... :0.7-0.9g/cc cenosphere fly ash(thermal,heat insulation)microspheres(bulk density 0.7-0.9g/cc) 1. ... -insulatingLower conductivity makes it widely used in producing heat-insulation and sound-insulation materials and Equipments.3) Chemical stabilityChemical features (alumina silicate ... in building material,plastics,ceramic,oil field,beton,well drilling,paint&coating,automobile,air craft etc.