Refining agents are tailored to the specific requirements of different metals and alloys. Each metal has unique chemical properties and impurity profiles, necessitating the use of specialized refining agents. Below are some common types of refining agents used in the casting industry:

• Aluminum Refining Agents: Aluminum is prone to hydrogen absorption and oxide formation during melting. Refining agents for aluminum typically contain chlorine, fluorine, or nitrogen compounds, which react with hydrogen and oxides to form gases or slag. These agents are often introduced into the molten metal through inert gas purging or tablet form.

• Copper Refining Agents: Copper refining focuses on removing oxygen, sulfur, and other non-metallic inclusions. Phosphorus-based agents are commonly used for deoxidation, while sulfide-forming agents help remove sulfur. Fluxes containing borax or silica are also used to create a protective slag layer.

• Magnesium Refining Agents: Magnesium is highly reactive and susceptible to oxidation. Refining agents for magnesium often include fluxes containing calcium, barium, or rare earth elements, which stabilize the molten metal and prevent oxidation.

• Iron and Steel Refining Agents: In iron and steel casting, refining agents are used to remove carbon, sulfur, and phosphorus. Lime-based fluxes are commonly employed to form slag, while aluminum or silicon compounds are used for deoxidation.

The selection of refining agents depends on factors such as the composition of the molten metal, the type of impurities, and the casting process. Proper use of these agents ensures the production of high-quality metal with minimal defects.