Particle size effects in bioleaching of low grade copper ore

The effect of mineral paricle size on the copper bioleaching by Acidithiobacilus have been studied.Increasing the particle size from 0.15 mm to 3.4 mm enhanced the copper recovery from 51% to 93%. While the copper recovery of finely ground particles (<0.15 mm) was76 %. Also increasing the particle size between 3.4-6 mm adversely influenced the activity of bacteria and copper recovery of this fraction was70 %.