The influence of water vapour on the transformation of γ calcium sulphate anhydrite to β anhydrite

✍ Scribed by J.J. Gardet; B. Guilhot; M. Soustelle

• Publisher: Elsevier Science
• Year: 1976
• Tongue: English
• Weight: 273 KB
• Volume: 6
• Category: Article
• ISSN: 0008-8846
• DOI: 10.1016/0008-8846(76)90117-4

✦ Synopsis

The isothermal kinetics of the transformation of y calcium sulphate anhydrite to B anhydrite have been determined. All the curves obtained have a sigmoidal form. We have also observed an influence of the water vapour pressure on the rate of formation of B anhydrite. On each plot of rate vs. water vapour pressure one observes a maximum whose position shifts to lower values of water vapour pressure when the temperature decreases. The formation of B anhydrite a low temperatures may be explained by the geometry of the water vapour pressuretemperature diagram of the hydrated forms of calcium sulphate, and by the "mineralizing" action of water vapour at or close to saturation.