Wiluna transformation ready to begin as it charts three-year path to 250,000ozpa
The first stage of a major expansion of Wiluna Mining Corporation’s Wiluna Gold Mine is nearing completion, with commissioning of a new 750,000tpa flotation circuit set for December this year.
The addition of the new circuit will help Wiluna Mining Corporation (ASX:WMC) ramp up production to a run rate of 120,000ozpa by the end of the 2022 financial year, a major step change for the gold miner.
Construction is 75% complete, with mine development to access new mining areas now 35% of the way there.
Completing the flotation circuit is the first step of a three-year process designed to transform Wiluna from a modest 60,000ozpa cash generating producer of free milling gold to a large-scale gold producer turning out 250,000ozpa from multiple ore sources.
The company on Monday announced the end of a major 175,000m drill program to improve its confidence and extend resources to underpin the Stage 2 expansion, which will be outlined in a feasibility study due by the end of the March Quarter.
Wiluna is one of the WA Goldfields’ great mining centres, with an historic and current gold endowment of more than 11Moz and over 7Moz in total resources, making it the eighth largest gold district in Australia to be consolidated under a single owner.
WMC produced 51,552oz at all in sustaining costs of $1794/oz against a realised gold price of $2627/oz in FY2021.
While that generated a tidy $20 million profit, the project is ready to be scaled up to make WMC a low-cost, large-scale mid-tier producer.
From the middle of next year Wiluna will have the capacity to utilize the 750,000tpa flotation circuit and existing 2.1Mtpa CIP mill to enhance its scale and process 750,000t of sulphide ore and 2Mt a year of retreated tailings from its Wiltails project into 120,000oz of gold concentrate and dore at costs of US$1150-1200/oz.
By 2024 the 750,000tpa flotation circuit will be expanded to 1.5Mtpa to enable WMC to process 1.5Mt of sulphide ore and a further 2Mtpa of tailings.
This should see the company producing at a rate of 250,000ozpa by 2025.
The last major items for the Stage 1 expansion at Wiluna, the main flotation cells, are due to be delivered to site next month.
Concrete work is now done, with structural activities 87% complete, mechanical work 65% complete and piping & electrical work 30% complete.
Meanwhile a tailings retreatment facility, to access a reserve containing 31.6Mt @ 0.6g/t for 579,000oz of gold, is expected to be commissioned in the March quarter subject to environmental approvals.
WMC worked with MACA Interquip to complete a plant layout and capital cost estimation during August.
The work will include the construction of a feed bin and conveyor, a trommel to repulp the tailings using flotation tailings, a lime slaking circuit for pH adjustment utilising existing BIOX equipment, and a pumping system to send the tailings slurry to the existing CIP leach circuit.
Development has begun in the Happy Jack and Bulletin underground mining areas while the Golden Age mine continues to be extended to deliver high-grade free milling ore for the existing Wiluna plant.
Eastern and downdip extensions at Golden Age are being evaluated and developed in the upper section of the mine.
The first ore drives at Bulletin Upper have commenced, delivering sulphide ore in August, with mining of the first two sublevels for sulphide ore development under way and first stope ore expected in October/November.
Around 15,000t of sulphide ore from development is sitting on the ROM pad awaiting the completion of the flotation circuit.
There has been promising news on the metallurgical front as well, with recently completed testwork confirming expected gold recovery from combined flotation and tailings circuits in the range of 92 – 95%, an improvement of greater than 4% from a previously advised Stage 1 feasibility study recovery of 88%.
With the Wiluna operations set to consume more power and water once the expansions are up and running, work is ongoing to continue to improve the environmental, social and governance aspects of the mines.
Renewable power generation studies are continuing heading into 2022, with assessments of the wind resource at the remote mine site ongoing.
A hydrogeological assessment to secure long term water supply has also commenced and will progress through the feasibility study.
Wiluna has appointed ESG specialist Dr Jim Bawdon and community liaison officer Trish Botha to enhance its work with the local community, which includes the Martu Aboriginal People.
Among other things, the company says it is working to eliminate modern slavery from its supply chain and “build a respectful and mutually beneficial relationship with the Martu people”, and prioritise their involvement in employment opportunities, setting up small businesses and community engagement.
“Ms Botha has been very active since her appointment, meeting with several members of the Wiluna community and the local leaders and is working on our first initiative which we will hope to confirm in the next few months,” the company said.
This article was developed in collaboration with Wiluna Mining Corporation, a Stockhead advertiser at the time of publishing.
This article does not constitute financial product advice. You should consider obtaining independent advice before making any financial decisions.