hp high density graphite electrode
Needle coke and hp high density graphite electrode
The production process of carbon materials is a strictly controlled system engineering. The production of hp high density graphite electrode, special carbon materials, aluminum carbon, and new high-end carbon materials cannot be separated from the combination of raw materials, equipment, technology and management four major production factors and related proprietary technologies.
Raw materials are the key factor that determines the basic characteristics of carbon materials, and the properties of raw materials determine the performance of carbon materials. In the production of ultra-high pressure and high-pressure hp high density graphite electrode, high-quality needle coke is the first choice, and high-quality bonding pitch and impregnated pitch are also required. But only high-quality raw materials, lack of equipment, technology, management elements and related technical know-how, can not produce high-quality UHP and HPhp high density graphite electrode.
Based on the characteristics of high-quality needle coke, this article expounds some personal opinions for discussion by needle coke manufacturers, electrode manufacturers, and research institutes.
Although the industrial production of needle coke in my country lags behind foreign companies, it has developed rapidly in recent years. At present, it has begun to take shape. From the perspective of total output, it can basically meet the needs of domestic carbon companies for the production of ultra-high pressure and high-pressure hp high density graphite electrodes for needle coke. However, the quality of needle coke still lags behind that of foreign companies. The fluctuation of batch performance has affected the demand for high-quality needle coke in the production of large ultra-high pressure hp high density graphite electrode, especially the high-quality needle coke used in the production of hp high density graphite electrode joints.
High-quality petroleum needle coke is the main raw material for the production of large ultra-high pressure hp high density graphite electrode by foreign carbon companies. Japanese carbon companies also use some coal needle coke as raw materials, but they are only used to produce hp high density graphite electrodes with specifications less than Φ600 mm. At present, coal-based needle coke is the main variety of needle coke in my country. Carbon companies produce high-quality, large-scale ultra-high pressure hp high density graphite electrode, and often rely on imported petroleum series needle coke, especially the production of high-quality joints, which are imported from Japan’s Mizushima Petroleum series needle coke and British HSP petroleum. Series of needle coke is used as raw material.
At present, the ash content, true density, sulfur content, nitrogen content, particle size distribution, thermal expansion coefficient and other conventional performance indicators of needle coke produced by various enterprises have been compared with the industrial performance indicators of foreign needle coke. However, compared with foreign countries, needle coke still lacks classification methods with different properties. Therefore, the produced needle coke is generally called “tube product”, which cannot reflect different grades of high-quality and high-priced needle coke.
In the performance and energy comparison of needle coke, in addition to the conventional performance comparison, carbon companies should also pay attention to needle coke CTE classification, particle strength, anisotropy, uninhibited state and expansion data in inhibited state, etc., and needle coke The characteristics of the coke in the expansion and contraction temperature range. Since these thermal properties of needle coke are very important for the control of the graphitization process during the production of hp high density graphite electrode, the influence of binders and impregnants on the thermal properties of pitch coke after roasting is not ruled out.