Testing the ability of a low grade sphalerite concentrate to achieve autothermality during biooxidation heap leaching

The operation of the large diameter column was successful in demonstrating that the GEOCOAT® process can be operated autothermally at mesophilic temperatures treating a low-grade sphalerite concentrate. Zinc dissolution in excess of 90% can be achieved in a leach time of 60 days, while results of small diameter column testing indicate zinc dissolutions in excess of 95% in 60-100 days.