porous alumina ball ISO9001:2000 Size:3-75mm Material;alumina Porous alumina Ball Product DescriptionHQ- ... -3015-2515-25 Air permeability,m3·cm/m2·h·10Pa0.2-0.81-67-50 Acid resistance,%≥ ... Alkali resistance,%≥85≥85≥80 Thermal shocking resistance,(T)800800800Crushing strength,N/grain100-20000,Deferent upon types ... , but 12 sizes by reference to the diameter, such as Φ3 ,Φ6 ,Φ8 ,Φ10 ,Φ13, Φ16 ,Φ20 ,Φ25 ,Φ ...