... carborundum, brown corundum, superfine cement, zirconium sand, and fire-proof materials, etc.(3) High purity materials: quartz, feldspar, α- ... mill production line is equipped with a second classification system, the finished product fineness after second time classification ... ≤2um).3. Adopted highly advanced self-diffluent classification system:(1) The classifiers in ball mill production line have ...