退役锂电池回收废液制备磷酸锂工艺研究

Preparation of lithium phosphate from waste liquid of retired lithium batteries

鉴于锂电池报废量大、锂含量高,探讨从退役锂电池回收废液中利用锂资源。根据溶液高钠含锂、碱含量高的特性,采用磷酸钠沉淀法回收锂,系统研究了反应过程中各工艺参数对磷酸锂回收率、纯度及粒度的影响。结果表明反应温度为102℃,磷酸钠1.1倍理论用量,磷酸钠浓度350 g·L^(-1),加料速率5 mL·min-1,搅拌速率500 r·min-1,冷水洗1 L时,磷酸锂收率能达到92.63%,纯度(质量分数,下同)达到98.81%,产品达到彩色荧光粉用磷酸锂行业标准二级要求。该工艺能广泛应用于各种高钠含锂溶液,特别是从锂浓度较低的溶液中回收锂资源,不仅解决了退役锂电池废液排放问题,还为锂资源提取提供了新途径。

Consindering the large amount of discarded lithium batteries and the high content of lithium,lithium resources from the waste liquid of retired lithium batteries were studied.According to the charac-teristics of high sodium content and high alkali content in the solution,lithium was recovered by sodium phosphate precipitation method.The effects of various process parameters on the recovery yield,purity and particle size of lithium phosphate were systematically studied.The optimized process conditions were as follows:reaction temperature was 102℃,dosage of sodium phosphate was 1.1 of the theoretical a-mount,concentration of sodium phosphate was 350 g·L^(-1),feeding rate was 5 mL·min-1,stirring rate was 500 r·min-1,the cold water washing is 1 L.Under the optimized conditions,the precipitation yield of lithium phosphate was 92.63%,the purity of lithium phosphate was 98.81%.The products meet the in-dustry standard of lithium phosphate for color phosphor.This process can be widely used in various high-sodium lithium-containing solutions,especially in the recovery of lithium resources from solutions with low lithium concentration,which not only solves the problem of waste liquid discharge of retired lithium batteries,but also provides a new way for lithium resource extraction.