Aluminum thermite is a mixture of aluminium powder and high melting point metal oxides (such as iron oxide powder) in proportion. When used, it is ignited by adding oxidant, and the reaction proceeds intensely. Aluminum oxide and its monomer are obtained and a large amount of heat is released. The temperature can reach about 2500 C, which can melt the generated monomer. This reaction is called thermite reaction. The thermite reaction principle can be applied in production, such as welding rails. Some metal oxides (such as V2O5, Cr2O3, MnO2, etc.) can be used as thermite instead of iron oxide. When aluminium powder reacts with these metal oxides, enough heat is generated to melt the reduced metal at a higher temperature and separate it from the formed slag to obtain a more pure metal. This method is often used in industry to smelt refractory metals, such as vanadium, chromium, manganese, etc. The use of aluminium when oxidized is exothermic.
As an important component of thermite, metal oxides do not generally refer to all metal oxides, but have a certain range, that is, those refractory metal oxides. These refractory metal oxides emit a lot of heat when they react with aluminium in the mixture, which is also an important condition for the formation of thermite reaction.