Feasibility study on the microbial separation of iron from slime

Abstract

Bio-mineral processing is the generic term that describes the processing of metal containing ores, concentrator tailings, newly mined run-of-the-mine (ROM) material, and intermediate to high-grade ores using (micro-) biological technology. The slime generated by the Tata Iron and Steel Company is becoming a major problem for the Company. Since, it contains a high quantity of Iron (around 56%), it can be recycled for the generation of Steel. Bioleaching comes to the rescue of such a problem. As it contains a high percentage of alumina and silica as its component, it can be treated as a non- sulphide system. Heterotrophic organisms can be used to leach out the alumina and silica. We have thus tried to see the feasibility of Bacillus to leach the slime and increase the Iron content in it. The conditions like pH, time and inoculum size have been optimized. The results showed that, there was a maximum recovery of iron (around 79%) in the slime and the optimum conditions at which this was obtained were at pH of 7, a time of 5 days and inoculum size of 20%.