STEELMAKING: Hydrogen-based process for fine iron ore reduction

Finding new solutions to decarbonize the steelmaking value chain is a must for the industry to become fossil-free and to help limit global warming to 1.5°C. To support the efforts, Metso Outotec is introducing the next generation of its Circored process for the direct reduction of iron ore fines. The game-changing process uses hydrogen as a reducing agent instead of CO produced from fossil fuels, allowing the iron and steel industry to efficiently tackle the decarbonization challenge.

The flexible Circored process produces highly metalized DRI (direct reduced iron) or HBI (hot briquetted iron) that can directly be used as feed material in electric arc furnaces for carbon-free steelmaking.

The Circored process is based on the extensive fluidized bed knowledge and experience developed and applied over decades in hundreds of plants for different applications. The process applies a two-stage reactor configuration with a circulating fluidized bed (CFB) followed by a bubbling fluidized bed (FB) downstream.

The typical plant capacity is 1.25 Mt/y per line. Two or more lines can be combined using joint facilities and utility areas. In stand-alone plants, the produced DRI is briquetted to HBI to enable further handling and safe transport. 

If a Circored plant is integrated into an existing steelmaking facility, energy efficiency can be further increased by direct hot feeding of the DRI to an electric arc furnace.

As a general rule, the Circored process can handle feeds with a particle size of up to 2 mm. However, depending on the decrepitation behavior, particle sizes of up to 6 mm are possible. For processing ultrafine (< 50 µm) ores or process reverts like scrubber dust, Metso Outotec has patented a simple microgranulation process.

CIRCORED PROCESS BENEFITS IN BRIEF

• No fossil fuels required for reduction of fines, 100% hydrogen based
• Energy-intensive and costly pelletizing step is eliminated
• HBI or DRI can be fed directly to an electric arc furnace, improving energy efficiency
• Proven performance in industrial-scale demonstration plant using established fluidized bed process