6 Finish Milling During the final stage of portland cement ...
6. Finish Milling During the final stage of portland cement production known as finish milling, the clinker is ground with other materials (which impart special characteristics to the finished product) into a fine powder. Up to 5% gypsum and/or natural anhydrite is added to regulate the setting time of the cement. Other chemicals, such as those which regulate flowability or air entrainment ...