硅酸盐-磷酸盐对酸法地浸采铀退役采区模拟地下水的修复

为探索酸法地浸采铀退役采区地下水的原位修复技术，本研究先从西北某酸法地浸采铀退役采区采取地下岩心样，同时制备了酸法地浸采铀退役采区地下水模拟水样，构建模拟修复反应的微模型；再向微模型中分别加入硅酸钠溶液、磷酸二氢钾溶液、硅酸钠-磷酸二氢钾混合溶液以考察其对地下水的修复效果。结果表明：加入的硅酸钠-磷酸二氢钾与铀反应形成了胶磷钙铁矿(Ca₆Fe₉(PO₄)₉O₆(H₂O)₆.3H₂O)、偏钠铀矿物(Na(UO₂)(PO₄).3H₂O)和(NaPUO₆.3H₂O)三种矿物；沉淀物中铁锰氧化物交换态铀的含量增加到了41%；铀的去除率达到了99.72%。

Remediation effect of silicate-phosphate on simulated groundwater in the decommissioned mining area of acid in situ leach uranium mining

In order to explore the in-situ remediation technique for groundwater in the decommissioned mining area of acid in situ leaching uranium, silicate and phosphate, which are green remediation agents with low cost and no secondary pollution, was used to repair it. The sandstone uranium ore samples were firstly taken from a decommissioned area of acid in situ leach uranium mining in northwest China, the simulated water samples were prepared based on the groundwater in the decommissioned field, and the microcosm for simulating the remediation reaction in the groundwater was constructed. Then, sodium silicate solution, potassium dihydrogen phosphate solution and the mixed solution including both of them were added into the microcosms, respectively, and their remediation effects on groundwater were monitored. The results show that sodium silicate-potassium dihydrogen phosphate could react with uranium, and three minerals of mitridatite [Ca6Fe9(PO4)9O6(H2O)6.3H2O], metanatroautunite (Na(UO2)(PO4).3H2O) and (NaPUO6.3H2O) occurred. The content of Fe-Mn oxides-bound uranium increased to 41%, and the removal rate of uranium reached 99.72%.