Project Status: Complete
Project Participants: BHP Billiton, Rio Tinto, University of Queensland, Xstrata, Anglo Platinum, AMIRA
Project Leader: Malcolm Powell (University of Queensland)
The objective of this project was to develop a set of laboratory test procedures to characterise the strength and other relevant physical characteristics of the High Pressure Grinding Roll (HPGR) product – particularly agglomerated flakes. Initially the tests were performed on flake from a small scale HPGR and then on flake from larger machines to determine how flake strength scales up. A range of ores were tested, including ores from existing HPGR installations for comparison.
Laboratory test procedures for characterising HPGR product were critically reviewed and new test procedures were developed for assessing the properties of dustiness, flake competence and cohesion of damp fines. Samples supplied by the project Participants were subjected to the suite of tests and the results have provided a better understanding of material behaviour in HPGRs. The tests indicated that a small quantity of moisture may be beneficial to the operation of HPGRs (reduce operating pressure, increase energy utilisation, reduce dust levels), however these benefits can be lost if the feed is very damp and HPGR throughput may be reduced. Overall the project has helped minimise risk and improved confidence in the design of closed HPGR circuits.