GREENTECH METALS LTD (GRE) - A Historic Reef And Mine Data Could Re-Rate GreenTech Metals

A thin, high-grade reef can be impressive on paper, but it can also be hard to mine at scale. That’s why we sit down with GreenTech Metals CEO James Rattenbury to talk about a different way to view the Munni Munni platinum group metals system in Western Australia’s West Pilbara: not just the reef, but the wider mineralised zones around it that bring copper and nickel into the story.

We walk through what Green Tech Metals is building across a dominant regional footprint, anchored by two projects only about 10 kilometres apart: Munni Munni (PGE with base metals potential) and Whundo (a high-grade copper-zinc VMS asset with overlooked gold). James explains why commodity prices, mining methods, and development benchmarks have shifted since earlier studies, and how that changes what “historic” data can be worth today. We also unpack the practical work underway, including drilling, resampling preserved legacy core, and QA/QC designed to support a JORC 2012 mineral resource estimate targeted for the June quarter.

From there, we look ahead to the 2026 catalyst timeline: Money Money’s re-estimated resource in late June, Whundo’s update by August, drilling news flow from June, and the metallurgical test work needed to confirm a simple concentrate pathway with meaningful PGE credits. If you follow ASX mining, critical minerals, platinum group metals, copper, nickel, and WA exploration, this conversation maps the milestones that could drive a re-rate.

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Transcript

Andrew Musgrave

Welcome again to ASX Briefs, and today we welcome James Rattenbury, the Chief Executive Officer of GreenTech Metals Limited, an exploration and development company building a multi-commodity critical minerals and precious metal hub in Western Australia's premier West Pilbara mining region. James, great to have you with me today, and welcome to the ASX Briefs podcast.

James Rattenbury

Thanks for having me, Andrew.

Andrew Musgrave

Now, James, GreenTech Metals has consolidated a dominant position of over 500 square kilometres in the West Pilbara, a region home to some of Australia's most significant mineral endowments. Can you give the listeners an overview of the company and what you're building?

James Rattenbury

Certainly. GreenTech Metals was listed over four years ago with the Whundo copper asset. This is a historic mine, a VMS project with 6 million tonnes at 1% copper, 1% zinc. Recently in February, we closed on the acquisition of Munni Munni, a historic platinum group metal project. So, a very high-grade reef that has a historic resource of 24 million tonnes at 2.9 grams a tonne PGE for 2.2 million ounces. These two projects are 10 kilometres away from each other in the West Pilbara, and they're 60 kilometres south of Karratha. They're on mining leases and very close to infrastructure.

Andrew Musgrave

Now, James, you're relatively new to the CEO role, having been appointed in February 2026. So, what attracted you to GreenTech and what did you see in the opportunity when you arrived?

James Rattenbury

I'm a geologist by background, and I spent 13 years with Resource Capital Funds, a mining private equity fund, and roles focused on investing in mining companies. I've seen a lot of projects around the world over the last 13 years, and I've also invested heavily in platinum group metal projects globally. What I saw with GreenTech was a fundamentally incredibly attractive resource at a very high grade, an enormous expiration package of ground that I think has upside beyond the resources we've delineated, but also the potential for MA. So, there are regional producers of copper that I think would be very attracted to what we're doing. When I joined, I did my typical two months of private equity style due diligence. So went through everything, spoke to a lot of people familiar with the projects. There's a lot of history. I think the value in Munni Munni and Whundo is reframing what's been done historically in a current context. So, commodity prices are very different to what they were 20 years ago when study work was done on Munni Munni. And Whundo is a historic copper mine, has a very high-grade resource with a lot of upside. So, a lot of things attracted me to Green Tech. I think it's a strong team. We've got Kevin Frost, the geologist that discovered Gonville, advising us. So, I think there's a real credibility to what we're achieving with the de-risking of these projects.

Andrew Musgrave

And the Ferguson Reef has a continuous strike length of 13 kilometres. What does the scale of that reef system mean for the exploration and resource growth potential you see ahead?

James Rattenbury

So, the Ferguson Reef sits on only the northern extent of these 225 square kilometres intrusive. That 13-kilometer strike length is delineated down to a depth of 700 meters, and this is a very continuous reef, similar to what you get in South Africa with the Merensky Reef. But I think the bigger opportunity we're seeing is the zones that sit around the reef that include a lot of copper and nickel. We see a lot of gossan across this large-scale intrusive. Historically, they just focused on the reef itself, which is around three metres thick. And to mine something like that is very difficult in Western Australia. You cannot get the vertical and lateral advance up high enough to justify building a big plant because your mine feed just won't support it. So, we're looking at this very differently. There's around eight to ten meters of mineralization, including a lot of copper and nickel, that sits around that reef. And that lends itself to bulk underground mining and also to open cut mining where the reef is shallow and also has a gentle plunge. So, we're looking at this through a very different lens. And I think demonstrating that approach is what's important to me. I looked closely at Chalice. I looked closely at Terra Metals and at Bravo Mining in Brazil. And these are three very credible platinum group metal plus base metal projects, and that's why they work. They've got the copper, they've got the nickel, but also the high-grade PGE. Chalice and Bravo both have $500 million market caps. Terra has a $300 million market cap. And we're sitting with a $20 million market cap and a lot of upside if we can deliver what we think we can through that de-risking.

Andrew Musgrave
 
 You’ve also just completed a phase one drilling and resampling program at Munni Munni. Can you walk us through what was done and how the program evolved from the original plan?

James Rattenbury

So as part of validating the JORC 2004 resource we have at Munni Munni, and that was drilled to a measured and indicated level of confidence. We have to call it a historic resource because it is not JORC 2012 compliant. To make it compliant, we need to do some QA/QC work. So, we have gone through and added duplicates, blanks, and standards to the sampling and assaying that we've done. And that's based on twinning holes, resampling some old core on site that's been incredibly well preserved, and also doing some infill drilling as well. That program concluded in March, and we had assays back this morning. And we've seen some really incredible numbers from those drill results, up to 8.8 grams a ton PGE and wider zones that include substantial copper and nickel that we expected to see that support our thesis that this project should be considered through that different lens.

Andrew Musgrave

And you've engaged Snowden Optiro to undertake that QA and QC validation that you mentioned of the historic resource data with a JORC 2012 mineral resource estimate targeted for the June quarter. So, what will that updated MRE mean for the company?

James Rattenbury

I think the re-estimation of that resource will look very different to the historic resource. Bearing in mind the historic resource was just focused on that three-meter-wide high-grade reef that's very continuous. So, we're talking about bulk tonnage. So that will be mean substantially more tons, more metal. But obviously a lower grade where we're looking at bulk scale extraction from open pit mining and from underground mining. We will still have a very high-grade underground resource focused on the reef as part of the overall resource complexion. But I think importantly, we we're talking about something much bigger than what was considered historically.

Andrew Musgrave

Following on from the JORC upgrade, what does the expanded exploration program at Munni Munni look like? Where are you targeting next with in-fill and extensional drilling?

James Rattenbury

So, the size of this intrusive is what's really important in terms of going back to some baseline exploration work. So, using geophysics and geochemistry to delineate those copper and nickel sulphide signatures that we think help unlock the value of the bigger opportunity here. So, in addition to that, we'll be doing some more rock chipping, the fixed loop EM to delineate those sulphide zones. We will also continue with the infill and extensional drilling around the reef, particularly where it's shallow. And I think we can pick up a lot of the copper and nickel along with the reef where it's shallow. So that will be RC infill. We'll still have the deeper diamond drilling to target the depth extensions of the reef. And with these reefs, you do see they thicken and get higher grade at depth. So, we expect that, but I think it's also very expensive to drill 700-meter-deep diamond holes to get that information. So, one of the benefits of having all that old core stored on site is we can resample and actually receive a lot of information, geochemical analysis, through the re-assay with that broader suite of metals and signatures within the core that help us work out where we should be targeting those depth extensions.

Andrew Musgrave

Alongside Munni Munni, GreenTech has the Whundo project, a high-grade brownfield of VMS deposit. Can you give us a status update on Whundo and what recent drilling has revealed?

James Rattenbury

So, the Whundo project has always been considered as a small VMS project, and these projects always look like they're going to be easy to make bigger, but VMS, I mean, they're clustered deposits, and often it's challenging to make them grow quickly. We see a lot of potential at Whundo with firstly re-estimating the resource. So, this is a copper zinc resource that never included gold because they didn't assay for it. We know the gold is there. We went through a process of re-assaying for gold last year. We will need to do some drilling, some metallurgical drilling to look at gold recoveries for the NSR calculation. The copper price was also, I mean, half of what it is today when they did the resource work. So, the upside I see is a re-estimation that pushes the pits down, picks up stacked lenses that we know sit below the existing resource shelves. And that's before we look at the depth extension potential at Whundo. I sit next to Julian Hanna in the office I'm in, and he looks at this as a Golden Grove equivalent. So, it just gets better with depth, but it is expensive to drill it to depth. So, we know the copper comes in in sort of more Bornite form as you get deeper, so higher grade, thicker mineralization. But we've got to firstly identify everything we've got that's on surface. And I think this has a lot of upside. So, I think it's been overlooked despite the fact it has been mined recently, and in at current copper prices, I think it makes a lot of sense to spend time on it.

Andrew Musgrave

Okay, James. Now finally, as we look ahead throughout the rest of 2026, what are some of the key milestone’s investors should be keeping an eye on?

James Rattenbury

We'll have the Munni Munni re-estimated resource out in late June of this year, and we'll have the re-estimated Whundo resource out by August of this year. We'll have a drilling program kicking off likely in June and a lot of news flow from that, in addition to the resampling of core as we build that geological understanding of the bigger opportunity. Given these projects are on mining leases, the intensity of drilling and the availability of infrastructure and historic data in terms of Met test work, we do see the potential to fast track these projects into study phase. We do need to do some metallurgical test work. These PGE projects require you to understand what you produce before you go and start thinking about mine planning. And historically, this has been considered as one bulk concentrate, so a copper concentrate with a very high-grade PGE credit. We think that's achievable. It keeps things simple, and that's ultimately what we want to do with Munni Munni. So, I think a lot of news flow, not just the drilling, the resampling, but I think as we re-estimate these resources and build out the bigger opportunity here, that study phase work can materialize very quickly.

Andrew Musgrave

Alright, James. Well, it's been great to chat today to get an update on where the company is at. Looks like there is plenty of upside ahead, and we look forward to further updates from GreenTech Metals in the upcoming months.

James Rattenbury

Thank you, Andrew. Really great to talk through GreenTech. I appreciate it.

Andrew Musgrave

That concludes this episode of ASX Briefs. Don't forget to subscribe, and we look forward to catching you on our next episode.