Abstract:Uranium extraction by ground leaching is the main mining method for sandstone-type uranium mines, and not only is uranium dissolved after the acidic leach solution reacts with the ore, but a large number of impurity ions are also transferred into the leach solution. This paper takes a pumping unit in the northern part of C12 mining area of Bayan Wula uranium mine as the research object, and carries out a systematic research on the evolution characteristics of the chemical composition of leach solution by monitoring the chemical composition of leach solution from its pumping holes. The results show that the increase in ion concentration of leach solution is the result of the interaction between the high acid leach solution and the minerals in the ore-bearing layer, and the evolution of ion concentration goes through three stages, namely, rising, rapidly rising and relatively stable, and the higher the acidity, the faster the rate of increase in concentration, and the order of the reaction between minerals and sulphuric acid is roughly as follows: carbonate, pyrite (iron oxides), silica-alumina, sodium feldspar, and potassium feldspar; the growth rate of the concentration of the cations concerned is similar to the growth rate of SO42- concentration. SO42- concentration growth rate evolution characteristics have synchronization, SO42- concentration more than 12g / L Ca2+ concentration appeared to decrease, indicating that the precipitation of CaSO4 occurred. These research results have important theoretical significance and high academic value for indicating the evolution of mineral dissolution and migration.