The miner and the OEM are partnering to fast-track the development and implementation of zero-emission mine haulage solutions, including trucks.
Rio Tinto will conduct a pre-production trial of the equipment at one of its sites and has the option to buy some of the first trucks once they are commercially viable.
The miner has already been looking for zero-emissions haulage solutions, becoming a founding partner in the Austmine-created Charge On Innovation Challenge. Other founding partners are BHP and Vale.
That challenge centres on developing a battery electric solution for a 220t payload haul truck.
Rio Tinto chief commercial officer Alf Barrios said Rio Tinto and Komatsu had a shared partnership on innovation, pointing to their building the world's largest Komatsu autonomous haulage fleet in 2008.
"Our support of a trial, and the option to buy some of the first trucks from Komatsu, underscores our shared commitment to actively collaborate on product planning, development, testing and deployment of the next generation of zero-emission mining equipment and infrastructure as we look to decarbonise our business," he said.
Rio Tinto has also joined Komatsu's Greenhouse Gas Alliance, which has the initial target of advancing Komatsu's power agnostic truck concept for a hauler that can run on a variety of power sources including battery and hydrogen.
Besides Rio Tinto, founding members of that GHG Alliance are BHP, Chilean copper giant Codelco and Swedish mining and smelting group Boliden.
Komatsu mining business division president Max Moriyama said Rio Tinto and Komatsu both recognised the role zero-emissions haul trucks would play in meeting miners' GHG emission reduction goals.