Bond Ball Calcs

BOND BALL TOPSIZE CALCULATION FOR WET OVERFLOW MILLSEnglish case 1 case 2F80, microns 1496 1550SG 3.17 2.57WI, kwh/st 18.50676 14.2% critical speed 77.2 76Mill ID, ft 12.6 19.3

Ball Top Size, inches: 1.3 1.0Ball Top Size, mm 32.5 26.4

MetricF80, microns 1870 1550SG 2.85 2.57WI, kwh/mt 15.66 15.6% critical speed 73 76Mill ID, m 5.88 5.88

Ball Top Size, mm 30.4 26.4Ball Top Size, inches 1.2 1.0

B=[(√FK 3√S gW i

(%C s √3 .281D )]´ 25 . 4

where B = ball dia (mm )

F = F80 (mm) Wi = Work Index ( kWh/t ) Sg = ore specific gravity

Cs = Critical speed

D = Diameter inside shell (m )

K = 350 for wet overflow mills

= 330 for wet grate discharge mills

= 335 for dry grate discharge mills

B=[(√FK 3√S gW i

(%C s √3 .281D )]´ 25 . 4

where B = ball dia (mm )

F = F80 (mm) Wi = Work Index ( kWh/t ) Sg = ore specific gravity

Cs = Critical speed

D = Diameter inside shell (m )

K = 350 for wet overflow mills

= 330 for wet grate discharge mills

= 335 for dry grate discharge mills