### Tubular Ball Mills - ScienceDirect

1.01.2016· A grate discharge mill of dimensions 4.12 m × 3.96 m was loaded to 40% of its volume with gold ore. The mill drew 10.95 kW power per tonne of balls. To grind the ore to the liberation size the mill was run at 72% of the critical speed when charged with balls 64 mm in