The Essential Differences Between Graphitized Petroleum Coke and Ordinary Petroleum Coke

1. Atomic Arrangement Structure: A Qualitative Change from Disorder to Order

• Ordinary Petroleum Coke: Carbon atoms are arranged in a disordered or short-range ordered state, similar to the structure of amorphous carbon. It has numerous lattice defects, which limit its electrical conductivity, thermal conductivity, and chemical stability.
• Graphitized Petroleum Coke: After graphitization treatment at a high temperature of approximately 3000°C, carbon atoms are rearranged into a hexagonal layered graphite structure. This structure features high lattice integrity, weak interlayer forces, and low electron migration resistance. This structural transformation endows it with typical graphite properties, such as high electrical conductivity, high thermal conductivity, and excellent chemical stability.

2. Performance Differences: Structure Determines Function

Electrical and Thermal Conductivity

• Graphitized Petroleum Coke: Its resistivity is significantly lower than that of ordinary petroleum coke (can be as low as below 0.001 Ω·m), and its thermal conductivity is several times higher. It is suitable for scenarios with strict requirements on electrical and thermal conductivity (e.g., anode materials for lithium-ion batteries, high-power graphite electrodes).
• Ordinary Petroleum Coke: Due to structural defects, it has poor electrical conductivity and is mostly used in fields with low performance requirements (e.g., fuel, ordinary carbon materials).

Chemical Stability

• Graphitized Petroleum Coke: Its layered structure enhances its resistance to chemical corrosion from acids, alkalis, etc. It is not prone to oxidation and deterioration at high temperatures, resulting in a longer service life.
• Ordinary Petroleum Coke: It is prone to structural damage in high-temperature or corrosive environments, leading to rapid performance degradation.

Impurity Content

• Graphitized Petroleum Coke: The graphitization process can further reduce the content of impurities such as sulfur and nitrogen (sulfur content can be reduced to below 0.1%), minimizing pollution and adverse effects during the smelting process (e.g., pores and cracks in castings).
• Ordinary Petroleum Coke: It has a relatively high impurity content and requires pretreatment (e.g., calcination) to meet the needs of some industrial applications.

3. Application Fields: Performance Differences Drive Demand Differentiation

Graphitized Petroleum Coke

• High-end Metallurgy: As a carburizer, it can efficiently increase the carbon content of molten iron and improve the properties of steel (e.g., strength, toughness), while reducing the introduction of harmful elements such as sulfur and nitrogen.
• New Energy Materials: It is a core raw material for anode materials of lithium-ion batteries. Its high electrical conductivity and layered structure help improve the charge-discharge efficiency and cycle life of batteries.
• Special Carbon Products: Used in the production of large cathode blocks, graphitized electrodes, etc., relying on its high purity, high crystallinity, and high-temperature resistance.

Ordinary Petroleum Coke

• Fuel Field: High-sulfur coke is often used in cement plants, glass factories, power plants, etc., as a low-cost fuel.
• Basic Carbon Materials: Low-sulfur coke, after calcination, can be used in the production of anodes for aluminum electrolysis, ordinary graphite electrodes, etc., but its performance is inferior to that of graphitized products.

4. Production Process: A Trade-off Between Temperature and Cost

• Ordinary Petroleum Coke: Produced through delayed coking or fluid coking processes, with relatively low costs. However, it requires further calcination (at approximately 1300°C) to remove volatile components and moisture, thereby increasing the fixed carbon content.
• Graphitized Petroleum Coke: Using ordinary petroleum coke as raw material, it requires an additional high-temperature graphitization treatment at around 3000°C. This significantly increases energy consumption and equipment costs, but the product has higher added value.

Conclusion: Essential Differences and Selection Logic