Know your rhodium from your rhenium? These crazy rare metals could put miners on the map
Link copied to
Were you always a little strange? Perhaps a bit different in high school..? Didn’t get to hang out with the cool and popular crowd?
Well, just like a forlorn hipster who blooms on a college campus, many of the weirdest metals formerly shunned by all but metallurgical geeks, specialty players and of course China, are suddenly finding themselves wildly popular.
Most investors in mining, metals and resources would have little idea what scandium is.
But Rio Tinto (ASX:RIO) is suddenly interested.
It will pay US$14 million ($21 million) to take the Platina project in New South Wales off the hands of junior explorer Platina Resources (ASX:PGM).
The catalyst for Rio Tinto was the realisation of its scientists at its Sorel-Tracy technology centre in Quebec that it could extract scandium oxide from titanium dioxide slag to monetise its waste.
That led to the development of a 3tpa plant, which can be scaled up to 12tpa going forward. If that sounds tiny, it’s not really.
It made Rio the only scale producer of scandium oxide in North America and one of the largest in the world.
A critical mineral in the United States, Canada, Australia and the European Union, scandium has historically attracted prices of between US$3800-5000/kg and measures total global production not in millions or thousands but in the tens of tonnes.
Used with solid oxide fuel cells and lightweighting alloys to strengthen aluminium in cars, aeroplanes, sporting goods and more, a handful of ASX listed explorers like Sunrise Energy Metals (ASX:SRL) and Ardea Resources (ASX:ARL) could produce scandium oxide as a by-product of nickel and cobalt mines.
But as far as standalone producers, Rio has mostly drained the barrel with its purchase of the Platina deposit, which could double its production profile once open and scale up to 40tpa over its 30-year life.
It begs the question, which other explorers are sitting on deposits of other weird and wonderful specialty metals that, beauty being in the eye of the beholder, could be worth more than the sum of their parts?
Sometimes categorised with rare earths because this element is often found in carbonatites alongside deposits of rare earth metals, niobium is highly resistant to corrosion, heat and wear with 90% of the metal used as a micro alloy with iron in the steel industry.
A superconductor at extremely low temperatures, it’s also used in superconducting magnets in MRIs, nuclear equipment and the Large Hadron Collider, making it a key metal in unlocking the secrets of the universe, despite the fact it is rare and lightly traded.
Ferroniobium makes up around 90% of the market for the metal and trades at an uber premium $45,000/t.
A critical mineral in Australia, as of 2018 there were just 58,000t of Australian niobium ore reserves, according to Geoscience Australia, all of them in natrobionite within the polymetallic Dubbo deposit owned by Australian Strategic Materials (ASX:ASM), an amalgam of rare earths and zirconium where the niobium is an afterthought.
That is almost certain to change with the arrival of boom explorer WA1 Resources (ASX:WA1).
Trading at $3.11 and a market cap of over $110 million, WA1 has seen its shares lift more than 1800% (18x for those playing at home), since revealing high grade niobium hits at its West Arunta project on WA’s border with the NT in October last year.
Rio Tinto — them again — are actively exploring to the south, below where WA1 has found two mineralised carbonatites at Luni and P2.
Should WA1’s drill hits, grading up to 5% niobium oxide, coalesce into a significant resource it could command a real scarcity premium.
Just two mines in Brazil, one owned by CBMM responsible for supplying the vast bulk of the market and the other controlled by China’s state owned China Molybdenum, produce almost 90% of global primary niobium. A single mine in Canada produces most of the rest. No new ones have been developed since Watergate.
A handful of other companies have niobium holdings, either as primary resources or by-products.
Rare earths explorer RareX (ASX:REE) is investigating potential ways to extract value from its secondary niobium and scandium inventory alongside its main phosphate and NdPr products from the massive Cummins Range resource.
Over in Malawi Globe Metals and Mining (ASX:GBE) boasts one of the most advanced niobium assets on the market, the Kanyika niobium-tantalum project, which contains a resource of 68Mt at 0.283% niobium.
There are a number of companies with ground in and around WA1 as well, while a number of rare earths explorers, like Gascoyne focused Reach Resources (ASX:RR1) and Lanthanein Resources (ASX:LNR) have also intersected strong niobium grades associated with rare earths mineralisation.
Borates have a tonne of different industrial uses from glass, fibreglass, flame-retardants and ceramics to detergents, wood protection, fertilisers and pesticides.
And they are another area where Rio Tinto with its vast and unusual array of assets looms as a potential acquirer of some novel assets.
Largely mined in California and Turkiye, commercial quantities of the commodity are sparse, but have been produced for 135 years at Rio’s operations in the Mojave Desert.
Located since 1927 in the town of, wait for it, Boron, in America’s most populous state, Rio’s plant produces a large quantity of calcium free sodium borates ideal for agricultural use as well as 30% of the global demand for refined borates.
At around 1Mt the operation is in decline with reserves set to expire in 2042, with the Eti Maden operation in Turkiye the only other sizeable producer.
Boron is an essential element for plant growth, but its use in heat resistant fibreglass and unique properties also make it a future facing commodity for the renewable revolution, with growing use as an anti-reflective material in solar panels.
There is one standout ASX-listed stock in the field in 5E Advanced Materials (ASX:5EA).
Formerly known as American Pacific Borates, 5EA is knocking on the door of first production from its 5E Boron Americas complex from a resource containing 370Mt at 8.22% boric acid and 0.17% lithium carbonate equivalent.
With the kicker of lithium production as a by-product, it is one of just six potential boron mining projects in the global pipeline despite expectations demand will rise 10x over by 2050, and is located in the backyard of Rio’s declining, non-core boron operations.
Marketing chief JT Starzecki said the plan is to eventually bring the production of downstream materials like boron carbide — 80% dominated by China — back to the United States.
“Certainly one of the concepts we’re playing into at least as a US-based company is moving downstream, so the production of boric acid but also the production of advanced materials,” he said at the Future Facing Commodities conference in Singapore last month.
“Boron does have a lot of military and aerospace applications, boron nitrides, boron carbides, tank armour, kevlar, all of that has an input of boric acid.
“We’re in a unique situation in that the US military tends to buy all of that product that’s essentially mined in California, sent to China for processing then is brought back to the US or military applications.
“Our plan is to not only have a captive supply of boric acid but also produce a certain amount of advanced downstream derivatives to lessen that supply (risk) and bring more of the processing back into the US.”
Rio’s own Jadar project in Serbia would produce a sizeable chunk of boric acid — 160,000tpa — alongside 58,000t of lithium carbonate from a rare mineral known as jadarite. But it’s been held up in development hell since protests forced the hand of the Serbian Government, which cancelled a key licence there in 2022.
A number of other lithium developers have boron rich resources and could play in the tightly held market.
Ioneer (ASX:INR) will produce boric acid as a by-product of its lithium operations at the Rhyolite Ridge mine in Nevada, which is on the fast track to production after the Department of Energy in the United States announced a conditional commitment to provide up to US$700 million in the form of a low-cost loan to get it off the ground.
Rhyolite Ridge is estimated to contain 1.3 million tonnes of lithium carbonate and 12.4 million tonnes of boric acid.
Once in operation, the project is set to produce 24,000 tonnes per year of lithium carbonate and around 192,000 tonnes per year of boric acid.
Antimony rose to prominence during the Second World War and still ranks as one of the most important commodities for the defence sector globally.
A silvery, brittle metalloid and rarely found in its native metallic form, it is usually extracted primarily from stibnite, containing 72pc antimony and 28pc sulphur, to form more than 100 different minerals.
Common to many metals on this list, antimony has anti-corrosive and also fire-proofing qualities that make it a key component in military clothing, tanks and armour-piercing bullets as well as renewable and nuclear energy and tech devices like smartphones, semiconductors, cars and computers.
It is also primarily mined and processed in China, a big red flag for governments in the West.
Australia has just one significant producer, the Costerfield mine in Victoria, a gold operation owned by TSX-listed Mandalay Resources which counts among the world’s top five antimony suppliers.
But explorers in the gold and antimony rich Bendigo goldfields could be following in its footsteps.
$48 million capped Southern Cross Gold (ASX:SXG) is just 54km north west of Costerfield at Sunday Creek, which transported ore to Costerfield back in World War One.
Antimony appears to run throughout the mineralisation at Sunday Creek, where SXG recently had as many as four rigs testing the orebody at depth.
Nearby Nagambie Resources (ASX:NAG), which has the benefit of owning its own processing plant, believes it has discovered one of the highest grade antimony orebodies in the world at its C1 and C2 zones, with average drill interceptions in the order of 6% Sb to date.
The explorer says it is aware of only one Russian mine with a higher grade.
Also on the ASX antimony list is Kiwi explorer Siren Gold (ASX:SNG), which boasts over 1Moz of gold resources in the Land of the Long White Cloud.
Led by well known mining identity Brian Rodan, the first diamond hole at the Auld Creek prospect recently intersected both the Fraternal and Bonanza shoots at the site, with the intercept in the Fraternal Shoot striking a best hit of 20.8m at 5.9g/t gold and 2.6% Sb for 12g/t AuEq from 116.2m including 4.6m at 10.7g/t and 3.9% Sb for 19.9g/t AuEq.
Wild story about rhenium.
It was actually the last naturally occurring element on Earth with a stable isotope to be discovered, in other words the last non-radioactive substance to be found.
Found by three German scientists who eventually extracted just 1g of rhenium from 660kg of the porphyry mineral molybdenite, until the late 60s three-quarters of production was used in research to develop refractory metal alloys — alloys extremely resistant to heat and wear.
Nowadays the rhenium market is unsurprisingly tiny, with Data Intelligence saying world mined production totals around 50 tonnes. Compare that to ~1.5Bt for the most traded metal in iron ore.
With its massive military industrial complex, the US is the biggest user of the critical metal, importing around 40t of the stuff and producing around 8t domestically.
More than 80% of the less than US$100 million per annum market is used in high temp superalloys used to make turbine blades for jet engines.
As might be expected, since it was initially extracted from molybdenite, rhenium is commonly associated with moly and found in porphyry copper systems.
There is one major rhenium and molybdenum deposit known in Australia, the Merlin project in Queensland sold by Turquoise Hill Mining’s Australian subsidiary Inova Resources to China’s Chanxi Donghui Coal Coking and Chemicals Group in 2013.
Turquoise Hill, now wholly owned by Rio Tinto, is valued for its 2/3 share of the Oyu Tolgoi copper-gold mine in Mongolia.
Outside of that a handful of explorers have rhenium in their portfolios. Handy if they can find a way to develop mines where it can be extracted, with prices tracking around US$1500/kg.
Hammer Metals (ASX:HMX) is one of the few listed companies with declared resources of rhenium.
Its Kalman deposit near Mt Isa in Queensland contains 39.2Mt of ore at 1.07% copper equivalent, including 0.53% copper, 0.27g/t gold, 0.1% molybdenum, 1.5g/t silver and 2.1g/t rhenium.
That comes to 208,000t Cu, 343,200oz Au, 38,000t Mo, 1.92Moz Ag and 84,100kg Re.
“Molybdenum concentrates with rhenium require roasting to capture the rhenium from the process off-gas. There are several offshore facilities that process molybdenum concentrates,” the company says.
“Because of the relatively small market for Re there is limited public information available for the payments of credits for rhenium. Enquiries by the company provides the company with sufficient confidence to believe that a credit for the rhenium content of the molybdenum concentrate can be obtained.”
Chilean copper explorer Culpeo Minerals (ASX:CPO) announced in August last year a multi-element analysis of a drill hit containing 85m at 1369ppm molybdenum and 0.77ppm rhenium.
“We recognised early on that Lana Corina is a high-grade copper-molybdenum system and as expected, the multi-element analysis of drillhole CMLCD003 has identified significant rhenium grades of up to 9.55ppm Re associated with the high-grade molybdenum zone which is hosted within a silica cupola deeper in the hole,” CPO MD Max Tuesley said at the time.
“Rhenium is a strategic metal used in jet engines and other military applications as well as to produce high-octane fuels with both the Australian and United States governments identifying rhenium as a critical mineral and these results indicate the potential that rhenium may add further value to the project.
“The company intends to undertake further multi-element analysis to fully understand the distribution of rhenium at Lana Corina.”
There are a whole bunch of platinum group metals that could be included in this list, but rhodium may be the most interesting of the lot.
A silvery-white anti-corrosive metal regarded as a rarer cousin of platinum and palladium used to plate jewellery and in catalytic converters, rhodium is highly exposed to supply troubles in South Africa, home to the bulk of global PGM production.
Rhodium threatened all time highs of over US$30,000 per ounce a couple years ago. Nowadays it trades a bit below US$10,000/oz.
But supply chain issues mean a breakout is a possibility, with the market in a 77,000oz deficit according to Metals Focus.
“First and most notably, load shedding and community unrest in South Africa present a risk to mine supply. 83% of globally mined rhodium comes from South Africa, a greater exposure than for platinum or palladium, so any curbing of mine production could lift the rhodium price,” they say.
“Additionally, there are downside risks to autocatalyst scrap. Reduced supply of end-of-life vehicles, holding of autocatalyst scrap by collectors owing to lower prices, or disruption to supply chains (as the stolen autocatalyst scandal increases scrutiny on origin of material) could limit supply, benefiting the price.
“Lastly, any potential delays or fundamental changes to the EU ICE vehicle ban, set to take place in 2035, following Germany’s last-minute pushback to the legislation, could benefit rhodium demand and expectations for the metal, also lifting the price.”
Rhodium is a small but valuable component of the 6Moz 5E PGM resource at Podium Minerals’ (ASX:POD) Parks Reef resource in WA, one of the few standalone PGM stocks on the ASX.
Zimplats (ASX:ZIM), an ASX-listed Zimbabwean subsidiary of Impala Platinum, is a significant rhodium producer, selling 5702oz in the March quarter from its platinum and palladium dominant operations in the southern African nation.
There are other companies who have found the metal but are yet to get it into a resource, including Mark Creasy’s Galileo Mining (ASX:GAL), which has hit rhodium grades as high as 0.13g/t from its exciting Callisto PGM discovery near Norseman.
Caspin Resources (ASX:CPN), which is looking for a follow up discovery to Chalice Mining’s (ASX:CHN) Julimar platinum group elements, nickel and copper find at its Yarawindah Brook project north of Perth, has also found significant rhodium results in multi-element assays.
One drill hit from May 2022 recorded rhodium grades of up to 465ppb in a hole resampled with an intercept of 13m at 0.17g/t Pd, 0.74g/t Pt, 0.11g/t Rh, 0.26% Ni, 0.21% Cu from 101m, including 2m at 0.40g/t Pd, 2.45g/t Pt, 0.41g/t Rh, 0.23% Ni, 0.09% Cu from 112m.
“It’s a pleasant surprise given this is the first time we’ve ever assayed for rhodium and bodes well for the discovery of more mineralisation,” Caspin boss Greg Miles said at the time. “Because of its value, small amounts as low as 100ppb can make a significant contribution to the economics of PGE deposits.”
At Stockhead, we tell it like it is. While RareX, Podium Minerals, Reach Resources, Ioneer and Lanthanein Resources are Stockhead advertisers, they did not sponsor this article.