Grade 10
  1. Matter and its properties  1.1. States of matter  1.2. Physical and chemical properties of matter  1.3. Classification of substances (elements, compounds, mixtures)  1.4. Changes in Matter (Physical and Chemical Changes)  1.5. Law of conservation of mass and law of definite proportions
  2. Atomic Structure  2.1. Historical development of the atomic model  2.2. Subatomic particles (protons, neutrons, electrons)  2.3. Atomic number, mass number and isotopes  2.4. Electronic Configuration and Energy Levels  2.5. Valency, ion formation and oxidation state
  3. Periodic table  3.1. History and Development of the Periodic Table  3.2. Modern Periodic Law and Periodic Trends  3.3. Groups and Periods in the Periodic Table  3.4. Trends in the Periodic Table  3.5. Metals, non-metals, metalloids and their properties  3.6. Noble gases and their chemical inertness
  4. Chemical bond  4.1. Formation of Chemical Bonds (Octet Rule)  4.2. Ionic Bonding and Properties of Ionic Compounds  4.3. Covalent Bond and Properties of Covalent Compounds  4.4. Metallic bond and its properties  4.5. Molecular geometry and VSEPR theory  4.6. Polarity and dipole moment of molecules  4.7. Intermolecular forces
  5. Chemical Reactions and Equations  5.1. Types of Chemical Reactions  5.2. Writing and balancing chemical equations  5.3. Law of conservation of mass in chemical reactions  5.4. Factors Affecting Chemical Reactions  5.5. Catalysts and their role in chemical reactions  5.6. Exothermic and Endothermic Reactions
  6. Stoichiometry and Chemical Calculations  6.1. Mole concept and Avogadro number  6.2. Molar Mass and Gram-Mole Conversions  6.3. Empirical and molecular formula  6.4. Stoichiometric calculations and chemical yield  6.5. Limiting and Excess Reactants
  7. Acids, Bases and Salts  7.1. Properties and Definitions of Acids and Bases (Arrhenius, Bronsted-Lowry, Lewis)  7.2. pH Scale, pOH, and Indicators  7.3. Neutralization reactions and salt formation  7.4. Strength of Acids and Bases (Strong vs. Weak Acids and Bases)  7.5. Common Acids and Bases in Daily Life  7.6. Salts, their solubility and applications
  8. Metals and Nonmetals  8.1. Physical and chemical properties of metals  8.2. Physical and Chemical Properties of Non-Metals  8.3. Reactivity Series of Metals and Displacement Reactions  8.4. Extraction of metals from ores  8.5. Corrosion, its causes and prevention  8.6. Alloys, their composition and uses
  9. Carbon and its compounds  9.1. Allotropes of Carbon  9.2. Hydrocarbons and their classification (alkanes, alkenes, alkynes)  9.3. Functional groups in organic compounds  9.4. Nomenclature of organic compounds (IUPAC system)  9.5. Isomerism in organic chemistry (structural and geometrical)  9.6. Important organic reactions (combustion, addition, substitution, polymerization)  9.7. Applications of organic compounds in industry and daily life
  10. Environmental Chemistry  10.1. Air Pollution (Sources, Effects and Control)  10.2. Water Pollution (Causes, Effects and Remedies)  10.3. Greenhouse effect and global warming  10.4. Ozone layer depletion and its effects  10.5. Green Chemistry and Its Applications  10.6. sustainable chemistry practice
  11. Thermochemistry  11.1. Heat and Energy Changes in Chemical Reactions  11.2. Exothermic and Endothermic Reactions  11.3. Enthalpy, enthalpy change, and heat of reaction  11.4. Specific heat capacity and calorimetry  11.5. Energy Changes in Combustion Reactions
  12. Electrochemistry  12.1. Electrolytes and non-electrolytes  12.2. Electrolysis and its applications (electroplating, extraction of metals)  12.3. Redox reactions (oxidation and reduction)  12.4. Galvanic cell and electrochemical series  12.5. Corrosion and electrochemical prevention methods
  13. Chemical kinetics and equilibrium  13.1. Rate of chemical reactions and its measurement  13.2. Factors affecting the reaction rate (catalyst, temperature, concentration)  13.3. Reversible and irreversible reactions  13.4. Dynamic equilibrium and equilibrium constant  13.5. Le Chatelier's principle and its applications
  14. Gases and Gas Laws  14.1. Properties of gases and kinetic molecular theory  14.2. Boyle's Law (Pressure-Volume Relation)  14.3. Charles's Law  14.4. Gay-Lussac's Law  14.5. Combined Gas Law and Ideal Gas Law  14.6. Real Gases vs Ideal Gases
  15. Nuclear Chemistry  15.1. Introduction to Radioactivity and Nuclear Reactions  15.2. Types of radioactive decay (alpha, beta, gamma)  15.3. Half-life and applications of radioactive isotopes  15.4. Nuclear fission and fusion reactions  15.5. Nuclear power generation and its environmental impact

Grade 10 → Metals and Nonmetals ↓


Extraction of metals from ores


Introduction to metallurgy

Metals are elements that are generally hard, lustrous, malleable, ductile and good conductors of heat and electricity. But did you know that most of the metals used in our daily lives are obtained through a complex process called metallurgy? The process of extracting metals from their ores and refining them for use is called metallurgy.

What are ores?

Ores are naturally occurring rocks or minerals from which metals can be extracted economically. Not all rocks contain metals in appreciable quantities. Ores usually contain abundant native metals such as oxides, sulfides, silicates, or native copper. Some typical examples of ores include:

  • Hematite: An important ore of iron.
  • Bauxite: The primary ore of aluminum.
  • Chalcopyrite: A major ore of copper.

Stages of metallurgy

Metallurgy generally involves three major stages:

  1. Concentration of ore (or enrichment of ore): This is the initial stage of metallurgy, where the ore is extracted from the ground and concentrated to increase the percentage of metal present in it. This process may involve crushing the ore and then using various methods such as gravity separation, magnetic separation, froth flotation, etc.
  2. Conversion of concentrated ore to metal: The concentrated ore is then converted into the actual metal which is the main step in the extraction of metals. This can be through roasting, calcination or chemical reduction.
  3. Refining of metal: The raw metal obtained from the above process is impure, and refining is done to remove these impurities and obtain pure metal. Common methods include electrolytic refining, zone refining, and vapor phase refining.

Concentration of ore

Concentration of the ore is a critical step that ensures that the ore is pure and concentrated enough to allow effective extraction of the metal. It involves separating the valuable metal-bearing minerals from the waste or gangue.

Fe 2 O 3 + 3CO → 2Fe + 3CO 2

Methods of concentration

Let us discuss some common methods of concentration:

  • Gravity Separation: This method is applicable when the ore particles are heavier than the matrix or gangue. Ore
  • Flotation: Used for sulfide ores, the ore is mixed with water to form a slurry, and air bubbles are passed through the slurry, causing the desired minerals to float. WaterBubble
  • Magnetic Separation: This method is used when the ore or impurities are magnetic. Magnet

Conversion of concentrated ore into metal

The concentrated ore is subjected to various processes to extract the metal. Let's take a look at some of these methods:

  • Roasting: It is a process in which the ore is heated in the presence of oxygen, which removes moisture and volatile impurities.
    2ZnS + 3O 2 → 2ZnO + 2SO 2
  • Calcination: Done by heating the ore very strongly in the absence or limited supply of air, resulting in the decomposition of the carbonate ore.
    CaCO 3 → CaO + CO 2
  • Reduction: It involves the chemical conversion of metal oxide into metal by a reducing agent such as carbon, hydrogen or other active metals.
    Fe 2 O 3 + 3CO → 2Fe + 3CO 2

Metal refining

Finally, the metal extracted from the ore is refined to obtain high purity metal. The refining process depends on the nature of the metal and its use in society.

Common methods of purification

  • Electrolytic refining: The impure metal is made the anode, and the pure metal is made the cathode. When electric current is passed through the electrolyte, the pure metal is deposited at the cathode.
    Cu 2+ + 2e - → Cu
    AnodeCathode
  • Zone refining: Used to purify metals containing impurities with low melting points; a heater moves along a rod of impure metal, melting it and carrying the impurities with it.
  • Vapour phase refining: A method in which the impure metal is converted into its volatile compound, and then decomposed to obtain the pure metal.
    TiCl 4 + 2Mg → 2MgCl 2 + Ti

Conclusion

The extraction of metals from ores is a fascinating journey of chemistry and engineering that transforms rocks into valuable resources. Understanding the basic processes of metallurgy not only explains how metals are prepared for manufacturing, but also sheds light on important stages of human advancement and technological development throughout history.


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Reactivity Series of Metals and Displacement Reactions
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Extraction of metals from ores

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