Slag-coagulants are specially manufactured and graded siliceous volcanic rock with rhyolitic mineral as its main component. At molten metal temperatures the Perlite granules expand and form a low density, high volume crust which mops up the slag, which can be lifted off the metal with ease leaving behind a clean surface.
Properties of Union Perlite Foundry Additive:
High Temperature Insulation
Specially graded expanded Perlite can be used as an insulating cover on the surface of molten metal to prevent excessive heat loss during delays in pouring. Expanded Perlite can be used with exothermic powders often mixed 3 – 20% by weight to prevent shrinkage cavities in ingots and castings.