Raw perlite is used as slag coagulant in foundries that their process requests such material (steel, iron, etc). It can be used in molten metal pouring ladles and in continuous induction furnaces.
It forms a lightweight, viscous, cellular mass. This mass attracts all individual slag particles in the metal, coagulates impurities and floats them up to the slag layer. By this way it also prevents retention or re-entry of impurities into the metal bath and virtually eliminates the slag inclusion.
Main advantages of perlite in foundry:
- Coagulates slag and traps impurities
- Simplifies ladle skimming and removal of slag
- Acts as an insulation barrier
- Reaction with melt produces no smoke or fume of health hazards
- Surface effect is mild and not violent.