a brief history of metal

History of discovery

Praseodymium is a soft, malleable, silvery-yellow metal. It belongs to the lanthanide group of the periodic table of elements. It reacts slowly with oxygen: upon contact with air, it forms a green oxide, which does not protect it from further oxidation.

The history of the discovery of praseodymium included a chain of errors. In 1839, the Swedish scientist Karl Mosander noticed that the previously discovered cerium earth was heterogeneous.

He named the substance isolated from it lanthanum earth. And in 1841 he managed to isolate a new substance from the latter. Due to the exceptional similarity of the properties of these lands, the newcomer was given the name Didim – “double” or “twin” translated from Greek.

However, in 1879, the French chemist Lecoq de Boisbaudran showed that didymium was heterogeneous and isolated a new element from it – samarium. It further turned out that the spectrum of didymium depends on the mineral from which it was isolated. In 1882, Boguslav Brauner of Prague discovered another oddity of didyme: its atomic weight also depended on the original mineral. Thus, it became finally clear that there was no element of didyme, but Boguslav Brauner was unable to divide it into its components.

The Austrian Auer von Welsbach, a specialist in rare earth elements, got lucky in 1885. He reacted didyme with nitric acid and obtained its crystalline salt. After hundreds of fractional recrystallization operations, each of which lasted two days, the output was crystals of two salts – greenish and pink. He called the metal forming the first one praseodymium – from “prasios didymos” or “green twin”. The second salt was attributed to the “new twin” – neodymium. Pure praseodymium was obtained in metallic form only in 1931.

Consumption

The main thing is permanent magnets (wind, electric and auto generators), there is even a commercial product on the world market of rare earth metals – didymium, a mixture of neodymium and praseodymium.

Praseodymium compounds are used to color glass and enamel (for example, green headlamp lenses in lighting technology).

Praseodymium is used in alloys with magnesium to produce a high-strength metal for aircraft engines.

Glass containing praseodymium is used to make glasses that protect the eyes of welders from ultraviolet radiation.

Praseodymium supercapacitors are considered indispensable for energy systems. They are also trying to incorporate praseodymium into fuel cells.

But the most promising area for praseodymium is quantum computers.

Extraction from the subsoil, direct and secondary

Praseodymium is obtained by processing polymetallic ores and man-made refuse/waste containing rare earth elements.

According to data The world's most authoritative observer of the Earth's resources, the US Geological Survey, reserves of REE in the subsurface amount to 110 million tons in oxide equivalent.

The leaders in geological reserves are, million tons in oxide equivalent:

According to estimates by the Russian Mining Industry Association, the total reserve of rare earths in Russia is 20.6 million tons.

Mining of REE is estimated at the end of 2023 at 350 thousand tons, including China – 240; USA – 43; Burma – 38; Russia – about 3, that is, less than 1%. There are no exact statistics on praseodymium.

Praseodymium is isolated from the group of rare earth elements by liquid extraction with tributyl phosphate from an acidic aqueous medium. The metal is obtained by the metallothermic reduction of anhydrous halides, usually calcium thermia of chlorides or fluorides. Purification is carried out by vacuum distillation.

Some states have praseodymium in government reserves, for example, in the United States at the beginning of 2024 – about 70 tons.

Patent aspect of praseodymium

The Google.Patents portal lists 100,000 documents for the word Praseodymium. There are no leaders among patent holders; patents are scattered among hundreds of industrial companies. Top 7 looks like this:

General Electric Company – 3.6%;
Engelhard Corporation — 1.4%;
Minnesota Mining And Manufacturing Company (3M) – 1.1%;
Samsung Electronics Co., Ltd. – 1.1%;
Grirem Advanced Materials Co. Ltd (有研稀土新材料股份有限公司) – 1.0%;
Toyota Jidosha Kabushiki Kaisha – 0.9%;
General Motors Corporation – 0.9%.

The first rows are occupied by transnational electrical and automotive companies from the USA, Japan, South Korea and China. The most active company is the famous GE with almost a century and a half history, which is not surprising, since praseodymium is widely used, as we wrote above, in the same generators.

The leading topics of inventions are:

chemical and physical process (B01J – 27%);
separation of substances (B01D – 18.1%);
ceramics (C04B – 13%);
miscellaneous equipment (Y02T – 13%);
enviroment protection (Y02P – eleven%);
semiconductor devices (H01L– 10%);
materials not classified in other subclasses (C09K – 10%);
miscellaneous equipment (Y10T – 9%);
inorganic chemistry (C01P – 8%);
reduction of greenhouse gas emissions (Y02E — 7%);
coatings (C23C – 7%).

In the domestic FIPS database for “praseodymium” the abstract lists 218 Russian Federation patents for inventions, of which 97 are valid.

In the “process technologies, B” section there are 22 patents, mainly for magnets and catalysts. Thus, the FSUE “VIAM” patent for invention No. 2537947 relates to the field of powder metallurgy, in particular to magnetic material containing praseodymium, iron, cobalt, boron, copper and other elements.

In the section “chemistry and metallurgy of praseodymium, C” – 82 patents (partially duplicating the previous section) – from hydro- and pyrometallurgy of dysprosium compounds to a variety of metal, ceramic, glass and composite substances – for magnets, catalysts and other products, including mechanical engineering.

In the “electricity H” section there are 9 patents with praseodymium – on magnetic materials and electrochemical devices. Patent No. 2812650 “Three-layer solid electrolyte membrane of medium-temperature SOFC” enshrines an increase in the specific power of a SOFC cell with an SDC-bearing electrolyte due to an increase in the NRC, a decrease in ohmic and polarization resistance.

There are 10 Russian patents for utility models, of which only No. 213556 is valid – the model relates to medicine, namely surgery, to electrodes for monopolar coagulation with a diathermocoagulator; To achieve the result, the electrode material in the form of a cylindrical rod with a spherical thickening is made on the basis of an Nb-1 niobium alloy and praseodymium oxide, which increases the emissivity of the electrode.

There are no computer programs, databases and topologies of integrated circuits with praseodymium in the Russian Federation.

Praseodymium in modern Russia

In March 2023, the Mining Division of the State Corporation Rosatom officially announced the completion of the development of domestic technology for the extraction of rare earth metals, including praseodymium. The development of the technology was ordered by JSC Rusredmet (Leningrad Region), and specialists from JSC Atomredmetzoloto and JSC Solikamsk Magnesium Plant (JSC SMZ, an enterprise of the Mining Division of the State Corporation Rosatom) took part in the work.

The completed project provides that the production of cerium, lanthanum, neodymium, praseodymium and concentrate of the medium-heavy group of rare earth elements (samarium, gadolinium, europium) will be organized at OJSC SMZ. The raw material for the production of rare earth elements will be loparite concentrate, which is mined and enriched by another enterprise of the division – Lovozersky Mining and Processing Plant LLC (Lovozersky GOK LLC).

Currently, Russia imports the bulk of rare earth metals, with the share of imports reaching 90%. Since 2016, the country has zeroed out the mineral extraction tax on the extraction of these resources, and in 2022 they entered into scroll strategic mineral raw materials of Russia.

Several grants from government agencies for praseodymium have been noted. Thus, the development of a technology for producing high-purity (99.99%) compounds of individual rare earth elements (lanthanum, cerium, praseodymium, neodymium) for use in high-tech industries was carried out in 2017 by OJSC Gintsvetmet Institute. The conditions for obtaining individual light group REM compounds using new industrial resins and extractants have been studied. A reagent from the class of quaternary ammonium base was used as an extractant.

The study “Mid-IR fiber lasers based on chalcogenide glasses activated by rare earth ions” was carried out in 2022-2023. for 30 million rubles. Institute of General Physics named after. A.M. Prokhorov RAS with funds from the Russian Science Foundation. The scientific significance lies in the study of the behavior of rare earth activators (such as cerium, praseodymium, neodymium, terbium) in chalcogenide glasses from the point of view of spectral and luminescent properties and the convenience of optical pumping, as well as in the choice of fiber laser configuration.

Conclusion

The prospects for praseodymium in Russia are positive in the medium and long term from a production point of view. Rosatom structures will soon establish the production of rare earth metals in order to overcome import dependence. Fortunately, there are resources in the depths.

But the question of the development of breakthrough technologies related to the same praseodymium remains open. There are few active patents. But the same programs and databases do not exist at all.

There is no point in hoping for joint projects with GE, 3M or GM in the near future. Potentially, cooperation with Chinese organizations, such as Grirem, which occupies fifth place in the above-mentioned ranking, could help.

Useful from Online Patent: