Rio Tinto targets low-carbon steel production with new tech

Mining company, Rio Tinto, is progressing an innovative new technology to deliver low-carbon steel, using sustainable biomass in place of coking coal in the steelmaking process.

This has potential to cut industry carbon emissions and serve as a cost-effective option.

Over the past decade, Rio Tinto has developed a laboratory-proven process that combines the use of raw, sustainable biomass with microwave technology to convert iron ore to metallic iron during the steelmaking process. The patent-pending process, one of a number of avenues the company is pursuing to try to lower emissions in the steel value chain, is now being further tested in a small-scale pilot plant.

If this and larger-scale tests are successful, there is the potential over time for this technology to be scaled commercially to process Rio Tinto’s iron ore fines.

“We are encouraged by early testing results of this new process, which could provide a cost-efficient way to produce low-carbon steel from our Pilbara iron ore,” said Rio Tinto Iron Ore Chief Executive, Simon Trott.

“More than 70 per cent of Rio Tinto’s Scope 3 emissions are generated as customers process our iron ore into steel, which is critical for urbanisation and infrastructure development as the world’s economies decarbonise.

“So, while it’s still early days and there is a lot more research and other work to do, we are keen to explore further development of this technology.”

Rio Tinto Iron Ore Chief Executive, Simon Trott.

Rio Tinto’s process uses plant matter known as lignocellulosic biomass, instead of coal, primarily as a chemical reductant. The biomass is blended with iron ore and heated by a combination of gas released by the biomass and high efficiency microwaves that can be powered by renewable energy.

Rio Tinto researchers are working with the multi-disciplinary team in the University of Nottingham’s Microwave Process Engineering Group to further develop the process.

“It is really exciting to have the opportunity to be part of a great team working on a technology that, if developed to commercial scale, has the potential to have a global impact through decarbonising key parts of the steel production process,” said Professor Chris Dodds, Head of Department, Chemical and Environmental Engineering at the University of Nottingham.

The use of raw biomass in Rio Tinto’s process could also avoid the inefficiencies and associated costs of other biomass-based technologies that first convert the biomass into charcoal or biogas.

Lignocellulosic biomass includes agriculture by-products (such as wheat straw, corn stover, barley straw, sugar cane bagasse) and purpose-grown crops, which would be sustainable sources for the process.

Importantly, the process cannot use foods such as sugar or corn, and Rio Tinto would not use biomass sources that support logging of old-growth forests.

“We know there are complex issues related to biomass sourcing and use and there is a lot more work to do for this to be a genuinely sustainable solution for steelmaking,” said Trott. “We will continue working with others to understand more about these concerns and the availability of sustainable biomass.”

If developed further, the technology would be accompanied by a robust and independently accredited certification process for sustainable sources of biomass.

In line with this initiative, Rio Tinto is looking to further decarbonise its operations and grow.

Decarbonisation of the Pilbara will reportedly be accelerated by targeting the rapid deployment of 1GW wind and solar power which would abate around one million tonnes of carbon dioxide, replacing natural gas power for plant and infrastructure as well as support the early electrification of mining equipment.

Taking electrification further, the Pilbara system, including all trucks, mobile equipment and rail operations, would require further gigawatt-scale renewable deployment and advances in fleet tech.

Rio Tinto Aluminium is touted to be the most profitable integrated aluminium business with an advantaged position in renewable energy.

Options are reported to be progressing to switch Boyne Island and Tomago smelters in Australia to renewable energy which will require an estimated 5GW of solar and wind power along with a robust firming solution.

Demand growth and supply-side constraints including ongoing pressures on fossil-fuel sourced energy, according to Rio Tinto, makes this an attractive structural change.

In other news, Rio Tinto welcomes the final report of the Joint Standing Committee on Northern Australia following its inquiry into the destruction of rock shelters at Juukan Gorge on the land of the Puutu Kunti Kurrama and Pinikura people (PKKP) in the Pilbara region of Western Australia.

The mining company, in August 2020, published a review of its failure at Juukan Gorge to prevent similar incident occurring in the future.

Rio Tinto has followed through on its commitment to improving, strengthening and amending practices, work culture and governance.

The work being undertaken includes a review of more than 2,205 heritage sites, commencing agreement modernisation discussions with 10 Pilbara Traditional Owner groups and their representatives, collaborating on cultural heritage management and establishing an advisory group to inform policies and positions important to Indigenous Australians and business.

The company has invested $50 million in retaining, attracting and growing Indigenous professional and leaders in Rio Tinto’s Australian operations. All staff in Australia also undertake cultural awareness training with face-to-face training or e-learning with Indigenous Australians.

“Our determination not to repeat the events leading up to the destruction of the Juukan Gorge rock shelters is ingrained in everything we do,” said Rio Tinto Chief Executive – Australia, Kellie Parker.

“Significant changes have been made at all levels of our business and this is continuing. While we are confident we have put in place the right foundations for a better future, we know we will be judged by our actions and we are determined to get it right. The important work of the committee has helped reinforce our priorities as we work to rebuild trust.

Rio Tinto Chief Executive – Australia, Kellie Parker.

“We will continue to work in close consultation with Traditional Owners to better understand and protect their cultural heritage and ensure future mining activity is done in the right way, to create meaningful social and economic benefits.

“We thank the PKKP people and Traditional Owners everywhere for their engagement as we continue this vital work.”

It’s no secret that the ongoing Covid-19 pandemic has been causing global shipping delays affecting Australian businesses in more ways than thought possible. At a time like this the importance of an Australian supply chain really comes to the surface. Australia’s leading manufacturer and distributor of aluminium products, Capral, understands what it means for local manufacturing and the businesses that depend on it.