纯碱副产物氯化钙的提纯实验研究

Experimental study on purifying by-product calcium chloride of soda ash

以提高纯碱副产物氯化钙的纯度为目的,采用过滤、重结晶、加氧化钙、斜发沸石吸附等除杂方法,进行了氯化钙提纯的实验研究。结果表明:在工业级氯化钙的基础上,通过提纯使氯化钙的含量提高7.3%(质量分数,下同),氯化钠的含量降低52%,氯化镁的含量降低84%,铁含量降低98%,并去除了铅和铜,最终产品中氯化钙、氯化钠、氯化镁、水不溶物、铅、铁、铜的含量均达到了食品级氯化钙的指标。

For the purpose of improving the purity of the by-product calcium chloride of soda ash production, the purification experiments were studied through adopting various impurity removal methods, such as filtering, recrystallization, adding cal- cium oxide, and clinoptilolite adsorption.Results showed that the content of CaC12 was increased by 7.3% （mass fraction, same as below）, the contents of NaC1, MgC12, and Fe was reduced by 52%, 84%, and 98%, respectively, on the basis of purification of industrial grade calcium chloride ;furthermore, Pb and Cu were also removed.The indexes, such as CaC12, NaC1, MgC12, wa- ter insoluble, Pb, Fe, and Cu of the final product all met the requirements of food grade calcium chloride.