Base metals industry

Treasury Secretary Steven Mnuchin, right, and Secretary of State Mike Pompeo, left, participate in a briefing at the White House in Washington, Friday, Jan. 10, 2020. (AP Photo/Susan Walsh)

In this photo provided by the U.N. in Papua New Guinea, members of the Bougainville Women's Federation cheer after results were announced in an independence referendum, Wednesday, Dec. 11, 2019, in Buka, Papua New Guinea. The South Pacific region of Bougainville voted overwhelmingly to become the world's newest nation by gaining independence from Papua New Guinea. (Serahphina Aupong/U.N. in PNG via AP)

This Dec. 15, 2016 photo shows a slag pile of mining waste in Anaconda, Mont. Environmental regulators have put a halt to a Montana business association’s sale of sandwich bags of mining waste advertised as a “Bag O’Slag.” Environmental Protection Agency officials overseeing the Superfund cleanup of pollution from decades of smelter operations in Anaconda came across the potentially toxic tchotchkes for sale by the city’s chamber of commerce. The slag contains small amounts of arsenic and lead. Mary Johnston, the chamber’s executive director, said Monday, Nov. 18, 2019 the EPA asked them to stop selling the black slag in a re-sealable bag and gave them some alternatives. (AP Photo/Matt Volz)

FILE - In this Dec. 8, 2013 file photo, steel beams sit outside Arena de Sao Paulo in Sao Paulo, Brazil. President Donald Trump on Dec. 2, 2019 accused Brazil and Argentina of hurting American farmers through currency manipulation and said he’ll slap tariffs on their steel and aluminum imports to retaliate. (AP Photo/Ferdinand Ostrop, File)

President Donald Trump listens during an event to sign an executive order establishing the Task Force on Missing and Murdered American Indians and Alaska Natives, in the Oval Office of the White House, Tuesday, Nov. 26, 2019, in Washington. (AP Photo/ Evan Vucci)

FILE - In this July 22, 2015 file photo, Tribal councilman Wendsler Nosie Sr. speaks with Apache activists in a rally to save Oak Flat, land near Superior, Ariz., sacred to Western Apache tribes, in front of the U.S. Capitol in Washington. Nosie is drawn to a mountainous area in central Arizona where he and other Apaches have harvested medicinal plants, held coming-of-age ceremonies and gathered acorns for generations. On Thursday, Nov. 28, 2019, he'll start a three-day journey to make a permanent home at Chi’chil Bildagoteel, or Oak Flat, in protest of a copper mine made possible by a federal land exchange. (AP Photo/Molly Riley, File)

In this picture taken Friday, Aug. 17, 2012, Italy's largest steel plant is seen in Taranto, Italy. Italian Premier Giuseppe Conte says steelmaker ArcelorMittal has agreed to try for a negotiated solution over the fate of a southern Italian steel plant. Conte and his economy and economic development ministers held four-hour talks ending Friday before midnight with ArcelorMittal’s top executives. Union leaders on Saturday insisted that any deal must exclude layoffs. (AP Photo/Paola Barisani)