A company backed by Stellantis and General Motors is launching an initiative to manufacture magnets without rare-earths elements, in an effort to help the US sidestep China's dominance over critical minerals.

If successful, the company, Niron Magnetics, would be the first to manufacture magnets without relying on rare earths that have been a crucial industry component for more than half a century. Niron is building a 1,500-tonne factory in Sartell, Minnesota, which it says could satisfy 3 per cent of US magnet demand.

Niron's technology relies on research by co-founder Jian-Ping Wang, a professor at the University of Minnesota, who discovered the magnetic properties of iron nitride, a compound formed from the combination of iron and nitrogen -- two of the most abundant elements in the earth's crust and atmosphere. It said the new compound is 18 per cent more powerful than other magnetic compounds.

Magnets are important components in defence, automotive, medical and entertainment technologies, and have become indispensable due to their growing use in manufacturing. They typically rely on rare earths such as neodymium, terbium and praseodymium for their magnetic properties. China's dominance over supplies is a source of anxiety for industry and Washington. The leading manufacturers of magnets are largely concentrated in China, although Japanese companies such as Hitachi have a foothold.

Still, the company is facing questions about how its designs will work without rare earths.

"This is a holy grail kind of magnet, since iron and nitrogen are plentiful and low cost," said John Ormerod, a rare earths consultant at JOC LLC. Still, "We don't have any data from Niron, which is frustrating and makes it impossible to make a hundred per cent accurate assessment."

While the Trump administration has invested directly in mining and magnet production -- becoming the largest shareholder in MP Materials, operator of the Mountain Pass mine in California -- Niron says its technology bypasses some of the need to bring rare earth supply chain to the US.

"Western rare earth companies are playing the Chinese at the same game," said Niron chief executive Jonathan Rowntree. "We don't need to bring a mine online."

However, questions linger over the feasibility of its technology replacing rare earth magnets.

While Niron's move towards commercialisation is a "good signal", according to Milo McBride, a fellow in the Sustainability, Climate, and Geopolitics programme at the Carnegie Endowment for International Peace, the end use for their products has yet to be determined.

"The magnet market covers everything from consumer electronics to military hardware," he said. "The smaller end consumer market will probably be first, but since the US has such a large magnet supply deficit, there's no reason to not try."

Niron has received $150mn in funding from Stellantis, as well as the venture capital arms of GM, Volvo Cars and Samsung. In January it received a $52.2mn tax credit from the energy and Treasury departments, as well as $17.5mn from the energy department's research and development agency in 2022. The plant will be operational by early 2027.

Demand for magnets is surging, with a projected shortfall of 55,000 tonnes by 2030.

"Permanent magnets are in every device that powers the modern world," said Mark Champine, head of North America technical centre for Stellantis. "Niron is meeting an urgent demand."

US magnet start-up targets China's grip on rare earths