Hollow Alumina Sphere Bricks 1,Hollow Alumina Sphere Bricks 2,high temperature resistance 3, low thermal conductivity ... definite proportion as raw material.Characteristic1,high temperature resistance,2,low thermal conductivity,3,good thermal insulation,4, ... Indexes of Hollow Alumina Sphere BricksChemical composition2O3 % ≥2O3 % ≤2 % ≤Bulk densityg/m3≤Compressive strength at normal temperature MPa≥ ...