metals. metallurgy the extraction of metals from ores by reduction (less reactive metals) by...
TRANSCRIPT
Metallurgy
• the extraction of metals from oresby reduction (less reactive metals)by electrolysis of melt (reactive metals)
• the preparation of metals for use
• the study of the relationship between structures and properties of metals
Roasting
• converting sulphide ore to oxide
2ZnS(s) + 3O2(g) -----> 2ZnO(s) + 2SO2(g)
2CuS(s) + 3O2(g) -----> 2CuO(s) + 2SO2(g)
3FeS2(s) + 8O2(g) -----> Fe3O4(s) + 6SO2(g)
Chemistry of blast furnace
raw materials:
iron ore – several kinds
limestone – calcium carbonate
coke – heated coal
air – to provide the blast
Chemistry of blast furnace – raw materials
iron ore => source of iron
Could be any of the following:
Fe2O3, Fe3O4, FeO,
Ore names: haematite, magnetite, ferrite
Sand impurity - SiO2
Chemistry of blast furnace – raw materials
Limestone (calcium carbonate) is used to remove impurities – it reacts with the sand which is usually found mixed with the iron ore. In the heat of the furnace it decomposes to calcium oxide (lime) and this then reacts with the silicon dioxide to produce calcium silicate (slag)
CaCO3 CaO + CO2
CaO + SiO2 CaSiO3
Production of Copper
Cu2S(l) + O2(g) -----> 2 Cu(l) + SO2(g)
Cu(s) -----> Cu(s)
impure electrolysis pure
Chemistry of Basic Oxygen Furnace
raw materials
pig iron from blast furnace
fluxing agent to remove impurities
alloying agents
Chemistry of Basic Oxygen Furnace
Removal of excess of carbon
C(s) + O2(g) -----> CO2(g)
impurity air
in pig iron