Lithium miner Ioneer eyes bid for Rio’s US boron unit

Australian mining firm Ioneer Ltd. is interested in bidding on a bundle of Rio Tinto Group’s US assets that produce boron, a critical mineral used in fertilizer, according to its top executive.

Chief Executive Officer Bernard Rowe said he sees an opportunity to consolidate Ioneer’s boron-and-lithium project in Nevada with Rio’s boron operations in California that it’s seeking to sell. Bloomberg reported in late November on Rio’s plans to soon start a sales process to divest the assets.

“There are a lot of synergies between our two deposits,” Rowe said in a Friday interview. “We of course will be interested in looking.”

Boron, an element mineral with few producers, was added to the US list of critical minerals last month. It has a wide variety of industrial applications including in fertilizer, glass and ceramics manufacturing, fiberglass insulation and to strengthen metal alloys. It’s also used in rare-earth magnets found in motors and electronics.

Rio’s boron assets include a mine and processing operation in the Mojave Desert town of Boron, as well as a refinery and shipping facility in Los Angeles port and its Owens Lake mining operation near Sierra Nevada. Rio’s California operations meet about 30% of global demand for boron, according to the company’s website.

Ioneer owns Rhyolite Ridge in Nevada, one of two advanced lithium projects in the US that has financial backing from the government. Rhyolite Ridge faced a setback in February after South African firm Sibanye Stillwater Ltd. scrapped plans to take a major stake in the project.

Rowe said the company is now looking for new investors with the help of Goldman Sachs Group Inc. The company is in talks with a range of prospective partners, including private equity groups and chemical makers, and expects to secure new investment in the first half of 2026.

“We think we’ll be more successful with a consortium-style equity funding, rather than a single partner,” he said.

(By Jacob Lorinc)