Major mining companies trial particle sorting technique

ISPS screen deck. Source: CRC CORE

BHP, Norton Gold Fields and Saracen Mineral Holdings are working with the Cooperative Research Centre for Optimising Resource Extraction on a study that could transform the way ore particles are screened and sorted.

The Integrated Screening and Particle Sorting Collaborative (ISPS) Study aims to develop a scientifically rigorous framework for collecting, testing and reporting results for integrated screening and particle sorting techniques in a variety of ore domains.

The study, which began in August 2019, is currently underway at BHP’s Cliffs nickel mine, Norton Gold Fields’ Paddington Gold site and Saracen’s Carosue Dam operation, with all three sites located in Western Australia.

It is expected the study will further expand during its 15-month tenure to include an additional two sites.

The ISPS study program is managed by Laurence Dyer, who is the discipline lead for metallurgical engineering at Curtin University’s Western Australian School of Mines.

The study outcome would be a blueprint for understanding the opportunity for upgrading ore feed including an assessment of operational impacts, economic valuation and implementation approaches, according to Dyer.

“What commonly fails to be taken into consideration is the benefit of first assessing the natural deportment of metal to a size fraction through grade-by-size screening test work, prior to undertaking particle sorting test work,” he said.

“Missing this step has two impacts. Firstly, there is a risk that particle sorting test results will be misinterpreted as being representative of the full sample without considering the mass balance impact of high-grade material that might have been lost in the fine fraction. This fine fraction will not be detected through the particle sorter.

“Secondly, the opportunity may exist to upgrade feed first through determining if there is a concentration of high grade to the fine (or coarse) fraction which can be separated through screening. Undertaking screening in the preparation stage of the particle sorting process will enable analysis and separation of the fine or coarse fractions of a rock mass.”

Dyer said the CRC ORE will benefit from developing a broader understanding of the application and opportunity for applying particle sorting on a range of deposit types and integrating this with natural deportment grade-by-size screening opportunities to maximise value for mining operations.

The ISPS study forms part of the CRC ORE grade engineering program, which is focused on extracting metal more efficiently by separating ore from waste before it enters comminution.

Grade engineering is an integrated approach to coarse rejection that matches a suite of separation technologies to ore specific characteristics and compares the net value of rejecting low value components in current feed streams to existing mine plans as part of a system-view.

The Grade engineering program and the ISPS study would be conducted through CRC ORE’s Kalgoorlie-Boulder Mining innovation hub and Curtin University’s Western Australian School of Mines.

“Particle sorting is an important lever of Grade Engineering,” Dyer said.

“Through this project CRC ORE is looking to develop a better understanding of the value of particle sorting to upgrade mill feed, particularly when combined with grade-by-size screening.”

To keep up to date with Australian Mining, subscribe to our free email newsletters delivered straight to your inbox. Click here.