苦卤石灰法生产氢氧化镁的废液再利用

Reusing of residual liquor in the production of magnesium hydroxide by lime-brine method

苦卤-石灰法生产氢氧化镁过程中产生大量提镁废液,提镁废液中含有氯化钙、氯化钠、氯化钾等。将苦卤、提镁废液掺兑,可生产副产品硫酸钙。对影响钙离子向硫酸钙转化的各种因素及反应后产物二水硫酸钙的纯化处理进行了研究。在此基础上,确定了工业生产状态下的操作条件,并投入了实际运行。新工艺不仅实现了提镁废液的有效利用,同时也对制盐及苦卤综合利用,特别是对氯化钾的提取创造了有利条件。

There is large quantity of waste liquor produced, after extracting magnesium in the production of magnesium hydroxide with lime -brine method. In this kind of liquor, there contains calcium chloride, sodium chloride and potassium chloride etc. The sideline product calcium sulphate will be produced by the mixing of brine and waste liquor. The various factors affecting the chemical transform from Ca^2＋ to calcium sulphate and the purification for the resultant of reaction （ i. e. calcium sulphate dihydrate） were studied. Based on the research results,the industrial operating conditions were confirmed and which have been put into practice. The new technology not only realized the full utilization of the waste liquor after extracting magnesium, but also provided favorable conditions to the comprehensive utilization of brine and salt - manufacturing, especially for the extraction of potassium chloride.