Ioneer Signs Non-Binding LOIs with KIND and Hyundai to Advance Rhyolite Ridge toward 2H26 FID

Ioneer (ASX: INR) has signed non-binding strategic letters of intent (LOI) with Korea Overseas Infrastructure & Urban Development Corporation (KIND) and Hyundai Engineering to help advance its Rhyolite Ridge project in toward a final investment decision (FID) targeted for the second half of 2026.

Rhyolite Ridge is Ioneer’s 100%-owned lithium-boron project in Nevada, USA.

The company describes it as the only known lithium-boron reserve in North America and the only project of its kind in active development.

The project has been Ioneer’s central development focus for years, with work spanning environmental approvals, technical studies, engineering, and partner discussions.

In prior March quarter filings, the company said the project’s federal permit was upheld by the US District Court for Nevada on 31 March 2026 after a challenge to the Bureau of Land Management Record of Decision.

However, plaintiffs later appealed to the Ninth Circuit on 9 April 2026, leaving an active legal overhang even as Ioneer said it did not expect the appeal to delay construction.

US Critical Minerals Supply

Rhyolite Ridge also sits within broader US critical minerals policy settings.

Ioneer previously disclosed a US$996 million project loan that closed in January 2025 through the US Department of Energy’s Office of Energy Dominance Financing.

That funding context is important because the project remains pre-FID and still needs execution, timing and capital pieces to come together.

The company has also outlined product expansion studies around the core project.

In earlier quarterlies, Ioneer said it was preparing a pre-feasibility study for a battery-grade lithium carbonate circuit and had engaged Fluor to prepare a pre-feasibility study for defence-grade boron carbide.

Numbers and Timelines

Ioneer said it has invested more than US$220 million in Rhyolite Ridge since 2016 and completed more than 70% of advanced engineering work.

The company continues to target FID in the second half of 2026, with first commercial production expected in 2029.

Earlier context filings said construction is expected to take about 36 months, subject to lead times and when orders are placed.

The latest filing also reiterated project economics released in October 2025 outlining planned annual output of 27,800 tonnes per annum of lithium hydroxide and 135,500tpa of boric acid.

Ioneer also said the operation is expected to support around 275 to 300 permanent on-site roles.

What to Watch Next

The first milestone is whether these LOIs progress into the memorandums of understanding that Ioneer said are expected in July 2026.

More important than the labels, however, will be whether any future agreements contain binding commitments around equity, structured financing, engineering services or project delivery.

There is also a broader strategic process running alongside this announcement.

In March quarter disclosures, Ioneer said its strategic partnering process had been launched in June 2025, was expected to conclude by the end of the June quarter, and was more likely to result in a consortium than a single partner.

Today’s LOIs with KIND and Hyundai Engineering appear to sit within that wider partnering effort.

Regulatory timing remains another live issue. While the district court upheld the federal permit, the Ninth Circuit appeal is still active, with an anticipated decision in mid-2027 according to prior filings.

Ioneer has said the appeal is not expected to delay construction, but the legal process remains part of the risk profile.

Partnering Progress, Not Certainty

Ioneer’s latest filing adds a potentially useful strategic layer to the Rhyolite Ridge development story by bringing KIND and Hyundai Engineering into the frame ahead of a targeted second-half 2026 FID.

But the market still needs evidence that these non-binding LOIs turn into binding funding, engineering or delivery commitments, while permitting appeals, execution timing and future capital needs remain central to the project’s risk profile.

Cash runway and spending discipline also warrant attention as the project shifts from studies and permitting toward potential development activity.

The March quarter included no production or development activities, and the company’s filings continue to point to execution timing, future capital needs and possible dilution as relevant factors if additional funding is required later in the build-out.