Cement Manufacturing Process Explained

Seamless blending of superior quality raw materials

Correct blending and concentrating on the quality of raw materials are the two key factors that decide the superiority of the cement. Raw material blending is in fact one of the most important processes in cement manufacturing since it has a direct impact on cement quality.

One of the fundamentals of cement manufacturing is to ensure the right chemical composition of the cement raw mill. A raw mill with a superior fineness and well-controlled chemical composition using as advanced control system can improve the cement quality and define critical cement craft parameters. Amrit Cement uses the best of raw materials and has an enviable infrastructure supported by advanced technologies to ensure supreme cement quality. Physical and chemical analysis of clinker cement and fly ash with Bureau of Indian Standard Specifications by experts from India and Overseas ensures excellence in its product offerings.

Pre-Blending and Raw mill Stage

Limestone from mines are brought to plant site and stored in the yard then fed to dump hopper of primary crusher by mixing high-grade and low-grade limestone in defined proportion to meet the quality norms. The primary crusher is designed with 350 TPH and secondary crusher is installed to reduce the limestone size to further meet the process requirement before reaching the longitudinal stock piles. Longitudinal stacking method is also termed as “Chevron Method” to improve the consistency while re-claiming. The stacker and re-claimer are designed for stocking and extraction of limestone and other corrective materials are fed in to respective hopper. Underneath the hoppers weight feeders are installed to make the proportions of desired mixing ratio. The main raw materials required for manufacturing clinker and cement are Limestone, Clay and Laterite. All the raw materials are stored in respective hoppers and underneath the weight feeders are installed to make the mix proportion.

90 – 95% of Limestone, 2 – 5% of Clay and 3 – 5% Laterite

The above mix proportion is ground in Raw mill at 110 – 118TPH (Ball mill) to achieve desired fineness and fed into CF silo (continuous Flow silo – concreted, capacity 4500MTs) where extraction and filling takes place simultaneously. This kind of system is well-proven for uniform feed to kiln to avoid the variation in burning system.

Soiled Fuel

Coal is used for burning the raw mill. The coal received from various vendors is stacked at the designated coal shed and quality is checked by collecting the samples manually. The coal is then proportionately mixed if required to get uniform desired quality. This coal is then fed into dump hopper to feed in the ball mill where it is pulverized to desired fineness at 12 – 13 TPH and stored in fine coal bins for PC and Kiln firing.