METALLURGY
Metallurgy
• The extraction of metals
from their ores and
refining it is known as
metallurgy
Metal urgy
Enrichment of the ore
removal of gangue
Conversion of the ore into suitable form
Physical method
Chemical method
Hydraulic washing
Leaching
froth floation
electromagnetic seperation
Roasting
Calcination
Reduction
Refining
By heating(Hg)
Liquation(Sn,Pb)
By heating with C( Zn ,Fe)
Distil ation (Zn, Hg )
Electrolytic reduction (Na,Mg . . .)
Electrolytic refining ( Cu, Hg ,AU)
ENRICHMENT OF ORE
• Process used for removal of the
“GANGUE”
• GANGUE – Soil, Sand and Earthy
Impurities
Enrichment processes
• Hydraulic washing
Froth Floatation
Electromagnetic
separation
Chemical Method
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Dissolve ore + Hot and Conc. NaOH
Al2O3 + 2NaOH -> 2NaAlO2+H2O
Filter it- add dil HCl
NaAlO2 + 2H2 O + HCl - Al(OH)3 + NaCl
Filter the ppt wash,dry and Ignite
2Al(OH)3 - Al2O3 + 3H2O
Pure Bauxite is obtained
REDUCTION
• Conversion of concentrated ore into a more
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suitable form
Roasting -- Heating the Sulphide ore in
presence of air to form an Oxide ore
2ZnS+3O2  2ZnO + 2SO2
Calcination -- Heating the Carbonate ore
in the absence of air to form an Oxide ore
ZnCO3- ZnO + CO2
Reduction
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Low in the reactivity series ----
Heating ---- e.g..2HgS + 3O2 2HgO +2SO2
2HgO(S) - 2Hg + O2 (g)
Middle in the reactivity series
Heating with C (Smelting)
ZnO + C --Zn + CO
High up in the reactivity series  Electrolytic reduction
REFINING
• LIQUATION:
Used for metals having low M.P. Pb,Sn
Impurity(High M.p.)
Metal
(low M.P.)
Hearth
REFINING
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DISTILLATION
Metals used are Volatile - Hg ,Zn
The impure metal is heated in a retort.
The Pure metal distils over and is
condensed in a receiver.
• The impurities are left behind in the retort
k
• ELECTROLYTIC REFINING
• Metals used are ---Cu,Zn,Sn,Ni,Ag,Au…
CuSO4 +
H2SO4