Iron And Steel

Iron and Steel Learning objectives: •Know how iron oxide is reduced. •Know the advantages of steel over iron. Unscramble the following words: IN OR SENILE TOM CUE RED A CRAB FELT SUN (two words) BACON INDEX ROOM (two words, a gas)

Blast furnace animation 3. Complete the labels on your diagram 4. Write balanced equations with state symbols for a) Carbon reacting with oxygen to form carbon dioxide. b) Carbon dioxide reacting with carbon to form carbon monoxide. c) Carbon monoxide reacting with iron ore to form iron and carbon dioxide. Carbon – C Carbon monoxide – CO

Carbon dioxide – CO2 Iron Oxide – Fe2O3

C [s] + O2 [g] → CO2 [g] CO2 [g] + C [s] → 2CO [g] Fe2O3 [s] + 3CO [s] → 2Fe [l] + 3CO2 [g]

Why is limestone used? • The main impurity in the iron is sand (Silicon dioxide, SiO2) • In the furnace, the limestone undergoes thermal decomposition to form calcium oxide and carbon dioxide: CaCO3 → CaO + CO2 The calcium oxide reacts with the sand to form calcium silicate (slag). CaO + SiO2 → CaSiO3

• The slag floats on top of the molten iron at the bottom of the furnace. • It is used for road foundations and railway track ballast.