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›› 2006, Vol. 6 ›› Issue (6): 903-906.

• 反应与分离 • 上一篇    下一篇

新型钾分子筛的表征及其对K+的交换性能

袁俊生,郭兆寿,张林栋   

  1. 天津市河北工业大学化工学院
  • 出版日期:2006-12-20 发布日期:2006-12-20

Characterization of New Type Molecular Sieve for Potassium and Its Exchange Capability to K+

YUAN Jun-sheng,GUO Zhao-shou,ZHANG Lin-dong   

  1. Dept. Chem. Eng. Hebei University of Technology
  • Online:2006-12-20 Published:2006-12-20

摘要: 通过扫描电镜、化学组成分析、X射线衍射和热重差热分析对自制的新型分子筛进行了表征,并测定了分子筛对纯钾溶液和海水中K+的交换容量及对K+的选择性系数. 结果表明,新型分子筛由76.25%的Na6Al6Si10O32×12H2O和23.75%的K2Al2Si3O10×3H2O两种物质混合构成,其硅铝比(摩尔比)为5.22;分子筛在350℃以内是稳定的,温度过高,内部结构被破坏;分子筛对纯钾溶液和海水钾离子的交换容量分别为100.30和55.10 mg/g,对海水中K+的选择性系数达到74.41,与改性天然沸石相比,对海水中K+的交换容量提高2倍,选择性系数提高3倍. 说明新型分子筛对K+具有很高的选择性,可用于从海水及含钾卤水中高选择性分离钾盐.

关键词: 钾, 分子筛, 表征, 离子交换性能

Abstract: The self-made molecular sieve for potassium was characterized by SEM, chemical composition analysis, XRD and TGA-DTA. And the exchange capacities of the molecular sieve to K+ in pure potassium solution and in seawater and the selectivity coefficients to K+ in seawater were determined respectively. The results showed that the molecular sieve is composed of the two components, 76.25% Na6Al6Si10O32×12H2O and 23.75% K2Al2Si3O10×3H2O, and the mole ratio of silicon to aluminum is 5.22, it is stable up to 350℃, but the internal structure is destroyed at the temperatures more than 350℃, the exchange capacities of the zeolite to K+ in pure potassium solution and seawater are 100.30 and 55.10 mg/g respectively, and the selectivity coefficient to K+ in seawater is 74.41, that is, compared with the modified natural clinoptilolite, the new type molecular sieve has an increase of 2 times in the exchange capacity to K+ in seawater and 3 times in the selectivity coefficient to K+ in seawater. Therefore, the molecular sieve has high selectivity to K+, and can be used to extract potash selectively from seawater and the brine containing potassium.

Key words: potassium, molecular sieve, characterization, ion exchange capability