Carbon-in-pulp Silver Adsorption from Cyanide Leach Slurries of a Silver Ore.
Hussey-SJ; Salisbury-HB; Potter-GM
NTIS: PB 279 681 :22 pages
The Bureau of Mines investigated the applicability of carbon-in-pulp process for recovering silver from low-grade ores. The reasons for the research were to illustrate a practical procedure for the process design of carbon-in-pulp adsorption circuits using leach slurries and simple equipment, and to illustrate how equations of adsorption theory relating to rate data and equilibrium adsorption curves can be helpful in process design. Carbon-in-pulp silver adsorption tests were made on banner, Idaho, mine-run ore samples with silver contents ranging from 2.0 to 8.5 Oz/ton and variations in cyanide leach extraction from 48 to 93 pct. The lower recoveries were attributed to the presence of complex silver sulfide minerals. Carbon-in-pulp batch adsorption tests provided rate data for the estimation of a silver equilibrium adsorption curve. Process design procedures in which the rate data were related to an equilibrium adsorption survey by equations of adsorption theory were used to plan a four-stage pilot plant cascade. The pilot plant was successfully operated for 45 hr of countercurrent flow, producing a carbon product containing a mean silver loading of 571 oz/ton from a pregnant solution of 1.7 Oz/ton of silver. Virtually all of the dissolved silver was recovered on the carbon.
IH; Report of Investigation;
NTIS Accession No.
NTIS: PB 279 681