Aluminum and aluminum alloys are easily inhaled and oxidized during smelting, so they must be sprinkled with thermal insulation covering agents for protection. Its main components are chloride and fluoride salts, and there are other salts and compounds. All components have undergone proper heat treatment to remove adsorbed water and crystal water, and undergo sieving treatment to ensure uniform particle size. The surface of molten aluminum has low viscosity and good flow performance. After spreading the covering agent, it can ensure that a thin liquid protective film is formed on the surface of molten aluminum in a very short time.

The thermal insulation covering agent can form a dense protective layer, reduce the involvement of gas, and reduce the metal loss caused by the oxidation of the liquid surface. It has the advantages of moderate melting point, good fluidity, good large cap, less dosage, low cost, and very low metal content in the formed slag