巴彦乌拉铀矿床酸法浸铀的水岩反应堵塞机理

为探讨酸法浸铀过程中含矿含水层的地球化学堵塞机理，运用PHREEQC模拟软件的化学形态和溶解度模拟，分析酸法浸泡试验中浸出液化学反应的化学组成成分，确定含矿含水层化学堵塞矿物的类型，得到含矿含水层发生化学堵塞的原因以及形成条件。根据模拟结果表明：巴彦乌拉地下铀矿中碳酸钙和针铁矿的含量相对较高，当高浓度的溶浸液注入地下含矿含水层之后，溶浸液会溶解碳酸钙和针铁矿，使Ca2+、Fe3+的浓度大幅度上升；当Ca2+、Fe3+浓度反应条件指数大于0时，Ca2+会与SO42-发生反应，生成石膏沉淀，而Fe3+会与阴离子发生反应，生成铁矿物沉淀，导致孔隙率下降，渗透性降低，注液压力增大，注液流量减小，抽液量降低，地浸效益下降。基于以上研究，可为后续实际铀矿床的堵塞和铀的浸出提供参考价值。

Water rock reaction plugging mechanism of acid leaching uranium in Bayanwula uranium deposit

To explore the geochemical blocking mechanism of the ore-bearing aquifer in the acid leaching process, PHREEQC simulation software was used to simulate the chemical morphology and solubility, analyze the chemical composition of leach liquefaction reaction in the acid leaching test, and determine the types of minerals chemically blocked in an ore-bearing aquifer.?The causes and forming conditions of chemical clogging in ore-bearing aquifers are obtained. According to the simulation results: The content of calcium carbonate and goethite are relatively high in Bayanwula underground uranium deposit. When the high concentration of leaching solution is injected into the underground ore-bearing aquifer, the leaching solution will dissolve calcium carbonate and goethite, and the concentration of Ca2+ Fe3+ will increase greatly.?When the reaction condition index of Ca2+ Fe3+ concentration is greater than 0, Ca2+ will react with SO42- to generate gypsum precipitation, while Fe3+ will react with an anion to generate iron mineral precipitation, leading to the decrease of porosity, decrease of permeability, increase of injection pressure, a decrease of injection flow, decrease of extraction volume and decrease of in-situ leaching benefit. Based on the above research, it can provide a reference value for the subsequent plugging of uranium deposits and uranium leaching.