Effect of anions on selective solubilization of zinc and copper in bacterial leaching of sulfide ores

✍ Scribed by Lesia Harahuc; Hector M. Lizama; Isamu Suzuki

• Publisher: John Wiley and Sons
• Year: 2000
• Tongue: English
• Weight: 96 KB
• Volume: 69
• Category: Article
• ISSN: 0006-3592
• DOI: 10.1002/(sici)1097-0290(20000720)69:2<196::aid-bit8>3.0.co;2-q

✦ Synopsis

Bacterial leaching of sulfide ores using Thiobacillus ferrooxidans, Thiobacillus thiooxidans, or a combi- nation of the two was studied at various concentrations of specific anions. Selective zinc and copper solubilization was obtained by inhibiting iron oxidation without affecting sulfur/sulfide oxidation. Phosphate reduced iron solubilization from a pyrite (FeS 2 )-sphalerite (ZnS) mixture without significantly affecting zinc solubilization.

Copper leaching from a chalcopyrite (CuFeS 2 )-sphalerite mixture was stimulated by phosphate, whereas chloride accelerated zinc extraction. In a complex sulfide ore containing pyrite, chalcopyrite, and sphalerite, both phosphate and chloride reduced iron solubilization and increased copper extraction, whereas only chloride stimulated zinc extraction. Maximum leaching obtained was 100% zinc and 50% copper. Time-course studies of copper and zinc solubilization suggest the possibility of selective metal recovery following treatment with specific anions.