Extraction of iron explained
Extraction of Iron from Hematite
Introduction to Iron Extraction
- The discussion begins with an overview of iron extraction, emphasizing the need to understand the composition of iron ore, primarily hematite (iron(III) oxide) mixed with silicon dioxide (silica).
Blast Furnace Overview
- The extraction process occurs in a blast furnace, which is heated from the bottom where hot air is pumped in. Waste gases exit from vents at the top.
- Key raw materials introduced into the blast furnace include carbon (usually in the form of coke), hematite, and limestone (calcium carbonate). Molten iron and slag are extracted from the bottom.
Reactions in the Blast Furnace
- Five significant reactions occur within the blast furnace:
- Reaction 1: An exothermic reaction between carbon and oxygen forms carbon dioxide.
- Reaction 2: An endothermic reduction reaction where carbon dioxide reacts with carbon to produce carbon monoxide.
- Reaction 3: A redox reaction where iron(III) oxide is reduced by carbon monoxide to yield elemental iron while oxidizing CO to CO₂.
- Reaction 4: Thermal decomposition of calcium carbonate produces calcium oxide and carbon dioxide.
- Reaction 5: A neutralization reaction between calcium oxide and silicon dioxide results in calcium silicate.
Quiz on Impurities and Raw Materials
- A quiz question identifies silicon dioxide as the impurity found in hematite, also known as sand.