摘要
采用地球化学模式计算矿床地下水中硫酸盐、碳酸盐矿物的饱和指数,说明难以采用常规地浸方法开采该矿床的水文地球化学机理。室内和现场地浸试验研究显示,将矿床地下水矿化度淡化至约3.45g/L时,含水层中不会产生硫酸钙、碳酸钙沉淀,使该矿床的地浸开采由不行变为可能。电子探针手段研究表明铀的浸出受铀矿物存在形式的影响,铀矿物与高岭石伴生或产于矿物颗粒之间可以浸出,而产于黄铁矿周边和其它矿物颗粒内部难以或不能被浸出。试验结果表明,随着浸出时间延长,由于矿石和围岩中易溶钙盐的溶解,浸出液中的钙离子浓度会不断增加,将给浸出过程带来堵塞的隐患,因为钙离子的增加,产生碳酸钙沉淀的碳酸氢根离子浓度阈值不断降低,容易产生碳酸钙沉淀而产生堵塞。
The saturation index of sulphate and carbonate in groundwater of Shihongtan uranium deposit in Xinjiang has been calculated by geochemical model PHREEQC. The results indicate that mining of the deposit is a difficult task by traditional acid or alkaline in-situ leaching. Experimental researches of laboratory and field show that mining the uranium deposit is possible because of avoidance of precipitation of calcium sulphate and calcium carbonate in the aquifer, if the total dissolved solids of groundwater were diluted less than 3.45 g/L. The uranium leaching is controlled by species of uranium mineral with study of electron probe. The uranium associated with ka- olin or in between the grains of minerals is easier to be leached out than those associated pyrite or encompassed by the minerals. Experimental researches show that more time of leaching, higher content of Ca2＋ in recovery solu- tion because of ealciemineral dissolution in uranium ora and wall rock. The precipitation jam of calcium carbonate during in-situ leaching will come into being because of reducing the liminal value of HCO3 - content.
出处
《东华理工大学学报（自然科学版）》
CAS
2013年第2期101-106,共6页
Journal of East China University of Technology(Natural Science)
基金
国家自然科学基金(41162007
41172078
40872165)
江西省教育厅(GJJ12375)
放射性地质勘探与技术国防重点学科实验室资助项目(2011RGET05)
关键词
铀矿床
地浸
水岩作用
水文地球化学
uranium deposit
in-situ leaching
water-rock interaction
hydrochemistry
