Effects of Copper Extraction Process on Acidithiobacillus ferrooxidans

In the process of bioleaching-solvent extraction-electrowinning for copper,the bioleaching process will be inevitably affected by the extraction operation.The effects of copper extraction process on Acidithiobacillus ferrooxidans were studied by utilizing the most probable number(MPN)method under the condition of different main parameters of extraction.The results showed that when aqueous feed was at pH 1.5—3.0,the bacterial cell concentration increased in the raffinate,meanwhile,the proportion of active bacteria in the raffinate accounted for a largest percentage of 24.8% at pH 2.0.While Lix984 N volume concentration was in the range of 2.5%—15%,the bacterial cell concentration decreased in the raffinate,the proportion of active bacteria in raffinate decreased from 23.6% to 6.2%.It was revealed that the extraction process exerted interceptive influence on the leaching bacteria,which would lead to the decrease in the concentration of bacteria cell back to heap leaching environment.Meanwhile,the bacterial activity would be weakened by the extraction process,which would decline the bioleaching efficiency accordingly.