The country’s largest magnesium supplier shut down. Now what?

Only a few years ago, if you popped open a can of soda anywhere in the United States, the container you held more likely than not contained bits of magnesium harvested from the Great Salt Lake.

Now, the country’s supply of the critical mineral looks uncertain. The largest producer, US Magnesium, filed for bankruptcy in September. Its half-century-old Rowley smelting plant on the west shore of Utah’s famed lake could shutter for good.

The news comes as a relief for many environmental and Great Salt Lake advocates, but it also stokes broader anxieties over the supply chain for a material used in all kinds of products from car parts to wind turbines to solar-panel scaffolding and missiles.

“If we remove any [magnesium production] capacity we have here, that means that we’re wholly dependent, essentially, on imports,” said Simon Jowitt, Nevada’s state geologist and the director of the Nevada Bureau of Mines and Geology.

Other industry insiders say losing US Magnesium isn’t necessarily a cause for alarm.

“They haven’t been producing, really, for about three years,” said John Haack, president of Tennessee-based MagPro LLC, a magnesium metal recycling company. “The marketplace has pretty much adjusted.”

Commercial magnesium comes from evaporating salty brine or seawater, mining dolomite rock, or recycling scrap metal. Until its production plant shut down in late 2021 due to equipment failures, US Magnesium asserted that it was the largest source of primary, non-recycled magnesium in North America.

“There is no other significant producer of primary magnesium in the United States,” said Ron Thayer, the company’s president, in a sworn declaration filed in federal bankruptcy court on September 10, “and primary magnesium is a critical component to United States defense contractors.” It will take a $40 million investment for magnesium production to resume at the Rowley plant, Thayer later testified in a deposition.

Just how much magnesium the company produced each year before it shut down is a carefully guarded trade secret. The U.S. Geological Survey reported this year, however, that the United States has the capacity to produce 64,000 metric tons of primary magnesium metal, compared to China’s 1.8 million tons.

The magnesium market experienced some hiccups when US Magnesium mothballed its plant. In 2022, prices for the mineral doubled in some regions, and a factory that produced aluminum cans in Indiana temporarily shut down because of US Magnesium’s lack of production, according to the USGS. But by 2023, companies had found alternative magnesium providers and prices began to fall.

The federal agency’s reports cited MagPro as a source of secondary domestic magnesium, which it produces from recycling. But Haack said his company produces primary magnesium as well, mostly for alloy products. He said his company is prepared to ramp up production to meet demand.

“We haven’t really advertised [it] as much,” Haack said. “But we definitely produce primary, and we’re excited to expand more into the marketplace.”

The federal government doesn’t appear to be taking any chances on the dip in domestic magnesium production, however. And while the current market might have adjusted to US Magnesium’s mothballing, experts worry about what the future — and foreign competition — might hold. Especially because magnesium is used in so many products.

“It may not make things more expensive initially,” Jowitt said, “but certainly in the long term, it would mean that China would control the price of magnesium for anybody in the U.S. who wants to use it.”

The U.S. Department of Defense awarded a $19.6 million grant to a Bay Area startup, Magrathea Metals Inc., in 2023, just two years after US Magnesium’s production plant shut down, to “establish domestic production of magnesium.” Jowitt pointed to the investment as a sign the federal government views a slowdown in production of the metal as a national security risk.

Magrathea, which is scouting Utah as a potential site for a pilot demonstrating its technology, currently produces magnesium metal from seawater salt.

Alex Grant, a chemical engineer and Magrathea’s founder, said his company aims to replace the production lost by US Magnesium’s closure by the end of the decade. The biggest challenge, he said, is finding a local workforce that understands the production process.

“Building these large capital projects,” Grant said, “it’s a muscle that the U.S. has lost because we didn’t flex it enough.”

The United States needs to continue producing and investing in domestic magnesium production, Grant added, if it wants to avoid crippling geopolitical consequences. That’s especially the case if China implements an export control — a type of tariff, ban or forced licensing — on the material, like it recently did for several rare-earth minerals. “Putting an export control on magnesium would provoke a war, plain and simple,” Grant said.

Thayer, US Magnesium’s president, declined to answer questions about potentially losing market share to MagPro or Magrathea. But he disagreed with the assertion that the market has adjusted to his plant’s lack of production.

“The suspended … production of magnesium has been replaced by Chinese/foreign imports,” Thayer wrote in an email, “not additional U.S.-based volume. Not ideal for U.S. supply chain independence.”

The federal government took measures over the years to protect US Magnesium in order to keep its plant in business and a national supply of a critical mineral flowing. The Department of Commerce approved antidumping measures against magnesium from China starting in 1995, although it declined to adopt similar duties against Israel — which produces magnesium from Dead Sea salts — in 2019.

Still, US Magnesium partly blamed foreign competition for its bankruptcies filed in 2001 and September of this year.

Utah has long grappled with the environmental toll of the US Magnesium plant, which polluted the air along the Wasatch Front, Utah’s urban core, and contaminated land and groundwater near the Great Salt Lake.

“It may be that [building] a newer plant, especially supported by the federal government, is a better way forward than trying to get something that’s problematic up and running again,” Jowitt said.

In Utah, royalties from US Magnesium’s mineral sales funneled just under $1 million each year over the past five years to the state, officials confirmed.

Still, state resource managers have moved to revoke the company’s mineral lease and shut down its operations for good. The Division of Forestry, Fire, and State Lands cited unauthorized storage of hazardous waste on and around the bed of the Great Salt Lake as grounds for the lease revocation, among other violations. State regulatory actions are on pause as the company works through its current bankruptcy proceedings.

“Historically, US Mag has always been a challenge to work with,” said Lynn de Freitas, executive director of Friends of Great Salt Lake, an environmental advocacy and watchdog group. “There’s a hell of a lot to clean up and address.”

Efforts to manage US Magnesium’s Superfund status and shore up waste ponds under a consent decree with the Environmental Protection Agency appear in limbo as well. It also isn’t clear what the permanent closure of the plant would mean for the Wasatch Front’s air.

A widely publicized 2023 report by the National Oceanic and Atmospheric Administration found that US Magnesium contributed up to 25 percent of the Wasatch Front’s wintertime particulate smog. Governor Spencer Cox, a Republican, asked the Environmental Protection Agency soon after to include the plant as a reason the region was not in compliance with the Clean Air Act. But US Magnesium’s plant had been switched off for more than two years by the time the report was published.

Thayer denied magnesium production had any impact on the region’s smog in emailed statements. He added that inversion pollution stayed the same after the plant shut down in late 2021.

The EPA removed Utah’s Wasatch Front from its dirty air list for wintertime inversion smog last month. It’s the first time the region found itself in compliance with Clean Air Act standards in 15 years.

In an email, Carrie Womack, a NOAA scientist and lead author of the US Magnesium pollution study, said the findings were based on modeling a single pollution event in 2017. Figuring out the impact of US Magnesium’s shutdown on Utah’s air would require modeling multiple years, Womack said. “Wintertime pollution has a lot of factors, only one of which is anthropogenic [human-caused] emissions,” she wrote.

Regardless, magnesium production doesn’t necessarily have to take a heavy environmental toll, said Grant, Magrathea’s founder.

“Everything US Mag did on the environmental front that was a problem, was a choice,” Grant said. “And they did it that way because they’re owned by a firm that does not care about anything besides making as much money as possible.”

This story was originally published by Grist with the headline The country’s largest magnesium supplier shut down. Now what? on Dec 23, 2025.