Solubilities, Densities, and Refractive Indices of Ternary Systems (LiB5O8 + RbB5O8 + H2O) and (NaB5O8 + RbB5O8 + H2O) at 308.15 K and 0.1 MPa

• Published in: Russian journal of inorganic chemistry 2023-12, Vol.68 (13), p.1896-1902
• Main Authors: Su Zhang, Cheng, Hui-hui, Guo, Ya-fei, Wang, Shi-qiang
• Format: Article
• Language: English
• Subjects: Chemistry; Chemistry and Materials Science; Crystallization; Inorganic Chemistry; Liquid phases; Phase diagrams; Phase equilibria; Physicochemical Analysis of Inorganic Systems; Refractivity; Solid solutions; Solubility; Ternary systems
• ISSN: 0036-0236; 1531-8613
• DOI: 10.1134/S0036023623602222

Solid-liquid phase equilibria of the two ternary systems (LiB 5 O 8 + RbB 5 O 8 + H 2 O) and (NaB 5 O 8 + RbB 5 O 8 + H 2 O) were investigated at T = 308.15 K and p = 0.1 MPa by the isothermal solution equilibrium method. The experimental results show that the phase diagrams of the systems (LiB 5 O 8 + RbB 5 O 8 + H 2 O) and (NaB 5 O 8 + RbB 5 O 8 + H 2 O) at 308.15 K contain one invariant point, two univariant curves and two crystallization regions. The area of the crystallization region of RbB 5 O 8 ·4H 2 O is much larger than that of LiB 5 O 8 ·5H 2 O in the former system and that of NaB 5 O 8 ·5H 2 O in the latter system. Owing to the different solubilities of the salts in the aqueous systems, the solubility of RbB 5 O 8 in the solution decreased obviously with the increasing concentration of LiB 5 O 8 or NaB 5 O 8 in either ternary system, indicating that both have a relatively strong effect on the solubility of RbB 5 O 8 . It was found that both systems belong to the simple eutectic type, and neither double salts nor solid solutions were formed.