Cement Manufacturing Process

Riddhi Siddhi, a cement manufacturing  plant believes in fineness of cement, measured by Particle Size Analyzer to optimize the particle size distribution for better quality product.

From mine to cement

Basic raw materials required to manufacture cement is Limestone (90 - 95%), Clay/Marl, Shale, Bauxite, Iron Ore/Laterite/Mill Scale. 

The Limestone from Mines is brought to the Crusher through dumpers where the size reduction takes place to the extent of 70 - 90 mm max; transported through belt conveyor. Online Cross Belt Analyzer is provided to understand the quality of Limestone being fed and stacked thru stacker, longitudinal/Linear manner to minimize the deviations when extracted to make raw mix. 

Depending on the purity of the limestone the additives/corrective materials are chosen and stacked in defined areas.

The materials are re-claimed through the machine called re-claimer and dumped in respective raw mill hoppers, then the material is proportionately mixed with the help of QCX - Blend Expert of weigh feeders, transported to "Vertical Raw Mill" through collecting belt conveyor where fine grinding takes place.


The finely ground material's sample is transported to the laboratory through Tube Post/Pneumatic system periodically where "ROBORT" takes care of preparation part and analyzed by XRF & XRD. The entire laboratory control activities are taken care by Robo-Lab before storage the material in silo where continuous homogenization is done then transported to Pre-heater thru bucket elevator. The finely ground raw meal is called Kiln feed when completely homogenized and extracted, the material passes thru different temperature (from 250-1050 Degree Celsius) and pressure before reaching the Kiln inlet, at this stage 90 - 95% of the material is calcined. 

Similarly, the solid fuel is also pulverized to the required fineness in a Vertical Coal Mill which is required to heat up the material in two stages (Pre-heater & Kiln). The pre-heater consisting of six stages.

Pre-heated material / calcined material which enters in Rotary kiln and pass thru higher temperatures where Clinker phases are formed at 1300 – 1400 Degree Celsius. The clinker temperature is brought down from 14000; to 100 +/- 20 by rapid cooling with the help of Crossbar cooler to stabilize the phases of clinker when it passes through cooler then the clinker is stored in a storage silo.

The Clinker stored in designated place / silo and Gypsum from other end is extracted and dropped in designated Cement mill hoppers. The material is fed to the cement mill with proportion of 95% & 5% (Clinker & Gypsum) and ground to the required fineness in Vertical Cement Mill to produce OPC cement. The fineness is measured by Particle size Analyzer to optimize the particle size distribution for better quality product.