CEMENT PRODUCTION PROCESS AND ENVIRONMENTAL IMPACT OF CEMENT AND CONCRETE.

Cement production is one of the largest industries in the world. Annual world production in 2013 was approximately 4 GT (of which, about half was in China). It is produced in kilns at around 1400oC (2500oF), and approximately 750 kg (1650 lb) of CO2 are released for each tonne (2205 lb.) that is made. This is 400 m3 (524 yd3) of gas; and CO2 normally forms only 0.04% of air. Cement production is responsible for around 7% of worldwide greenhouse gas emissions. The only larger contributors are electricity generation and transport