L1 /
16
CH1012
COPPER SMELTING
• Roasting pyrometallurgy
2CuFeS2(s) + 3O2(g) ® 2FeO(s) + 2CuS(s) + 2SO2(g)
2CuFeS2(s) + 3O2(g) ® 2FeO(s) + 2CuS(s) + 2SO2(g)
CuS(s) + O2(g) ® Cu(l,crude) + SO2(g)
- the sulphide ion is the reducing agent in
the above reaction which is more complex than the written overall reaction suggests.
- the sulphide ion is the reducing agent in
the above reaction which is more complex than the written overall reaction suggests.
• Roasting
involves heating with a gas in
a
furnace to transform the ore into a cmpd.
furnace to transform the ore into a cmpd.
• Electrochemical
purification (electrolysis)
Cu(crude) ® Cu2+ +
2e (anode)
(&
Ni2+ & Fe2+)
Cu2+ +
2e ® Cu(pure) (cathode) ( not Ni & Fe)
- the
precious metal impurities (Ag, Au, Pt) don’t oxidise and pay for the electricity!
D
