Study On Bioleaching Of JiaMa Low Grade Copper Ore

In our country the copper resources are small reserve and low grade. Recovering copper from low grade ore by bioleaching technology is one of effective way To alleviate the contradiction between supply and demand. In this study, for the JiaMa low grade copper ore,we carride out the bacteria breeding experiment, bacterial growth behavior experiment, shake flask leaching and column leaching experiments, so as to explore the optimum conditions bioleaching of the ore, and provide some references to the utilization of the JiaMa hornfels-type low grade ore.In this study we separated a strain acidophilic bacteria (named XZ) from JiaMa acid mine drainage.Morphological observations showed that the bacteria cell is rod-shaped, 1-2μm long,0.5μm width, The results of condition experiments showed the strain XZ has high oxidation activity in the condition of 30℃ and initial pH=1.5～2.0. During bacterial growth, Fe3+ hydrolyzed and formed jarosite which can easily form at pH-2.4.The result of shake flask leaching experiments showed that leaching speed and leaching rate of bacterial leaching are better than no-bacterial leaching; Under the condition of 10% leaching inoculum size, after 15d the leaching rate reached the maximum, which was 72.15%; When pulp density was lower than 20%, its difference in the concentration had little effect on leaching; Under the condition of initial pH=2-3, the leaching could get optimum effect.The result of column experiments showed the leaching rate of XZ strain was about 32%;the leaching of DB strain was about 36%. Later stage, jarosit might affect the further leaching. Actual leaching result might be greatly affected by complex environmental factors.The result of conbined leaching experiments showed that the change rule of pH, Fe2+, TFe and Orp are closely related; The adsorption mechanism of XZ strain indicated that The smaller particle size is, the higher adsorption rate is; The adsorption rate of 1×107cells/mL inoculating concentration is better than that of 1×108cells/mL; The adsorption of bacteria has obvious selectivity on the surface of chalcopyrite.