The effect of solid weight percent and pH in recovery of copper from low- grade sulphidic ores by bioleaching

In order to study the activity of Thiobacillus ferrooxidans bacterium on bioleaching process and also to evaluate the optimum copper recovery from sulphidic ores, various w/v percents of this ore containing 0.62 percent copper were applicated on basal medium of this bacterium. Every four days, the amount of copper, ferric ion and pH of the solutions were measured. The results of measuring showed that the pH on total solutions was decreased. Amounts of released copper by bacteria were increased on the total of treatments versus the time. The highest released copper was observed on 50 and 60 percent w/v sulphidic ores which was 93.1 and 94.7 percent respectively. The amount of ferric ion increased on 1- 10 w/v percent sulphidic ores versus the time. The highest ferric ion was observed on 20 percent w/v sulphidic ores. The concentration of ferric ion was increased on 20 – 70 w/v percents during the first 20 days and then was decreased. The color of culture media changed more than 20 w/v percent sulphidic ores. The results of this study are effective on bioleaching practical plan in order to optimize copper recovery from sulphidic ores.