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METALLURGY PowerPoint Presentation

METALLURGY

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METALLURGY

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  1. METALLURGY

  2. Metallurgy • The extraction of metals from their ores and refining it is known as metallurgy

  3. ENRICHMENT OF ORE • Process used for removal of the “GANGUE” • GANGUE – Soil, Sand and Earthy Impurities

  4. Enrichment processes • Hydraulic washing

  5. Froth Floatation

  6. Electromagnetic separation

  7. Chemical Method • 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

  8. REDUCTION • Conversion of concentrated ore into a more 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

  9. Reduction • 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

  10. REFINING • LIQUATION: Used for metals having low M.P. Pb,Sn Impurity(High M.p.) Metal (low M.P.) Hearth

  11. REFINING • 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

  12. k • ELECTROLYTIC REFINING • Metals used are ---Cu,Zn,Sn,Ni,Ag,Au… CuSO4+ H2SO4