Boron from the air

California operations









2023 figures

Boron, California

We mine borates, a naturally occurring mineral, from our mine in Boron, California, which we then refine and transform into products essential to modern living. Boron is vital to plant growth, so it is used in fertilisers, but it is also used in other industries such as glass manufacturing, wood protection and insulation fibreglass – to name just a few.

Mining at Boron began in 1927 and today, the mine – home to one of the richest deposits of borates in the world – produces one million tonnes of refined borates every year, or approximately 30% of global demand. We mine trona to process borates at our Owens Lake operation and refine and ship borates from our Wilmington port facility.

Decarbonising our operations

At Boron, we continually aim to improve our productivity, the safety of our team and to minimise our environmental impact.

We have lowered our water use by millions of gallons through recycling – a critical goal given our location in Southern California.

We have fully transitioned our heavy machinery to renewable diesel – the first open pit mine in the world to achieve this milestone. This brings an anticipated CO2 equivalent reduction of up to 45,000 tonnes per year, comparable to eliminating the annual emissions of approximately 9,600 cars

And we’ve partnered with CR Minerals to recycle waste materials from our Boron operations into pozzolans, a replacement for cement in concrete.

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U.S. Borax

U.S. Borax, part of Rio Tinto, is a global leader in the supply and science of borates - naturally-occurring minerals containing boron and other elements. From the very beginning, we have been on the forefront of borate technology, research, and development.

We're finding better ways to provide the materials the world needs. From our California operations, U.S. Borax supplies around 30% of the world’s need for refined borates. Our customers rely on boron and borates to create an extraordinarily diverse range of products essential to life and to modern living.
Wilmington at night, Boron
Supply-Chain Reliability: Our Wilmington facility at the Port of Los Angeles has been in continuous operation since 1924. The refinery and shipping operation produces and ships more than 36,000 tons of packaged goods and more than 300,000 tons of bulk material to customers in Europe, Malaysia, and China.

California operations communities

Cultural heritage

Our mine is operated by our borates business, U.S. Borax, which is one of America’s oldest and most iconic businesses. Originally established in Death Valley, the mine’s “Twenty Mule Team” would transport the borates through the harsh desert environment, ready for distribution to customers.

To this day, U.S. Borax celebrates its unique history by bringing the mule team back to life for special events and celebrations, both in Nevada and California.

In the early 20th century, the small town of Ryan was established to accommodate the hundreds of miners employed at the Death Valley site. From 1914–27, it was also the centre of borates mining, complete with a hospital, post office, school and a building that served as a church, movie theatre and recreation hall.

In 2013, Rio Tinto turned over the now-ghost town of Ryan to the Death Valley Conservancy (DVC), protecting its valuable cultural heritage for future generations. The DVC is meticulously working to restore the site.

The Twenty Mule Team in action
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Discover more about life at Rio Tinto.

Contact California Operations

U.S. Borax
14486 Borax Road
Boron, CA 93516 USA