基于管状浸出实验的地浸开采井间距研究

为探讨地浸开采井间距的合理性,选取新疆某矿床Ⅰ-Ⅱ旋回铀矿石样品开展酸法管状浸出实验,分管体饱水和无试剂浸出、质量浓度为5g/L的硫酸稀酸浸出两个阶段进行。实验装置由注液端向出液端按一定间距依次布置5个监测断面,按8h间隔取样,重点分析浸出液的铀浓度、pH值、三价铁离子和总铁浓度等参数,探究不同监测断面参数变化特征及其与浸出剂运移距离的关系。结果表明,地浸采铀过程是一个浸出铀逐渐累积的过程,且其累积速率受井间距控制;铀浓度峰值的大小与浸出剂浓度、铀矿石品位正相关,铀浓度峰值出现的快慢与渗透速度的大小成正比;根据拟合公式,铀浓度峰值并不随着溶浸路径的增加而线性增加,而与浸出剂运移距离呈近似对数关系,随溶浸路径的延长而升高,但增速逐渐减缓,在40m的溶浸过程中,铀浓度累积量的95%在前27m内完成,因此,确定该地段矿体的酸法地浸开采合理井间距为27m左右。

Study on Well Spacing in In-situ Leaching Mining Based on the Tubular Leaching Experiment

In order to investigate the reasonable well spacing for in-situ leaching, the acid tubular leaching experiment is carried out on uranium ore samples from I - II cycles of a deposit in Xinjiang. The experiment was divided into two stages: saturated water leaching, reagent free leaching and dilute acid leaching with 5 g/L sulfuric acid. In the experiment, five monitoring sections are arranged from the injection end to the outlet end at a certain interval, and samples are taken at 8 h intervals. The parameters of uranium concentration, pH value, ferric ion and total iron concentration of the samples are analyzed to explore the variation characteristics of parameters in different monitoring sections and their relationship with the leaching agent migration distance. The results show that: the process of in-situ leaching is a gradual accumulation of uranium, and the accumulation rate is controlled by well spacing; the peak value of uranium concentration is positively related to the concentration of leaching agent and the grade of uranium ore; the speed of the peak value of uranium concentration is directly proportional to the infiltration rate; according to the fitting formula, the peak uranium concentration does not increase linearly with the increase of leaching path, but has a logarithmic relationship with the migration distance of leaching agent. It increases with the extension of leaching path, but the growth rate gradually slows down. In the 40 m leaching process, 95% of the accumulation of uranium concentration is completed in the first 27 m. Therefore, the reasonable well spacing of acid in-situ leaching mining is about 27m.