Knowledge of petroleum coke and calcined petroleum coke
1. Petroleum coke
Petroleum coke is a black or dark gray hard solid petroleum product with metallic luster and is porous. Petroleum coke components are hydrocarbons, containing 90-97% carbon, 1.5-8% hydrogen, nitrogen, chlorine, sulfur and heavy metal compounds.
Petroleum coke is a by-product of the pyrolysis of feedstock oil in delayed coking units at high temperatures to produce light oil products. The output of petroleum coke is about 25-30% of the raw oil. Its low calorific value is about 1.5-2 times that of coal, the ash content is not more than 0.5%, the volatile matter is about 11%, and the quality is close to anthracite.
2. The quality standard of petroleum coke
Delayed petroleum coke refers to the green coke produced by the delayed coking unit, also known as ordinary coke, and there is no corresponding national standard at present. At present, domestic production enterprises mainly produce according to the industry standard SH0527-92 formulated by the former Sinopec Corporation. The standard is mainly classified according to the sulfur content of petroleum coke. Among them, the first-grade coke and No. 1 coke are suitable for making ordinary power graphite electrodes in the steelmaking industry, and are also suitable for aluminum carbon in the aluminum making industry; No. 2 coke is used in the aluminum making industry. Electrode paste used in electrolytic cells (furnace) and production of graphite electrodes, No. 3 coke is used for the production of silicon carbide (abrasive material) and calcium carbide (calcium carbide), and other carbon products, also used in the manufacture of anodes for aluminum smelting cells Bottom block and used for blast furnace carbon lining brick or furnace bottom construction.
3. The main use of petroleum coke
The main uses of petroleum coke are pre-baked anodes and anode pastes used in electrolytic aluminum, carbon industry production carbon enhancers, graphite electrodes, smelting industrial silicon, and fuels.
According to the structure and appearance of petroleum coke, petroleum coke products can be divided into 4 types: needle coke, sponge coke, projectile coke and powder coke: (1) Needle coke, with obvious needle-shaped structure and fiber texture, mainly used for steelmaking High-power graphite electrodes and ultra-high-power graphite electrodes in Since needle coke has strict quality index requirements in terms of sulfur content, ash content, volatile matter and true density, there are special requirements for needle coke production technology and raw materials.
(2) Sponge coke, with high chemical reactivity and low impurity content, is mainly used in aluminum smelting industry and carbon industry.
(3) Projectile coke or spherical coke: It is spherical in shape and 0.6-30mm in diameter. It is generally produced from high-sulfur and high-asphaltene residual oil and can only be used as industrial fuels such as power generation and cement.
(4) Powder coke: It is produced by fluidized coking process, with fine particles (0.1-0.4mm in diameter), high volatile content and high thermal expansion coefficient, and cannot be directly used in electrode preparation and carbon industry.
