物理化学学报 >> 2001, Vol. 17 >> Issue (11): 1021-1026.doi: 10.3866/PKU.WHXB20011112

研究论文 上一篇    下一篇

MgO•3B2O3-18%MgSO4-H2O过饱和溶液结晶动力学

马玉涛;夏树屏;高世扬   

  1. 中国科学院盐湖研究所西安二部,西安 710043;陕西师范大学应用化学研究所,西安 710062;青海大学化工学院,西宁 810016
  • 收稿日期:2001-04-06 修回日期:2001-08-13 发布日期:2001-11-15
  • 通讯作者: 高世扬 E-mail:gsyabc@pub.xaonline.com

Crystallization Kinetics of Mg-borates from MgO•3B2O3-18%MgSO4-H2O Supersaturated Solution

Ma Yu-Tao;Xia Shu-Ping;Gao Shi-Yang   

  1. Xi′an Branch,Institute of Salt Lakes,Chinese Academy of Sciences,Xi′an 710043;Institute of Applied Chemistry, Shaanxi Normal University,Xi′an 710062;College of Chemical Engineering, Qinghai University,Xining 810016
  • Received:2001-04-06 Revised:2001-08-13 Published:2001-11-15
  • Contact: Gao Shi-Yang E-mail:gsyabc@pub.xaonline.com

摘要: 针对我国盐湖硼资源的特点,模拟合成MgO•3B2O3-18%MgSO4-H2O过饱和溶液,在20 ℃恒温静置,跟踪结晶动力学过程.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,同时对结晶机制进行了探讨.结果表明,该结晶过程分两个阶段,第一阶段析出三方硼镁石(MgO•3B2O3•7.5H2O),第二阶段结晶析出章氏硼镁石(MgO•2B2O3•9H2O).

关键词: 硼酸盐, 过饱和溶液, 结晶动力学, 三方硼镁石, 章氏硼镁石

Abstract: The supersaturated solution of MgO•3B2O3-18%MgSO4-H2O was prepared and kept in a thermostat of (20±0.1) ℃.The crystallization processes of Mg-borates from the solution have been studied by the kinetic method .With the aid of simplex optinum method and digital integration as well as runge-kutta digital solution of differential equation system,the experimental data have been fitted and the kinetic parameters have been evaluated by computer.The crystallization kinetic equation has been given.There are two solid phases ,Macallisterite (MgO•3B2O3•7.5H2O) was firstly crystallized out from the solution and then hungchaoite (MgO•2B2O3•9H2O).The solid phases were identified by IR-spectra,X-ray powder diffraction and TG-DSC thermal analysis.

Key words: Borate, Supersaturated solution, Crystallization kinetics,  Macallisterite, Hungchaoite