Platinum metals are catalysts for change
Fuel cells offer future demand for precious, industrious PGMs Critical Minerals Alliances - September 2021
Last updated 9/16/2021 at 9:28am
From jewelry at a black-tie soiree to scrubbing harmful emissions from the exhaust system of a farm truck, the six platinum group metals – platinum, palladium, rhodium, ruthenium, iridium, and osmium – are metals that are both precious and critical to the United States and Canada.
Extremely rare, durable, and with a brilliance that does not tarnish, platinum and other metals in its group are a treasured choice for high-end jewelry that stands the test of time.
Three of the platinum group elements – platinum, palladium, and rhodium – are also minted into coins and bars for investment purposes, further solidifying the group's role as precious metals.
While scarcity and beauty already make PGEs highly valued, it is more its industrial applications in the automotive, petrochemical, and electronics industries that serve as the catalysts that drive the price of these precious metals to highs on the cusp of $30,000 per ounce, in the case of rhodium.
"PGEs are indispensable to many industrial applications but are mined in only a few places," the U.S. Geological Survey inked in the PGE section of a 2018 critical minerals report. "The availability and accessibility of PGE supply could be disrupted by social, environmental, political, and economic events."
It is this combination of rarity, industrial need, and potential supply disruptions that lands PGMs firmly on the USGS list of 35 minerals and metals critical to the U.S.
Catalysts for change
The list of properties that make PGMs indispensable to global industries is long – exceedingly resistant to wear, tarnishing, and chemical attack; able to endure high temperatures; and excellent electrical stability are near the top of this list. It is this group of metals' catalytic properties, however, that are cherished above all the rest.
"The leading domestic use for PGMs was in catalytic converters to decrease harmful emissions from automobiles," USGS wrote in its Mineral Commodity Summaries 2021. "Platinum group metals are also used in catalysts for bulk-chemical production and petroleum refining; dental and medical devices; electronic applications, such as in computer hard disks, hybridized integrated circuits, and multilayer ceramic capacitors; glass manufacturing; investment; jewelry; and laboratory equipment."
As fossil fuel-burning cars give way to electric mobility, so goes the need for catalytic convertors. E-mobility, however, is also making use of the catalytic properties PGMs have to offer.
Fuel cells being manufactured for large trucks, busses, trains, ships, and even airplanes take advantage of the PGMs catalytic properties to split hydrogen molecules into electrons that create a flow of electricity and protons that unite with oxygen to produce water vapor exhaust and heat.
Earlier this year, Wabtec Corp. signed an agreement to use General Motors' Hydrotec fuel cell and Ultium lithium-ion battery technologies to electrify locomotives.
"The rail industry is on the cusp of a sustainable transformation with the introduction of batteries and hydrogen to power locomotive fleets," said Wabtec President and CEO Rafael Santana. "Our FLXdrive locomotive, the world's first 100% battery-powered locomotive, has proven its potential to slash carbon emissions by up to 30% when operating at 6 MWh (megawatt-hours). But we can't stop there. By working with GM on Ultium battery and Hydrotec hydrogen fuel cell technologies, we can accelerate the rail industry's path to decarbonization and pathway to zero-emission locomotives by leveraging these two important propulsion technologies."
In addition to further commercializing both its hydrogen fuel cell and lithium battery technologies, the collaboration with Wabtec offers GM and other users of North American railroads the opportunity to lower the carbon footprint of receiving raw materials and parts, and then delivering finished products to customers.
"Rail networks are critical to transportation and to GM's ability to serve our customers across North America, and Wabtec's bold plan to de-carbonize heavy haul and other locomotive applications helps advance our vision of a world with zero crashes, zero emissions and zero congestion," said GM President Mark Reuss. "Wabtec's decision to deploy GM's Ultium battery and Hydrotec hydrogen fuel cell systems further validates our advanced technology and demonstrates its versatility."
GM also has deals to install its hydrogen fuel cells for powering electric 18-wheelers.
While GM and others have worked to minimize the amount of PGMs needed for hydrogen fuel cell technology, much like the catalytic convertor industry has found, the best replacement for a platinum group metal is one of the other platinum group metals.
As such, PGMs are expected to once again be catalysts for change as the world transitions from scrubbing harmful emissions from burning fossil fuels to generating electricity and water by splitting hydrogen molecules.
The most valued of the PGMs is rhodium, a sliver-colored metal that is extremely resistant to corrosion and highly reflective – qualities used to add luster to jewelry, mirrors, and even searchlights.
As cherished as it is for aesthetics, the largest use for rhodium is as a catalyst to scrub carbon monoxide, hydrocarbons, and nitrous oxide from the exhaust of automobiles and petroleum refineries.
The combination of beauty and work ethic ranks rhodium among the most valued metals on the planet, rocketing to an astronomical high of US$27,000/oz in March 2021, a more than 500% climb in a year. By the end of July, the price for an ounce of rhodium had settled to around US$17,000.
It is platinum and palladium, however, that are most commonly used as catalysts to reduce harmful emissions from automobiles. As a result, the auto sector has shifted its preferred catalytic metal depending on price.
"Palladium has been substituted for platinum in most gasoline-engine catalytic converters because of the historically lower price for palladium relative to that of platinum," USGS penned in its annual Mineral Commodity Summaries.
This shift has driven the price of palladium to around US$2,700/oz at mid-2021, while platinum prices were hovering around US$1,100/oz.
Iridium sells for around US$5,500/oz and ruthenium is roughly US$750/oz. Reliable prices for osmium are unavailable due to its scarcity.
Practically all of the 603,000 oz of palladium and platinum mined in the U.S. during 2020 was produced at the Stillwater and East Boulder operations about 85 miles southwest of Billings, Montana.
Going into 2021, Stillwater and East Boulder hosted 58.2 million metric tons of proven and probable reserves averaging 14.4 g/t (26.9 million oz) of palladium and platinum.
Sibanye-Stillwater, the South Africa-based miner that owns Stillwater, estimates that this is enough reserves to continue producing PGMs until 2059.
In addition to mining, Sibanye-Stillwater recycles large quantities of PGMs from spent automotive catalytic converters at its Columbus Metallurgical Complex, a smelting and base metal refinery between Stillwater mine and the town of Billings.
During 2020, the Columbus complex processed and recycled 840,170 oz of palladium, platinum, and rhodium from spent catalytic converters.
Overall, roughly 1.8 million oz of platinum and palladium was recycled in the U.S. last year.
With only one PGM mining operation in Montana, the U.S. relies on other countries – primarily South Africa and Russia – for roughly 70% of its platinum and 40% of its palladium.
The third-largest producer of mined PGEs behind Russia and South Africa, Canada produces roughly 1 million oz of PGMs per year – 690,000 oz of palladium, 260,000 oz of platinum, 24,000 oz rhodium, 16,000 oz ruthenium, and 12,000 oz iridium.
Roughly 75% of Canada's platinum metals are mined in Ontario, which is home to the only primary PGM mine in the country. The rest are produced as a byproduct of nickel mining.
Impala Canada's Lac des Iles Mine, northwest of Thunder Bay, Ontario, is the only primary PGM producing operation in Canada. While very little public information on this mine is available since global PGM miner Implants Group acquired Lac des Iles Mine, during 2019 this operation produced roughly 230,000 oz of palladium, the primary metal at the mine.
At the end of 201,8 Lac des Iles hosted 40.9 million metric tons of proven and probable reserves averaging 2.31 grams per metric ton (3.04 million oz) palladium, 0.21 g/t (274,000 oz) platinum, 0.17 g/t (229,000 oz) gold, 0.07% (64 million pounds) nickel, and 0.06% (55.1 million lb) copper.
The Sudbury region of eastern Ontario – where global miner Vale has five mines, a mill, a smelter, a refinery, and nearly 4,000 employees – is also rich in PGMs associated with the nickel mines for which this area is renowned.
PGMs are also produced as byproducts of nickel mines in the Canadian provinces of Newfoundland-Labrador, Quebec, and Manitoba.
Total exports of PGMs and PGM-related products from Canada were valued at $1.65 billion in 2019, with the U.S. receiving more than 76% of those exports.
Besides the PGM-rich regions of Montana and Ontario, along with the platinum metals being produced as byproducts of nickel mining in Canada, there are some areas of North America prospective for future sources of this group of high-priced critical metals.
A special category of PGM-hosting deposits that partially derive their name from Alaska – Ural-Alaska-type ultramafic complexes – hint at the prospectivity for this group of industrious precious metals across the Last Frontier. The geological terrane that hosts these PGM prospective intrusive bodies, however, extends beyond Alaska and well into western Canada.
Known as the Wrangellia Composite Terrane, this microcontinent is considered to be a prime hunting ground for the suite of platinum metals that arcs more than 1,250 miles across the breadth of Alaska, through southern Yukon, and down the Southeast Alaska Panhandle and western side of British Columbia.
The most advanced PGM deposit along the Wrangellia Terrane is Nickel Shäw (formerly known as Wellgreen) in southeastern Yukon, about 60 miles east of the Alaska border
According to a 2018 calculation, Nickel Shäw hosts 323.4 million metric tons of measured and indicated resources averaging 0.26 g/t (2.65 million oz) palladium, 0.2 g/t (2.63 million oz) platinum, 0.27% (1.88 billion lb) nickel, 0.16% (1.11 billion lb) copper, and 0.015% (107 million lb) cobalt.
Nickel Creek Platinum Corp. is exploring 11 high-priority targets that could add to this resource as it continues to optimize plans for developing a mine at Nickel Shäw.
There are intriguing signs that similar PGM-nickel-copper-cobalt deposits may be found in the Alaska portion of Wrangellia, such as the Man property about 250 miles northwest of Nickel Shäw.
Grab samples with extremely high concentrations of PGMs and associated metals have historically been collected by Pure Nickel Inc., the former explorer of this property. One particularly high-grade rock collected at Man contained 13.6% nickel, 2.9% copper, and 26 g/t PGMs.
While these samples are abnormally high-grade due to the selectivity of geologists collecting the most metals-rich samples they come across, such samples show that there are highly enriched metal layers nearby.
The PGM and nickel potential of this section of the Wrangellia Terrane stretching across Southcentral Alaska has attracted the attention of global miners such as MMG Ltd.
In 2013 and 2014, MMG investigated three large blocks of state of Alaska mining claims that follow an arc south of the Alaska Range.
The Peninsular Terrane, a subsection of the Wrangellia Composite Terrane that stretches along the Chugiak Mountains in Southcentral Alaska, is also known for its platinum potential.
New Age Metals Inc. has advanced early staged exploration at Genesis, a 10,240-acre PGM-nickel-copper project that lies alongside a paved highway about 75 miles north of the deep-water port city of Valdez in the Peninsular Terrane.
Sampling of one drill-ready target at the Sheep Hill prospect on Genesis returned up to 2.4 g/t palladium, 2.4 g/t platinum, 0.96% nickel, and 0.58% copper.
Bernard Mountain, about 4.7 miles west of Sheep Hill, hosts a separate style of chromite mineralization where samples with up to 2.5 g/t palladium and 2.8 g/t platinum have been collected.
New Age is also advancing the multi-million-oz River Valley palladium project about 60 miles Northeast of Sudbury, Ontario.
Following the Wrangellia Terrane as it arcs south, the entire Southeast Alaska Panhandle is prospective for PGM deposits.
This includes the historic Salt Chuck Mine, which produced 300,000 metric tons of ore averaging 0.95% copper, 1.96 g/t palladium, 1.12 g/t gold, and 5.29 g/t silver during operations from 1915 to 1941, according to U.S. government summaries (1948).
Though Salt Chuck was never put back into production after its wartime shutdown, a 7,000-meter-by-1,600-meter mafic-ultramafic igneous complex is prospective for the metals recovered at the bygone mine.
Duke Island, about 70 miles southeast of Salt Chuck is another PGM-rich project on the panhandle.
Group Ten Metals, the company exploring the Duke Island project, said the abundance of copper-nickel-PGE sulfide mineralization found there is unlike any known Ural-Alaska complex.
Surface rock samples collected from Dukes Island have returned grades as high as 1.95% copper, 0.25% nickel, and more than 1 g/t PGM.
Group Ten Metals is also exploring PGM projects adjacent to Nickel Shäw in the Yukon, in the Stillwater area of Montana, and in southeastern British Columbia.
Goodnews in Alaska
Goodnews Bay is another area of Alaska that is a past producer of PGMs and has future potential that intrigues the USGS.
About 120 miles south of Bethel, the Goodnews Bay region of Southwest Alaska was the primary domestic source of platinum in the U.S. for roughly five decades. This platinum, however, was not mined directly from an ultramafic complex. Instead, it was recovered as placer nuggets and sands in streams that eroded one of these orebodies.
Yup'ik residents of the area, Walter Smith and Henry Wuya, first discovered platinum in these streams in 1926.
This discovery led to a claim-staking rush followed by several small-scale mining operations. Goodnews Bay Mining Co. consolidated the platinum producing claims and operated a bucket-line dredge from 1937 to 1978, accounting for most of the roughly 650,000 oz of platinum that has been mined from the streams in this area.
High PGM prices have sparked renewed interest in the Goodnews Bay placer deposits over the past decade. This interest has included using modern equipment and techniques to recover platinum left behind by the dredge.
In addition to additional PGMs remaining in the streams of this platinum-producing area of Southwest Alaska, USGS geologists believe there could be significant marine placer platinum deposits just offshore.
"Undiscovered marine placer deposits could be associated with paleochannels or beach deposits in the Goodnews Bay region in Alaska," USGS penned in the PGE chapter of its 2018 critical minerals report. "A geophysical survey indicates the presence of ultramafic rocks offshore, which could be a source of placer platinum."
In addition to what might be found in the ocean downstream from these historical placer deposits in Goodnews Bay, there has been interest in finding the lode source upland from Salmon River and its platinum-bearing tributaries.
A Ural-Alaska-type ultramafic body on Red Mountain, which is being drained by these PGM-rich streams, is believed to be the lode source of the historic placer production that provided the primary domestic source of platinum to the U.S. for nearly 50 years.