“The pilot plant will be able to reduce fine high-grade iron ore concentrates with Hydrogen to confirm the design basis for an industrial-scale Circored™ plant. Primarly, the pilot plant augments our capability to reduce low-grade iron concentrate fines in larger quantities than what we can do today, for subsequent electric smelting tests with fine DRI for hot metal production. We are convinced of the combination of Circored direct reduction with DRI Smelting as an alternate process route for carbon neutral steelmaking, which can be applied also for low grade iron ores in BF (blast furnace) quality. By providing larger samples of fine, hydrogen reduced direct-reduced iron (DRI) we want to support the development of DRI smelting furnaces,” says Parizat Pandey, Director, Direct Reduced Iron (DRI) at Metso.
Pathway to Green Steel
Commissioning of the plant is expected to take place in the fourth quarter of 2024. Once operational, the 700 mm pilot plant will be able to continuously produce 150 – 200 kg/h of DRI, using 100% hydrogen as the sole reducing agent. The pilot plant will have an integrated pre-heating and reduction section, followed by a gas cleaning and recirculation facility. The investment includes installation of electric heaters in the process, making it an almost zero-carbon-emission plant. The data obtained from the use of electric heaters will be used to scale up the design of industrial heaters capable of running on renewable energy.
The respective pilot plant has originally been built already in the 1980's and was the basis for the successful development and market introduction of the CFB (circulating fluidized bed) technology for coal combustion power plants and alumina calciners. Over the years it was constantly modified and used for the different research projects, for example for the gasification of coal, oil shale or plastic residues or the coal based direct reduction of iron ore.
Metso’s research center in Frankfurt, Germany, has several other fluidized bed pilot plants with a smaller reactor diameter and thus smaller production capacity. With this lab scale pilot plant, Metso has been developing numerous processes for roasting, calcination and reduction of different ores and is performing permanent tests for the design of industrial plants as well as for the basis of performance guarantees
Based on the results from the pilot plant, the first of its kind industrial Circored plant in Trinidad was built, with design capacity to produce 0,5 Mtpa HBI. Worldwide, this facility was the first hydrogen based direct reduction plant for fine ores and produced after the successful construction and commissioning in 1998 already 300,000 tons of high quality HBI (hot briquetted iron), before it was idled mainly due to the non-availability of gas for the hydrogen production.