为了研究堆浸铀矿石粒径分布对堆浸效果的影响,配置5组不同粒径分布分维数的铀矿样进行室内柱浸试验,测定不同时刻浸出液的铀浓度和pH值,计算对应时刻的浸出率和酸耗。结果表明:分维数越大的铀矿样,浸出液中铀离子浓度峰值出现得越迟、峰值越小,且在峰值出现后,铀离子浓度越大;在浸出初期,分维数越大的铀矿样,浸出率越低,这种差距在浓度峰值出现之前逐渐增大,峰值过后逐渐减小;而在浸出后期,分维数大的铀矿样的浸出率依次逐渐超过分维数较小的铀矿样的浸出率,并保持进一步扩大的趋势;在浸出初期,若要获得相同的浸出率,分维数越大的铀矿样,其酸耗量也越大,酸耗量的差距随着浸出时间的延长先增大而后逐渐减小;在浸出后期,要获得相同的浸出率,酸耗则出现相反的变化情况。
Uranium ore heap for heap leaching is a kind of loose media which is heaped by broken uranium ore with different sizes. In order to study the influence of the uranium ore particle size distribution on the heap leaching, five groups of uranium ore samples with different fractal dimensions of particle size distribution were prepared for indoor column leaching tests. The uranium concentration and pH of the pregnant solution at different times were determined, and the corresponding uranium recovery and the acid consumption were calculated. The results show that the larger the fractal dimension of the particle size distribution is, the later the uranium ion concentration peak will appear and the lower the peak value will be. Before the peak valfle appear, the uranium ion concentration in the pregnant solution of uranium ore samples with larger fractal dimensions of particle size distribution is lower than that in the with smaller fractal dimensions. And after the peak, the situation is just the opposite. In the early phase of leaching, the larger the fractal dimension is, the lower the uranium recovery will be. As the leaching reaction proceeds, this difference increases at first, and then decreases gradually. In the late phase of leaching, the leaching rate of ore samples with larger fractal dimensions exceeds that of ore samples with smaller fractal dimensions, and the trend will be maintained. In the early phase of leaching, if the same uranium recovery is to be obtained from all samples, the uranium ore sample with larger fractal dimension will consume more acid. The difference between acid assumptions increases at first, and then decreases gradually. In the late phase of leaching, the situation is just the opposite.