Pure iron is obtained by the reduction of which of the following in the blast furnace?

1. Hematite
2. Magnetite
3. Iron oxide
4. Limonite

Pure iron is produced by reducing iron oxide (Fe₂O₃ or Fe₃O₄) in a blast furnace using carbon. Hematite and magnetite are iron oxide ores, but ‘iron oxide’ is the general term. Limonite is less common. Historically, this process dates to ancient smelting.