High pressure grinding rolls – A revolution in high throughput dewatering

Project Leader: Anthony Stickland
Staff: Anthony Stickland, Robin Batterham, Peter Scales
Collaborators: Antoinette Tordesillas (Maths)
Sponsors: Brown Coal Innovation Association
Primary Contact: Anthony Stickland (stad@unimelb.edu.au)
Keywords: deformability; energy efficiency; Minerals – Processing and Materials
Disciplines: Chemical & Biomolecular Engineering
Domains: Convergence of engineering and IT with the life sciences, Optimisation of resources and infrastructure
Research Centre: Particulate Fluids Processing Centre (PFPC)

The way that saturated particulate systems deform and flow in processes such as comminution, extrusion, pelletisation and drying is governed by two important factors, the strength of the particulate network and the water flowrate. The addition of shear during compressional dewatering processes significantly reduces the pressure required to consolidate the material at a given rate or increases the rate at a given applied pressure. The effect is evident in many industrial processes, such as belt press filters, decanting centrifuges and raked thickeners, but the understanding to date has been purely empirical. Understanding the concept of superposed compression and shear allows prediction of technologies that minimise energy losses and maximise impact. A geometry that has the potential for high throughputs and therefore large-scale implementation is high pressure grinding rolls (HPGRs), albeit operated in a novel manner. This project will undertake a parametric study of laboratory-scale rollers in order to show proof of concept. A quantitative model of the HPGR environment will be developed and validated to be used to optimise roller design and processing conditions. The outcomes of this project have great potential for commercial implementation in industries, such as ore comminution, coal upgrading and waste recycling.