Refining and Metallurgy of Critical Minerals
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Refining turns concentrates and intermediates into the metals and chemicals that industry buys, using heat (pyrometallurgy), chemical solutions (hydrometallurgy) or electricity (electrometallurgy). The United States has gaps at this stage for many critical minerals. The US Geological Survey reports that the last US primary nickel refinery closed in 1985, that no primary gallium has been recovered since 1987, that tungsten has not been mined since 2015, and that the last domestic titanium sponge plant closed in 2024.
1985
year the last US primary nickel refinery (Port Nickel, Louisiana) ceased operating
1987
last year primary low-purity gallium was recovered in the US
8,900 t
US production of rare earth compounds and metals in 2025, up from 120 t in 2021
What can the United States refine today?
The table covers eleven minerals and says, from the USGS 2026 summaries, what is mined and what is refined or processed domestically. The answer ranges from a full domestic by-product chain for rhenium to none for titanium sponge.
| Mineral | Mined in the US? | Refined or processed in the US? |
|---|---|---|
| Nickel | Eagle Mine, Michigan, about 10,000 t of nickel in concentrate, exported to smelters in Canada and overseas (USGS) | No primary refinery since 1985; three refinery projects are under consideration in Missouri, Oklahoma and Texas and a pilot facility was built in Oklahoma |
| Cobalt | Eagle Mine produces cobalt-bearing nickel concentrate (USGS) | About five companies produce cobalt chemicals; most supply is imports and scrap |
| Lithium | A continental brine operation in Nevada (USGS) | Two companies make downstream compounds from domestic or imported carbonate, chloride and hydroxide |
| Graphite | None; the last natural graphite was mined in 1979 (USGS) | Spherical purified graphite is made by two companies in Illinois and Louisiana; at least eight others are considering plants |
| Rare earths | Mountain Pass, California: 51,000 t of oxide in concentrate (USGS) | Compounds and metals output rose to 8,900 t in 2025; net import reliance for compounds and metals is 67% |
| Gallium | None (USGS) | One New York company refines high-purity gallium from imported low-purity metal and new scrap |
| Germanium | Zinc concentrates containing germanium from a mine in Alaska (USGS) | Concentrates are sent to a refinery in Canada; a Utah company makes wafers and an Oklahoma company makes germanium tetrachloride from imported and recycled material |
| Tungsten | None since 2015 (USGS) | Seven companies convert concentrates and scrap into powders, carbides and chemicals |
| Titanium | Not applicable (USGS) | No titanium sponge produced in 2025; plants in Nevada and Utah are idle |
| Indium | Not recovered from ores (USGS) | Several companies make alloys, compounds and solders from imported indium metal |
| Rhenium | By-product of molybdenum concentrates from copper-molybdenum mines in Arizona and Montana (USGS) | Primary production of about 9,800 kg in 2025; the US is a leading producer of secondary rhenium |
What are the three refining routes?
The routes are named for the energy or reagent they use, and the sources give an example of each. Pyrometallurgy uses heat: rhenium is recovered by roasting molybdenum concentrates. Hydrometallurgy uses chemical solutions: Lynas cracks and leaches rare earth feed in Malaysia, and the USGS notes that recyclers recover rhenium and other metals hydrometallurgically from superalloy scrap. Electrometallurgy uses electricity: the USGS describes cobalt cathode as refined cobalt metal produced by an electrolytic process. Most critical minerals pass through more than one route. For rare earths the chemistry is on the separation page.
Where is refining concentrated?
Refining is concentrated in China for many of the minerals above. The USGS reports that China produced 99% of primary low-purity gallium, leads refined cobalt production and is the leading producer of germanium. The International Energy Agency found that the top three refiners held an average 86% share across copper, lithium, nickel, cobalt, graphite and rare earths in 2024. Outside China, projects to refine rare earths, gallium and germanium are described on the separation capacity and semiconductors pages, and the reasons are on why China dominates processing.
Frequently asked questions
What is the difference between pyrometallurgy, hydrometallurgy and electrometallurgy?
Pyrometallurgy uses heat to extract metals, hydrometallurgy uses chemical solutions to leach and purify them, and electrometallurgy uses electricity to deposit or refine them. Rhenium is recovered by roasting, rare earths by acid leaching and solvent extraction, and cobalt cathode by electrolysis.
Does the United States have a nickel refinery?
The United States has had no primary nickel refinery since the Port Nickel facility in Louisiana ceased operations in 1985, according to the USGS. Three refinery projects are under consideration in Missouri, Oklahoma and Texas, and a pilot facility was built in Oklahoma.
Does the US produce gallium?
The US has not recovered primary gallium since 1987. One company in New York refines high-purity gallium from imported low-purity metal and new scrap, and US net import reliance is 100%.
Which country dominates critical mineral refining?
China dominates refining of many critical minerals. The USGS reports that China produced 99% of primary low-purity gallium and leads refined cobalt production, and the IEA says the top three refiners held an average 86% share across six key minerals in 2024.
Sources
Read on October 12, 2026. Figures on this page come from these documents; where a number is an estimate, the source says so.
- USGS Mineral Commodity Summaries 2026: Nickel, cobalt, lithium, graphite, rare earths, gallium, germanium, tungsten, titanium, indium, rhenium
- IEA: Diversification is the cornerstone of energy security (May 2025)
- Lynas Rare Earths: 2026 Annual Report and Appendix 4E (26 August 2026). Read on 14 October 2026
