Highlights of the March 2024 operational update

Exploring the implications of a larger total resource and a more efficient processing route backed by Metso of Finland.


  • The revised mineral resource estimate (MRE) shows a much larger resource.
  • The MRE now includes two broad mineral domains: high-grade greisen and albite granite.
  • The two domains can be mined together using large-scale mining techniques, which will be more cost efficient.
  • Test results show that the mineral processing approach works well on the combination of greisen and granite ore.
  • In the pyro- and hydrometallurgy stage of processing, a new alkaline leach process from Metso of Finland looks very promising.
  • Initial tests show the Metso process is potentially more efficient, with higher lithium recovery rates; the company is now embarking on larger-scale pilot testing of this process.
  • Based on these new developments, the company is currently re-working some of the project parameters to achieve greater scale and efficiency.
  • The bankable feasibility study is expected to be released by the end of 2024.

Full Transcript

Hello, this is Anton Du Plessis, CEO of Zinnwald Lithium. I just wanted to give a brief run through of the highlights of our operational update. It’s a long release, as we’ve been busy on a number of fronts.


The revised mineral resource estimate

One of the highlights was, of course, the MRE update. And I provided an explainer on this in a separate video, you can find on our website, so I won’t dwell on it too much here. But the key point is we’ve shown a much bigger resource that includes two broad mineral domains: the high-grade greisens and the albite granites. What is important about this as we think through the implications for the project is both domains benefit from large dimensions, which makes large scale mining techniques such as sublevel stoping possible. This compares to the more expensive room and pillar method that was contemplated in previous studies.

Also the dimensions of the high-grade greisen domain will allow us to optimise mining in the early years of the project to have a high run-of-mine grade (and by early years I really mean the first 15 years of the project, so quite an extensive period of time).


The mineral processing stage

On mineral processing we completed the pilot scale test at Metso’s facility in Finland. This showed that a mainstream process works well and allows us to process both ore types together with very good recoveries relative to mass pull. Now bear in mind, in the mineral processing circuit, one wants an optimum balance between highest recovery and lowest mass pull. So we think we’ve achieved that balance in these tests.


Pyro- and hydrometallurgy: The new Metso process

On pyro- and hydrometallurgy, we had previously done large-scale pilot test work using a flow sheet we developed with K-UTEC based primarily on high-grade greisen material. We’re doing confirmatory test work to confirm this remains valid for a mixture of high-grade greisen and albite granites, but alongside this we’ve also tested Metso’s alkaline leach process at bench scale.

The results from this test work were extremely encouraging, showing very high recoveries clearly above 95%. Why is this attractive for us? The Metso process has the potential to offer some meaningful benefits in terms of efficiency. Also improved recoveries and significantly less waste material as well as potential to produce several useful byproducts.

The very encouraging early results justify taking this Metso process to pilot-scale testing, which we’re currently embarking on.


Next steps

The combination of these things—the combination of a significantly larger total resource and the promise of a much more efficient process route backed by one of the leading mineral and metallurgical processing companies globally, means that we are reworking some of the project concepts and parameters that go along with that—essentially, so that we can ensure that we can deliver the optimum project in terms of both scale and economics.

As such, we’re focused on delivering our bankable feasibility study by the end of this year. 

Alongside the work that I’ve already mentioned, we’re doing work on our extensive exploration licence portfolio and we’ll have further updates on these as the year progresses. However, advancing the core project is a primary objective and where we will expend most of our our energy and resources.

The broader market backdrop, as well as some of the developments within the EU, such as the CRMA are also very important and a substantial topic in and of themselves. And I will be addressing these in a subsequent video.

Thank you very much for your attention, and we look forward to keeping you informed as to our progress as we continue.

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