Abstract
The authors reported in their previous paper (This Journal, 24, 189-196 (1971)) the polythermic equilibrium diagrams of the five component system: Na, K, Mg Cl, SO4-H2O at the temperature ranging from 50° to 110°.
This paper reports the resuits of the study which the authors made on the equilibriums of the quinary reciprocal system. To obtain the basic data for a phase-rule analysis on the concentrating process of ion-exchange-membrane brine, the mixture of ion-exchange-membrane brine and salf-field brine, etc., the authors interpolated the compositions of liquid phases and the kinds of solid phases stable at 83stable at 83° and 110°C from the above-mentioned polytherms, and made up two new tables for these quinary systems.
These values were protted on the triangular cordinate (Jaeneck projection) and stereogeometric axis (D'Ans, projection), and the diagrams thus obtained were studied. As the result, the authors reached the following conclusion:
1. At 83°C, NaCl, loeweite (Na2SO4·MgSO4·5/2H2O) and langbeinite (K2SO4·2MgSO4) can coexist stably in the divariant system on the line connecting the monovariant points V and W.
2. On the diagram at 110°C, the area of langbeinite field was found to be about twice and that of loeweite about seven times larger than those in the diagrams of D'Ans.
3. At 83°C and 110°C, the most part of Na2SO4field on the diagrams of D'Ans was found to be occupied by d'ansite (MgSO4·3NaCl·9Na2SO4).
