Services › Category 11 of 18

Ore, concentrate & mineral supply

Sellers of material, and buyers of it

This covers three different counterparties who all get called 'suppliers'. Producers sell physical material: run-of-mine or direct shipping ore, flotation concentrate (copper, lead, zinc, molybdenum), gravity and precious-metal concentrate, intermediates such as mattes, calcines, mixed hydroxide precipitate or crude oxide, and refined metal. Traders and offtakers sit between mine and smelter, buying at the mine gate or FOB port, blending parcels to a specification a given smelter will accept, and carrying the freight, financing, warehousing and price-risk functions a single mine cannot. Buyers are smelters, refiners, secondary processors and manufacturers looking for domestically sourced feed of known grade with impurity levels their plant and their permit can tolerate. The instrument that ties them together is a physical offtake or purchase contract, which is a far more detailed document than a metal price: it specifies weight and moisture determination, sampling and assaying protocol, which metals are payable and at what percentage, treatment and refining charges, penalty elements and thresholds, the quotational period used to fix the price, payment and provisional-payment terms, and the Incoterms rule.

2 firms working in this trade

Alphabetical. Nobody paid to be here

  • CoreTerTonopah, Nevada

    Silver producer shipping crushed ore under contract and milling ore into its own concentrates, from sites in Nevada and California

    coreter.com
  • Purebase CorporationSutter Creek, California

    Aggregates, markets and sells produced silver for US precious-metal producers, handling the sale from delivery through payment

    purebase.com

Listed because we found them, not because they asked or paid. Every entry was checked against the company’s own website; none of it is an endorsement, and we have no commercial relationship with anyone on this page. Work in Ore, concentrate and mineral supply and want to be added, corrected or removed? Tell us — it is free either way.

How it is actually bought

Contract shapes and what they price

A concentrate sale is not priced off the metal price; it is priced off the metal price minus a stack of deductions, and each deduction is negotiable. First, weight and moisture: the lot is weighed wet, moisture is determined by drying (ISO 10251 is the reference method for mass loss on drying of copper, lead, zinc and nickel concentrates), and payment is on dry metric tonnes, so a concentrate shipped at 9 percent moisture instead of 8 costs the seller a full percent of revenue. Second, assay and payable metal: independent sampling under ISO 12743 at load or discharge, then seller and buyer exchange assays, and if they differ by more than an agreed splitting limit an umpire laboratory named in the contract breaks the tie, usually with the loser paying the umpire's cost — so which laboratories are on the umpire list, and whether they are ISO/IEC 17025 accredited, is a real commercial term. Payable copper in a 2024 concentrate marketing study filed with the Impact Assessment Agency of Canada ran 96.5 to 96.6 percent with a minimum deduction of about 1.1 units, meaning the smelter pays for 96.5 percent of contained copper or grade minus 1.1 percentage points, whichever is less favourable to the seller; gold ran 97.5 to 98 percent payable with a 2 g/t minimum deduction and silver 90 to 97 percent with a 20 g/t minimum deduction. Third, treatment and refining charges: the TC is a per-dry-metric-tonne charge for smelting and the RC is a per-pound (copper) or per-ounce (gold, silver) charge for refining; the same study showed TCs quoted as benchmark plus or minus a percentage or as a flat figure in the US$63 to US$85/dmt range with copper RCs of 6.3 to 8.5 US cents/lb, gold RCs of US$4 to US$5/oz and silver RCs of US$0.40 to US$0.50/oz. The annual benchmark moves violently and must be dated whenever it is quoted: the 2025 copper benchmark was reported at $21.25 per tonne, Japanese term contracts settled in early February 2025 at $25 per tonne and 2.5 cents per pound, and by 21 November 2025 the spot treatment charge had gone to minus $42.32 per tonne against plus $10.64 a year earlier — a negative TC means the smelter is paying the miner to take the concentrate — with 2026 benchmark forecasts from fifteen industry sources clustered around zero. Fourth, penalties: deleterious elements are charged per increment above a threshold, with the same study showing arsenic at US$2 to US$3 per 0.1 percent up to 0.5 percent and US$8 to US$12 per 0.1 percent above 1 percent, antimony US$1 to US$2 per 0.01 percent, bismuth US$1.50 to US$3.00 per 0.01 percent, lead and zinc US$1 to US$5 per 1 percent, fluorine US$1 to US$2 per 100 ppm and mercury US$0.10 to US$5 per 1 ppm. Fifth, the quotational period: the price is not fixed on the bill of lading date but over an averaging window such as M+1 or two months after month of arrival ('2 MAMA'), sometimes with an option to price at any point before the QP begins, and that window is where a seller either hedges or gambles. Finally the Incoterms 2020 rule: the study used CIF for international smelter sales and DAP for domestic delivery, and because the rule fixes the delivery point, the risk transfer and who arranges and insures carriage, changing it changes the netback more than most TC negotiations do.

Who regulates it

And what each one requires of this trade

  • U.S. Securities and Exchange Commission (SEC) — Regulation S-K Subpart 1300 — Governs what a US-listed registrant with material mining operations may say about mineral resources and reserves. Resources must have reasonable prospects for economic extraction and are classified inferred, indicated or measured; reserves are the economically mineable part of a measured or indicated resource; disclosure must rest on a qualified person's work and a dated, signed technical report summary. If a counterparty's stated tonnes and grades are not S-K 1300 compliant, treat them as marketing.
  • U.S. Department of Commerce — Section 232 copper action — Section 232 national-security tariff authority now directly shapes the economics of domestic versus imported copper. A 50 percent tariff on semi-finished copper products and intensive copper derivative products took effect at 12:01 a.m. EDT on 1 August 2025, with a separate phased duty on refined copper (15 percent from 1 January 2027 and 30 percent from 1 January 2028) subject to a Secretary's update due by 30 June 2026, plus domestic sales requirements for copper input materials under Defense Production Act authority.
  • U.S. Customs and Border Protection (CBP) and the Harmonized Tariff Schedule — Classification, valuation, origin and duty on any imported ore, concentrate, intermediate or refined metal. The HTS is a 10-digit US import schedule administered by the USITC; Schedule B is the 10-digit US export schedule administered by the Census Bureau, and the first six digits of each are the WCO Harmonized System code. Rulings are searchable in CBP's CROSS database.
  • Mine Safety and Health Administration (MSHA) — Every domestic producer you might buy from is an MSHA-regulated mine or mill with an inspection and citation record. Where you are buying feed on a long-term contract, a supplier's MSHA compliance history is a genuine indicator of delivery reliability, not just a safety matter.

The standards that apply

Ask which of these a firm works to

  • Incoterms 2020 (International Chamber of Commerce) — The eleven ICC rules that set the delivery point, the moment risk passes, and who arranges and pays for carriage, insurance and export/import clearance. In a concentrate sale the choice between an FCA-type mine-gate term, CIF to a smelter port and DAP to a domestic plant moves the netback materially; the 2020 edition gathers all costs for each rule at articles A9/B9.
  • ISO 12743:2021 — Copper, lead, zinc and nickel concentrates: sampling procedures for determination of metal and moisture content — The reference sampling standard for concentrate trade, covering moving streams and stationary lots, treating stopped-belt sampling as the reference method against which mechanical and manual sampling are validated and moving-stream sampling as preferred. Slurries are out of scope. Write the standard into the contract, and name who supervises the sampling.
  • ISO 10251:2006 — Copper, lead, zinc and nickel concentrates: determination of mass loss of bulk material on drying — The reference method for determining moisture content of a concentrate lot as the percentage mass loss of the moisture test portion under specified drying conditions. Because payment is on dry metric tonnes, this standard is the difference between paying for metal and paying for water; it excludes drying of samples used for volatile elements such as mercury and sulphur.
  • ISO/IEC 17025:2017 — General requirements for the competence of testing and calibration laboratories — The accreditation standard that makes an assay defensible. Accreditation demonstrates a laboratory's competence to produce valid results and allows test reports and certificates to be accepted across borders without re-testing — which is precisely what an umpire assay clause depends on. Require it of the seller's laboratory, the buyer's laboratory and every laboratory on the umpire list.
  • Exchange-referenced pricing and the quotational period — A concentrate contract does not fix a price; it fixes a formula. Payable metal is multiplied by an exchange price series averaged over a defined quotational period — a month, a quarter, a window around shipment or arrival — so the same tonne is worth different money depending on which window the contract names. Exchange contracts settle only against approved brands into approved warehouses, which is why refined metal and concentrate price very differently.

What to demand from a firm

Credentials worth checking before you sign

  • Qualified Person under SEC Regulation S-K Subpart 1300 — A mining professional with at least five years of relevant experience in the specific mineralisation and deposit type, in good standing with a recognised professional organisation, who signs and dates the technical report summary. For reserves the report must be a pre-feasibility or final feasibility study with discounted cash flow; for resources, an initial assessment with economic analysis. Ask which QP signed, when, and against which category.
  • ISO/IEC 17025 accreditation for the assay and umpire laboratories — Accreditation to ISO/IEC 17025 is the evidence that a laboratory is technically competent and that its certificates will be accepted by the other side and, if needed, in arbitration. Demand the accreditation certificate and the scope annexe covering the specific analytes and matrices in your concentrate, not just a general claim of accreditation.
  • An independent sampling and inspection appointment under ISO 12743 — Sampling should be done by a party independent of both seller and buyer, to a written protocol referencing ISO 12743, with sealed and retained samples for seller, buyer and umpire. If the seller samples its own lot and the buyer re-samples on discharge, every assay dispute becomes an argument about whose sample was representative rather than about the metal.
  • Licensed customs broker with a permit for the port of entry (for imported or exported material) — Only a CBP-licensed broker holding a permit for the district, or a national permit, may transact customs business as your agent. The importer of record — not the broker — remains liable for duty, classification and penalties, which after the 2025 Section 232 copper action is a materially larger exposure than it used to be.

Where to find firms yourself

Public registers and member directories

  • USGS Mineral Commodity Summaries (National Minerals Information Center) — The earliest government publication of nonfuel mineral industry estimates, covering more than 90 minerals and materials with domestic industry structure, government programmes, tariffs and five-year salient statistics per commodity. This is how you establish, before you talk to anyone, how many US mines produce your commodity, in which states, and how import-dependent the country is.
  • MSHA Mine Data Retrieval System — Current and historical MSHA data mine by mine for every coal and metal/nonmetal mine and contractor in the country, searchable by operator and location. It is the most complete public register of who is actually operating a mine or mill in the United States, and it doubles as a due diligence check on a prospective supplier's compliance record.
  • SEC EDGAR full-text search — Full text of electronic SEC filings since 2001, searchable by phrase, company, form type and date. Searching offtake, treatment charge or concentrate sales terms in 10-K, 20-F, 8-K and technical report summary exhibits is the single best public source for what real contracts in your commodity actually say, because material contracts get filed.
  • CBP Permitted Customs Brokers Listing — CBP's published, downloadable list of permitted customs brokers by port and district. Relevant on the supply side whenever material crosses a border in either direction, and the place to verify that a broker proposed by a trading counterparty holds a current permit.

Numbers worth knowing

Each one carries its source

2025 copper concentrate benchmark TC reported at $21.25 per tonne; spot treatment charges were minus $42.32 per tonne on 21 November 2025 against plus $10.64 a year earlier; 2026 benchmark forecasts from 15 industry sources ranged from minus $30 to plus $10 per tonne, clustered around zero

Annual copper concentrate treatment and refining charge benchmarks, with the spot market for comparison. Note the direction of travel and the fact that spot went deeply negative, meaning smelters paying miners to take concentrate. Treatment and refining charges move constantly — any TC/RC figure is a dated benchmark, not a rate card, and must be re-checked against the current market before it goes into a model.

source
Payable copper 96.5-96.6% with a minimum deduction of about 1.1 units; gold 97.5-98% payable with 2 g/t minimum deduction; silver 90-97% payable with 20 g/t minimum deduction; gold RC US$4-5/oz, silver RC US$0.40-0.50/oz; indicative TCs US$63-85/dmt with copper RCs of 6.3-8.5 US cents/lb

Indicative commercial terms from a 2024 concentrate marketing study filed with the Impact Assessment Agency of Canada, comparing several smelter and trader term sheets for a copper-gold concentrate. Useful as a structural template for what a term sheet contains; the levels are dated and the benchmark component has since moved to zero. These figures come from a single concentrate marketing study filed for one Canadian project in June 2024, not from a published market norm — the shape of the terms is the lesson, not the rates.

source
Indicative penalties: arsenic US$2-3 per 0.1% up to 0.5% and US$8-12 per 0.1% above 1%; antimony US$1-2 per 0.01%; bismuth US$1.50-3.00 per 0.01%; lead and zinc US$1-5 per 1%; fluorine US$1-2 per 100 ppm; mercury US$0.10-5 per 1 ppm

Deleterious-element penalty structures from the same 2024 filed marketing study. The point is not the exact rate but the shape: penalties are stepped, they escalate sharply above a second threshold, and a concentrate that is clean on metal but dirty on arsenic or fluorine can be effectively unsellable to some smelters at any price.

source
US mine production of recoverable copper was an estimated 1.0 million tons in 2025, from 26 mines in 8 states; Arizona was about 70% of output; refinery production 850,000 tons (790,000 primary, 60,000 secondary); net import reliance 57% of apparent consumption

USGS Mineral Commodity Summaries 2026 figures for copper. Refined copper was 88 percent of unmanufactured copper imports, with Chile 68 percent, Canada 16 percent, Peru 7 percent and Mexico 6 percent — which is the context for any claim about domestically sourced feed.

source
50 percent Section 232 tariff on semi-finished copper products and intensive copper derivative products from 12:01 a.m. EDT on 1 August 2025; phased refined copper duties of 15 percent from 1 January 2027 and 30 percent from 1 January 2028 subject to a report due 30 June 2026

The 2025 copper proclamation. Refined copper was not tariffed at the outset but is on a phased schedule under review, and separate domestic sales requirements for copper input materials were directed under Defense Production Act authority. Any US concentrate or refined-metal netback calculation now has to state which tariff regime it assumes and on what date.

source

How this goes wrong

The specific traps, not general advice

  • Negotiating hard on the treatment charge and ignoring the payable percentage, the minimum deduction and the penalties. A one-unit change in payable copper or an arsenic threshold set a tenth of a percent too low can outweigh every dollar won on the TC, and the benchmark TC itself collapsed from $21.25 per tonne in 2025 toward zero for 2026 while payables and penalties barely moved.
  • Leaving the quotational period and the hedging responsibility unstated. If the price is averaged over two months after month of arrival and nobody hedged, the seller has written an unfunded option on the metal price between shipment and pricing, which on a large parcel can exceed the entire margin on the sale.
  • Accepting the buyer's assay with no assay exchange, no agreed splitting limit and no named umpire laboratory. Without a contractual tie-break mechanism and ISO/IEC 17025-accredited laboratories on both sides, an assay dispute on a single cargo becomes an arbitration with no technical basis for resolving it.
  • Paying on wet tonnes, or letting the counterparty determine moisture on its own sample. Payment is on dry metric tonnes; ISO 10251 exists precisely because a percentage point of moisture is a percentage point of revenue, and moisture also drives transportable moisture limit and cargo liquefaction risk on the marine leg.
  • Believing tonnage and grade numbers that are not from a qualified person's signed technical report summary. Under SEC Subpart 1300 a resource is only a concentration with reasonable prospects for economic extraction, while a reserve requires a pre-feasibility or feasibility study with discounted cash flow — a supplier quoting 'resources' as if they were deliverable feed is quoting something that may never be mined.

Questions to ask before you sign

  • Where did this material actually come out of the ground?
  • What are the penalty elements, and who assays on dispute?
  • Can you supply consistently, or is this a single parcel?

Where to next

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Builders and contractors that put the plant up

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Moving ore, concentrate and equipment

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