四元交互体系Li+,K+//Cl-,B4O72--H2O 323 K相关系研究

采用等温溶解平衡法研究了四元交互体系L i+,K+//C l-,B4O72--H2O 323 K时的相关系。该四元交互体系323 K下的溶解度等温图含有4个盐类结晶相区、5条单变量线和2个无变量点。4个结晶相区分别对应于盐L i C.lH2O、KC、lL i2B4O7.3H2O和K2B4O7.4H2O的结晶区。2个无变量点标注为E和F。E点平衡固相为L iC l.H2O+KC l+L i2B4O7.3H2O,对应的平衡液相组成为w(L i+)6.55%,w(K+)2.16%,w(C l-)34.57%,w(B4O72-)1.89%;F点平衡固相为KC l+L i2B4O7.3H2O+K2B4O7.4H2O,对应的平衡液组成为w(L i+)2.35%,w(K+)2.37%,w(C l-)12.08%,w(B4O72-)4.56%。研究结果表明,该四元交互体系为简单共饱和型,体系中没有复盐和固溶体的形成。

Study on the phase equilibrium of reciprocal quaternary system Li+, K+//Cl-, B4O72--H2Oat323K

The equilibrium solubility of the(reciprocal) system Li~+,K~+//Cl~-,B_4O_7~(2-)-H_2O at 323 K was studied by isothermal dissolution equilibrium(method.) Based on the solubility data,the phase diagram was plotted,in which there are four crystallization fields,five univariant curves and two invariant points.At the invariant point E,the saturated solid salts are LiCl·H_2O,KCl and Li_2B_4O_7·3H_2O,and the corresponding composition of its(equilibrium) solution is w(Li~+) 6.55%,w(K~+) 2.16%,w(Cl~-) 34.57%,w(B_4O_7~(2-)) 1.89%.The saturated solid salts of invariant point F are KCl,Li_2B_4O_7·3H_2O and K_2B_4O_7·4H_2O,and the corresponding composition is w(Li~+) 2.35%,w(K~+) 2.37%,w(Cl~-) 12.08%,w(B_4O_7~(2-)) 4.56%.The experimental result shows that this system is of eutectic type,no(complex) salt or solid solution is formed.