Tellurium has been used in metallurgic industry to improve the mechanical properties of steels and other ferrous alloys. It is also used in the form of alloys with copper and lead, used in welding works and in chemical equipment. In the rubber industry, tellurium is used to improve its properties such as its heat resistance. This element can still be used as catalyst. As some of its binary compounds, tellurium can be used in the production of thermoelectrical devices used in power plants and refrigeration. These applications are based on the Seebeck effect, for the current production when heating up a junction of two different metals, and in the Peltier effect that consists of heat transfer by means of an electrical current flow through a metallic junction.