物理化学学报 >> 2004, Vol. 20 >> Issue (11): 1335-1338.doi: 10.3866/PKU.WHXB20041110

研究论文 上一篇    下一篇

铬酸钠碳氨转化过程的相图分析

刘昌见;张懿   

  1. 中国科学院过程工程研究所,北京 100080; 石油大学(北京)中国石油天然气集团公司催化重点实验室,北京 102249
  • 收稿日期:2004-03-02 修回日期:2004-06-22 发布日期:2004-11-15
  • 通讯作者: 刘昌见 E-mail:chjliu@bjpeu.edu.cn

Phase Diagram Analysis of the Carbonation Process of Sodium Chromate and Ammonia Solution

Liu Chang-Jian;Zhang Yi1   

  1. Institute Process Engineering, Chinese Academy of Sciences, Beijing 100080; The Key Laboratory of Catalysis, China National Petroleum Corporation, University of Petroleum, Beijing 102249
  • Received:2004-03-02 Revised:2004-06-22 Published:2004-11-15
  • Contact: Liu Chang-Jian E-mail:chjliu@bjpeu.edu.cn

摘要: 研究了铬酸钠碳氨转化过程中Na+, NH4+// CrO42-, HCO3--H2O体系的溶解度和相图.根据溶解度和相图对铬酸钠的氨水溶液碳氨转化过程固相析出行为进行分析.结果表明: 相图中存在NaNH4CrO4·2H2O复盐结晶区,浓度较高的铬酸钠氨水溶液转化过程中NaC(HO)3、(NH4)2CrO4和NaNH4CrO4·2H2O结晶可能同时析出,形成混晶.为避免同时析出铬酸铵、碳酸氢钠结晶,铬酸钠氨水初始溶液浓度应稍低于相图中P2(P2′)对应的组成,即为1 g H2O中Na2CrO4 0.8633~1.1377 g,氨0.0611~0.0986 g.

关键词: 铬盐, 清洁工艺, 溶解度, 相图分析

Abstract: The solubility and phase diagram of Na+, NH4+// CrO42-, HCO3--H2O system are determined in this paper. According to the solubility and phase diagram, the solid phases in carbonation process of sodium chromate in ammonia solution are discussed. The results show that a crystalline zone of NaNH4CrO4·2H2O exists, NaHCO3, NaNH4CrO4·2H2O and (NH4)2CrO4 crystallize out in turn during carbonation process as the concentration of sodium chromate in ammonia water exceeds the concentration corresponding to P2(P2′) in phase diagram. Proper concentration is 0.8633~1.1377 g/g H2O for sodium chromate, 0.0611~0.0986 g/g H2O for ammonia, lower than the concentration corresponding to P2(P2′) plot. The NaHCO3 and NaNH4CrO4·2H2O crystals can be separated by hydrocyclone.

Key words: Chromates, Clean process, Solubility, Phase diagram