A method for extracting and enriching gold with a selenide includes: mixing an isocyanate and a selenium-containing compound of a formula of HO—R—Se—R—OH in a solvent to obtain a mixture system, where R is selected from linear or branched C.sub.2 to C.sub.11 alkylene groups; adding a tin-based catalyst into the mixture system to activate a reaction, drying the mixture system after the reaction, and obtaining a powdery selenium-containing polymer by grinding; immersing the selenium-containing polymer in an aqueous solution containing gold ions to allow gold to be extracted from the aqueous solution; and removing the selenium-containing polymer attached to a surface of extracted gold, thereby obtaining an extracted and enriched gold.

Formation of CaSO.sub.4 and Fe.sub.2O.sub.3 containing deposits is reduced in a pressure oxidation autoclave and/or adjacent circuits during pressure oxidation of gold-containing ore. The gold-containing ore is combined with water to create an aqueous slurry that is heated and introduced into the autoclave. The method includes providing a scale inhibitor that is free of an organic polymer and includes an inorganic phosphate according to formula (I), (XPO.sub.3).sub.m, wherein X is Na, K, H, or combinations thereof, and m is at least about 6, an inorganic phosphate according to formula (II), Y.sub.n+2P.sub.nO.sub.3n+1, wherein Y is Na, K, H, an organic phosphonate; or combinations thereof, and n is at least about 6. The method includes the step of combining the scale inhibitor and at least one of the gold-containing ore, the water, and the aqueous slurry to reduce scale.

Process for the production of particulate ruthenium with a purity of 99.99 wt. % and a specific surface area of 0.2-0.5 m.sup.2/g, comprising: (1) providing a hydrochloric solution prepared by dissolving RuO.sub.4 in hydrochloric acid and has a content of ruthenium in the form of dissolved ruthenium species of 15-22 wt. %; (2) providing an aqueous solution with an ammonium chloride content of 200-600 g/litre; (3) forming a reaction mixture by dosing the hydrochloric solution provided in step (1) to the aqueous solution provided in step (2) at a molar ratio of 1 mol ruthenium: 3-6 mol ammonium chloride, at a temperature of 55-90 C. over the course of 0.2-5 hours and while adjusting and maintaining a pH of 0.6 to 0; (4) separating solid material formed during step (3) from the hydrochloric reaction mixture; and (5) calcinating the solid material separated in step (4) at an object temperature of 350-1,000 C.

Embodiments disclosed herein include multilayer films that have at least two layers. More particularly, disclosed in embodiments herein are multilayer films that include at least a first layer and a second layer, wherein the first layer includes at least one polyethylene polymer, wherein the second layer includes at least one water-soluble polymer, wherein the second layer is insoluble in water at a temperature of less than 20 C., wherein the second layer is soluble in water at a temperature of 20 C. or greater, and wherein the first layer has one or more openings through the first layer to expose the second layer. Also disclosed herein are methods of using such multilayer films for extracting metal from metal ore.

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.

A method of selectively recovering palladium from a palladium-containing material comprises providing a leaching solution comprising hydrochloric acid, hydrogen peroxide, and an iron salt comprising one or both of ferric chloride or ferrous chloride and contacting a palladium-containing material with the leaching solution to dissolve palladium from the palladium-containing material. Related methods of selectively recovering palladium from a palladium-containing material are also disclosed.

The present disclosure provides a method for extracting and recovering gold from an aqueous solution, the method including: (1) gold extraction from an aqueous solution through electrocoagulation, in which an electrocoagulation reaction is performed in an electrolytic cell to produce iron hydroxide in-situ, so as to capture gold in the aqueous solution and reduces the gold into gold nanoparticles in-situ; (2) pickling and liquefaction of the precipitated iron sludge, in which the obtained precipitate is dissolved in nitric acid to dissolve iron flocs after washing treatment; and (3) separation and recovery of gold through a nanofiltration membrane system, in which the resulting solution after pickling the precipitated iron sludge is subjected to cut-off treatment using a nanofiltration membrane to separate nano-sized elemental gold from the solution, and then the resultant is washed with water to obtain elemental gold. The extraction and recovery method of the present disclosure has characteristics of high gold extraction efficiency (up to 100%), low cost, simple process, good stability and environmental protection, and can recover high-grade elemental gold (with a comprehensive recovery rate greater than 95%). The method is of an important significance for technical guidance and practical engineering application for the extraction and recovery of gold in various gold smelting and extraction processes.

The present disclosure relates to a method for recovering a metal or a metal compound, using genus Galdieria.

Discloses a hydrometallurgical process and system for the recovery of precious metals; specifically palladium, rhodium, and platinum metals, at high purity and with limited waste and environmental fouling.

Provided is a method of recovering gold, and optionally silver, from gold-bearing, and optionally silver-bearing, double refractory raw material, comprising the steps of (a) leaching the gold-bearing, and optionally silver-bearing, double refractory raw material in a chloride containing leaching solution to dissolve gold and to obtain a leach solution comprising gold, and optionally silver, in solution, whereby the redox of leaching solution in the chloride leaching step is above 550 mV vs. Ag/AgCl; and simultaneously contacting the leach solution comprising gold, and optionally silver, in solution with a re-sorptive material to obtain a gold-containing, and optionally silver-containing, re-sorptive material; and (b) recovering gold and optionally silver from the gold-containing, and optionally silver-containing, re-sorptive material.