... size:3-70mm, 20-70 with same price, Alumina pebbles, used in ceramic tile, cement, chemical, mineral 95% :Advantages:The products ... the ball will not pollute the grinded materials, so it can keep the purity and improve the stability of grinded materials ... grindingCharacters save the grinding time, enlarge the smashing room. SoIt can improve the grinding efficiency. Index for alumina grinding balls: ...