Direct reduced iron

Iron produced by removing oxygen from ore with a hot reducing gas while the ore stays solid.

• Ore pellets descend through a shaft furnace at about 900–1,000 °C while gas rich in hydrogen and carbon monoxide rises and strips out the oxygen.
• The output is porous 'sponge iron', usually melted with scrap in an electric arc furnace to make steel.
• Most plants run on natural gas and emit roughly half the CO2 of a blast furnace; switching to green hydrogen can cut emissions by over 90%.
• It needs high-grade ore, about 67% iron or more, which is a small share of world supply, and green hydrogen remains expensive.