Metals & Ores
Chemistry · धातुएं और अयस्क
📋Quick Overview
Metals are elements that are generally shiny, malleable, ductile, and good conductors. Non-metals are generally dull, brittle, and poor conductors. Ores are naturally occurring minerals from which metals can be extracted profitably. The extraction of metals involves three steps: Concentration of ore, Reduction to metal, and Refining.
📖Metals vs Non-Metals — Properties
📖Reactivity Series of Metals
- •Most reactive to least reactive: K > Na > Ca > Mg > Al > Zn > Fe > Ni > Sn > Pb > [H] > Cu > Hg > Ag > Pt > Au
- •Metals above hydrogen displace H₂ from dilute acids
- •More reactive metal can displace less reactive from its salt solution
- •Gold (Au) and Platinum (Pt) are the LEAST reactive (noble metals)
📖Important Ores — Master Table
| Metal | Ore Name | Chemical Formula |
|---|---|---|
| Aluminium (Al) | Bauxite | Al₂O₃·2H₂O |
| Aluminium (Al) | Corundum | Al₂O₃ |
| Iron (Fe) | Haematite | Fe₂O₃ |
| Iron (Fe) | Magnetite | Fe₃O₄ |
| Copper (Cu) | Copper pyrite (Chalcopyrite) | CuFeS₂ |
| Copper (Cu) | Malachite | Cu(OH)₂·CuCO₃ |
| Mercury (Hg) | Cinnabar | HgS |
| Zinc (Zn) | Zinc blende (Sphalerite) | ZnS |
| Zinc (Zn) | Calamine | ZnCO₃ |
| Lead (Pb) | Galena | PbS |
| Tin (Sn) | Cassiterite | SnO₂ |
| Silver (Ag) | Argentite | Ag₂S |
| Gold (Au) | Calaverite | AuTe₂ |
| Sodium (Na) | Rock Salt | NaCl |
| Calcium (Ca) | Limestone | CaCO₃ |
📖Extraction of Metals — Steps
- •Step 1: Concentration/Enrichment of ore — remove impurities (gangue). Methods: gravity separation, froth flotation, magnetic separation
- •Step 2: Reduction — Convert ore to metal. Low reactivity (Cu, Hg): just heating. Medium (Zn, Fe): carbon reduction. High (Na, Al): electrolysis
- •Step 3: Refining — Purify the metal. Most common method: Electrolytic refining
- •Aluminium extracted by Hall-Heroult process (electrolysis of Al₂O₃ in cryolite Na₃AlF₆)
- •Iron extracted in Blast Furnace from haematite using coke (carbon)