Environmental Assessment Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400 085, India.
J Environ Manage. 2011 Mar;92(3):919-25. doi: 10.1016/j.jenvman.2010.10.046. Epub 2010 Nov 16.
A semi-dynamic leaching test was carried out for metallurgical wastes and ore samples from the uranium and copper mining industry over a 142 day period using distilled water and 0.1N NaNO(3) as solvents. Laser fluorimetry was used as the analytical technique to determine the total uranium content in the leachates. The cumulative leach fraction (CLF) of uranium release from the samples was calculated to be 0.22, 0.22, 0.07 and 0.39% for rock, uranium tailings, copper kinker ash samples and copper tailings respectively using distilled water as solvent and 0.31, 0.27, 0.05 and 0.59% for the same matrices using 0.1N NaNO(3). The release of mobile uranium fraction was very slow, being faster in the initial stage and then attained a near steady state condition. The diffusion coefficient and bulk release of uranium from the samples have been calculated. The processes governing the release of uranium from these matrices have been identified to be surface wash-off and diffusion. Hence the use of weak solvents (leach out the mobile/exchangeable fraction of uranium) under semi-dynamic conditions aids the determination of leaching parameters and identification of the leaching mechanism for mobile uranium fraction from different matrices by slow leaching processes.
采用半动态浸出试验，选用蒸馏水和 0.1N NaNO3 作为溶剂，对铀矿和铜矿采冶废物和矿石样品进行了为期 142 天的浸出实验。采用激光荧光法作为分析技术，测定浸出液中铀的总含量。结果表明，用蒸馏水作为溶剂时，岩石、铀尾矿、铜转炉灰渣和铜尾矿的铀累积浸出分数（CLF）分别为 0.22%、0.22%、0.07%和 0.39%；而用 0.1N NaNO3 作为溶剂时，CLF 分别为 0.31%、0.27%、0.05%和 0.59%。可动态铀释放速度非常缓慢，初始阶段较快，然后达到近稳态。计算了样品中铀的扩散系数和整体释放量。确定了控制这些基质中铀释放的过程为表面冲洗和扩散。因此，在半动态条件下使用弱溶剂（浸出铀的可动态/可交换态部分）有助于通过慢速浸出过程确定不同基质中可动态铀部分的浸出参数和浸出机制。
