地浸采铀过程中含矿层堵塞特征研究

Study on Characteristics of Ore-Containing Layer Blockage during In-situ Leaching of Uranium Mining

酸法与碱法浸铀是当前我国铀矿采冶主要地浸工艺,浸铀过程中均会产生含矿层堵塞。含矿层堵塞是地浸采铀中的一种普遍现象,也是制约铀浸出效益的重大瓶颈。根据巴彦乌拉铀矿矿石酸法柱浸试验和十红滩铀矿矿石碱法浸铀试验结果,分别对酸法和碱法浸铀过程中含矿层堵塞的原因进行了系统研究。结果表明,矿物黏土化蚀变是造成酸法地浸中含矿层堵塞的重要原因;碳酸钙沉淀是造成碱性地浸中含矿层堵塞的主要原因;溶浸液的pH、HCO^(-)_(3)浓度及Ca^(2+)浓度过高都会引起碱性浸铀含矿层碳酸钙沉淀,碳酸钙溶解沉淀特征受pH、Ca^(2+)、HCO^(-)_(3)的边界值控制。

Acid leaching and alkali leaching of uranium are the most important in-situ leaching processes for uranium mining and smelting in China and ore-bearing layer will be blocked during uranium leaching.Ore-bearing layer blockage is a common phenomenon in in-situ leaching of uranium,and it is also a major bottleneck restricting the efficiency of uranium leaching.According to the results of acid column immersion test of Bayan Ula uranium ore and alkaline column immersion test of Shihongtan uranium ore,the causes of ore-bearing layer blockage during acid and alkali uranium leaching were systematically studied.The results show that mineral clay alteration is an important cause of blockage of ore-bearing layer in acidic in-situ leaching,while calcium carbonate precipitation is the main reason for blockage of ore-bearing layer in alkaline in-situ leaching.The pH value,HCO^(-)_(3)concentration and Ca^(2+)concentration of leaching solution would cause calcium carbonate precipitation in alkaline in-situ leaching of uranium-bearing layer.The solubilization profile of calcium carbonate is controlled by the boundary values of pH value,concentration of Ca^(2+)and HCO^(-)_(3).