It works as teeming compound for bottom poured ingots. When added to the meniscus of the liquid steel in the mould produce a molten slag layer with low melting point, covering entire surface of meniscus, to prevent loss of heat & reoxidation of liquid steel.
Forms layers when it comes in contact with liquid steel.
1) Iinfiltrates between mould wall & steel shell for lubrication purpose.
2) Viscous layer: Absorbs non-metallic inclusion by bringing them to the steel- liquid Mincast layer by convection currents & then they are attracted to pass from steel in to the liquid flux layer.
3) Liquidous layer: top of the liquid steel compensating for the loss of powder in the molten slag.