Who discovered ruthenium. Ruthenium - chemical element: description, history and composition. Physiological action and biological role

Ruthenium is an element of the side subgroup of the eighth group of the fifth period of the periodic table of chemical elements of D.I. Mendeleev, atomic number 44. Denoted by the symbol Ru (lat. Ruthenium).

History of the discovery of ruthenium

The history of the discovery of this element began in Russia, when platinum deposits were discovered in the Urals in the 20s of the 19th century. The news of this discovery quickly spread around the world and caused a lot of anxiety and excitement in the international market. Among foreign speculators there were rumors about monstrous nuggets, about platinum sand, which platinum miners scooped up directly with shovels. Platinum deposits, indeed, turned out to be rich, and Count Kankrin, who was at that time the Minister of Finance of Russia, gave orders for the minting of platinum coins. Coins began to be minted in denominations of 3.6 and 12 rubles. 1,400,000 platinum coins were issued, using more than 20 tons of native platinum.

In the year of Kankrin’s order to mint coins, Yuryev University professor Ozanne, examining samples of Ural platinum, came to the conclusion that platinum was accompanied by three new metals. Ozanne named one of them a half-ran, the second a polynomial, and the third in honor of the Latin name. Russia - Ruthenia gave the name - ruthenium. Chemists greeted Ozanne's "discovery" with disbelief. The Swedish chemist Berzelius, whose authority at that time was truly global, especially protested. The dispute that arose between Ozanne and Berzelius was resolved by K. K. Klaus, a professor of chemistry at Kazan University. Having received at his disposal a small amount of remains from the minting of platinum coins, Klaus discovered a new metal in them, for which he retained the name ruthenium, proposed by Ozanne. On September 13, 1844, Klaus made a report at the Academy of Sciences about the new element and its properties. In 1845, Klaus's report entitled "Chemical Studies of the Remains of Ural Platinum Ore and Ruthenium Metal" was published as a separate book. “...The small amount of material studied - no more than six grams of completely pure metal - did not allow me to continue my research,” Klaus wrote in his book. However, the data obtained on the properties of the new metal made it possible for Klaus to firmly declare the discovery of a new chemical element.

Wanting to acquaint foreign scientists with the discovery of a new element, Klaus sent a sample of the metal to Berzelius. Berzelius' answer was strange to say the least. Having a new element in his hands with a detailed description of its properties, he did not agree with Klaus's opinion. Berzelius stated that the metal received from Klaus was “a sample of impure iridium,” a long-known element. Berzelius was later forced to admit his mistake.

Obtaining ruthenium

Separation of platinum metals and obtaining them in their pure form (refining) is a very difficult task, requiring a lot of labor, time, expensive reagents, and also high skill. Native platinum, platinum “scrap” and other material are first treated with “regia vodka” under low heat. In this case, platinum and palladium are completely transferred into solution in the form of H2 and H2, copper, iron and nickel - in the form of chlorides CuCl2, FeCl3, NiCl2. Rhodium and iridium are partially dissolved in the form of H3 and H2. The residue, insoluble in aqua regia, consists of a compound of osmium with iridium, as well as accompanying minerals (quartz SiO2, chromium iron ore FeCr2O4, magnetic iron ore Fe3O4, etc.). After filtering the solution, platinum is precipitated from it with ammonium chloride. However, in order for the precipitate of ammonium hexachloroplatinate not to contain iridium, which also forms sparingly soluble ammonium hexachloroiridite (IV) (NH4)2, it is necessary to reduce Ir (IV) to Ir (III). This is done by adding, for example, cane sugar C12H22O14 (I.I. Chernyaev’s method). Ammonium hexachloroiridite(III) is soluble in water and ammonium chloride does not precipitate. The precipitate of ammonium hexachloroplatinate is filtered off, washed, dried and calcined. The resulting platinum sponge is pressed and then fused in an oxygen-hydrogen flame or in an electric high-frequency furnace. Palladium, rhodium and iridium are extracted from the ammonium hexachloroplatinate filter; From the iridium alloy, iridium, osmium and ruthenium are distinguished. The chemical operations required for this are very complex. Currently, the main source of platinum metals is copper-nickel sulfide ores. As a result of their complex processing, the so-called “rough” metals are smelted - contaminated nickel and copper. During their electrolytic refining, noble metals accumulate in the form of anode sludge, which is sent for refining.

A significant source of ruthenium for its extraction is its isolation from fission fragments of nuclear materials (plutonium, uranium, thorium), where its content in spent fuel rods reaches 250 grams per ton of “burnt” nuclear fuel.

Physical properties of ruthenium

In terms of refractoriness (melt 2250 °C), ruthenium is inferior only to several elements - rhenium, osmium, tungsten.

The most valuable properties of Ruthenium are refractoriness, hardness, chemical resistance, and the ability to accelerate certain chemical reactions. The most typical compounds are those with valencies 3+, 4+ and 8+. Tends to form complex compounds. It is used as a catalyst, in alloys with platinum metals, as a material for sharp tips, for contacts, electrodes and in jewelry.

Chemical properties of ruthenium

Ruthenium and osmium are brittle and very hard. When exposed to oxygen and strong oxidizing agents, they form the oxides RuO4 and OsO4. These are fusible yellow crystals. The vapors of both compounds have a strong, unpleasant odor and are very poisonous. Both compounds easily give up oxygen, being reduced to RuO2 and OsO2 or to metals. With alkalis, RuO4 gives salts (ruthenates): 2Ru04 + 4KOH = 2K2RuO4 + 2H2O + O2

Applications of ruthenium

A small addition of ruthenium (0.1%) increases the corrosion resistance of titanium.
Alloyed with platinum, it is used to make extremely wear-resistant electrical contacts.
Catalyst for many chemical reactions. Ruthenium has a very important place as a catalyst in water purification systems of orbital stations.

Ruthenium's ability to catalytically bind atmospheric nitrogen at room temperature is also unique.

Ruthenium and its alloys are used as heat-resistant structural materials in aerospace engineering, and up to 1500 °C they are superior in strength to the best molybdenum and tungsten alloys (also having the advantage of high oxidation resistance).

In recent years, ruthenium oxide has been widely studied as a material for the production of supercapacitors for electricity, with a specific electrical capacity of over 700 Farads/gram.

Application of ruthenium for growing graphene

The synthesis is based on the fact that the solubility of carbon in ruthenium is strongly dependent on temperature. At 1150 °C, ruthenium is saturated with carbon, and when the temperature drops to 825 °C, carbon comes to the surface, resulting in the formation of graphene islands larger than 100 microns in size. The islands grow and unite, after which the growth of the second layer begins.

Ru
↓
Os

Story

origin of name

Receipt

Ruthenium is obtained as a “waste” from the refining of platinum and platinum metals.

A significant source of ruthenium for its extraction is its separation from fission fragments of nuclear materials (plutonium, uranium, thorium), where its content in spent fuel rods reaches 250 grams per ton of spent nuclear fuel.

A technology has also been developed for producing ruthenium from technetium-99 using neutron irradiation of molybdenum.

Production, reserves and price

Physical and chemical properties

Isotopic composition

Natural ruthenium consists of seven stable isotopes:

96 Ru (5.7% by weight), 98 Ru (2.2%), 99 Ru (12.8%), 100 Ru (12.7%), 101 Ru (13%), 102 Ru (31. 3%) and 104 Ru (18.3%).

Physical properties

By refractoriness ( T pl = 2334 °C) ruthenium is second only to several elements - rhenium, osmium, molybdenum, iridium, tungsten, tantalum and niobium.

Chemical properties

Ruthenium is a very inert metal.

Inorganic compounds

Organic chemistry of ruthenium

Ruthenium forms a number of organometallic compounds and is an active catalyst.

Application

A small addition of ruthenium (0.1%) increases the corrosion resistance of titanium.
Alloyed with platinum, it is used to make extremely wear-resistant electrical contacts.
Ruthenium dioxide and bismuth ruthenates are used in thick film resistors. These two electronics applications consume about 50% of the ruthenium produced.
Catalyst for many chemical reactions. Ruthenium has a very important place as a catalyst in water purification systems of orbital stations.
Ruthenium red en is used as a competitive antagonist for the study of ion channels (CatSper1, TASK, RyR1, RyR2, RyR3, TRPM6, TRPM8, TRPV1, TRPV2, TRPV3, TRPV4, TRPV5, TRPV6, TRPA1, mCa1, mCa2, CALHM1).

Ruthenium's ability to catalytically bind atmospheric nitrogen at room temperature is also unique. The discovery, made experimentally by researchers at the University of Minnesota in 2018, demonstrates that the chemical element ruthenium is the fourth chemical element that has unique magnetic properties at room temperature. Until recently, people knew only three stable magnetic elements, iron (Fe), cobalt (Co), nickel (Ni) and, partly, gadolinium (Gd), which loses its magnetic properties at temperatures above 8 degrees Celsius. The discovery of a new magnetic material could lead to the development of new types of sensors, storage devices, information processing devices and a host of other electronic and electromechanical devices. In addition to traditional technologies that use the magnetic properties of materials, the emergence of a new magnetic material can play an important role in the further development of a number of new areas, such as spintronics. This will be facilitated by the fact that the technologies for growing thin films and creating nanostructures have already reached a level that allows the production of materials with unique properties that these same materials of natural origin do not possess.

Ruthenium and its alloys are used as heat-resistant structural materials in aerospace engineering, and up to 1500°C are superior in strength to the best molybdenum and tungsten alloys (also having the advantage of high oxidation resistance).

Physiological action and biological role

Ruthenium appears to be a trace element. It is the only platinum metal that is found in living organisms (according to some sources, platinum is also present). Concentrated mainly in muscle tissue.

Ruthenia means "Russia" in Latin. Like Russia, ruthenium is beautiful, mysterious and extremely inconvenient for humans. Firstly, obtaining pure ruthenium is a problem, has not yet been resolved. Secondly, ruthenium is so fragile that it is not possible to use it in its pure form. Third, ruthenium, found in the form of various chemical compounds, is often dangerous. Including explosive ones!

Why not Russia?

History of metal

Karl-Ernst Klaus, a Baltic German, was born and raised in Estonia. As a child, he was torn between the desire to become a botanist and the idea of making a living as an apothecary. However, fate told him to forget about nonsense, realize himself as a Russian chemist and go to serve at Kazan University.
Karl Karlovich resisted as best he could. He married a German woman, did not give up botany (one of the cabbage genera is named after him), and treated chemistry not only with disdain, but... not seriously. He touched acids with his hands, tasted solutions, smelled poisonous gases in order to remember their smell, and often expressed thoughts unbecoming of a respectable scientist. In general, he showed all the traits of the Russian character - and not in vain!

Most of the statements made by Professor K.K. Klaus's ideas, too bold for their time, turned out to be correct. Implementing one of them, in 1844, Klaus received six grams of a metal previously unknown to science and subsequently named ruthenium.

The luminaries of the world community noted the closeness of the new metal, partly to iron, partly to osmium. A strong opinion arose - and has not disappeared since then - that Of all the so-called “noble” metals, ruthenium is the most base...

Properties of ruthenium

For one hundred and fifty years now, ruthenium has been at the complete disposal of researchers, but there is still no comprehensive understanding of its capabilities. Experimenters were faced with a paradoxical phenomenon: the physical properties of this platinum substance change depending on the method of obtaining the metal.

The presence of a difference in properties, scientists understand, only indicates that the samples are contaminated. Awareness of the problem is partly puzzling, because there is no effective way to purify ruthenium from impurities; and partly it is encouraging, since the theoretical characteristics of the substance are very enviable.

One way or another, today it is not possible to rid ruthenium of the inherent fragility of its castings. Attempts at mechanical processing (forging, pressing, cutting) end in the destruction of the ruthenium workpiece.

Meanwhile, production workers are very interested in “conquering” metal: the gas absorption capabilities of ruthenium are unsurpassed. If palladium is able to absorb hydrogen 940 times its volume, then for ruthenium this figure is almost twice as high! Moreover, the absorption capacity of ruthenium concerns not only hydrogen, but also nitrogen, and - to a lesser extent - other non-metals.

Ruthenium tetroxide RuO4 (as well as finely divided rhodium) is so chemically active that it is even explosive. True, both rhodium and ruthenium explosives are quite expensive...

Price and prevalence

According to geologists, there is no more than five thousand tons of ruthenium in the earth's crust. Such a small quantity, scattered nature and difficulty of extraction determine the initially high cost of the metal.

However, limited demand makes adjustments to the price list of precious metals. Ruthenium is the most inexpensive of. Its market value at the beginning of 2016 is only 2.7 times higher than the price of ruthenium, which is almost 30 times more expensive - despite the fact that the annual production of ruthenium rarely exceeds 20 tons, and 2,500 tons of gold enter the world market per year.

No fairness in pricing! Just as it doesn’t exist in the country of Ruthenia...

Where does ruthenium go?

Unlike most precious metals, ruthenium is not used in the jewelry industry, absolutely. The point here is not only the lack of expressiveness of its natural appearance and the inconvenience of its physical properties. The chemical activity of ruthenium compounds is so great Doctors are confident that the introduction of metal into human use will inevitably lead to an increase in morbidity.
The lion's share of mined ruthenium goes to the electronics industry. About a third of the production volume is purchased by enterprises of the electrochemical cycle. The remaining third is consumed by conventional chemical production. Very few ruthenium compounds are required by medicine for the manufacture of research and therapeutic drugs.

Water purification devices on spacecraft operate on ruthenium catalysts - they are the most effective. In non-ferrous metallurgy, ruthenium is a valuable alloying additive. In concentrations of tenths and hundredths of a percent, the noble metal significantly increases the strength properties of products. Turbine blades of jet engines, high-temperature parts of rockets, and fuel equipment for aircraft contain ruthenium.

Some technologies for producing graphene are based on the use of ruthenium's ability to absorb non-metals. The ruthenium substrate turns out to be a reliable basis for growing modified carbon.

A powdered mixture of ruthenium dioxide and ruthenium tetroxide allows forensic scientists to identify faint fingerprints. No other compounds “bite” into fat molecules with such force!

The use of ruthenium paint as...a solar battery seems very promising. In the future, a person will be able to utilize solar energy using a converter worn in the form of a can of paint and two wires - and such a system promises to cost mere pennies.

Problematic ruthenium

Nuclear scientists, and along with them environmentalists, faced the ruthenium problem. For them, radioactive ruthenium, which appears in reactors during the decay of uranium and plutonium, is a serious and intractable problem.

Up to a third of the slag mass in the reactor consists of dangerous radioruthenium. Extremely sticky metal is extremely difficult to remove. But when preserving nuclear waste, ruthenium is the first to find a way out of storage! Migration of active ruthenium occurs in all possible ways.

It is not always possible to put a reliable barrier in the way of an element that is too “movable,” or to decontaminate the metal. Leguminous plants, a favorite food of humans and animals, concentrate soil ruthenium in their roots.

Ruthenium is the lightest and least “noble” of all the platinum group metals. It is perhaps the most “multivalent” element (nine valence states are known). Despite more than half a century of study history, it still poses many questions and problems for modern chemists. So what is ruthenium as a chemical element? To begin with, a short excursion into history.

Mysterious and rich

The name and history of the discovery of ruthenium are inextricably linked with Russia. At the very beginning of the 19th century, the world community was excited and concerned by the news that the richest deposits of platinum had been discovered in the Russian Empire. There were rumors that in the Urals the extraction of this precious metal could be carried out with an ordinary shovel. The fact of the discovery of rich deposits was soon confirmed by the fact that the Minister of Finance of Russia E.F. Kankrin sent the highest decree to the St. Petersburg Mint on the minting of coins from platinum. In subsequent years, about one and a half million coins (3.6 and 12 rubles) were put into circulation, the production of which required 20 tons of precious metal.

"Discovery" by Ozanne

Professor of the Dorpat-Yuryev (now Tartu) University Gottfried Ozanne began studying the composition of the Ural precious ore. He came to the conclusion that platinum was accompanied by three unknown metals - poluran, polynomial and ruthenium - the names of which were given by Ozanne himself. By the way, he named the third one in honor of Russia (from the Latin Ruthenia).

Ozanne's colleagues throughout Europe, led by the most authoritative Swedish chemist Jens Berzelius, were very critical of the professor's message. In an attempt to justify himself, the scientist repeated a series of his experiments, but failed to achieve the same results.

Two decades later, chemistry professor Karl Karlovich Clauss (Kazan University) became interested in Ozanne’s work. He obtained permission from the Secretary of the Treasury to obtain several pounds of coin production residues from the Mint laboratory for re-examination.

Russian academician A.E. Arbuzov noted in his writings that in order to discover a new element in those days, a chemist needed extreme hard work and perseverance, observation and insight, and most importantly, a subtle experimental sense. All of the above qualities were inherent to the highest degree in the young Karl Clauss.

The scientist’s research also had practical significance - additional extraction of pure platinum from ore residues. Having developed his own experimental plan, Clauss fused the ore material with saltpeter and extracted the soluble elements: osmium, iridium, palladium. The insoluble part was exposed to a mixture of concentrated acids ("aqua regia") and distilled. In the precipitate of iron hydroxide, he discovered the presence of an unknown metal and isolated it first in the form of sulfide, and then in pure form (about 6 grams). The professor retained the name proposed by Ozanne for the element - ruthenium.

Open and prove

But as it turned out, the story of the discovery of the chemical element ruthenium was just beginning. After the results of the study were published in 1844, a hail of criticism fell on Clauss. The findings of the unknown Kazan scientist were met with skepticism by the world's leading chemists. Even sending a sample of the new element to Berzelius did not save the situation. According to the Swedish master, Clauss's ruthenium was only a "sample of impure iridium."

Only the outstanding qualities of Karl Karlovich as an analytical and experimental chemist and a series of additional studies allowed the scientist to prove that he was right. In 1846, the discovery received official recognition and confirmation. For his work, Klauss was awarded the Demidov Prize of the Russian Academy of Sciences in the amount of 10 thousand rubles. Thanks to the talent and perseverance of the Kazan professor, ruthenium was added to the ranks of platinoids - the first element discovered in Russia (and today, unfortunately for the domestic chemical school, the only one).

Further research

Areas of use

Although all the properties of a noble metal are fully present in ruthenium, the element is not widely used in the jewelry industry. It is used only to strengthen alloys and make expensive jewelry more durable.

According to the amount of ruthenium consumed, industrial sectors are arranged in the following order:

Electronic.
Electrochemical.
Chemical.

The catalytic properties of the element are in great demand. It is used in the synthesis of hydrocyanic and nitric acids, in the production of saturated hydrocarbons, glycerol and the polymerization of ethylene. In the metallurgical industry, ruthenium additives are used to increase anti-corrosion properties, impart strength, chemical and mechanical resistance to alloys. Radioactive isotopes of ruthenium often help scientists conduct scientific research.

Many compounds of the element have also found use as good oxidizing agents and dyes. In particular, chlorides are used to enhance luminescence.

Biological significance

Ruthenium has the ability to accumulate in living tissue cells, mainly muscle cells (the only one of the platinum group metals). May provoke the development of allergic reactions and have a negative effect on the mucous membrane of the eyes and upper respiratory tract.

In medicine, the noble metal is used as a means to recognize affected tissues. Medicines based on it are used to treat tuberculosis and various infections that affect human skin. For this reason, the use of ruthenium’s ability to form strong nitroso complexes in the fight against diseases associated with excessive concentrations of nitrates in the human body (hypertension, arthritis, septic shock and epilepsy) looks very promising.

Who is guilty?

More recently, scientists in Western Europe seriously worried the public with the message that the content of the radioactive isotope of ruthenium Ru 106 is growing over the continent. Experts completely rule out its self-formation in the atmosphere. As well as an emergency release from a nuclear power plant, since then cesium and iodine radionuclides would necessarily be present in the air, which is not confirmed by experimental data. The impact of this isotope on the human body, like any radioactive element, leads to irradiation of tissues and organs and the development of cancer. Possible sources of pollution, according to Western media, are located in Russia, Ukraine or Kazakhstan.

In response, a representative of the Rosatom Communications Department stated that all enterprises of the state corporation were and are working as usual. The International Atomic Energy Agency (IAEA), in its conclusion, based on its own monitoring data, called all accusations against the Russian Federation groundless.

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Sergeeva Ekaterina Yurievna

State Autonomous Educational Institution "Chistopol Polytechnic College"

Head Ionycheva A.L.

ANNOTATION

In this work, I was interested in the history of the discovery, properties and possible areas of application of the chemical element Ruthenium, which was discovered by Karl Karlovich Klaus in the chemical laboratory of Kazan University and can rightfully be called the Kazan chemical element. 2011 was declared the Year of Chemistry by UNESCO, students of Kazan and the Republic of Tatarstan should remember this clearly extraordinary event in the more than 1000-year history of the city of Kazan And the only person in Russia, K.K. Klaus, who discovered a natural chemical element, especially since he is rightfully considered one of the founders of the Kazan chemical school.

This topic seemed interesting and relevant to us also because

Ruthenium is one of the representatives of the platinum metals, but was the most recently discovered. The discovery of Ruthenium presented great difficulties.

In order to discover a new element of the platinum group - ruthenium - in the time of Klaus, one had to have extreme observation, insight, hard work, perseverance and subtle experimental art. Klaus, one of the first brilliant representatives of chemical science at the then young Kazan University, possessed all these qualities to a high degree.

While studying the problem, we used materials from the Internet resource: the World of Chemistry website, Wiktionary, Popular Library of Chemical Elements, Nauka Publishing House, 2011.

During the week of natural sciences, we held (among other events) a scientific and practical conference: “Great chemists and their discoveries”, at which research works and a number of presentations were presented, which became a good help in the work of teachers and the interest of students in studying chemistry and other natural disciplines.

Kazan chemical element (Ruthenium)

“To discover a new element of the platinum group, ruthenium, in the time of Klaus, one had to have extreme observation, insight, hard work, perseverance and subtle experimental art. Klaus, one of the first brilliant representatives of chemical science at the then young Kazan University, possessed all these qualities to a high degree.”

Academician A.E. Arbuzov

History of the discovery of ruthenium

Ruthenium was the first chemical element discovered by the Russian chemist Karl Karlovich Klaus. Ruthenium is a representative of the platinum metals and was the last to be discovered.

The research was carried out by A. Snyadetsky, a Pole by nationality, and the Russian scientist K.K. Klaus. E.F. provided great assistance to the scientist. Kankrin, who at that time held the post of Minister of Finance

K.K. Klaus

It was he who provided Klaus with the remains of raw platinum, from which the scientist isolated platinum, as well as other metals: rhodium, palladium, iridium and osmium. In addition to these metals, he also isolated a mixture of others, which, according to Klaus, should contain a new, still unknown substance. The chemist repeated the experiments of G.V. Ozanne, and then, having developed his own experimental plan, obtained a new chemical element, ruthenium. And again he sent a letter to I. Bercellius, but he, as the first time, did not agree with Klaus’s arguments. But the Russian chemist did not heed Bercellius’s arguments and proved that he had discovered a new chemical element of the platinum group. And in 1845, Bercellius recognized the discovery of ruthenium.

A chemical element is named after Russia (the Latin name for Russia is Ruthenia)

At the request of the Ministry of Finance, Kazan University professor Karl Karlovich Klaus in 1841 began searching for a way to process the remains of platinum ores accumulated at the St. Petersburg Mint in order to more fully extract platinum. A year earlier, through the efforts of Rector Lobachevsky, a separate two-story building with a huge basement, equipped with the most modern equipment, was erected for the chemical laboratory.

Klaus established the composition of platinum ore residues and developed methods for separating and obtaining pure platinum metals. Klaus had to overcome exceptional experimental difficulties, given the level of knowledge at that time. In addition, the work was hazardous to health, since extremely toxic substances were formed during the processing of ores.

Among the isolated components, Klaus discovered a previously unknown metal. He studied the properties of both the metal itself and its compounds, determined its atomic weight with special care, and developed a method for its isolation and purification. In 1844, Klaus published his results, naming the new chemical element ruthenium, after Russia. The world scientific community initially accepted this discovery with doubt, since many elements were “discovered” by mistake.

It was not until 1846, when Klaus published a new paper on further study of ruthenium, that his discovery was universally accepted. Soon the Kazan professor was awarded the Demidov Prize by the Russian Academy of Sciences for research in the field of platinum metals. Its value of 10,000 rubles was then much greater than the current Nobel Prize.

Chemical laboratory of Kazan University, where Klaus worked in 1842. A hundred years later, the future Kurchatov Institute began its work in this room.

Obtaining ruthenium

Separation of platinum metals and obtaining them in their pure form (refining) is a very difficult task, requiring a lot of labor, time, expensive reagents, as well as high skill. Currently, the main source of platinum metals is sulfide copper-nickel ores. As a result of their complex processing, the so-called “rough” metals are smelted - contaminated nickel and copper. During their electrolytic refining, noble metals accumulate in the form of anode sludge, which is sent for refining.

A significant source of ruthenium for its extraction is its separation from fission fragments of nuclear materials (plutonium, uranium, thorium), where its content reaches 250 grams per ton of “burnt” nuclear fuel.

Physical properties of ruthenium.

In terms of refractoriness (melt 2250 °C), ruthenium is inferior only to several elements - rhenium, osmium, tungsten.

Chemical properties of ruthenium.

Task No. 1: How to get rid of ruthenium?

Ruthenium has many valuable and interesting properties. In many mechanical, electrical and chemical characteristics it can compete with many metals and even with platinum and gold. However, unlike these metals, ruthenium is very fragile, and therefore it has not yet been possible to make any products from it. Task No. 1 has been assigned to nuclear technology scientists.

Radioactive isotopes of ruthenium do not exist in nature, but they are formed as a result of the fission of uranium and plutonium nuclei in reactors of nuclear power plants, submarines, ships, and during explosions of atomic bombs. From a theoretical point of view, this fact is certainly interesting. It even has a special “zest”: the dream of alchemists has come true - a base metal has turned into a noble one. Indeed, these days, plutonium production plants throw out tens of kilograms of the noble metal ruthenium. But the practical harm caused by this process to nuclear technology would not be worth it even if it were possible to put all the ruthenium produced in nuclear reactors to good use.

Why is ruthenium so harmful?

One of the main advantages of nuclear fuel is its reproducibility. As is known, when uranium blocks are “burned” in nuclear reactors, a new nuclear fuel is formed - plutonium. At the same time, “ash” is formed - fragments of the fission of uranium nuclei, including ruthenium isotopes. Ash, of course, has to be removed.

Ruthenium begins to gradually migrate into the ground, creating the danger of radioactive contamination at large distances from the reservoir. The same thing happens when fragments are buried in mines at great depths. Radioactive ruthenium, which has (in the form of water-soluble nitroso compounds) extreme mobility, or, more correctly, migration ability, can travel very far with groundwater.

Physicists, chemists, technologists, and especially radiochemists in many countries pay a lot of attention to the fight against radioactive ruthenium. At the I and II International Conferences on the Peaceful Uses of Atomic Energy in Geneva, several reports were devoted to this problem. However, there is still no reason to consider the fight against ruthenium completed successfully, and, apparently, chemists will have to work a lot more in order for this problem to be transferred to the category of finally solved.

Task No. 2: further study of the chemistry of ruthenium and its compounds.

The extraordinary relevance of task No. 1 forces researchers to penetrate ever deeper into the chemistry of ruthenium and its compounds.

Ruthenium is a rare and very trace element. It is the only mineral known to form under natural conditions. This is laurite RuS 2 – a very hard, heavy, black substance that is extremely rare in nature. In some other natural compounds, ruthenium is just an isomorphic impurity, the amount of which, as a rule, does not exceed tenths of a percent. Small impurities of ruthenium compounds were discovered in copper-nickel ores of the Canadian Sedbury deposit, and then in other mines.

One of the most remarkable chemical properties of ruthenium is its many valence states. The ease of transition of ruthenium from one valence state to another and the abundance of these states lead to the extreme complexity and originality of ruthenium chemistry, which is still replete with many blank spots.

Soviet scientist Sergei Mikhailovich Starostin devoted his entire life to studying the chemistry of ruthenium and its compounds. It was he who established that the enormous difficulties that arise when separating ruthenium from plutonium and uranium are associated with the formation and properties of ruthenium nitroso complexes.

Some scientists suggest that it will be possible to isolate inorganic polymers based on ruthenium nitroso complexes.

Several decades ago, ruthenium complexes provided important service to the theory of chemistry, becoming an excellent model with which Werner created his famous coordination theory. Perhaps polymer compounds of ruthenium will serve as a model for creating the theory of inorganic polymers.

Challenge #3: Use of Ruthenium

Where is ruthenium used and what are the prospects for its use?

Ruthenium, like platinum and palladium, has catalytic properties, but often differs from them in greater selectivity and selectivity. Heterogeneous catalysis uses the metal ruthenium and its alloys. The most effective catalysts are obtained by depositing ruthenium on various supports with highly developed surfaces. In many cases it is used together with platinum in order to increase its catalytic activity. An alloy of rhodium, ruthenium and platinum accelerates the oxidation of ammonia in the production of nitric acid. Ruthenium is used for the synthesis of hydrocyanic acid from ammonia and methane, to obtain saturated hydrocarbons from hydrogen and carbon monoxide. A method for the polymerization of ethylene on a ruthenium catalyst has been patented abroad.

Ruthenium catalysts have become important for the reaction of producing glycerol and other polyhydric alcohols from cellulose by hydrogenation.

Organometallic compounds of ruthenium are used in homogeneous catalysis for various hydrogenation reactions, and in terms of selectivity and catalytic activity they are not inferior to recognized rhodium-based catalysts.

The main advantage of the ruthenium catalyst is its high selectivity. It is this that allows chemists to use ruthenium to synthesize a wide variety of organic and inorganic products. Ruthenium catalyst is beginning to seriously compete with platinum, iridium and rhodium.

Element No. 44 is somewhat less capable in metallurgy, but it is also used in this industry. Small additions of ruthenium usually increase the corrosion resistance, strength and hardness of the alloy. Most often it is introduced into metals from which contacts for electrical engineering and radio equipment are made. An alloy of ruthenium and platinum has found application in the fuel cells of some American artificial Earth satellites. Alloys of ruthenium with lanthanum, cerium, scandium, and yttrium have superconductivity. Thermocouples made from an alloy of iridium and ruthenium can measure the highest temperatures.

Much can be expected from the use of ruthenium coatings applied in the form of a thin layer (film) on various materials and products. Such a film significantly changes the properties and quality of products, increases their chemical and mechanical resistance, makes them corrosion-resistant, dramatically improves electrical properties, etc. Thin coatings made of noble metals, including ruthenium, have become increasingly important in recent years in various fields of electronics, radio and electrical engineering, the chemical industry, and also in jewelry.

An interesting property of ruthenium metal - sorbing and passing hydrogen - can be successfully used to extract hydrogen from a mixture of gases and obtain ultra-pure hydrogen.

Many ruthenium compounds have beneficial properties. Some of them are used as additives in glass and enamels as permanent dyes; ruthenium chlorides, for example, increase the luminescence of luminol, ruthenium polyamines have fluorescent properties, Na2 2H2O salt is a piezoelectric, RuO4 is a strong oxidizing agent. Many ruthenium compounds have biological activity.

"Eternal" feather

Fountain pen nibs constantly rub against the paper and therefore wear off. To make the pen truly “eternal”, the tip is soldered. Some alloys for soldering “eternal” feathers include ruthenium. In addition to it, these alloys contain tungsten, cobalt, and boron.

Ruthenium is also used in the manufacture of alloys for compass needle supports. These alloys must be hard, strong and elastic. Among natural minerals, the very rare osmic iridium has such properties. Artificial materials for compass needles, along with osmium and iridium, and sometimes other metals, include element No. 44 - ruthenium.

There is contact!

In electrical engineering, copper has long been used for contacts. It is an ideal material for transmitting strong currents. So what if after a certain time the contacts become coated with copper oxide? You can wipe them with sandpaper and they will shine again, like new. It's a different matter in low-current technology. Here, any oxide film on the contact can disrupt the operation of the entire system. Therefore, contacts for low currents are made of palladium or a silver-palladium alloy. But these materials do not have sufficient mechanical strength. The addition of small amounts of ruthenium (1...5%) to the alloys gives the contacts hardness and strength. The same applies to sliding contacts, which must resist abrasion well.

Ruthenium red.

This is the name of an inorganic dye, which is a complex ammonium chloride of ruthenium. Ruthenium red is used in studies in anatomy and histology (the science of living tissues). A solution of this dye, when diluted 1:5000, colors pectin substances and some fabrics in pink and red tones. Thanks to this, the researcher is able to distinguish these substances from others and better analyze the section examined under the microscope.

Application of Ruthenium for growing graphene.

Researchers from Brookhaven National Laboratory (USA) have shown that during the epitaxial growth of graphene, macroscopic graphene regions are formed on the Ru(0001) surface. In this case, growth occurs layer by layer, and although the first layer is strongly connected to the substrate, the second practically does not interact with it and retains all the unique properties of graphene.
The synthesis is based on the fact that the solubility of carbon in ruthenium is strongly dependent on temperature. At 1150 °C, ruthenium is saturated with carbon, and when the temperature drops to 825 °C, carbon comes to the surface, resulting in the formation of graphene islands larger than 100 microns in size. The islands grow and unite, after which the growth of the second layer begins.