Desorption of gold from activated carbon

Gold is desorbed from activated carbon by contacting, at a temperature of about 70° to 160° 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.

Separate recovery of silver and gold from cyanide solutions

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.

Leaching agglomerated gold - silver ores

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.

Leaching agglomerated gold - silver ores

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.

Leaching gold - silver ores

ABSTRACT Percolation leaching of gold or silver ores, tailings or wastes is accomplished by a process comprisng intial agglo-meration 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.

IMPROVED METHOD FOR LEACHING OF MINERALS, GLUES OR WASTE MATERIALS CONTAINING GOLD AND / OR SILVER VALUES

Chemical mining of copper porphyry ores

Copper porphyry ores, especially those too deeply buried for conventional open pit mining, are mined in place by an in situ leaching technique using as a leaching medium a mixture of dilute sulfuric acid, oxygen and an alkali metal or ammonium chloride salt. The chloride ion speeds dissolution of copper minerals, especially chalcopyrite, and the alkali metal or ammonium ion reacts with iron and sulfate in the leaching medium to deposit iron in the form of crystalline jarosites. Precipitation of iron within the ore body as a jarosite maintains the permeability of the ore body to the leaching medium thus increasing both the rate and the total recovery of copper as well as depleting the leach solution of unwanted iron.

Desorption of gold from activated carbon

ABSTRACT OF THE DISCLOSURE Gold and/or silver are desorbed from activated carbon by contacting, at a temperature of about 80 to 160°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.

Method for electrowinning molybdenum from molten electrolytes