The Solubilities and Physicochemical Properties of the Aqueous Quaternary System Li+, K+, Rb+//Borate–H2O at 348 K

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• 作者：Fengping Yan ; Xudong Yu ; Qinghong Yin ; Yujuan Zhang ; Ying Zeng
• 刊名：Journal of Chemical & Engineering Data
• 出版年：2014
• 出版时间：January 9, 2014
• 年：2014
• 卷：59
• 期：1
• 页码：110-115
• 全文大小：306K
• ISSN：1520-5134

文摘

The solubility values and physicochemical properties (pH values, refractive indices, and densities) of electrolyte mixtures in quaternary system containing lithium, potassium, rubidium, and borate were investigated at 348 K by isothermal dissolution method. The space phase diagram, the planar projection diagram, the water content diagram, and the diagrams of physicochemical properties depending on the composition were obtained using the measured data. The phase diagram of this quaternary system contains one invariant point, three univariant curves, and three single salts corresponding to lithium tetraborate trihydrate (Li₂B₄O₇路3H₂O), potassium tetraborate tetrahydrate (K₂B₄O₅(OH)₄路2H₂O), and rubidium pentaborate tetrahydrate (RbB₅O₆(OH)₄路2H₂O). This quaternary system is of a simple cosaturation type, no double salt or solid solution formed. The scope of areas of crystallization of salts is such that RbB₅O₆(OH)₄路2H₂O > Li₂B₄O₇路3H₂O > K₂B₄O₅(OH)₄路2H₂O, which demonstrates the salt RbB₅O₆(OH)₄路2H₂O can be more easily separated from the solution than the other coexisting salts at 348 K. The physicochemical properties of the solutions at equilibrium on the univariant curve CE increase obviously with increasing J盲necke index, J(K₂B₄O₇); whereas on the univariant curve AE or BE, the physicochemical properties change slightly along with the changes of J(K₂B₄O₇).