A flexible and powerful dynamic simulation approach to grinding circuit simulation has recently been developed in CSIRO Minerals. The MATLAB/SIMULINK graphical programming environment has been used to construct a library of dynamic mathematical models of a number of key grinding and separation devices and to link them into various complex dynamic grinding circuits. True real-time dynamic simulation and visualisation of interlinked unit process operations in grinding circuits of arbitrary complexity can readily be achieved. The application of the dynamic simulation approach can help greatly in understanding the sometimes complex, nonlinear behaviour and dynamic interactions in various grinding circuits. Dynamic simulation can be used to test "what-ifs" in grinding process operations such as circuit response to variations in feed and unit operation characteristics. It is a cheap and effective means of investigating circuit optimisation without the risk of possible damage to operating units or production of a large amount of unwanted product during a physical optimisation process. Dynamic simulation is also extremely useful in developing and testing new ideas for process soft-sensors and control. The experience and knowledge gained in dynamic simulation of grinding circuits is directly applicable to other dynamic flowsheet modelling and optimisation problems in the minerals and process engineering industries. The advantages of building flowsheet models within the MATLAB/SIMULINK programming environment include the ability to readily develop and modify continuous, discrete and/or hybrid models of individual unit operations, with solution of the flowsheet system by a powerful in-built suite of equation solvers and analysis of results utilising extensive existing graphical capabilities. Flowsheet models of arbitrary complexity can easily be graphically developed, while individual unit models can be developed in terms of graphical block diagrams and/or customised block models written in computer code. (C) 2004 Elsevier Ltd. All rights reserved.