Unit 17 — Metals | Science & Technology Class 10
Science & Technology · Class 10 · Nepal

Unit 17METALS

From deep underground ores to pure refined metal — explore the complete science of metallurgy, ore types, and extraction processes.

🪨 Ores & Minerals
🔥 Metallurgical Processes
⚡ Electrorefining
✅ Interactive Quiz
Fe
Iron
26
Cu
Copper
29
Al
Aluminium
13
Ag
Silver
47
Core Concepts

Minerals vs Ores

Understanding the key difference between naturally occurring minerals and economically valuable ores.

💎

Minerals

Naturally occurring, inorganic solid substances found in the Earth's crust. Formed through geological processes. They have a definite chemical composition and specific crystal structure. Contain metals in smaller quantities.

All ores are minerals — but not all minerals are ores.

Quartz (SiO₂)Calcite (CaCO₃)FeldsparMicaHematite (Fe₂O₃)
⛏️

Ores

Rocks or minerals containing a high concentration of metals, making it economically viable (profitable) to extract them. Only minerals from which metals can be profitably extracted are called ores.

Economic viability is the deciding factor.

Bauxite → AlHematite → FeChalcopyrite → CuArgentite → Ag
🔷 Mineral
🔶 Ore
Naturally occurring inorganic substance found in the earth's crust
Mineral from which metal can be profitably extracted
May contain metals in small, uneconomical amounts
Contains metals in high, economically viable amounts
All ores are minerals ✓
Not all minerals are ores ✗
Reference Tables

Chief Ores of Important Metals

Select a metal below to view its important ores with chemical formulas.

🔩 Iron
🟤 Copper
⬜ Silver
✈️ Aluminium
S.N.Name of OreChemical FormulaType
1HematiteChief OreFe₂O₃Oxide ore
2MagnetiteFe₃O₄Magnetic oxide ore
3Limonite2Fe₂O₃·3H₂OHydrated ore
4SideriteFeCO₃Carbonate ore
5Iron PyriteFeS₂Sulphide ore
S.N.Name of OreChemical FormulaType
1Copper Pyrite (Chalcopyrite)Chief OreCuFeS₂Sulphide ore
2CupriteCu₂OOxide ore
3Chalcocite (Copper Glance)Cu₂SSulphide ore
4MalachiteCu(OH)₂·CuCO₃Carbonate ore
5Azurite[Cu(OH)₂·2CuCO₃]Carbonate ore
S.N.Name of OreChemical FormulaType
1Argentite (Silver Glance)Chief OreAg₂SSulphide ore
2Horn SilverAgClHalide ore
3Silver Copper Glance(AgCu)₂SMixed sulphide
4Ruby Silver3Ag₂S·Sb₂S₃Complex sulphide
S.N.Name of OreChemical FormulaType
1BauxiteChief OreAl₂O₃·2H₂OHydrated oxide
2CryoliteNa₃AlF₆Fluoride ore
3CorundumAl₂O₃Anhydrous oxide
Metallurgical Processes

How Metals Are Extracted

Click each step in the flowchart below to expand detailed notes and chemical reactions.

1
⛏️
Mining
Extract from earth
2
⚙️
Grinding
Make ore fine
3
🧪
Concentration
Remove gangue
4
🔥
Roasting
Sulphides→Oxides
5
🌡️
Calcination
Carbonates→Oxides
6
🏭
Smelting
Extract metal
7
Electrorefining
Purify metal
⛏️
Mining
Step 1 — Extraction from Earth
Extracting ores from the Earth's crust.

Surface (open-cast): Used for ores near surface — Bauxite, Iron ore.
Underground: Used for ores deep inside — Gold, Copper.
⚙️
Grinding (Crushing)
Step 2 — Making Ore Fine
Mined ore is broken into small pieces, then ground into fine powder.

Equipment used: Crushers, Ball mills, Stamp mills.
Purpose: Increase surface area for easier extraction.
🧪
Concentration
Step 3 — Removing Gangue
Gravity separation: Density difference (gold, tin ore)
Froth flotation: Sulphide ores (ZnS, PbS, CuFeS₂)
Magnetic separation: Magnetic ores (magnetite)
Leaching: Bauxite in NaOH (Bayer's process)
🔥
Roasting
Step 4 — Sulphides to Oxides
Strong heating of sulphide ores in excess air (oxygen) below melting point. Converts sulphides → oxides.
2ZnS + 3O₂ → 2ZnO + 2SO₂
2PbS + 3O₂ → 2PbO + 2SO₂
🌡️
Calcination
Step 5 — Heating Carbonate Ores
Heating ore in absence of air below melting point. Decomposes carbonates → oxides.
CaCO₃ → CaO + CO₂
Al₂O₃·2H₂O → Al₂O₃ + 2H₂O
🏭
Smelting
Step 6 — Extract Metal
Heating ore with a reducing agent (carbon/CO) at high temperature in a blast furnace.
Fe₂O₃ + 3CO → 2Fe + 3CO₂
ZnO + C → Zn + CO
Electrorefining
Step 7 — Purify Metal
Anode = Impure metal (dissolves)
Cathode = Pure metal (deposits)
Electrolyte = Metal salt (CuSO₄ for Cu)
Anode: Cu → Cu²⁺ + 2e⁻
Cathode: Cu²⁺ + 2e⁻ → Cu

🔥 Roasting vs 🌡️ Calcination — Key Differences

🔥 Roasting
🌡️ Calcination
Done in presence of excess air/oxygen
Done in absence or limited supply of air
Used for sulphide ores (ZnS, PbS, CuFeS₂)
Used for carbonate & hydrated ores
Converts: sulphide → metal oxide + SO₂
Converts: carbonate → metal oxide + CO₂
2ZnS + 3O₂ → 2ZnO + 2SO₂
ZnCO₃ → ZnO + CO₂
Interactive Exercise

Multiple Choice Questions

Click an option to check your answer instantly.

Score: 0 / 12
Model Answers

Short & Long Answer Questions

Click any question to reveal the model answer.

Reference

Key Terms & Glossary

Important metallurgical terms and definitions for quick revision.

Unit 17 — Metals · Science & Technology Class 10 · Interactive Study Guide