Ardea fine-tunes study for higher-octane WA nickel output

Ardea Resources has been busy fine-tuning a definitive feasibility study on its flagship Kalgoorlie nickel project (KNP), unveiling a simpler development blueprint, with work due for completion in the first half of next year.

After wrestling with industry-wide cost escalation and a wave of fresh technical data, Ardea and its heavyweight Japanese-backed partners Sumitomo and Mitsubishi have sharpened the scalpel on their flagship Goongarrie Hub development.

The partners have now ditched a planned 500,000-tonne-per-annum atmospheric leach circuit and instead cranked up the high-pressure acid leach (HPAL) circuit by the same amount, lifting total processing capacity to a punchy 3.5 million tonnes per annum.

Ardea says the streamlined flowsheet not only drives higher throughput, but it will also underpin a smarter product strategy, reshaping the Goongarrie Hub into a leaner, more competitive nickel-cobalt contender on the global stage.

A big part of the thinking behind the change in the flowsheet is the switch from the planned sale product from a mixed hydroxide precipitate to a mixed sulphide precipitate.

The simpler sulphide product not only fetches a better price in the market, but it also opens a broader customer base, allowing for greater flexibility in marketing the remaining 25 per cent offtake entitlement not already going to the Japanese majors. The move will give Ardea a foothold into established nickel sulphide smelters and refineries around the world.

The new study also identified the quickest pathway to early cash flows from the various deposits. The first decade of mining will now be shaped around higher-grade, near-plant goethite material. By focusing on ore from the project’s Goongarrie South, Big Four, and Scotia Dam, haulage routes will be shortened, reducing operating risk and bringing the strongest margin product forward.

Several key design improvements have now been fully validated, most notably the simplified HPAL-only flowsheet and the move to MSP as our sale product. These enhancements position the Goongarrie Hub as a robust, long-life, globally competitive nickel-cobalt operation.

Beyond the locked-in changes, Ardea says the partners also have their eye firmly fixed on a set of additional upside levers. On the processing front, engineers are looking at whether the crushing and grinding circuit could be simplified by relying more on semi-autogenous grinding (SAG), using low-grade rock from near the surface to help grind the ore.

If the idea passes muster, the move could reduce both capital outlay and operating costs tied to the grinding process, while also using material that would otherwise be waste and not suitable for HPAL processing.

Ore transport is also under the microscope, with slurry pipelines from satellite pits being considered as an alternative to constant road haulage. If it stacks up, that option could again reduce costs, ease highway traffic and unlock more efficient mine-void backfilling strategies for the waste.

Adding to Goongarrie’s credentials, scandium and gold are now being assessed as potential by-products, with modelling examining the site layout for a future scandium refinery should the economics and markets line up.

Just 80 kilometres from Kalgoorlie, Ardea’s Kalgoorlie nickel project hosts the world’s largest undeveloped nickel-cobalt resource, tipping the scales with a colossal 854 million tonnes, grading 0.71 per cent nickel and 0.045 per cent cobalt, for 6.1 million tonnes of contained nickel and 386,000 tonnes of cobalt.

At its core is the Goongarrie Hub, the engine room of the development, which alone hosts 584 million tonnes at 0.69 per cent nickel and 0.043 per cent cobalt. That translates into a formidable 4 million tonnes of contained nickel and 250,000 tonnes of cobalt.

Back in 2023, a pre-feasibility study sketched out a remarkable 40-year mine life churning out around 30,000 tonnes of nickel and 2000 tonnes of cobalt every year, cementing the project as a long-haul player in the global battery metals race.

The updated flowsheet changes have landed amid an increasingly favourable geopolitical backdrop. The Federal Government recently renewed KNP’s “Major Project Status”, highlighting the project’s strategic importance which has helped Ardea engage at a high level with policymakers in Australia, the US and Japan, reinforcing its role in future battery and stainless-steel supply chains.

With the feasibility study now zeroing in on a cleaner, higher-impact development pathway, Ardea appears to be reshaping Goongarrie with cost discipline front of mind and product relevance not far behind.

By cutting complexity, lifting throughput and widening its product and market optionality, the company is recasting its flagship nickel hub as a long-life, geopolitically aligned super-supplier into a world scrambling for secure battery metals.

One of the sure things about huge projects is that small changes can result in massive bottom line increases and by any measure Ardea’s project is huge. Its margins were already off-the-scale when compared to more traditional sulphide nickel projects and this weeks tweaking will likely result in material outcomes.

Is your ASX-listed company doing something interesting? Contact: matt.birney@wanews.com.au