Li^(+)、Na^(+)、k^(+)、SO_4(2-)-H_(2)O体系相图在MVR蒸发过程的应用研究

Application research of Li^(+),Na^(+),k^(+),SO_(4)^(2-)-H_(2)O system phase diagram in MVR evaporation process

工业上硫酸法矿石提锂生产碳酸锂的副产品是元明粉。为了解决元明粉生产环节MVR蒸发过程中出现的硫酸锂与硫酸钠共晶问题,采取了如下措施:首先,结合生产MVR流程实际取样数据,利用Li^(+)、Na^(+)、k^(+)、SO_4(2-)-H_(2)O体系相图进行理论分析,利用火焰光度计、原子吸收分光光度计及XRD等化学分析手段,综合分析证明了元明粉MVR蒸发过程中硫酸锂与硫酸钠共晶复盐的存在。其次,结合MVR设备结构及生产工艺,提出了硫酸锂和硫酸钠共晶造成元明粉产品杂质锂含量超标问题的解决方法。

In industry,the by-product of extracting lithium from ore to produce lithium carbonate is the sodium sulfate pow-der.In order to solve the current problem of lithium sulfate and sodium sulfate eutectic during MVR evaporation,the following measures were taken:Firstly,combining with the actual sample data of MVR production process,the phase diagram of Li^(+),Na^(+),k^(+),SO42--H_(2)O system was theoretically analyzed,and the existence of lithium sulfate and sodium sulfate eutectic com-plex salts in the evaporation process of MVR was proved and comprehensively analyzed by chemical analyzed means of flame photometer,atomic absorption spectrophotometer and XRD.Secondly,combining with the MVR equipment structure and pro-duction process,a solution to the problem of excessive lithium impurities in sodium sulfate production caused by lithium sul-fate and sodium sulfate eutectic was put forward.