Chapter of Chemistry Metallurgy

Introduction

• Channel: Sir Tarun Rupani
• Dedicated for ICSE board students
• Discussion on Metallurgy chapter
• All subjects covered on the channel
• All contents available for free for you

About Metals

• High melting and boiling points, luster (shine)
• Ductility (converted into thin wires) and malleability (converted into thin sheets)
• First metal used by humans: Copper
• What are metals?
  • Electropostive (electron donors)
  • Found upper in the high activity series
  • Gold, platinum are the least reactive (in native state)

Identification of Metals

• Found in the earth's crust in the form of metal minerals
• Profitable metal extraction called ores
• 118 elements include metals, non-metals, and metalloids
• Special processes for highly active metals like iron

How are metals extracted?

1. Crushing and Grinding

• Ore is crushed to increase the surface area

2. Concentration or Dressing

• Hydraulic Washing Gravity Separation: Difference in gravity and density
• Magnetic Separation: Separation of magnetic and non-magnetic substances
• Froth Flotation: Using a mixture of pine oil and water to lift lighter particles

3. Conversion of Ore to Oxides

• Roasting: Oxidizing
• Calcination: Heating ore in the absence of oxygen

4. Reduction of Oxide to Metal

• Reducing Agents: Use of carbon monoxide, hydrogen
• Electrolytic Reduction: For reactive metals

5. Electrolytic Refining

• Purifying metals
• Examples: Silver, copper, gold

Aluminium Extraction through Hall-Héroult Process

• Aluminium: The most common and cheap metal
• Extracting aluminium from bauxite ore in four steps:
  1. Grinding and heating bauxite
  2. Adding sodium hydroxide
  3. Forming aluminium hydroxide at 50°C
  4. Forming aluminium oxide at 1000°C

About Alloys

• Gold: 24-carat gold is soft
• Iron: Steel (by adding chromium, carbon), stainless steel
• Fusible Alloys: Easily meltable alloys (solder)
• Examples of other Alloys:
  • Brass: Zinc, copper
  • Bronze: Copper, tin, zinc
  • Stainless Steel: Iron, chromium, nickel, carbon
  • Duralumin: Aluminium, copper, magnesium, manganese
  • Type Metal: For printing

Conclusion

• Importance of metallurgy and various methods
• Useful materials available for students for free
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