Calcined petroleum coke is used in graphite electrodes for steelmaking or anode pastes (melting electrodes) for aluminum and magnesium. In order to adapt the petroleum coke (green coke) to the requirements, the green coke must be calcined.
The calcination temperature is generally around 1300°C, the purpose is to remove the volatile content of petroleum coke as much as possible.
Petroleum coke is a black or dark gray hard solid petroleum product with metallic luster and porosity. It is a carbon body made of tiny graphite crystals formed into granules, columns or needles.
The petroleum coke component is a hydrocarbon, which contains 90-97% carbon, 1.5-8% hydrogen, and also contains nitrogen, chlorine, sulfur and heavy metal compounds.
Petroleum coke is a by-product when the feedstock oil of the delayed coking unit is cracked at high temperature to produce light oil.
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, ash content is not more than 0.5%, volatile content is about 11%, and its quality is close to anthracite.
The main uses of petroleum coke are pre-baked anodes and anode pastes used in electrolytic aluminum, carbon industry production of recarburizers, graphite electrodes, smelting industrial silicon and fuels.
Calcined petroleum coke is used in graphite electrodes for steelmaking or anode pastes (melting electrodes) for aluminum and magnesium. In order to adapt the petroleum coke (green coke) to the requirements, the green coke must be calcined. The calcination temperature is generally around 1300°C, the purpose is to remove the volatile content of petroleum coke as much as possible. This can reduce the hydrogen content of petroleum coke re-products, increase the degree of graphitization of petroleum coke, thereby improve the high temperature strength and heat resistance of the graphite electrode, and improve the conductivity of the graphite electrode.
Calcined coke is mainly used in the production of graphite electrodes, carbon paste products, diamond sand, food-grade phosphorus industry, metallurgical industry and calcium carbide, among which graphite electrodes are the most widely used.
The raw coke can be directly used for calcium carbide as the main material of calcium carbide without calcining, to produce silicon carbide and boron carbide as abrasive materials. It can also be directly used as coke for metallurgical industry blast furnace or blast furnace wall lining carbon brick, and it can also be used as dense coke for casting process.