Abstract:In situ leaching of uranium is achieved by the interaction between the leach solution and uranium minerals. The reaction between the leach solution and various minerals in the ore-bearing layer during the process of uranium extraction by ground leaching will cause a large increase of various ionic components in the leach solution，and when the ionic concentration reaches saturation or supersaturation， chemical precipitation will be produced to cause blockage of the ore-bearing layer. For this reason，it is of great importance to carry out research on the dissolution precipitation characteristics of minerals in ground leaching. In this paper，the dissolution-precipitation characteristics of minerals in the ground leaching process were studied by calculating the mineral saturation index during the operation of the mining area through geochemical simulation based on the chemical composition data Uranium in-situ leaching is achieved by interaction between leaching solution and uranium minerals. The reaction between leaching solution and various minerals in ore-bearing layer during the process of uranium extraction by in-situ leaching will cause greatly increase of various ionic components in leaching solution, and when the ionic concentration reaches saturation or supersaturation, chemical precipitation will be produced to cause blockage of ore-bearing layer. The dissolution-precipitation characteristics of minerals during in-situ leaching were studied by calculating mineral saturation index during operation of mining area through geochemical simulation based on chemical composition data of leaching solution in the C12 mining area of Bayan-Ula uranium mine. The calculation results show that gypsum, Fe(OH)3, goethite, and hematite are easy to precipitate during uranium in-situ leaching. After 6.5 days of in-situ leaching, gypsum is in a state of precipitation. Fe(OH)3, goethite and hematite are in the precipitation state when pH value is greater than 6.71—6.89, 4.6—5.0 and 4.62—4.87, respectively. The key factor affecting dissolution and precipitation of minerals is pH value.