{TAIL ~ Preferred grinding media} are spherical ceramic particles having a smooth and substantially uniform exterior surface, {HEAD ~ a high density} and high hardness 
{ TAIL ~ Preferred grinding media } are spherical ceramic particles having a smooth and substantially uniform exterior surface , { HEAD ~ a high density } and high hardness
TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH