Hafnium (Lat. Hafnium) is a rare metal that is always found in nature together with zirconium. It is renowned in industry for its corrosion resistance, high melting point and ability to absorb neutrons. Hafnium is a good conductor of heat and electricity, with a melting point of 2233 °C and a boiling point of 4600 °C.
Owing to its ability to absorb neutrons, hafnium (chemical symbol Hf) is used in the manufacture of control rods for nuclear power reactors and nuclear submarines. Adding hafnium to various metal alloys improves the corrosion resistance of the resulting materials. The combination of hafnium and titanium is a popular choice in the manufacture of equipment for space programmes.
Hafnium oxide is used as an insulating layer in microchip transistors. However, the quantities of hafnium used in electronics are so small that retail recycling of electronic products to recover this particular metal would be highly unprofitable.
Sources:
https://periodic-table.rsc.org/element/72/hafnium
https://www.britannica.com/science/hafnium
https://en.wikipedia.org/wiki/Hafnium