Rio Tinto said to draw interest for critical mineral assets in California

Rio Tinto Group has drawn interest from more than a dozen potential bidders for its US assets that produce the critical mineral boron, according to people familiar with the matter.

The Anglo-Australian company could fetch around $2 billion for the assets, according to the people, who asked not to be named discussing private information. WE Soda, Magris Resources Inc., and US Silica Holdings Inc. are among the firms interested in buying Rio’s boron assets in California, they said. Boron is used in fertilizers as well as in high-tech applications such as heat-resistant glass and materials for renewable energy.

The companies are expected to extend binding offers to Rio Tinto by June, one of the people said. WE Soda is the world’s largest producer of soda ash, used in glass manufacturing and chemical processing. Magris is a Toronto-based mining investment firm. US Silica is one of the world’s top producers of silica sand, a raw material for glassmaking and construction, and is a portfolio company of Apollo Global Management Inc.

Rio Tinto declined to comment. Spokespeople for WE Soda, Magris Resources, US Silica Holdings and Apollo Global Management didn’t immediately respond to requests for comment.

The sale process comes as the Trump administration aims to boost domestic production of minerals it deems crucial to the US economy and national security. Critical minerals have become a potent lever in the US-China trade standoff, with Beijing controlling much of the global supply chain.

Rio decided last year to divest the US boron assets late last year as it looked to streamline its extensive operations under new chief executive officer Simon Trott, Bloomberg News reported in November.

Rio’s boron business includes a mine and processing operations in the Mojave Desert town of Boron, as well as a refinery and shipping facility at the Port of Los Angeles and its Owens Lake mining operation near the Sierra Nevada mountains. Rio’s California operations meet about a third of global demand for refined boron, according to the company’s website.

Aside from its wide variety of industrial applications, boron is key to stabilizing permanent rare-earth magnets, used in motors, generators and electronics. The US and Turkey are the world’s largest producers of the mineral, according to the US Geological Survey, with American production solely in California. The USGS added boron to its latest list of critical minerals in November.

(By Yvonne Yue Li, Jacob Lorinc and Thomas Biesheuvel)