2MgO·2B_2O_3·MgCl_2·14H_2O-7.8%H_3BO_3-H_2O体系多温相关系研究

Phase Relation of 2MgO·2B_2O_3·MgCl_2·14H_2O-7.8%H_3BO_3-H_2O System at Various Temperatures

研究了 2 Mg O· 2 B2 O3 · Mg Cl2 · 1 4 H2 O在不同温度下的 7.8% H3 BO3 水溶液中的相转化产物及其溶解度 . IR,XRD,TG及化学分析表明 ,相转化产物在 0～ 2 2℃范围内为 Mg O· 2 B2 O3 · 9H2 O;2 2～ 6 8℃为Mg O· 3B2 O3 · 7.5 H2 O;6 8～ 95℃为 Mg O· 3B2 O3 · 7H2 O;95～ 98.8℃为 Mg O· 3B2 O3 · 5 H2 O;1 0 0～ 1 1 0℃为 Mg O· B2 O3 · 3H2 O;1 1 0～ 1 2 0℃为 2 Mg O· B2 O3 · 2 H2 O;1 2 0～ 1 70℃为 2 Mg O· B2 O3 · 1 .5 H2 O;1 70～ 2 0 0℃为 2 Mg O·B2 O3 ·H2 O.提出了相转化反应原理 .

The phase relation of 2MgO·2B 2O 3·MgCl 2·14H 2O-7.8%H 3BO 3-H 2O system at various temperatures has been studied by FTIR spectroscopy, XRD, TG, as well as chemical analyses. The phase transformation product is MgO·2B 2O 3·9H 2O at 0-22 ℃, MgO·3B 2O 3·7.5 H 2O at 22-68 ℃, MgO·3B 2O 3·7H 2O at 68-95 ℃, MgO·3B 2O 3·5H 2O at 95-98.8 ℃, MgO·B 2O 3·3H 2O at 100-110 ℃, 2MgO·B 2O 3·2H 2O at 110-120 ℃, 2MgO·B 2O 3·1.5H 2O at 120-170 ℃, and 2MgO·B 2O 3·H 2O at 170-200 ℃, respectively. The mechanisms of dissolution and phase transformation have been proposed and discussed.