1. Under the same conditions, the graphite electrode made of oil-based needle coke is easier to form than coal-based needle coke in terms of performance.
2. After making graphite products, the density and strength of graphitized products of oil-based needle coke are slightly higher than those of coal-based needle coke, which is caused by the expansion of coal-based needle coke during graphitization.
3. In the specific use of graphite electrodes, the thermal expansion coefficient of graphitized products of oil-based needle coke is relatively low.
4. In terms of physical and chemical indicators of graphite electrodes, the specific resistance of graphitized products of oil-based needle coke is slightly higher than that of coal-based needle coke products.
5. The most important thing is that coal-based needle coke will expand when the temperature reaches 1500-2000°C during the high-temperature graphitization process, so the temperature rise rate must be strictly controlled, and the temperature cannot be raised rapidly. It is best not to use the serial graphitization process In production, the expansion of coal-based needle coke can be controlled by adding additives, and the expansion rate can be reduced, but it is difficult to achieve that of oil-based needle coke.
6. Calcined oil-based needle coke has a large content of small coke particles and a fine particle size, while coal-based needle coke has a small content and a large particle size (35-40 mm) can meet the particle size requirements of the formula, but it brings difficulties to users. .
7. According to the introduction of Japan Petroleum Coke Company, it is believed that the composition of oil-based needle coke is simpler than that of coal-based needle coke, so it is easy to control during coking and processing. From the above, oil-based needle coke has four disadvantages: low false specific gravity , low strength, low CTE, and low specific resistance, the first two lows are not good for graphite products, and the latter two lows are beneficial to graphite products.
Post time: Feb-13-2023
