Sulfide Copper Concentrate Pressure Oxidation Acid Leaching Pilot Study

The pyrometallurgy process is mature for copper sulfide concentrate at present, but the pyrometallurgy process have many disadvantages, For example, in order to reduce the cost of this process, we must to build a bigger plant; It will bring on severity dust pollution; besides , the low grade tailings and goaf can not be dealt with by the pyrometallurgy process. Compared with the pyrometallurgy process, the hydrometallurgy process have more advantages, for instance, the planning scale can big or small;the low gread ore can be managed, it is a friendly condition process without dust and sulfur dioxide flue gas pollutions; what's more, it is a simple working procedure , low energy consumption and low cost process. Based on the several reasons above, a new process of pressure and oxidizing leaching aim at copper sulfide concentrate is investigated in this thesis.Through experimentation, a good many of complications about use sulfuric acid and hydrochloric acid to leach copper sulfide concentrate have been analyed and investigated. The best of process conditions about sulfuric acid and hydrochloric acid have been found. When we use sulfuric acid to leach the copper sulfide concentrate, if the leaching temperature between 112.6℃ and 165℃, the sulfur wrap will come into being, so the copper recovery would be reduce. Taking into account the whole process, in order to reclaim the sulfur as byproduct, we have to do the pressure and oxidizing leaching experiment with sulfuric acid in the temperature above.So a series of single factor experiment about how to enhance the copper leaching rate have been done, which include leaching temperature, agitation intensity, sulfuric acid dosage, oxygen pressure, sodium lignosulphonate dosage, L/S ratio, leaching time and grinding time. Under the best of conditions, the leaching rate of copper is 82. 18%, the grade of copper leaching residues is 6.03%. The result is bad, so we. should explore the feasibilityof hydrochloric acid leaching.Hydrochloric acid is a strongly caustic acid, so if we use it to leaching, the temperature conditions must be lower. Therefore we can not reclaim the sulfur as byproduct. Under 112. 6℃, a series of single factor experiment about how to enhance the copper leaching rate have been done, which include hydrochloric acid dosage, leaching time, oxygen pressure, leaching temperature and L/S ratio. Under the best conditions, the leaching rate of copper is 96.84%, the grade of copper leaching residues is 1.21%. The result is better than pyrometallurgy process.The result of these experimentation about sulfuric acid leaching and hydrochloric acid leaching has been integrated analyzed in this thesis, we have found some useful conclusion. Compared with the leaching conditions and the leaching result, we have found that use the hydrochloric acid to leach the copper sulfide concentrate in the pressure and oxidizing conditions is better than sulfuric acid, what's more, the cost of this process has been estimated, the conclusion is that use the hydrochloric acid to leach the copper sulfide concentrate in the pressure and oxidizing conditions is feasible. So this thesis commend that the process use the hydrochloric acid.