Rio Tinto: Biomass Replacing Coal in Steelmaking Process

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.

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, the company announced.

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. 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 – Rio Tinto Iron Ore Chief Executive Simon Trott said.

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.

Lignocellulosic biomass includes agriculture by-products (i.e. wheat straw, corn stover, barley straw, sugar cane bagasse) and purpose-grown crops, which would be sustainable sources for the process, the company says and add that, 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.

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.

Rio Sava Exploration d.o.o. Beograd

Rio Tinto

University of Nottingham

Pilbara

Simon Trott

steel

production

coal

biomass

lignocellulosic biomass

low carbon steel

coking coal

innovations

microwave technology

iron ore

CO2

emission

reduction