Rotary Kiln and Cooler

RCL’s Unit II kiln dimensions are 3.95 meters in diameter and 61 meters in length, with three supporting roller stations. The kiln is lined with high alumina refractory bricks, designed to withstand our kiln process temperature of 1,450° C. A fuel containing 40% pulverised coal is fired into the kiln, with the help of a high momentum multi-channel burner to produce a radiant flame. Because of our high flame radiation, when the raw material reaches the burning zone of the kiln, additives such as alumina and iron ore will melt. This medium of liquid facilitates lime in the kiln to react with silicate to form C₃S, C₂S, C₃A and C₃AF₄.

C₃S and C₂S are known as alite and belite, respectively, and are the main components of our clinker. As the kiln is inclined at 3.5% and rotates at 4.5 RPM, hot clinker drops out of the kiln and into the cooler, where it is quenched by atmospheric air to arrest further chemical reaction. Clinker is then cooled from 1,300° C to 100° C in the cooler. Hot air recovered from the cooler is utilized in the kiln as well as in the calciner as secondary and tertiary air. Cooled clinker is then transported onwards to our clinker storage tank by deep bucket conveyors.