### The influence of mill speed and pulp density on the ...

The balls become coated and the grinding efficiency decreases. The pilot mill is also equipped with a sensor measuring the 'ball and pulp toe and shoulder angles' (see Figure 3). These data are then used to calculate the total pulp and ball charge angle (see Graph 5). Graph 5 clearly illustrates how the ball charge stays quite compact till about 73% solids as the total media angle does not ...