... graphite, coating ,bauxite (2)High hardness, Low abrasive loss Ceramic beads,It can be used for superfine grinding of relatively soft nonmetal ... flexibility;long useful life(2)Very low abrasive loss(3)High specific weight, true density is 2.7kg/l,bulk density ... is1.75kg/l(4)High performance /price ratio, very reasonable price Alumina grinding ...