Abstract

The isothermal dissolution method was used to study the stable phase equilibria in the quinary system Li⁺,Na⁺,Mg²⁺//Cl^–,B₄\({\text{O}}_{7}^{{2 - }}\)–H₂O at 273 K. The dry salt diagram, sodium diagram and water diagram in the quinary system were plotted respectively when Sodium chloride (NaCl) is saturated. The experimental results show that a complex salt lithium carnallite (LiCl·MgCl₂·7H₂O) is formed in the system. The dry base diagram of this system saturated with NaCl consists of four invariant points, nine univariate curves, and six crystalline regions. The crystalline regions are lithium borate trihydrate (Li₂B₄O₇·3H₂O), sodium borate decahydrate (Na₂B₄O₇·10H₂O), magnesium borate nonahydrate (MgB₄O₇·9H₂O), lithium chloride dihydrate (LiCl·2H₂O), magnesium chloride hexahydrate (MgCl₂·6H₂O), and the double salts lithium carnallite (LiCl·MgCl₂·7H₂O), among which sodium borate decahydrate (Na₂B₄O₇·10H₂O) has the largest crystalline area that shows that Na₂B₄O₇·10H₂O is the easiest to precipitate.

中文翻译：

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五元体系中的稳定相平衡 Li+,Na+,Mg2+//Cl–,B4 $${\text{O}}_{7}^{{2 - }}$$ –H2O at 273 K

摘要

采用等温溶解法研究了Li ⁺ ,Na ⁺ ,Mg ²⁺ //Cl ^– ,B ₄ \({\text{O}}_{7}^{{2 - }}\) –H ₂ O at 273 K。分别绘制了氯化钠 (NaCl) 饱和时五元体系中的干盐图、钠图和水图。实验结果表明，体系中形成了络盐锂光卤石(LiCl·MgCl ₂ ·7H ₂ O)。该系统的 NaCl 饱和干基图由四个不变点、九个单变量曲线和六个结晶区域组成。结晶区域是三水硼酸锂（Li₂ B ₄ O ₇ ·3H ₂ O）、十水硼酸钠（Na ₂ B ₄ O ₇ ·10H ₂ O）、九水硼酸镁（MgB ₄ O ₇ ·9H ₂ O）、二水氯化锂（LiCl·2H ₂ O） )、六水氯化镁(MgCl ₂ ·6H ₂ O)、光卤石复盐锂(LiCl·MgCl ₂ ·7H ₂ O)，其中十水硼酸钠(Na ₂ B ₄ O ₇ ·10H ₂O)的结晶面积最大，说明Na ₂ B ₄ O ₇ ·10H ₂ O最容易析出。