IN SUMMARY
Understanding platinum group metals, the rarest of them all
Understanding platinum group metals, the rarest of them all
Platinum is almost never discussed alone. It comes as a sextet with palladium, rhodium, iridium, osmium and ruthenium, collectively the platinum group metals (PGM), whose geology, processing and applications are so intertwined that they are treated as a single family. They are by far the rarest metals in the Earth's crust, present at parts-per-billion levels, and that scarcity, combined with extraordinarily complex processing, makes their per-kilogram environmental impact orders of magnitude higher than common metals. As demand shifts from catalytic converters toward hydrogen fuel cells, this guide, part of Minviro's "Explore the Elements" series, introduces PGM geology, processing routes, markets and the role of LCA.
Platinum is almost never discussed alone. It comes as a sextet with palladium, rhodium, iridium, osmium and ruthenium, collectively the platinum group metals (PGM), whose geology, processing and applications are so intertwined that they are treated as a single family. They are by far the rarest metals in the Earth's crust, present at parts-per-billion levels, and that scarcity, combined with extraordinarily complex processing, makes their per-kilogram environmental impact orders of magnitude higher than common metals. As demand shifts from catalytic converters toward hydrogen fuel cells, this guide, part of Minviro's "Explore the Elements" series, introduces PGM geology, processing routes, markets and the role of LCA.
Platinum is almost never discussed alone. It comes as a sextet with palladium, rhodium, iridium, osmium and ruthenium, collectively the platinum group metals (PGM), whose geology, processing and applications are so intertwined that they are treated as a single family. They are by far the rarest metals in the Earth's crust, present at parts-per-billion levels, and that scarcity, combined with extraordinarily complex processing, makes their per-kilogram environmental impact orders of magnitude higher than common metals. As demand shifts from catalytic converters toward hydrogen fuel cells, this guide, part of Minviro's "Explore the Elements" series, introduces PGM geology, processing routes, markets and the role of LCA.
PGM are the rarest metals in the crust. Found at parts-per-billion levels, most of Earth's platinum group metals sank into the core during planetary formation, leaving only scarce, highly refractory deposits at the surface, always alongside nickel, copper and gold.
PGM are the rarest metals in the crust. Found at parts-per-billion levels, most of Earth's platinum group metals sank into the core during planetary formation, leaving only scarce, highly refractory deposits at the surface, always alongside nickel, copper and gold.
PGM are the rarest metals in the crust. Found at parts-per-billion levels, most of Earth's platinum group metals sank into the core during planetary formation, leaving only scarce, highly refractory deposits at the surface, always alongside nickel, copper and gold.
Supply is extraordinarily concentrated. South Africa's vast Bushveld Complex holds around 70% of global PGM mineral wealth, with Russia, Zimbabwe and Canada (notably the Sudbury meteorite-impact deposit) making up most of the rest.
Supply is extraordinarily concentrated. South Africa's vast Bushveld Complex holds around 70% of global PGM mineral wealth, with Russia, Zimbabwe and Canada (notably the Sudbury meteorite-impact deposit) making up most of the rest.
Supply is extraordinarily concentrated. South Africa's vast Bushveld Complex holds around 70% of global PGM mineral wealth, with Russia, Zimbabwe and Canada (notably the Sudbury meteorite-impact deposit) making up most of the rest.
Their carbon footprint is exceptionally high. Because so little is mined and processing is so complex, platinum can emit tens of thousands of kg CO₂e per kg, compared with roughly ten per kg for nickel, which makes LCA essential for the sector.
Their carbon footprint is exceptionally high. Because so little is mined and processing is so complex, platinum can emit tens of thousands of kg CO₂e per kg, compared with roughly ten per kg for nickel, which makes LCA essential for the sector.
Their carbon footprint is exceptionally high. Because so little is mined and processing is so complex, platinum can emit tens of thousands of kg CO₂e per kg, compared with roughly ten per kg for nickel, which makes LCA essential for the sector.
What PGM are, and why they form together
The platinum group metals are six elements, platinum, palladium, rhodium, iridium, osmium and ruthenium, that are almost always discussed as a set because their geology, processing and uses are inherently linked. They are the rarest metals in the Earth's crust, present at only parts-per-billion levels. The reason lies in planetary formation: PGM are siderophiles, most stable when bonded with iron, so as the iron-nickel core consolidated, the overwhelming majority were drawn to the centre of the planet and locked there. The small amount remaining accessible near the surface is scarce and highly refractory. They reach mineable concentrations only through a specific, rare process: in certain sub-surface conditions PGM become chalcophiles, bonding with sulfur, so when sulfide melts separate from magma they sweep up the PGM alongside copper, gold and other chalcophiles, forming metal-rich ore bodies on cooling. This is how the great deposits of South Africa, Russia and Canada formed, and it is why PGM ores are among the most isolated in the world, always occurring alongside nickel, copper and gold.
The platinum group metals are six elements, platinum, palladium, rhodium, iridium, osmium and ruthenium, that are almost always discussed as a set because their geology, processing and uses are inherently linked. They are the rarest metals in the Earth's crust, present at only parts-per-billion levels. The reason lies in planetary formation: PGM are siderophiles, most stable when bonded with iron, so as the iron-nickel core consolidated, the overwhelming majority were drawn to the centre of the planet and locked there. The small amount remaining accessible near the surface is scarce and highly refractory. They reach mineable concentrations only through a specific, rare process: in certain sub-surface conditions PGM become chalcophiles, bonding with sulfur, so when sulfide melts separate from magma they sweep up the PGM alongside copper, gold and other chalcophiles, forming metal-rich ore bodies on cooling. This is how the great deposits of South Africa, Russia and Canada formed, and it is why PGM ores are among the most isolated in the world, always occurring alongside nickel, copper and gold.
Where PGM come from, and how they're processed
PGM supply is overwhelmingly concentrated in a handful of countries. South Africa's Bushveld Complex, a 66,000 km² formation around 2.1 billion years old, holds roughly 70% of the world's PGM mineral wealth, with significant further reserves thought to lie untapped beneath it. Russia (the Noril'sk-Talnakh ore body), Zimbabwe and Canada also contribute substantially; Canada's Sudbury deposit formed from a massive meteorite impact that melted vast amounts of crust and forced PGM to crystallise around the crater rim. The processing route from ore to refined metal is long and highly specialised: concentration by froth flotation, smelting and converting to a matte, leaching to remove base metals, and complex refining to separate and purify each individual PGM, demanding because the six share such similar chemistry and the end uses require extremely high purity. The whole process is energy-intensive, reagent-heavy, and often runs on electricity with a low renewable share. One environmental upside is that a single PGM supply chain typically yields a basket of valuable metals together, which is favourable in life cycle terms.
PGM supply is overwhelmingly concentrated in a handful of countries. South Africa's Bushveld Complex, a 66,000 km² formation around 2.1 billion years old, holds roughly 70% of the world's PGM mineral wealth, with significant further reserves thought to lie untapped beneath it. Russia (the Noril'sk-Talnakh ore body), Zimbabwe and Canada also contribute substantially; Canada's Sudbury deposit formed from a massive meteorite impact that melted vast amounts of crust and forced PGM to crystallise around the crater rim. The processing route from ore to refined metal is long and highly specialised: concentration by froth flotation, smelting and converting to a matte, leaching to remove base metals, and complex refining to separate and purify each individual PGM, demanding because the six share such similar chemistry and the end uses require extremely high purity. The whole process is energy-intensive, reagent-heavy, and often runs on electricity with a low renewable share. One environmental upside is that a single PGM supply chain typically yields a basket of valuable metals together, which is favourable in life cycle terms.
Markets and the shift from engines to hydrogen
PGM are among the most expensive metals in the world, a function of rarity, sought-after chemical properties and costly processing, prices have ranged dramatically, with rhodium reaching $20,000 per ounce in 2021 before stabilising to roughly $400–$5,000 per ounce across the group by 2024. Their classic use was in catalytic converters for internal combustion engine vehicles, which historically absorbed the large majority of supply, with smaller amounts in medical tools, dentistry, jewellery and specialty chemicals. The phase-out of petrol and diesel cars therefore posed a real challenge to the sector, but decarbonisation has opened a new demand source: hydrogen fuel cell technology, which uses PGM (particularly platinum) in electrolysers and fuel cells. At an estimated 0.1–0.5 grams of platinum per kWh of fuel cell output, and with green hydrogen and fuel cell markets projected to grow at 20–40% annually through 2030, demand for these metals has been reinvigorated, sharpening questions of criticality and placing PGM firmly on many nations' critical metals lists.
PGM are among the most expensive metals in the world, a function of rarity, sought-after chemical properties and costly processing, prices have ranged dramatically, with rhodium reaching $20,000 per ounce in 2021 before stabilising to roughly $400–$5,000 per ounce across the group by 2024. Their classic use was in catalytic converters for internal combustion engine vehicles, which historically absorbed the large majority of supply, with smaller amounts in medical tools, dentistry, jewellery and specialty chemicals. The phase-out of petrol and diesel cars therefore posed a real challenge to the sector, but decarbonisation has opened a new demand source: hydrogen fuel cell technology, which uses PGM (particularly platinum) in electrolysers and fuel cells. At an estimated 0.1–0.5 grams of platinum per kWh of fuel cell output, and with green hydrogen and fuel cell markets projected to grow at 20–40% annually through 2030, demand for these metals has been reinvigorated, sharpening questions of criticality and placing PGM firmly on many nations' critical metals lists.
Why LCA matters so much for PGM
The per-kilogram environmental impact of PGM is orders of magnitude higher than for metals like iron, nickel or even gold, because so little is extracted from the earth and the multi-stage processing needed to reach pure metal is so intensive. As a rough illustration, producing one kilogram of platinum can generate tens of thousands of kilograms of CO₂, against around ten per kilogram of nickel. That makes life cycle assessment especially powerful here: by accounting for all energy and material inputs and direct emissions across a process system, LCA reveals exactly where in the supply chain the greatest impacts arise, whether climate change from embodied greenhouse gases, particulate emissions, or acidification and eutrophication of local water. It can then guide practical decisions, switching to renewable electricity for processing (a key opportunity for South African and Russian operations) or exploring alternative reagents (particularly relevant for Canadian producers). The LCA picture for PGM remains relatively opaque, but with the EU Critical Raw Materials Act and emerging carbon footprint and product passport requirements, attention is turning to producers to measure and reduce their impacts.
The per-kilogram environmental impact of PGM is orders of magnitude higher than for metals like iron, nickel or even gold, because so little is extracted from the earth and the multi-stage processing needed to reach pure metal is so intensive. As a rough illustration, producing one kilogram of platinum can generate tens of thousands of kilograms of CO₂, against around ten per kilogram of nickel. That makes life cycle assessment especially powerful here: by accounting for all energy and material inputs and direct emissions across a process system, LCA reveals exactly where in the supply chain the greatest impacts arise, whether climate change from embodied greenhouse gases, particulate emissions, or acidification and eutrophication of local water. It can then guide practical decisions, switching to renewable electricity for processing (a key opportunity for South African and Russian operations) or exploring alternative reagents (particularly relevant for Canadian producers). The LCA picture for PGM remains relatively opaque, but with the EU Critical Raw Materials Act and emerging carbon footprint and product passport requirements, attention is turning to producers to measure and reduce their impacts.