Acta Phys. -Chim. Sin. ›› 2004, Vol. 20 ›› Issue (03): 306-308.doi: 10.3866/PKU.WHXB20040318

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Phase Transformation of Supersaturated Solution of MgO•3B2O3-H2O under Hydrothermal Condition

Zhou Jian-Guo;Yan Chang-Ling;Lu Yan;Gao Shi-Yang;Xia Shu-Ping   

  1. College of Chemistry and Environmental Science, Henan Normal University, Xinxiang 453002;Department of Chemistry, Lanzhou University 730000;Xi’an Branch, Institute of Salt Lake, Chinese Academy of Sciences, Xi’an 710043
  • Received:2003-07-09 Revised:2003-10-15 Published:2004-03-15
  • Contact: Zhou Jian-Guo

Abstract: Supersaturated solution of MgO•3B2O3-H2O was prepared and kept under hydrothermal condition at 120 ℃.The solid phases separated from MgO•3B2O3-H2O supersaturated solution were identified by means of chemical analysis, XRD and IR. The process was a phase transformation of Mg-borates. Two amorphous intermediate-products are 2MgO•3B2O3•5H2O and MgO•B2O3•3H2O and the final product is the crystalling 2MgO•B2O3•H2O.The mechanism of phase transformation was proposed and the function of MgSO4 in the supersaturated solution of MgO•3B2O3-18%MgSO4-H2O was discussed.

Key words: Hydrothermal condition, Supersaturated solution, Mg-borate, Phase transformation