Micro Structure of Clinker

The Cement is manufactured by grinding quality clinker with flyash/Burntclay Pozzolona and gypsum in a open/closed circuit ball mill to a desired fineness (320-350 M2/kg) the alite (C3s) and belite C2s) phases are well developed and uniformly distributed in the clinker. High alite content brings early strength in cement while later strength of cement is achieved by the joint contribution of alite and belite phases. The Tricalcium aluminate phase (C3A) is well maintained in clinker to have sufficient effringite phase with Gypsum and is responsible for one day strength and also keeps the setting time control well units in the limits.

The flyash addition (15-35%) is made according to clinker quality and flyash conforms the requirement of IS 3812-2003. Flyash addition makes the low heat cement and chloride as well as sulphate resistant cement. The leaching effect of lime Ca (OH)2 is also controlled by double action of Flyash and ultimate strength goes on increasing.

• The cement manufacturing process begins when limestone, the basic raw material used to make cement.
• The limestone is combined with clay, ground in a crusher and fed into the additive silos. Sand, iron and bottom ash are then combined with the limestone and clay in a carefully controlled mixture which is ground into a fine powder in roller mill.
• Next, the fine powder is heated as it passes through the Pre-Heater Tower into a large kiln. In the kiln, the powder is heated to 1500 degrees Celsius. This creates a new product, called clinker, which resembles pellets about the size of marbles.
• The clinker is combined with small amounts of gypsum and limestone and finely ground in a finishing mill. The mill is a large revolving cylinder containing steel balls that is driven by a motor. The finished cement is ground so fine that it can pass through a sieve that will hold water.