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Chemistry Master Class Notes: Metals & Metallurgy — High-Yield Exam Guide

Metals, Non-Metals & Metallurgy: Complete Chemistry Notes

Part 1: Physical & Chemical Properties of Metals & Non-Metals

Reactivity Series of Metals

Decreasing Reactivity Order: \( \text{K} > \text{Na} > \text{Ca} > \text{Mg} > \text{Al} > \text{Zn} > \text{Fe} > \text{Pb} > [\text{H}] > \text{Cu} > \text{Hg} > \text{Ag} > \text{Au} \)

Part 2: Metallurgy & Extraction of Metals

1. Concentration of Ore:
   • Froth Flotation: For Sulphide Ores (e.g., Zinc Blende \( \text{ZnS} \), Galena \( \text{PbS} \), Copper Pyrites \( \text{CuFeS}_2 \)) using pine oil collector.
   • Calcination vs Roasting:
     Calcination: Heating carbonate ore strongly in absence of air below melting point: \( \text{ZnCO}_3 \xrightarrow{\Delta} \text{ZnO} + \text{CO}_2 \).
     Roasting: Heating sulphide ore strongly in excess of air below melting point: \( 2\text{ZnS} + 3\text{O}_2 \xrightarrow{\Delta} 2\text{ZnO} + 2\text{SO}_2 \).
2. Thermite Process: Reduction of metal oxides using Aluminum powder as reducing agent: \[ \text{Fe}_2\text{O}_3(s) + 2\text{Al}(s) \rightarrow 2\text{Fe}(l) + \text{Al}_2\text{O}_3(s) + \text{Heat} \] Used for on-site welding of railway tracks and broken machine parts.

Part 3: Alloys & Corrosion

Part 4: Industrial Extraction Metallurgy of Iron, Copper & Aluminum

1. Metallurgy of Iron (Extraction in Blast Furnace)

Iron is extracted from its principal carbonate/oxide ores: Hematite (\( \text{Fe}_2\text{O}_3 \)), Magnetite (\( \text{Fe}_3\text{O}_4 \)), and Siderite (\( \text{FeCO}_3 \)).

Charge fed into Blast Furnace top: Calcined Hematite Ore + Coke (fuel & reductant) + Limestone (\( \text{CaCO}_3 \), flux) in 8:4:1 ratio.

Molten iron collected at bottom is Pig Iron (4% Carbon, high brittleness). Remelted with scrap iron to produce Cast Iron (3% Carbon). Purified further in puddling furnace to produce Wrought Iron (0.1–0.25% Carbon, purest commercial iron).

2. Extraction of Aluminum (Hall-Héroult Process)

Purified alumina (\( \text{Al}_2\text{O}_3 \)) extracted from Bauxite via Baeyer's Process is dissolved in molten Cryolite (\( \text{Na}_3\text{AlF}_6 \)) and Fluorspar (\( \text{CaF}_2 \)) at 1220 K to lower melting point and improve conductivity.

• Cathode (Carbon lining): \( \text{Al}^{3+}(l) + 3e^- \rightarrow \text{Al}(l) \) (Liquid aluminum sinks to bottom).
• Anode (Graphite rods): \( 2\text{O}^{2-} \rightarrow \text{O}_2(g) + 4e^- \); Oxygen reacts with graphite anodes: \( \text{C} + \text{O}_2 \rightarrow \text{CO}_2(g) \) (anodes must be replaced periodically).

Part 5: High-Yield Metallurgy & Alloy Question Set

Part 6: Industrial Refining Methods & Metallurgy Summary

Refining of Crude Metals

1. Electrolytic Refining: Used for Copper, Zinc, Silver, Gold.
   Anode: Impure crude metal block.
   Cathode: Strip of pure metal.
   Electrolyte: Aqueous metal salt solution (e.g., \( \text{CuSO}_4 + \text{H}_2\text{SO}_4 \) for copper refining). Impurities drop beneath anode as Anode Mud containing precious metals (Ag, Au, Pt).
2. Zone Refining: For ultra-pure semiconductors (Silicon, Germanium).
3. Mond's Process: For refining Nickel via volatile carbonyl formation: \[ \text{Ni} + 4\text{CO} \xrightarrow{330 \text{ K}} \text{Ni(CO)}_4 \xrightarrow{450 \text{ K}} \text{Ni (Pure)} + 4\text{CO} \]
4. Van Arkel Method: For refining Zirconium (Zr) and Titanium (Ti) using Iodine vapor.

Part 7: Comprehensive Master Metallurgy & Alloy Summary Table

High-Yield Practice Questions & Concept Review

Part 8: Comprehensive Extraction Metallurgy Reactions & Slag Chemistry

Comprehensive Ores & Chemical Formulas Reference Table

Part 9: Refining Methods & Metallurgy Summary Table

Part 10: High-Yield Reactivity & Metallurgy Practice Question Set

Part 11: Summary of Common Alloys & Everyday Chemistry Applications

Below is a handy reference table of industrial alloys, composition percentages, and specific applications for competitive exams:

Frequently Asked Questions (FAQ) & High-Yield Exam Tips