CO2预疏通含碳酸盐超埋深砂岩铀矿层探讨

Study on Pre-dredging Carbonate Contained Deep Buried Sandstone Uranium Deposit by CO2

某地浸采铀试验矿床埋深超过700 m,渗透系数为0.47~0.56 m/d。为提高矿层渗透性,对目标矿层进行了CO2预疏通试验。实验室研究表明,CO2预疏通提高了HCO-3浓度,使流出液流速提高60%,金属离子弱溶出,同时降低了铀随预疏通溶液的溶出率。现场试验表明,矿层注液量提高32%,注液压力降低28%,显示预疏通对矿层渗透性提高效果明显。通过分析和计算,深部矿层本身的压力可提高CO2溶解度,进而提高水溶液解离产生的离子浓度,有利于增强疏通效果。

An ISL deposit is buried more than 700 m depth.Its permeability in drawing test is between 0.47~0.56 m/d.In order to improve the permeability of the ore,pre-dredging the target ore bed test was carried out by CO2.Laboratory investigation indicates that concentration of HCO-3 is increased 60%in the effluent,metal ions are weakly leached out,and the leaching rate of uranium in the pre-dredging effluent is decreased.Field test indicates that volume of injecting liquid is increased 32%,and pressure of injecting liquid is decreased 28%.The test results show that the permeability of the ore bed is greatly increased by the pre-dredging experiment with CO2.Through analysis and calculation,the own pressure of the deep buried ore body can increase the solubility of the CO2,which in return can increase ion concentration in the water by ionization process.It has benefit effect to pre-dredging process.