Are there Differences in Size Distribution when Comparing Conventional Crushing and HPGR?

G Lane, C Morley, D Yataco and I Ritchie

MetPlant 2017 – Metallurgical Plant Design and Operating Strategies – World’s Best Practice, 11-12 Sep 2017, Perth, Australia

Abstract

Marcobre SAC (Marcobre) is developing the Mina Justa project in Peru. The project has a lower grade oxide orebody overlaying the higher grade sulfide orebody. The oxide ore is treated by acid leaching; consumption of acid is high and is managed by vat leaching rather than the more conventional heap leaching process.

The leaching process uses ore crushed to 100% passing 8 mm to optimise copper recovery. Acid consumption generally increases with a higher proportion of fines. Marcobre is investigating a three-stage crushing circuit with high pressure grinding rolls (HPGR) in the third stage, instead of the more conventional four-stage cone crushing circuit.

The use of HPGR can result in higher fines production due to the higher compression forces in the crushing zone. This paper reports on the outcomes of the test work completed by Marcobre in 2016 and 2017 to manage fines production and compare the use of HPGR with conventional crushing on a high acid consuming ore.

At moderate pressing forces, a HPGR crushing circuit appeared to produce similar size distributions to cone crushing. On average, both the copper recovery and the acid consumption in subsequent vat leaching were higher with HPGR crushing than with cone crushing.

AUTHOR DETAILS

G Lane (1), C Morley (2), D Yataco (3) and I Ritchie (4)

(1) – FAusIMM, Chief Technical Officer, Ausenco. Email: This email address is being protected from spambots. You need JavaScript enabled to view it.

(2) – Principal Process Consultant, Ausenco. Email: This email address is being protected from spambots. You need JavaScript enabled to view it.

(3) – Process Manager, Marcobre SAC. Email: This email address is being protected from spambots. You need JavaScript enabled to view it.

(4) – MAusIMM, Consulting Metallurgist, Marcobre SAC. Email: This email address is being protected from spambots. You need JavaScript enabled to view it.

Please contact the authors for further details of this paper.

ACKNOWLEDGEMENTS

CEEC acknowledges and thanks the Australasian Institute of Mining and Metallurgy and MetPlant convenors and organising committee for organising the MetPlant 2017 Conference.

Abstracts can be found at the AusIMM MetPlant conference website (http://www.metplant.ausimm.com.au/abstract_list)

Full papers published in the Conference Proceedings can be purchased from the AusIMM website http://www.ausimm.com.au/productcatalog/search.aspx .