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根据Al3+与F-能形成稳定的络合离子[AlF6]3-,采用HNO3-Al(NO3)3溶液络合浸出包头混合稀土精矿中的氟碳铈矿。热力学分析结果表明:HNO3-Al(NO3)3体系对稀土精矿浸出反应为自发过程。考察了HNO3浓度、Al(NO3)3浓度、液固比、搅拌速度、温度、搅拌时间这些因素对稀土精矿浸出的影响。实验结果表明:在HNO3浓度3 mol·L-1,Al(NO3)3浓度1.5 mol·L-1,液固比30∶1,搅拌速度300 r·min-1,温度100℃,搅拌时间90 min的条件下,稀土精矿中氟碳铈矿的浸出率达到92.18%,氟碳铈矿与独居石基本分离。通过产物层受界面交换和扩散混合控制的新缩小核模型可用来描述浸出过程的动力学,计算推导出了反应的宏观动力学方程。
According to Al3 + and F-, stable complex ions [AlF6] 3- can be formed, and the bastnaesite in the Baotou mixed rare earth concentrate is complexed with HNO3-Al (NO3) 3 solution. The results of thermodynamic analysis show that the reaction of HNO3-Al (NO3) 3 system with rare earth concentrates is spontaneous. The effects of HNO3 concentration, Al (NO3) 3 concentration, liquid-solid ratio, stirring speed, temperature and stirring time on the leaching of rare earth concentrates were investigated. The experimental results showed that when the concentration of HNO3 was 3 mol·L-1, the concentration of Al (NO3) 3 was 1.5 mol·L-1, the ratio of liquid to solid was 30:1, the stirring speed was 300 r · min-1, the temperature was 100 ℃, the stirring time was 90 min, the leaching rate of bastnaesite in the rare earth concentrate reaches 92.18%, and the bastnaesite and monazite are basically separated. A new reduced core model controlled by interfacial exchange and diffusion mixing of product layers can be used to describe the kinetics of the leaching process, and the macroscopic kinetic equation of the reaction is deduced.