The binary system K2SO4CaSO4
The binary system K 2 SO 4 CaSO 4 was studied by means of heating-cooling curves, differential thermal analysis, high-temperature quenching technique and by means of a heating stage mounted on an X-ray diffractometer. Compositions and quench products were identified optically and by X-ray. Limited solid solution of CaSO 4 in K 2 SO 4 was found. There is a eutectic at 875°C and 34 wt. per cent CaSO 4 . Calcium langbeinite melts incongruently at 1011°C. The melting-point of CaSO 4 (1462°C) was determined by the quenching technique using sealed platinum tubes. The only intermediate crystalline phase found in the system is K 2 SO 4 ·2CaSO 4 (calcium langbeinite).
Journal of Inorganic and Nuclear Chemistry↗