表面活性剂提高铀矿石浸出率研究

Surfactant Study on Promoting Leaching Rate of Uranium

为了解决铀矿堆浸过程中渗透性差以及浸出率不高的问题,通过添加表面活性剂提高渗透性而强化铀矿石浸出。本研究采用静态实验研究3种不同的表面活性剂脂肪酸甲酯磺酸盐(MES)、十二烷基硫酸钠(SDS)、吐温80对铀浸出率的影响,并测定溶浸剂的表面张力,选出使铀浸出率提升最大的表面活性剂后确定其最佳用量;再通过动态柱实验进一步研究铀矿堆浸过程中表面活性剂对渗透性大小的改变及铀浸出率的影响。静态实验结果表明:3种表面活性剂均能提高铀浸出率,其中十二烷基硫酸钠对铀的浸出效果最好且使溶浸剂表面张力降低最低,为52.94%;接近临界胶束浓度时铀浸出率最高,故选用0.008 mol·L-1的十二烷基硫酸钠进行动态实验。动态实验结果表明:十二烷基硫酸钠的加入最终使实验柱的渗透系数提高至4.6倍,铀的浸出率由48.41%提升至60.20%,增加了11.79%。表面活性剂增大了铀矿石堆浸过程中的渗透性,使铀浸出率提高。

Surfactant was added into the leachant to improve the permeability and leaching rate of uranium in the process of uranium ore heap leaching. A series of static experiments were conducted to study the effects of three different surfactants： fatty acid methyl ester sulfonate（ MES）,sodium dodecyl sulfate（ SDS）,Tween-80 on the leaching rate of uranium and test the surface tension of leachant; then the surfactant with the maximum uranium leaching rate was chosen out and its suitable dosage was determined. Last,the influences of surfactant on permeability and leaching rate of uranium were studied by column experiment. The static experiment results showed that the three surfactants could strengthen uranium ore leaching,SDS had the best effect among them and the surface tension of leachant was decreased to 52. 94%. When close to the micellar concentration,the highest leaching rate of uranium was achieved. So the SDS concentration of 0. 008 mol·L- 1was selected to conduct the column experiments. In the column experiments,the addition of SDS made the permeability coefficient increase to 4. 6 times finally. Meanwhile,the leaching rate of uranium rose from 48. 41% to60. 20%,which increased by 11. 79%. Surfactant increased the permeability in the uranium ore heap leaching and improved the leaching rate of uranium.