真空碳热还原锂辉石矿提取Li同时回收Si和Al的探究  

Vacuum Carbothermal Reduction of Spodumene Ore to Extract Li and Simultaneous Recovery of Si and Al

作　　者：吕飞 杜昊[1,3,4] 曲涛 施磊[1,3,4] 田源 戴永年 Lv Fei;Du Hao;Qu Tao;Shi Lei;Tian Yuan;Dai Yongnian(State Key Laboratory of Clean Utilization of Complex Non-Ferrous Metal Resources,Kunming University of Science and Technology,Kunming 650093,China;National Engineering Laboratory for Vacuum Metallurgy,Kunm ing University of Science and Technology,Kunming 650093,China;Key Laboratory of Vacuum Metallurgy for Nonferrous Metal of Yunnan Province,Kunming 650093,China;Faculty of Metallurgical and Energy Engineering,Kunming University of Science and Technology,Kunming 650093,China)

机构地区：[1]昆明理工大学真空冶金国家工程实验室,云南昆明650093 [2]昆明理工大学省部共建复杂有色金属资源清洁利用国家重点实验室,云南昆明650093 [3]云南省有色金属真空冶金重点实验室,云南昆明650093 [4]昆明理工大学冶金与能源工程学院,云南昆明650093

出　　处：《稀有金属》2023年第4期547-554,共8页Chinese Journal of Rare Metals

基　　金：国家自然科学基金项目(51604133);云南省院士自由探索基金项目(202005AA160008)资助。

摘　　要：针对目前锂辉石矿提锂工艺资源利用率低、对环境污染大等问题,探究一种全新的处理锂辉石矿的方法:从锂辉石矿中提取Li的同时对其中占主要成分的Si和Al进行回收。通过理论计算和实验探究表明,直接碳热还原锂辉石提取Li同时制备Al-Si合金的工艺很难实现,矿石中的SiO_(2)被还原SiC和SiO气体,无法得到单质Si,而Li Al Si_(2)O_(6)由于自身非常稳定,在实验温度范围内不会发生反应。加入Fe2O_(3)碳热还原锂辉石矿提取Li同时制备Si-Fe合金回收Al_(2)O_(3)的理论和实验探究表明,Fe2O_(3)可以有效促进锂辉石中SiO_(2)和Li Al Si_(2)O_(6)碳热还原反应的发生。还原过程中Li被还原为Li蒸气在冷凝系统中得到收集,同时在还原剩余物中可以得到Si-Fe合金和Al_(2)O_(3)。因此,本文提出添加Fe2O_(3)真空碳热还原锂辉石矿提取Li同时制备Si-Fe合金回收Al_(2)O_(3)的工艺,整个还原过程中,Li的还原率为92.69%,冷凝物中的Li2O含量为36.21%,同时在还原剩余中可以将矿石中的Al和Si以Al_(2)O_(3)和Si-Fe合金的形式有效分离。与现有的锂辉石矿提锂技术相比,本方法具有工艺流程简单,几乎不产生废水、废渣,对环境友好、资源利用率高等优点。In recent years,lithium consumption has increased significantly owing to its extensive use in portable electronic devices,power devices such as electric vehicles,and grid energy storage.Spodumene ore is the most widely used raw material in lithium extrac⁃tion technology from ores.The existing processes for extracting Li from spodumene ore are all based on the principle of high-tempera⁃ture roasting to excite the minerals chemically.The processed spodumene ore is subsequently acid or alkali leached to extract Li from the spodumene crystal lattice.Using sulfuric acid for the above process is currently the most tested approach for extracting Li from spodumene ore.However,the existing lithium extraction technology from spodumene ore involves the conversion of the main compo⁃nents(16%~25%Al_(2)O_(3) and 50%~75%SiO_(2))in the spodumene ore while producing an acid/alkaline Al-Si-based hazardous waste.This represents a significant waste of resources,because residues from the spodumene process are difficult to handle and can cause high pollution to the environment.To address these issues regarding lithium extraction from spodumene ore,this study investigated a novel method to process spodumene ore that comprises the extraction of Li from spodumene ore and the recovery of major Si-and Al-containing compounds.Specifically:direct vacuum carbothermal reduction of spodumene ore to extract Li while preparing Al-Si alloy and vacuum carbothermal reduction of spodumene ore by adding Fe2O_(3) to extract Li,preparation of Si-Fe alloy,recovery of Al_(2)O_(3).This was based on theoretical calculations and experimental methods.First,equilibrium compositions for the carbothermal reduction reac⁃tions of Al and Si oxides reported in previous studies based on the Outotec HSC Chemistry Software HSC6.0 were used to perform ther⁃modynamic simulations on both reduction processes.Second,experimental procedures considering those theoretical calculations were carried out for the two processes.Carbothermic reduction experiments were cond

关 键 词：锂辉石矿 碳热还原 真空 锂 铝 硅 

分 类 号：TF826.3[冶金工程—有色金属冶金]