Hydrodynamic Simulation of the Influence of Injection Flowrate Regulation on In-Situ Leaching Range

Reasonable control of the leaching range is one of the critical indicators of the in-situ leaching uranium mining process. However, there is currently no mature control technology. To verify and improve the current control technology of the leaching range in the industry, this work proposes an injection control mode for a small flow around the well-site and establishes a hydrodynamic model of the leaching range under eight different pumping and injection conditions by using the groundwater modeling system (GMS). The model calculation, range prediction, comparative analysis, and on-site SO42- and S isotope verification tests were carried out. Results show that with the change of liquid injection ratio, the area ratios of fixed pumping injection ratio (total pumping flowrate is greater than 0.3% of the total injection flowrate) and model leaching range under four pumping injection equilibrium conditions were 99.10%, 99.99%, 98.30%, and 97.95%, respectively. The farthest migration distance ratios of the leaching solution were 99.37%, 100%, 98.02%, and 97.58%, respectively. It is considered that the operation mode with a fixed pumping injection ratio has no noticeable control effect on the leaching range; selecting a reasonable proportion to regulate the flowrate of injection wells at different positions can effectively reduce the area of the groundwater flow field and realize the effective control of the leaching range. The research results are conducive to saving a lot of evaporation pool construction, land acquisition, human and material resource investment, and environmental policy pressure.