... so they are good construction materials of heat preservation, thermal insulation sound absorption, and corrosion proof, and also industry ... fire mortar, firebrick, and brake linings.3.Heat preservation, thermal insulation and sound absorption materials: underground pipeline, heat preservation ... :Size Bulk specific gravity(Kg/ m2) Water absorption(%) Thermal conductivity (k·m2·h·°C) Impurity(%) 4-8mm ...