Extracting Metals
- Created by: beth
- Created on: 31-12-12 14:29
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- EXTRACTING METALS
- A METAL ORE is a rock which contains enough metal to make ETRACTION worthwile
- Most metals need to be extracted using CHEMICAL REACTIONS by either REDUCTION or ELECTROLYSIS
- REDUCTION USING CARBON
- Some metals can be extracted by reduction using CARBON
- When an ore is reduced, OXYGEN is REMOVED
- E.g. Iron Oxide + Carbon > Iron + Carbon Dioxide
- 2Fe2O3 + 3C > 4Fe + 3CO2
- E.g. Iron Oxide + Carbon > Iron + Carbon Dioxide
- The position of the metal in the REACTIVITY SERIES determines whether it can be extracted by REDUCTION WITH CARBON
- Any element BELOW carbon can be extracted by REDUCTION USING CARBON
- This is because carbon can only take oxygen away from metals that are LESS reactiove than itself
- Any element BELOW carbon can be extracted by REDUCTION USING CARBON
- USING ELECTROLYSIS
- ELECTROLYSIS is the BREAKING DOWN of a substance using ELECTRICITY
- It requires a liquid to CONDUCT the ELECTRICITY called the ELECTROLYTE, which are often METAL SALT SOLUTIONS made from the ORE or MOLTEN METAL OXIDES
- The ELECTROLYTE hs FREE IONS which CONDUCT the ELECTRICITY so the whole thing works
- ELECTRONS are TAKEN AWAY by ANODE and GIVE AWAY by CATHODE. As ions GAIN/LOSE electrons, they become ATOMES/ MOLECULES and are released
- Any element ABOVE carbon in THE REACTIVITY SERIES can be extracted using ELECTROLYSIS of MOLTEN COMPOUNDS
- This process is much more EXPENSIVE than reduction using carbon as it uuses A LOT MORE ENERGY
- Copper is PURIFIED by electrolysis even though it is quite EXPENSIVE because copper extracted by REDUCTION USING CARBON is IMPURE and so doesn'y CONDUCT electricity
- COPPER ORES
- COPPER ORES are in SHORT SUPPLY so scientists have found new methods the extrct copper
- BIOLEACHING
- Some bacteria ABSORB COPPER COMPOUNDS THEN PRODUCE SOLUTIONS CALLED LEACHATES, WHICH CONTAIN COPPER COMPOUNDS
- PHYTOMINING
- This involves growing plants in SOIL containing coppper. Plants CAN'T USE/ GET RID of the copper so it gradually BUILDS UP in the LEAVES and can then be HARVESTED, FRIED or BURNED in a FURNACE
- These have a much SMALLER IMPACT on the ENVIRONMENT but are SLOWER
- IMPACTS
- ADVANTAGES
- USEFUL PRODUCTS can be made
- Provides people with JOBS which brings money into the LOCAL ECONOMY
- DISADVANTAGES
- Causes NOISE
- Permanently DAMAGES the LANDSCAPE
- Loss of HABITATS
- ADVANTAGES
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