Limestone is brought to the factory in 200 mm size pieces. This is reduced to about 60 mm pieces in a Primary Jaw Crusher and then passed into a Secondary Hammer Crusher (Reversible Impactor) to reduce it to below 20 mm pieces and stored in a Storage Yard. Clay, Additive and Coke Breeze are also stored in their respective bays. Generally, thesematerials are procured in below 20 mm size and hence do not require crushing.
However if required they can be passed through the Secondary Crusher before being stored. The Raw Materials viz., Limestore, coke breeze, clay, additives, are then extracted in the correct proportions and are fed into a Ball Mill (Raw Mill) where they are ground to a fineness of 87% passing 170 mesh. The extraction system through Weigh Feeders (high accuracy system) to get a better and high accurate raw mix. The Raw Mill Circuit can either be an Air Swept, Closed Circuit with a Mechanical Classifier or an Open Circuit Mill. Raw Mill with a Mechanical Classifier (Air Seperator) is recommended by us for the following advantages :
The ground raw mix from the raw mill is homogenised pneumatically within the Blending Silos and then stored in a Raw Meal Storage Silo. The raw meal is then elevated to a noduliser hopper (constant head) from where it is extracted in correct quantity with the help of a variable speed Screw Feeder and is fed into a Noduliser.
By wetting the raw meal in noduliser, nodules are formed which then passes into the Vertical Shaft Kiln. Drying, Pre-heating, Sintering and Cooling of clinker takes place in the Vertical Shaft Kiln. Well burnt Clinker is then stored in the open Storage Yard which is allowed to cool naturally for about fifteen days.
Clinker and about 5% Gypsum are ground into fine powder in the Cement Mill which is what we call Ordinary Portland Cement. (OPC). We can offer Cement Mills with either a Closed Circuit or an Open Circuit arrangement. Cement stored in Cement Silo(s) is packed into HDPE bags. Cement bags are stored in the go-down and despatched by truck to the consumer according to demand
