In the graphite electrode for steel making or anode paste for aluminum and magnesium making (melting electrode), in order to make petroleum coke (coke) meet the requirements, the coke is calcined. Calcination temperature, petroleum coke volatiles are considered factors.

　　(1) Remove moisture and volatile content from raw materials

The volatile content of raw materials can be eliminated by calcination, thus increasing the fixed carbon content of raw materials. The water in raw materials is eliminated by calcination, which is conducive to crushing, screening and grinding operations, improve the adsorption performance of carbon raw materials to the binder, and improve the quality of products.

(2) Improve the density and mechanical strength of raw materials

After being calcined, the carbon material shrinks in volume, increases in density and strength due to the elimination of volatiles, and obtains better thermal stability, thus reducing the secondary shrinkage of products during calcination.

　　(3) Improve the conductivity of raw materials

After calcination, volatiles are removed, and the molecular structure also changes, reducing the electrical resistivity and improving the electrical conductivity of raw materials. Generally speaking, the higher the degree of calcination, the better the conductivity of calcined material.

(4) Improve the oxidation resistance of raw materials

After calcination, as the temperature of carbon raw materials rises, impurities such as hydrogen, oxygen and sulfur will be discharged successively through pyrolysis and polymerization process, and the chemical activity will decrease and the physical and chemical properties will become stable, thus improving the oxidation resistance of raw materials.

Calcined char is mainly used in the production of graphite electrode, carbon paste products, carborundum, food grade phosphorus industry, metallurgical industry and calcium carbide, among which the graphite electrode is the most widely used. And coke without forging burning can also be directly used for calcium carbide as the main material, the production of silicon carbide and boron carbide as grinding materials, but also for casting process with dense coke and other aspects.