铀矿堆浸酸性尾渣中和的动力学特征及模型

采用氧化钙、氢氧化钠和氨水作为中和剂,对铀矿堆浸酸性尾渣进行中和试验,试验过程中检测了中和体系的pH随时间的变化,并根据检测结果建立了尾渣中和的动力学模型。结果表明,铀矿堆浸酸性尾渣的中和过程,包括尾渣颗粒表面余酸与中和剂的快速反应,及尾渣颗粒内部余酸与中和剂的缓慢扩散-反应两个阶段;中和过程中,中和剂扩散-反应的非线性耦合和反馈作用模型,可很好地反映尾渣中和反应的过程和方式,中和体系的pH呈现出明显的非线性振荡现象;尾渣中和的动力学模型,能很好地拟和中和体系的pH随时间的变化。

Dynamic Characteristics and Model for Centralization Reaction of Acidic Tailings From Heap Leaching of Uranium Ore

Centralization tests were carried out on acidic tailings from heap leaching of uranium ore by using CaO, NaOH and NH₄OH. The variations of pH with time were measured for the three centralization systems and the dynamic models for the systems were set up by regressing the measured data. The centralization process consists of the fast reaction phase representing the reaction between the centralization agent and the acid on the surface of the tailing’s particles and the slow diffusion-reaction phase representing the diffusion-reaction between the centralization agent and the acid within the tailing’s particles. The non-linear coupling and feedback function model for the diffusion-reaction of the centralization agent can reflect the process and mode of the centralization reaction. There is a non-linear oscillation in the variation of pH within the centralization systems. The dynamic model for the tailing’s centralization reaction can fit the pH variation within the centralization systems.