This amounts to an increase of 186.6Mt, with 48% of the mineral resource now converted into a reserve which is estimated to comprise 1,464 ppm (parts per million) lithium and 5,444 ppm boron – or 1.92 Mt of lithium carbonate equivalent (LCE) and 7.68 Mt of boric acid equivalent (BAE).

These parameters support Ioneer’s plans to build a large, long-life, low-cost expandable operation, focused on the production of lithium carbonate, boric acid and then battery-grade lithium hydroxide.

The co-product of boric acid is expected to make up 25% of annual revenue from the project in its first 25 years; this is set to keep EBITDA (earnings before interest, taxes, depreciation and amortization) in the green at low lithium prices and EBITDA margin of65.7% based on average production over first 25 years.

Costs for the Rhyolite Ridge are some of the lowest among global lithium projects, with an all-in sustaining cash cost of US$5,745 per metric tonne lithium carbonate equivalent. Meanwhile, its after-tax NPV is placed at US$1.367 billion, with an unlevered, after-tax internal rate of return (IRR) of 14.5% – making for a suite of robust economics.

Managing director Bernard Rowe said the reserve update was testament to the value of the mineralisation there.

“Today’s updated Reserve and Mine Plan reinforces the importance of Rhyolite Ridge’s remarkable mineralogy,” he said.

“Our Ore Reserve estimate of 247 Mt containing a total of 1.92 Mt LCE and 7.68 Mt BAE make it the largest lithium-boron Reserve in the world.”

Ioneer shares have moved higher since the news, and at 13:17 AEST, they were trading at 13 cents – a rise of 8.33% since the market opened.

Join the discussion: See what HotCopper users are saying about Ioneer and be part of the conversations that move the markets.

Listen to the HotCopper podcast for in-depth discussions and insights on all the biggest headlines from throughout the week. On Spotify, Apple, and more.

The DFS was built around production of 1.4 million tonnes per annum through open-cut mining, for a yield of 3,405 tonnes of contained tin per year, in the form of tin ingot.

This is expected to run for a mine life of 12 years, with a life of mine (LOM) all-in-sustaining-cost (AISC) of US$15,000 per tonne of tin metal.

The capital costs are now estimated at €149 million (A$260M), including a 10.4% contingency. With the study assuming a LOM tin price of US$30,000/t, it has confirmed a pre-tax ungeared net present value of A$270M, a pre-tax internal rate of return (IRR) of 26%, and a payback period of 2.7 years.

Alongside this, Elementos told investors the maiden ore reserve for Oropesa was estimated at 15.9Mt at 0.36% tin, with this being based on a previously published mineral resource estimate of 19.6Mt at 0.39% Sn.

Development activity for the project – which is built around a vertically integrated mine-to-metal smelting operation – continues to progress, with Environmental and Mining Licence permit applications recently lodged.

“I would like to congratulate the Elementos/Wave International team, the specialist consultants and the Spanish contractor community on the production of this top-class definitive feasibility study,” chairman Andy Greig said.

More market news

Levy beef: Trump whacks Oz with 10% tariffs on “Liberation Day”

Meet GeoGeorge: The HotCopper poster so accurate he got hired as an analyst

“My fellow directors and I have undertaken a deep-dive review of this work product, and I am pleased to report we’ve found the DFS to be of great substance; prudently conservative; comprehensive and robust.”

Elementos shares moved up today for a 3.4% gain in value.

Join the discussion: See what HotCopper users are saying about Elementos Ltd and be part of the conversations that move the markets.

The material provided in this article is for information only and should not be treated as investment advice. Viewers are encouraged to conduct their own research and consult with a certified financial advisor before making any investment decisions. For full disclaimer information, please click here.