Nickel and cobalt from U.S. mines and refineries: Assessment of five dimensions of mineral availability

Federal policies in the United States (U.S.) are aimed at increasing domestic mining and refining of critical minerals such as nickel (Ni) and cobalt (Co). These two metals are key components in lithium-ion NMC batteries common in electric vehicles. This paper examines active and proposed Ni and Co mining and refining projects in the U.S. to evaluate five dimensions of mineral availability: 1) Geological, 2) Technical, 3) Economic, 4) Political, and 5) Social and Environmental. Only very small amounts of Ni and Co have been mined in the U.S. in recent decades. Despite significant geological resources of Ni and Co in the U.S., the only Ni mining is at Eagle, Michigan, which produces a nickel concentrate that is refined in Canada. There is no U.S. Co production, and recent Co mine construction in Idaho has halted due to market pricing. Proposals for new Ni mines have met with social opposition and regulatory complexity at Maturi, NorthMet, and Mesaba in Minnesota based on environmental concerns. Domestic refining is limited to minor byproduct recovery of Ni and Co from Stillwater ores at the Columbus refinery, Montana. Refineries have been proposed or are under construction in Missouri, Idaho, and Minnesota. Despite the geological availability of U.S. Ni and Co, the majority of these resources have not yet been demonstrated as viable from the technical, economic, political, social and environmental dimensions.