- Created by: justine_rykiel
- Created on: 06-06-15 15:03
An ore is a rock that contains enough metal or metal compound to make it worth extracting. Ores may have to be concentrated before it is extracted, it also envolves digging up large amounts of rock. This process can produce a large amounts of waste and large impacts on the environment. Whilst most metals are found as compounds in ores, and have to be extracted using chemical reactions, some, less reactive metals can be found as elements and can be removed from rocks physically ( like gold). Metals that are reactive must be removed by using displacement reactions. Displacement reactions involve heating a metal oxide ( ore) with a more reactive metal ( mainly carbon). The reaction is a reduction reaction makes carbon dioxide and the metal element. The method used to extract a metal from its ore depends on its reactivity.
Ores that contain Iron oxide (|||) produce iron. The iron oxide (|||) is reduced in the blast furnace at high temperatures, by using carbon. But the iron produced isn't pure, it contains 96% iron and the rest are impurities, this makes the product brittle and hard so it only has a few uses for cast iron as it is strong when compressed. Removing all of the impurities and carbon makes it pure but now it is too soft to use.
Metal oxides more reactive than carbon must be extracted using electrolysis as it is too expensive to use more reactive metals.
Often, iron is used to make steels. Steels are alloys of iron ( it contains some carbon and other elements). Different alloys can be made for specific uses, this is done by adjusting the amount of carbon and other elements in the alloy, low-carbon steels can be easily shaped, and high-carbon steels are hard. Steels such as stainless steel contain larger amounts of other metals and it resists corrosion. Steels are more useful because they are harder, can be made for specific uses and can resist corrosion.
Copper rich ores can be smelted (heated in the blast furnace) to make copper. Smelting produces impure copper, but this can be purified by electrolysis. Both smelting and electrolysis require large amounts of energy (heating and electricity) so it costs a lot, and has a large impact on the environment.
Copper-rich ores are running out, so scientists are developing new methods for…