To get iron from iron oxide, you need to heat the iron oxide with carbon, typically in the form of coke, in a blast furnace. This process is a crucial step in steelmaking.
The Blast Furnace Process
The primary method for extracting iron from its ore involves a blast furnace. Here's a breakdown of the process:
Inputs
- Iron Oxide Ore: The raw material containing iron combined with oxygen.
- Coke: A form of carbon derived from coal, which acts as a reducing agent and fuel.
- Limestone (Optional): Used as a flux to remove impurities.
Process
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Roasting: Crushed iron oxide ore and coke are roasted together.
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Heating: The mixture is heated in a blast furnace. Temperatures can reach up to 1,200 °C.
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Reduction: At high temperatures, carbon (from coke) reacts with the oxygen in the iron oxide. This reaction strips the oxygen from the iron oxide, leaving behind molten iron.
Step Description Temperature (°C) Roasting Crushed ore and coke are mixed. Variable Heating The mixture is heated in a blast furnace. Up to 1,200 Reduction Carbon reacts with oxygen in iron oxide, producing iron and carbon dioxide. High
Chemical Reaction
The core chemical reaction can be simplified as follows:
- Iron Oxide + Carbon → Iron + Carbon Dioxide (CO2)
Outputs
- Molten Iron: The primary product, which is further processed into steel.
- Slag: Waste material formed from impurities and the flux.
- Carbon Dioxide (CO2): A byproduct of both the burning of coal to heat the furnace and the reactions that strip oxygen from the ore.
Environmental Considerations
- The process of extracting iron from iron oxide is a significant source of CO2 emissions.
- Both the burning of coal (coke) and the chemical reduction of iron oxide contribute to these emissions.
