一种氢氧化钠母液中提纯单水氢氧化锂晶体的工艺方法

The Method for Purifying LiOH Monohydrate Crystal in Mother Liquor of NaOH

在单水氢氧化锂生产中控制杂质含量成为此工艺的关键点之一,通过电解法生产出单水氢氧化锂混合大量氢氧化钠。单水氢氧化锂和氢氧化钠属于水溶性物质,通过二者溶解度不同进行蒸发结晶、提纯、锂钠分离。通过控制氢氧化钠、氢氧化锂混合碱在蒸发结晶过程中上清液密度,浓缩倍数,在氢氧化钠母液中单水氢氧化锂晶体先析出。上清液密度过低,单水氢氧化锂收率低。上清液密度过大,蒸发器气液分离室出现起沫现象,对于后期产品提纯钠离子去除率较低。

Controlling the impurity content in the production of lithium hydroxide monohydrate has become one of the key points of this process.Lithium hydroxide monohydrate is mixed by electrolysis to produce a large amount of sodium hydroxide.Lithium hydroxide monohydrate and sodium hydroxide are water-soluble substances,which are evaporated and crystallized by the solubility of them,and purified,separated by lithium and sodium.By controlling the sodium hydroxide lithium hydroxide mixed alkali in the evaporation crystallization process,the supernatant density,concentration multiple,in the sodium hydroxide mother liquor lithium hydroxide monohydrate crystals first precipitated.The supernatant liquid density is too low,and the yield of lithium hydroxide monohydrate is low.The density of the supernatant liquid is too large,and the foaming phenomenon occurs in the vapor-liquid separation chamber of the evaporator,and the sodium ion removal rate is low for the later product purification.