... soluble in fuming sulphuric acid, stable chemical property; can absorb X-ray, and endow the material with high density and surface finish ... soluble in fuming sulphuric acid, stable chemical property; can absorb X-ray, and endow the material with high density and surface finish ... 3,BET Surface: Transforms by the average grain diameter, the unit is the 1g powder relative area.4,325MESH remnant remainder ...