[en] Qianerkuai uranium deposit contains high carbonates and rich clay. It is a low penetrability sandstone uranium ore which can be exploited by in-situ leaching technique. During the pilot production, the blinding phenomena occurred because of its low penetrability. According to the in-situ uranium leaching mechanism, the 001 x 7 cation exchange resin was selected to remove Ca²⁺ and Mg²⁺ from the injection liquid, which are the main cations to form the precipitation. The experiment results show that the removal effect of Ca²⁺ and Mg²⁺ is excellent. This technique can be applied in in-situ leaching of uranium. (authors)