Evolution of Microstructure during Calcination Process and Performance Study of Petroleum Coke

In order to explore the effect of calcination temperature on the microstructure and physicochemical properties of medium and low sulfur petroleum coke, two types of petroleum coke with different sulfur contents were calcined at 600–1400°C. The sulfur content, true density, powder resistivity, Lc value, microstructure and microstructure evolution process of calcined coke were analyzed by DTA-TG-DTG, FT-IR, Raman, polarizing microscope (PLM), FE SEM and other methods. It was found that there is not much difference in the DTA-TG-DTG curves between medium sulfur petroleum coke and low sulfur petroleum coke, and the microstructure evolution process is basically consistent. As the calcination temperature increases, there are significant differences in the growth process and basic properties of carbon crystals in calcined coke, which are closely related to the presence and transformation of sulfur. This study can provide important parameters for the pre-calcined anode desulfurization process in the production of aluminum using medium and low sulfur coke.