AVZ notches new record with world’s largest, highest confidence lithium resource
Special Report: AVZ Minerals (ASX:AVZ) can lay claim to yet another record at its Manono project, which now has the largest, highest confidence lithium resource in the world.
The company has increased the level of resources in the top “measured” and “indicated” categories for its Roche Dure deposit by 41.7 per cent.
Mineral resources are categorised in order of increasing geological confidence from inferred to indicated to measured.
A “measured” resource represents the highest level of geologic knowledge and confidence and allows a company to start work to convert the resource to a reserve — discoveries that are commercially mineable.
An “indicated” resource means a company has sufficient information on geology and grade continuity to support mine planning.
The combined measured and indicated resource for Roche Dure now stands at 269 million tonnes at grades of 1.65 per cent lithium, 816 parts per million (ppm) tin and 36ppm tantalum.
The total resource remains the same at 400 million tonnes, but now 67 per cent of it is in the higher confidence categories as opposed to 47 per cent previously.
“This ongoing work shows us that Manono will continue to grow significantly and will be underpinned by a high grade measured and indicated mineral resource for the majority of the Roche Dure pegmatite drilled to date,” managing director Nigel Ferguson said.
“The greatly increased confidence level in sections of the Roche Dure mineral resource is more than sufficient to support the production schedules and financial modelling within the 5Mtpa scoping study, which is now close to completion.”
Even before the upgrade, the Roche Dure deposit was already the largest tonnage and one of the highest grades of undeveloped hard rock lithium resources in the world.
But there is still plenty more lithium potential at Manono, with AVZ earlier this year unveiling a fresh prospect that’s potentially bigger than Roche Dure.
Drilling some 5km northeast of Roche Dure along the mineralised trend, suggests the Carriere de l’Este target could be even bigger than Roche Dure and at a better grade.
Additional drilling will be undertaken within the Roche Dure pit once the pit has been dewatered and after access is gained to the pit floor later this year.
This will allow the potential upgrade of the inferred resources contained within the “wedge” that sits beneath the pit floor, which is not currently accessible to drilling, to indicated or measured once drilling is completed.
This will allow the inclusion of the “wedge” in the mining production schedules from the start of mining operations.
While about 95 per cent of the Roche Dure strike length and depth extent down to 480m have been drill tested, the bulk of the down-dip extensions of the entire 1,600m strike length are still to be tested.
This latest resource upgrade has also reduced the average iron oxide content – a potentially deleterious element – to 0.96 per cent from 0.99 per cent.
Deleterious elements namely iron, phosphorous and fluorine are contained within minerals such as apatite, lithium micas and black tourmaline which are accessory minerals within the pegmatite.
Trace amounts of iron can also be included in spodumene crystals.
Iron oxide is a potential deleterious element in the production of spodumene concentrates for the glass and ceramics industry.
So in this case, less iron oxide is better.
The Roche Dure resource also contains valuable tin and tantalum.
A 2018 MIT study, cited by Rio Tinto Ventures boss Andrew Latham, showed future tin demand spiking on the rise of autonomous and electric vehicles, advanced robotics, renewable energy, and advanced computing and IT.
More tin is required in the world regardless – demand is growing at a steady 2 to 3 per cent from existing tech demand — and there is limited new supply entering the market.
Meanwhile, tantalum is what helps makes electronic devices smaller. It is used in capacitors and it also helps stop corrosion.
The resource contains tin at an average grade of 715ppm (in cassiterite) and tantalum at a grade of 34ppm (in tantalite).
“There is now a better understanding on the distribution of these minerals with low- and high-grade zones being defined,” Ferguson said.
Metallurgical core samples will be sent to Nagrom for planned test work, including reporting of tin and tantalum recoveries.
Ferguson says this is expected to benefit AVZ’s bottom line when both recovered tin and tantalum estimates are included in future financial modelling.
“With Manono confirmed as the world’s largest lithium deposit, we are increasingly confident that the project will continue to develop into production and potentially become a world leading source of lithium and tin,” he said.