五元体系Li~+,K~+//CO_3~(2-),SO_4~(2-),B_4O_7~(2-) -H_2O在288 K时的介稳相平衡研究

采用等温蒸发法研究了五元体系Li~+,K~+//CO_3~(2-),SO_4~(2-),B_4O_7~(2-) -H_2O在288 K时的介稳相平衡关系,测定了该五元体系在288 K条件下的介稳平衡的溶解度和溶液密度,根据实验数据绘制了相应的介稳平衡相图和水图,相平衡研究结果表明该五元体系介稳相平衡中有复盐K_2SO_4·Li_2SO_4生成,其介稳相图(Li_2CO_3饱和)有4个共饱和点,9条单变量曲线,6个Li_2CO_3饱和的结晶区分别为LiBO_2·8H_2O,K_28_4O_7·4H_2O,K_2CO_3·3/2H_2O,K_2SO_4,Li_2SO_4·H_2O和复盐K_2SO_4·Li_2SO_4.

Metastable Equilibria in the Quinary System of Li~+, K~+//CO_3~(2-), SO_4~(2-),B_4O_2~(-7)-H_2O at 288 K

An experimental study on metastable equilibria at 288 K in the quinary system Li~+, K~+//CO_3~(2-),SO_4~(2-), B_4O_7~(2-)-H_2O was done by an isothermal evaporation method. Metastable equilibrium solubilities and densities of the solution were determined experimentally. Using the experimental data, the metastable equilibrium phase diagram and water diagram were plotted, respectively. The experimental results of the metastable equilibria show that the double salt K_2SO_4·Li_2SO_4 has been formed in the quinary system Li~+,K~+// CO_3~(2-),SO_4~(2-), B_4O_7~(2-)-H_2O at 288 K. In the metastable equilibrium phase diagram (saturated with Li_2CO_3), the quinary system has four invariant points, nine univariant curves, six fields of crystallization saturated with Li_2CO_3 LiBO_2·8H_2O, K_2B_4O_7·4H_2O, K_2CO_3·3/2H_2O, K_2SO_4, K_2SO_4·Li_2SO_4 and Li_2SO_4·H_2O].