... Alumina Sphere Bricks 1,Hollow Alumina Sphere Bricks 2,high temperature resistance 3, low thermal conductivity ... Characteristic1,high temperature resistance,2,low thermal conductivity,3,good thermal insulation,4,good chemical stability (acid-base erosion resistance ... of Hollow Alumina Sphere BricksChemical composition2O3 % ≥2O3 % ≤2 % ≤Bulk densityg/m3≤Compressive strength at normal temperature MPa ...