... the impurities fail to be eliminated in former process could be adsorbed in the pores inside the balls, ... cycle of the system. As the impurities present in the materials are different, the user can select ... % to 95%,and every more 5% constitutes a grade, but 12 sizes by reference to the diameter, ... ,Φ25 ,Φ30 ,Φ38 ,Φ50, Φ75. The products in other grade and sizes can be designed and manufactured if to the ...