Element Rhenium, Re, Transition Metal

Attempts to discover elements 43 and 76 predicted by Mendeleev remained unsuccessful until 1920s when they have been discovered by Walter Noddack and Ida Tacke determined the maim properties of lacking elements. Noddack and Tacke were systematically examined ores and minerals in which the presence of sought-for elements was highly probable. They started in 1922 with their attempts to separate elements 43 and 75 from platinum ore, but since that became too costly, soon continued with other minerals, particularly with the rare-earth ores such as columbite and gadolinite. After 3 years of hard work Noddack and Tacke as well as the Otto Berg succeeded in their attempts in concentrating fractious separated from minerals identifying the new series of 5 lines. It turned out that they belonged to the element number 75. It was named rhenium (Latin for the River Rhine), after the homeland of Ida Tacke.

Rhenium is the rarest and much dispersed trace element. Its average abundance is 7x10^-8 weight %, less than that of any of platinoid or lanthanide. Without taking into consideration crustal abundances of inert gases (much less than that in atmosphere), rhenium is the rarest element with stale isotopes. Rhenium does not form its own ores; it is associated with molybdenum, tungsten, lead, platinum, tantalum, niobium, etc. Rhenium minerals such as dzhezkazganite Pb₄Re₃Mo₃S₁₆ are so rare that have rather scientific than any commercial significance. Rhenium occurs mostly in molybdenite which is deposited in USA, Armenia, Uzbekistan, China Norway, Chile and Germany. Significant amounts of it are also found in granite pegmatites, e.g. in alvite, gadolinite, zircon, columbite, tantalite etc., forming delicately dispersed sulphides. Rhenium is found in platinum and tungsten minerals as well as in meteorites - 0.01 g per ton, which is much more than in the Earth's crust; as well as in cupriferous sandstone and asphalt residue.