... harmful for health. Pingxiang Petrochemical Filteration material of ceramic sand are made of refined pottery clays added with certain modifiers,and ... in surface,porous inside the structure,and have the advantages of high mechanical strength,large specific surface area and porosity. ... Na2O Contant(%)60-6518-217-93-41-43-5Thenical dataItem Index Appearance Rough ball,porous,red&brown Diameter,mm0.5- ...