Cement. cement is produced by grinding clinker 3-5% gypsum in a closed circuit ball mill to required fineness. gypsum is added to control the setting properties of cement. grinding clinker and gypsum produces ordinary portland cement.Jiangsu pengfei group co., ltd is the national leading enterprise of building material industry, the manufacturing and exporting base for complete set of cement machinery & equipment, the provincial abide by contracts and keep ones words enterprise. our company can take on the complete set of service such as manufacturing, installation, debugging, etc for the cement machinery, metallurgy.