Ardea Resources has lodged an international patent application for its innovative mineralised neutraliser at its flagship Kalgoorlie nickel project in Western Australia – Goongarrie Hub.
The mineralised neutraliser is the carbonate-bearing saprock which occurs most commonly at the bottom of the nickel-cobalt laterite profile. It contains low-grade nickel-cobalt mineralisation and will be mined as part of a conventional open-pit operation.
The carbonate component acts as a natural acid neutraliser and will replace imported limestone. The company says it will be a significant cost saving and will also result in reduced carbon emissions as it will not be necessary to transport conventional calcium carbonate neutraliser to site.
The neutraliser is also expected to contribute additional nickel-cobalt to the company’s ore reserves.
Ardea says it is a significant research and development breakthrough that is being incorporated into an updated mineral resource estimate for Goongarrie Hub and will also feature in its upcoming prefeasibility study ore reserve.
Following mining, the target carbonate neutraliser is separated from the mineralised saprock by wet screen separation into serpentine-goethite clay fines and magnesite neutraliser scats. The “scats” have the ability to reduce acidity of the mined material.
Compared to traditional nickel laterite operations that transport limestone from the Nullarbor Plains, or from Esperance lime sands, the cost per tonne benefits of the neutraliser will have a significant influence on pit optimisations as the pits are driven deeper in order to access the saprock layer.
The neutraliser model was finalised in 2021 and holes in the company’s Highway metallurgical core drilling program were positioned to test the concept over the full strike length. Metallurgical laboratory results from a bulk core sample assaying 0.8 per cent nickel had a screen beneficiation at 75 microns generating 23 per cent fines assaying at 1.2 percent nickel, with 77 per cent magnesite neutraliser assaying at 0.6 per cent nickel.
Management says good acid neutralisation capacity of the magnesite scats was confirmed in the study.
Ardea initially filed a provisional patent application covering its neutraliser with IP Australia. The company has now also filed an International PCT patent application entitled “Acid Neutraliser Composition” at the World Intellectual Property Office. The international application covers research and development from Ardea’s earlier Australian provisional patent application, in addition to results from its more recent mineralogical and ANC studies.
Management says the filing of the international application gives it the option to pursue patent protection for its technology in more than 150 countries, including Australia, and represents a significant step towards gaining similar protection in countries around the world for major flowsheet refinement.
For the Mineralised Neutraliser circuit, the separation of nickel-cobalt bearing Serpentine-Goethite clay from Magnesite neutraliser by simple low-cost screening is a significant processing breakthrough. By lodging a global patent application covering Ardea’s Mineralised Neutraliser breakthrough, the Company is protecting its hard-won Research and Development Intellectual Property.
Ardea’s Goongarrie Hub is 70km north-west of WA’s established Kalgoorlie-Boulder mining centre. It is the company’s most advanced project within its broader Kalgoorlie nickel project and includes the Scotia Dam, Big Four, Goongarrie South and Goongarrie Hill deposits, with Highway some 30km to the north and Siberia North about 30km to the south-west.
The six deposits are the main source of ore feed for the prefeasibility study that is being finalised. Ardea also has plans to incorporate additional feed from Ghost Rocks and Black Range.
The Goongarrie Hub mineral resource estimate, with a 0.5 per cent nickel cut-off grade, clocks in at 830 million tonnes at 0.71 per cent nickel and 0.046 per cent cobalt for 5.9 million tonnes of nickel and 380,000 tonnes of cobalt, which management says makes it the biggest nickel-cobalt resource in the developed world.
Australia currently boasts the world’s second-biggest reserves of both nickel and cobalt and while Ardea still sits within the ASX small-cap community, its ongoing innovative research and development of its Kalgoorlie nickel program is turning more than a few heads.
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