The effect of mix ratio and culture type on the bioleaching of a low grade sulfide copper ore using Mesophile bacteria
Subject Areas : Industrial Microbiology
Ali Zarrinpour
1
(
Mining Engineering Faculty, University of Tehran, Tehran
)
Zahra Manafi
2
(
Research & Development division, Sarcheshmeh Copper Complex
)
Mohammad Noaparast
3
(
Mining Engineering Faculty, University of Tehran, Tehran
)
Seyed Ziaaldin Shafaei
4
(
Mining Engineering Faculty, University of Tehran, Tehran
)
Keywords: culture, Bioleaching, mix ratio, Mesophile bacteria,
Abstract :
Background and Objective: In this research, the effect of mix ratio and culture type on the bioleaching of a heap leaching 1 sulfide copper ore using Mesophile bacteria has been investigated. The different bacteria types have a special mechanism in sulfide ore dissolution. So increase recovery can reached with change of bacteria mix ratio. The microorganism, employed in bioleaching process, reach energy for existence from culture and the materials which has been rest under leaching. So the poor and strong culture can be effective for increase of recovery. Materials and Methods: The residual ore of Sarcheshmeh copper heap leaching 1 because of leaching is more than sulfide type. The copper grade at provided sample of heap was 0.23%. About 66% of copper minerals were sulfide which about 51% of them was chalcopyrite. The pyrite amount at the sample was 6%. These tests were down at the shake flask and by using of mixture of mesophile bacteria. Design of experiments was down based on perfect factorial with two levels. Results: Bacteria with producing sulfuric acid at the medium cause more solution and less acid consumption. Norris culture medium in comparison to 9K culture medium causes more recovery for sulfide ore. The reason of this is increase of iron in the solid medium due to precipitation of iron ions and probably formation of Jarosite. The insemination ratio did not show a remarkable effect but amount of added iron ions had a remarkable effect. Conclusion: The maximum of copper recovery was 66.38% after 25 days. The optimum conditions were obtained for reaching to maximum recovery with Norris culture, pH equal 1.6, mix ratio equal 40,40,20 for Tf, Tt, Lf and adding Fe2+ ion (1.5 g/l) .
