Modelling of the Sala Agitated Mill (SAM) using a simplified solution to
the population balance approach has been carried out. The rate of
breakage is modified by the mill power, providing predictions of the
resulting product size distribution for different grinding conditions and
mill sizes. The power of the mill is estimated by a physically derived
function, using an assumption that the mill power consumption mainly
arises from the ball to ball friction within the mill. The grinding
efficiency, depending on the media ball size and pulp density is
approximated in the model. Experimental work on grinding a complex
sulphide ore using a pilot scale SAM 7.5 has been carried out. Good
agreement has been found between the data from the test campaign and
the simulated values. The model has also been validated with
experimental data from a pilot grinding of calcium carbonate and from an
industrial mill. The model is included in the USIM PAC simulation
software.