锂云母提锂工艺及脱氟技术研究进展

锂云母是我国重要的锂矿资源, 开发高效的提锂工艺对于保障锂行业可持续发展具有重要的研究意义。氟具有极强的电负性, 可以取代表界面羟基, 从而进入锂云母晶格, 在锂云母中含量可达5%~10%, 如何实现提锂过程中氟的深度脱除对于锂云母的清洁、高效提取具有重要意义。通过对典型的硫酸法、石灰石法、硫酸盐法、氯化焙烧法、压煮法和氟化学法等锂云母提锂工艺研究现状进行阐述, 充分探讨各主流提锂工艺的反应原理、工艺条件等, 客观分析总结工艺的优缺点, 并对目前脱氟技术的研究现状进行分析, 总结现有脱氟工艺的反应机理及脱氟装置改进方向。最后, 对锂云母整体提锂工艺的深度脱氟, 凝练出液相氟脱除的新思路, 旨在为锂云母清洁、高效提取提供重要的理论基础。 

A Review of Lithium Extraction from Lepidolite and Current Research Development of Fluorine Removal

Lepidolite is an important lithium resource in China. The development of efficient lithium extraction process is of great significance to ensuring the sustainable development of lithium industry. Due to the strong electronegativity of fluorine(F), about 5%~10% of F attacks the lepdolite lattice by taking interfacial hydroxyl groups. It is critical for the clean and effective utilisation lepidolite to accomplish the deep removal of fluorine during the lithium extraction process. Firstly, the typical methods to extract lithium from lepidolite were discussed such as sulfuric acid and limestone, sulfate, chloride roasting, pressure autoclave method and the fluorine chemical method. The reaction principle and technological conditions including the advantages and disadvantages of different methods were systematically discussed. Moreover, the current research development of defluorination was summarized such as the reaction mechanism and development of defluorination device. Finally, the deep fluorine removal, especially for fluorine in lithium containing liquid phase, was proposed as a new research direction, aiming at providing an important theoretical basis for clean and efficient lithium extraction of lepidolite.