Abstract:Hematite, as common uranium associated mineral, will generate ferric iron ions during in-situ leaching of uranium. In order to investigate changes produced by hematite water-rock interaction and effect on uranium leaching during uranium leaching by acid method, different models were built and contrastively analyzed in presence of hematite applying Bayan Wula uranium in-situ leaching as example. The results show that: 1) at the end of simulation (500 d), dissolution rate of hematite is relatively slow, only 12.86% of hematite in ore layer at injection hole 1 and injection hole 2 dissolves, and the dissolved area also shows a trend of polarization due to influence of artificial flow field formed by pumping. In addition, hydraulic fields between two adjacent liquid injection holes also interact with each other. In solution region of injection hole 1, distance from injection hole is 14.1 m at the farthest point, and distance from injection hole is 8 m at the nearest point. In solution region of injection hole 2, distance from injection hole is 12 m at the farthest point, and distance from injection hole is 7 m at the nearest point. 2) Existence of hematite in ore layer has big impact on uranium leaching, dissolution of uranium deposits was accelerated by ferric iron ions produced by hematite dissolution. When only 1.08% hematite is contained in ore layer, pitchblende in area of injection hole 1 of production model only needs 11 days to be completely dissolved, while pitchblende in the same area of the ideal model needs 75 days to be completely dissolved. At the end of whole simulation process (500 days), in production model, the furthest distance of completely dissolved uranium ore is only 12.2 m from pumping hole, while in ideal model, the completely dissolved uranium ore area is 24.4 m from pumping hole. 3) Hydraulic fields formed by pumping have a very important effect on the whole in-situ leaching of uranium. Both path and time of leaching solution migration and tendency and trend of ore layer dissolution are affected by artificial flow field. Therefore, it is necessary to reasonably arrange pumping system, in the actual production, there is no dead angle of hydraulic field in mining area, and all areas can be covered by leaching solution.