History - Rhenium.de | A Key Metal in Modern High Technology

Discovery

The late discovery of a rare element

Rhenium was discovered in 1925 by the German chemists Ida Tacke, Walter Noddack and Otto Berg as one of the last elements in the periodic table. They identified it in the mineral columbite using X-ray spectroscopy. They were only able to extract a measurable quantity - one gram - from 660 grams of Norwegian molybdenum ore in 1928. According to several sources, the name of the element refers to Tacke's homeland, the Rhineland, and comes from the Latin name of the Rhine, Rhenus.

The existence of the element with atomic number 75 had already been predicted in 1871 by Dmitri Mendeleev, one of the inventors of the periodic table. However, as rhenium is rare and its isolation is complex, decades passed before it could be detected. More recent research indicates that it was probably identified as early as 1908 by the Japanese chemist Ogawa Masataka. However, he considered it to be the still unknown element 43 - the later technetium - and named it Nipponium after its homeland. As this classification later proved to be incorrect and Masataka was unable to replicate his findings, his discovery went unnoticed for a long time.

Ida Tacke-Noddack, AI presentation

Extraction

From research object to critical industrial metal

Shortly after its discovery, rhenium was already being extracted experimentally in small quantities, including in Germany. The 1940s marked the transition to gradual industrial production. During this time, interest in the raw material with its exceptionally high melting point grew, mainly due to military research in the field of high-temperature alloys and aviation. In 1942, a process was developed in the USA in which rhenium was extracted from the dust produced during the roasting of molybdenum ore. This principle still forms the basis for the production of rhenium today.

In addition to the USA, other countries such as Russia were added as producers on a smaller scale over the following decades. In the 1960s, Chile began extracting rhenium at the same time as expanding its copper industry. To date, the South American country has established itself as the world's most important producer of the metal.

Historical areas of application

The aviation industry becomes the most important customer

Turbine blades, symbolic image

After the beginnings of industrial extraction of rhenium, the first niche applications emerged in the 1950s, for example in electron tubes. From the mid-1960s, the metal was increasingly used in high-temperature materials such as rhenium-tungsten and rhenium-molybdenum alloys. These were used in electrical contacts and thermocouples, among other things.

In the 1970s, oil refining became an increasingly important field of application for rhenium. In the form of ammonium perrhenate (NH₄ReO₄), it is used in platinum-rhenium catalysts. In the reforming process, these enable the conversion of crude oil components into higher-quality fuel components for petrol.

From the 1980s onwards, aviation became the most important field of application for rhenium - accounting for the largest share of total consumption. The raw material is added to nickel-based superalloys, which are used to manufacture turbine blades, guide vanes and combustion chamber parts. As an alloy component, rhenium improves the creep resistance of the material. Due to its high melting point of around 3,180 °C, it is particularly suitable for such applications under extreme temperature conditions.