c6.1.2

• iron is extracted from its ore using a large reaction container called a blast furnace.
• • Combustion provides the extreme heat needed for iron extraction
  • Creates initial carbon dioxide, which then reacts further
• In the combustion reaction, the carbon from the coke is oxidized, meaning it gains oxygen to form carbon dioxide. This is a key step that provides the high temperatures needed for the iron extraction process in the blast furnace.
• reduction reaction


  • extracting iron from iron ore
  • Carbon monoxide acts as the reducing agent
  • Removes oxygen from iron oxide
  • Transforms iron from a compound to a pure metal
• important characteristics

  Important characteristics:

  Reduction means losing oxygen

  • Iron oxide loses oxygen
  • Carbon monoxide gains oxygen (becomes oxidized)
  • Occurs at extremely high temperatures (1,500°C)

  Reduction is essentially "cleaning" the iron by removing oxygen, allowing pure iron to be extracted.
• Iron


  • used to make alloy steel which is needed to make bridges,cars, buildings
  • made in the blast furnace using raw materials such as iron ore, coke, limestone and hot hair.
  • the coke is used to make carbon monoxide which is then heated with the iron ore ( iron oxide)
  • IRON OXIDE+ CARBON MONOXIDE--> IRON+CARBON DIOXIDE
  • carbon monoxide is classed as a REDUCING AGENT as it causes iron oxide to be reduced ( loses oxygen)
• reaction happening in blast furnace


  stage 1: coke burns in the hot air, making CO2

  stage2: more coke reduces the carbon dioxide , making carbon monoxide

  stage3: carbon monoxide reduces iron ore to iron around 1500 degrees

  
• 


  coke is used to make the reducing agent

  carbon monoxide and as a fuel to heat the furnace, hot air is blasted into the furnace
• limestone


  • raw material used in blast furnace
  • calcium carbonate
  • to remove impurities
  • iron ore contains impurities, silicon dioxide(sand). In the blast furnace the heat causes the calcium carbonate to decompose into calcium oxide and carbon dioxide
  • calcium oxide reacts with the sand impurities to form a substance called SLAG which can then be removed.
• • due to intense heat in blast furnace, breaking a compound down using heat
  • stage1: Calcium carbonate decomposes in the high temp
  • stage 2: calcium oxide formed reacts with silica from sandy impurities to form calcium silicate.
  • molten calcium sillicate is a slag. It floats on the molten iron and then the iron and slag are sep at the bottom of blastfurnace

  
• phytomining


  • plants growing on contaminated land absorb copper ions as they grow
  • these plants are harvested and burned, producing ash that contains high conc of copper compound
• bioleaching


  • bacteria is mixed in with low-grade ores
  • the bacteria convert the copper into a solution richer in copper compound
  • disadvantage- slow process
• • the aluminium oxide must be made molten for the ions to move through it, so its dissolved in cryolite to lower the melting point
  • cryolite- aluminium compound with a much lower melting point then aluminium oxide
• using cryolite reduces some of the cost in extracting aluminium
• aluminium oxide--> aluminium+oxygen
• to extract aluminium, electrolysis is used
• anode is gradually worn away because the oxygen from the solution reacts with carbon from graphite anode producing CO2 so the anode wears away and needs to be replaced
• aluminium extraction is very expensive beacuse it requires alot electricity
• • when electrode is oxidized in a solution, it is called anode
  • when an electrode is reduced in a solution is it called cathode