Environmental pollution with beryllium is also associated with industrial development. Beryllium serves as a source of neutrons in nuclear reactors. Where the concentration of this element reaches 0.01 mg per 1 m3 of air, signs of poisoning may appear; three stages are distinguished:
- foundry workers' fever, which goes away in 24-48 hours;
- toxic pneumonia, which can appear even several years after beryllium poisoning;
- chronic beryllium poisoning - berylliosis, or industrial pulmonary sarcoidosis.
Statistics show that for every 100 such poisonings, there are usually 10 deaths.
Beryllium belongs to non-radioactive elements. But its use has recently increased by about 500% (while the use of boron has increased by 78%, chromium by 50%, copper by 30%, manganese by 45%, nickel by 70%, zinc by 44%).
Beryllium is a rare element on our planet. It has many valuable properties: it is very light (4.5 times lighter than iron) and under certain conditions it becomes a rich source of neutrons. Thus, Enrico Fermi used radium and beryllium preparations in experiments that gave the world the first reactor. Beryllium does not rust!
For many years, beryllium along with zinc was filled with colored street lamps, the light of which, as it turned out later, was harmful.
And one more property of beryllium: its powder, constantly used in fuel mixtures for rockets, releases a large amount of energy when burned. But all its advantages are outweighed by one drawback: beryllium is poisonous even in the most minimum quantities. It has a detrimental effect on sexual functions.
The intensive use of beryllium in industry, including defense, seriously worries doctors, nutritionists, and the country's population.
Beryllium in the body
Beryllium is a toxic chemical element. Beryllium can enter the human body both with food and through the lungs. The average daily intake of beryllium is 10-20 mcg. When entering the gastrointestinal tract in soluble form, beryllium interacts with phosphates and forms the poorly soluble compound Be3(PO4)2 or is bound by epithelial cell proteins into strong proteinates. Therefore, the absorption of beryllium in the gastrointestinal tract intestinal tract is small and ranges from 4 to 10% of the incoming amount. This indicator also depends on acidity gastric juice. Total quantity beryllium in the adult human body ranges from 0.4 to 40 mcg. Beryllium is constantly present in the blood, bone and muscle tissue (0.001-0.003 μg/g) and other organs. It has been established that beryllium can be deposited in the lungs, liver, lymph nodes, bones, and myocardium. Beryllium is excreted from the body mainly through urine (more than 90%).
Beryllium can take part in the regulation of phosphorus-calcium metabolism and maintaining the immune status of the body. It has been established that the activity of beryllium compounds is clearly manifested in various biochemical transformations associated with the participation of inorganic phosphates.
An increased content of beryllium in food promotes the formation of beryllium phosphate. By systematically “taking” phosphates from the most important part of the bones, calcium phosphate, beryllium thereby weakens bone tissue and contributes to its destruction. It is known experimentally that the introduction of this element to animals causes “beryllium” rickets.
It has been proven that even a small amount of beryllium in bones leads to their softening (beryllosis). In places parenteral administration beryllium destroys surrounding tissues, from here beryllium is excreted very slowly. Ultimately, beryllium is deposited in the skeleton and liver.
By modern ideas Beryllium is a toxic, carcinogenic and mutagenic element. The pathogenic effect of beryllium is observed when it is inhaled in concentrations that exceed the MPC by 2 or more times. Beryllium salts at a concentration of 1 µmol/l specifically inhibit the activity of alkaline phosphatase and have a depressing effect on other enzymes. The immunotoxic properties of beryllium have been studied quite well. In pathology, acute and chronic beryllium poisoning are distinguished. It is known, for example, that the elimination of beryllium compounds from the body (especially from the organs of the lymphoid system, where they accumulate) occurs extremely slowly, over a period of more than 10 years. Increased level beryllium is found in the families of workers who come into contact with this element at work.
Signs of excess beryllium in the body
- damage to lung tissue (fibrosis, sarcoidosis);
- skin lesions - eczema, erythema, dermatosis (from contact of beryllium compounds with skin);
- berylliosis;
- foundry fever (irritation of the mucous membranes of the eyes and respiratory tract);
- erosion of the mucous membranes of the gastrointestinal tract;
- dysfunction of the myocardium, liver;
- development of autoimmune processes, tumors.
To prevent the development of pathology caused by contact with beryllium compounds in industrial conditions, it is necessary to strictly adhere to safety rules (use of a respirator, change of clothes, etc.), and eliminate the effect of possible irritants on the body (nicotine, cold dry air, sprays). At a certain stage of pathology development, it may be necessary to change jobs.
Was open French chemist Louis Nicolas Vauquelin in 1798. Also, this element, its compounds and minerals were studied by the Russian chemist I.V. Avdeev.
The name beryllium comes from the ancient Greek name for the mineral beryl, which in turn comes from the name of the city of Belur in India. At first, this element was called “glucinium”, which is translated from ancient Greek as sweet. This was due to the sweet taste of water-soluble beryllium compounds.
Beryllium in the human body
Beryllium is considered a rather rare element. It has a toxic, carcinogenic and mutagenic effect on the body of animals and humans. It enters the human body with air and food. On average, 10-20 mcg of beryllium enters our body per day. Entering the gastrointestinal tract in soluble form, beryllium interacts with phosphates. As a result, a poorly soluble compound Be3(PO4)2 is formed. Beryllium is also capable of binding to proteins of epithelial cells into strong proteinates. IN gastrointestinal the tract absorbs a little beryllium - from 4 to 10%. The percentage of absorption also depends on the acidity of gastric juice.
On average, the human body contains 0.4 - 40 mcg of beryllium. It is concentrated mainly in the bone and muscle tissue, blood and other organs.
Beryllium is deposited in the liver, lungs, bones, lymph nodes and myocardium. It is excreted from the body mainly through urine (about 90%). Beryllium is involved in the regulation of phosphorus-calcium metabolism and maintains the immune status of the body. When excessive amounts of beryllium are consumed, beryllium phosphate is formed. It can weaken and destroy bone tissue, negatively affecting calcium. Beryllium has the ability to replace magnesium in some enzymes, disrupting their function.
According to research, the introduction of beryllium to animals provokes the development of “beryllium” rickets. Even a small amount of this element in the bones leads to their softening (beryllosis). Beryllium is released from the body very slowly, over 10 years. Industrial workers are at risk of beryllium poisoning.
Symptoms of overexcess beryllium in the body:
- lung damage (sarcoidosis, fibrosis);
- dysfunction of the heart and liver;
- skin lesions - dermatosis, eczema, erythema;
- berylliosis;
- irritation of the respiratory tract and mucous membranes of the eyes);
- erosion of the mucous membranes of the stomach and intestines;
- the occurrence of autoimmune processes and tumors.
To prevent beryllium poisoning at work, it is necessary to take precautions, namely use a respirator, wear a change of clothes, etc. Should also be avoided negative impact the body from irritants such as sprays, cold dry air and nicotine. IN as a last resort In case of intoxication, it is necessary to change jobs.
Bone Breaker
Beryllium refers to toxic ultramicroelements. Physiological role beryllium in the human body has not been sufficiently studied, but it is known that beryllium can participate in the regulation of phosphorus-calcium metabolism and support of the body’s immune status.
Daily requirement of the human body has not been precisely established, but there is evidence that the optimal average daily intake of beryllium is 10–20 mcg.
Beryllium can enter the human body both with food and through the lungs. When introduced in a soluble form into the gastrointestinal tract, beryllium interacts with phosphates and forms poorly soluble Be 3 (PO 4) 2 or binds to proteins of epithelial cells into strong proteinates. Therefore, the absorption of beryllium in the gastrointestinal tract is low and ranges from 4 to 10% of the ingested amount. It should be noted that this indicator also depends on the acidity of gastric juice.
The total amount of beryllium in the body of an adult varies (according to various sources) from 0.4 to 40 mcg. Beryllium is constantly present in the blood, bone and muscle tissues (0.001–0.003 μg/g) and other organs. It has been established that beryllium can be deposited in the lungs, liver, lymph nodes, bones, and myocardium.
Beryllium is excreted from the body mainly through urine (more than 90%).
Biological role in the human body. Beryllium is mainly involved in the exchange of magnesium and phosphorus in tissue. It has been established that the activity of beryllium compounds is clearly manifested in various biochemical transformations associated with the participation of inorganic phosphates.
The effect of beryllium on the body is multifaceted. Today, its toxic (including cytotoxic), sensitizing, embryotoxic and carcinogenic effects have been proven. The latter was established in an animal experiment certain types and is discussed in relation to man. Beryllium and its compounds have the ability to penetrate into all organs, cells and their nuclei, into cellular organelles, in particular into mitochondria. He damages cell membranes , including - and their lipid components , disrupting microviscosity. Beryllium inhibits the activity of ATPase of the sarcoplasmic reticulum by inhibiting the transport of magnesium and calcium.
Penetrating into the nuclei of cells, beryllium reduces the activity of DNA synthesis enzymes, in particular DNA polymerase; there are indications of the importance of DNA synthesis disorders for the appearance of abnormal proteins that play the role of autoantigens.
The cytotoxic effect of beryllium compounds has been studied on phagocytes. In particular, the introduction of beryllium sulfate and citrate causes a blockade of cells of the mononuclear phagocyte system and reduces the phagocytosis index by 65–75%. Administration of beryllium phosphate suppresses the inflammatory response .
With intratracheal administration of beryllium compounds, an increased release of macrophages and polynuclear cells into the lumen of the alveoli occurs. However, the mobility of macrophages decreases, their organelles are damaged and DNA synthesis decreases.
It has been shown that during inhalation of soluble beryllium salts, connective tissue grows mainly in the perivascular and peribronchial zones. Fibrosis develops in response to the penetration of beryllium into the lungs, and this process has maximum speed during the first month after intratracheal administration of beryllium hydroxide. Sclerosis of the lung tissue, as a rule, is combined with the appearance of peculiar granulomas. Electron microscopic and histochemical studies recent years showed their similarity with granulomas of an allergic nature. It has been proven that the number of organelles in granuloma lymphocytes is increased. This fact and the presence of a large number of free ribosomes indicate their active state. Epithelioid granuloma cells arise from mononuclear cells and lymphocytes. Already in the first months after inhalation of soluble beryllium compounds, granuloma-like nodules develop, consisting of lymphoid-histiocytic elements. In the center of such nodules, disintegrating macrophages and cellular debris are found. This is interpreted as a result of the release of beryllium during the death of macrophages that absorbed it.
Beryllium synergists and antagonists. The antagonist of beryllium is magnesium. Magnesium in the body is mainly found inside cells, where it forms compounds with proteins and nucleic acids, containing Mg–N and Mg–O bonds. Similarities physical and chemical characteristics Be 2+ and Mg 2+ ions determine their ability to mutually substitute in such compounds. This explains, in particular, the inhibition of magnesium-containing enzymes when beryllium enters the body.
Signs of beryllium deficiency. No scientific data available.
Increased beryllium content in food promotes the formation of beryllium phosphate. By systematically “taking away” phosphates from the most important part of bones – calcium phosphate – beryllium weakens and destroys bone tissue. It is known that the introduction of this element to animals causes "beryllium" rickets
. It has been established that even a small amount of beryllium in bones leads to their softening.
In places where beryllium is administered parenterally, destruction of surrounding tissue occurs, from here beryllium is excreted very slowly. Beryllium is eventually deposited in the skeleton and liver.
According to modern concepts, beryllium is toxic, carcinogenic and mutagenic element . The pathogenic effect of beryllium is observed when it is inhaled in concentrations exceeding the maximum permissible concentrations by 2 or more times. Beryllium salts at a concentration of 1 µmol/l specifically inhibit the activity of alkaline phosphatase and have a depressing effect on other enzymes. The immunotoxic properties of beryllium have been studied quite well.
In pathology, acute and chronic beryllium poisoning are distinguished. It is known, for example, that the elimination of beryllium compounds from the body (especially from the organs of the lymphoid system, where they accumulate) occurs extremely slowly, over a period of more than 10 years. Elevated levels of beryllium occur in the families of workers exposed to this element at work.
The main manifestations of excess beryllium: damage to lung tissue (fibrosis, sarcoidosis), skin damage - eczema, erythema, dermatosis (from contact of beryllium compounds with skin), beryllium, foundry fever (irritation of the mucous membranes of the eyes and respiratory tract); erosion of the mucous membranes of the gastrointestinal tract, dysfunction of the myocardium, liver, development of autoimmune processes, tumors.
Beryllium is required: in ancient times beryl (aluminum and beryllium silicate) treated a huge number of female diseases. There was an opinion that with the help of beryl powder one could avoid uterine prolapse, toothache and headache, and beryllium bracelets protected against diseases of the ovaries and bladder. Modern lithotherapists recommend wearing beryl in case of disorders of the nervous system and chronic diseases of the respiratory system.
Food sources of beryllium: beryllium intake from food and water is insignificant; significant amounts accumulate in tomatoes and lettuce.
The main route of entry of beryllium into the body is inhalation, i.e. through the respiratory tract. People who work in environments where there is a risk of inhaling dust containing beryllium may develop an occupational disease - berylliosis
(beryllium or chemical pneumonia).
Beryllium (Latin Beryllium, denoted by the symbol Be) is an element with atomic number 4 and atomic mass 9.01218. Is an element main subgroup second group, second period periodic table chemical elements of Dmitry Ivanovich Mendeleev. At normal conditions beryllium is brittle, lightweight (its density is 1.846 g/cm3), a fairly hard metal of a light gray color.
In nature, there is only one stable isotope of this element - 9Be, other naturally occurring isotopes of element number four are radioactive - 7Be (half-life 53 days), 10Be (half-life 2.5 106 years). The 8Be isotope is absent in nature because it is extremely unstable and has a half-life of 10−18 seconds. What’s interesting is that beryllium is the only element in the periodic table that has only one stable isotope even in number.
Beryllium has been known to mankind since ancient times as beryllium-containing minerals - for thousands of years people have been searching for and developing deposits of aquamarines, emeralds and beryls. For example, there are references to the fact that even in the times of the pharaohs, emerald mines were developed in the Arabian desert. However, behind the attractive appearance of beryls, it was possible to “see” a new element only at the end of the 18th century. Beryllium was discovered as a new element in the form of beryl earth (BeO oxide) by the French chemist Louis Vauquelin in 1798. Metallic beryllium (in powder form) was first obtained by the action of metallic potassium on beryllium chloride in 1828 by Friedrich Wöhler and Antoine Bussy independently of each other, but the metal contained a very large amount of impurities. Pure beryllium was isolated only in 1898 by electrolysis of beryllium-sodium fluoride, done by P. Lebo.
Despite the fact that the element was discovered at the end of the 18th century, beryllium found real use only in the 40s of the 20th century. Element No. 4 is used as an alloying additive in copper, nickel, magnesium, iron and many other alloys. Beryllium bronzes are very durable and are used to make springs and other critical parts. Beryllium-nickel alloys are comparable in corrosion resistance, strength and elasticity to high-quality stainless steels, and sometimes even surpass them. Beryllium alloys are widely used in space, rocket and aviation technology. Beryllium is one of the best neutron moderators and reflectors in high-temperature nuclear reactors. Element #4 applies to other areas as well modern technology, including in radio electronics, mining, and X-ray engineering. Beryllium compounds have also found widespread use. For example, the oxide of this metal, BeO, is used in glass production and in the lining of induction furnaces. Some beryllium compounds act as catalysts in a number of chemical processes. In the future, beryllium is considered as a high-energy rocket fuel, since its combustion releases a colossal amount of heat (15,000 kcal/kg).
Beryllium is found in the tissues of many plants and animals. Although biological significance Scientists have yet to find out this element, but it has been established that it takes part in the exchange of magnesium and phosphorus in bone tissue. With an increased content of beryllium salts in the body, beryllium rickets begins to develop, leading to weakening and destruction of bones. Most compounds of element number four are poisonous. Many of them can cause inflammatory processes on the skin and beryllium - a specific disease caused by inhalation of beryllium and its compounds.
Biological properties
The biological role of beryllium has been poorly studied; it has only been established that this element is involved in the exchange of magnesium (Mg) and phosphorus (P) in bone tissue and plays a certain role in maintaining the immune status of the body. Beryllium is constantly present in the tissues of plants, animals and humans. The concentration of the fourth element in plant tissues directly depends on its percentage content in soils, in which the beryllium content ranges from 2∙10-4 to 1∙10-3%, while plant ash contains about 2∙10-4% of this element. In animals, beryllium is distributed in all organs and tissues; the content of element number four in bone ash ranges from 5∙10-4 to 7∙10-3%. Almost half of the beryllium absorbed by animals is excreted in the urine, a third is absorbed by the bones, and about 8% is concentrated in the liver and kidneys. An excess of beryllium in the diet of animals leads to the binding of phosphoric acid ions in the intestines into indigestible beryllium phosphate. As a result, a lack of phosphorus occurs and beryllium rickets, which cannot be cured by vitamin D, develops and is found in animals in biogeochemical provinces rich in beryllium. At the same time, beryllium is completely harmless to plants.
The beryllium content in the body of an average person (body weight 70 kg) is 0.036 mg. It is estimated that the daily intake of this element in the human body is about 0.01 mg. Beryllium enters the human body both with food and through the lungs. When entering the gastrointestinal tract in soluble form, beryllium interacts with phosphates and forms practically insoluble Be3(PO4)2 or is bound by epithelial cell proteins into strong proteinates. For this reason, the absorption of element number four in the gastrointestinal tract is low (4-10% of the incoming volume). In addition, a significant factor affecting the digestibility of beryllium in the gastrointestinal tract is the acidity of gastric juice. The fourth element of the periodic table is constantly present in the blood, bone and muscle tissues (0.001-0.003 mcg/g), and a number of other organs. It has been revealed that beryllium can accumulate in the liver, kidneys, lymph, lungs, bones and myocardium. The metal is excreted mainly in urine (about 90%). It has been established that in the human body the mechanism of action of beryllium is similar to the effect on the body of animals - even a small amount of this metal in the bones leads to their softening. In addition, beryllium salts at a concentration of 1 µmol/l are capable of inhibiting the activity of a number of enzymes (alkaline phosphatase, adenosine triphosphatase). Volatile and soluble beryllium compounds, as well as dust containing beryllium and its compounds, are very toxic, have allergic and carcinogenic effects, irritate the skin and mucous membranes, cause dermatoses, conjunctivitis, nasopharyngitis and other diseases of the skin and mucous membranes, diseases of the lungs and bronchi - tracheobronchitis , pneumonia and lung tumors. His presence in atmospheric air leads to a severe occupational respiratory disease - berylliosis (chemical pneumonitis). Short-term inhalation of large concentrations of soluble beryllium compounds causes acute beryllium, which is an irritation of the 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. It should be noted that these diseases can occur 10-15 years after stopping contact with beryllium!
It has been established that the removal of beryllium compounds from the body (especially from the organs of the lymphoid system, where they accumulate) occurs extremely slowly, over a period of more than 10 years. For this reason, chemical compounds that bind beryllium ions and promote their rapid removal from the body are most often used to treat berylliosis. The permissible limits for beryllium content in the air are very small - only 0.001 mg/m3, in drinking water 0.0002 mg/l.
A large number of scientists believe that beryllium isotopes 10Be and 7Be are formed not in the bowels of the earth, like other elements, but in the atmosphere as a result of the action of cosmic rays on nitrogen and oxygen nuclei. This theory can be confirmed by the detection of impurities of these isotopes in rain, snow, air, meteorites and marine sediments. Moreover, in total all 10Be found in the atmosphere, water basins (including in bottom sediments) and soil is about 800 tons. Originating in the atmosphere (at an altitude of 25 kilometers), 10Be atoms, along with precipitation, enter the ocean and settle at the bottom. 10Be concentrates in marine muds and fossil bones, which take up the metal from natural waters. Thus, knowing the concentration of 10Be 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. Theoretically, this should also apply to determining the age of organic remains. World famous and accepted by all radiocarbon dating not suitable for determining the age of samples in the range of 105-108 years (the whole point is the large difference between the half-lives of 14C and the long-lived isotopes 40K, 82Rb, 232Th, 235U and 238U). 10Be is able to fill this gap.
Another radioisotope of beryllium, 7Be, “lives” much longer short life(its half-life is only 53 days). For this reason, its amount on Earth is measured in grams, and its scope is limited to several specific purposes: in meteorology, by studying the concentration of this isotope, the time interval from the beginning of the movement of air masses is determined; in chemistry 7Be is used as a radioactive tracer; in medicine - to study the possibilities of combating the toxicity of beryllium itself.
Springs for watches are made from the alloy “elinvar” (nickel, beryllium, tungsten) in Switzerland. By the way, a curious episode from the history of the Second World War is connected with these Swiss springs. The industry of Nazi Germany was isolated from all major sources of beryllium raw materials; almost all world production of this valuable strategic metal was in the hands of the United States. The German leadership decided to use neutral Switzerland to smuggle beryllium bronze - soon American companies received orders from Swiss “watchmakers” for such a quantity that would be enough to supply watch springs to the whole world for five hundred years to come. Naturally, such a thinly veiled lie was caught and the order was not fulfilled, but still the latest brands Rapid-firing aircraft machine guns that entered service with the fascist army had springs made of beryllium bronze.
Despite the fact that beryllium is toxic chemical elements and many of its compounds are poisonous, this metal was discovered in one very famous healing agent. 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 conducted chemical analysis ancient healing remedy "mummy". As it turned out, this substance complex composition, and among the many elements contained in mumiyo is beryllium.
It turns out that emeralds are much more difficult to obtain artificially than most other gemstones. The fact is that beryl is a complex compound. And yet, scientists were able to imitate the natural conditions under which the mineral “emerges”: the process occurs at very high pressure (150 thousand atmospheres) and high temperature (1,550 °C). Emeralds obtained artificially can be used in electronics.
The Mining Museum of St. Petersburg has an interesting exhibit - a one and a half meter crystal of beryl. It is interesting not only for its impressive size, but also for its history. During the blockade winter of 1942, a German aircraft shell pierced the roof of the building and exploded in the main hall. The fragments severely damaged the mineral, and it seemed that it would never find a place in the museum’s exhibition. However, after many years of painstaking work by restoration artists, the stone was restored to its original form. Now the only reminders of that incident are two rusty fragments mounted in a plate of plexiglass, and an explanatory plaque telling about this exhibit.
Beryllium has a lot of unique qualities, one of which is its amazing “sound transmission” ability. As you know, in air the speed of sound is 340 meters per second, in water - 1,490 meters per second. In beryllium, the sound breaks all records, covering 12,500 meters in a second!
The name beryllium comes from the name of the mineral beryl (ancient Greek βήρυλλος, beryllos), in turn this name comes from the name of the city Belur (Velluru) in South India, near Madras. Since ancient times, rich deposits of emeralds (a type of beryl) have been known in India.
Historians write that the Roman emperor Nero loved to watch gladiators fight in the circus through a large green emerald crystal. And even when Rome, which he set on fire, was burning, he admired the raging fire, looking at it through his emerald, and the colors of the fire merged with the green color of the stone into dark, ominous tongues.
Story
Beryllium is rightly called the metal of the future, but its history goes back centuries. Minerals containing element number four have been known to man as precious stones for several thousand years - for a long time people have been searching for and developing deposits of aquamarines, emeralds and beryls. Some of them mined in the territory Ancient Egypt back in the 17th century BC. e. In the lifeless Nubian desert - in the rich emerald mines of Queen Cleopatra - slaves mined beautiful green crystals at the cost of their lives. Precious stones were delivered in caravans to the shores of the Red Sea, from where they ended up in the palaces of the rulers of Europe, the Middle and Far East - Byzantine emperors, Persian Shahs, Chinese Vanirs, Indian Rajas. The name beryl is found among Greek and Roman (beryll) ancient authors. The similarity between beryl and emerald was noted by Pliny the Elder in his “Natural History”: “Beryl, if you think about it, has the same nature as emerald (emerald), or at least very similar.” Even in Rus', far from Nubia, this precious stone was known - in Svyatoslav’s Izbornik, beryl was noted under the name “virulion”.
However, the metal hidden in precious stones, could not be discovered for a long time. This fact is not surprising - even to a modern scientist who is armed with the latest equipment, with the help of which he can apply any research method (from radiochemical to spectral analysis), beryllium is quite difficult to detect. The fact is that this metal, in many of its properties, resembles aluminum and its compounds, hiding in minerals behind them. Imagine the difficulties that early explorers faced in the 18th century! Many scientists have tried to analyze beryl, but no one has been able to discover the new metal it contains. Even seventy years after the discovery, the similarity between beryllium and aluminum caused many problems for D.I. Mendeleev himself - precisely because of its similarity with the thirteenth element, beryllium was considered a trivalent metal with an atomic mass of 13.5, therefore, its place in the table should be between carbon and nitrogen. However, this situation introduced obvious confusion into the natural change in the properties of elements and called into question the correctness periodic law. Dmitry Ivanovich, convinced that he was right, insisted that the atomic weight of beryllium was determined incorrectly, and that the element was not trivalent, but divalent, having magnesian properties. Reasoning this way, Mendeleev placed beryllium in the second group, assigning it an atomic weight of 9. It so happened that quite soon all the assumptions of the great Russian chemist were confirmed by his former opponents - the Swedish chemists Lare Friederik Nilsson and Otto Peterson, who had previously been firmly convinced of the trivalency of beryllium. Their careful research showed that the atomic weight of this element is 9.1. Thus, thanks to beryllium, the “troublemaker” in the Periodic Table, one of the most important chemical laws triumphed.
However, let us return to the fact of the discovery of this metal. The French crystallographer and mineralogist René Juste Haüy, comparing samples of greenish-blue beryl crystals from Limoges and green emerald crystals from Peru, noted the similarity of their hardness, density and appearance. Intrigued by this, he suggested that the French chemist Nicolas Louis Vauquelin analyze these minerals for chemical identity. The results of Vauquelin’s experiments were amazing - the chemist found that both minerals contained not only oxides of aluminum and silicon, as was known before, but also a new “earth”, which was very reminiscent of aluminum oxide, but, unlike it, reacted with carbonate ammonium and did not produce alum. Taking advantage of this difference, Vauquelin separated oxides of aluminum and an unknown element. On February 15, 1798, at a meeting of the French Academy of Sciences, Vauquelin made a sensational report that beryl and emerald contained a new “earth”, different in properties from alumina, or aluminum oxide. Open element Vauquelin suggested calling it “wisteria” because of the sweetish taste of its salts (in Greek “glycos” means sweet), however famous chemists Martin Heinrich Klaproth and Anders Ekeberg considered this name unfortunate, since yttrium salts also have a sweetish taste. In the works of these scientists, the “earth” discovered by Vauquelin is called beryl. However, in scientific XIX literature century, the new element is called "glycium", "wisterium" or "glucinium". In Russia until mid-19th centuries, the oxide of this element was called “sweet earth”, “sweet earth”, “sweet earth”, and the element itself was called wisterium, glycinite, glycium, sweet earth. Now this name is preserved only in France. It is interesting to note that the proposal to call element number four beryllium back in 1814 was made by Kharkov professor F.I. Giese.
In the form simple substance The element discovered by Vauquelin was first obtained by the German chemist Friedrich Wöhler in 1828 by reducing beryllium chloride with potassium. Independently, in the same year, beryllium metal was isolated by the same method by the French chemist Antoine Bussy. However, the resulting powdered beryllium contained a large number of impurities; only seven decades later the Frenchman P. Lebeau was able to obtain pure metal beryllium by electrolysis of molten salts.
Being in nature
Beryllium is a typically rare element, the average content of this metal in earth's crust(clark) according to various estimates ranges from 6∙10-4% to 2∙10-4%. Scientists explain this low abundance by beryllium’s ability to interact with high-energy protons and neutrons. This theory is confirmed by the fact that there is little beryllium in the atmosphere of the sun and stars, but in interstellar space, where conditions for nuclear reactions unfavorable, its quantity increases sharply. At the same time, beryllium is not a trace element, because it is part of the surface deposits of beryl in pegmatite rocks, which were the last to form in granite domes. This fact is confirmed by the findings in granite pegmatites (which, by the way, are found in all countries) of giant beryls - ranging from a meter to nine meters in length and weighing several tons. Most element number four in igneous rocks is associated with plagioclases, where beryllium replaces silicon. However, its highest concentrations are characteristic of some dark-colored minerals and muscovite (tens, less often hundreds of grams per ton). If in alkaline rocks beryllium is almost completely dissipated, then during the formation of acidic rocks rocks it can accumulate in post-magmatic products - pegmatites and pneumatolithic-hydrothermal bodies. In acidic pegmatite rocks, the formation of significant concentrations of beryllium is associated with the processes of albitization and muscovitization. In pegmatites, beryllium forms its own minerals, but part of it (about 10%) is found in isomorphic form in rock-forming and minor minerals (quartz, mica, microcline, albite). In alkaline pegmatites, beryllium is present in small quantities in the composition of rare minerals: chkalovite, eudidymite, analcime and leucophane, where it is part of the anionic group. Post-magmatic solutions remove beryllium from the magma in the form of fluorine-containing emanations and complex compounds in association with tungsten, tin, molybdenum and lithium.
There is no clear opinion about the number of beryllium’s own minerals, but it is precisely established that there are more than thirty of them, but only six of them are considered more or less common. The most important of them is beryl 3BeO Al2O3 6SiO2, which has many color varieties. For example, emerald contains about 2% chromium, which gives it green, A pink Vorobievite is caused by an admixture of manganese (II) compounds. Aquamarine owes its blue color to iron (II) impurities, and golden-yellow heliodor is colored by iron (III) ions. Other varieties of beryl are also known, differing in color (dark blue, pink, red, pale blue, colorless, etc.). In addition to beryl, industrially important beryllium minerals are phenacite 2BeO SiO2, bertrandite 4BeO 2SiO2 H2O, helvite (Mn,Fe,Zn)43S, chrysoberyl and danalite.
Beryllium content in sea water extremely low - 6∙10-7 mg/l. Beryllium oxides and hydroxides are almost insoluble in water, so it is found in groundwater mainly in the form of suspensions (often in complex compounds With organic substances) and only partially dissolved. For these reasons, the beryllium content in natural waters small - at trace level (0.01-0.07 µg/l). In acidic waters the beryllium content is higher, in alkaline waters it is lower. The increased content of fluorine and organic matter in water promotes the accumulation of beryllium, and the presence of calcium, on the contrary, prevents its accumulation.
World natural resources beryllium is estimated at more than 80 thousand tons (based on beryllium content), of which about 65% is concentrated in the USA, where the main beryllium raw material is bertrandite ore. From other countries largest reserves China, Russia and Kazakhstan possess beryllium. Moreover, in Soviet times, beryllium on the territory modern Russia more was mined - Malyshevskoye ( Sverdlovsk region), Zavitinskoye (Chita region), Ermakovskoye (Buryatia), Pogranichnoye (Primorsky Territory) fields. However, after the reduction of the military-industrial complex and the curtailment of programs for the construction of new nuclear power plants, beryllium production fell sharply, which is why development at the Malyshevskoye and Ermakovskoye deposits was stopped and significantly reduced at the Zavitimskoye deposit. Moreover most The mined beryllium is sold to foreign countries; the main consumers of this metal are Europe and Japan.
Application
Due to the fact that beryllium in its pure form was obtained only in the most late XIX century, for a long time it could not find a worthy application. Therefore, in various reference books and encyclopedias of the early 20th century it was said about beryllium: “ Practical Application does not have." In order for the unique properties of element number four to find their application, it took time - time for the development of the current level of technology. And if in the thirties of the XX century Soviet academician A.E. Fersman called beryllium the metal of the future, but now it can rightfully be called the metal of the present.
A huge amount of beryllium is consumed as an alloying additive to various alloys based on aluminum, nickel, magnesium, copper and other metals. This additive provides high hardness, good electrical conductivity thermal conductivity and strength of alloys, corrosion resistance of surfaces of products made from these alloys. The most famous and used in technology are beryllium bronzes (in the USA in the 80s, up to 80% of beryllium produced) - alloys of copper with beryllium. They are used to make many 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. One of the consumers of this alloy is the aviation industry - it is estimated that in a modern heavy aircraft over a thousand parts are made of beryllium bronze. Thanks to your elastic properties Beryllium bronze serves as an excellent spring material. Springs made of this material practically do not experience fatigue: they can withstand up to 20 million load cycles, while springs made of ordinary carbon steel fail after 800-850 cycles. In addition, beryllium bronzes do not spark when they hit metal or stone, for this reason they are used to make special tools used in explosive work - in mines, powder factories, oil depots. Beryllium additives also improve other alloys, for example, those based on magnesium and aluminum: very small amounts of beryllium (0.005% is enough) greatly reduce the losses of magnesium alloys from combustion and oxidation during melting and casting. No less interesting properties Also possess beryllides - intermetallic compounds of beryllium with tantalum, niobium, zirconium and other refractory metals. Such compounds have exceptional hardness and resistance to oxidation, they can work for more than ten hours at a temperature of 1,650 °C. It is considered promising to produce alloys of beryllium with lithium - they will be lighter than water.
It is possible to increase the rigidity, strength and heat resistance of other metals without introducing beryllium into the alloy. In such cases, beryllization is used - saturation of the surface of a steel part with beryllium by diffusion. After which the surface of the part is coated with a solid chemical compound of beryllium with iron and carbon. This durable protective coating with a thickness of only 0.15...0.4 mm gives the parts heat resistance and resistance to sea water and nitric acid.
Combination of small atomic mass, small cross section for thermal neutron capture (0.009 barn per atom), large cross section for their dispersion and sufficient resistance under radiation conditions makes beryllium one of the best materials for the manufacture of neutron moderators and reflectors in nuclear reactors. The production of moderators and reflectors from beryllium and its oxide makes it possible to significantly reduce the core of reactors, increase the operating temperature and use nuclear fuel more efficiently. Windows are made from beryllium x-ray tubes, taking advantage of its high X-ray transmittance (17 times greater than aluminum). In mixtures with some α-radioactive nuclides (radium, polonium, actinium, plutonium), beryllium is used in ampoule neutron sources, since it has the property of intense neutron emission when bombarded by α-particles.
Beryllium and some of its compounds (in the form of a solution in liquid ammonia, in the form of beryllium hydride, a solution of beryllium borohydride in liquid ammonia) are considered as promising solid rocket fuel with the highest specific impulses. Beryllium compounds have found no less application than the metal itself: in laser technology, beryllium aluminate is used in the manufacture of solid-state emitters (rods, plates). Beryllium borohydride and fine beryllium powder impregnated with liquid oxygen or fluorine oxide are sometimes used as particularly powerful explosives(BB). Beryllium fluoride is used in nuclear technology for melting glass used to regulate small neutron fluxes. Beryllium oxide has many valuable properties - due to its high fire resistance (melting point 2,570 ° C), significant chemical resistance and high thermal conductivity, this material is used for lining induction furnaces and making crucibles for melting various metals and alloys. Beryllium oxide is the main material for the cladding of fuel elements (fuel rods) of nuclear reactors. After all, it is in these shells that the neutron flux density and the highest temperature, the highest stresses and all the conditions for corrosion are especially high. Since uranium is corrosion unstable and not strong enough, it has to be protected with special shells, usually made of beryllium oxide.
Production
Extracting beryllium from its natural minerals (mainly beryl) is a complex and expensive process consisting of several stages. Moreover, the main difficulty lies in separating element number four from its constant companion, aluminum, which is similar in properties. There are several methods for such separation. For example, one of the methods is that beryllium oxyacetate Be4O(CH3COO)6, unlike aluminum oxyacetate +CH3COO–, has a molecular structure and easily sublimes when heated. However, other methods for purifying beryllium from aluminum are used in industry.
The first, the sulfate separation method, consists of sintering the concentrate at a temperature of 750 °C with sodium carbonate Na2CO3 (soda) or calcium carbonate CaCO3 (chalk), followed by treating the cake with concentrated hot sulfuric acid H2SO4. From the resulting solution of beryllium, aluminum and other elements sulfates contained in the original ore concentrate, aluminum is separated in the form of aluminum-ammonium alum by the action of ammonium sulfate (NH4)2SO4, the remaining solution is treated with excess sodium hydroxide NaOH. As a result, a solution containing Na2 and sodium aluminates is formed. Subsequently, when this solution is boiled, beryllium hydroxide Be(OH)2 is precipitated as a result of the decomposition of hydroxoberyllate, and the aluminates remain in the solution. Beryllium hydroxide is purified from impurities by extraction with tributyl phosphate.
The sulfate method is also used to extract beryllium from another beryllium mineral, bertrandite. In this case, the sulfuric acid solution is extracted with kerosene containing diethylhexyl phosphoric acid. The organic fraction is treated with an aqueous solution of (NH4)2CO3, while hydroxides and hydroxycarbonates of iron and aluminum are precipitated, and beryllium remains in the solution in the form of (NH4)2, which, when the solution is heated to 95 °C, quantitatively decomposes, forming a precipitate 2BeCO3∙Be(OH )2. When the latter is calcined at 165 °C, beryllium hydroxide is obtained.
The second method for separating Be and Al is fluoride. The technology of this method is as follows: the concentrate (crushed beryl) is sintered (at a temperature of about 750 °C) with sodium hexafluorosilicate Na2SiF6:
Be3Al2(SiO3)6 + 12Na2SiF6 → 6Na2SiO3 + 2Na3AlF6 + 3Na2 + 12SiF4
As a result of fusion, cryolite Na3AlF6 is formed, a compound poorly soluble in water, as well as sodium fluoroberyllate Na2, which is soluble in water, which is then leached with water. From the resulting solution, Be(OH)2 is precipitated by the action of sodium hydroxide NaOH, and upon calcination, BeO is formed. Sometimes beryllium hydroxide is further purified by dissolving it in sulfuric acid in the presence of complexones and then precipitating it with ammonia. To the solution containing NaF remaining after the action of sodium hydroxide, Fe2(SO4)3 is added to utilize the latter, and Na3 is precipitated, which is also used for the decomposition of beryl, partially replacing Na2.
In addition to the above separation methods, this method of processing beryl is also known. The original mineral is first fused with potash K2CO3. In this case, beryllate K2BeO2 and potassium aluminate KAlO2 are formed:
Be3Al2(SiO3)6 + 10K2CO3 → 3K2BeO2 + 2KAlO2 + 6K2SiO3 + 10CO2
After leaching with water, the resulting solution is acidified with sulfuric acid. As a result, silicic acid precipitates. Potassium alum is then precipitated from the filtrate, after which only Be2+ ions remain in the solution of cations.
It is also known to open beryl by chlorination or the action of phosgene. Further processing is carried out to obtain BeF2 or BeCl2.
From BeO oxide or beryllium hydroxide Be(OH)2 obtained in one way or another, BeC12 chloride or BeF2 fluoride is obtained. Fluoride is reduced to metallic beryllium by magnesium at 925-1325° C:
BeF2 + Mg → MgF2 + Be
A melt of a mixture of BeC12 and NaCl is subjected to electrolysis at a temperature of 350° C. Previously, beryllium was obtained by electrolysis of a melt of barium fluoroberyllate Ba:
Ba → BaF2 + Be + F2
The metal obtained by one method or another is melted in a vacuum. Beryllium is purified to 99.98% purity by vacuum distillation; small quantities of plastic beryllium containing no more than 10-4% impurities are obtained by zone melting. Sometimes electrolytic refining is used for purification.
To obtain blanks and products from beryllium, powder metallurgy methods are mainly used (due to the difficulty of producing high-quality castings from this brittle metal). In this case, beryllium is crushed into powder in an inert environment and subjected to hot pressing in a vacuum at 1,140-1,180 °C. Pipes, rods and other profiles from beryllium are produced by extrusion at 800-1,050 °C (hot extrusion) or at 400-500 °C (warm extrusion). Beryllium sheets are produced by rolling hot-pressed blanks or extruded strips at 760-840 °C. Other types of processing are also used - forging, stamping, drawing.
Physical properties
Beryllium is a brittle, but at the same time very hard metal of light gray color with a metallic sheen. Beryllium has two crystalline modifications: α-beryllium (low-temperature modification) has a hexagonal close-packed Mg-type lattice (which leads to anisotropy of properties) with parameters a = 0.22866 nm, c = 0.35833 nm, z = 2; β-beryllium (high-temperature modification) has a cubic body-centered lattice of the Fe type with a parameter a = 0.25515 nm. The transition temperature from the α-modification to the β-modification is approximately 1,277 °C. The melting point of element number four (tmelting point) is 1,285 ° C, the boiling point (t boiling point) is 2470 ° C. Beryllium is one of the lightest elements, its density in the solid state is only 1.816 g/cm3, even such a light metal as aluminum (density 2 .7 g/cm3), almost one and a half times heavier than beryllium. Moreover, in liquid state The density of beryllium is even lower (at 1,287 °C the density is 1.690 g/cm3). Beryllium has the highest heat capacity of all metals - 1.80 kJ/(kg K) or 0.43 kcal/(kg °C), high thermal conductivity - 178 W/(m K) or 0.45 cal/(cm sec ° C) at a temperature of 50 °C, low electrical resistance - 3.6-4.5 μOhm cm at room temperature; coefficient of linear expansion of beryllium 10.3-131 (25-100 °C).
Like most other elements, many physical properties beryllium depend on the quality and structure of the metal and change noticeably with temperature. For example, even small amounts of foreign impurities greatly embrittlement beryllium. The mechanical properties of beryllium depend on the purity of the metal, grain size and texture, determined by the nature of processing. Beryllium is difficult to cut and requires the use of carbide tools. Compared to others lightweight materials Beryllium has a unique combination of physical and mechanical properties. It surpasses all other metals in specific strength and rigidity, maintaining these advantages up to temperatures of 500-600 °C. The longitudinal modulus of elasticity (Young's modulus) for beryllium is 300 N/m2 or 3.104 kgf/mm2 (4 times greater than that of aluminum, 2.5 times greater than the corresponding parameter of titanium, and a third higher than that of steel). The tensile strength of beryllium is 200-550 MN/m2 (20-55 kgf/mm2), elongation 0.2-2%. Pressure treatment leads to a certain reorientation of beryllium crystals, as a result of which anisotropy occurs, and a significant improvement in properties becomes possible. The tensile strength in the drawing direction reaches 400-800 MN/m2 (40-80 kgf/mm2), the yield strength is 250-600 MN/m2 (25-60 kgf/mm2), and the relative elongation is up to 4-12%. The mechanical properties in the direction perpendicular to the hood remain almost unchanged. As mentioned earlier, beryllium is a brittle metal - its impact strength is 10-50 kJ/m2 (0.1-0.5 kgf∙m/cm2). The transition temperature of beryllium from a brittle to a plastic state is 200-400 °C. The Brinell hardness for beryllium is 1,060-1,320 MPa. Beryllium has high nuclear characteristics- lowest efficiency among metals cross section capture of thermal neutrons and the highest cross-section for their scattering.
At a huge number advantages, beryllium still has several disadvantages. Firstly, this is the high cost of this metal, associated with the scarcity of raw materials and the complexity of its processing, and secondly, beryllium has very low cold brittleness. The impact strength of technical beryllium is below 5 J/cm2. And yet, the unique set of technical advantages of beryllium makes it an indispensable material in various fields.
Chemical properties
IN chemical compounds beryllium is divalent (outer electron layer configuration 2s2). According to their own chemical properties beryllium is largely similar to aluminum, which is in the third period and in the third group of the periodic system, that is, to the right and below beryllium. This phenomenon, called diagonal similarity, is also observed in some other elements, for example, boron is similar to silicon in many chemical properties. The similarity of the properties of beryllium and aluminum is explained almost same attitude charge of the cation to its radius for Be2+ and Al3+ ions. Element number four is typically amphoteric - has the properties of a metal and a non-metal, however metallic properties prevail. Compact metal beryllium is chemically little active at room temperature - it does not oxidize in air (up to a temperature of 600 ° C), does not interact with hot and cold water, as well as water vapor due to the formation on its surface protective film beryllium oxide BeO, which gives beryllium a matte color. However, when heated above 800 °C, it quickly oxidizes. Beryllium oxide BeO occurs in nature in the form of a rare mineral - bromellite. Beryllium easily dissolves in hydrochloric acid (HCl), dilute sulfuric acid (H2SO4), hydrofluoric acids, reacts weakly with concentrated sulfuric and dilute nitric acids when heated (HNO3) and does not react with concentrated nitric acid - in the latter case the acid passivates the metal. In aqueous solutions of alkalis, beryllium also dissolves with the release of hydrogen and the formation of hydroxoberyllates:
Be + 2NaOH + 2H2O → Na2 + H2
When carrying out a reaction with an alkali melt at 400-500 °C, dioxoberyllates are formed:
Be + 2NaOH → Na2BeO2 + H2
Beryllium metal quickly dissolves in an aqueous solution of ammonium bifluoride NH4HF2. This reaction is of technological importance for the production of anhydrous BeF2 and the purification of beryllium:
Be + 2NH4HF2 → (NH4)2 + H2
When beryllium reacts with nitrogen and ammonia at 500-900° C, Be3N2 nitride is obtained. At room temperature, beryllium reacts with fluorine, and when heated with other halogens (forming halides, such as BeHal2) and hydrogen sulfide. Of the beryllium halides, the most important are its fluoride (BeF2) and chloride (BeCl2), used in the process of processing beryllium ores. With carbon at 1,700-2,100 °C, beryllium forms Be2C carbide, with phosphorus above 750 °C - Be3P2 phosphide. In a vacuum above 700 °C, beryllium reduces KOH, at 270 °C - BaO, at 1075 °C - MgO, at 1,400 °C - TiO2 to the corresponding metals and at 270 °C - SiCl4 to Si. Beryllium practically does not react with hydrogen over the entire temperature range, however, beryllium hydride (BeH2) is obtained indirectly by reducing beryllium chloride with LiAlH4; this substance is stable up to 240 °C, then when heated it begins to release hydrogen. At high temperatures, element #4 reacts with most metals to form beryllides. In the liquid state, beryllium dissolves in many metals (Zn, Al, Fe, Co, Cu, Ni, etc.), with the exception of magnesium. Beryllium forms eutectic alloys with aluminum and silicon. Element number four forms solid solutions with only a few metals; it is most soluble in alloys with copper (2.75% by weight), chromium (1.7%), and nickel (2.7%). Solubility decreases greatly with decreasing temperature, as a result of which alloys containing beryllium are capable of precipitation hardening. The solubility of impurity elements in beryllium is extremely low.
Fine beryllium powder burns in vapors of sulfur, selenium, and tellurium. When ignited in atmospheric air, beryllium powder burns with a bright flame, forming oxide and nitride. Molten beryllium reacts with most oxides, nitrides, sulfides and carbides. The only suitable crucible material for melting beryllium is beryllium oxide.
Beryllium salts are highly hygroscopic and, with a few exceptions (phosphate, carbonate), are highly soluble in water; their aqueous solutions are acidic due to hydrolysis. A number of complex organoberyllium compounds are known; hydrolysis and oxidation of some of them occur explosively.
