Sea Coal (Coal Dust)

1. Form Gas Cushion: To block molten metals in direct contact with the surface of sand mold and prevent burn-on and burn-in from happening. 2. OSer Reducing Atmosphere: To redox oxidized layer of molten metals surface and prevent it from being further oxidized and burn-on defects due to the reaction between castings and sand on the mold surface. 3. Increase the collapsibility of sand mold: To make the mold surface smooth and demolding easier, and to reduce burned sand and penetration defects.