MIDREX

MIDREX is a direct reduction process for producing direct reduced iron (DRI) from iron ore. In this process, iron ore pellets or lump ore are fed to a shaft furnace and reduced by a hot reducing gas, mainly hydrogen and carbon monoxide, derived from natural gas or synthesis gas. The reducing gas moves upward while the ore moves downward, and metallic iron is formed without melting, yielding sponge iron that is discharged at the bottom. The gas is produced in a reformer and conditioned in a gas-purification system to optimize composition and reduce impurities, enabling efficient reuse.

A typical MIDREX plant comprises a reformer to generate reducing gas, a shaft furnace, and gas-cleaning and material-handling sections. The sponge iron produced is commonly used as feedstock for electric arc furnaces or other steelmaking routes, providing flexibility and often lower energy intensity compared with traditional blast furnaces.

MIDREX was developed by Midrex Technologies and has become the most widely installed direct reduction technology worldwide, capable of handling a variety of ore types and gas sources, including natural gas and byproduct gases.