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Where do metals come from?

Where do metals come from?. objectives. Most metals are found as chemical compounds (‘minerals’) in rocks Rocks containing significant amount of particular minerals are called ores How a metal is extracted from its ore depends on that metal’s position in the reactivity series

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Where do metals come from?

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  1. Where do metals come from?

  2. objectives • Most metals are found as chemical compounds (‘minerals’) in rocks • Rocks containing significant amount of particular minerals are called ores • How a metal is extracted from its ore depends on that metal’s position in the reactivity series • To some extent our human history is closely tied to the history of metal extraction

  3. Much metal around?

  4. Much metal around?

  5. How easily a metal can be obtained depends on its reactivity… potassium sodium lithium calcium magnesium aluminium zinc iron lead copper silver gold

  6. Gold is so unreactive that it can be found ‘native’ in the ground

  7. Silver is also to be found in metallic form but you cant really pan for silver, it’s mined

  8. Europe always had a lot of silver mines so it developed an economy based on silver coins

  9. The blue colour is caused by the mineral copper carbonate

  10. Copper, or bronze, reacts with CO2 over time to give a coating of copper carbonate, often called ‘verdigris’ Bronze is an alloy of copper and tin, stronger than pure copper

  11. This is a rock called malachite. It contains significant amounts of the mineral CuCO3. A rock containing significant amounts of a metal compound is called an ore Malachite is an ore, from which we can extract copper

  12. This ore, cassiterite, contains tin oxide. It is from this ore that tin is extracted. Tin was obtained as long ago as copper was, back in an era of human history known as…

  13. The Bronze Age From about 2000BC

  14. In 776 BC… What would be the most valuable metal? Second most valuable? Third most valuable?

  15. Most metals are found as compounds ‘minerals’ in rocks. Rocks containing a significant amount of mineral are called ores. Many metals are extracted from their ores by heating them with carbon.

  16. Bauxite Al2O3 Haematite Fe2O3 Galena PbS Cinnabar HgS Malachite CuCO3 Cassiterite SnO2 Olivine MgSiO4 Sphalerite ZnS

  17. Chemistry changes the world (early example)… About 500BC the Iron Age came to Europe when the techniques of smelting were learned. Iron ore is heated with charcoal in a furnace. Iron is much stronger than bronze, you get wheels, saws to cut down trees, and stronger weapons with iron.

  18. This rock contains a significant amount of iron oxide (that’s what gives it the rusty colour) It is often called simply ‘iron ore’.

  19. Reaction of lead oxide with carbon LEAD OXIDE + CARBON  LEAD + CARBON DIOXIDE PbO2 + C  Pb + CO2 LOST OXYGEN - REDUCTION GAINED OXYGEN - OXIDATION

  20. The Blast Furnace 2Fe2O3 + 3C  4Fe + 3CO2 Iron oxide is reduced by carbon into iron metal

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