Resource upgrades dominated the mining news agenda, with four companies across the cap spectrum reporting improved underlying asset quality even as share prices reacted unevenly. Phoenix Copper's enlarged Empire reserve headlined the day, while Aterian's Rwandan trading unit, Amaroq's Greenland exploration programme and Goldplat's South African tailings resource all pointed to incremental but tangible gains in project economics.
Phoenix Copper lifts Empire reserve 31% ahead of revised study
Phoenix Copper (AIM:PXC) has increased the proven and probable mineral reserves at its Empire open-pit mine in Idaho to 13.27 million tonnes, a 31.49% rise in ore tonnes against the May 2024 inaugural estimate, even as the shares slipped 8.3% to 0.55p. Empire sits in the Alder Creek mining district near Mackay, Idaho, where Phoenix holds an 80% stake in a historic underground mine that once produced copper, gold, silver, zinc and tungsten, and which the company is now advancing toward an open-pit operation.
The updated reserve contains 118.78 million lbs of copper, 134,600 ounces of gold and 5.41 million ounces of silver, equivalent to 83,959 tonnes of copper equivalent metal, a 26.31% increase on the prior estimate. The figures, prepared by Hardrock Consulting under NI 43-101 standards, follow Phoenix's August appointment of Hardrock alongside metallurgist Deepak Molhatra and Valley Science and Engineering to update the 2024 Empire pre-feasibility study. That September 2024 study had put Empire's pre-tax net present value at US$87.86 million with a 46.4% internal rate of return, based on reserves of 10.1 million tonnes and trailing prices of $4.45 per pound of copper, $2,325 per ounce of gold and $27.25 per ounce of silver.
"I am very pleased to report the 2026 Empire open-pit mineral reserve update," said Ryan McDermott, Chief Executive.
The timing matters because copper, gold and silver have all traded well above the price assumptions underpinning the 2024 study, a gap management flagged at September's half-year results as a tailwind for project economics once captured in the revised feasibility work. A larger reserve base combined with materially higher commodity prices sets up the prospect of a substantially improved net present value when the updated pre-feasibility study lands, though the market's muted reaction suggests investors are waiting for that study, rather than the reserve update alone, before re-rating the stock.
Eastinco's October exports climb as Kigali facility opens
Aterian (LSE:ATN) said export volumes at its Rwanda-based trading subsidiary Eastinco reached 20 metric tonnes in October, with the shares easing 2.1% to 23.5p despite the improving momentum at the unit. Eastinco has agreed to sell 10 metric tonnes of tantalum-bearing concentrate to a G7-based investor in a deal worth approximately $1.8 million, a transaction Aterian said broadens the subsidiary's customer base and demonstrates investor appetite for responsibly sourced physical tantalum.
The company's new Kigali facility is now operational, giving Eastinco a base for mineral handling and processing as it expands its supply network and international customer relationships. Aterian is also building relationships with additional mines in Rwanda to support future deliveries of tantalum- and tungsten-bearing material, though converting these into regular supply will depend on due diligence, traceability and material quality checks. "Eastinco is beginning to deliver the performance we have been working towards," said Charles Bray, Executive Chairman, adding that "export volumes reached 20 tonnes in October, our new Kigali facility is operational, and we are building relationships with additional Rwandan mines to support new supply."
The progress signals Eastinco is transitioning from a development-stage trading operation into one with repeatable export volumes and a widening customer base, a shift that matters for Aterian's broader strategy of building a diversified critical minerals trading and exploration business across Africa.
Amaroq charts multi-deposit strategy with high-grade zinc hits
Amaroq (LSE:AMRQ) unveiled a "String of Pearls" development strategy for its Maarmorilik project in West Greenland, pairing the plan with new high-grade exploration results from surrounding zinc-lead-silver and critical metal deposits, as shares ticked up 0.4% to 97.6p. The London and Nasdaq Iceland-listed company, which is building a multi-asset mining business in Greenland around its producing Nalunaq gold mine, reported channel and rock chip sampling at targets named Garde, Wedge, Glacier and Myers returning zinc grades as high as 62.2%, alongside lead, silver and the critical metals germanium and gallium.
Garde delivered a channel sample of 3.1 metres at 17.49% zinc, 8.08% lead and 36 grammes per tonne silver, with 159.2 parts per million gallium and 107.5 parts per million germanium, while rock chip results there reached 62.2% zinc. Wedge returned 4.1 metres at 10.05% zinc, 0.5% lead and 5 g/t silver with 181.5 ppm gallium, and rock chips there reached up to 26.8% zinc with 517 ppm gallium, while Glacier and Myers also produced rock chip results supporting the broader mineralised footprint around Maarmorilik.
The "String of Pearls" framing signals Amaroq intends to develop Maarmorilik not as a single orebody but as a cluster of satellite deposits feeding shared infrastructure, a model that could extend mine life and spread capital costs across multiple high-grade zinc targets, an approach that, if it holds up through further drilling, strengthens the case for Maarmorilik as a second production pillar alongside Nalunaq.
Goldplat nearly doubles tailings gold resource in South Africa
Goldplat (AIM:GDP) has upgraded the JORC-compliant mineral resource estimate for the tailings storage facility at its 90.63%-owned South African subsidiary Goldplat Recovery, lifting the gross contained gold estimate to 130,560 ounces from 81,959 ounces previously, with shares rising 5.7% to 23.25p. The new estimate, effective 31 August and prepared by Sound Mining International, puts the resource at 2.34 million tonnes grading 1.74 g/t gold, all classified as Measured, of which 118,330 ounces are attributable to Goldplat.
The figure compares with 81,959 ounces of gold in 1.43 million tonnes announced in January 2016, which the new estimate supersedes; that earlier figure included material in footwall soils beneath the facility that has not been carried into the 2026 estimate. "The upgraded JORC Resource is an important step in unlocking the value of the TSF, although it will take time to ensure operational readiness," said Werner Klingenberg, Chief Executive.
The nearly 60% uplift in contained ounces gives Goldplat a materially larger processing target at its South African recovery operation, though management's own caution on operational readiness signals the resource upgrade is a valuation milestone rather than an immediate production trigger.