Development of a Mutant Strain of Thiobacillus ferrooxidans and Optimisation of some Physical Parameters for Desulfurization of Indian Coal

A mutant strain of Thiobacillus ferrooxidans X₂₀₀ was incubated with samples of coal taken from Assam, India. Mutation resulted in a greater amount of desulfurization (30-32%) against the parent strain (9.9-14%). Influence of leaching parameters such as ore concentration (pulp density), particle size, initial pH of the medium, temperature, volume of medium in 250 ml conical flask, inoculum concentration and age of the inoculum was studied. Optimum particle size was 150 to 200 mesh, optimum pulp density was 2%, initial pH of the medium was 6.0, optimum volume of fermentation medium was 50 ml, time period of incubation was 8 days, inoculum volume was 5.0 ml and age of inoculum, 7 days. The maximum desulfurization of coal by using these physical parameters was 55%.