高等学校化学学报 ›› 2002, Vol. 23 ›› Issue (9): 1753.

• 研究论文 • 上一篇    下一篇

盐卤硼酸盐化学(非汉字字符)——MgO·nB2O3-18%MgCl2-H2O过饱和溶液20℃结晶动力学

朱黎霞, 高世扬, 郝志显, 夏树屏   

  1. 中国科学院青海盐湖研究所西安二部, 西安 710043
  • 收稿日期:2001-08-13 出版日期:2002-09-24 发布日期:2002-09-24
  • 通讯作者: 高世扬(1931年出生),男,研究员,中国科学院院士,从事成盐元素化学研究.E-mail:gsyabc@pub.xaonline.com E-mail:gsyabc@pub.xaonline.com
  • 基金资助:

    国家自然科学基金(批准号:29971032)资助

Chemistry of Borate(非汉字字符)——Crystallization Kinetics of Mg-borates from MgO·nB2O3-18%MgCl2-H2O Supersaturated Solution at 20 ℃

ZHU Li-Xia, GAO Shi-Yang, HAO Zhi-Xian, XIA Shu-Ping   

  1. Xi′an Branch, Qinghai Institute of Salt Lakes, Chinese Academy of Sciences, Xi′an 710043, China
  • Received:2001-08-13 Online:2002-09-24 Published:2002-09-24

摘要: 用结晶动力学方法对不同摩尔比的MgO/B2O3在摩尔分数为18%MgCl2-H2O中的过饱和溶液在20℃的结晶动力学过程进行了研究.n(MgO)/n(B2O3)=1/1和1/1.5时分别结晶析出2MgO·2B2O3·MgCl2·14H2O和2MgO·3B2O3·15H2O(多水硼镁石).n(MgO)/n(B2O3)=1/2时依次结晶析出MgO·3B2O3·7.5H2O,MgO·2B2O3·9H2O和2MgO·3B2O3·15H2O(多水硼镁石)3种固相.n(MgO)/n(B2O3)=1/3时结晶析出不同结晶水的六硼酸镁MgO·3B2O3·7H2O和MgO·3B2O3·7.5H2O.析出固相采用X射线粉末衍射、红外光谱和热分析进行物相鉴定.拟合并给出结晶动力学方程,同时对水合镁硼酸盐的结晶反应机理进行了探讨.

关键词: 结晶动力学, 过饱和溶液, 镁硼酸盐

Abstract: The MgO·nB2O3(n=1, 1.5, 2 and 3)-18%MgCl2-H2O supersaturated solution system were prepared and kept at 20 ℃. The crystallization processes of different hydrated Mg-borates from MgO·nB2O3-18%MgCl2-H2O supersaturated solution have been studied by kinetic method and the crystallization kinetic equations were fitted with the experimental data by computer. There were five solid phases, 2MgO·2B2O3·MgCl2·14H2O, 2MgO·3B2O3·15H2O, MgO·2B2O3·9H2O, MgO·3B2O3·7.5H2O and MgO·3B2O3·7H2O in the title system. All the solid phases were identified by IR-spectra, X-ray powder diffraction and TG-DTG-DSCthermal analysis.

Key words: Crystallization kinetics, Supersaturated solution, Mg-borate

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