Element 75 · Transition Metal
Rhenium
Rhenium is one of the rarest stable elements — used in jet engine superalloys and refinery catalysts.
Element Facts
SYMBOL
Re
ATOMIC NO.
75
ATOMIC WEIGHT
186.21
CATEGORY
Transition Metal
PERIOD
Period 6
GROUP
Group 7
Historical Uses
Rhenium was the last stable naturally occurring element to be discovered. Mendeleev had predicted its existence as "eka-manganese" in 1871, but it eluded discovery for over 50 years. In 1925, German chemists Ida Noddack, Walter Noddack, and Otto Berg detected rhenium spectroscopically in platinum ore and columbite. They named it after the Rhine river (Rhenus in Latin). Isolating a visible quantity — one gram — required processing 660 kg of molybdenite ore.
Rhenium's discovery came with a controversial companion announcement: the Noddacks also claimed to have found element 43, which they named masurium. This claim was later disputed and element 43 (technetium) was not confirmed until its artificial synthesis in 1937.
In the early 20th century, rhenium was used in electrical contacts and filaments. Its most critical modern application emerged in the 1960s: rhenium is added in small quantities (3–6%) to single-crystal nickel superalloys used in jet engine turbine blades, dramatically improving high-temperature strength and creep resistance. Today, jet engines consume the majority of global rhenium production.
Overview
Rhenium is element 75, the second-densest element after osmium and one of the rarest in the Earth's crust. The last stable element to be discovered (1925).
Current Uses
Rhenium-bearing nickel superalloys for jet engine turbine blades — about 70% of rhenium production goes to aerospace. Petroleum reforming catalysts (with platinum) for converting naphtha to high-octane petrol. High-temperature thermocouples.
Not Commercially Viable for Scrap
Why QuickStop Metals doesn’t buy Rhenium:
Rhenium recovery from spent jet engine components and refinery catalysts is highly specialist — handled by precious metal refiners. The metal is too dilute in finished products and too valuable for general scrap operations.
Price Context
Rhenium metal trades at $2,000–4,000/kg depending on grade.