The application of calcined petroleum coke (CPC) in different industrial fields differs fundamentally in its emphasis on purity, electrical conductivity, reactivity, and physical strength.
Iron and Steel Industry: Focus on Conductivity and Strength, with Stringent Requirements for Sulfur and Ash Content The iron and steel industry primarily uses calcined petroleum coke to manufacture graphite electrodes for electric arc furnace (EAF) steelmaking. In this process, the CPC must withstand extremely high temperatures and severe thermal shock. Therefore, the core requirements are high electrical conductivity and good thermal shock resistance, which are typically achieved through high true density (e.g., >2.08 g/cm³) and low electrical resistivity. Meanwhile, residual sulfur and ash in the electrodes directly affect the quality of the molten steel, so low sulfur (e.g., sulfur <0.5%) and low ash content (e.g., ash <0.5%) are generally required for high-quality CPC. In some cases, needle coke is even required to manufacture high-power electrodes.
Titanium Dioxide Industry: Purity is the Lifeline, with Particularly Strict Control over Heavy Metals The production of titanium dioxide (especially the chloride process) imposes extremely stringent requirements on raw material purity. Here, CPC serves primarily as a reducing agent and heat generator, and its sulfur and heavy metal content directly affects the whiteness and quality of the final titanium dioxide product. Industry standards set very low upper limits for sulfur content (e.g., ≤0.6%), and require strict control over metallic oxide impurities such as vanadium, chromium, manganese, and iron, because even trace amounts can severely impact the product’s color shade. In addition, to suit different chlorination processes, specific particle size requirements are imposed on CPC—for example, fluidized-bed chlorination typically requires a particle size distribution in the range of 74μm–850μm.
Silicon Industry: Equal Emphasis on Impurity Control and Reactivity This sector primarily includes industrial silicon (metallurgical-grade silicon) and photovoltaic-grade polycrystalline silicon. For industrial silicon smelting, CPC serves as a carbonaceous reducing agent, and its ash content and volatile matter affect reaction efficiency and energy consumption—excessively high values increase power consumption. Moreover, the purity of the silicon material directly determines the product grade.
For high-purity polycrystalline silicon used in the photovoltaic industry, the requirements are taken to the extreme. In this case, CPC is not used directly for smelting but rather as graphite hot-zone components inside monocrystalline silicon growth furnaces. Since silicon purity must reach 99.999999999% (11 nines) or higher, the CPC feedstock must have extremely low ash content (e.g., ≤0.3%) and very high true density (≥2.1 g/cm³) to produce high-purity, low-porosity, and oxidation-resistant graphite components, preventing contamination in the high-temperature crystal-pulling environment.
Summary
- Steel requires CPC-based electrodes that conduct electricity well and withstand high temperatures.
- Titanium dioxide demands CPC with extremely high purity, especially minimal sulfur and heavy metals, to ensure the product is white enough.
- In the silicon industry, industrial silicon production emphasizes reactivity and ash content, while photovoltaic-grade polycrystalline silicon requires CPC feedstock of the utmost purity.
Post time: Aug-19-2026