Abstract: System for, and methods of, recovering precious metals from precious metals-containing solids are described herein. Methods for the recovery of precious metals from precious metals-containing solids heating a salt mixture to form a molten salt mixture, adding a precious metals-containing solid to the molten salt mixture to form a molten salt/precious metals-containing solids mixture, adding an oxidizing agent to the molten salt/precious metals-containing solids mixture, forming a liquid solution from molten salt/precious metals-containing solids mixture, the liquid solution comprising soluble precious metal salts, and subjecting the liquid solution to an electrodeposition process to form purified precious metals. Systems for, and methods of, recovery precious metals from precious metals-containing solids allow for the recovery of salt mixtures and reuse of the salt mixtures in subsequent precious metals recovery operations.

Abstract: An environmentally friendly (e.g. no acid, base, or cyanide) system and process for large scale extraction of metal ion into aerobic molten salt (or ionic liquid) and the electrodeposition of metal (e.g. copper, gold, silver, etc.) from the metal ion dissolved in the molten salt. The non-volatile low vapor pressure liquid salt is reusable, and heat from the molten slag can heat the molten salts or ionic liquids. Another embodiment comprises a one-pot apparatus for the extraction of metal (e.g. copper) from metal earths and electrodepositing the metal using a low melting (209° C.) aerated Na—K—Zn chloride salt in which copper metal oxidizes and is converted to soluble copper chloride. When an electrical power supply is connected to the graphite vessel (cathode) and to copper rods in the melt (anodes), then the copper chloride is deposited as copper metal by electroreduction on the bottom of the graphite reaction vessel.

Abstract: The method of recovering copper from sulfide ores with copper and iron, comprises the steps of reacting, in a reaction vessel, a copper-containing sulfide ore with sulfur dioxide gas to form elemental sulfur, an iron oxide and a copper sulfide, separating the solids comprising the iron oxide and copper sulfate from a liquid phase of the reaction mixture, leaching the dried solids with an aqueous solution comprising water or dilute sulfuric acid and solubilizing the copper sulfate, and recovering copper from the solubilized copper sulfate.

Abstract: Method of producing hydrogen sulfide in an alkaline environment. A mixture having a sodium salt, elemental sulfur (S) and water is added to a reactor for the purpose of generating hydrogen sulfide (H2S) gas as the main product and sodium sulfate (Na2SO4) as a byproduct.