Enhanced Leaching of Refractory Ag and Ag-Sb-Cu Sulphide Minerals: Kinetics and Surface Chemistry-Latest Developments
In the last 4 years, the high price of silver attracted more interest for improving its extraction.Metallic silver and silver minerals require a high concentration of cyanide and show slow leaching rates and poor extraction. This investigation determined the effects of dissolved oxygen, lead nitrate and a pretreatment on silver leaching from slurry containing quartz mixed with metallic silver and high purity acanthite. Stephanite, pyrargyrite and polybasite were also used in the study. The silver minerals were characterized by chemical assay, X-ray diffraction analysis (XRD), image analysis (MP-SEM-IPS) and electron microprobe analysis (EMPA). Increased dissolved oxygen of the slurry produced the fastest silver leaching kinetics. The leaching of silver from high purity acanthite was determined under various conditions and compared to a new process called CANMET Enhanced Leaching Process (CELP). For a slurry containing acanthite, a 23% improvement (from 76% to 99%) in silver extraction was obtained with the CELP. In presence of pyrargyrite and polybasite, silver extraction increased from 75% to 90% and 86% to 99% respectively using the CELP. No improvement was obtained for the slurry with stephanite (99% extraction in 72 hours). However, the sliver leaching rate was much faster with the CELP. XPS analysis of individual silver mineral particles showed that CELP leached surfaces were considerably more oxidized relative to the conventional cyanidation leached surfaces. Leaching of two gold/silver ores indicated that the efficiency of the CELP increased with the refractoriness of the sample. Gold extractions were comparable for the two technologies while silver extraction improved up to 5% (70g/t) for the CELP. The final leach solutions contained lower concentrations of copper, which consequently reduces the effluent treatment costs.
Gold Silver Cyanide Extraction Leaching CELP
G. Desch(e)nes M. Fulton C. Xia A. Pratt H. Guo
Mining and Mineral Sciences Laboratories, CANMET, Natural Resources Canada, Canada Wardrop Engineering Inc., Canada
国际会议
XXIV International Mineral Processing Congress(第24届国际矿物加工大会)
北京
英文
1642-1652
2008-09-24（万方平台首次上网日期，不代表论文的发表时间）