Metals in Industry, working with metals
In previous work we considered the role of the blast furnace in extracting iron from its ore.
1) Mixing oxygen with silicon impurities:
2) Decomposition of limestone:
3) Adding these products together:
Titanium is a strong metal used in planes, replacement hip joints, bikes etc. Two steps are used in its manufacture:
Step 1: Convert titanium dioxide (ore) to titanium chloride
Step 2: Displace the titanium using sodium or magnesium:
Aluminium is a fairly reactive metal that doesn’t corrode due to forming a thin layer of aluminium oxide. This explains why greenhouses don’t rust and don’t need to be painted.
A thicker layer of aluminium oxide can be made artificially. There are two stages:
1) Remove the natural layer by placing the aluminium in sodium hydroxide.
2) Use electrolysis on sulphuric acid with the aluminium as the positive electrode. This is called anodising.
Solution containing silver ions