Modelling High Pressure Dewatering Rolls for Mineral Tailings

Modelling High Pressure Dewatering Rolls for Mineral Tailings

Nilanka Ekanayakea,b,∗, Sajid Hassana,b, Peter Scalesa,b, Robin Batterhama,b and Anthony Sticklanda,b,∗∗ 

aThe Department of Chemical Engineering, Parkville, Melbourne, 2200, Australia

bARC Centre of Excellence on Eco-Efficient Beneficiation of Minerals (CE200100009), Australia


Keywords: tailing filtration

High Pressure Dewatering Rolls (HPDR) compressional rheology mathematical modelling


High-Pressure Dewatering Rolls (HPDR) is a novel high pressure continuous filtration technology that is being developed for the mining industry to better deal with tailings,concentrates,and backfill. Two permeable rotating rolls in a bath of suspension rotate with vacuum-assisted cake formation to bring the cake to a nip, where a hydraulic force between the twin rolls causes the cake to be compressed and, through rotation, discharged to a hopper. A predictive model is developed to understand the filtration behaviour of compressible suspensions when treated with HPDR. The model in corporates a one-dimensional compressional rheology approach and considers both cake formation and controlled rate compression. Operating parameters, such as the rotational rate of the rolls, slurry concentration, and vacuum pressure,are investigated for their impact on the filtration process. It is found that under specific conditions, such a slow vacuum pressure, low initial solids concentration, and high angular speed, the HPDR may producenon-compressed filter cakes. Additionally, when operating with a fixed gap, there exists a limit to the operability of the HPDR. Solid through put increases with vacuum pressure and initial concentration and angular velocity. However, the final solid concentration reduces with the angular speed. These findings contribute to a better understanding of HPDR behaviour and provide insights for optimizing its performance in practical applications.