碳酸锂晶体团聚现象及调控方法  

Agglomeration phenomenon and regulation method of lithium carbonate crystal

作　　者：张志强[1] 成春春[1] 左硕 周娜 王佳琴 覃冬兰 ZHANG Zhiqiang;CHENG Chunchun;ZUO Shuo;ZHOU Na;WANG Jiaqin;QIN Donglan(College of Chemical Engineering,Qinghai University,Xining 810016,Qinghai,China)

机构地区：[1]青海大学化工学院,青海西宁810016

出　　处：《化工进展》2024年第12期6645-6661,共17页Chemical Industry and Engineering Progress

基　　金：国家自然科学基金(21968026);青海省科技厅项目(2023-ZJ-721)。

摘　　要：氯化锂与碳酸钠反应结晶是制备碳酸锂最主要的方法,本研究以提高碳酸锂收率、降低其钠含量以及获得良好粒径分布为目标,采用单因素法获得的较优的实验条件为:反应温度80℃,搅拌器转速600r/min,氯化锂浓度3.20mol/L,采用正加料的方式,晶种加入量2.00g/L,晶种粒径控制在小于54μm,超声功率100W,超声时间120min。反应中加入超声波后可有效避免出现大团聚体,在保证碳酸锂收率无明显降低的情况下,其钠含量降低了1个数量级,粒径明显变小且粒径分布更窄。以碳酸锂收率和钠含量为指标,选择反应温度、晶种加入量和超声功率进行响应面分析,拟合得到碳酸锂收率模型的相关系数R2=0.9784,其钠含量拟合模型的相关系数R2=0.9588,模型的预测值与实测值的相关性好;碳酸锂晶体团聚在实验的粒径范围内符合Thompson模型。通过研究获得优化的工艺参数可以为碳酸锂生产提供依据,并为产品质量的提高提供指导。Reaction crystallization using lithium chloride and sodium carbonate as raw materials is the main method for preparing lithium carbonate.To improve the yield of lithium carbonate,reduce its sodium content and obtain a narrow particle size distribution,a single-factor method was used to obtain a range of optimal experimental conditions.The experimental results showed that when the reaction crystallization temperature was 80℃,the stirrer speed was 600r/min,the lithium chloride concentration was 3.20mol/L,the positive feeding method was used,the seed crystal addition amount was 2.00g/L,the seed crystal particle size was controlled to be less than 54μm and the ultrasonic power was 100W,the obtained lithium carbonate had high yield,low Na content and narrow particle size distribution.In order to further optimize the experimental conditions to improve the lithium carbonate yield and reduce the sodium content in lithium carbonate,the Design Expert 13.0 software was used to select the reaction temperature,seed addition amount and ultrasonic power for a 3-factor 3-level by response surface analysis.The fitted yield equation was with a fitted correlation coefficient R2=0.9784.The fitted equation for the sodium content in lithium carbonate was with a correlation coefficient R2=0.9588.The correlation between the predicted value and the measured value was good.The conditions obtained after optimization could be verified to obtain a lithium carbonate yield of greater than 85%with sodium content controlled below 0.30mg/g Li2CO3.The lithium carbonate crystal agglomeration within the experimental particle size range was in agreement with the Thompson model,which could provide assistance for the design of the crystallizer.The experimental conditions obtained through research could provide a basis for adjusting process parameters for lithium carbonate production and guidance for improving product quality.

关 键 词：碳酸锂 团聚 晶种 超声 响应面 

分 类 号：TQ028.4[化学工程]