Role of ore mineralogy in optimizing conditions for bioleaching low-grade complex sulphide ores

• Published in: Transactions of Nonferrous Metals Society of China Vol. 18; no. 5; pp. 1234 - 1246
• Main Authors: OLUBAMBI, P.A., NDLOVU, S., POTGIETER, J.H., BORODE, J.O.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01-10-2008; School of Chemical and Metallurgical Engineering, University of the Witwatersrand, Johannesburg, South Africa; Department of Metallurgical and Materials Engineering, Federal University of Technology, Akure, Nigeria; Department of Metallurgical and Materials Engineering, Federal University of Technology, Akure, Nigeria%School of Chemical and Metallurgical Engineering, University of the Witwatersrand, Johannesburg, South Africa
• Subjects: bioleaching; mesophiles; ore mineralogy; processing parameters; sulphide ore; 加工参数; 生物浸取; 矿物学; 硫化物矿石; processing parameters; sulphide ore; ore mineralogy; bioleaching; mesophiles
• ISSN: 1003-6326
• DOI: 10.1016/S1003-6326(08)60210-1

The role that ore mineralogy plays in understanding and optimizing the conditions favouring the bioleaching of complex sulphide ore containing high amounts of siderite was studied using mixed cultures of mesophilic bacteria, with emphasis on zinc, lead and copper recoveries. The influencing parameters investigated include particle size, stirring speed, volume of inoculum, pulp density, and pH. The results show that the mixed mesophilic cultures can extract about two and a half times the amount of zinc than copper over an equivalent period of time. The highest zinc and copper recoveries of 89.2% and 36.4% respectively are obtained at particle size of 75 lam, stirring speed of 150 r/min, pulp density of 10% （w/v）, 12% （v/v） inoculum concentration, and a pH of 1.6. Variations in elemental composition within different particle sizes resulting from the mineralogy of the ore account for the bioleaehing behaviour at varying particle sizes. The dissolution at varying pulp density, volume ofinoculum, solution pH and the low solution potential observed are also influenced by ore mineralogy.