... of iron and steel foundries, Lost-foam, Precoated sand;, Sodium silicon sand , Resin sand, Precision casting etc. Advantages:Spherical grain, low thermal expansion, good ... refractory, low density, neutral materials Application:Waterglass bonded sand, resin bonded sand, precision casting, Expendable Pattern Casting (EPC), Copper and Aluminium articles polishingChemical: Al2O3: 70 ...