APPLICATION OF BIOLEACHING OF COPPER FLOTATION TAILINGS

The lack of new deposits with a rich copper content and the depletion of old deposits, as well as the need to comply with environmental requirements, raises the issue of the need to process the tailings of metallurgical industries. In Kazakhstan was accumulated significant stocks of tailings "Borgezsay" and "Staroye". The tailings reserves are estimated at up to 1 billion tons. Sample evaluation showed that the average copper content in the tailings is 0.15-0.2%. More than 1 million tons of copper are stored in this tailings. The complexity of the structure of minerals passes through the process of leaching of these wastes. Several types of leaching in sulfuric acid were considered for processing. Methods using chalcopyrite as a catalyst or dissolution with chlorides were not economically efficient. Studies have been carried out on the use of copper bioleaching. Bioorganisms destroy various minerals of metals, ensures the transition of metals into the leaching solution. Thionic bacteria Acidithiobacillus ferrooxidans were used. The strains of these iron-oxidizing bacteria occupy an exceptional position among thionic bacteria, since in addition to the ability to autotrophic growth due to the oxidation of sulfur compounds, they can use the energy of oxidation of ferrous iron. Studies have shown that the use of these bacteria can reduce the copper content in samples from 0.2% till 0.05%, in some cases down to 0.005%. Bioleaching carried out on various tailings samples showed the effectiveness of this method.