Iron- Properties, Uses and Extraction from its Ores | Chemistry for JAMB PDF Download

Iron Extraction from Sulphide and Oxide Ores

• Iron can be extracted from its ores, which include sulphide ores (such as pyrite, FeS₂) and oxide ores (such as hematite, Fe₂O₃) through various methods.
• Sulphide ores are first roasted in the presence of excess air to convert the iron sulphide into iron(II) oxide (FeO) and sulphur dioxide (SO₂). The obtained iron oxide is then reduced to metallic iron using a suitable reducing agent.
• Oxide ores, on the other hand, can be directly reduced to metallic iron by carbon monoxide (CO) in a blast furnace through a process called smelting.

Properties and Uses of Iron and Its Ores

• Iron is a silver-gray metal with a density of 7.86 g/cm³ and a melting point of 1535°C. It is malleable, ductile, and possesses good electrical and thermal conductivity.
• Hematite (Fe₂O₃) is a red ore that is the most common source of iron. It is used in the production of iron and steel, as well as pigments, polishing compounds, and jewelry.
• Magnetite (Fe₃O₄) is a black ore with magnetic properties. It is used in the production of magnets, high-density media for coal preparation, and as a catalyst.
• Pyrite (FeS₂) is a yellow ore commonly known as "fool's gold." It is mainly used in the production of sulfur dioxide (SO₂) for sulfuric acid production and as a source of sulfur for various industrial processes.

Different Forms of Iron and Their Properties

• Cast Iron: Contains 2-4% carbon and small amounts of other elements. It is hard, brittle, and has low tensile strength. It is used in construction, pipes, and automotive parts.
• Wrought Iron: Contains less than 0.2% carbon and has fibrous structures. It is malleable, ductile, and has good resistance to corrosion. It is used in ornamental ironwork and fencing.
• Steel: Contains 0.1-1.5% carbon and various alloying elements. It is strong, ductile, and has excellent tensile strength. It is widely used in construction, manufacturing, transportation, and numerous other industries.

Advantages of Steel over Iron

• Higher Strength: Steel has greater tensile strength and durability compared to iron, making it suitable for structural applications that require high strength.
• Flexibility: Steel can be easily shaped, welded, and formed into various structures, providing flexibility in design and manufacturing processes.
• Corrosion Resistance: Unlike iron, steel can be alloyed with elements such as chromium and nickel to enhance its corrosion resistance, increasing its lifespan and usability in various environments.
• Versatility: Steel can be produced in different forms, including sheets, bars, tubes, and wires, to fulfill a wide range of applications, from construction and machinery to automotive and aerospace industries.