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Selective removal of mercury from cyanide solutions.
Flynn CM Jr.; Carnahan TG; Lindstrom RE
US Pat 4,256,707 1981 Mar; :1-4
Mercury is removed from cyanide solutions, obtained by the cyanidation of gold ores, by mixing with a sulfide, preferably silver sulfide or zinc sulfide, to precipitate the mercury as insoluble HgS, which is filtered. Thus, 40 ml of a leach solution at ph 10 containing Au 20, Hg 10, Ag 10, and NaCn 500 mg/l is treated with 60 mg of Ag2S. Ninety-nine percent of the mercury from the leach solution was precipitated as HgS, which was separated by centrifugation.
Metals; Metallurgical processes; Metal compounds; Gold; Cyanide compounds; Mercury
United States Patent 4,256,707
Page last reviewed: June 10, 2022
Content source: National Institute for Occupational Safety and Health Education and Information Division