新疆某高矿化度地下水分布区砂岩型铀矿采用酸法和碱法地浸时易出现堵塞,采用地球化学模式PHREEQCI模拟和实验研究的方法对堵塞进行了探讨。结果表明,堵塞主要是因为地下水的矿化度(TDS)、Ca2+、Mg2+、SO42-、HCO3-浓度过高,分别为8~12g/L、386.17~775.95 mg/L、250.83~377.21mg/L、2 036.47~2 436.08mg/L、108.66~527.55mg/L,方解石和石膏临近饱和状态;采用酸法和碱法地浸工艺分别会产生石膏和方解石沉淀而引起化学堵塞。该砂岩型铀矿适合采用稀释或水处理—弱碱性地浸工艺。
Blockage tended to occur in high-TDS groundwater area in Xinjiang, China when sandstone-type uranium deposit was acid or alkaline in-situ leached of uranium. The blockage mechanism was discussed based on geochemical simulation PHREEQCI and a series of in-lab experiments. The results show that the main factors to cause blockage are high concentration of TDS, Ca2+, Mg2+, 8042-, and HCO3- in groundwater, which are 8-12 g/L, 386.17~775.95 mg/L, 250.83~377.21 mg/L, 2 036.47~2 436.08 mg/L and 108.66~527.55 rag/L, respectively. Calcite and gypsum are close to saturation state, chemical jamming occurs with the formation of calcite and gypsum deposit respectively produced by acid or alkaline in-situ leaching of uranium. The dilution or treatment-weak alkaline technologies are feasible to treat sand- stone uranium ores.