提钾母液制备氯化镁的绿色工艺开发与优化  

Development and optimization of green preparation process of magesium chloride from residual solution of potassium chloride plant

作　　者：王林[1] 王静康[1] 鲍颖[1] 何运良[1] 王彦飞[1] 

机构地区：[1]天津大学化工学院,天津300072

出　　处：《现代化工》2008年第1期58-61,共4页Modern Chemical Industry

摘　　要：老挝万象地区钾、镁盐矿溶浸液提取氯化钾后残留的母液中氯化镁质量分数高于25%,氯化钾、氯化钠质量分数之和小于5%,硫酸根离子、溴离子和钙离子含量极其微少,根据这一特点并结合相图,设计了一段蒸发除钾、钠盐,二段蒸发制取氯化镁的工艺路线。一段蒸发后析出的钾、钠盐杂质通过提钾工段回收,不仅提高了盐矿中氯化钾的提取率,同时实现了氯化镁生产过程的"零"排放,因此所开发工艺符合绿色化工标准。根据优化工艺得到的氯化镁产品达到工业级氯化镁质量标准。A preparation process of magnesium chloride production from residual solution of potassium chloride plant is designed and optimized, which comes from the leach solution of potash mine in Vientiane, I_aos. The residual solution contains magnesium chloride with the mass fraction above 25%, potassium chloride and sodium chloride below 5% together and extremely little portion of other ions like Br-, SO4^2- or Ca^2＋. The process consists of two parts： first evaporation-cooling operation to remove potassium chloride and sodium chloride, and the second evaporation-cooling crystallization procedure to produce magnesium chloride. The crystallized impurity-salts carnallite and sodium chloride are recycled to recover potassium salt,and the extraction efficiency of potassium chloride is increased. The whole process is zero discharge and fulfills the requirements of green chemical industry, and magnesium chloride produced by the green process is up to the industrial specification.

关 键 词：氯化镁 两段蒸发 冷却结晶 绿色工艺 

分 类 号：TQ014[化学工程] TQ028.61