Study of enhanced leaching technology for uranium resources in the decommissioned mining area of an acid in-situ leaching mine

After more than 20 years’ operation of a uranium deposit in Xinjiang, the final mining areas are facing with the problems of low leached uranium concentration, low recovery rate of resource and high operation cost.In order to reduce the decommissioning burden and improve the recovery rate of uranium resources, the study on enhanced leaching test of residual resource is carried out, which taking the goal mining area to be decommissioned as the research object.Firstly, six additional test holes are drilled in the selected target area of the mining area.Through borehole logging, ore composition and mineral analysis, it is found that the remaining uranium resources mostly occurred in mudstone of floor and argillaceous siltstone close to floor.At the same time, reductive minerals and plugging materials of different origin can be found in the ore.Therefore, to improve the recovery rate of the remaining resources in mining area, it is necessary to take measures of enhanced leaching technology.The chemical way of enhanced leaching test which is starting from strengthening coordination reaction and improving oxidation intensity, is carried out.The optimum conditions for the enhanced leaching test are selected.Then, the enhanced leaching test is carried out in the target mining area, and 10.8 t uranium is leached by 6 test units.The results show that although the residual uranium resources in this mining area are in low grade after many years of mining, the residual uranium resources can still be leached by chemical strengthening leaching ways.The research is technically feasible and has the value of popularization and application.