A simple and novel non-linear model of a run-of-mine ore grinding mill circuit, developed for process
control and estimation purposes, is validated. The model makes use of the minimum number of states
and parameters necessary to produce responses that are qualitatively accurate. It consists of separate feeder,
mill, sump and hydrocyclone modules that can be connected to model different circuit configurations.
The model uses five states: rocks, solids, fines, water and steel balls. Rocks are defined as too
large to be discharged from the mill, whereas solids, defined as particles small enough to leave the mill,
consist of out-of-specification coarse ore and in-specification fine ore fractions. The model incorporates a
unique prediction of the rheology of the slurry within the mill. A new hydrocyclone model is also presented.
The model parameters are fitted to an existing plant’s sampling campaign data and a step-wise procedure
is given to fit the model to steady-state data. Simulation test results of the model are compared to
sampling campaign data of the same plant at different steady-state conditions. The model shows promise
in estimating important process variables such as mill power and product particle size and is deemed
suitable for process control studies.