Solid–liquid phase equilibria in the system K2SO4–MnSO4–H2O at 298 K and 313 K

Phase equilibria studies of the system K2SO4–MnSO4–H2O published revealed discrepancies between the data presented in the literature regarding the solid phases formed at ambient temperatures. The solubility in the system at 298 K and 313 K was determined. At 298 K, the existence of the double salt K2SO4·3MnSO4·5H2O and of MnSO4·H2O was confirmed. The examinations at 313 K showed the formation of the stable solid phases MnSO4·H2O, K2SO4·2MnSO4, K2SO4·MnSO4·1.5H2O, K2SO4 and the formation of a metastable phase K2SO4·MnSO4·2H2O.