rhenium metal is a truly rare element. Its content in the earth's crust is smaller than all rare earth elements, only larger than protactinium and radium. Plus it does not form fixed minerals and is usually associated with other metals. This makes it the last element found in nature.

The scope of application of rhenium metal:
1. Rhenium is mainly used as a catalyst in the petroleum industry.
2. Rhenium has high electron emission performance and is widely used in radio, television and vacuum technology.
3. Rhenium metal has a very high melting point and is a major high-temperature instrument material. At the same time, rhenium-containing alloys are also used in the manufacture of heat-resistant parts of aero-engines, and about 80% of rhenium in the world is used in the production of aero-engines.
4. Rhenium and rhenium alloys can also be used as electronic tube components and ultra-high temperature heaters to evaporate metals.
5. The tungsten-rhenium thermocouple does not soften at 3100°C, adding 25% rhenium to the tungsten or molybdenum alloy can increase the ductility. Rhenium is used as a high-temperature coating on rockets, and rhenium is required for spacecraft instruments and high-temperature components such as heat shields, arc discharges, and electrical contactors.
6. Rhenium metal and its alloys can be used to make fountain pen tips and high temperature thermocouples. It can be used as a catalyst in the chemical industry such as alcohol dehydrogenation and ammonia synthesis. Alloys containing rhenium can withstand high temperatures. Because rhenium is scattered and expensive, its practical application has yet to be developed.