Grade 12
  1. Solid state  1.1. Classification of solids  1.2. Crystal Lattice and Unit Cell  1.3. Packing Efficiency  1.4. Density of unit cell  1.5. Imperfections in solids (point and line defects)  1.6. Electrical Properties of Solids (Conductors, Insulators and Semiconductors)  1.7. Magnetic Properties of Solids (Diamagnetic, Paramagnetic and Ferromagnetic Materials)
  2. Solution  2.1. Types of Solutions (Homogeneous and Heterogeneous)  2.2. Expressing concentration of solutions (mass %, volume %, molarity, molality, normality, mole fraction)  2.3. Solubility of solids and gases in liquids (Henry's law)  2.4. Raoult's Law and Ideal and Non-Ideal Solutions  2.5. Syndrome properties  2.6. Abnormal molar mass and Van't Hoff factor
  3. Electrochemistry  3.1. Electrochemical cells (galvanic and electrolytic cells)  3.2. Galvanic cell and EMF of the cell  3.3. Standard electrode potential and electrochemical series  3.4. Nernst equation and its applications  3.5. Conductivity and electrolytic cells (specific, molar and equivalent conductivity)  3.6. Kohlrausch's law and its applications  3.7. Batteries (primary and secondary cells)  3.8. Corrosion and its prevention
  4. Chemical kinetics  4.1. Rate of chemical reaction  4.2. Factors affecting the reaction rate (concentration, temperature, catalyst, surface area)  4.3. Order and molecularity of the reaction  4.4. Integrated Rate Equations (Zero, First and Second Order)  4.5. Half-life of a reaction  4.6. Collision theory and activation energy  4.7. Arrhenius equation and its applications
  5. Surface chemistry  5.1. Adsorption and its types (Physicosorption and Chemisorption)  5.2. Catalysis and its types (homogeneous and heterogeneous)  5.3. Colloids and their properties (Tyndall effect, Brownian motion, coagulation)  5.4. Emulsions and gels  5.5. Applications of Colloids
  6. General principles and processes of separation of elements  6.1. Presence of metals and minerals  6.2. Concentration of ores (gravity separation, froth flotation, magnetic separation)  6.3. Extraction of raw metals (roasting, calcination, reduction)  6.4. Thermodynamic and electrochemical principles of metallurgy  6.5. Refining of metals
  7. P-block elements  7.1. Group 15 elements (nitrogen and phosphorus)  7.2. Group 16 Elements (Oxygen, Sulphur and their Compounds)  7.3. Group 17 Elements (Halogens and their Compounds)  7.4. Group 18 Elements  7.5. Properties and Trends in p-Block Elements  7.6. Important compounds of p-block elements (ammonia, phosphine, sulphuric acid, hydrochloric acid)  7.7. Interhalogen compounds and their applications
  8. d-block and f-block elements  8.1. General Properties of Transition Metals  8.2. Properties of Inner Transition Metals (Lanthanoids and Actinoids)  8.3. Lanthanoid and actinoid contractions  8.4. Coordination Chemistry of d-Block Elements
  9. Coordination compounds  9.1. Werner's theory and modern concepts  9.2. Coordination number and type of ligand  9.3. Nomenclature of Coordination Compounds  9.4. Isomerism (geometrical and optical) in coordination compounds  9.5. Bonding in Coordination Compounds (Valence Bond Theory and Crystal Field Theory)  9.6. Stability and applications of coordination compounds in medicine and industry
  10. Haloalkanes and haloarenes  10.1. Classification and nomenclature of haloalkanes and haloarenes  10.2. Physical and Chemical Properties of Haloalkanes and Haloarenes  10.3. Mechanism of Nucleophilic Substitution Reactions (SN1 and SN2)  10.4. Uses and environmental effects (ozone depletion, CFCs)
  11. Alcohol, phenol and ether  11.1. Structure and classification of alcohols, phenols and ethers  11.2. Preparation and properties of alcohols  11.3. Preparation and properties of phenol  11.4. Preparation and properties of ethers  11.5. Chemical Reactions and Uses
  12. Aldehydes, ketones and carboxylic acids  12.1. Structure and nomenclature in aldehydes, ketones and carboxylic acids  12.2. Preparation and properties of aldehydes and ketones  12.3. Chemical reactions in aldehydes, ketones and carboxylic acids (nucleophilic addition, oxidation and reduction)  12.4. Preparation and Properties of Carboxylic Acids  12.5. Chemical Reactions and Uses of Carboxylic Acids
  13. Nitrogen-containing organic compounds  13.1. Amines (classification, structure, basicity)  13.2. Preparation and properties of amines  13.3. Reactions of Amines (Diazotization, Carbylamine Reaction)  13.4. Diazonium salts and their applications in paint industry
  14.1. Carbohydrates (classification and properties)  14.2. Proteins (Structure and Function)  14.3. Enzymes (Mechanism and Function)  14.4. Nucleic acids (DNA and RNA)  14.5. Vitamins and hormones
  15. Polymer  15.1. Classification of Polymers (Addition, Condensation, Copolymers)  15.2. Types of polymerization (free radical, ionic, condensation)  15.3. Important Polymers and Their Uses  15.4. Biodegradable and non-biodegradable polymers
  16. Chemistry in Everyday Life  16.1. Drugs and their classification (analgesics, antipyretics, antibiotics, antacids)  16.2. Chemicals in food and cosmetics (preservatives, artificial sweeteners, antioxidants)  16.3. Cleaning agents and detergents (soaps, synthetic detergents, surfactants)  16.4. Environmental Chemistry (Pollution, Green Chemistry, Sustainable Chemistry)

Grade 12 → General principles and processes of separation of elements ↓


Extraction of raw metals (roasting, calcination, reduction)


Extracting metals from their ores and refining them into usable forms is an essential part of human civilization. Metals are extracted from their ores and refined into usable forms using various methods. This is an important field in chemistry known as metallurgy. The processes involved are roasting, calcination, and reduction. We will look at each step in detail with pictures and examples to ensure clear and comprehensive understanding.

What are ores?

Before delving deeper into the extraction processes, it is essential to understand what ores are. Ores are naturally occurring substances from which metals can be profitably extracted. They are usually oxides, sulphides or carbonates of the metals concerned. The aim of the extraction process is to separate the metal from its combined state in the form of ores into its free form.

Roast

Roasting is a metallurgical process that involves gas-solid reactions at high temperatures. It is a stage of extraction in which the ore is heated in the presence of oxygen. It is used mainly for sulphide ores.

2ZnS + 3O 2 → 2ZnO + 2SO 2

In this example, zinc sulfide (ZnS), a major ore of zinc, reacts with oxygen (O 2) to form zinc oxide (ZnO) and sulfur dioxide (SO 2).

Why roast?

  • Converts sulfides to oxides, making them easier to convert into metals.
  • Helps in removing impurities like water and carbon dioxide.
  • Removes volatile impurities such as SO2 or arsenous gases.

Visual example of the roasting process

Ore O2 product

The diagram above simplifies the process of roasting. The ore is heated and reacted with oxygen present in the atmosphere or added externally, yielding the roasted product.

Cook

Calcination refers to a thermal treatment process in which the ore is subjected to high temperatures in the absence or limited supply of air or oxygen. It is mainly employed to bring about thermal decomposition of carbonate and hydrate ores.

CaCO 3 → CaO + CO 2

In this example, calcium carbonate (CaCO3) undergoes calcination to form calcium oxide (CaO) and carbon dioxide (CO2).

Why calcination?

  • If water molecules are part of the crystal structure, it removes them.
  • Decomposes carbonate ores into oxides.
  • Removes volatile components from the ore.

Visual example of the calcination process

Carbonate Ore Heat Oxide Products

In this illustration, carbonate ore is heated in a calcination process, resulting in the formation of oxide and the removal of gaseous byproducts such as CO2.

Shortage

In metallurgy, the process of reducing an ore to its metallic form is known as reduction. This step is necessary to extract the metal in its pure form after roasting or calcination. Reduction generally involves the use of reducing agents or electrolysis to separate metals from their oxides.

Fe 2 O 3 + 3CO → 2Fe + 3CO 2

In this reaction, iron(III) oxide (Fe 2 O 3) is reduced to iron (Fe) using carbon monoxide (CO) as the reducing agent, forming carbon dioxide (CO 2).

Types of deductions

Chemical reduction

  • Using reducing agents such as carbon, carbon monoxide or reactive metals (Al, Na, Ca).
  • Example: Reduction of copper oxide using hydrogen.
CuO + H 2 → Cu + H 2 O

Electrolytic reduction

  • Used for highly electropositive metals like sodium, potassium.
  • In this, electric current is passed through molten or dissolved salts.
NaCl(l) → Na(s) + 1/2 Cl 2 (g)

Visual example of the reduction process

Oxide Ore RA Metal

This illustration shows the reduction process, in which an oxide ore is reduced by a reducing agent – shown symbolically – to give the metallic form.

Conclusion

The processes of roasting, calcination and reduction are important in extracting metals from their ores. Each method plays a different and important role depending on the type of ore and the desired metal. Roasting deals with sulfide ores, converting them into oxides, while calcination is used mainly to remove volatiles from carbonate ores. Reduction, whether chemical or electrolytic, completes the extraction by converting these oxides into pure metals. Each process takes advantage of thermal or chemical reactions to separate the desired metals from impurities, making possible their practical use in a variety of industrial, technological and everyday applications.

Understanding and mastering these techniques is not only essential for students and chemists, but is also vital in keeping up with technological advancements and metallurgical innovations.


Grade 12 → 6.3


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Concentration of ores (gravity separation, froth flotation, magnetic separation)
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Thermodynamic and electrochemical principles of metallurgy

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Extraction of raw metals (roasting, calcination, reduction)

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