Recovery of silver from chloride leach solutions by iodide precipitation.
Carnahan TG; Flynn CM Jr.; Lindstrom RF
Reno, NV: U.S. Department of the Interior, Bureau of Mines, RI 8428, 1980 Jan; :1-9
The federal Bureau of Mines investigated, on a laboratory scale, a technique for recovery of silver from pregnant solutions generated in the hydrometallurgical treatment of complex base-metal sulfide concentrates with oxidizing chloride media. This technique provides a means for recovery and simplified reduction of accessory silver to metal from chloride solutions. The method consists of adding nai or ki to the solution to precipitate agi, which is then contacted with na2s to produce ag2s and to regenerate the iodide salt solution. Silver recoveries range from 99 pct with 20 pct excess iodide precipitant, to 92 pct when the theoretical stoichiometric amount of precipitant is employed. The ag2s product can be reduced to silver metal by contact with aluminum chips in naoh solution followed by purification with conventional fire refining techniques.
Concentration (Composition); Flocculation; Hydrometallurgy; Leaching; Performance evaluation; Pollution control; Precipitation (Chemistry); Separation; Silver
IH; Report of Investigations
NTIS Accession No.
Reno, NV: U.S. Department of the Interior, Bureau of Mines, RI 8428