MOUNT CARLTON COMMINUTION CIRCUIT DESIGN, START-UP AND OPTIMISATION

B PUTLAND, I LOVATT, A CERVELLIN AND D SCHWANN

14^thAusIMM Mill Operators’ Conference, 29-31 August 2018, Brisbane, Australia

Australia

The Mount Carlton project in Queensland's North East sits on a high-sulphidation epithermal style deposit

rich in gold, copper and silver.

Mt Carlton is an open pit mining operation with ore processed using a primary crusher, single stage SAG mill

and flotation to produce a concentrate for sale. Orway Mineral Consultants (OMC) was involved in the

original design of the comminution circuit and the project was commissioned in late 2012, with first

concentrate shipped in March 2013. When Evolution sought to optimise the project in 2015, OMC was

invited to assist by undertaking a circuit review to identify opportunities for the optimisation.

During 2016, the Mt Carlton site team implemented the optimisation strategies developed in conjunction with

OMC. These included reconfiguring the SAG mill discharge arrangement, reducing the average ball diameter

and allowing the mill to operate at higher speed and under more autogenous conditions. Cyclone operation

was changed to constant pressure and the vortex finder size was decreased.

The combined strategies improved energy efficiency and allowed higher SAG mill power utilisation. The

additional power has been used to increase throughput by 2.4 per cent while achieving a 27μm reduction in

product size (P80) to gain downstream recovery improvements. The reduction in grind size has been

achieved with only 6.8 per cent increase in specific energy consumption because of a 6.5 per cent increase

in grinding efficiency. The circuit product size is also notably more consistent due to the improvements made

to the cyclones, providing benefit to the downstream flotation circuit. A significant decrease in ball

consumption was also gained, saving hundreds of thousands of dollars a year in operating cost.

This paper discusses the circuit design, start up, and details the changes made during the optimisation

and why these were successful.

AUTHOR DETAILS

B PUTLAND (1), I LOVATT (2), A CERVELLIN (3) AND D SCHWANN (4)

(1) FAusIMM, Principal Metallurgist, Orway Mineral Consultants (WA) Pty Ltd, Perth WA 6004. Email: This email address is being protected from spambots. You need JavaScript enabled to view it.

(2) MAusIMM(CP), Lead Metallurgist, Orway Mineral Consultants (WA) Pty Ltd, Perth WA 6004. Email: This email address is being protected from spambots. You need JavaScript enabled to view it.

(3) MAusIMM, Senior Metallurgist, Evolution Mining Limited, Townsville QLD 4810. Email:

This email address is being protected from spambots. You need JavaScript enabled to view it.

(4) MAusIMM, Group Manager – Processing and Metallurgy, Evolution Mining Limited, Perth WA 6000. Email: This email address is being protected from spambots. You need JavaScript enabled to view it.

ACKNOWLEDGEMENTS

CEEC acknowledges and thanks The Australian Institute of Mining and Metallurgy for organising the 14^thAusIMM Mill Operators’ Conference (MillOps 2018). 

Abstracts can be found at the MillOps 2018 website.