Applications of oxide displacement reactions
One of the most common applications of a thermit oxide displacement reaction is between aluminium and iron (III) oxide.
What early chemists found was that if you mixed aluminium with iron (III) oxide (a naturally occurring ore) you get a very intense reaction known as a thermit reaction. A thermal emittance (thermit) is an extremely exothermic (gives out heat) reaction.
The heat produced by this thermit reaction is used to weld railway lines.
A thermit reaction requires a lot of heat to begin but once it is started the reaction is very violent and gives out an even greater amount of heat. Thermit reactions are often started with a blow torch or by burning a strip of magnesium ribbon (which burns at a high temperature) placed in the thermit mixture.
The reaction you get is:
|Iron (III) oxide||+||Aluminium||→||Aluminium oxide||+||Iron|