Microorganisms for nickel laterite leaching
Due to depletion of nickel sulfide ores, the development of new processes for the expansion of usage of laterites which contain up to 70％ of the worlds nickel in industry is a topical issue. A widespread type of nickel silicates is limonitesaprolite poor ore with less than 1. 0％ nickel. Nowadays this type of ore is not processed because of the high consumption of sulfuric acid due to the considerable quantity of magnesium. According to literature review, the application of microorganisms, for example, Aspergillus niger and Penicillium fungi, allows a decrease in acid consumption as a result of the organic acid production by these microorganisms, but nickel recovery is not significant. The action mechanisms of Jarrowia lipolytica yeast, Aspergillus niger and Penicillium fungi are carried out as effective acid producers. The Clostridium genus bacteria liberated from the limonite-saprolite ore acquired from Norilsk Nickel was studied in comparison with the Bacillus genus bacteria for nickel laterite bioleaching. The influence of temperature, acidity, redox potential, mixing, content and mode of change of nutrient are investigated. Also features of the mineral interaction with produced acids and enzymes and properties of microorganisms to sorb elements from solution and grow on a mineral substratum are considered. By changing the chemical and mineral structure of silicate nickel ore, various actions of the investigated microorganisms are shown. Through the biodestruction of silicate bonds metals are recovered and ore is enriched. The effect of a decreased electrochemical potential in the negative area is established for the interaction of bacteria and silicate nickel ore. The dependence between Bacillus genes bacteria action efficiency and type of layered nickel silicates crystal structure is revealed. The application of the studied cultures of bacteria for nickel laterite leaching allows a decrease in acid consumption of 13％ and increase in nickel recovery of 5％ from the investigated ore due to metals recovery by the biodestruction of silicate bonds in the crystal lattice of silicates.
nickel laterite bioleaching microorganisms fungi yeast silicate bacteria silicate mineral destruction carbon acids silicaza organic silicon
Ekaterina A. Kim Lyubov N. Krylova Eduard V. Adamov
National University of Science and Technology (MISIS), 119049, Moscow, Russia
国际会议
The 19th International Biohydrometallurgy Symposium(第19届国际生物湿法冶金大会 IBS2011)
长沙
英文
604-608
2011-09-18（万方平台首次上网日期，不代表论文的发表时间）