Studies on biohydrometallurgical leaching of iron sulphide ore using <i style="">Thiobacillus ferrooxidans</i>

Abstract

Biohydrometallurgical leaching of iron sulphide ore in an aerobic batch system using bacteria <i style="">Thiobacillus ferrooxidans</i> has been studied for process parameters optimization. The maximum bioleaching of Fe²⁺ is 79.88 and 79.10 per cent <i style="">(w/w)</i> for 25 and 30 kg/m³ initial ferrous iron loading at optimum conditions. The optimum parameters are—time 172 h, pH 2.5 and temperature 35°C. The optimum glucose and nitrogen (as ammonium sulphate) concentration for maximum bacterial bioleaching is 3.0 and 0.30 per cent (<i style="">w/w</i>) respectively. The optimum shaking speed (rpm) is 60. 20 percent <i style="">(v/v)</i> and 7 days age-old suspension culture was used for the studies. The bacteria can tolerate upto 35 kg/m³ initial ferrous iron concentration.