重铬酸钠溶液分解碳酸钙制取铬酸钙  

Manufacture of Calcium Chromate from Decomposition of Calcium Carbonate in Aqueous Sodium Dichromate Solution

作　　者：王天贵[1] 李佐虎[1] 

机构地区：[1]中国科学院过程工程研究所

出　　处：《过程工程学报》2005年第2期166-169,共4页The Chinese Journal of Process Engineering

基　　金：中国科学院知识创新工程重大项目(编号:KCCX1-SW-22)

摘　　要：介绍了一种制取铬酸钙的新方法,利用重铬酸钠溶液分解碳酸钙,可以得到高纯度的铬酸钙. 实验表明,温度和浓度是影响碳酸钙分解的关键因素,当重铬酸钠浓度大于60%、重铬酸钠与碳酸钙摩尔比大于1.05:1时,常压沸腾条件下即可完全分解碳酸钙,制得纯度99.5%的铬酸钙,收率接近100%. 分解过程中产生的二氧化碳气体可用于碳化分离铬酸钙后的铬酸钠溶液再生重铬酸钠,循环利用. 新方法工艺简单、产品纯度和收率都较高,无环境污染.There are various processes known for production of calcium chromate, which suffer from inherent disadvantages such as poor quality and severe pollution. A novel process for the manufacture of calcium chromate was presented in this paper. It is shown that calcium carbonate can be decomposed in aqueous sodium dichromate solution and transformed to calcium chromate at ambient pressure and boiling temperature. Both reaction temperature and concentration of sodium dichromate are the main factors controlling the decomposition of calcium carbonate. Under the conditions of the concentration of sodium dichromate≥60% and the molar ratio of sodium dichromate to calcium carbonate≥1.05:1, the purity of calcium chromate can reach 99.5% and the yield approaches to 100%. The carbon dioxide and aqueous sodium chromate solution produced during the decomposition of calcium carbonate can be recycled and no waste is discharged.

关 键 词：铬酸钙 碳酸钙 重铬酸钠 分解 制备 

分 类 号：TQ136.1[化学工程—无机化工]