Petroleum coke (PETrolumcoke) is a product formed by separating light and heavy oil from crude oil through distillation, and then converting the heavy oil through thermal cracking. From the appearance, coke is a black block (or particle) with irregular shapes and sizes, with a metallic luster. The particles of coke have a porous structure, and the main element composition is carbon, It accounts for 80 wt% (WT is the abbreviation for Weight, which means weight percent content. 5 WT% is equivalent to 50000 PPM (PPM is in millions) or more, and the rest is hydrogen, oxygen, nitrogen, sulfur, and metal elements.

Petroleum coke belongs to the category of easily graphitized carbon. Compared to metallurgical coke, the microcrystalline structure of petroleum coke has a relatively neat overlap between carbon grid flakes, and the distance between flakes is relatively small; At high temperatures of graphitization, the average grain thickness (Lc) and average width (La) of carbon mesh flakes increase, while the lamellar spacing (d) decreases; The lattice constants (a0 and c0) are close to natural graphite, with a significant decrease in resistivity and a corresponding increase in true density. Therefore, using petroleum coke as raw material can produce graphite electrodes with low resistivity.

Petroleum coke has its unique physical, chemical, and mechanical properties. It is the nonvolatile carbon in the heating portion, volatile matter, and mineral impurities (sulfur, metal compounds, water, ash, etc.) that determine the chemical properties of the coke. Porosity and density in physical properties determine the reactivity and thermophysical properties of coke. Mechanical properties include hardness, wear resistance, strength, and other mechanical properties, particle composition, and other properties affecting processing, transportation, stacking, and storage.