Base metals industry

Pura Castell walks to a government-run butcher shop to buy chicken, after failing to find chicken the previous day in Bauta, Cuba, Friday, April 12, 2019. A neighbor informed her that chicken had arrived at the government store that distributes almost free monthly food rations. (AP Photo/Ramon Espinosa)

File-This Aug. 22, 2018, file photo shows a sign declaring the future home of Braidy Industries' aluminum mill in Ashland, Ky. An aluminum company planning to build a $1.7 billion plant in Appalachia is forming a partnership with a Russian company that until recently faced U.S. sanctions. Russian aluminum giant Rusal wants to invest $200 million in an aluminum rolling mill that Braidy Industries intends to build near Ashland, Kentucky. Rusal says it would assume a 40 percent ownership share in the mill in return for the investment. Braidy Industries would hold the other 60 percent share. (AP Photo/Adam Beam, File)

FILE - In this Feb. 10, 2016, file photo, the closed LTV Steel taconite plant is abandoned near Hoyt Lakes, Minn. The Army Corps of Engineers has awarded the planned PolyMet copper-nickel mine in northeastern Minnesota the final permit it needs to proceed. The permit deals with how PolyMet will mitigate its effects on wetlands. PolyMet calls it a "historic achievement" that will let it move forward with Minnesota's first copper-nickel mine. Minnesota regulators issued the other key permits for the project last year, but the mine still faces court challenges. (AP Photo/Jim Mone, File)

An island of solar panels floats in a pond at the Los Bronces mining plant, about 65 kilometers (approximately 40 miles) from Santiago, Chile, Thursday, March 14, 2019. The island of solar panels could give purpose to mine refuse in Chile by using them to generate clean energy and reduce water evaporation.(AP Photo / Esteban Felix)

In this Monday, March 4, 2019, photo, U.S. Secretary of State Mike Pompeo speaks to the Future Farmers of America and Johnston High School students in Johnston, Iowa. President Donald Trump’s willingness to engage in international trade fights has set off volleys of retaliatory tariffs that are driving down the price of pork, corn and soybeans in Iowa and elsewhere. Pompeo sought to calm some of those nerves Monday even as he warned that Chinese theft of technology affects agriculture, too. “The good news is this _ help is on the way,” Pompeo said. (AP Photo/Charlie Neibergall)

An aerial view shows a collapsed bridge caused by flooding triggered by a dam collapse near Brumadinho, Brazil, Friday, Jan. 25, 2019. The dam that held back mining waste collapsed, inundating a nearby community in reddish-brown sludge, killing at least seven people and leaving scores of others missing. (Bruno Correia/Nitro via AP)

Friends and relatives attend the burial of Vale SA employee Edgar Carvalho Santos, victim of the collapsed dam in Brumadinho, Brazil, Tuesday, Jan. 29, 2019. Officials said the death toll was expected to grow "exponentially," since no had been rescued alive since Saturday. (AP Photo/Andre Penner)