铀矿浸出试验柱不同高度上铀金属浸出的规律

Regularities for uranium leaching rate at different heights of column for leaching uranium from uranium ore

针对铀矿堆浸生产中矿堆不同高度上的铀金属浸出存在的延迟现象,采用理论分析和室内柱浸试验研究铀矿浸出试验柱不同高度上铀金属浸出的规律。理论分析将铀矿浸出试验柱沿柱高划分为若干个高度足够小且相等的单元体,使其中单个铀矿石颗粒的浸出符合收缩未反应核扩散控制系统模型,且任意1个单元体内所有铀矿石颗粒反应均匀,不存在延迟现象,进而以1个单元体为目标,根据溶浸剂质量守恒原理,并考虑初始溶浸剂浓度的变化,建立铀矿浸出试验柱不同高度上铀金属浸出的数学模型。采用颗粒半径为2.5 mm的铀矿石进行串联柱浸试验。然后,采用数学模型对柱浸试验结果进行计算,并将模型计算结果与柱浸试验结果进行比较。研究结果表明:试验柱不同高度上铀金属浸出率存在较大差别,且模型计算值与柱浸试验值具有相同的变化趋势,表明该数学模型能较好地反映铀矿浸出试验柱不同高度上铀金属浸出的延迟规律,可为预测铀矿堆浸不同高度上的浸出率提供重要参考。

In order to understand the delay of uranium leaching at different heights in the heap leaching production，theoretical analysis and laboratory column leaching test were used to research the rule of uranium leaching at different heights of uranium leaching test column. The theoretical analysis divided the test column into several small enough and equal columns along the height, which ensures that the leaching of single ore particle corresponds to shrinking core model and diffusion control system, and the reaction of all uranium ore particles is uniform in a small column. Then, one small column was investigated as the typical case to build a mathematical model for the reaction in ideal state, based on the mass conservation principle of leaching agent and consideration the change of initial leaching agent concentration. Laboratory column leaching test of uranium ore was carried out using the uranium ore particles whose size （radius） is 2.5 mm, using a series columns of leaching test apparatus. And the results of the mathematical model of the uranium column leaching were calculated, and the results of model calculation and the results of uranium column leaching test were compared. The results show that the uranium leaching rate at different heights of the column are different, and there are the same trends for the model value and test data. So, the mathematical model is able to respond to the leaching delay at different heights of uranium ore heap, which provides an important reference to predict the leaching rate of uranium at different heights of heap leaching.