Model predictive control of a coal dense medium drum separator

Abstract: Coal processing is typically performed by making use of gravity separation. A technology used to process larger sized coal particles (typically above 25mm) is a dense medium drum (DMD) separator. These plants make use of a medium set at a specific density to separate coal from gangue. This paper shows how nonlinear model predictive control (NMPC) can be applied to an industrial DMD plant with a process objective to both increase yield while minimising ash content (i.e. improving grade). The results are significant as the DMD yield improved by 7.5% while ash content improved by 1.5%. The dynamic model of a DMD separator developed in a previous publication by the authors was used in the NMPC simulations.