In the reciprocal salt pair Li2, K2, Cl2, SO4, and water, at 25 °C there are large areas in which potassium sulphate and potassium lithium sulphate (KLiSO4) are separately in equilibrium with solution. Two incongruent invariant points exist. At one of these the composition of the solution is 0.917 mole fraction chloride, 0.437 mole fraction lithium, and 19.4 moles of water per total mole of salt, the equilibrium solid phases being potassium chloride, potassium sulphate, and the double salt. At the second, the composition of the solution is 0.967 mole fraction chloride, 0.870 mole fraction lithium, and 13.8 moles of water per mole of salt, the solid phases being potassium chloride, double salt, and lithium sulphate monohydrate. One congruent invariant point exists, at which the composition of the solution is 1.00 mole fraction chloride, 0.960 mole fraction lithium, and 9.6 moles of water per mole of salt, the solid phases being lithium sulphate monohydrate, lithium chloride monohydrate, and potassium chloride.In the reciprocal salt pair Li2, Na2, Cl2, SO4, and water, at 25 °C there is an incongruent invariant point at which the composition of the solution is 0.873 mole fraction chloride, 0.668 mole fraction lithium, and 15.1 moles water per total mole of salt, the solid phases being sodium chloride, solid solution of sodium and lithium sulphates, and lithium sulphate monohydrate. A congruent invariant point exists, at which the composition of the solution is practically entirely lithium chloride, the solid phases present being lithium chloride monohydrate, lithium sulphate monohydrate, and sodium chloride.
Predominance diagrams of uranium and plutonum species in both lithium chloride–potassium chloride eutectic and calcium chloride
