Grinding and calcining of gypsum with Pfeiffer grinding plants
gypsum calcining mill is about 24 minutes. This is short in comparison to the time it takes in the gypsum kettle which may range between 60 and 200 minutes. Due to the kettle being heated indirectly the specific thermal energy requirement is about 20 % higher than when the gypsum is calcined directly in the gypsum calcining mill ( Tab 1).