Abstract: A method for the separation of bismuth from a complex chloride solution obtained by leaching with chloride reagents ores containing bismuth and high concentrations of other metals comprising adding to said complex chloride solution at least a stoichiometric amount of a precipitating agent selected from the group consisting of hexamminecobalt (III) salts and hexamminechromium (III) salts soluble in said solution to precipitate said bismuth as a hexamminecobalt (III) bismuth salt or a hexamminechromium (III) bismuth salt and separating said precipitate from said solution.

Abstract: Percolation leaching of gold or silver ores, tailings or wastes is accomplished by a process comprising initial agglomeration of fines in the feed by means of a binding agent and water, followed by aging and, subsequently, leaching to recover gold or silver values.

Abstract: A rapid, energy efficient, low cost, nonhazardous method for the selective removal of mercury from mercury-containing metal cyanide solutions, particularly the cyanide solutions resulting from the cyanidation of gold ore and the like, wherein a reactive sulfide is admixed with the solution for a time sufficient to form an insoluble mercuric sulfide precipitate. The mercuric sulfide precipitate is then separated from the metal cyanide solution by filtration or other conventional means.

Abstract: Percolation leaching of gold or silver ores, tailings or wastes is accomplished by a process comprising initial agglomeration of fines in the feed by means of a binding agent and cyanide solution, followed by aging and, subsequently, leaching to recover gold or silver values.

Abstract: Gold is desorbed from activated carbon by contacting, at a temperature of about 70.degree. to 160.degree. C., with a solution comprising about 20 to 30 percent by volume of a water soluble alcohol and about 80 to 70 percent by volume of an aqueous solution of a strong base.

Abstract: Copper and nickel are recovered from alloys by electrolysis in a cell employing the alloy as anode. In addition, the electrolytic cell has separate anode and cathode sections, with an intermediate liquid copper-mercury alloy electrode between the anode and cathode sections.

Abstract: Silver and gold are selectively recovered from cyanide solutions by addition of lime, and precipitation of the silver as sulfide by means of sodium sulfide, followed by electrowinning of gold from the filtrate.

Abstract: Copper is extracted from sulfide ores or concentrates by electrolysis in a cell having separate anode and cathode sections, and having an intermediate liquid copper-mercury alloy electrode between the anode and cathode sections.

Abstract: Copper and silver are recovered from complex sulfide ores or concentrates containing, in addition, metals such as lead, zinc, arsenic, antimony, and iron by leaching with a combination of ferrous chloride and oxygen.

Abstract: A process for recovering copper from oxidized ores by utilizing alkaline leachants having incorporated therein siliceous material to inhibit the dehydration of the formed copper complex, thereby permitting increased recovery and improved settling and filtering characteristics of the reacted slurry.

Abstract: Complex sulfide ores or concentrates are decomposed by treatment with a combination of chlorine and oxygen, the amount of chlorine being limited to that necessary to convert sulfides of the desired metals, such as zinc, lead, copper, cadmium, silver, nickel and cobalt to chlorides.

Abstract: Recovery of copper from sulfide ores is achieved by placing the ore together with a caustic soda or potash solution in a pressure vessel. An oxidizing gas is then introduced into the vessel and the temperature and pressure of the system is adjusted as required. Copper ions are freed from the crystalline structure in the form of the complex anion, Cu(OH).sub.4 .sup.=. The copper may then be recovered by reduction or precipitation as cupric oxide.