Effect on iron dispose and copper extraction from inoculation of native bacterial consortiums on column leaching test

摘要

This study assessed the contribution in the extraction of copper by the native iron oxidizing microorganism consortiums present in the water from mine upwelling found in a copper deposit belonging to a mining company located in the North of Chile. A set of bioleaching columns was generated, each loaded with low grade copper sulphide (total copper 0.68 and soluble copper 0.19) and submitted to different treatments, consisting in the addition of a determined amount of mine upwelling water with native iron oxidizing microorganism consortiums to the wash solution for the columns (raffinate).The results from tests show increases of between 4% and 7% over the normal copper extraction levels. Kinetic analysis of the bioleaching activity (Qs) for the pregnant leach solution (PLS) showed considerable microbial activity. Statistical analysis back the increase of copper in the columns treated with bioleaching activity.These results are promising, and show considerable potential for a future study and the industrial use of this bioleaching method in heaps of low grade copper sulphide, which could lead to previously unforeseen extraction levels.