Quiz : Look at the following flowchart and narrate the process of
manufacturing of cement in about 100 words :
The raw materials used for making cement are clay and limestone. Limestone is brought from quarries. Clay is mined from plains. Then limestone is crushed in stone crusher. It is made into a fine powder. Then it is mixed with dry clay. There is a special device called as blending silos for this purpose. Then, the limestone and clay mix is fed into a kiln. The kiln is rotated well. The mixture is then heated to a very high temperature of 1500o. C. As a result, clinkers are formed. These clinkers are ball-shaped. They are very hard. These clinkers are crushed and finely ground into a powder. Cement is obtained. This cement is mixed with 5 % gypsum. This decreases the setting time of cement. This is called Portland cement.