having a target precious metal, thereby solubilizing precious metal to form a stable, pregnant solution. The precious metal can then be recovered from the pregnant solution. In some instances, components of the leaching solution can be regenerated and reused in subsequent leaching.

A method for extracting palladium includes: (1) mixing a palladium-containing material with nitric acid and an alkali metal ion-containing catalyst to obtain a mixed solution, heating the mixed solution, and removing a resulting residue to obtain a palladium-containing leaching liquor; and (2) subjecting the palladium-containing leaching liquor obtained in step (1) to separative extraction to obtain metallic palladium or at least one palladium-containing product, and reusing a residual solution for step (1) in a subsequent extraction. The alkali metal ion-containing catalyst of the present disclosure can leach palladium at a higher rate than that when pure nitric acid of the same concentration is used and does not volatilize, such that the recycling of a mother liquor can be realized. The method involves simple operations, has low production costs, greatly shortens the palladium extraction time, does not lead to secondary pollution, and meets the requirements of environmental protection.

A process for leaching minerals that contain metal sulphides and one or more precious metals or precious metal compounds, the process comprising the steps of a first leaching step to leach the minerals under oxidative conditions at a pH of less than 4 to form a slurry or pulp, the slurry or pulp comprising a solid phase containing unreacted components, solid reaction products and elemental sulphur, and subjecting the slurry or pulp or solid residue from the first leaching step to a second leaching step comprising oxidative leaching at pH of at least 9.0 to thereby form thiosulphate, whereby the thiosulphate leaches precious metal from the solid residue.

The present invention is intended for effectively removing copper, iron, sulfur, which are impurities, from activated carbon on which gold is adsorbed before gold eluting in the point of view of gold recovery, and is related to a method for eluting gold from an activated carbon on which at least sulfur (S) and gold (Au) are adsorbed, whereas the activated carbon is washed with an alkali solution before eluting the gold, and then the gold is eluted from the activated carbon.

In a method for recovering a copper sulfide concentrate by froth flotation from an ore containing an iron sulfide, wet grinding of the ore with grinding media made of high chromium cast iron alloy having a chromium content of from 10 to 35% by weight is combined with an addition of hydrogen peroxide to the conditioned mineral pulp before or during flotation in order to improve concentrate grade and recovery of copper sulfides.

A method for recovering one or more of copper, uranium and a precious metal from an ore material, including: (a) forming a heap of the ore material; (b) during active heap irrigation, contacting the heap of the ore material with an iron containing acidic leach liquor having a high chloride content in the presence of an oxygen containing gas, and producing a pregnant leach solution; and (c) recovering one or more of copper, uranium and a precious metal from the pregnant leach solution.