Commissioning of the coarse ore flotation circuit at Cadia Valley Operations – challenges and successes

Jaques, Vollert, Akerstrom, Seaman

Presented at the AusIMM Mill Operators Conference June 2021

ABSTRACT

In August 2018 the first full-scale pneumatically assisted fluidised bed flotation cells for the recovery of coarse composited gold and copper were commissioned at Newcrest’s Cadia Valley operation in New South Wales. The primary objective of the installation is to recover coarse value-bearing composites that are currently lost to conventional flotation tailings, without additional power input for particle sizereduction to improve mineral liberation.

The Eriez HydroFloat™separator is an aerated fluidised-bed (or teeter-bed) separator that has been demonstrated to increase the recovery of coarse, poorly liberated particles, compared to conventional flotation technology, by combining flotation fundamentals with hydraulically assisted separation. The technology was invented by Eriez in 1997.

At Cadia, composite particles are the principal carrier of gold and copper in the rougher tailings making up 50–60 percent of the contained value in 2–5 percent of the mass. Over 50 percent of the composite particles in rougher scavenger tailings are in the lowest sulphide exposure range <10 percent, where recovery via the existing conventional flotation circuit is poorest at only 30percent.

This poor recovery of composite particles with low surface exposure presented a significant opportunity for the application of HydroFloat™technology in a scavenging capacity. The Cadia Coarse Ore Flotation Circuit is a novel application of aerated teeter-bed technology in sulphide flotation and presented many challenges during the commissioning and subsequent optimisation phases that needed to be solved to achieve successful delivery of the project.

This paper gives an overview of the commissioning and ramp up journey, major operational challenges and solutions, high-level operational strategy and some analysis of the circuit performance to date.

ACKNOWLEDGEMENTS

The authors would like to thank Newcrest Mining Limited for permission to publish this paper. A special acknowledgement is made to the many people who contributed to the successful commissioning and optimisation of the circuit including the Cadia site and corporate metallurgy teams, Ian Clatworthy, Andrew Thompson, David Buchanan and Eriez

AUTHORS

E Jaques1, L Vollert2, B Akerstrom3 and BA Seaman4

1.Senior Plant Metallurgist, Newcrest Mining Limited, Orange NSW2800. Email:This email address is being protected from spambots. You need JavaScript enabled to view it.

2. Senior Metallurgist, Newcrest Mining Limited, Melbourne Vic3004. Email:This email address is being protected from spambots. You need JavaScript enabled to view it.

3. Manager - Ore Processing, Newcrest Mining Limited, Orange NSW 2800. Email:This email address is being protected from spambots. You need JavaScript enabled to view it.

4. Principal Metallurgist, Newcrest Mining Limited, Perth WA6000. Email:This email address is being protected from spambots. You need JavaScript enabled to view it.

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