The process of high-temperature (1200-1500 ° C) heat treatment of carbonaceous raw materials under isolated air conditions is called calcination. Calcination is the first heat treatment process in carbon production, which causes a series of changes in the structure and physical and chemical properties of various carbonaceous materials.

Anthracite and petroleum coke both contain a certain amount of volatile matter and require calcination. The coking temperature of asphalt coke and metallurgical coke is relatively high (above 1000 ° C), which is equivalent to the temperature of a calcination furnace in a carbon plant. It can no longer be calcined and only needs to be dried with moisture. But if asphalt coke and petroleum coke are mixed before calcination, they should be sent to the calcination furnace together with petroleum coke for calcination. Natural graphite and carbon black do not require calcination.