What is bismuth. Native bismuth mineral, description

From this article you will learn about where this metal is used and what interesting features are inherent in it. In particular, whether he is radioactive, as ornithologists used it and what diseases are treated with bismuth-containing drugs.

Until recently, the only natural isotope of bismuth was considered stable, but in 2003 his radioactivity was proven. True, his half-life is a few dozen times more than the age of our universe. So in terms of radioactivity, the natural bismuth is completely safe for a person.

Due to the insoluability of bismuth compounds is considered an environmentally friendly substance. Moreover, during the accident of the oil production platform in the Gulf of Mexico, the ornithologists were fed by biscuits bismuth to the withdrawal of oil that fell into their body.

Bismuth applications

The main consumer of bismuth performs metallurgy. Steel and aluminum containing only a few hundredths of the percentage of BI are much easier to process on machines. Bismuth alloys with cadmium, lead, zinc and other metals allow substances with a melting point below 100 ° C. Such alloys are smelted for manufacture:

- fuse fuses, fuse valves;
- lead-free and low-melting soldiers;
- babbittes for bearings;
- details on replacing harmful to ambient lead, for example, loaded for fishing rods, valves of water systems, fractions for hunting cartridges;
- Caps for armor-piercing shells;
- lubricants and sealing gaskets for working in vacuum;
- thermometric fluids for thermometers;
- coolants for atomic reactors;
- material for fixing fractures in traumatology, for prosthetics in dentistry;
- Materials for modeling in the foundry production.

Particularly clean bismuth is on the manufacture of instruments for measuring magnetic fields, since its resistance varies almost linearly depending on the magnitude of the magnetic field.

It is impossible not to mention that exquisite jewelry made from beautiful crystals of pure bismuth.

Bismuth alloys with manganese, chrome, India or Europe are used to produce high-quality powerful and durable permanent magnets. Bismuth compounds are on obtaining magnetoelectric, high-temperature ferroelectric, thermoelectric, superconducting materials.
- BI oxide with small additives of other metals is used to manufacture electrochemical fuel cells that can work at 500-700 ° C.
- Compounds with Gallium, Iodom, Germany are in demand as detectors of ionizing radiation in devices for computed tomography, nuclear physics, geology.
- Alloys and compounds are widely used for the manufacture of energy-intensive, stable and reliable batteries. For example, in batteries for cosmic and military apparatus.
- Bismuth oxide and nitrate - catalysts in the production of polymers based on acrylic; Bismuth in the form of chips - catalyst for the manufacture of oxidizing agents for rocket fuel.
- used to obtain polonium-210; in oil refining; For the production of pigments, low-temperature enamels for ceramics; Nail polish.
- in medicine, bismuth compounds are part of drugs used for the treatment of gastrointestinal tract, oncological diseases; antiseptics, wound healing; Contrast substance for x-ray. The bismuth-containing drugs are one of the few funds effective against a bacterium causing peptic ulcer of the stomach.

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Bismuth (Latin Bismuthum, denotes Bi) - element with atomic number 83 and atomic weight 208,9804. It is an element of the main subgroup of the fifth group, the sixth period of the periodic system of chemical elements of Dmitry Ivanovich Mendeleev. In the free non-oxidized state bismuth is a silver-gray metal with a pinkish shade and a pronounced metal glitter. This metal is simultaneously pretty soft and at the same time of the fragile, quite severe (density of 9.8 g / cm3) and the slight oxide. Without having bastard and drig, bismuth is easily crushed into powder.

Natural bismuth has only one isotope - 209Bi. For a long time, he was considered the most severe of the stable isotopes existing in nature, but in 2003, during the experiments, scientists have proven that 209Bi α-radioactive with a half-life of 1.9 ± 0.2 ∙ 1019 years (which, however, about half a billion times More than the age of our planet). It turns out that all known isotopes of bismuth radioactive. In addition to 209Bi, three more dozen isotopes are known (at the moment 34), most of which have isomeric states. 207Bi is considered long-lived (half-life of 31.55 years), 208Bi (0.368 ∙ 106 years), 210mbi (3.04 ∙ 106 years) - one of the isomeric states. All other radioactive and short-lived: periods of their half-life do not exceed several days. Bismuth isotopes with mass numbers from 184 to 208 and from 215 to 218 were obtained by artificial way (the heaviest of Bismuth isotopes - 215Bi, and not 209Bi, as previously assumed), the rest - 210BI, 211BI, 212BI, 213BI and 214BI - are formed in nature , entering the chains of the radioactive decay of uranium-238 kernels, uranium-235 and thorium-232.

Bismuth was known for a long time (the first mention of it in the chemical literature refers to the XV century), only for a long time he was considered a variety of tin, lead or antimony. Idea of \u200b\u200bbismuth as an independent chemical element It was only in the XVIII century, after in 1739 by the German chemist I. Potom installed its chemical personality. As for the name of the eighty-third element, there are many versions of the most common of which is the following: the word bismuthum or bisemutum allegedly comes from the German phrase of Weisse Masse, which means "white mass". Actually, as "bismuth" element introduced into a chemical nomenclature in 1819 by the Swedish chemist J. Bentselius.

For the most part, the metallic bismuth is spent on the production of low-melting alloys containing, in addition, lead, tin, cadmium (Wood alloy, for example). Such alloys are used for the manufacture of cliches with wooden matrices, in dental prosthetics, in automatic fire extinguishing systems, the action of which is based on the melting of traffic jams from such alloys. Alloys containing bismuth are used as soldiers. Pure metal bismuth is used mainly in energy nuclear reactors as a coolant. Wide use in various fields found bismuth compounds - in glass wool and ceramics (especially Bi2O3), in the pharmaceutical industry (the same bismuth threefold is used to make many drugs from gastrointestinal diseases, as well as antiseptic and healing means), in the chemical industry ( as catalysts). Bismuth oxide in graphite mixture is used as a positive electrode in bismouto magnesium elements (chemical current). Also as a positive electrode in lithium elements is the use of bismuth lead. In the textile industry, Vanadat bismuth is used as a pigment that gives the tissues bright yellow color.

Bismuth refers to toxic ultramic-elements. A little known about the physiological role of bismuth. Wismant induces the synthesis of low molecular weight proteins, takes part in the health processes, forms intracellular inclusions in the epithelium of the renal tubules. Perhaps this element has genotoxic and mutagenic properties. Inxication is usually observed only with prolonged exposure to the bismuth salts organism in large doses. Nevertheless, there are cases of non-heroed, professional and domestic poisoning.

Biological properties

The biological role of bismuth has been studied weakly, scientists suggest that this element induces the synthesis of low molecular weight proteins, takes part in the health processes, forms intracellular inclusions in the epithelium of the renal tubules. The current level of knowledge does not allow us to definitely talk about any physiological role of bismuth in the human body. There are only assumptions to which bismuth may also have genotoxic and mutagenic properties.

Arrival eighty-third element in the body with water or food is insignificant. The fact is that the suction of bismuth entered into the gastrointestinal tract is extremely small and is about 5%. A much more likely to receive bismuth in the body with drugs with medicinal drugs when taking them inside or through the skin (with external use). Total in the human body with food, as well as with air and water, bismuth flows in the amount of 5-20 μg / day. After suction, bismuth is found in the blood in the form of connections with proteins, and also penetrates erythrocytes. Between organs and tissues bismuth is distributed relatively evenly. Some bismuth accumulation can be observed in the liver, kidneys (up to 1 μg / g), spleen and bones. Bismuth is found in the brain.

Toxic and lethal doses of eighty-third element for humans are not defined. Dangerous is the chronic receipt of bismuth in quantities of 1-1.5 grams per day. This metal refers to the category of heavy, it is a moderately toxic element. A number of sources even calls bismuth "the most harmless" of all heavy metals. Being very close in its properties to the lead, bismuth is much less poisonous. In this regard, the environmentology is taking advantage of the gradual replacement of lead in industrial and production processes on bismuth. By the way, the widespread use of bismuth in metallurgy and electronics contributed to exactly the fact that bismuth is the least toxic of all heavy metals. Professional poisoning or skin diseases when working with bismuth is almost no not marked, the carcinogenicity of this metal is also not installed. Typically, even huge doses of bismuth, adopted orally do not cause poisoning, which is due to the difficulty of suction of bismuth compounds. However, sometimes, at exactly not established reasons, poisoning is observed and when receiving bismuth preparations orally. Scientists suggest that it is associated with an excess of lactic acid, which translates bismuth into a soluble connection and contributes to its suction. In white rats, when introduced into the stomach Bi2 (SO4) 3 or kbio3 (at 0.025-0.05 mg / kg for 6 months), there was a disruption of conditionaloreflex activity, and at 5 mg / kg - reduction of the content of free SH-groups in serum , liver, brain, reduction of liver succinate dehydrogenase activity, cholinesterase, alkaline phosphatase and alaninotransferase of blood. The poisonousness of the bismuth when introduced into the blood is high - about 1 mg per kg of live weight - and fluctuates depending on the speed of administration and from the type of experimental animal. The introduction of compounds of the eighty-third element under the skin also causes poisoning, but slower, and the dose for the toxic effect is much higher, especially when using insoluble compounds, only gradually resorbing. Bismuth poisoning can be sharp and chronic. The first is observed as when using bismuth on large fresh wound surfaces, as well as, when introduced into the blood of soluble bismuth compounds, not precipitating protein and therefore do not cause embolism.

Leukocytes are responsible for the transportation of bismuth to various organs in the body. Captured by leukocytes and separated by blood and lymphs throughout the body bismuth climbs in the spleen, the central nervous system and the selection organs, what are the kidneys, liver, intestines, salivary glands. Traces of this element were found in sweat, tears and breast milk. Bismuth, which passed through the gastrointestinal tract, is highlighted in the form of bismuth sulfide, staining cals in a dark color. Resorbed bismuth stands out with urine.

It is established that when poisoning bismuth salts, kidneys are affected, central nervous system, liver, leather and mucous membranes. In a person, after receiving a toxic dose, the symptoms of poisoning appear several days later: the pigmentation is found in the mouth, and a black border caused by the sedimation of sulfur bismuth appears on the gums. Then the stomatitis is developing, sometimes ulcerative, which can spread to the larynx and the esophagus. As a result, nausea appears, vomiting, gastralgy, meteorism, diarrhea, albuminuria. Next comes nutrition, eating and cachexia. Long-term reception of bismuth drugs in large doses can cause symptoms of "bismuth" encephalopathy (especially in patients with a violation of the kidney function). In the early stages of poisoning, take measures to stop the receipt of bismuth salts. To remove the non-Absorbed part of the bismuth, the stomach is washed and the laxatives are prescribed, the chelating therapy is carried out. With kidney lesions, hemodialysis is shown.

However, much more positive feedback causes bismuth compounds used in medicine. Bismuth forms connections with proteins, and its preparations have both astringent and antiseptic properties, which is based on the outer use of bismuth drugs in the treatment of burns and injuries. The same action (weakly astringent, limiting secretion and antiseptic) bismuth produces on the mucous membrane of the digestive tract. So, when entering the stomach, bismuth first climbs into the lower departments of this organ, and then it is distributed throughout its mucous membrane, forming as if protective cover, which is of particular importance in disruption of the intake of the mucous membrane (ulcers, erosion). Bismuth preparations have antibacterial effects (suppress Helicobacter Pylori growth). Bismuth compounds are used in inflammatory diseases of the stomach and intestines, the stomach and duodenal ulcer, diarrhea of \u200b\u200bvarious genesis, etc.

Bismuth compounds have an anticcompicure effect and the mechanism of their action is reduced to the fact that bismuth ions penetrating the spirochetes are associated with sulfhydryl groups (SN) of their enzymes. This leads to a violation of the life and death spirochet - syphilis pathogens. Such preparations are introduced intramuscularly, since when taking inside the compounds containing bismuth are practically not absorbed from the digestive tract. True, with such a bismuth receipt, there is a danger of defeating those organs in which bismuth ions accumulate. In addition, long-term (2 years) The use of bismuth preparations with therapeutic goal can lead to skin staining in gray.

Nitric acid bismuth BINO3 5H2O is usually obtained by evaporation of bismuth solution in nitric acid. In an aqueous solution, this salt is easily hydrolyzed and, when heated, the main bismuth nitrate (bio) is allocated (bio) NO3. This salt was known in the XVI century and was very popular with the handsaws of the Renaissance. It was used as a cosmetics, which was called Spanish Bellyl. What is interesting to bismuth-nitrate - this white powder, practically insoluble in water and alcohol, easily soluble in nitric acid, is prescribed inside with ulcer of the stomach and duodenal intestine, with inflammatory bowel diseases as a binder and antiseptic agent. The drug is effective and in external use (in ointments and powders) with inflammatory diseases of the skin and mucous membranes.

The first thermoelement battery, created about a century and a half ago, was made of spiped antimony and bismuth wires.

It is known that bismuth is relatively safe for ecology. This allows you to use a bismuth fraction instead of toxic lead.

In Russia, the bismuth containing deposits began to develop only during the First World War, when the need for medical and antiseptic equipment has sharply increased. Before this bismuth preparations were imported into tsarist Russia From Germany, but with the beginning of hostilities on the former commercial "companion", it was naturally not worth it. The Office of the Supreme Head of the Sanitary and Evacuation part appealed to the Academy of Sciences with a request to specify whether the ore of bismuth exists in Russia and is it possible to smell this metal from them. Vladimir Ivanovich Vernadsky was engaged in the decision of this issue, which in those years was headed by the Commission for the study of the natural productive forces of Russia. After examining the samples of the Mineralogical Museum of the Academy, the scientist concluded that search engine work should be conducted in Transbaikal, and one of his students KA soon went there. Radekvich - Future Corresponding Member of the USSR Academy of Sciences. Pretty Soon, non-idiophevich discovered a new mineral in the Sherlov mountain, named by Basobismutitis. The mineral turned out to be very rich in bismuth and could be an excellent raw material for its production. When conducting further research, the scientist discovered a number of bismuth fields, and already in 1918, from ores of one of them - Buckinsky - they were paid the first tens of kilograms of the domestic bismuth.

Bismuth is the strongest diamagnet, and the effect of diamagnetism on it can be observed in simple laboratory conditions (as opposed to other available, but very weak diamagnets). Sample bismuth suspended on the fine thread is noticeably repelled from any pole of a magnet. Having fairly large bismuth blocks and a powerful magnet, even at home can be seen that repulsion strength is enough to tear the magnet from the support. This is the so-called diamagnetic levitation.

History

A person's dating history with Bismuth is pretty old, but the man himself has never suspected that they found beautiful white nuggets with a slightly reddish tint - it is essentially elementary bismuth. People stubbornly mistaken, believing that only a variety of antimony, lead or tin hangs. So, in one of the alchemical dictionaries (the "Alchemical Dictionary" of Ruraland 1612), bismuth is described as "every lighter, pale and cheaper lead." The first information about metallic bismuth, its production and processing is found in the works of the largest metallurgist and mineral powder of Middle Ages George Agrikola dated mid-century. In his book "On the fields and mines in the old and new time", it equates bismuth to one of the main metals, adding it to a famous "magnificent seven" known from the antiquity - gold, silver, copper, gland, lead, tin and mercury. In addition to Agrikola, Vismut is mentioned in the works of many authors of the books of the XV - XVII centuries, in particular, Valentina and Paracelsa. From the same works of medieval alchemists, we will also learn about the truly huge number of names and titles, data bismuth. Lippman in his book "Geschichte des Wismuts Zwischen 1460 und 1800" (1930) leads twenty-one metal name, found in the literature of the XV - XVII centuries! Among such diversity there are very poetic and expressive names - demogorgon, glazor, nymph. Already known to us "Alchemical Dictionary" Ruiland speaks about white bismuth, as an analogue of Albedo (Albe Do - White), White Marcazite (under which, however, understood not the mineral FES2, but some metal ores), lead ash (plumbum cinereum) and other . A lot of disputes are being conducted on the origin of the word "bismuth", there are many versions. Some scientists (the same Lippman) believe that it is based on the German roots "WIS" and "MAT" (distorted Weisse Masse and Weisse Materia) - white metal (more precisely, white mass, white matter). Others are confident that the name happened from the German words "WIESE" (meadow) and "Muten" (to develop a mine), since this metal in the ancient times was mined in the meadows of Saxony, near Meisen. Third argument that the bismuth ores were rich in the district of a vissel in Germany - to him, they say, and is obliged to metal name. In any case, these three groups of scientists agree in one - the German origin of the name of the eighty-third element. Another thing is with the fourth group of historians who are confident that the word "bismuth" is nothing like the Arab Ismid, that is, "similar to antimony". It is difficult to give preference to some of these versions, for this reason, until now, scientists have not fully decided on the origin of the name of the eighty-third element. The same on bismuth as an independent chemical element developed only in the XVIII century, when Pott and Bergman set his differences from other metals and offered to consider bismuth with a simple body (1739). The current symbol of the number of eighty-three-Bi element is first introduced into the chemical nomenclature in 1819 by an outstanding Swedish chemist Jacob Yakov Burtsellius.

It is known that the bismuth compounds are widely used as paints, make-up, cosmetics. In Russia, for example, girls willingly used various Beliles, including bismuth, which were sometimes called Spanish. From the diary of one Englishman who visited the Russian state in the middle of the XVI century: "Women smear their faces so much that almost at the distance of the shot can be seen on the faces of paint; It is only better to compare them with the wives of Melnikov, because they look as if the flour bags were disappeared near them. " In Russian scientific literature Information about Bismuth is available in Lomonosov in its "first bases of metallurgy." In the "Chemical" Cadert Dictionary in 1810, bismuth and some of its compounds are described quite detailed and many synonyms of the name: Demogorgon (Demogorgon), Glaure (Glaure), Nymph (Nimphe), Glass (Fragile) Tin (Etain de Glace), Gray Tin (etain gris). IN early XIX. The century bismuth in Russia was sometimes called viszmouth and Bismuth.

Finding in nature

Bismuth is a very rare and rather scattered element. According to different estimates, the average content (Clark) of this element in the earth's crust is from 9 10-7% to 2 10-5% by weight, which means that a ton of substance earth crust There are only 0.2 grams of bismuth. According to the prevalence in the depths of our planet, element number 83 takes seventy first place! Its less than precious silver, less than many elements, firmly and long-enrolled in the category of rare and scattered, - Tallliament, India, Cadmium. Nevertheless, with a relatively small prevalence, bismuth shows a pronounced ability to form their own minerals in endogenous and hypergenic processes (about a hundred bismuth minerals). The pronounced bismuth ability to form its own minerals does not allow it to be attributed to the scattered elements in the generally accepted value of this word. In "Stranch", crystal lattices, as a rule, is not included. Exception is the lead mineral Galenite PBS, in whose lattice under certain conditions bismuth can be held without the formation of own minerals. The main minerals of the eighty-third element are considered - bismuth natives (contains 95.9-99.9% Bi), Bisimite Bi2O3 (89.7% Bi), bismutitis Bi2CO3 (OH) 4 (76.5-91.4% BI), bismutin or bismozer Bi2S3 bismuth (81.3% Bi), Tetradimit - Bi2Te2S (59.27% \u200b\u200bBi), televisionisomutitis Bi2Te3 (52% Bi), PB2Bi_S5 cozalit (42% Bi), CupBbis3 aquinite (36.3% BI). In a number of deposits, relatively rare minerals are acquired in bismuth ores: Berrit - (CU, AG) 3PB2Bi5S11 (51% Bi), Krukkit - CupBbBBI3S6 (57.4% BI), PAVONIT - (AG, CU) (BI, PB) 3S5 (62.5-66.7% BI) Wittihanit Cu3Bis3, Galenovutitis PBBI2S4 and others. Among bismuth ore deposits, endogenous and exogenous are distinguished. The main endogenous deposits of bismuth ores are postmagmatic, genetically connected with granitoid complexes. In exogenous conditions, with the destruction of indigenous deposits, small eluvial, deluel, less often deluel and alluvial placers arise. In the passing components of the actual bismuth ores are lead, copper, gold, silver, nickel and some other elements. The main industrial value is native bismuth, bismutin and sulfosol bismuth. However, the fields of its own bismuth ore are rare and relatively small in scale. In addition, it is difficult to call such a field, in which the concentration of the eighty-third element would be so high that it could be developed with the benefit only for the sake of bismuth. In the form of an exception, industrial accumulations of the native bismuth in the ore mountains (East Germany), Bolivia and Australia can be called. These mines belong to both the classical types of bismuth of native - low-temperature hydrothermal deposits are so-called five-element formations in which natives are associated with the arsenides of cobalt and nickel (Germany) - and to the Greessentian fields of tin and tolfram (Bolivia, Australia).

In addition to the actual bismuth ores, the bismuth-containing ores are isolated - ores of non-ferrous and noble metals, in which bismuth is passing or one of the components components. Bismuth-containing ores (0.001-0.1% Bi) of tungsten, tin, copper, gold and lead-zinc deposits are mainly a major, skarn, high-temperature hydrothermal groups. These are grasienne-tungsten deposits in Central Kazakhstan, Transbaikalia and a number of provinces of China; Skarnovo-Sheelite in Russia (Bogutinsky deposit, East-2) and South Korea (Sandon); Media in the USA (Montana, Utah, California); Skarn-polymetallic in Central Asia, Primorye (Dalnegora group of polymetallic deposits) and Mexico. These are tin-haul deposits in Bolivia (Tasna, Karakoles, Esmorak); Copper-gold in Australia (Tennant Creek district, Warrow, Juno and others); Copper and lead in Japan (southeast and north of Honshu Island); Polymetallic in Peru (CEPPO-de-Pasco). And yet it is impossible to argue that all these deposits are rich in bismuth, only the Bolivia deposits are the exception.

Application

Those times have long passed when Bismuth was considered "all siping, paral and cheaper lead", that is, a low-value metal with a limited application. Nowadays, this element is needed by each country with highly developed industry. Over the past decades, the demand and price for this metal have increased dramatically, which is not surprising, because to such traditional bismuth consumers as metallurgy, pharmaceuticals and the chemical industry were added electronics and nuclear power.

The main consumer of bismuth is metallurgy - obtaining low-melting alloys with lead, tin, cadmium; in the manufacture of forms for precise casting, stamps, milling, assembly and control devices; To improve the machinability of aluminum alloys, cast iron and steel in the production of aircraft and auto motories. The technique of bismuth has long been known for its low-fluid alloys, here's how the metallurgists of the beginning of the century respond about this metal: "In alloys, bismuth is used only because it gives them a slightweight. Thawed by this metal, tinkers and organicers enjoy when they need to have a particularly low-melting drug. The wrappers also add a bit of bismuth to facilitate the melting of the metal than, of course, do not improve their goods, because bismuth makes all the alloys brittle. " Nowadays, alloys containing bismuth are not used in typographic business, but there is a huge number of other areas where bismuth alloys have found their use. For example, flammable objects are equipped with automatic fire extinguishers with fuses from bismuth alloy with other metals. Alloys are more difficult, containing less bismuth, are used for safety valves in steam boilers - with a known pair temperature, such a valve melts and produces steam. Biscuit alloy with lead (1 part of the BI to 4 parts PB) extremely slightly floors and has the ability to firmly stick to solid objects, even to the glass, it is for this that this alloy is used for glass and metal spikes. The alloy of bismuth with lead and mercury melts already under friction and therefore used for the manufacture of metal pencils. Bismuth and manganese alloys (Mn) are characterized by ferromagnetic properties and therefore go to the manufacture of powerful permanent magnets. Bismuth alloy with antimony (88% Bi and 12% SB), manifesting in a magnetic field an unusual effect of magnetoresistance, is used to produce high-speed amplifiers and switches. The bismuth portion (only 0.01%) to aluminum and iron-based alloys improves the plastic properties of the material, simplifies its processing. The same effect has bismuth and stainless steel. The bismuth additive to the tin cures it from the "tin plague" - the bismuth atoms added to the tin, as if cementing his grille, not allowing it to collapse when restructuring. Many bismuth alloys at low temperatures acquire the property of superconductivity. High demand is used by bismuth compounds with tellurium used in thermoelectrogenerators. These compounds due to a successful combination of thermal conductivity, electrical conductivity and thermoelectric lifting force make it possible to transform thermal energy into electric with large efficiency (~ 7%).

The loss of bismuth has become one of the reasons for his arrival in nuclear power, where he works as a liquid coolant and cooling agent. Sometimes the uranium dissolved in the liquid bismuth is placed in the hot zone of the reactor. Of all the metals, only beryllium bismuth is inferior in the ability to dispel thermal neutrons, almost without absorbing them. The first method of extraction of plutonium from irradiated uranium was the method of deposition of plutonium with bismuth phosphate. Now this method is no longer used, however, it was based on modern methods for the release of plutonium by precipitation from acidic solutions. Using bismuth is obtained by isotope polonium-210, which serves as a source of energy on spacecraft.

Widespread use of the eighty-third element and compounds. Bismuth compounds, especially its trioxide Bi2O3, are used in the production of enamels, porcelain and glass - mainly as a flux that reduces the melting point of the mixture inorganic substancesFrom which enamel, porcelain or glass are formed. Bismuth compounds are introduced into glass, if you need to increase their refractive factor. In the production of polymers, bismuth trioxide serves as a catalyst; It is used, in particular, when producing acrylic polymers. Bismuth in the form of fine chips or powder is used as a catalyst for the production of tetraftorhydrazine (from nitrogen three-meter) used as an oxidizing agent of rocket fuel. With oil cracking, some application finds bismuth oxocloride. Three-spherical bismuth is used for the production of extremely energy-intensive (3000 watts / dm³, almost achieved - 1500-2300 W h b / dm³) Lanthan-fluoride batteries. However, among bismuth compounds with halogen, perhaps the greatest interest is BiCl3 three chloride. This is a white crystalline substance, has an unusual property: it darkens intensively in the light, but if it is placed after that in the darkness, it decolbles again. Three chloride bismuth is used to obtain waterproof bismuth resins and low-drying oils. Bismuth salts are used in the manufacture of paints for road signs that give glare when the automotive headlight is falling on them. For a long time, the cosmetic abilities of bismuth are manifested today in creating with its salts (bismuth oxochloride is used as a glossomy) of pearl lipstick, nail polish, shadows. In bismuth-based electronics produce semiconductors. Bismuth compounds for a long time are used by medicine: many medicines, powders and ointments, used as antiseptic and healing agents in the treatment of skin and gastrointestinal diseases, burns, wounds, contain in one or another bismuth. For no accident, the pharmaceutical industry is one of the main consumers of this metal.

Production

The accumulations of rich bismuth ores are extremely rare - the bismuth content in ores is usually the tenth or hundredths of the percent. In addition, they are limited in space and differ in non-uniformity distribution. Bismuth seems to be scattered in the ores of other elements. Therefore, it is difficult to find an ore field, in which there would be no eighty-third element, but it is even more difficult to detect such a field in which it would be so high that it could be developed only for the sake of bismuth. How is such a rare element? The answer is simple - bismuth take away from everywhere, where the extraction of its economically (or technologically) is justified. Source of element No. 83 serve lead, tin and other ores, where it is contained as an impurity. In the industrial production of bismuth, first from lead and copper ores (the bismuth content, in which the tenths usually represents, sometimes even hundredths of percent) are prepared concentrate. Of these concentrates, about 90% of the total bismuth is obtained.

The main source of the eighty-third element is lead concentrates obtained by processing lead, as well as lead-zinc and other polymetallic ores. These concentrates contain several hundred bills of bismuth, sometimes up to 0.2%, during their processing bismuth almost completely falls into the draft lead (camerts), from which it is removed during its fire refining. Typically, the discharge of bismuth from lead is produced by a pyrometallurgical method, which is based on bismuth ability to form refractory intermetallic compounds with potassium, sodium, magnesium and calcium. The melted lead add these metals and the solid compounds formed them with bismuth (throttle) are separated from the melt in the form of CAMG2BI2. A significant amount of bismuth is removed from the sludge of electrolytic refining lead in the siliconoftoric solution, as well as from dust and copper production sludge. Components of bismuth throtts and sludge to remove calcium and magnesium are interpretable under the layer of alkali with the addition of the oxidant (Nano3). Enriched alloy is usually subjected to electrolysis in a siliconfluoride bath with sludge, which further interpret on the draft bismuth. Sometimes the SL2 processing is used to separate lead. An electrolysis is also tested in low-melting saline melts with bismuth accumulation in the anode melt up to the production of rough bismuth. The obtained draft metal contains impurities as, Sb, Cu, Pb, Zn, SE, those, AG and some other elements.

In copper concentrates, the bismuth content is usually several thousandth percent, only occasionally - tenths. When they are recycling, bismuth concentrates in the dusties of melting furnaces and converters, from where it is removed by reducing melting with soda and coal. Copper bismuth concentrates with a comparable content of these elements are processed by hydrometallurgic. Leaching is performed at a temperature of about 105 ° C hydrochloric acid or H2SO4 with the addition of metal chlorides. Bismuth is isolated from hydrolytic precipitations (pH ~ 2.5) in the form of oxide or hydroxy chloride or iron reduction in the form of metal (cementation). To separate bismuth from the accompanying metals, extraction and ion exchange methods are used. Oxychloride precipitation is interpretable with the addition of soda and coal:

4BIOsl + 2NA2CO3 + 3C → 4BI + 4NACL + 5SO2

Bismuth gas supply from own ores is made on a small scale. Actually bismuth concentrates (usually contain no more than 3-5% bismuth by weight, in rare cases 30-60%) are obtained by enriching bismuth ores flotation and other methods. Recycled concentrates by reducing melting (after roasting or agglomeration) or precipitating smelting with the addition of metallic iron:

BI2S3 + 3FE → 2BI + 3FES

Known soda smelting:

4Bi2S3 + 12NA2CO3 → 8BI + 9NA2S + 3NA2SO4 + 12CO2,

as well as alkaline with NaOH. From oxidized ores, bismuth is restored by coal under the layer of the low-melting flux:

Bi2O3 + 3C → 2BI + 3CO

Depending on the composition of impurities in the draft bismuth extracted from concentrates, clean bismuth is obtained by various methods: oxidative refining under alkaline fluxes, zejejes, fusion with gray and others. Bismuth refining is the consistent processing of its melt: gray with the addition of coal (for removing iron and copper); alkali with the addition of oxidant or blowing air (to remove arsenic, antimony and tin); zinc (for removing gold and silver); chlorine (for lead and zinc removal). Electrolytic refining is also used as in aqueous solutions [BiSl3, Bi2 (SiF6) 3] and in salt melts. To produce high purity bismuth use a combination various methods. In addition, hydrolytic precipitation in the form of hydroxy salts is used to separate bismuth on the associated elements. Bismuth can also be besieged from solutions as well as Bipo4 ∙ H2O phosphate, oxycarbonate (BI) 2C3 0.5N2O, Bi (OH) CRO4 hydroxychromate and other connections. For the bismuth separation is also used by the deposition of chipoperon, thionalide, 8-hydroxy acid, extraction of amines from a hydrochloric acid solution. Commodity bismuth contains 99.9-99.98% of the main metal. High purity bismuth is obtained by zone recrystallization in quartz boats in an atmosphere of inert gas. The source of bismuth may be secondary raw materials. For example, in Germany, a significant amount of bismuth is removed in the processing of pyrite flats and from metal scrap.

The total production and production of bismuth was: in the 1930s of the 20th century - 600-700 tons, in 60s - 2600 tons, in 70s - 5380 tons and in our time - more than 10,000 tons. The main producers of bismuth are currently Bolivia, Peru, Mexico, Australia and the United States. In addition, the raw materials of bismuth are copper and lead-zinc ores of Japan, copper, lead and silver-cobalt deposits of Canada, tungsten fields of Russia.

Physical properties

Bismuth is a silver-gray metal with a pinkish tint, can exist in several crystalline modifications. In conventional atmospheric pressure, there is only one rhombohedral modification of bismuth with a coarserate structure and a spatial group R3M (lattice parameters with a period A \u003d 0.4746 nm (4,7364 E) and α-angle \u003d 57 ° 14 "13"). Rombohedral modification I At a pressure of 2.57 GPa and a temperature of 25 ° C passes into a modification II - a monoclinic spatial group C2M with lattice parameters: A \u003d 0.6674, B \u003d 0.6117; C \u003d 0.3304 and β-angle \u003d 110.33 °. At a pressure of 2.72 HPa, another phase transition occurs - III, then at 4.31 GPa - in IV, about 5 GPa - in V, at 7.74 GPa - in VI and then up to 30 GPa - in IX . In addition to changes in the modification, the pressure affects the melting point of bismuth - with an increase in pressure, the melting point of bismuth decreases, and in most metals it grows. This unusual property is considered to be due to the ability of bismuth to expand when hardening and compacted when melting. And it is not surprising: for all physical bodies is characteristic Certain correlation of changes, etc. descending under the action of temperature and pressure.

Bismuth is the last member of the main subgroup of the group of the periodic system, to which nitrogen, phosphorus, arsenic and antimony also belong. It is characterized by the predominance of metal properties over non-metallic and can be considered as a metal. In the form of a bismuth ingot possesses a plate addition, making it extremely brittle, without having a bagpit and drig, it easily splits on the planes of the scope and already at room temperature in the porcelain mortar in the powder. The rod made of metallic bismuth with a diameter of 2 mm bursts with a load of only 14 kilograms. At a temperature of 120-150 ° C, bismuth becomes damp, hot pressing (at 240-250 ° C) from it you can make a wire with a diameter of up to 0.1 mm, as well as a plate with a thickness of 0.2-0.3 mm. The hardness of the eighty-third element for brinell 93 MPa or 9.3 kgf / mm2, in MOO 2.5. Bismuth density in i modifications 9.80 g / cm3 - Web are definitely heavy metal. For comparison, the density of nickel is 8.9 g / cm3, iron - 7.87 g / cm3, chromium - 7.19 g / cm3. Low heavier bismuth molybdenum (10.2 g / cm3) and silver (10.5 g / cm3). The melting point of 271.4 ° C (bismuth is one of the most elbow metals), the boiling point of 1,564 ° C. What is interesting, the density of the liquid bismuth is higher - 10.27 g / cm3 (at a temperature of 271 ° C) than solid, that is, during melting, bismuth decreases in a volume by 3.27% (as ice). Melted bismuth breaks after pouring the glass tube, in which it was linged; The expansion does not begin to solidify. Scientists assume that the ability to be compacted during melting is explained by changing the type of communication between atoms. For a solid bismuth, covalently metallic communications are characterized by melting, covalent bonds are destroyed, and atoms remain connected with only metal connections. Heterogeneous (heterogeneous) nature of bonds in solid bismuth prevents the density packaging of atoms in the crystal lattice. Among other metals, the bismuth is distinguished by a low thermal conductivity - at 20 ° C. equal to 8.37 W / (M K) or 0.020 kal / (cm sec ° C) (worse than bismuth heat only cargo) and, if you can put it, the limit diamagneticity. If between the poles of the usual magnet, put the rod from bismuth, then he, pushing away from both poles, will settle just in the middle. The fact is that the bismuth crystals are characterized by a complex twin structure, which can only be seen under the microscope. The specific magnetic susceptibility of bismuth is -1.35 10-6. Under the influence of the magnetic field, the electrical resistance of bismuth increases to a greater extent than in other metals, which is used to measure the induction of strong magnetic fields.

The specific heat capacity of the eighty-third element at 20 ° C is 123.5 J / (kg to) or 0.0294 kal / (g ° C); Thermal linear extension coefficient at room temperature 13.3 10-6. The specific electrical resistance of the bismuth at a temperature of 20 ° C of 106.8 10-8 ohm m or 106.8 10-6 ohm cm. The cross section of the gripping of thermal neutrons in bismuth is small (34 10-31 m2 or 0.034 barn). Bismuth transition temperature in superconducting state ~ 7 K; Standard electrode potential 0.2 V.

Chemical properties

It is known that the main chemical properties any element is determined mainly by its location in periodic system And, consequently, the structure of its electronic shells, especially external. Among the elements of their group of the main subgroup (nitrogen, phosphorus, arsenic, antimony and bismuth), eighty-third element is the worst and most strongly expressed metal properties. As an element V of the Bismuth group exhibits valence +3 and +5 (and also -3, +1, +2, +4), but since it is closer to the metal properties, rather than any of its analogues, three electrons come off from its atom. More often and easier than five. In addition, only the connections of the trivalent bismuth (3+) are practically important, all natural connections of this element are also trivalent. The highest degree of oxidation +5 bismuth exhibits only in an alkaline medium under the action of strong oxidizers. Possessing atomic weight is somewhat large than lead, bismuth takes the place neighboring with him and is a great similarity by the properties of the compounds. Internal structure The bismuth atom is relative to him not only with arsenic and antimony, which is natural, but also with many other metals. In the bismuth atom, there is a penultimate 18-electron layer (a layer of type CU), which is characteristic of lead, as well as copper and its analogues (AU, AG).

In dry air bismuth is chemically stable, however, in a wet atmosphere, its surface oxidation is observed with the advent of a brown film. A noticeable oxidation begins at a temperature of about 500 ° C, and at temperatures above 1,000 ° C bismuth burns with a bluish flame with the formation of the main Bi2O3 oxide. In the nature of Bi2O3, it is possible to observe in the form of an earthy clusters of yellow and brown color - this is a mineral of bisamit or bismuth ocher. Bismuth (III) oxide can be obtained by calcining bismuth in air, as well as with the decomposition of bismuth nitrate Bi (NO3) 3 ∙ 5H2O. Bi2O3 has basic and easily dissolved in acids with the formation of bismuth salts (III), but practically dissolve in alkalis, even concentrated. When the chlorine is oxidized by the Bi2O3 suspension in the aqueous solution of Kohl at a temperature of about 100 ° C, an oxygen compound of the highest type is formed - bismuth anhydride - Bi2O5 - dark powder, decomposing when heated, as well as with a large ease of reducing agents. In addition, bismuth oxides BI2O, BI6O7 and BI8O11 are known. Bi2O5 does not dissolve in water, but is capable of forming the Bi2O5 ∙ H2O hydrate, or Biho3, the so-called bismuth acid, methydrate. The bismuth acid is obtained by passing chlorine through a boiling strong solution of caustic potassium, in which bismuth oxide is stirred in the form of a thin powder. The resulting liquid is first painted, then the red powder is deposited - the bismuth anhydride compound and potassium oxide. The powder is washed with boiling water, then a strong nitric acid, then more and weaker finally, again with water. Biho3 bismuth acid, dried at 100 ° C, represents a light red powder, losing at 130 ° C and turning into an anhydride, which at this temperature begins to decompose with the separation of oxygen. This hydrate to the grounds belongs as weak acid, weaker than antimony. Its salt with alkaline metals is easily decomposed with water and therefore are not very studied.

Bismuth does not react with hydrogen, carbon, nitrogen, silicon. Liquid bismuth slightly dissolves phosphorus. BIX3 bismuth halides are known, such as BIF3 pentafluoride, as well as the oxygaloids of biox compositions (x \u003d Cl, Br, I). When waving bismuth and sulfur, Bi2S3 composition sulphide is formed - crystalline substance grayAs a three-server antimony, like her, metal glitter. Bi2S3 has semiconductor and thermoelectric properties. When fusing bismuth with selenium (SE) or tellurium (TE), respectively, selenide or bismuth televaride are formed. Bismuth stands in a row of voltages between hydrogen and copper, therefore it does not dissolve in diluted sulfur and hydrochloric acids. The dissolution in concentrated sulfuric and nitric acids comes with the release of SO2 and the corresponding nitrogen oxides:

BI + 4HNO3 → BI (NO3) 3 + NO + 2H2O

2Bi + 6H2SO4 → BI2 (SO4) 3 + 3SO2 + 6H2O

As a result of the interaction of bismuth with nitric acid from the solution, bismuth nitrate Bi (NO3) 3 ∙ 5H2O is crystallized. It dissolves in a small amount of water, acidified with nitric acid. Under the action of acids on the bismuth alloy with magnesium (Mg), bismutin is formed, or bismuth hydride, Bih3 is a very unstable compound, decomposing already at room temperature. With most metals, when fusing bismuth, intermetallic compounds - bismuths, such as Na3BI, MG3BI and others. With aluminum melts, chromium and iron bismuth does not interact.

Bismuth (III) hydroxide, or bismuth hydroxide, Bi (OH) 3 is obtained as a white sediment under the action of alkalis for soluble bismuth salts:

Bi (NO3) 3 + 3NAOH → BI (OH) 3 ↓ + 3NanO3

Bismuth hydroxide is a very weak base. Therefore, bismuth (III) salts are easily subjected to hydrolysis, moving into the main salts, are not soluble in water.

The effect of very strong oxidizers on bismuth (III) compounds can be obtained bismuth (V) compounds. The most important of these are bismuths - salts of non-stable bismuth acid, for example, biscuitat potassium kbio3. These compounds are very strong oxidizing agents.

The native bismuth - the mineral of the native element class, which has a gray, pinkish or reddish color. In the Middle Ages, bismuth nuggets were often accepted for varieties of other minerals: native silver, tin, lead, antimony, etc. When interacting with water on the surface of the native bismuth, the so-called winning film is formed - oxide that gives a rideward coloration. The native bismuth is formed in the form of crystals with trigonal singonia. Crystals have a bright metal shine. Mineral is plastic, drig and damp.

It is often possible to hear that bismuth is isomorphic impurity in a number of metals. In part, this is a truthful statement, but this mineral is often found as an independent native metal. It is formed in natural processes and has a trigonal singonia.

History

Bismuth received its name in the XVI century and from that time he entered a number of famous chemical compositions. Even in the Middle Ages, the mineral was used for many alchemical experiments, as it was believed that he was almost half consistent with silver. After a while, this myth was dispelled. The Inca tribes were used as a material for the manufacture of cold weapons, especially the swords that had an original color due to the rainbow oxidation of the blade. About Bismuth as a metal for the first time they spoke in 1546 due to the works of minorologist Georgy Agrikola. But only in 1739, the mineral was allocated as an independent chemical element.

What does it look like?

Bismuth is a silver-white metal, which is why he was attributed to the similarity with silver. Frequently bismuth has a pinkish shade. Scientists know about eight forms and modifications of its crystallization, and most often there is a polymorphic, monoclinic and tetragonal metal grid. Bismuth has a metal gleam and is never transparent. You can identify it on a light gray or silver-white shiny feature. Differs nugget low level Hardness, due to which (not processed thermally) it can be easily cut.

Basic fields

You can find the deposits of the native bismuth on all continents of the planet. The largest deposits can be found in Russia, Germany (the so-called Ore Mountains and Saxagony of Sweden, Bolivia, Australia and many CIS countries. For industrial purposes, Bismuth is mined in Peru, Kornoral (United Kingdom), Dakota and California (USA).

The native bismuth deposits are known in the ore veins of the Western Ore Mountains (Germany).
Together with bismutin in large quantities, the native bismuth is found in Australia and Bolivia.
The findings of the native bismuth on the Sherlova Mount in Transbaikalia (Russia) are known.

Features of processing and use

Practical significance: Important bismuth ore. Bismuth is an indispensable element in many areas of production, especially in cosmetology and medical. Thus, oxide and bismuth chloride are used to make lipstick and varnishes, which gives these cosmetic products shine and color. The result is harmless to humans, which contributes to the continuous use of bismuth in cosmetology. In medicine, it is used as an antiseptic preparation. The metal concentrate is added to the drugs, which are discharged in inflammatory bowel diseases. Promotional attention is paid to bismuth as an instance from the collection of native minerals.

Usually in the native bismuth there are only minor traces of iron, sulfur, arsenic and antimony.

Crystals are rare and have a pseudo-cubic appearance. Skeletal crystals and dendrites are characterized, usually in the form of flattened grids, lattice or stalks. Units are dense, grainy, impression. The mineral is rough to the touch. It cuts the knife. Easily dissolved in NNO3.

Origin

Pneumatolitho-hydrothermal, often genetically connected to tin fiber deposits, characterized by associations with arsenopyrite, bismutin, topaz, beryl, tourmaline; Characterist to find a native bismuth in hydrothermal deposits of uranium arsenide type, where it associates with nickel minerals, cobalt, uranium.

Properties Mineral

Origin of name: Apparently, from the Arab Bi ISMID - the owner of the properties of antimony
Place of discovery: Schneeberg District, Erzgebirge, Saxony
Year of discovery: 1546
Thermal properties: Under p. Tr. Melts with an incredible ease, evaporated, and forms raids on the corner, - first white, and after cooling - lemon-yellow
IMA Status: valid
Typical impurities: FE, TE, AS, S, SB
Strunz (8th edition): 1 / B.01-40
Hey "S Cim Ref.: 1.49
Dana (7th edition): 1.3.1.5
Dana (8th edition): 1.3.1.4
Molecular weight: 208.98
Cell Parameters: A \u003d 4.55Å, C \u003d 11.85Å
Attitude: A: C \u003d 1: 2.604
The number of formula units (z): 6
Elementary cell volume: V 212.46 Å³.
Twin: Polysinthetic twinization usually
Point group: 3m (3 2 / m) - hexagonal-scalledhedral
Spatial group: R3M (R3 2 / M)
Density (calculated): 9.753
Density (measured): 9.7 - 9.83
Pleochroism: weak
A type: anisotropic
Optical anisotropy: Discernible
Color in reflected light: Brilliant creamy-white, passing into yellow
Selection form: Cubic crystals, dendrites (skeletal crystals)
Classes by systematics of the USSR: Metals
Classes IMA: Native elements
Chemical formula: BI
Singonia: trigonal
Color: Reddish, silver-white, usually with motley, green or red run
Color features: Light gray, silver white, shiny
Glitter: metal
Transparency: opaque
Cleavage: Perfect on (0001) perfect software (1011)
Fravel: uneven
Hardness: 2
Microhardness: VHN100 \u003d 16 - 18
Ductility: Yes
Literature: Dymkov Yu.M. Skeletal forms and dendritic textures. // In the book: Paragenesis of minerals of the Uranonous lived. M., Nedra, 1985, p. 62-70. Web Malinko S.V., Dubinchuk V.T., Nosoenko N.A. The native bismuth in the Dalnegore Borne Forest Rudes. Mineral. Well., 1990, 14, №1, p. 42-52 (essay geology, 1992, 6V213)

Photo Mineral

Articles on the topic

The origin of the name of Bismuth is unclear.
History of Bismuth (English. Bismuth, Franz. Bismuth, it. Wismut) is difficult, as right up to the XVIII century. This metal is confused with lead, tin and antimony.

Deposit Mineral Wismut

Kayiva
Kara-both
Kazakhstan
Russia

Among the elements of the periodic system bismuth - the latter is almost not a radioactive element. And he also opens the hornet of heavy elements - natural alpha emitters. Indeed, that bismuth, which we know chemical compounds, minerals and alloys, accepted (and not without reason) to be considered stable, and meanwhile, with subtle experiments it was established that the stability of bismuth is apparent. In reality, the kernel of its atoms is sometimes "dying", however, very infrequent: the half-life of the main natural isotope of bismuth 209 Bi is more than 2 · 10 18 years. It is about half a billion times more than the age of our planet ...

In addition to bismuth-209, another 19 isotopes of element number 83 are known. All of them are radioactive and short-lived: half-life periods do not exceed several days.

Thirteen bismuth isotopes with mass numbers from 197 to 208 and the heaviest 215 Bi was obtained by artificially, the remaining - 210 Bi, 211 Bi, 212 Bi, 213 Bi and 214 Bi are formed in nature as a result of the radioactive decay of uranium nuclei, thorium, actinium and Neptune.

Thus, despite the fact that in practice we meet only almost stable bismuth-209, we should not forget about the important role of the element number 83 in all areas of knowledge, one way or another associated with radioactivity. We will not, however, fall into another extreme. Practical importance acquired primarily stable (or more correctly - pseudoable) bismuth. Therefore, it is his main "hero" of further narration.

Why "bismuth"

Very long bismuth was not in hand. However, in his hands, it was undoubtedly kept in antiquity, and repeatedly. Only then did not understand that beautiful white nuggets with a slightly reddish tint - it is essentially elementary bismuth.

For a long time, this metal was considered a variety of antimony, lead or tin. The first information about metallic bismuth, its production and processing is found in the works of the largest metallurgist and mineralogne Middle Ages George Agrikola, dated 1529. The presentation of Bismuth as an independent chemical element was developed only in the XVIII century.

The origin of the name of this element is interpreted in different ways. Some researchers tend to consider it derived from the ancient Germanic word "Wismuth" (white metal), others - from the German words "WIESE" (meadow) and "Muten" (to develop a mine), because in Saxony, Bismuth since sincerprove was mined in the meadows of Circle Shneberg.

There is another version according to which the name of the element occurred from the Arab BIA IMMID, which means "owner of the properties of antimony." Bismuth really looks like it.

Which of these points of view is closest to the truth, it is difficult ... The current symbol of element No. 83, Bi is first introduced into the chemical nomenclature in 1819 by the Swedish Chemist Berzelius.

Bismuth - among metals

Unlike antimony, in bismuth metal properties clearly prevail over non-metallic. The fragile and pretty softly bonded, severely (density of 9.8 g / cm 3), slight oxide (melting point 271 ° C). It is characteristic of a strong metal shine and a white pinkish shade color. Among other metals, the bismuth is distinguished by a low thermal conductivity (it is worse than it only to mercury) and, if you can put it, the limit diamagneticity. If between the poles of the usual magnet, put the rod from bismuth, then he, pushing away from both poles, will settle just in the middle. For bismuth crystals, a complex twin structure is characterized, which can only be seen under the microscope.

The bismuth has another rare property: the hardening, it is significantly expanding in the volume (by 3.32% at 271 ° C). This property is used when you need to get very accurate and complex in the form of cast products.

It is assumed that the ability to compact when melting is explained by changing the type of communication between atoms. For a solid bismuth, covalently metallic communications are characterized by melting, covalent bonds are destroyed, and atoms remain connected with only metal connections. Heterogeneous (heterogeneous) nature of bonds in solid bismuth prevents the density packaging of atoms in the crystal lattice.

One unusual entails another. Pressure affects bismuth differently than on "normal" metals. With the growth of pressure, the melting point of bismuth decreases, and most of the metals grows. This unusual property is considered a consequence of bismuth ability to expand when hardening and compact when molting. And this is not surprising: for all physical bodies, a certain correlation of changes occurring under the action of temperature and pressure is characteristic.

Bismuth - Chemical Individuality

The main chemical properties of any element are defined, as is known, its position in the periodic system and, consequently, the structure of its electronic shells, especially external. Among the elements of the group V group, more precisely, its main subgroup (N, P, AS, SB, BI), bismuth is the hardest and "most metallic". As it should be the element V of the group, it exhibits 4+ and 5+ valence (as well as 3-, 1+, 2+, 4+), but because it is closer to the "pole of metal properties", than any of its analogues, three The electron is removed from its atom much more often and easier than five. Only compounds of the trivalent bismuth (3+) are practically important, and all natural connections of this element are also trivalent.

The inner structure of the BI atom is relative to it not only with arsenic and antimony, which is natural, but also with many other metals. In the bismuth atom, there is a penultimate 18-electron layer (a layer of type "Kupro"), which is characteristic of lead, as well as copper and its analogues (AU, AG). Interestingly, with the same elements bismuth is often connected in the ore deposits.

The ion radius of the trivalent bismuth (1.20 Å) differs little from the ion radius of silver (1.13 Å) and gold (1.37 Å).

In oxygenic acids, it is insoluble, only nitrogen and concentrated sulfuric acid. The bismuth atom has a rather large affinity for the electron (the redox potential of the Bi 3+ / Bi system is only +0.226 V), therefore, the Bi 3+ ion is relatively easily restored to the neutral atom. That is why in nature bismuth can often be found in native state, sometimes even in a concentration of practical interest.

At normal temperature in air, bismuth is stable and only slightly covered with a characteristic reddish concern, but at a temperature of red circulation, it is easily combusting, turning into Bi 2 O 3. This compound insoluble in water is easily dissolved in acids, but it is very difficult - in alkalis, even concentrated.

In Nature Bi 2 O 3, you can observe in the form of an earthly clusters of yellow and brown. This is Mineral Bismita. Together with another natural compound - bismuth carbonate, which was called Bismuth, it is considered the main oxygen-containing mineral bismuth.

But for geochemists, bismuth compounds with gray, selenium and tellurium are especially important. Among the bismuth minerals (and there are more than 70) more sulfides and television. Such minerals are of great practical importance. IN last years More confidently begin to talk about bismuth sulphides as typical complex compounds, and sometimes both inorganic polymers. In fact, one of the most common minerals of element No. 83, bismutinite, Bi 2 S 3, easy to imagine as a combination of ions + and -. In natural conditions, bismutinite is found in the form of well-grated silver crystals.

Bismuth - rare element

This statement may seem strange, especially after mentioning 70 minerals of element No. 83. Nevertheless, the bismuth content in the earth's crust is only 2 · 10 -5%; This means that on a ton of the substance of the earth's crust accounts for only 0.2 g of bismuth. Its less than precious silver, less than many elements, firmly and long-enrolled in the category of rare and scattered, - Tallliament, India, Cadmium.

Pay attention to the duality of bismuth behavior in nature. On the one hand, it can be concentrated in minerals, and on the other hand, it is possible to dissipate in ores (especially sulphide) so that its contents in them can be defined only in one word - "traces". The pronounced bismuth ability to form its own minerals does not allow it to be attributed to the scattered elements in the generally accepted value of this word. In "Stranch", crystal lattices, as a rule, is not included. Exception is the lead mineral Galenite PBS, in whose lattice under certain conditions bismuth can be held without the formation of own minerals.

Nevertheless, the accumulations of rich bismuth ores are very rare. They are extremely limited in space and differ in the uneven distribution, which, of course, delivers grieving geologists and miners engaged in the exploration and operation of bismuth deposits.

Bismuth minerals are hiding in the ores of other elements: tungsten, tin, copper, nickel, molybdenum, uranium, cobalt, arsenic, gold and other elements - different and unlike.

It is difficult to call the ore field, in which there would be no bismuth, but even more difficult to call such a field, in which it would be so high that it could be developed only for the sake of bismuth. How to be? They are simply coming: bismuth take away from everywhere, where the extraction of its economically (or technologically) is justified. Here is a list of bismuth raw sources that provide about 3/4 worlds (without the USSR) demand: copper, lead and silver mines, lead deposits Mexico, Copper and lead-zinc ores of Japan, Copper, lead and silver-cobalt deposits Canada, Wolframov- Tin and tin-silver ores of Bolivia.

Maybe all these sources are very rich in bismuth? No, with the exception of the Bolivian, all the listed ore bismuth is poor. The main producer of bismuth is the lead industry - extracts it from concentrates in which no more than hundredths, less than the tenth of the bismuth, and in the initial ores of polymetallic deposits from 0.0001 to 0.01% Bi. The same picture is also observed in the copper industry. Typically, bismuth is removed here from anodic sludges formed during electrolytic reaffining copper. The source of bismuth may be secondary raw materials. For example, in Germany, a significant amount of bismuth is removed when recycling pyrite flats and from metal scrap. How many bismuth get every year around the world? It is known that in 1968, world bismuth production (without the USSR) amounted to 3800 tons. It is assumed that the world need for Bismuth in 2000 will be 5 ... 6 thousand tons. What these thousands of tons go, the last chapter of our story.

Bismuth application

Traditional bismuth consumers are metallurgical, pharmaceutical and chemical industry. In recent decades, nuclear technique and electronics have been added to them.

To solder glass with metal, use low-melting alloys on a bismoge basis. Similar alloys (with cadmium, tin, lead) are used in automatic fire extinguishers. As soon as the ambient temperature reaches 70 ° C, a bismuth alloy stopper melts (49.41% Bi, 27.67% PB, 12.88% SN and 10.02% CD), and the fire extinguisher works automatically.

The loss of bismuth has become one of the reasons for his nuclear power. But there were others. Only beryllium (of all metals) is inferior to bismuth in the ability to dispel thermal neutrons, almost without absorbing them. Bismuth is used as a coolant and cooling agent in nuclear reactors. Sometimes the uranium dissolved in the liquid bismuth is placed in the hot zone of the reactor.

The very first method of extracting plutonium from irradiated uranium was the method of deposition of plutonium with bismuth phosphate. Together with Fluoride Lithium Lithium, this salt worked in the first industrial plants for the production of plutonium. The uranium irradiated with neutrons was dissolved in nitric acid, and then H 2 SO 4 was added to this solution. With uranium, it formed an insoluble complex, and the tetravalent plutonium remained in solution. From here he was besieged with Bipo 4, thereby separating from the mass of uranium. Now this method is no longer used, but it was worth mentioning at least because the experience gained by this method helped create more advanced and modern methods for the discharge of plutonium by precipitation from acidic solutions.

Using bismuth is obtained by isotope polonium-210, which serves as a source of energy on spacecraft.

The use of bismuth in metallurgy is also quite wide. In addition to the already mentioned alumina alloys and solders, bismuth (approximately 0.01%) are used in aluminum and iron-based alloys. This additive improves the plastic properties of the metal, simplifies its processing.

Some bismuth alloys have unique magnetic properties. Strong permanent magnets Make from alloy, the composition of which is determined by the MNBI formula. And the alloy of the composition 88% Bi and 12% SB in the magnetic field detects an abnormal effect of magnetoresistance; From this alloy manufactures high-speed amplifiers and switches.

Many bismuth alloys at low temperatures acquire the property of superconductivity.

Wide use of bismuth in metallurgy and electronics contributed to the fact that bismuth is the least toxic of all heavy metals.

From bismuth compounds, it is widely used by its trioxide Bi 2 O 3. In particular, it is used in the pharmaceutical industry for the manufacture of many drugs from gastrointestinal diseases, as well as antiseptic and healing means.

In the production of polymers, bismuth trioxide serves as a catalyst; It is used, in particular, when producing acrylic polymers. Bi 2 O 3 also use in the production of enamels, porcelain and glass - mainly as a flux that reduces the melting point of the mixture of inorganic substances, from which enamel, porcelain or glass are formed.

Bismuth salts are used in areas, very far from each other. This, for example, the production of pearl lipstick and the production of paints for road signs, which "light up" in the rays of automotive headlights ...

Far into the past was the time when Bismuth was considered a low-value metal with a limited scope. Now he needs all countries with highly developed industry. Therefore, the demand for it continues to grow. Not by chance over the past 40 years, the price of bismuth in the global market has grown six times.

First bismuth in Russia

"Captured by trust, mainly Germanic, bismuth is now a product, for which we are entirely dependent on Germany. Meanwhile, we have guidance on the possibility of finding its compounds, for example, in Transbaikalia. So wrote Vladimir Ivanovich Vernadsky in 1915 in his "note to the Commission on the study of the natural productive forces of Russia." He was right and very far from. It will take place only three years, and in 1918 another Russian scientist - K.A. Radekvich - will pay the first tens of kilograms of the domestic bismuth. Paying precisely from Transbaikal ores - from the sulfide concentrates of the tungsten field Bukuk.

Beauty of the Renaissance

Bismuth nitric acid Bino 3 · 5H 2 O is usually obtained by evaporation of bismuth solution in nitric acid. In an aqueous solution, this salt is easily hydrolyzed and, when heated, highlights the main bismuth nitrate (bismuth-nitrate) (BIO) NO 3. This salt was known in the XVI century. And he was very popular with the beauties of the Renaissance, it was used as a cosmetic agent, which was called Spanish Bellyl.

In the light - dark, in the dark - brighten

Among the bismuth compounds with halogens, it is perhaps the three chloride bismuth. This is a white crystalline substance that can be obtained in various ways, in particular the treatment of metallic bismuth tsarist vodka. BiCl 3 has an unusual property: he darkens intensively in the light, but if it is placed after that in the darkness, it decolbles again. In an aqueous solution, BiCl 3 is hydrolyzed with the formation of biocl chloride. Three chloride bismuth is used to obtain waterproof bismuth resins and low-drying oils.

origin of name

The origin of the name of the mineral is controversial. Maybe from the Arab "BI Ismid" - "owner of the properties of antimony" (Vernadsky).

English name Mineral Wismouth - Bismuth

Chemical composition

Usually in the native bismuth there are only marks of iron, sulfur, arsenic and antimony.

Crystallographic characteristic

Singonia bismuth native -Trigonal.

Class.Ditrigonal-scalledhedrical

Crystal structure

The structure of the type of arsenic, distances Bi - Bi 3.10 and 3,47 A.

Form stay in nature

Crystal appearance. Mineral crystals bismuth very rare; Rhombohedral, pseudocubic. Cubic. Dendriti (skeletal crystals).

Double software (1012), often polysinthetic; may occur when exposed to pressure.

Aggregates.In the form of individual grains, sometimes in large discharge (sheets, grainy), centers. Crystals are extremely rare.
In some fields, the weight of the solid secretions of the native bismuth reaches 22 kg.

Physical properties

Optical

Color. Reddish, silver-white, usually with motley, green or red party. In the fresh breakthrough, silver-white with a yellowish tint, a reddish beation appears over time.
The feature of the light gray, silver-white, shiny.
Glitter metal.
Singing - Run
Transparency. Opaque.

Mechanical

Hardness 2-2.5; Easily cutting.
The fragile, but with careful treatment with a hammer is sometimes flattened. On the planes (0001) gives a blowing figure with the location of the rays at an angle of 60 °
Density 9,78-9.83.
Spidity according to (0001) perfect, software (2021) is good; Separation of software (1012).
Fravel. grainy.

Chemical properties

Easily dissolved in HNO 3 after dilution drops a white precipitate; HCl dissolves harder. HNO 3 will deteriorate (slowly boils and boil), HCl (slowly raging), FECL 3 (booet, irritates, the structure is detected), HGCl 2 (rape).

Other properties

Diamagnetic. Melts at 271.3 °. The mineral is rough to the touch.

Artificial receipt of mineral

It turns out by electrolysis from solutions (usually imperfect crystals) and from melts (the best crystals).

Diagnostic signs

Similar minerals.Nickelin.

It is found out on a weak yellowish-reddish shade of running, strong metal gloss, perfect sphydrel, low hardness and relatively high density.
In polished sandings in the reflected light, it looks like a native silver, antimony, copper, gold, discrasit, almightonite, melonite. From these minerals is a smaller hardness. Copper, unlike the native bismuth, has a characteristic bright pink color. Decisive signs that are distinguished by native bismuth from silver, gold, etc., are: belonging to the 1st group on the relative relief in the sluff, distinct anisotropy, spheel, twin structure, fast darkening in air (the lack of motionlessness characteristic of silver).

Related minerals.Bismoge shine, arsenopyrite, tungsten, topaz, etc.

Origin and finding

Relatively rare mineral. Usually observed in small quantities. Deposited from hydrothermal solutions; It is found in pegmatites, skarn deposits, hydrothermal veins, sometimes in placers.

Change mineral

Oxidation products - Bisimite and Bismutitis, less often - bisomoclite.

Place of Birth

In pegmatites, large clusters are very rarely formed, associated with quartz, fields, tourmaline, beryl, fluorite, topaz, muscovite, lepidolite, and other pegmatite minerals (Emerald Copyright in Sverdlovsk region, Northern Karelia, Sherlova Mountain and Adun Chilon in Chita region; South Africa; Madagascar; Queensland in Australia, etc.).
It is observed in tungsten, molybdenum, tin-arsenic and lead-zinc ores dedicated to the scanners (Lyancanese-Molybdenum deposit in Uzbekistan and the Zeravshan-Gissar Mountain Area deposit in Tajikistan).
In high-temperature rolling, tungsten and molybdenum residential fields, native bismuth is observed together with cassiterite, tungsten, molybdenite, bismutin, chalcopyrite and other minerals (Akhatau, Kara-both and Aquaram in Kazakhstan; Sherlova Mountain, Beluha, Hanoror, Savondo, Oneon in the Chita region .; Wolframo-Molybdenum deposits of Hingano-Bureinsky district of the Amur region; Tin fields of the Kalbinsky ridge in Kazakhstan; Cornwell in England; Altenberg in Germany, etc.).
In the mid-temperature fields, native bismuth is observed together with arsenic and cobalt and nickel, as well as with silver and uranium minerals (Yakhimov in the Czech Republic; Shneberg, Annaberg, Johanngoregenstadt in Germany; Great Bear Lake and Cobalt in Canada; Akbulak in Kazakhstan; a number of deposits in the USA , Bolivia and other countries).
Occasionally, native bismuth is found in the zone of oxidation of sulfide deposits, it is possible like a neoplasm.
In some places, the pebbles of the native bismuth are encountered, often with the crusts of hypergenic products of its change (in Russia - in Western Siberia, Transbaikalia, as well as in Bolivia, Tasmania, etc.). The largest nuggets (up to 22 kg) were found in Tasmania's places.

Numerous ore veins of Western Ore Mountains: Schneberg, Annaberg, Yakhimov, etc.; In essential quantities, together with bismuth is found in Bolivia, Australia and in other places.

Practical use

Industrial clusters forms very rarely, is usually mined along the way with other bismuth minerals. Important bismuth ore.