Mazut is a heavy fossil fuel produced as a by-product of crude oil refining. It is one of the cheapest fuels for large industries due to its heavy hydrocarbon compounds and high sulfur content. Mazut is usually used in industrial sectors that require a lot of thermal energy.

Mazut is generally divided into two main types: industrial mazut and domestic mazut. Industrial mazut, which is usually used in large industries such as power plants, cement factories and petrochemical plants, has a high viscosity and a higher sulfur content. Due to its high melting point, this type of mazut must be heated before use in order to burn easily and produce energy.

Domestic mazut has less sulfur than industrial mazut and is mainly used to heat buildings and provide energy in domestic heating systems. This type of mazut is usually further refined to produce fewer pollutants.

Mazut is also sometimes used in the transportation industry, especially in ships and some heavy machinery that require a fuel with high thermal energy. However, due to its high content of environmental pollutants, the use of mazut faces restrictions in some developed countries.

Finally, due to the pollution of mazut and its negative effects on the environment, some countries are looking to replace it with cleaner and renewable fuels.