Explain the classification of petroleum coke in detail
Petroleum coke is a product produced by distillation of crude oil after separating light and heavy oil and then hot cracking of heavy oil. Graphite electrode is one of the main products of petroleum coke and is a high quality material for electric arc furnace steelmaking. Its main characteristics are that the carbon content is usually more than 80wt%, the sulfur content is 0.3wt%-9.0wt%, the rest is hydrogen, oxygen, nitrogen and vanadium, calcium, nickel, sodium and other trace metal elements. It can be divided into sponge coke, pellet coke, quicksand coke and needle coke. China produces mostly sponge coke, accounting for about 95 percent, with the rest being pellet coke and, to a lesser extent, needle coke. Sponge coke is generally used in pre-baked anode, graphite electrode, carburizing agent and other carbon industry, partly used in anode materials, silicon metal, silicon carbide, titanium dioxide and other industries; Projectile coke is generally used in glass, cement, power plant and other fuel fields; Needle coke is mainly used to produce graphite electrode and negative electrode materials. Quicksand coke has a lower calorific value than projectile coke and is also used in fuel industry.