Fortescue Sells First Arsenic-Cleaned Copper Concentrate Batch

Fortescue has sold its first batch of copper concentrate cleaned of arsenic using its own treatment process. The company says more than 40 tonnes changed hands and that the technology could make previously uneconomic copper deposits viable.

Arsenic is one of the most costly impurities in copper mining. Above certain levels it triggers smelter penalties, forces blending or leads to outright rejection. That leaves otherwise valuable copper in the ground.

A working, affordable removal route would matter to anyone tracking where future copper supply comes from.

Every performance figure in the announcement comes from Fortescue itself. This piece covers what the sale proves, what it leaves out, and the tests that will decide whether the process changes copper economics.

What did Fortescue actually sell, and what is still unproven?

What Fortescue has disclosed

The concentrate came from Fortescue’s Brisbane demonstration plant, which runs the Toowong Process. The process is a patented hydrometallurgical method, meaning it uses chemical solutions instead of high heat, and it operates at low temperature and low pressure. According to the company, and as reported by Australian Mining on 18 October 2026, the results were:

• Feedstock containing up to 7% arsenic
• Sold product containing under 0.25% arsenic
• Seven test campaigns covering more than 3,000 operating hours
• Arsenic cut below 0.3% across those campaigns, with more than 99.9% of the copper retained

Fortescue acquired the technology in 2022 and has spent roughly four years developing it. Engineering work continues, with a focus on lowering capital and operating costs. The company is also testing concentrate from its Cañariaco project in Peru, aiming to lift the share of saleable concentrate and potentially move more resource into mining inventory.

Cleaner copper production technology is gaining attention because traditional high-temperature processing faces mounting economic and environmental pressure, which is the context in which a low-temperature, low-pressure route becomes commercially interesting.

Fortescue’s claim The company says the process may make copper deposits viable that were previously not economically feasible to develop.

What remains undisclosed

The gaps are wide. Fortescue has not named the buyer, the destination or the sale date, and it has disclosed no commercial plant size, capital cost or start date. No independent analyst valuation of the sale was found.

This result should also be kept separate from Core Resources’ earlier pilot. That trial treated about 1.2-1.5 tonnes over 34 days, cutting arsenic from about 1.1% to 0.1%.

One accepted batch tells you the product met one buyer’s terms. It does not tell you a full-scale plant is bankable, so treat the sale as a credible proof point, not a commercial verdict.

How do arsenic penalties turn a copper deposit uneconomic?

How penalties and limits stack up

The problem starts in the rock. Arsenic-bearing minerals such as enargite and tennantite float alongside copper sulphides during processing, so the concentrate carries the arsenic with it. From there, the costs build:

1. Smelter limits: Smelters generally prefer concentrates below roughly 0.2-0.5% arsenic, and about 0.5% is commonly cited as a benchmark for Chinese imports.
2. Penalties: Illustrative deductions run at about US$2-3 per dry tonne for each 0.1% above the threshold, rising at higher levels.
3. Blending: Mines dilute dirty concentrate with scarce clean feed, which constrains mine sequencing.
4. Emissions burden: Arsenic turns to vapour during smelting, so dust and gas must be captured and stabilised.
5. Lost inventory: Ore that cannot clear these hurdles stays out of the mine plan.

These thresholds and penalties are indicative and not independently confirmed. There is no universal schedule; terms vary by smelter and contract.

Arsenic management strategies now shape project financing and permitting as much as plant design, which is why a low-cost removal route is judged against penalties, blending constraints and stranded resource rather than metallurgy alone.

How existing treatment routes compare

Roasting is the only route with established commercial operation for enargite concentrates, such as at Codelco’s Ministro Hales complex in Chile. A Codelco hydrometallurgy collaboration with Ecometales and Aurubis reportedly reached more than 98% arsenic leaching, fixing the arsenic as scorodite, a stable mineral. Both precedents are not independently confirmed.

For you as a reader, arsenic is a cost and permitting problem as much as a metallurgical one. Any technology only matters if it beats the combined cost of penalties, blending and stranded resource.

Could the technology change copper supply, or does the market not need it?

The upside is easy to sketch. A cheaper clean-up route could widen the usable resource base, give miners more blending freedom, narrow discounts on dirty concentrate and potentially convert Cañariaco resource into mining inventory.

What the supply forecasts say

How urgently the market needs that supply depends on whose forecast you trust. The figures below are not independently confirmed and differ in assumptions, dates, coverage and how each defines the market balance.

The International Copper Study Group (ICSG) sees surpluses; the banks see deficits. Either way, the technology’s value to you depends more on its cost and residue handling, neither of which has been disclosed.

The bank forecasts of a copper supply deficit rest on electrification demand colliding with constrained mining capacity, which is the scenario in which unlocking arsenic-bearing resource would matter most.

The tests still to pass

Removing arsenic does not destroy it. The residue still needs stable, permitted long-term storage, and rules differ across Australia, Peru and China. Cañariaco itself still needs approvals, infrastructure and financing. Core’s historical concept estimates of about US$37 million for a 40,000 tpa plant are not current Fortescue costs.

1. Continuous operation at full commercial scale
2. A stable, permitted arsenic residue
3. Acceptance by a wide range of buyers on normal terms
4. A cost below the value of penalties and lost inventory

These statements are speculative and subject to change based on market developments and company performance.

What the sale proves, and the disclosures that will show whether it matters

The sale is a real milestone, but it remains demonstration-scale. Whether it changes how miners treat arsenic copper concentrate depends on economics Fortescue has not yet published.

Watch for the buyer and terms, commercial plant size and capex, the residue management approach, and progress on Cañariaco studies. Until then, the performance claims remain Fortescue’s own.

This article is for informational purposes only and should not be considered financial advice. Investors should conduct their own research and consult with financial professionals before making investment decisions.