26/10/2021 · Example of steel grinding ball proportioning A beneficiation plant in Singapore loads balls into a ϕ 1500mm×3000mm wet grid type ball mill, determines the filling rate ϕ = 50%, and selects cast steel grinding balls δ = t/m 3. The ball mill processes the mediumhard ore. 1. See Table 1 for the sieving analysis results of all the ore ...