【Needle Coke】Application in Graphite Electrodes

Graphite electrodes are primarily used in electric arc furnaces for steelmaking, ore-smelting furnaces, and resistance furnaces. In recent years, due to the environmental benefits of electric arc furnace steelmaking compared to blast furnace steelmaking, many countries have been favoring the electric arc furnace steelmaking industry in their policies. The expanding scale of electric arc furnace steelmaking has driven the demand for graphite electrodes. In 2021, the proportion of electric arc furnace steelmaking in China's crude steel production rose to 15%, a 5% increase from 2020. 

It can be predicted that with the background of carbon neutrality, the proportion of electric arc furnace steelmaking may accelerate. In China, 70% to 80% of the total consumption of graphite electrodes is used for electric arc furnace steelmaking. Graphite electrodes are classified into RP, HP, and UHP graphite electrodes. In terms of composition, the aggregate of RP graphite electrodes is petroleum coke. In HP electrodes, petroleum coke and needle coke account for 70% and 30%, respectively. Needle coke constitutes 100% of the aggregate in UHP electrodes.

Currently, electric arc furnace steelmaking is continuously evolving towards larger scale and higher power. Consequently, the requirements for graphite electrodes in electric arc furnace steelmaking are becoming increasingly stringent. Considering that the maximum allowable current for electric arc furnace electrodes is positively correlated with the diameter of the graphite electrodes, the development of large-diameter graphite electrodes is imperative. The production of large-diameter graphite electrodes requires high-quality needle coke.

Furthermore, needle coke can also be used to produce electrode nipples. Typically, the quality standards for electrode nipples are higher than those for graphite electrodes. This is mainly because electrode nipples have smaller diameters and undergo greater stress during use, requiring them to have higher flexural strength. Table 1 shows the standards for UHP electrodes and electrode nipples in China, indicating that as the diameter of the electrodes increases, the technical parameter requirements also increase. Feel free to communicate with us regarding carbon product technologies at any time.