A Microblal Pretreatment for Double Refractory Gold Ores
Microbial pretreatment of a double refractory gold ore was investigated using a white rot fungus,Coriolus versicolor (ATTC 20869) to improve gold extraction. A series of preliminary tests were conducted to determine the amenability of the ore to fungus degradation. Pulp density, temperature,pH and retention times were the process variables considered. Both a single. Stage and two-step processes were studied to establish process conditions. During the single stage process, the ore was contacted with the fungus culture (biotic) for 3weeks at 30℃ and pH 10.0. For the two-step process,the fast step involves ore contact with the culture medium (abiotic) at 45℃ and pH 10.0 followed by fungal contact (biotic) at 30℃. Results indicated that carbonaceous matter is not degraded but passivated by the fungus; as preg-robbing activities dropped significantly from 18.1% to below 1.0%. The single stage process resulted in higher gold recovery than the two-step process Gold extraction by cyanidation of the pretreated ore was 78.9% for the single stage compared with 15.0% for the untreated ore. In the two-step process, only 73.3% gold extraction was achieved. Application of the two step process conditions to a high grade flotation concentrate, resulted in 93.3% gold extraction as against untreated concentrate of 30.5%. The results show that the microbial pretreatment process degraded sulfide sulfur, passivated carbonaceous matter and enhanced gold extraction from double refractory gold ore and concentrate.
Gold ores Fungus Biooxidation Cyanidation Preg-robbing
J. K. Afidenyo W. T. Yen R. K. Amankwah J. A. Ramsay
Mining Engineering Department, Queens University, Kingston, Ontario, Canada University of Mines and Technology, Tarkwa,Ghana Chemical Engineering Department, Queens University, Kingston, Ontario, 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
2676-2683
2008-09-24（万方平台首次上网日期，不代表论文的发表时间）