... 10 ys experience manufacter 5.quick reply Introduction: 20%-80% Alumina Content Porous Ceramic Balls also called filtering balls ... asphaltine, heavy metals and iron ions of less than 25μm. If the porous ball is set on the ... 12 grades by reference to Al2O3 content varied from 25% to 80%, and every more 5% constitutes a grade, ... such as Φ3,Φ6,Φ8,Φ10,Φ13,Φ16,Φ20,Φ25,Φ30,Φ38,Φ50 and Φ75. The products in ...