Beryllium is a light gray, lightweight, fairly hard, brittle metal. In air it becomes covered with an oxide film.
Receipt:
In the form of a simple substance in the 19th century, beryllium was obtained by the action potassium to anhydrous beryllium chloride: BeCl2+2K=Be+2KCl.B e C l 2 + 2 K ⟶ B e + 2 K C l (\displaystyle (\mathsf (BeCl_(2)+2K\longrightarrow Be+2KCl)))
Currently, beryllium is produced reducing beryllium fluoride with magnesium: BeF2+Mg=Be+MgF2,
or electrolysis melt of a mixture of beryllium and sodium chlorides.
Chemical properties:
Beryllium has only one oxidation state, +2. In many chemical properties, beryllium is more similar to aluminum than to magnesium, which is located directly below it in the periodic table (manifestation of “ diagonal similarity "). Beryllium metal is relatively little reactive at room temperature.
Passivates in cold water, concentrated sulfur and nitric acids. A reducing agent, it reacts with boiling water, dilute acids, concentrated alkalis, non-metals, ammonia, metal oxides, and burns in oxygen and air when heated. Beryllium forms intermetallic compounds with metals.
2Be + O 2 (900°C) = 2BeO
Beryllium does not react with hydrogen even when heated to 1000°C, but it easily combines with halogens, sulfur and carbon.
Be + Hal 2 (load) = 2BeHal 2 (7Be+2F→Be 7 F 2 ; 2Be+I 2 →2BeI)
3Be + C 2 H 2 = BeC 2 + H 2
Be + MgO = BeO + Mg
Interaction with sulfur: 2Be+S→Be 2 S
Interaction with nitrogen (N): 2Be+N 2 →2BeN
Beryllium dissolves well in all mineral acids, except, oddly enough, nitric acid. From it, as from oxygen, beryllium is protected by an oxide film.
Be + 2HCl(diluted) = BeCl 2 + H 2
3Be + 8HNO3(dil) = 3 Be(NO3)2 + 2 NO + 4 H2O
Beryllium reacts with alkalis to form beryllate salts, similar to aluminates. Many of them have a sweetish taste, but you cannot taste them on your tongue - almost all beryllates are poisonous.
Be + 2NaOH(conc.) + H 2 O = Na 2 BeO 2 + H 2
Be + 2NaOH(melt) = Na 2 + H 2
Interaction with water:
2Be+3H 2 O→2H 2 + BeO + Be(OH) 2
2Be + 3H 2 O(boiling) = BeO↓ + Be(OH) 2 ↓ + 2H 2
Beryllium is prone to the formation of complex compounds when interacting with aqueous solutions of alkalis.
Interaction with nitric acid:
Interaction with alkali solutions:
Be + 2KOH + 2H 2 O = K 2 + H 2
Production and Application:
In Russia, it is planned to build a new beryllium production plant by 2019. The remaining countries accounted for less than 1% of world production. In total, the world produces 300 tons of beryllium per year (2016).
Alloying of alloys
Beryllium is mainly used as an alloying additive to various alloys. The addition of beryllium significantly increases the hardness and strength of alloys, and the corrosion resistance of surfaces made from these alloys. X-ray technology Beryllium weakly absorbs x-ray radiation, that’s why windows are made from it x-ray tubesNuclear power
IN nuclear reactors made from beryllium neutron reflectors, it is used as neutron moderator. Laser materials In laser technology, beryllium aluminate is used for the manufacture of solid-state emitters (rods, plates). Aerospace engineering
In the production of heat shields and guidance systems, almost no other structural material can compete with beryllium. Propellant It is worth noting the high toxicity and high cost of beryllium metal, and therefore significant efforts have been made to identify beryllium-containing fuels that have significantly lower overall toxicity and cost. One such beryllium compound is beryllium hydride.Fireproof materials It serves as a highly thermally conductive, high temperature insulator and refractory material for laboratory crucibles and other special applications. Acoustics
Due to its lightness and high hardness, beryllium is successfully used as a material for electrodynamic loudspeakers. Biological role and physiological effect:
In living organisms, beryllium does not have any significant biological function. However, beryllium can replace magnesium in some enzymes, which leads to disruption of their work. The daily intake of beryllium in the human body through food is about 0.01 mg.
(just in case)
Beryllium(II) compounds. In sour aqueous solutions Be 2+ ions are in the form of strong aqua complexes [Be(H 2 O) 4 ] 2+ ; in strongly alkaline solutions - in the form of [Be(OH) 4 ] 2– ions.
BeO Oxide– ampholyte, upon fusion interacts with both basic and acidic oxides:
BeO + SiO 2 = BeSiO 3; BeO + Na 2 O = Na 2 BeO 2
When heated, BeO reacts with alkalis and acids:
BeO + 2HCl(conc.) = BeCl 2
BeO + 2NaOH + H 2 O = Na 2 [Be(OH) 4 ]
BeO is used as a chemically resistant and refractory material for the manufacture of crucibles and special ceramics, and in nuclear energy as a neutron moderator and reflector.
Be(OH) hydroxide 2 – a polymer compound, and therefore does not dissolve in water, ampholyte.
Be(OH) 2 + 2NaOH(conc.) = Na 2 [Be(OH) 4 ]
BeO + 2HCl + 3H 2 O = [Be(H 2 O) 4 ]Cl 2
Amphoteric VeNa1 2 is most clearly manifested in fluoride. Thus, when BeF 2 is heated with basic fluorides, fluoroberyllates are formed (other halogenoberyllates are not typical): 2KF + BeF 2 = K 2
When BeF 2 interacts with acid fluorides, beryllium salts are formed:
BeF 2 + SiF 4 = Be
VeH hydride 2 – strong reducing agent; when it decomposes with water, hydrogen is released: BeH 2 + 2H 2 O = Be(OH) 2 ↓ + H 2
Most beryllium salts are soluble in water; BeCO 3, Be 3 (PO 4) 2 and some others are insoluble. Beryllium is characterized by double salts - beryllates with complex ligands, for example:
Na 2 SO 4 + BeSO 4 = Na 2
(NH 4) 2 CO 3 + BeCO 3 = (NH 4) 2
First of all, there are several (there may be many more!) answers to the question: “What can beryllium give us?”... An airplane whose weight is half as much as usual; ...rocket fuel with the highest specific impulse; ...springs that can withstand up to 20 billion (!) load cycles - springs that do not know fatigue, practically eternal.
And at the beginning of our century, reference books and encyclopedias said about beryllium: “It has no practical use.” Opened at the end of the 18th century. beryllium 100 s extra years remained an “unemployed” element, although chemists were already aware of its unique and very useful properties. In order for these properties to cease to be a “thing in itself”, a certain level of development of science and technology was required. In the 30s, Academician A.E. Fersman called beryllium the metal of the future. Now we can and should talk about beryllium as a real metal.
Misunderstanding with the periodic table
The story of element No. 4 began with the fact that it could not be opened for a long time. Many chemists of the 18th century. analyzed beryl (the main mineral of beryllium), but none of them could find a new element in this mineral.
Even a modern chemist, armed with photometric, polarographic, radiochemical, spectral, radioactivation and fluorimetric methods of analysis, finds it difficult to identify this element, as if hiding behind aluminum and its compounds - their characteristics are so similar. The first researchers of beryllium, of course, had a much more difficult time.
But in 1798 French chemist Louis Nicolas Vauquelin studying comparative analysis beryl and emerald, discovered an unknown oxide in them - “earth”. It was very similar to aluminum oxide (alumina), but Vauquelin noticed differences. The oxide dissolved in ammonium carbonate (but aluminum oxide does not dissolve); the sulfate salt of the new element did not form alum with potassium sulfate (but aluminum sulfate does form such alum). It was this difference in properties that Vauquelin took advantage of to separate aluminum oxides and an unknown element. The editors of the magazine “Annales de chimie”, which published Vauquelin’s work, proposed the name “glycine” (from the Greek γλυμυς - sweet) for the “earth” he discovered because of the sweet taste of its salts. However famous chemists M. Klaproth and A. Ekeberg considered this name to be unfortunate, since yttrium salts also have a sweetish taste. In their works, the “earth” discovered by Vauquelin is called beryl. However, in the scientific literature of the 19th century, right up to the 60s, element No. 4 was often called “glycium”, “wisterium” or “glucinium”. Nowadays this name is preserved only in France.
It is interesting to note that the proposal to call element No. 4 beryllium back in 1814 was made by Kharkov professor F.I. Giese.
The oxide was obtained, but still for a long time No one has been able to isolate beryllium in its pure form. Only 30 years later, F. Wöhler and A. Bussy obtained some powdered metal by the action of potassium metal on beryllium chloride, but this metal contained many impurities. Almost another 70 years passed before P. Lebeau was able to obtain (in 1898) pure beryllium by electrolysis of beryllium sodium fluoride.
The similarity of beryllium to aluminum brought a lot of trouble to the author periodic law DI. Mendeleev. It is because of this similarity that in the middle of the last century beryllium was considered a trivalent element with an atomic weight of 13.8. But, being placed in the table between carbon and nitrogen, as required by its atomic weight, beryllium introduced complete confusion into the natural change in the properties of the elements. This was a serious threat to periodic law. However, Mendeleev was confident in the correctness of the pattern he discovered and argued that the atomic weight of beryllium was determined incorrectly, that beryllium should not be a trivalent, but a divalent element “with magnesian properties.” Based on this, Mendeleev placed beryllium in the second group periodic table along with divalent alkaline earth metals, correcting its atomic weight to 9.
Mendeleev found the first confirmation of his views in one of the little-known works of the Russian chemist I.V. Avdeev, who believed that beryllium oxide is chemically similar to magnesium oxide. And in the late 70s of the last century, Swedish chemists Lare Frederik Nilsson and Otto Peterson (who were once the most ardent supporters of the opinion on trivalent beryllium), having re-determined the atomic weight of beryllium, found it equal to 9.1.
So beryllium former first a stumbling block on the path of the periodic law, only confirmed its universality. Thanks to the periodic law, the concept of the physical and chemical essence of beryllium has become clearer. Figuratively speaking, beryllium finally received its “passport”.
Now people of many professions are interested in beryllium. Each of them has its own approach to element No. 4, its own “beryllium” problems.
Beryllium from a geologist's point of view
A typically rare item. On average, there is only 4.2 g of beryllium per ton of earthly matter. This, of course, is very little, but not so little, if we remember, for example, that such a well-known element as lead is half as much on Earth as beryllium. Beryllium is usually found as a minor impurity in various minerals in the earth's crust. And only an insignificant part of the earth's beryllium is concentrated in its own beryllium minerals. More than 30 of them are known, but only six of them are considered more or less common (beryl, chrysoberyl, bertrandite, phenacite, helvin, danalite). And serious industrial value I have purchased only one beryl so far, known to man since ancient times.
Beryls are found in granitic pegmatites, found in almost all countries of the globe. These are beautiful greenish crystals, sometimes reaching very large sizes; Giant beryls weighing up to a ton and up to 9 m long are known.
Unfortunately, pegmatite deposits are very small, and it is not possible to mine beryl there on a large industrial scale. However, there are other sources of beryllium in which its concentration is much higher. These are so-called pneumatic-hydrothermal deposits (i.e. deposits formed as a result of the interaction of high-temperature vapors and solutions with certain types of rocks).
Natural beryllium consists of a single stable isotope, 9Be. It is interesting that beryllium is the only element of the periodic table that has only one even number stable isotope. Several other unstable, radioactive isotopes of beryllium are known. (Two of them – 10 Be and 7 Be – will be discussed below.)
Beryllium from a metallurgist's point of view
The properties of beryllium are most often called “amazing”, “wonderful”, etc. This is partly true, and the main “surprise” lies in the combination of opposite, sometimes seemingly mutually exclusive properties. Beryllium is both lightweight, durable, and heat resistant. This silver-gray metal is one and a half times lighter than aluminum and at the same time stronger than special steels. It is especially important that beryllium and many of its alloys do not lose useful properties at temperatures of 700...800°C and can work in such conditions.
Pure beryllium is very hard and can be used to cut glass. Unfortunately, hardness comes with fragility.
Beryllium is very resistant to corrosion. Like aluminum, when exposed to air, it is coated with a thin oxide film, which protects the metal from the action of oxygen even at high temperatures. Only above the threshold of 800°C does the oxidation of beryllium in the mass occur, and at a temperature of 1200°C metallic beryllium burns, turning into white BeO powder.
Beryllium easily forms alloys with many metals, giving them greater hardness, strength, heat resistance and corrosion resistance. One of its alloys, beryllium bronze, is a material that has made it possible to solve many complex technical problems.
Beryllium bronzes are alloys of copper with 1...3% beryllium. Unlike pure beryllium, they lend themselves well to mechanical processing; for example, they can be used to make ribbons with a thickness of only 0.1 mm. The tensile strength of these bronzes is greater than that of many alloy steels. Another remarkable detail: over time, most materials, including metals, “get tired” and lose strength. Beryllium bronzes are the opposite. As they age, their strength increases! They are non-magnetic. In addition, they do not spark upon impact. They are used to make springs, springs, shock absorbers, bearings, gears and many other products that require greater strength, good resistance to fatigue and corrosion, retention of elasticity over a wide temperature range, and high electrical and thermal conductivity characteristics. The aviation industry has become one of the consumers of this alloy: it is claimed that in a modern heavy aircraft there are more than a thousand parts made of beryllium bronze.
Beryllium additives enhance aluminum and magnesium based alloys. This is understandable: the density of beryllium is only 1.82 g/cm 3, and the melting point is twice as high as that of these metals. The most small quantities beryllium (0.005% is sufficient) greatly reduces the losses of magnesium alloys from combustion and oxidation during melting and casting. At the same time, the quality of castings improves and the technology is significantly simplified.
It turned out that with the help of beryllium it is possible to increase the strength, rigidity and heat resistance of other metals, not only by introducing it into certain alloys. To prevent rapid wear of steel parts, they are sometimes beryllized - their surface is saturated with beryllium by diffusion. This is done like this: a steel part is dipped into beryllium powder and kept in it at 900...1100°C for 10...15 hours. The surface of the part is coated with a solid chemical compound of beryllium with iron and carbon. This durable shell with a thickness of only 0.15...0.4 mm gives the parts heat resistance and resistance to sea water and nitric acid.
Beryllides, intermetallic compounds of beryllium with tantalum, niobium, zirconium and other refractory metals, also have interesting properties. Beryllides have exceptional hardness and resistance to oxidation. The best technical characteristics beryllides are supported by the fact that they can operate for more than 10 hours at a temperature of 1650°C.
Beryllium from a physicist's point of view
In the history of many elements there are special milestones - discoveries, after which the importance of these elements increases immeasurably. In the history of beryllium, such an event was the discovery of the neutron.
In the early 30s, German physicists W. Bothe and G. Becker, bombarding beryllium with alpha particles, noticed the so-called beryllium radiation - very weak, but extremely penetrating. It, as was later proven, turned out to be a stream of neutrons. And even later, this property of beryllium formed the basis of “neutron guns” - neutron sources used in different areas science and technology.
This marked the beginning of the study of the atomic structure of beryllium. It turned out that it is distinguished by a small cross section for neutron capture and a large cross section for their scattering. In other words, beryllium (as well as its oxide) scatters neutrons, changes the direction of their movement and slows down their speed to such values that chain reaction can proceed more efficiently. Of all hard materials Beryllium is considered the best neutron moderator.
In addition, beryllium can act as a neutron reflector: change their direction, return neutrons to the reactor core, and counteract their leakage. Beryllium is also characterized by significant radiation resistance, which persists even at very high temperatures.
The use of beryllium in nuclear technology is based on all these properties - it is one of the most necessary elements for it.
Moderators and reflectors made of beryllium and its oxide make it possible to significantly reduce the size of the reactor core, increase the operating temperature and use nuclear fuel more efficiently. Therefore, despite the high cost of beryllium, its use is considered economically justified, especially in small power reactors for aircraft and sea vessels.
Beryllium oxide has become an important material for the manufacture of claddings of fuel elements (fuel rods) of nuclear reactors. In fuel rods the neutron flux density is especially high; they contain the highest temperatures, the highest stresses and all the conditions for corrosion. Since uranium is corrosion unstable and not strong enough, it has to be protected with special shells, usually made of BeO.
High thermal conductivity (4 times higher than steel), high heat capacity and heat resistance make it possible to use beryllium and its compounds in heat-protective structures of spacecraft. The external thermal protection of the capsule of the Friendship 7 spacecraft, on which John Glenn was the first American cosmonaut to make an orbital flight (after Yuri Gagarin and German Titov), was made from beryllium.
In yet to a greater extent space technology What attracts people in beryllium is its lightness, strength, rigidity, and especially its unusually high strength-to-weight ratio. Therefore, beryllium and its alloys are increasingly used in space, rocket and aviation technology.
In particular, due to the ability to maintain high accuracy and dimensional stability, beryllium parts are used in gyroscopes - devices included in the orientation and stabilization system of rockets, spacecraft and artificial satellites Earth.
Element #4 also applies to other areas modern technology, including in radio electronics. In particular, ceramics based on beryllium oxide became the material for the housings of the so-called traveling wave lamps - very efficient radio tubes that have not lost their value under the onslaught of semiconductors.
In X-ray technology, beryllium metal has provided excellent windows for x-ray tubes: thanks to its low atomic weight, it allows 17 times more soft materials to pass through x-rays than aluminum of the same thickness.
Beryllium from a chemist's point of view
Typically amphoteric, i.e. It has the properties of both a metal and a non-metal. However metallic properties still prevail.
Beryllium does not react with hydrogen even when heated to 1000°C, but it easily combines with halogens, sulfur and carbon. From beryllium halides highest value have its fluoride and chloride, used in the process of processing beryllium ores.
Beryllium dissolves well in all mineral acids, except, oddly enough, nitric acid. From it, as from oxygen, beryllium is protected by an oxide film.
Beryllium oxide (BeO) has valuable properties and in some cases competes with beryllium itself.
High refractoriness (melting point 2570°C), significant chemical resistance and high thermal conductivity make it possible to use beryllium oxide in many branches of technology, in particular for the lining of coreless induction furnaces and crucibles for melting various metals and alloys. Interestingly, beryllium oxide is completely inert towards beryllium metal. This is the only material from which crucibles are made for melting beryllium in a vacuum.
Beryllium oxide has been used in glass production for a relatively long time. Its additives increase density, hardness, refractive index and chemical resistance glass Using beryllium oxide, special glasses are created that are highly transparent to ultraviolet and infrared rays.
Fiberglass, which contains beryllium oxide, can be used in the construction of missiles and submarines.
When beryllium burns, a lot of heat is released - 15 thousand kcal/kg. Therefore, beryllium can be a component of high-energy rocket fuel.
Some beryllium compounds serve as catalysts chemical processes. Beryllium reacts with alkalis to form beryllate salts, similar to aluminates. Many of them have a sweetish taste, but you cannot taste them on your tongue - almost all beryllates are poisonous.
Many scientists believe that beryllium isotopes 10Be and 7Be are formed not in the bowels of the earth, but in the atmosphere as a result of the action of cosmic rays on nitrogen and oxygen nuclei. Minor traces of these isotopes have been found in rain, snow, air, meteorites and marine sediments.
However, if you put together all the 10 Be found in the atmosphere, water basins, soil and on the ocean floor, you get a rather impressive figure - about 800 tons.
The 10 Be isotope (half-life 2.5 10 6 years) is of exceptional interest for geochemistry and nuclear meteorology. Born in the atmosphere, at an altitude of approximately 25 km, 10 Be atoms, along with precipitation, fall into the ocean and settle at the bottom. Knowing the concentration of 10 Be in a sample taken from the bottom and the half-life of this isotope, it is possible to calculate the age of any layer on the ocean floor.
Beryllium-10 also accumulates in marine silts and fossil bones (bones absorb beryllium from natural waters). In this regard, an assumption arose about the possibility of determining the age of organic remains using 10Be. The fact is that the fairly widely developed radiocarbon dating unsuitable for determining the age of samples in the range of 10 5 ...10 8 years (due to the large difference between the half-lives of 14 C and the long-lived isotopes 40 K, 82 Rb, 232 Th, 235 U and 238 U). The 10 Be isotope “fills” this gap.
The life of another radioisotope, beryllium-7, is much shorter: its half-life is only 53 days. Therefore, it is not surprising that its amount on Earth is measured in grams. The 7Be isotope can also be produced in a cyclotron, but this will be expensive. Therefore, this isotope has not received widespread use. It is sometimes used for weather forecasting. It acts as a kind of “marker” of air layers: by observing the change in the concentration of 7 Be, one can determine the period of time from the beginning of the movement of air masses. 7 Be is used even less frequently in other studies: chemists - as a radioactive tracer, biologists - to study the possibilities of combating the toxicity of beryllium itself.
Beryllium from the point of view of a biologist and physician
Beryllium is found in plants growing on beryllium-containing soils, as well as in the tissues and bones of animals. But while beryllium is harmless to plants, it causes so-called beryllium rickets in animals. An increased content of beryllium salts in food promotes the formation of soluble beryllium phosphate in the body. By constantly “stealing” phosphates, beryllium thereby contributes to the weakening bone tissue- this is the cause of the disease.
Many beryllium compounds are poisonous. They can cause inflammatory processes on the skin and beryllium, a specific disease caused by inhalation of beryllium and its compounds. Short-term inhalation of large concentrations of soluble beryllium compounds causes acute berylliosis, which is an irritation respiratory tract, sometimes accompanied by pulmonary edema and suffocation. There is also a chronic type of berylliosis. It is characterized by less severe symptoms, but greater disturbances in the functions of the entire body.
The permissible limits for beryllium content in the air are very small - only 0.001 mg/m3. This is significantly less acceptable standards for most metals, even toxic ones like lead.
Most often used to treat berylliosis chemical compounds, binding beryllium ions and facilitating their removal from the body.
Three “buts” of beryllium
This chapter does not mean that everything previous is just “theory”. But, unfortunately, the factors limiting the use of beryllium are quite real, and they cannot be ignored.
This is primarily the fragility of the metal. It greatly complicates the process of its mechanical processing and makes it difficult to obtain large sheets of beryllium and complex profiles required in certain structures. Efforts are being made to eliminate this deficiency. But, despite some successes (production of high-purity metal, various technological improvements), obtaining ductile beryllium continues to be a difficult problem.
The second is the toxicity of beryllium.
Careful control over air purity, special ventilation systems, and possibly greater automation of production - all this makes it possible to successfully combat the toxicity of element No. 4 and its compounds.
And finally, the third and very important “but” of beryllium is its high cost. The price of 1 kg of beryllium in the USA is now about 150 dollars, i.e. Beryllium is several times more expensive than titanium.
However, increased consumption always leads to technological improvements, which in turn help reduce production costs and prices. In the future, the demand for beryllium will increase even more: after all, humanity began to use this metal a little more than 40 years ago. And, of course, the advantages of element No. 4 will prevail over its disadvantages.
From documents of the past
The eighties of the last century were a time of lively scientific debate about the atomic weight of beryllium.
DI. Mendeleev wrote about this:
“The misunderstanding lasted for several years. More than once I have heard that the question of the atomic weight of beryllium threatens to shake the generality of the periodic law and may require profound transformations in it. Many forces took part in the scientific controversy concerning beryllium, of course, precisely because the matter was about a subject more significant than the atomicity of a relatively rare element; the periodic law was explained in these different languages, and the mutual connection of the elements different groups has become more obvious than ever.".
For a long time, the main opponents of two-valence beryllium were Swedish chemists Professor L.F. Nilsson and O. Peterson. In 1878, they published an article “On the preparation and valency of beryllium”, at the end of which there were the following words: “... our opinion about the true atomic weight and chemical nature of this metal contradicts the so-called periodic law, which Mendeleev intended for all elements, namely not only because with Be = 13.8 this metal can hardly be placed in the Mendeleev system, but also because then an element with an atomic weight of 9 ,2, as required by the periodic law, would be absent from the system and, apparently, still needs to be discovered.”
The periodic law was defended by the Czech chemist Boguslav Brauner, who believed that the well-known law of Dulong and Petit, which was used by Swedish chemists, has some deviations in the region of low atomic weights, to which beryllium actually belongs. In addition, Brauner advised Nilsson and Peterson to determine the vapor density of beryllium chloride, believing that the quantitative determination of this characteristic would help to accurately establish the element’s belonging to one or another group of the periodic table. When Swedish chemists repeated their experiments and did what Brauner advised them, they were convinced that Mendeleev was right. In an article reflecting the results of this work, Nilsson and Peterson wrote: “... we must abandon our previously defended opinion that beryllium is a trivalent element... At the same time, we recognize the correctness of the periodic law in this important case.”
In 1884, Nilsson wrote to Mendeleev: “... I cannot help but express to you my heartfelt congratulations on the fact that in this case, as in many others, the system has justified itself.”
Later, in one of the editions of “Fundamentals of Chemistry” D.I. Mendeleev noted that “Nilsson and Peterson are one of the main defenders of the triatomicity of beryllium... provided experimental evidence in favor of the diatomicity of beryllium and, having loudly expressed this, showed that in science, the truth, even with different languages, is equally dear to everyone, at least at first was denied by those who approved it.”
Precious beryls
The main mineral of beryllium, beryl, is known to be a semi-precious stone. But when they talk about its four varieties - emerald, aquamarine, sparrow and heliodor, the prefix “semi” is discarded. Emeralds, especially those weighing more than 5 carats, are valued no less than diamonds.
How are these stones different from ordinary beryl? After all, their formula is the same - Al 2 Be 3 (Si 6 O 18). But this formula does not take into account impurities, which, in fact, turn semi-precious stones into precious ones. Aquamarine is colored with ferrous iron ions; in emerald (also known as emerald), in addition to Fe 2+, there is a slight admixture of chromium oxide. Pink Vorobyovite is explained by the admixture of cesium, rubidium and divalent manganese compounds, and the golden-yellow heliodor is colored by ferric ions.
Precious metal from semi-precious stone
The high cost of beryllium is explained not only by limited raw material resources, but also by the difficulties of the technology for obtaining pure metal. The main method for producing beryllium is the reduction of its fluoride with magnesium metal. Fluoride is obtained from hydroxide, and hydroxide from beryl concentrate. Already the first run of this technological ladder consists of several steps: the concentrate is subjected to heat treatment, grinding, then it is successively treated with sulfuric acid, water, solutions of ammonia and caustic soda, and special complexing agents.
The resulting sodium beryllate is hydrolyzed and the hydroxide is separated in a centrifuge.
Hydroxide also turns into fluoride only after several operations, each of which is quite complex and labor-intensive. Magnesium reduction occurs at a temperature of 900°C, the progress of the process is carefully controlled. Important detail: The heat released in a reaction is absorbed at the same rate as it is released. The resulting liquid metal is poured into graphite molds, but it is contaminated with slag and is therefore melted again in a vacuum.
Beryllium in everyday life
The areas of application of beryllium are not limited to “high” technology. Products made from nickel-beryllium alloys (Be content does not exceed 1.5%) can also be found in everyday life. Surgical instruments, hypodermic needles, and cast metal teeth are made from these alloys. Springs for watches are made from the alloy “elinvar” (nickel, beryllium, tungsten) in Switzerland. In the United States, copper-beryllium alloy is used to make sleeves for the writing mechanism of ballpoint pens.
Artificial emeralds
Get emeralds artificially much harder than most precious stones. Main reason The fact is that beryl is a complex compound. However, scientists were able to imitate natural conditions, in which the mineral was formed: emeralds are “born” at very high blood pressure(150 thousand atm.) and high temperature (1550°C). Artificial emeralds can be used in electronics.
Beryllium and superconductivity
More than a thousand materials are now known that acquire at temperatures close to absolute zero, property of superconductivity. Among them is the metal beryllium. When condensed as a thin film onto a cold substrate, beryllium becomes a superconductor at a temperature of about 8 K.
Beryllium in a medicinal product
In 1964, a group of Soviet chemists led by the vice-president of the Academy of Sciences of the Tajik SSR, Doctor of Chemical Sciences K.T. Poroshin held chemical analysis ancient healing remedy "mummy". It turned out that this substance complex composition, and among the many elements contained in mumiyo is beryllium.
Geography of beryllium deposits
Beryllium raw materials are available in many countries around the world. Most large deposits its located in Brazil and Argentina. They account for approximately 40% of beryl production in capitalist countries. Significant reserves of beryllium ores are also found in African countries and India.
Until recently, coarse-grained beryl was mined by hand. In Brazil, up to 3,000 tons of concentrate are still extracted annually using this artisanal method.
Only recently have new flotation methods been proposed to exploit previously unprofitable deposits of fine-grained beryl.
Beryllium and the “atomic needle”
The thermal insulation properties of beryllium oxide can also be useful in research earthly depths. Thus, there is a project to take samples from the Earth’s mantle from depths of up to 32 km using the so-called atomic needle. This is a miniature nuclear reactor with a diameter of only 60 cm. The reactor must be enclosed in a thermally insulating beryllium oxide casing with a heavy tungsten tip.
The principle of operation of the atomic needle is as follows: the high temperatures created in the reactor (over 1100°C) will cause the melting of rocks and the movement of the reactor towards the center of the Earth. At a depth of approximately 32 km, the heavy tungsten tip should separate, and the reactor, becoming lighter than the surrounding rocks, will take samples from depths that are still unattainable and “float” to the surface.
Beryllium (lat. Beryllium), Be, chemical element Group II of the Mendeleev periodic system, atomic number 4, atomic mass 9.0122; lightweight light gray metal. It has one stable isotope, Be.
Beryllium was discovered in 1798 in the form of BeO oxide, isolated from the mineral beryl by L. Vauquelin. Metallic beryllium was first obtained in 1828 by F. Wöhler and A. Bussy independently of each other. Since some beryllium salts have a sweet taste, it was first called “glucinium” (from the Greek glykys - sweet) or “glycium”. The name Glicinium is used (along with Beryllium) only in France. The use of beryllium began in the 40s of the 20th century, although its valuable properties as a component of alloys were discovered even earlier, and its remarkable nuclear properties were discovered in the early 30s of the 20th century.
Distribution of beryllium in nature. Beryllium is a rare element. Beryllium is a typical lithophile element, characteristic of acidic, subalkaline and alkaline magmas. About 40 beryllium minerals are known. Of these, the largest practical significance has beryl, phenacite, helvin, chrysoberyl, bertrandite are promising and partially used.
Physical properties. Beryllium crystal lattice is hexagonal, close-packed. Beryllium is lighter than aluminum, its density is 1847.7 kg/m3 (for Al it is about 2700 kg/m3), its melting point is 1285°C, and its boiling point is 2470°C.
Beryllium was discovered in 1798 by L. Vauquelin in the form of beryl earth (BeO oxide), when this French chemist was elucidating its general features chemical composition beryl and emerald gemstones. Metallic beryllium was obtained in 1828 by F. Wöhler in Germany and, independently, by A. Bussy in France. However, due to impurities, it could not be fused. Only in 1898, the French chemist P. Lebeau, having subjected double fluoride of potassium and beryllium to electrolysis, obtained sufficiently pure metal crystals of beryllium. Interestingly, due to the sweet taste of water-soluble beryllium compounds, the element was first called “glucinium” (from the Greek glykys - sweet). Because of the similar properties of beryllium and aluminum, it was thought to be a trivalent metal with an atomic mass of 13.5. This error was corrected by D.I. Mendeleev, who, based on the pattern of changes in the properties of elements in a period, assigned beryllium a place in the second group.
Being in nature, receiving:
Beryllium is a rare element; its content in the earth's crust is 2.6·10 -4% by mass. Sea water contains up to 6·10 -7 mg/l of beryllium. The main natural minerals containing beryllium: beryl Be 3 Al 2 (SiO 3) 6, phenacite Be 2 SiO 4, bertrandite Be 4 Si 2 O 8 ·H 2 O and helvin (Mn,Fe,Zn) 4 3 S. Colored by impurities cations of other metals, transparent varieties of beryl - precious stones, for example, green emerald, blue aquamarine, helioder, sparrow and others. Currently, they have learned to synthesize them artificially.
In the form of a simple substance in the 19th century, beryllium was obtained by the action of potassium on anhydrous beryllium chloride:
BeCl 2 +2K=Be+2KCl.
Currently, beryllium is obtained by reducing its fluoride with magnesium:
BeF 2 +Mg=Be+MgF 2
or by electrolysis of a melt of a mixture of beryllium and sodium chlorides. The original beryllium salts are isolated during the processing of beryllium ore.
Physical properties:
Beryllium metal is a hard, brittle, gray metal. In air, beryllium, like aluminum, is covered with an oxide film, giving it a matte color. Melting point 1278°C, boiling point about 2470°C, density 1.816 kg/m3. Stable up to 1277°C a-Be (magnesium (Mg) type hexagonal lattice, parameters a = 0.22855 nm, c = 0.35833 nm), at temperatures preceding the melting of the metal (1277-1288°C) - b-Ve with a cubic lattice.
Chemical properties:
The presence of an oxide film protects the metal from further destruction and causes its low chemical activity at room temperature. When heated, beryllium burns in air to form BeO oxide and reacts with sulfur and nitrogen. Beryllium reacts with halogens at ordinary temperatures or at low heat. All these reactions are accompanied by the release large quantity warmth, since strength crystal lattices of emerging compounds (BeO, BeS, Be 3 N 2, BeCl 2, etc.) is quite large.
Due to the formation of a strong film on the surface, beryllium does not react with water, although it is located significantly to the left of hydrogen in the series of standard potentials. Like aluminum, beryllium reacts with acids and alkali solutions:
Be + 2HCl = BeCl 2 + H 2,
Be + 2NaOH + 2H 2 O = Na 2 + H 2.
Interestingly, beryllium dissolves well in concentrated fluoride solutions:
Be + 4NH 4 F + 2H 2 O = (NH 4) 2 + 2NH 3 *H 2 O + H 2
The reason is the formation of strong fluoride complexes.
The most important connections:
Beryllium oxide, BeO occurs naturally as the rare mineral bromellite. Receive thermal decomposition beryllium sulfate or hydroxide above 800°C. A high-purity product is formed by the decomposition of basic acetate above 600°C.
Uncalcined beryllium oxide is hygroscopic, adsorbs up to 34% of water, and calcined at 1500 ° C - only 0.18%. Beryllium oxide, calcined above 500°C, easily interacts with acids, more difficult with alkali solutions, and calcined above 727°C - only with hydrofluoric acid, hot concentrated sulfuric acid and alkali melts. Resistant to molten lithium, sodium, potassium, nickel and iron.
Beryllium oxide has very high thermal conductivity. Considered one of the best refractory materials, used for making crucibles and other products
Beryllium hydroxide, Be(OH) 2 is a polymer compound insoluble in water. It exhibits amphoteric properties: Be(OH) 2 + 2KOH = K 2, Be(OH) 2 + 2HCl = BeCl 2 + 2H 2 O.
Effect on beryllium hydroxide Be(OH) 2 solutions carboxylic acids or by evaporating solutions of their beryllium salts, beryllium oxysalts are obtained, for example, Be 4 O(CH 3 COO) 6 oxyacetate.
Beryllium halides, colorless christ. substances dissolve in the air, absorbing moisture. To obtain anhydrous chloride, the reaction 2BeO + CCl 4 = 2BeCl 2 + CO 2 is used
Like aluminum chloride, BeCl 2 is a catalyst in the Friedel–Crafts reaction. Subjects to hydrolysis in solutions
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beryllates, in concentrated solutions and melts of alkalis there are beryllates of the composition M 2 BeO 2, M 3 BeO 4, in dilute solutions there are hydroxoberyllates M 2. Easily hydrolyze to beryllium hydroxide.
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Beryllium hydride, BeH 2 is a polymer substance, it is obtained by the reaction: BeCl 2 + 2LiH = BeH 2 + 2LiCl
Beryllium carbide, Be 2 C - is formed by the interaction of beryllium with carbon. Like aluminum carbide, it is hydrolyzed by water to form methane.
Application:
Beryllium is mainly used as an alloying additive to various alloys. The addition of beryllium significantly increases the hardness and strength of the alloys, and the corrosion resistance of the surfaces of products made from these alloys. Beryllium bronze (Cu and 3-6% Be) is a material for springs with great resistance to mechanical fatigue and absolutely no sparks during mechanical shocks.
Beryllium weakly absorbs X-rays, so the windows of X-ray tubes (through which the radiation escapes) are made from it.
IN nuclear reactors Neutron reflectors are made from beryllium; it is used as a neutron moderator.
In mixtures with some a-radioactive nuclides beryllium is used in ampoule neutron sources, since during the interaction of beryllium-9 and a-particles produce neutrons: 9 Be( a,n) 12 C.
Physiological action: In living organisms, beryllium apparently has no biological function, but beryllium can replace magnesium in some enzymes, which leads to disruption of their function. Volatile and soluble beryllium compounds, as well as dust containing beryllium and its compounds, are very toxic and carcinogenic (MPC 0.001 mg/m3).
Rudakova Anna Valerievna
HF Tyumen State University, 561 group.
Sources:
Beryllium // Wikipedia. Update date: 01/23/2019. URL: https://ru.wikipedia.org/?oldid=97664788 (access date: 02/04/2019).
Beryllium is a silvery-gray metal with shiny crystalline manifestations when broken, and is the fourth chemical element on the periodic table. The weight of a beryllium atom is 9.0122 in standard units atomic mass, equal to 1/12 of the mass of the carbon isotope. Beryllium is a rare earth metal that is related to the mass of earth in percentage 2.6·10-4%.
Discovery of Beryllium
Like many chemical elements, beryllium was discovered in connection with the study of the properties noble metals and precious stones. In 1798, the famous French Louis Nicolas Vauquelin worked with beryl - a semi-precious stone, the closest “relative” of emerald. During the experiments, the so-called beryl earth, which contained beryllium oxide BeO. However, this time beryllium as an autonomous chemical element was not identified and named. This happened later, in 1828, when the German scientist Friedrich Wöller managed to obtain beryllium metal. And the evolution of knowledge of this rather rare element was completed by the French chemist Lebeau, who, using electrolysis, managed to obtain pure beryllium crystals.
Beryllium crystals have a sweetish taste, which is why the element was originally called “glucinium” from the Greek for “sweet”. With the discovery of beryllium, a new industry- synthesis of semi-precious and precious stones. Today, beryl is used to synthesize artificial emeralds, aquamarines, and heliodors, which are actively used in the jewelry industry. The semi-precious stone beryl, which served as the starting point for the discovery of beryllium, was named after the South Indian city of Vellur, which was located near the famous emerald mines of India. Beryllium is also found in human body in an amount not exceeding 0.036 mg. However, beryllium gas and beryllium dust are highly toxic substances that cause serious pathologies of the respiratory and circulatory system.
Basic physical and chemical properties
Thanks to the highest internal heat of power, this metal has unique characteristics that determine its demand in leading industries and science. The aforementioned rarity of beryllium in nature makes this element somewhat of a shortage in the world of modern metal alloys.
Relatively low temperature melting temperature of 1284°C makes it possible to create beryllium ingots under vacuum conditions, but the most common practice is to produce beryllium in a powdered state. Cast beryllium is characterized by a highly fragile structure, so this metal is of greatest interest in its deformed form. Heat treatment under pressure makes it possible to increase the structural strength of beryllium by an order of magnitude, which in the final state, due to its high ductility, becomes similar in many characteristics to magnesium and aluminum. In particular, beryllium outdoors also form an oxide film that prevents corrosion. This metal easily dissolves in many acids and even alkalis, with the exception of concentrated nitric acid.
Beryllium is obtained by isolating it from aluminum alloys using a variety of purification technologies, as well as from beryl minerals, which are exposed to concentrated sulfuric acid. Beryllium metal is produced by treating beryllium oxides and sulfates (Be(OH)2 or BeSO4). Technological processes Beryllium production is quite complex and requires significant energy consumption, so this metal is an expensive material.
Scope of application
Unique natural property beryllium - do not interact with x-ray radiation determined the active use of this metal in the manufacture of X-ray devices and equipment.
In addition, today beryllium alloys are used for the manufacture of neutron reflectors and moderators in nuclear reactors. Beryllium oxide has extremely high thermal conductivity and fire resistance, which is also used in the production of equipment for nuclear energy.
Aerospace and aviation are two other industries where successful application strength, anti-corrosion and fire resistance of beryllium alloys. In metallurgy, beryllium is used as an alloying element that increases the anti-corrosion and structural strength of steel.
