石油通过真空残渣a coking unit and cracked at 500-550 ° C to produce black solid coke. Its appearance is a black or dark gray honeycomb structure, and the pores in the focal block are mostly elliptical and penetrate each other.
It is generally considered to be an amorphous carbon body; or a highly aromatic polymer carbide containing a needle-like or granular structure containing minute graphite crystals. The hydrocarbon ratio is very high, ranging from 18 to 24. The relative density is 0.9 to 1.1, the ash content is 0.1% to 1.2%, and the volatile matter is 3% to 16%.