porous alumina ball ISO9001:2000 Size:3-75mm Material;alumina Porous alumina Ball Product DescriptionHQ-MH Porous ceramic balls is also called filtering balls. It is made by make 20-30% pores inside the inert ceramic balls. Therefore it can be used not only for supporting and covering the catalyst, but also for filtering and eliminating the impurities of grain, gelatin, asphalting, heavy metal ...