【摘要】 基于单因素条件实验结果,对α型锂辉石在混酸介质HF/H₂SO₄中不同温度下的浸出动力学进行系统研究。结果表明:在矿物/HF/H₂SO₂比1 g:3 mL:2 mL、50～100°C条件下,锂的浸出过程符合缩核动力学模型,浸出速率主要由表面化学反应以及产物固膜扩散共同控制,表观活化能Ea为32.68 kJ/mol。对固相不溶渣及浸出液组成的分析结果显示:固膜的形成主要由浸出过程中不溶氟化物,如锂钠冰晶石(Na₃Li₂Al₂F₁₂)、钠冰晶石（Na₃AlF₆）、氟化钙（CaF₂）、钾冰晶石（K-2AlF₅）、氟化铝（AlF₃）及少量氟硅酸盐（Na_SiF₆、KNaSiF₆）的生成所致。此外,氢氟酸添加量及浸出温度可通过影响HF分子在浸出锂、铝和硅间的分配而影响浸出过程的选择性。更多还原

【Abstract】 An enhanced leaching of Li from α-spodumene was carried out using a mixture of hydrofluoric and sulfuric acid（HF/H₂SO₄） as the medium. Based on the optimized leaching conditions, the leaching kinetics of Li was investigated in an ore/HF/H₂SO₄ ratio of 1:3:2 g:mL:mL with leaching temperature ranging from 50 to 100 °C. The results indicate that the leaching kinetics of Li fitted well with a model based on the shrinking core model. In addition, the leaching rate of Li was controlled by chemical reactions and diffusion through the product layers. The apparent activation energy Ea was calculated to be 32.68 k J/mol.Solid films were formed because of the generation of insoluble products such as cryolithionite(Na₃Li₂Al₂F₁₂), cryolite（Na₃AlF₆）,calcium fluoride（CaF₂）, potassium cryolite（K₂AlF₅）, aluminum fluoride（AlF₃）, and fluorosilicates（Na₂SiF₆ or KNa SiF₆）.Furthermore, the effects of the ore/HF ratio and leaching temperature on the leaching behavior of Li, Al and Si were investigated.The results indicate that the ore/HF ratio and leaching temperature could clearly affect the distribution of HF molecules on the leaching of Li, Al and Si, which are important for the selective leaching of Li over Al and Si with this fluorine-based chemical method.更多还原