四元体系Na^+∥Cl^-,CO_3^(2-),B_4O_7^(2-)-H_2O 273K介稳相平衡研究  

METASTABLE PHASE EQUILIBRIUM OF THE QUATERNARY SYSTEM Na^+∥Cl^-,CO_3^(2-),B_4O_7^(2-)-H_2O AT 273K

作　　者：王瑞麟[1] 曾英[1] 

机构地区：[1]成都理工大学材料与化学化工学院,四川成都610059

出　　处：《矿物岩石》2008年第4期109-112,共4页Mineralogy and Petrology

基　　金：国家自然科学基金(40673050);教育部博士点基金(20070616008);四川省学术和技术带头人培养基金(2008-140)

摘　　要：采用等温蒸发法研究简单四元体系Na+∥Cl-,CO32-,B4O72--H2O273K时的介稳相平衡,并测定该体系273K平衡液相中各组分的溶解度及密度,该体系的介稳相图和密度组成图显示:该四元体系在273K时的相图由3条溶解度单变量线、3个结晶区及1个共饱和点组成。体系属简单共饱型,无复盐或固溶体形成,3个结晶区分别对应单盐Na2CO3·10H2O,NaCl和Na2B4O7·10H2O。共饱点E处于Na2CO3·10H2O,NaCl及Na2B4O7·10H2O3盐共饱和,所对应的平衡液相组成为w(Na2CO3)=6.81%,w(NaCl)=21.69%,w(Na2B4O7)=0.65%,w(H2O)=70.85%。研究体系在273K下,Na2CO3·10H2O是碳酸钠盐的唯一析出形式,且硼酸钠对碳酸钠有盐析作用。The metastable phase equilibrium of the quaternary system Na＋//Cl-,CO3^2-,B4O7^2--H2O was studied at 273 K by isothermal evaporation method, the solubility and density of the equilibrium solution of this system were determined and the metastable equilibrium phase diagram was plotted in line with the experimental data. The phase diagram of the system consists of three univariant curves, three crystallization fields and one invariant point. This system is of eutectic type, no double salt or solid solution was formed. The four crystallization fields were corresponding to single salt Na2CO3·10H2O,NaCl andNa2B4O7·10H2O, respectively. Invariant point E was saturated with saltsNa2CO3·10H2O,NaCl and NaB4O7·10H2O3, the mass fraction composition of the equilibrium solution corresponding to E is zw（Na2CO3）=6.81%,w（NaCl）=21.69%,w（Na2B4O7）=0.65%,w（H2O）=70.85% The Na2CO3 · 10H2O is the only crystal form of the salt sodium carbonate in this system at 273 K. Na2B4O7 has salting out effect to Na2CO3 in the solution.

关 键 词：四元体系 介稳相平衡 碳酸盐 273 K 

分 类 号：O642.42[理学—物理化学]