物理化学学报 >> 2008, Vol. 24 >> Issue (02): 333-337.doi: 10.3866/PKU.WHXB20080226

研究简报 上一篇    下一篇

四元交互体系Cd2+, Na+//Cl-, SO42--H2O 298 K时的相平衡

黄艺; 倪师军; 桑世华; 王沛东   

  1. 成都理工大学地球化学系, 成都 610059
  • 收稿日期:2007-07-31 修回日期:2007-10-29 发布日期:2008-01-26
  • 通讯作者: 黄艺 E-mail:huangyi@cdut.cn

Phase Equilibrium of Quaternary Reciprocal System Cd2+, Na+//Cl-, SO42--H2O at 298 K

HUANG Yi; NI Shi-Jun; SANG Shi-Hua; WANG Pei-Dong   

  1. Department of Geochemistry, Chengdu University of Technology, Chengdu 610059, P. R. China
  • Received:2007-07-31 Revised:2007-10-29 Published:2008-01-26
  • Contact: HUANG Yi E-mail:huangyi@cdut.cn

摘要: 采用等温溶解平衡法研究了四元交互体系Cd2+, Na+//Cl-, SO2-4-H2O在298 K的相平衡关系. 研究发现, 该平衡体系存在Na2CdCl4·3H2O复盐相区, 平衡相图中有七条单变度曲线, 三个共饱和点和五个结晶相区. 其平衡固相的结晶区分别为Na2SO4、CdSO4、CdCl2·2.5H2O、Na2CdCl4·3H2O和NaCl. 该四元交互体系平衡液相的物化性质随着Cd2+浓度的增加呈现有规律的变化. 研究结果表明, 镉盐在该体系中的溶解度大, 迁移性强, 增加了土壤环境污染风险.

关键词: 镉; 四元交互体系; 等温溶解平衡法; 相平衡

Abstract: Phase equilibrium of quaternary system Cd2+, Na+//Cl-, SO2-4-H2O at 298 K was studied by isothermal method. The study showed that the quaternary system bearing Cd included Na2CdCl4·3H2O phase field, seven univariant curves, three co-saturation points and five crystal phase fields. The crystal fields of equilibrium solid phases were Na2SO4, CdSO4, CdCl2·2.5H2O, Na2CdCl4·3H2O and NaCl, respectively. The physico-chemical properties of solution in the quaternary system indicated regular change along with the increase of Cd2+ concentration. The results indicated that Cd salts possess quite high solubilities in the system studied, which means a strong transfer of Cd2+ and a high pollution risk of soil environment.

Key words: Cadmium, Quaternary reciprocal system, Isothermal method, Phase equilibrium