Metallurgy

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Mineral: A naturally occurring substance containing metal in free state or as compounds (oxides, sulphides, silicates, etc.). Example: Iron is present in 800 minerals. Ore: A mineral containing high …

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The three main steps are: 1. Concentration of ore: Removal of gangue (non-metallic impurities and rocky materials) to increase metal concentration. 2. Extraction of crude metal: Conversion of ore in…

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Balanced equation: 4Au(s) + 8CN⁻(aq) + O₂(g) + 2H₂O(l) → 4[Au(CN)₂]⁻(aq) + 4OH⁻(aq) Explanation: - Gold is converted to soluble cyanide complex [Au(CN)₂]⁻ - Gangue (aluminosilicate) remains insoluble…

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Balanced equation: Al₂O₃(s) + 2NaOH(aq) + 3H₂O(l) → 2Na[Al(OH)₄](aq) Explanation: - Alumina is amphoteric (reacts with both acids and bases) - Sodium hydroxide dissolves Al₂O₃ forming soluble sodium …

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Balanced equation: 2ZnS(s) + 2H₂SO₄(aq) + O₂(g) → 2ZnSO₄(aq) + 2S(s) + 2H₂O(l) Products: - ZnSO₄: Soluble zinc sulphate (remains in solution) - S: Elemental sulphur (solid precipitate) - H₂O: Water …

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Balanced equation: 2PbS(s) + 3O₂(g) → 2PbO(s) + 2SO₂(g) ↑ Other roasting examples: 2ZnS(s) + 3O₂(g) → 2ZnO(s) + 2SO₂(g) ↑ 2Cu₂S(s) + 3O₂(g) → 2Cu₂O(s) + 2SO₂(g) ↑ Why roasting is preferred: 1. Conve…

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Balanced equations: 1. Carbonate ore (calcite): CaCO₃ → CaO + CO₂ ↑ 2. Lead carbonate: PbCO₃ → PbO + CO₂ ↑ 3. Zinc carbonate: ZnCO₃ → ZnO + CO₂ ↑ 4. Hydrated ore: Al₂O₃·2H₂O → Al₂O₃(s) + 2H₂O(g) ↑ 5.

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Balanced equation: Fe₂O₃(s) + 3CO(g) → 2Fe(l,s) + 3CO₂(g) ↑ Alternative forms: Fe₃O₄(s) + 4CO(g) → 3Fe(l,s) + 4CO₂(g) ↑ FeO(s) + CO(g) → Fe(l,s) + CO₂(g) ↑ Reaction mechanism: 1. CO acts as reducing…