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Extraction
Extraction of Metals
Term | Definition |
---|---|
Extraction by electrolysis | potassium, sodium, calcium, magnesium, aluminium |
Extraction by reducing agent-carbon/carbon monoxide | zinc, iron, lead |
What’s in the charge? | Iron ore (haematite = iron oxide and sand), limestone (mainly Calcium Carbonate), Coke (almost pure carbon) |
Stage one: Reactions in the blast furnace | Coke burns, giving off heat, C + O2 = CO2 |
Stage two: Reactions in the blast furnace | Carbon monoxide is made, C + CO2 = 2CO |
Stage three: Reactions in the blast furnace | Iron oxide is reduced, Fe2O3 + 3CO = 2Fe + 3CO2 |
Limestone is for? | reacting with silica, to remove impurities from the haematite, slag at the top is drained off |
Waste gases? | CO2 and Nitrogen |
Extracting Aluminium | bauxite to alumina/white aluminium oxide to electrolysis to usage |
Electrolysis of Aluminium | Alum. gains electrons at the cathode whilst, at the anode, the oxygen loses electrons |