Vaporization study of sodium sulphate — potassium sulphate binary system by Knudsen effusion mass spectrometry

The vaporization of samples of different chemical and phase compositions in the Na2SO4-K2SO4 system was investigated over the temperature range 1100 K–1400 K by the use of Knudsen effusion mass spectrometry. The gaseous species Na(g), Na2SO4(g), K(g), K2SO4(g), SO2(g), O2(g) and NaKSO4(g) were identified in the vapour over the samples investigated. The thermodynamic activities of sulphates in the examined system at 1350 K were obtained, which allowed calculating the chemical composition of the vapours present in the high temperature zone of cement kilns.