Mining giant Rio Tinto announced that it has completed the transition to renewable diesel fuel from conventional diesel for all heavy mining equipment at its Kennecott copper mine in Utah, one of the world’s top producing copper mines.

Rio Tinto is one of the world’s biggest producers and processors of iron ore, copper, aluminum and a range of other minerals and materials. The company has committed to reduce its operational Scope 1 and 2 emissions by 50% by 2030, and to achieve net zero by 2050, with initiatives including switching to renewables at scale, electrification, developing new technologies and addressing emissions related to process heat at its refineries and processing operations.

According to Rio Tinto, the transition of the Kennecott mine’s fleet of 97 haul trucks and heavy machinery equipment to renewable diesel is expected to reduce the mine’s Scope 1 emissions by 450,000 tonnes, in addition to reducing PM2.5.(particulate matter less than 2.5 microns) emissions from the tailpipes of its haul truck fleet by 40%.

The renewable diesel being used is currently a combination of 90% soybean, in addition to animal fat and used cooking oil.

Clayton Walker, Rio Tinto’s copper chief operating officer, said:

“The transition to renewable diesel is a significant step toward our decarbonization goals at Kennecott where we have now reduced emissions by 80%, thanks to a range of initiatives in recent years. We remain committed to being responsible stewards of the environment and are always looking to find better ways to provide the materials the world needs for the energy transition.”

In 2023, Kennecott conducted an initial successful trial of renewable diesel, which compared two trucks using regular diesel against two using renewable diesel. Officials measured the trucks’ acceleration, cycle time, fuel usage, and engine inspection reports. This successful  renewable diesel trial follows similar positive test findings from the company’s boron mine in California, Rio Tinto said.  The transition to renewable diesel at Kennecott, combined with a full transition of heavy machinery from fossil diesel to renewable diesel at the boron mine in May 2023, has allowed Rio Tinto to successfully replace 11% of its global fossil diesel consumption with renewable diesel.

As an additional benefit, the move will make low-carbon fuel more accessible in the state of Utah, Rio Tinto said. In partnership with Kennecott, U.S. petroleum refiner HF Sinclair is dedicating two tanks to renewable diesel for the mine with each having a capacity of 18,000 barrels, or 756,000 gallons.

Steven Ledbetter, HF Sinclair executive vice president, commercial, said:

“We’re proud to support Rio Tinto’s sustainability journey with a low-carbon fuel produced at our facilities. We’re excited to see Kennecott move from trial to full implementation and what this could mean for other industries with evolving energy needs.”