Transcript Slide 1
Extraction of Iron As we have already discussed, carbon can be used to extract any metal found below it in the reactivity series. Potassium Sodium Magnesium Aluminium Carbon Zinc Iron Tin Lead Copper These metals are more reactive than carbon so can’t be extracted. These metals are less reactive than carbon so can be extracted. Since iron falls into this category then carbon can be used to extract iron from iron ore. A giant blast furnace is used to extract iron from its ore. The following raw materials are used: • iron ore this is mainly a substance called haematite or iron (III) oxide – Fe2O3 • coke this is the carbon – it is made from coal • limestone used to remove acidic impurities e.g. sand • air this reacts with the coke The Blast Furnace iron ore, coke and limestone waste gases 1500° C hot air molten slag molten iron Reactions in the Blast Furnace 1. Coke burns in air: coke + oxygen carbon dioxide The carbon dioxide then reacts with more coke: + carbon dioxide 2. Thecoke carbon monoxide REDUCES iron carbon oxide tomonoxide iron: iron oxide + carbon monoxide Fe2O3 + 3 CO iron + carbon dioxide 2 Fe + 3 CO2 or The carbon (coke) REDUCES iron oxide to iron: iron oxide + carbon Fe2O3 + 3 C iron + carbon monoxide 2 Fe + 3 CO Limestone reacts with any acidic impurities in the blast furnace e.g. silicon dioxide in sand to produce a substance called SLAG. The slag is used for road-making.