吸附法提取煤矸石中锂的工艺

Extraction of lithium from coal gangue by manganese ion sieve adsorption

平朔煤矸石中锂元素含量较高,寻找适合的提取方法具有重要的研究价值和应用前景。本文利用盐酸酸浸活化的煤矸石使锂溶到溶液中,采用自制的锰系离子筛对溶液中的锂进行吸附,实现锂的回收。主要考察了活化配比、活化温度、酸浸温度、酸浸体积、酸浸浓度等因素对煤矸石中锂浸出率的影响,通过单一控制变量法确定了最佳焙烧和浸出工艺条件,使锂的浸出率达到79%以上;研究了不同温度和时间对合成离子筛的影响,利用X射线衍射仪、扫描电镜、电感耦合等离子体发射光谱仪对离子筛晶型以及吸附性能进行表征,结果显示800℃下煅烧15h可以合成晶型完整的LiMn2O4尖晶石,且在溶液pH=14固液比1∶500时H型离子筛吸附容量达到了24mg/g;ICP数据处理结果表明H型离子筛对活化的煤矸石酸浸液中的锂吸附率达到了99%以上。

Due to the high content of lithium in the Pingshuo coal gangue, it is of great research value to find a suitable lithium extraction method. In this paper, the method of acid leaching with hydrochloric acid is used to dissolve the lithium of coal gangue into the solution, and then the lithium in the solution is adsorbed by a self-made manganese ion sieve to realize the recovery of lithium. The effects of activation ratio, activation temperature, acid leaching temperature, acid leaching volume and acid leaching concentration on lithium leaching rate in coal gangue were investigated. The optimum calcination and leaching conditions were determined by a single controlled variable method to achieve a dissolution rate of lithium of over 79%. Moreover,the effects of temperature and time on the formation of ion sieves were studied. The crystal form and adsorption properties of the ion sieve were characterized by XRD, SEM and ICP-OES. The results showed that the crystalline LiMn2 O4 spinel was synthesized by calcination at 800℃for 15 h. The adsorption capacity of the H-type ion sieve reached 24 mg/g under the condition of a solution pH of 14 and a solid-liquid ratio of 1∶500. The results of ICP showed that the adsorption rate of lithium in the activated coal gangue acid leaching solution by H-type ion sieve was over 99%.