Mercury Production from Sulphide Concentrates by Cupric Chloride Leaching and Aqueous Electrolysis.
Murphy-JE; Henry-HG; Eisele-JA
Ch in Sulphide Deposits--their Origin & Processing Inst Min and Metall PP 283-288 :283-288
The U.S. Bureau of Mines developed a hydrometallurgical method for treating mercury sulfide concentrates to recover mercury. Sulfide flotation concentrate from the McDermitt Mine (Nevada) was leached in a cupric chloride solution at 80 deg c. The cupric chloride concentration of the solution was maintained during leaching by chlorine sparging. Mercury extractions exceeded 99 pct in 3 h of leaching. After leaching, the ph of the solution was increased from 1 to 4.5 To precipitate copper as atacamite. The pregnant solution, which typically contained 100 g/l hg, was sent to electrolysis to produce high-purity mercury metal and chlorine for recycle. In a 200-a electrolytic cell operated for 24 h, current efficiency was 99 pct, and the energy requirement was 2 kw.H/kg of mercury produced. Mercury removal from the waste stream was also investigated. Iron or zinc cementation, sulfide precipitation with h2s, and activated carbon adsorption all decreased the mercury concentration from 10 g/l to 0.01 Mg/l.
Ch. in Sulphide Deposits--their Origin & Processing. Inst. Min. and Metall., PP. 283-288