Effect of Particle Size on the Column Bioleaching of Tibet Yulong Copper Ore

This study aimed to investigate the effect of ore particle size on the bioleaching of Yulong copper ore in the bench-scale columns using the mixed culture of moderately thermophilic microorganisms. Bioleaching experiments were carried out on particle sizes of 5-10, 10-15 and 15-25mm in the same kind of column reactors. In the control test of acid leaching, the column reactor was charged with the middle particle size (10-15mm). The results indicated that copper extraction in the column reactor with particle size of 5-10 mm was highest among the three particle sizes. After 110-days leaching, 89% of copper was leached at 5-10 mm particle size while 57% was extracted at 15-25 mm particle size and 80% at 10-15 mm. Under the same particle size (10-15 mm), copper recovery in the column reactor with inoculation of microorganisms was 25% higher in comparison to the control test of acid leaching, while sulfuric acid consumption was 33% less than that.