Mount Burgess Mining: an ASX veteran with modern ideas

This article is a sponsored feature from Mining.com.au partner Mount Burgess Mining Ltd. It is not financial advice. Talk to a registered financial expert before making investment decisions.

There is a war going on. Not the sort with weapons and violence, but with trade restrictions and legislative vigour.

From August, China will clamp down on its exports of gallium and germanium — 2 critically important minerals in the manufacture of semiconductor chips, which allow electronic devices to process, store and receive information. The country’s exporters — with a stranglehold on roughly 60% of germanium and 80% of gallium production worldwide — will need to secure special licences to execute overseas sales.

The move is in response to the West’s own restrictions on equipment necessary to manufacture semiconductor devices, including the US CHIPS and Science Act of 2022, which curtailed exports of high-end microchips and technology to China.

The back-and-forth, legislators claim, comes down to matters of national security. And while China’s latest restrictions are yet to take effect, some are nevertheless paying very close attention.

Nigel Forrester, Managing Director and Chairman of Mount Burgess Mining (ASX:MTB), is one. The company owns the Kihabe-Nxuu Project in Western Ngamiland, Botswana, roughly 700km north-west of the capital Gaborone, which is prospective for zinc, lead, copper, silver, vanadium and — importantly — gallium and germanium.

Botswana calling

Listed on the ASX in 1985, Mount Burgess has an expansive history. Back then, it was focused largely on the discovery of the Red October gold deposit in Lake Carey, Western Australia — in which its 50% stake was later sold to Sons of Gwalia.

From there, Mount Burgess turned its attention to diamonds, picking up a project in Namibia where Rio Tinto (ASX:RIO) had previously done some diamond exploration work in the Tsumkwe region on the border with Botswana. Although 3 kimberlites were discovered, none were diamondiferous.

“But it was during that exercise that we realised our ground in Namibia, which was right up against the Botswana border, was also within a Neoproterozoic belt, which is highly prospective for base metals,” Forrester says.

“And we knew that it spanned the border between Namibia and Botswana. So we went onto the Botswana side and picked up that portion of the ground. We did a lot of base metals exploration on the Namibian side, but we never really got anything beyond the grades that we got from our soil geochemical sampling. 

They say that national boundaries don’t define geological boundaries, but what we found was that all the fold closures in this Neoproterozoic belt are actually on the Botswana side of the border. This is where you get the higher concentrations of mineralisation, in these fold closures.”

Fast forward a decade or 2 and the Botswana project’s 2 deposits — Kihabe and Nxuu, located 7km apart — host resources measuring 18.4 million tonnes and 4.2 million tonnes, respectively, at 2.2% zinc equivalent (ZnEq), based on a cut-off grade of 1% ZnEq.

Gallium and germanium, however, were only assayed in 7 of the 150 holes drilled at the Kihabe deposit and, therefore, were not included in its resource estimate. But Forrester is all the wiser for it now.

“We basically concentrated, in the initial years, only on the zinc, lead and silver,” he says.

“I wish we hadn’t, because we now know — because of escalating prices — that, generally speaking, what you find in zinc deposits is an association with gallium and germanium.”

generally speaking, what you find in zinc deposits is an association with gallium and germanium”

The gallium-germanium factor

Though gallium and germanium are perhaps secondary to better-established commodities like zinc, lead, copper and silver, their influence at the Kihabe-Nxuu Project is potentially significant.

“The reason we’re reasonably confident that both gallium and germanium are going to make a significant contribution to the project is because the gallium and germanium mineralised domains stretch well beyond those of the zinc, lead, silver and vanadium pentoxide. Basically, they have the potential to significantly reduce our waste-to-ore ratios,” Forrester explains.

“What we’ve got to do is the metallurgy. We know the main proportion of gallium and germanium is hosted in micas, and micas are very easy to extract by way of a high-percentage concentrate because they’re very easy to float. 

Basically, they have the potential to significantly reduce our waste-to-ore ratios”

But now we’ve got to work on what minerals those micas are and how we get the gallium and the germanium out, and whether we can get them out on-site. Because if we can get those metals out on-site, then it’s going to have a very significant impact on the project, as I said, because it has such a major contribution to the overall mineralised domains.”

For this, Mount Burgess intends to start at the “very shallow, basin-shaped, totally oxidised” Nxuu deposit, which is shaping up to be a low-cost and low-risk operation, but which also requires another 2,500m of drilling to upgrade it to a measured resource in line with the 2012 JORC code. (The current resource is in the indicated and inferred category.) Once the update is complete and Mount Burgess is in possession of a fully-compliant measured resource, the company can then launch into a pre-feasibility study, which will include bulk metallurgical test work.

Currently, Mount Burgess is able to recover 93% of zinc on-site at the Nxuu deposit through solvent extraction and electrowinning. Almost 85% of vanadium pentoxide can also be extracted on-site through gravity separation, followed by flotation using hydroxamate acid for recovery. Silver, meanwhile, has proven to be recoverable at similar deposits in Australia. But how, exactly, the extraction of gallium and germanium fits in remains a key unknown.

“When we get to a pre-feasibility study, we need to do that bulk test work so we can see what process we need to apply first to get which metals out first,” Forrester says.

“We don’t want to deteriorate our recovery process for zinc or vanadium pentoxide or silver. So it’s going to be a matter of determining what we get out first so we don’t deteriorate the already-known processes that we’ve confirmed, because they’re all different processes. Once we’ve done that, we should be able to go into a definitive feasibility study.”

The road to production

If Mount Burgess can indeed prove the economic viability of gallium and germanium extraction, the rewards could be far more than reduced waste-to-ore ratios.

Both elements have specific properties that are difficult to replicate, making them prime candidates for niche applications. Germanium is useful in space technologies for its resistance to cosmic radiation, and in semiconductors to improve electron flow and thermal conductivity. It can also convert 40% of sunlight into power when used in solar panels.

Roughly 95% of gallium, on the other hand, is used in a material called gallium arsenide, which helps to improve the performance and power consumption of semiconductors. And with the recent uptake of 5G communications, gallium chips are replacing silicon ones to better cope with the heat generated.

Their respective places on the European Union and US lists of critical elements are a testament to their starring role in our age of high technologies, and demand for them is only expected to grow.

And so Mount Burgess has one chief goal in mind: getting the Kihabe-Nxuu Project online. Asked if the company was considering any expansion-related acquisitions, Forrester’s answer was emphatic: “No, we’re not.”

“We’ve got to get this thing up and running. I mean, this project will work, it’s as simple as that. So we need to concentrate and get it going.”

“this project will work, it’s as simple as that”

It was with this need in mind that Mount Burgess beefed up its board with 2 new appointments in January.

Ian Barclay McGeorge — a Fellow of the Geological Society of London and a chartered geologist — is a British national based in Botswana, where he’s principal consultant and co-owner of iQuest Geology, a geological consultancy based in Gaborone. His appointment as Non-Executive Director follows many years of experience exploring in Botswana for diamonds, gold, copper, nickel, iron ore, lithium, and industrial minerals.

Jacob Thamage — also a Non-Executive Director — previously joined the board of the company’s wholly owned subsidiary, Mount Burgess (Botswana), in July 2021. A mining engineer and Motswana national, he was reappointed as CEO of Botswana’s Diamond Hub in July 2021 and took on the role of International Chairman of the Kimberley Process in 2022.

Mount Burgess’s board now consists of 2 mining engineers, Thamage and Harry Warries; a metallurgist, Rob Brougham; and a geologist in McGeorge.

“We obviously went through some severe restrictions during the COVID period,” Forrester says.

“What we need to do now is build up the local content and the people that can contribute to the project so they can run with it on a day-to-day basis.”

All things going to plan, the Kihabe-Nxuu Project should be operational in the next 2 or 3 years.

 

“We’ve got environmental issues that we’ve got to deal with and that sort of thing, but we do get a lot of cooperation from the Department of Mines on that,” Forrester adds.

“We are fortunately in what’s classified as a rural grazing area, so it’s not restricted by high-density population or anything like that. But we’ve still got to go through that whole process and that takes time. As I say, if everything goes to plan, we should be looking at between 2 and 3 years.”

if everything goes to plan, we should be looking at between 2 and 3 years”

For now, though, Forrester knows what needs to be done to get there. He acknowledges that the journey until now has been a long one, but also that Mount Burgess is on the cusp of something potentially significant.

“The 2 most important things right now are to do the metallurgical test work on the gallium and the germanium to see if we can recover it on site, and then also to upgrade the Nxuu deposit into a measured resource so that we can get on with the job,” Forrester explains.

“Once we’ve done that, then we can then go through to a Definitive Feasibility Study.”

At this point, the sky is presumably the limit.

Write to Oliver Gray at Mining.com.au

Images: Mount Burgess Mining Ltd
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Written By Oliver Gray
Originally from Perth, Oliver has a keen interest long-form journalism. He has written for a number of publications and was most recently Contributing Editor of The Market Herald’s opinion section, Art of the Essay.