Rio Tinto's California Boron Assets Attract Over a Dozen Bidders, Valued at Up to $2 Billion

Rio Tinto's U.S. boron operations in California have caught the attention of more than a dozen potential buyers, with the assets estimated to be worth as much as $2 billion, according to a Bloomberg News report. Companies including WE Soda, Magris Resources, and U.S. Silica Holdings are among the interested parties, with binding offers expected to be submitted by June.

Boron has become one of the most strategically important minerals in today's energy and industrial landscape. The versatile mineral plays a critical role in nuclear energy production, wind turbine manufacturing, specialty glass, advanced ceramics, high-performance insulation, agricultural fertilizers, cleaning products, and oil and gas drilling operations. Its wide range of applications across both traditional and clean energy industries has made it a highly sought-after resource.

The heightened interest follows the U.S. Geological Survey and the Interior Department officially adding boron to the national critical minerals list in 2024. This designation reflects growing concerns around global supply concentration, limited substitution options, and potential vulnerabilities in domestic supply chains — all factors that have pushed boron further into the spotlight for investors and industrial buyers alike.

For Rio Tinto, the potential sale aligns with a broader corporate strategy unveiled by CEO Simon Trott in 2025. The Anglo-Australian mining giant — widely recognized as the world's largest iron ore producer — outlined an ambitious plan to raise between $5 billion and $10 billion through strategic divestments and improved operational productivity. Offloading the boron assets would mark a meaningful step toward streamlining the company's portfolio and sharpening its focus on core mining operations.

With the deadline for binding offers approaching, competition for these California assets is expected to intensify, reflecting strong investor appetite for domestically sourced critical minerals amid ongoing global supply chain concerns.