PRIMETALS has successfully tested a pilot-scale process that promises several breakthroughs in the development of greener steel, including the reduction of iron ore using 100% hydrogen and the elimination of a key materials processing step.
Primetals, a joint venture including Mitsubishi and Siemens, began testing its hydrogen-based fine-ore reduction (HYFOR) process in April at a site in Donawitz, Austria. It says the tests have operated successfully, with one run processing around 800 kg of iron ore. The pilot trials are expected to run for at least two years to test various ores and optimise the process for scaleup.
Decarbonisation is a major challenge for the steel sector, where fossil carbon sources conventionally used for both heating and chemical reduction produce emissions. Chris McDonald, CEO of the Materials Processing Institute (MPI), said several players are looking to use hydrogen as a replacement reducing agent. These include the Hybrit project in Sweden, and HBIS in China, which plans to commercialise a hydrogen reduction process later this year – but one that is expected to ramp up to only use 70% hydrogen.
“What we can see here is a pilot plant that is using 100% hydrogen so that’s innovative,” McDonald said about Primetals. “They are right to be excited about this new technology,”.
“They are also using iron ore fines without an agglomeration step. So that takes out a whole area of plant. Usually, the feed is in a pelletised format…they are going to use the fines directly. That removes a mechanical processing step early in the process so that’s going to be easier from a material handling perspective.”
Primetals plans to commercialise its direct reduction plant as modular design, so it’s available to make direct-reduce iron (DRI) for all sizes of steel plants. DRI is typically fed into electric arc furnaces along with scrap steel, but McDonald says DRI reduced by hydrogen could also be used to help decarbonise other steel flow schemes.
“You could imagine a transitionary phase where the DRI is charged into blast furnaces…an advantage of doing that is you can reduce carbon dioxide emissions in your blast furnaces and reduce the amount of coke you need. You might be able to close coke ovens. A steel company that’s trying to make the transition from blast furnaces to electric arc furnaces could install the DRI plant, use the DRI in their blast furnace, gradually reduce their emissions, and then make the switch to the EAF to eliminate 85% of their emissions.”
The HYFOR plant consists of a preheating-oxidation unit, a gas treatment plant and a reduction unit. Primetals said it will also look to add a hot briquetting testing facility to produce hot briquetted iron (HBI) from DRI, which helps improve the stability of the product for shipping.
Catch up on the latest news, views and jobs from The Chemical Engineer. Below are the four latest issues. View a wider selection of the archive from within the Magazine section of this site.