Carbon Riser

Product Description

Carbon raiser, also known as carbon additive or recarburizer, is a material used in foundry and metallurgical processes to increase the carbon content of molten metal, particularly in steelmaking. It is primarily composed of carbonaceous materials such as petroleum coke, coal tar pitch, anthracite coal, or graphite. Here's an overview of carbon raiser and its role in foundry applications:

1. Composition:

   • Carbonaceous Materials: The main component of carbon raiser is carbon, typically derived from petroleum coke, coal tar pitch, anthracite coal, or graphite. These materials provide the carbon content necessary for adjusting the composition of the molten metal.
   • Volatile Matter: Carbon raiser may contain volatile matter, such as hydrogen, oxygen, and sulfur, which can affect the reactivity and combustion characteristics of the material.
   • Ash Content: Depending on the source of carbonaceous materials, carbon raiser may contain varying amounts of ash, minerals, and impurities. Low ash content is desirable to minimize slag formation and impurities in the molten metal.

2. Function:

   • Carbon Adjustment: Carbon raiser is added to the molten metal to adjust its carbon content to the desired level. Controlling the carbon content is essential for achieving the desired mechanical properties, such as hardness, strength, and ductility, in the final castings.
   • Deoxidation: Carbon raiser helps deoxidize the molten metal by reacting with oxygen and other impurities present in the metal, forming stable oxides that can be removed as slag.
   • Graphitization: In cast iron production, carbon raiser promotes the formation of graphite in the metal matrix, improving its machinability, thermal conductivity, and damping properties.
   • Reducing Agent: Carbon raiser acts as a reducing agent in metallurgical processes, facilitating the removal of oxygen and sulfur from the molten metal and reducing the risk of defects such as porosity and inclusions in the final castings.

3. Types:

   • Graphite: Graphite-based carbon raisers are preferred for their high carbon content, low ash content, and consistent performance. They are particularly suitable for applications requiring high-quality carbon additives.
   • Petroleum Coke: Petroleum coke-based carbon raisers are widely used in steelmaking and foundry applications due to their availability, cost-effectiveness, and acceptable performance characteristics.
   • Coal-Based: Coal-based carbon raisers, such as anthracite coal or metallurgical coal, are also used in certain applications, although they may have higher ash content and lower carbon purity compared to graphite or petroleum coke.

4. Application:

   • Steelmaking: Carbon raiser is added to the molten metal in steelmaking processes, such as electric arc furnaces (EAF) or basic oxygen furnaces (BOF), to adjust the carbon content and improve the quality of the steel.
   • Cast Iron Production: In foundries producing cast iron, carbon raiser is used to enhance the carbon content of the molten metal and promote the formation of graphite, resulting in improved mechanical properties and machinability.
   • Alloy Production: Carbon raiser may be added to alloying processes to modify the composition and properties of metal alloys, such as nodularizing agents in ductile iron production or inoculants in aluminum alloy castings