Recovery of Copper Powder from Polluting Industrial Waste through Lively Bioleaching

An experiment of lively biohydrometallurgical leaching of worn-out hydrogenation catalysts in an aerobic batch system with Thiobacillus ferrooxidans is carried out for process parameters optimization. The maximum bioleaching of worn-out catalysts is noticed at 74.85% (w/w) and 71.50% (w/w) for 25 kg Cu/m3 and 30 kg Cu/m3 initial concentration of 200 to 240 μm waste mesh size in 192 h with pH 2.5 and temperature 35°C, respectively. The optimum shaking speed is noticed as 60 rpm. All results are noted after subtraction of leaching in control conditions. Seven days age-old and 20% (v/v) innoculum culture is used in the present study. The dissolved copper was precipitated by the precipitation using metallic iron splinter. The copper powder obtained was characterized by chemical and physical methods.