Abstract:Chemical precipitation often occurs during in-situ uranium mining, which affects uranium leaching efficiency. In order to illustrate time and position law of chemical precipitation, spatiotemporal evolution of ore-bearing porosity was numerically simulated under the same conditions of leaching solution. The simulation results show that the 0-5 day simulation zone has porosity-permeability enlargement (chemical dissolution) from 2.6-20 m to injection hole; after the fifth day, the entire simulation zone appears as varying degrees of porosity-permeability reduction (chemical precipitation). When the model was run to the set maximum time (550 days), porosity of model droped by 25.7% in immediate vicinity of injection hole; while porosity of model droped by 15.13% near pumping hole.