(中国地质大学材料科学与工程学院,北京100083)
摘 要: 以四川某地锂云母矿石经选矿预处理所得锂云母精矿为原料,研究在硫酸介质中锂云母的分解反应过程。结果表明:在硫酸浓度为4.2 mol/L、硫酸与锂云母液固质量比为3:1、温度为433 K、转速为30 r/min条件下反应4 h,Li2O的溶出率达96%。反应动力学实验结果表明:锂云母酸解反应属于固膜扩散控制,分解过程符合液-固单颗粒反应模型中的缩芯模型;反应的表观活化能为Ea为28.3 kJ/mol,阿伦尼乌斯常数k0为2.608,反应级数n为0.998。
关键字: 锂云母;分解反应;动力学;硫酸介质
(School of Materials Science and Technology, China University of Geosciences, Beijing 100083, China)
Abstract:The decomposition of lepidollite in sulfuric acid solution was studied and the lepidolite concentrate from Sichuan province was obtained by mineral separation pretreatment and its kinetics were studied. The results reveal that the dissolution rate of Li2O in the lepidolite sample reaches 96% when it was hydrothermal-treated at 433 K for 4 h, with the sulfuric acid concentration of 4.2 mol/L, the sulfuric acid lepidolite liquid to solid mass ratio of 3:1, and the stirring speed of 30 r/min, respectively. The kinetics research results indicate that the reaction of the lepidolite decomposition in sulfuric acid solution is controlled by solid membrane diffusion, and the decomposition conforms to the shrinking core model of the liquid-solid single particle reaction model, with the apparent activation energy (Ea) of 28.3 kJ/mol, the Arrhenius constant k0 of 2.608, and the reaction series n of 0.998.
Key words: lepidolite; decomposition reaction; kinetics; sulfuric acid solution