C6.1.7 Extracting Iron

Question 1

Iron ore

Answer 1

• iron ore = haematite, contains iron (lll) oxide
• coke = mostly carbon, made heating coal in absence of air
• limestone = used to purify iron

Question 2

What is it?

Answer 2

Iron is extracted from its ore using a large reaction container - blast furnace
Can produce around 10,000 tonnes of iron per day
Hot air added to bottom of blast furnace

Question 3

How many stages?

Answer 3

Three

Question 4

Stage one in blast furnace

Answer 4

Coke burns in hot air making carbon dioxide

C (s) + O2 (g) —> CO2 (g)

Question 5

Stage 2 in blast furnace

Answer 5

More coke reduces the carbon dioxide —> carbon monoxide

C (s) + CO2 (g) —> 2CO (g)

Question 6

Stage three in blast furnace

Answer 6

Carbon monoxide reduces iron (lll) oxide to iron @ 1500

3CO (g) + Fe2O3 (s) —> 3CO2 (g) + 2Fe (l)

Question 7

What is at bottom?

Answer 7

Slag = molten calcium silicate
Floats on molten rock
Both iron + slag removed separately at bottom of blast furnace