Na_2B_4O_7-Na_2CO_3-NaHCO_3-NaBO_2-H_2O四元体系的等温溶度

Isothermal Solubility of Na_2B_4O_7-Na_2CO_3-NaHCO_3-NaBO_2-H_2O System at 25,35and 45℃

测定了四元体系Na2B4O7Na2CO3NaHCO3NaBO2H2O在25、35及45℃时的等温溶度和饱和溶液的折光率绘制了相应的溶度图和组成折光率图.体系在35和45℃时有异成分化合物-天然碱(Na2CO3·NaHCO3·2H2O)生成.这些结果有助于揭示含硼碱湖的固体盐矿成因,对有关盐卤存在的反应2Na2CO3Na2B4O7+H2O=4NaBO2+2NaHCO3,揭示了相化学规律.

Solubilities and refractive indices of saturated solutions of the syste m Na 2 B 4 O 7 -Na 2 CO 3 -NaHCO 3 -NaBO 2 -H 2 O have been investigated by isotherm al method at 25,35and 45℃.The comple x trona(Na 2 CO 3 ·NaHCO 3 ·2H 2 O)was found in the system,therefore,t here are 5monosaturated fields,7di saturated lines and 3invariant points:E 1t (Na 2 B 4 O 7 ·10H 2 O +NaBO 2 ·4H 2 O +Na 2 CO 3 ·nH 2 O),E 2t (Na 2 B 4 O 7 ·10H 2 O +Na 2 CO 3 ·NaHCO 3 ·2H 2 O +Na 2 CO 3 ·nH 2 O),E 3t (Na 2 B 4 O 7 ·10H 2 O +Na 2 CO 3 ·NaHCO 3 ·2H 2 O +NaHCO 3 ),at25℃,n=10;35℃,n=7;45℃,n=1.