MANUFACTURING

Malabar Cements manufactures cement through the most modern dry process method based on world-renowned German technology. The major raw materials for cement manufacture are limestone and laterite, which are natural minerals obtained within the state. These raw materials provide all necessary ingredients of cement like lime, silica, alumina and iron oxide. The entire manufacturing process is computer controlled from a central control room and stringent quality control measures are applied at all stages of production.The state of the art pollution control measures like bag filters are also being installed. The process generally involves three stages of production.

Raw Meal

The limestone obtained from captive mines is enriched with higher quality limestone procured from nearby states as and when required. The raw mix normally contains 95% limestone and 5% laterite. The raw materials are crushed to around 20-25 mm size and the proportioned raw materials are ground in a ball mill in dry condition to a very fine powder. The resultant product is called raw meal and is stored in concrete silos where it is pneumatically homogenized to get a uniform product.

Clinker

Clinker is produced in a rotary kiln, which is a cylindrical steel shell of 65m length and diameter 4.2m, lined with refractory bricks.The kiln is inclined at 3% and set rotating at a speed of 2 to 2.2 rpm. It is provided with a 4-stage multi cyclone pre-heater system through which the homogenized raw meal is fed to the kiln inlet by means of belt bucket elevators. The Kiln is fired with pulverized coal and maintained at a temperature of about 14500C. In the pre-heater and kiln, the raw meal undergoes a series of physical as well as chemical changes giving rise to the cement minerals. The resultant product in nodular form obtained from the kiln is called clinker. Clinker is immediately quenched in the clinker cooler to stabilize its properties and stored in the clinker stockpile.

Cement

Cement is produced by grinding clinker with 3 to 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 (OPC). Fly ash / Slag at required proportion is ground along with clinker and gypsum to produce Portland Pozzolana cement (PPC) / Portland slag cement (PSC). The ground cement is stored in concrete silos and packed in 50kg bags using electronic packing machines.