水热条件硼酸镁盐过饱和水溶液的相转化

Phase Transformation of Supersaturated Solution of MgO·3B_2O_3-H_2O under Hydrothermal Condition

针对中国盐湖硼资源特点,模拟合成MgO·3B2O3-H2O过饱和溶液,在120℃水热条件下对固相析出的过程进行跟踪.析出固相采用化学分析方法、X射线衍射、红外光谱进行物相鉴定.对析出固相的相转化反应机理进行了探讨,结合有关实验分析了MgSO4对固相析出的影响.

Supersaturated solution of MgO· 3B2O3-H2O was prepared and kept u nder hydrothermal condition at 120 ℃ .The solid phases separated from MgO· 3B2 O3-H2O supersaturated solution were identified by means of chemical analysis,X RD and IR.The process was a phase transformation of Mg-borates.Two amorphous i ntermediate-products are 2MgO· 3B2O3· 5H2O and MgO· B2O3· 3H2O and the fin al product is the crystalling 2MgO· B2O3· H2O.The mechanism of phase transform ation was proposed and the function of MgSO4 in the supersaturated solution of M gO· 3B2O3-18% MgSO4-H2O was discussed.