Graphite electrode refers to petroleum coke and asphalt coke as the main material, coal tar pitch as binder, which is made by raw material calcination, crushing milling, compounding, kneading, forming, roasting, impregnating, graphitization and mechanical processing. High-temperature graphite conductive material, called artificial graphite electrode, is distinguished from natural graphite electrode prepared by using natural graphite as raw material. There are several types of graphite electrodes used:
(1) Used in electric arc furnace
Electric furnace steelmaking is the largest use of graphite electrodes. The output of China's electric furnace steel accounts for about 18% of the crude steel output, and the graphite electrode for steelmaking accounts for 70% to 80% of the total graphite electrode. Electric furnace steelmaking uses a graphite electrode to introduce a current into the furnace, and smelting is performed by a high-temperature heat source generated by an arc between the electrode end and the charge.
(2) Used in mine electric furnace
The ore electric furnace is mainly used for the production of industrial silicon and yellow phosphorus. It is characterized in that the lower part of the conductive electrode is buried in the charge, an electric arc is formed in the material layer, and the heat generated by the resistance of the charge itself is used to heat the charge, wherein current is required. Graphite electrodes are required for higher density electric furnaces. For example, about 100 kg of graphite electrode is consumed for each 1T of silicon produced, and about 40 kg of graphite electrode is consumed for each 1T of yellow phosphorus produced.
(3) For resistance furnace
The graphitization furnace for producing graphite products, the melting furnace for melting glass, and the electric furnace for producing silicon carbide are all electric resistance furnaces. The materials contained in the furnace are both heating resistors and objects to be heated. Usually, graphite electrodes for electric conduction are embedded in the resistance furnace end. In the furnace wall of the department, the graphite electrode used here is not continuously consumed.
(4) For the preparation of shaped graphite products
The graphite electrode blank is also used to process a variety of shaped graphite products such as enamel, mold, boat and heating element. For example, in the quartz glass industry, for every 1T electrofusion tube produced, a graphite electrode blank 10T is required; for every 1T quartz brick produced, 100 kg of graphite electrode blank is consumed.