(Solid+Liquid) Equilibria in the Quaternary System Na₂B₄O₇‐MgB₄O₇‐K₂B₄O₇‐H₂O at 288 K

Abstract

Abstract (Solid+Liquid) phase equilibria in the quaternary system Na 2 B 4 O 7 ‐MgB 4 O 7 ‐K 2 B 4 O 7 ‐H 2 O at 288 K were studied experimentally using the method of isothermal solution saturation. Solubility of any single salt in the solution of the quaternary system was determined experimentally. Based on the experimental data achieved, the phase diagram and water content diagram of the quaternary system were constructed, respectively. In the phase equilibrium diagram of the quaternary system Na 2 B 4 O 7 ‐MgB 4 O 7 ‐K 2 B 4 O 7 ‐H 2 O at 288 K, there are one invariant point E , three univariant curves E 1 E , E 2 E and E 3 E , and three fields of crystallization corresponding to Na 2 B 4 O 7 ·10H 2 O, K 2 B 4 O 7 ·4H 2 O and MgB 4 O 7 ·9H 2 O. The experimental results show that potassium borate (K 2 B 4 O 7 ·4H 2 O) have higher solubilities than the magnesium borate and sodium borate in the quaternary system Na 2 B 4 O 7 ‐MgB 4 O 7 ‐K 2 B 4 O 7 ‐H 2 O at 288 K.