High alumina ball means alumina ball with aluminium oxide content higher than 90%, high alumina ball is high efficiency grinding media in today industry. The high alumina ball works together with the high alumina mill linings brick will benefits you: > Less grinding time, doubled productivity. > Less wear loss of the ball and linings, more clean you final product keep. > Longer service life, less down time Physical Properties: 1) Bulk Density : 60mm > 3.65, 50mm > 3.65, 40mm > 3.65, 30mm > 3.65, 20mm > 3.63 2) Self Wearloss (24h) : < 0.04 3) Water absorption : < 0.1% 4) Hardness (M0hs) : 9 5) Service Temp : > 1600 C 6) Color : White