The Evolution of Medium Sulfur Petroleum Coke during Heat Treatment and Coking Property

Calcined petroleum coke serves as the principal raw material for pre-baked aluminum anodes. This study explores the influence of different calcination temperatures on the performance of petroleum coke, and explores the factors affecting coking property of petroleum coke blended with different proportions of calcined coke. This study analyzes the basic properties of medium sulfur coke from three different origins and evaluates the performance of petroleum coke: moisture, volatile matter, ash content, sulfur content, true density, powder resistivity, and coke ratio. The Lc value, microstructure evolution, and coking property were analyzed through DTA-TG-DTG, FTIR, Raman, XRD, polarizing microscope, and other tests. The research results indicate that the pyrolysis of three petroleum coke exhibits three stages of weight loss. As the calcination temperature increases, the carbon crystal structure is transformed to orderization, the crystal structure becomes more complete, and the microstructure evolves from short fibers to long fibers. The sulfur content decreased, the powder resistivity and true density both change towards better performance. As the blending ratio of calcined coke increases, the coke ratio of petroleum coke decreases and overall transitions towards orderization. FTIR detection shows that the asphaltene in petroleum coke significantly impacts the coking property.