Carbon Additives - Graphite Products and Their Applications

2025-11-07 16:09:06

To ensure the quality of steel products meets standards during steelmaking, the carbon content in the molten steel must be adjusted.‌ ‌Carbon additives are introduced into the molten bath to increase carbon levels, primarily used in electric arc furnace (EAF) steelmaking.‌

‌During the steelmaking process, impurities such as sulfur (S), phosphorus (P), silicon (Si), and others are removed through slag formation.‌ ‌Simultaneously, decarburization occurs.‌ ‌Therefore, carbon addition is necessary during the final composition adjustment stage, following the melting and refining period.

‌As carbonaceous materials for increasing carbon content, particularly carbon additives, some are produced in briquette form. However, powdered graphite or artificial Graphite electrode processing scraps are more commonly used.‌

‌Spherical carbon additives offer the advantages of dust-free feeding into molten steel, higher yield, and ease of handling.‌

‌Furthermore, to facilitate penetration through the slag layer and absorption by the molten steel, carbon additive briquettes are often compacted into forms containing 20% to 50% iron mixed with the carbonaceous component.

Electrode processing scraps exhibit high carbon content and are readily assimilated by molten steel, making them excellent carbon additives. Powdered graphite or coke breeze are also extensively used as carbon additives. Their particle size and purity vary depending on the application requirements. However, carbon additives used in the later stages of refining demand high purity, with particular emphasis on minimizing impurities like sulfur (S) and phosphorus (P). Sulfur content is preferably kept below 0.2%.