【摘要】 针对含锂相关水盐体系相平衡研究不够完善的问题,采用等温溶解平衡法研究四元体系Li⁺,Mg²⁺//SO₄^2-,B₄O₇^2--H₂O在273 K相平衡关系,并根据溶解度数据绘制相图。结果表明该体系属于简单交互四元体系,无复盐和固溶体生成。其相图包含2个共饱点,5条单变量曲线和4个结晶相区（分别是Li₂B₄O₇·3H₂O、Li₂SO₄·H₂O、MgB₄O₇·9H₂O和MgSO₄·7H₂O）。从相图中可以看出,MgB₄O₇所对应的相区最大,溶解度最小。对比该体系在不同温度下相图发现,随着温度升高MgSO₄和MgB₄O₇的结晶区明显减小,而Li₂B₄O₇和Li₂SO₄的结晶区明显增大,说明MgSO₄和MgB₄O₇的溶解度相较于Li₂B₄O₇和Li₂SO₄对温度变化更敏感。更多还原

【Abstract】 Phase equilibrium of water-salt systems containing lithium is not well studied. An isothermal dissolution equilibrium method was used to study phase equilibrium of Li⁺, Mg²⁺//SO₄^2-,B₄O₇^2--H₂O quaternary system at 273 K, and phase diagram was obtained. The results show that this quaternary system is a simple interactive quaternary system without double salt or solid solution formation. The phase diagram contains two invariant points, five univariant curves and four crystallization areas（corresponding to Li₂B₄O₇·3H₂O, Li₂SO₄·H₂O, MgB₄O₇·9 H₂O and MgSO₄·7H₂O）. The phase diagram shows that MgB₄O₇ has the largest phase region and the lowest solubility. Phase diagrams at different temperatures were compared and the results show that with the increase of temperature, the crystallization regions of MgSO₄ and MgB₄O₇ decrease significantly, while the crystallization regions of Li₂B₄O₇ and Li₂SO₄ increase significantly. The results show that the solubility of MgSO₄ and MgB₄O₇ is more sensitive to temperature than that of Li₂B₄O₇ and Li₂SO₄.更多还原