Aluminothermic process

“The aluminothermic process is a process that creates molecularly perfect welds by means of a chemical reaction.

The KLK weld brand with more than 50 years of experience in solutions for safety in electrical installations and its KLKweld family for welding in grounding projects is based on the use of a technique in the form of a chemical reaction that not only creates robust and durable joints over time, but also provides an extra material creating an alloy with a higher resistivity than the primary materials… How? ….

The answer is based on the properties of aluminium, which has a great affinity for oxygen, with which it combines to form the oxide, Al2O3. This is a very exothermic reaction in which a large amount of heat is given off.

This is why aluminium powder burns violently at high temperatures and can also reduce the oxides of many metals (except those of the alkali and alkaline earth metals).

This process, called aluminothermia or aluminothermic reaction, is used to obtain various metals, such as manganese, molybdenum, tungsten, chromium, etc., and is also the basis for aluminothermic welding, where the metal obtained in the reaction acts as a filler metal in a welding process. Once the reaction has started, it is self-sustaining due to the heat given off.

• For example, in the case of ferric oxide:

Fe₂O₃ + 2 Al → Al₂O₃ + 2 Fe + Calor,

a temperature of around 3000 ºC is reached, so the iron comes out molten. This process is used to make welded joints between the steel rails of the railway.

• And for example, in the case of cupric oxide:

3 CuO + 2 Al → 3 Cu + Al₂O₃ + Calor´,

temperatures of over 2000 ºC are reached, so the copper also comes out molten. This process is used to make soldered electrical connections between copper conductors.