Portland Cement is defined as “Hydraulic Cement (cement that not only hardens by reacting with water but also forms a water resistant product) produced by pulverizing clinkers consisting essentially of hydraulic calcium silicates, usually containing one or more of the forms of calcium sulfate as in inter ground addition”
 
Clinkers are nodules (diameters, 0.2-1.0 inch of a sintered material that is produced when a raw mixture of predetermined composition is heated to high temperature.  The low cost and widespread availability of the limestone, shales and other naturally occurring materials make Portland cement one of the lowest-cost materials widely used over the last century throughout the world.

Cement Plant Systems

The cement plant will produce clinker, which is suitable for manufacturing of Ordinary Portland Cement (OPC), Sulphate Resistant Cement and Slag cement, with a production capacity of 5000 TPD.  The process is based on modern dry process technology of cement manufacture.

The Cement Manufacturing Process

The word “cement” is based on the Latin word “caementum” .The binder that is used in the production of concrete and mortar has the ability to harden even in water. Different applications require the use of various types of cement with a specific composition. The properties can also be varied through addition of different additives.

Crushing 

The limestone produced in the mines is transported to crusher site with the help of dumpers and tippers. The crushed limestone is transported to Stacker/ Reclaimer with the help of Belt conveyor.  The crushed limestone travelling on the belt conveyors is stacked in layers with the help of stacker machine, which moves to and fro along the side of stacking yard. The stacked materials is then cut in slices with the help of a reclaiming machine which mixes the layers of stacked limestone which reduces the variation in quality of limestone as compared to the large variations obtained in the limestone obtained from mines.

Raw Material Grinding and Burning

The pre-blended limestone from stack pile is transported to raw mill hoppers. More than one hoppers are used for proportioning of raw mix. Raw mill hoppers are provided with continuous weighing machines known as weigh feeders in order to produce a suitable raw meal proportioned appropriately for production of desired good quality of cement clinker. The raw materials are finely grinded in a vertical roller mill in order to produce the raw mix.

Pyro processing

The raw mix is preheated before it goes into rotary Kiln, which is heated by a flame that can be approximately by 1500 deg C. The raw mix burns at this temperature producing clinker which when it leaves the kiln. This is rapidly cooled with air fans. The raw mix is burnt to clinker which is the basic material for making cement.

Grinding, Storage, Packing, Despatch

The clinker and the gypsum are very finely ground in a vertical roller mill giving a pure cement. Other secondary additive materials can also be added to make a blended cement. The pulverized cements are stored in storage silos.

Depending upon the market requirements the cement is loaded in bulk or packed in bags with the help of electronic rotary packers, loaded on to trucks and finally despatched to the required destinations.