CIESC Journal

• 分离工程 • 上一篇    下一篇

盐析结晶法分离铬酸钾

徐红彬 张懿 尤海侠   

  1. 中国科学院过程工程研究所
  • 出版日期:2007-04-05 发布日期:2007-04-05

Separation of potassium chromate by salting-out crystallization

  

  • Online:2007-04-05 Published:2007-04-05

摘要: 关联了不同温度下K2CrO4在K2CrO4-KOH-H2O体系中的溶解度数据,分析了从K2CrO4-KOH-H2O体系中通过盐析结晶方式分离K2CrO4的可能性;通过K2CrO4-KOH-H2O体系中K2CrO4的盐析结晶实验,得出了初级成核现象发生时,体系的最大过饱和度与过饱和速率之间的动力学关系式及结晶过程中盐析剂浓度、盐析结晶终点K2CrO4收率、溶液体积等工艺参数间的关系,探讨了以KOH作为盐析剂,采用盐析结晶方法从K2CrO4-KOH-H2O体系中分离提纯K2CrO4的可行性,为K2CrO4的高效分离提供了一种新思路。

Abstract: The green manufacturing process for chromium compounds, which was proposed by the Institute of Process Engineering, Chinese Academy of Sciences, has spawned a lot of interests in the chromate production industry all over the world. The separation of the intermediate product K2CrO4 is one of the bottleneck units in the green manufacturing process. This work is to seek a new approach to the separation of K2CrO4. The solubility data of K2CrO4 in the K2CrO4-KOH-H2O system were regressed and processed. The possibility of separating K2CrO4 from the K2CrO4-KOH-H2O system through salting-out crystallization with a salting-out reagent was investigated. The kinetic relationship between the maximum supersaturation and supersaturation rate during nucleation was obtained.The relationship among the concentration of the salting-out reagent, the recovery efficiency of K2CrO4 and the solution volume of the final system was also obtained. The feasibility of the separation of K2CrO4 from the K2CrO4-KOH-H2O system through salting-out crystallization with KOH as the salting-out reagent was explored.This method provides a promising approach to the highly efficient separation of K2CrO4.