Echoes Within

Lesson Notes: METALS AND NON-METALS

1. Introduction to Minerals and Ores

1.1 Minerals

• Minerals are naturally occurring chemical substances found in the Earth’s crust.

• They are inorganic, solid, and have a definite chemical composition.

• Examples: Quartz (SiO₂), Calcite (CaCO₃), Hematite (Fe₂O₃).

1.2 Ores

• An ore is a mineral from which a metal can be extracted profitably.

• Not all minerals are ores, but all ores are minerals.

• Example:

  • Bauxite → an ore of aluminium

  • Haematite → an ore of iron

Difference Between Minerals and Ores

2. Main Ores of Important Metals

2.1 Ores of Iron

1. Haematite (Fe₂O₃) – main ore

2. Magnetite (Fe₃O₄)

3. Limonite (Fe₂O₃·3H₂O)

2.2 Ores of Copper

1. Copper pyrite (CuFeS₂) – most important

2. Malachite (CuCO₃·Cu(OH)₂)

3. Cuprite (Cu₂O)

2.3 Ores of Silver

1. Argentite (Ag₂S) – main ore

2. Horn silver (AgCl)

3. Silver glance (Ag₂S)

2.4 Ores of Aluminium

1. Bauxite (Al₂O₃·2H₂O) – main ore

2. Cryolite (Na₃AlF₆)

3. Corundum (Al₂O₃)

3. Extraction of Metals from Their Ores (Brief Explanation)

The general process of extracting metals from ores is called metallurgy. It involves several steps:

3.1 Step 1: Mining

• Ores are dug out from the earth through mining.

3.2 Step 2: Concentration of Ore (Ore Dressing)

The unwanted impurities (sand, soil, rocks) are called gangue.
Concentration means removing impurities to get pure ore.

Common methods:

• Gravity separation

• Froth flotation (for sulphide ores)

• Magnetic separation (for magnetic ores like magnetite)

3.3 Step 3: Extraction of Metal from Concentrated Ore

Metal extraction depends on the reactivity of the metal.

A. Extraction of Moderately Reactive Metals

(E.g., iron, zinc, lead)

Method: Reduction of metal oxides using carbon, CO, or other reducing agents.

Example: Extraction of Iron from Haematite

• Iron ore is mixed with coke and limestone and heated in a blast furnace.

• Coke reduces iron oxide to iron.

• Molten iron collects at the bottom and is tapped out.

B. Extraction of Highly Reactive Metals

(E.g., aluminium, sodium, magnesium)

Method: Electrolysis of molten compounds.

Example: Extraction of Aluminium

• Manufacturers dissolve aluminium oxide ($Al_{2}O_{3}$) in cryolite.

• A high-voltage power source passes electricity through the molten mixture.

• Aluminium metal collects at the cathode.

C. Extraction of Less Reactive Metals

(E.g., copper, silver, gold)

Method:

• Roasting of sulphide ores

• Reduction

• Sometimes found in a native (free) state

Example: Extraction of Copper

• Roasting of copper pyrite produces copper oxide.

• Copper oxide is reduced to copper using carbon.

3.4 Step 4: Purification of Metals

• Extracted metals may still contain impurities.

• Purification is done by:

  • Electrolytic refining

  • Distillation

  • Liquation

Example: Pure copper obtained through electrolytic refining.

Conclusion (SEO-Friendly)

Metals and non-metals play a vital role in our daily lives. Understanding minerals, ores, and the main sources of important metals like iron, copper, silver, and aluminium builds a strong foundation in chemistry. A clear idea of the extraction steps helps students succeed in SEE/NEB exams and supports higher-level studies in science.

Practice : 📌 SEE MCQ Quiz – Metal and Non-metal

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