Chinese Journal of Applied Chemistry ›› 2016, Vol. 33 ›› Issue (3): 350-356.DOI: 10.11944/j.issn.1000-0518.2016.03.150242

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Measurement of the Metastable Zone of Sodium Perborate Tetrahydrate

YE Xuefangabc,YI Shouzhia,XIAO Qingguibc*(),SUN Randibc,TIAN Yingbc,XU Hongbinbc,ZHANG Yibc   

  1. aCollege of Material Science and Chemical Engineering,Tianjin University of Science and Technology,Tianjin 300457,China
    bNational Engineering Laboratory for Hydrometallurgical Cleaner Production Technology,Institute of Process Engineering,Chinese Academy of Sciences,Beijing 100190,China
    cKey Laboratory of Green Process and Engineering,Chinese Academy of Sciences,Beijing 100190,China
  • Received:2015-07-10 Accepted:2015-09-25 Published:2016-03-02 Online:2016-03-02
  • Contact: XIAO Qinggui
  • Supported by:
    Supported by the National Natural Science Foundation of China(No.21376251, No.21406233), the National High Technology Research and Development Program of China(No.2011AA060702), the National Basic Research Program of China(No.2013CB632600)

Abstract:

The metastable zone is one of the most important properties of the crystallization process. In the present study the solubility and supersolubility of sodium perborate tetrahydrate(SPT) in water were measured by the laser detection technique. The dependence of the solubility and supersolubility on the temperature, cooling rate, stirring rate and concentrations of additives was discussed carefully. The curves of solubility and supersolubility were obtained and the empirical equation of the solubility for sodium perborate was employed to fit the data of sodium perborate solubility. The experimental results show that the solubility of SPT increases with the increase of temperature, the stable area of SPT becomes narrower at higher temperature, and the metastable zone increases with the increase of cooling rate and decrease of stirring rate. Further results show that the metastable zone width(MZW) of SPT is remarkably affected by the concentrations of additive agents and a maximum metastable zone is obtained when the concentrations of sodium hexametaphosphate and sodium polyacrylate are 0.065% and 0.045%, respectively.

Key words: solubility, supersolubility, metastable zone, additives, sodium perborate