Rio eyes biomass for steel, unlike Australian rivals

UK-Australian iron ore producer Rio Tinto pushes biomass in making green steel, as Australia's three biggest iron ore exporters explore three different methods of reducing emissions in steelmaking.

Rio Tinto has developed the BioIron process in Germany and will build a 1 t/hour pilot plant to test its capacity to economically produce metallic iron from the firm's Pilbara iron ore. The process mixes biomass with Pilbara iron ore to act as a reductant and harnesses microwave energy — potentially from renewable sources — to power the conversion to metallic iron.

"BioIron is just one of the pathways we are developing in our decarbonisation work with our customers, universities and industry to reduce carbon emissions right across the steel value chain," Rio Tinto chief commercial officer Alf Barrios said.

Rio Tinto's two biggest Pilbara iron ore rivals each have their own preferences of cutting emissions in steelmaking. Australian firm BHP — the only one of these three to own large-scale coking coal production assets — is focused on cutting emissions from traditional blast furnace steel production. Fortescue Metals plans to use new technology to produce steel using iron ore and green hydrogen.

Fortescue Future Industries (FFI), which is the decarbonisation arm of Fortescue, announced last week that it had agreed to work with Indonesian steelmaker PT Gunung Raja Paksi to investigate how FFI's green hydrogen and green ammonia could be used to decarbonise the production of direct reduced iron and hot briquetted iron. Fortescue has previously pushed its building capacity to produce metallic iron in the Pilbara region by using new technology and green hydrogen to convert either magnetite concentrate from its Iron Bridge project or lowergrade direct shipping ore.

BHP is investing in its Queensland coal assets because it expects that the biomass and hydrogen-based green coal solutions envisaged by Rio Tinto and Fortescue are still decades away. The Queensland treasury last week released data showing that under the International Energy Agency's (IEA) Advanced Pledges Scenario, it expects Australian metallurgical coal exports will remain steady at around 190mn t/yr until 2030.

"Under the long-term scenarios outlined in the IEA's 2022 World Energy Outlook, it is still expected that international demand should continue to support Queensland's coal exports over coming decades, in particular for the state's metallurgical coal producers," the Queensland treasury's coal report concluded.

By Jo Clarke