Because of exceptional insulation qualities of perlite it is used in cast refractory.  In the conditions of high temperature refractory is used as insulation layers of higher temperature refractory.

High temperature application
Perlite insulation is used as covering layer of scoops, in coverings mixtures, exothermic and insulation forms, in forming sand and in the production of heat-resistant blocks and bricks.

Hot expulsions and extension
Often perlite interfuses with exothermic powders and used in the hot blowing out and for prevention of shrinkage shells in foundings and bars.