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Industry Primers

Bottom-up NAICS industry primers written for both public-market and private investors. Leaf industries are researched from the ground up; every group, subsector, and sector above them reads as a contrast across the industries beneath it.

2122 industries · 24 sectors · NAICS 2022

Researched with AI assistance from official U.S. statistics and independent sources, with citations on every page. Figures are not individually verified against pinned evidence — primers marked Evidence-verified are. Industry research, not investment advice. Methodology.

IndustryNAICS 33141

U.S. Nonferrous Metal (except Aluminum) Smelting and Refining — NAICS 33141

1. Overview

North American Industry Classification System (NAICS) code 33141 covers U.S. establishments that smelt ores or refine nonferrous metals other than aluminum — copper, zinc, antimony, beryllium and precious or specialty metals.[1] A smelter uses heat or chemistry to separate metal from ore concentrate; a refinery then raises purity, often by electrolysis.

This is a five-digit NAICS industry that contains a single six-digit child industry, 331410. Because there is exactly one child, this level and its child describe the same activities, the same plants and the same companies. This page gives the ground-truth federal statistics published at the 33141 level and then points you to the 331410 primer for the full treatment of structure, companies, economics and risk.

2. What's inside — and why the level equals its one child

NAICS 33141 rolls up to just one industry:

Child code Name What it is
331410 Nonferrous Metal (except Aluminum) Smelting and Refining Primary smelting of nonferrous ores and primary refining of nonferrous metals other than aluminum.[1]

With a single child, the rollup adds no breadth — 33141 is 331410. The reason to read this page rather than the child page is that three federal series are published at the five-digit level and are not carried in the child primer: the Economic Census receipts, firm count and concentration ratios in Section 3; the Federal Reserve's industrial-production index; and the Bureau of Labor Statistics injury rate. Everything qualitative (feed security, treatment charges, by-product credits, environmental liability) is identical; see the 331410 primer for that detail.

Neighboring activities sit in different codes and are excluded here: mining, concentration and mine-site electrowinning (NAICS 2122), aluminum production (331313), copper scrap recovery, alloying and rolling (331420), secondary recovery of other nonferrous metals from scrap (331492), downstream rolling and extrusion (331491), and scrap sorting without smelting (423930 or 562920).[1] These exclusions are not academic: several of the most visible recent investments in U.S. nonferrous processing are recycling projects that may fall outside 331410 entirely.

3. Size (rollup figures)

Two federal sources describe this level. County Business Patterns (CBP) counts employer establishments and jobs; the Economic Census, taken every five years, adds receipts, firm counts and concentration.

Metric Federal figure Source (vintage)
Employer establishments 112 CBP 2023[2]
Employment 8,755 CBP 2023[2]
First-quarter payroll $190.738 million CBP 2023[2]
Annual payroll $743.431 million CBP 2023[2]
Firms 81 Economic Census 2022[3]
Receipts (shipments) $12.286 billion Economic Census 2022[3]

Concentration. The Economic Census also reports how much of the industry's receipts flow to its largest firms. The share held by the four largest firms (the CR4, or four-firm concentration ratio) was 56.3%; the eight largest held 68.3%; the twenty largest, 86.6%; the fifty largest, 99%. The Herfindahl-Hirschman Index (HHI) — the sum of every firm's squared market share, where higher means more concentrated — was 881.9.[3] Read together, these say a handful of firms do most of the smelting while a long tail of small specialty refiners fills out the count. The physical asset base is narrower still than the firm count implies: in 2025 the United States operated two primary copper smelters and two primary electrolytic copper refineries, with estimated primary refined-copper output of 790,000 metric tons,[4] plus one primary zinc smelter[5] and one operating antimony smelter.[6] Note that mine-site electrowinning plants counted in commodity totals do not necessarily belong in this industry.[4]

Where the receipts figures disagree. The revised child primer does not restate the Economic Census receipts, firm count or concentration ratios — it reports that no usable ingested federal figure was available for them — and instead offers a different anchor: an EPA rulemaking memorandum reproducing Census Annual Survey of Manufactures data puts 2021 shipments and service receipts for NAICS 331410 at $15.905 billion.[7] That is roughly $3.6 billion above the 2022 Economic Census figure for the same activity. The two are not directly comparable — different survey programs, different coverage and different years, across a period of volatile metal prices — and neither should be treated as a correction of the other. Use the Economic Census figure when you want the concentration ratios that come with it, and treat the ASM figure as a separate reading of the same industry.

Undercount caveat. These are employer-establishment and firm statistics, not a census of furnaces. CBP excludes the self-employed, non-employer businesses and most government units, and the Census Bureau adds statistical noise to protect individual companies. That undercount matters less here than in industries dominated by tiny or individually owned operators, because primary smelting is capital-intensive and concentrated — but where a metal is refined by a single family-owned firm, a suppressed cell can hide it. No suppressed value is stated above. For a fresher output signal, the Federal Reserve's industrial-production index for NAICS 33141 read 76.6 in June 2026 (2017 = 100); it tracks output direction, not capacity use.[8] One more five-digit series worth knowing: the Bureau of Labor Statistics reported a total recordable injury-and-illness incidence rate of 4.1 cases per 100 full-time-equivalent workers for 33141 in 2022.[9]

4. Investable universe (where value concentrates)

Because the level equals its one child, the investable map is the child's map. Value concentrates in a few places:

  • Integrated copper, embedded inside much larger diversified miners. This is where the level's economics are most concentrated: Freeport-McMoRan stated in early 2026 that its integrated domestic facilities supply approximately 70% of total U.S. refined copper production,[10] and Rio Tinto's Kennecott complex in Utah is the other integrated smelter-refinery.[11] In both cases U.S. smelting and refining is a small slice of a mine-to-metal business.
  • Specialty metals, the cleaner listed exposures — beryllium (Materion, whose Utah mine and mill feed primary production in Ohio)[12] and antimony (United States Antimony's Thompson Falls, Montana, smelter)[6] — where the U.S. plant is central to the company but downstream engineered products often dominate revenue, or where scale is small and execution risk high.
  • Foreign-listed smelter owners, notably Korea Zinc, which has owned the country's sole primary zinc smelter at Clarksville, Tennessee, since April 2026.[5]
  • Brownfield-restart optionality, principally Grupo México's privately held Asarco subsidiary, which owns the idle Hayden smelter and Amarillo refinery — potential capacity rather than current operating exposure.[13]
  • Privately held refiners and traders, which own or feed individual plants (precious-metal refining, feed supply and offtake), plus recycling-adjacent processors such as Aurubis, whose Richmond, Georgia, multimetal project began commissioning in September 2025 but may fall outside strict NAICS 331410 classification.[14]

Specific tickers, listings and exposure quality are laid out in Section 4 of the 331410 primer. The concentration figures in Section 3 above explain why the list is short: the top four firms alone account for more than half of receipts.[3] The counterpart caution is classification — company filings blend mining, primary refining, recycling and fabrication, so a listed name's reported segments rarely isolate the activity this code describes.

5. How the money works

Three revenue models coexist, unchanged at this level: integrated mine-to-metal (capture the metal price less all processing and freight cost); toll or merchant smelting (earn treatment and refining charges, or TC/RC, plus metal recoveries and by-products); and specialty refining (earn on purity, difficult metallurgy and qualified customer contracts). By-product credits — sulfuric acid, gold, silver, selenium, tellurium, germanium, gallium — can materially cut net processing cost, and can be strategic rather than incidental: Freeport describes its Miami smelter as the most significant source of sulfuric acid for its U.S. leaching operations, which is why an integrated smelter can be worth running even when stand-alone conversion margins are weak.[15]

The industry's central paradox is that scarce concentrate can hurt smelters, because miners pay lower treatment and refining charges when many smelters compete for limited feed. The 2025 annual copper treatment-charge benchmark was $21.25 per metric ton with a refining charge of 2.125 cents per pound, and some 2025 contracts were subsequently agreed at no processing fee amid concentrate scarcity.[16] Integrated U.S. plants are less exposed to that squeeze because their own mines supply them.[15]

Two further points shape reported earnings at this level. Maintenance is lumpy: Freeport's 2025 major Miami turnaround generated $73 million of maintenance and idle-facility costs, and management expects such turnarounds roughly every three to four years.[15] And price does not translate cleanly into domestic volume: the annual-average U.S. producer cathode price moved from 395.3 cents per pound in 2023 to 431.8 cents in 2024 and an estimated 490 cents in 2025, while primary U.S. refinery production went 843,000, then 882,000, then an estimated 790,000 metric tons over the same years.[4] See Section 5 of the child primer for the full mechanics and the operating metrics worth tracking.

6. Demand drivers

Copper is the largest visible demand engine — U.S. copper and copper-alloy use in 2025 was led by building construction (42%), electrical and electronic products (23%), transportation (18%), consumer and general products (10%) and industrial machinery (7%).[4] Zinc (galvanizing), beryllium (aerospace, defense and advanced nuclear), antimony (flame retardants, ammunition, energy storage) and precious/specialty metals (electronics, catalysts, medical, defense) round out demand. Construction, autos and capital goods make the industry cyclical.

Electrification adds a secular layer. The International Energy Agency projects global clean-technology copper demand rising from 7.737 million metric tons in 2024 to 10.910 million in 2030, with total demand rising from 26.717 million to 31.348 million metric tons,[17] and judges that copper supply could fall 30% short of demand by 2035.[18] Read those as findings about the global mine market, not a forecast of U.S. smelter margins — a concentrate shortage helps miners and can hurt processors.

Two structural counterweights matter at this level. Recycling supplied roughly 30% of U.S. copper supply in 2025, with an estimated 160,000 metric tons recovered from old scrap and 760,000 metric tons from new manufacturing scrap;[4] it displaces some primary demand while creating investable refining capacity, though much of that activity is classified in 331420 rather than here. And supply-chain policy is now a capital-allocation driver: copper was added to the U.S. critical-minerals list in 2025,[19] while refined-copper net import reliance reached an estimated 57% of apparent consumption in 2025, with Chile supplying 68% of refined imports during 2021–24.[4] That argues for domestic processing investment, but projects still face feed, energy, permitting and construction constraints.

7. Regulation

Primary smelting combines high heat with sulfur, arsenic, lead and beryllium, so regulation reaches air, water, waste, worker exposure and legacy contamination. The U.S. Environmental Protection Agency (EPA) regulates primary copper smelters under the Clean Air Act's National Emission Standards for Hazardous Air Pollutants (NESHAP), amended in 2024.[20] A 2025 presidential proclamation then extended compliance deadlines by two years for specified sources, noting explicitly that only two primary copper smelters were operating nationally.[21] Relief of that kind preserves capacity, but leaves investors exposed to changing administrations, litigation, state requirements and potentially large deferred retrofit costs.

Process wastewater is covered by the Nonferrous Metals Manufacturing Effluent Guidelines at 40 CFR Part 421.[22] Under the Resource Conservation and Recovery Act (RCRA), only 20 specified high-volume, lower-hazard mineral-processing wastes receive the Bevill exclusion; other hazardous smelting wastes remain subject to hazardous-waste and land-disposal rules.[23] The Occupational Safety and Health Administration (OSHA) separately sets exposure limits for lead, arsenic and beryllium[24] — and the 4.1-per-100 injury rate in Section 3 is the measurable outcome of that exposure profile.[9] State permits, cleanup obligations and community opposition can bite as hard as federal rules.

Trade policy is now a live variable. A 50% Section 232 tariff on covered semi-finished copper and intensive derivative imports took effect on August 1, 2025,[25] and an April 2026 proclamation changed covered-metal tariffs to apply to the product's full customs value.[26] Do not assume refined cathode, concentrate and the rest of this code's product set receive the same protection as downstream rod, tube or wire. Full detail is in Section 7 of the 331410 primer.

8. Consolidation

Barriers to entry are formidable — multibillion-dollar replacement costs, specialized labor, long permitting, reliable power, rail or port access, acid markets and secure concentrate feed — which is why the operating base is so narrow and the concentration ratios in Section 3 so high. Scarcity does not guarantee margin, however, because global concentrate markets still set TC/RC. Recent moves reinforce the strategic value of existing sites:

  • Korea Zinc has presented a $7.4 billion phased multi-metal project at Clarksville extending into early 2030 — a forward-looking construction plan, not current capacity.[27][5]
  • Grupo México is doing technical work on restarting and modernizing Hayden and Amarillo; outcome, timing and economics remain uncertain.[28]
  • Materion and United States Antimony are expanding specialty-metal capacity, supported partly by defense-related demand and funding.[12][6]
  • Aurubis began commissioning its Richmond, Georgia, multimetal recycling project in September 2025, expecting roughly 180,000 metric tons of complex recycling material annually once both phases ramp.[14]

These are covered in Section 8 of the child primer.

9. Risks

The risk set is the child's: feed risk (concentrate shortages depress utilization and treatment charges), commodity risk, operational outages (refractory, furnace, acid-plant and electrical failures), environmental liability that can outlast the asset, capital intensity (restarts becoming full rebuilds), energy and logistics cost, working-capital swings on purchased metal, project risk on announced capacity, regulatory and trade risk (tariff coverage, compliance deadlines and permitting all shift with administrations and litigation), and classification risk — company filings routinely blend mining, primary refining, recycling and fabrication, so reported segments rarely isolate NAICS 331410 (or 33141). See Section 9 of the 331410 primer.

10. How to invest & outlook

Because 33141 equals 331410, the how-to-invest guidance is identical — separate metal-price exposure from processing exposure, value integrated copper economics apart from specialty-material, foreign-listed and development-stage plays, and, for private investors, diligence feed contracts, minimum-volume commitments, power arrangements, environmental indemnities, restart capital and by-product sales before crediting any announced capacity. Replacement cost means little until you deduct remediation and modernization. Useful public-market yardsticks (enterprise value to earnings before interest, taxes, depreciation and amortization, or EV/EBITDA; free-cash-flow yield; return on invested capital) should be tested at normalized metal prices and normalized maintenance spending, given how lumpy turnarounds are.

Outlook. Long-run demand from electrification, grid investment, defense and secure domestic supply chains is favorable, but near-term processing economics are less straightforward because tight concentrate supply can depress smelter charges. Integrated plants with captive feed and strong by-product recovery look better positioned than standalone merchant smelters; brownfield restarts and government-backed projects offer upside, but their announced capacity deserves little value until permits, financing and construction milestones are secured. For the complete company-level analysis, valuation and outlook, read the 331410 primer — this page exists to record the federal statistics published at the five-digit rollup and to flag where they diverge from the child's sources.

Sources

  1. U.S. Census Bureau, "2022 NAICS Definition: 331410 Nonferrous Metal (except Aluminum) Smelting and Refining," 2022, https://www.census.gov/naics/?details=331410&input=331410&year=2022
  2. U.S. Census Bureau, "All Sectors: County Business Patterns, 2023," 2025, https://data.census.gov/table/CBP2023.CB2300CBP
  3. U.S. Census Bureau, "Economic Census 2022: Concentration by Largest Firms (NAICS 33141)," 2025, https://www.census.gov/programs-surveys/economic-census.html
  4. U.S. Geological Survey, "Mineral Commodity Summaries 2026," 2026, https://pubs.usgs.gov/periodicals/mcs2026/mcs2026.pdf
  5. Nyrstar, "Nyrstar Completes Sale of Its U.S. Assets to Korea Zinc," 2026, https://www.nyrstar.com/resource-center/press-releases/nyrstar-completes-sale-of-its-us-assets-to-korea-zinc
  6. United States Antimony Corporation, "Form 10-K for the Year Ended December 31, 2025," 2026, https://www.sec.gov/Archives/edgar/data/101538/000110465926032049/uamy-20251231x10k.htm
  7. U.S. Environmental Protection Agency, "Primary Copper Smelting: Background Document for Proposed Amendments," 2024, https://downloads.regulations.gov/EPA-HQ-OAR-2020-0430-0240/attachment_53.pdf
  8. Board of Governors of the Federal Reserve System, "Industrial Production and Capacity Utilization—Table 1C," 2026, https://www.federalreserve.gov/releases/g17/current/table1c_sup.htm
  9. Bureau of Labor Statistics, "Injury and Illness Rates by Industry, 2022," 2023, https://www.bls.gov/iif/nonfatal-injuries-and-illnesses-tables/table-1-injury-and-illness-rates-by-industry-2022-national.htm
  10. Freeport-McMoRan, "Form 10-Q for the Quarter Ended March 31, 2026," 2026, https://www.sec.gov/Archives/edgar/data/831259/000083125926000025/fcx-20260331.htm
  11. Rio Tinto, "Annual Report 2025," 2026, https://www.sec.gov/Archives/edgar/data/863064/000162828026009531/rio-20251231.htm
  12. Materion Corporation, "Form 10-K for the Year Ended December 31, 2025," 2026, https://www.sec.gov/Archives/edgar/data/1104657/000110465726000011/mtrn-20251231.htm
  13. Grupo México, "Annual Report 2024," 2025, https://www.gmexico.com/GMDocs/ReportesFinancieros/ING/2024/RF_EN_2024_IFN.pdf
  14. Aurubis, "Annual Report 2024/25," 2025, https://www.aurubis.com/dam/jcr%3Af6546e7e-fbe9-4eaf-bb41-81f276e14438/Aurubis_Annual%20Report_FY%202024_25.pdf
  15. Freeport-McMoRan, "Form 10-K for the Year Ended December 31, 2025," 2026, https://www.sec.gov/Archives/edgar/data/831259/000083125926000012/fcx-20251231.htm
  16. Reuters, "China's Copper Smelters Win Better Terms as Concentrate Tightens," 2025, https://finance.yahoo.com/news/chinas-copper-smelters-win-better-052000916.html
  17. International Energy Agency, "Global Critical Minerals Outlook—Copper," 2025, https://www.iea.org/reports/copper-2
  18. International Energy Agency, "Copper Prices Have Hit Record Highs, but Smelters Face Mounting Strategic Pressures," 2025, https://www.iea.org/commentaries/copper-prices-have-hit-record-highs-but-smelters-face-mounting-strategic-pressures/
  19. U.S. Geological Survey, "2025 Final List of Critical Minerals," 2025, https://www.usgs.gov/media/images/2025-list-critical-minerals
  20. U.S. Environmental Protection Agency, "Primary Copper Smelting: Final Rule," 2024, https://www.epa.gov/system/files/documents/2024-05/fr-notice-primary-copper-final.pdf
  21. The White House, "Proclamation on Temporary Exemptions for Primary Copper Smelters," 2025, https://public-inspection.federalregister.gov/2025-19775.pdf
  22. U.S. Environmental Protection Agency, "Nonferrous Metals Manufacturing Effluent Guidelines," 2026, https://www.epa.gov/eg/nonferrous-metals-manufacturing-effluent-guidelines
  23. U.S. Environmental Protection Agency, "Mineral Processing Waste," 2026, https://archive.epa.gov/epawaste/nonhaz/industrial/special/web/html/index-3.html
  24. Occupational Safety and Health Administration, "General Industry Standards: Lead, Arsenic and Beryllium," 2026, https://www.osha.gov/laws-regs/regulations/standardnumber/1910
  25. The White House, "Adjusting Imports of Copper into the United States," 2025, https://www.whitehouse.gov/presidential-actions/2025/07/adjusting-imports-of-copper-into-the-united-states/
  26. The White House, "Strengthening Actions Taken to Adjust Imports of Aluminum, Steel and Copper into the United States," 2026, https://www.whitehouse.gov/presidential-actions/2026/04/strengthening-actions-taken-to-adjust-imports-of-aluminum-steel-and-copper-into-the-united-states/
  27. Korea Zinc, "2026 Annual General Meeting Discussion Material," 2026, https://www.koreazinc.co.kr/en/wp-content/uploads/2026/03/Korea_Zinc_2026_AGM_Discussion_Material_English_1.0.pdf
  28. Grupo México, "Fourth Quarter Results 2025," 2026, https://docs.publicnow.com/viewDoc?filename=49740%5CEXT%5C2C6BCE08E50331093EA24FB7B75A4A930E95AFF8_CFB85922EAA092EAA1351518E827970145109DF3.PDF