Where is barium used? Barium sulfate for fluoroscopy - application, properties, instructions in medicine

Contents of the article

BARIUM– chemical element of group 2 periodic table, atomic number 56, relative atomic mass 137.33. Located in the sixth period between cesium and lanthanum. Natural barium consists of seven stable isotopes with mass numbers 130(0.101%), 132(0.097%), 134(2.42%), 135(6.59%), 136(7.81%), 137(11.32%) and 138(71 .66%). Barium in the majority chemical compounds shows maximum degree oxidation +2, but can also have zero. In nature, barium occurs only in the divalent state.

History of discovery.

In 1602, Casciarolo (Bolognese shoemaker and alchemist) picked up a stone in the surrounding mountains that was so heavy that Casciarolo suspected it was gold. Trying to isolate gold from a stone, the alchemist calcined it with coal. Although it was not possible to isolate gold, the experiment brought clearly encouraging results: the cooled calcination product glowed reddish in the dark. The news of such unusual find An unusual mineral, which received a number of names, created a real sensation in the alchemical environment - sun stone(Lapis solaris), Bologna stone (Lapis Boloniensis), Bolognese phosphorus (Phosphorum Boloniensis) became a participant in various experiments. But time passed, and gold did not even think of standing out, so interest in the new mineral gradually disappeared, and for a long time it was considered a modified form of gypsum or lime. Only a century and a half later, in 1774, the famous Swedish chemists Karl Scheele and Johan Hahn carefully studied the “Bologna stone” and established that it contained some kind of “heavy earth”. Later, in 1779, Guiton de Morveau named this "land" barote (barote) from Greek word“barue” - heavy, and later changed the name to barite (baryte). Under this name, barium earth appeared in chemistry textbooks of the late 18th and early 19th centuries. For example, in the textbook by A.L. Lavoisier (1789), barite is included in the list of salt-forming earthy substances simple bodies, and another name for barite is given - “heavy earth” (terre pesante, lat. terra ponderosa). The still unknown metal contained in the mineral began to be called barium (Latin - Barium). In Russian literature of the 19th century. the names barite and barium were also used. The next known barium mineral was natural barium carbonate, discovered in 1782 by Withering and later named witherite in his honor. Barium metal was first prepared by Englishman Humphry Davy in 1808 by electrolysis of wet barium hydroxide with a mercury cathode and subsequent evaporation of mercury from barium amalgam. It should be noted that in the same 1808, somewhat earlier than Davy, barium amalgam was obtained by the Swedish chemist Jens Berzelius. Despite its name, barium turned out to be a relatively light metal with a density of 3.78 g/cm 3, so in 1816 the English chemist Clark proposed rejecting the name “barium” on the grounds that if barium earth (barium oxide) is indeed heavier than other earths (oxides), then the metal, on the contrary, is lighter than other metals. Clark wanted to name this element plutonium in honor of the ancient Roman god, ruler of the underground kingdom of Pluto, but this proposal did not meet with support from other scientists and the light metal continued to be called “heavy.”

Barium in nature.

IN earth's crust contains 0.065% barium, it occurs in the form of sulfate, carbonate, silicates and aluminosilicates. The main barium minerals are the aforementioned barite (barium sulfate), also called heavy or Persian spar, and witherite (barium carbonate). The world's mineral resources of barite were estimated in 1999 at 2 billion tons, a significant part of them is concentrated in China (about 1 billion tons) and Kazakhstan (0.5 billion tons). There are large reserves of barite in the USA, India, Turkey, Morocco and Mexico. Russian barite resources are estimated at 10 million tons, its production is carried out at three main deposits located in Khakassia, Kemerovo and Chelyabinsk regions. The total annual production of barite in the world is about 7 million tons, Russia produces 5 thousand tons and imports 25 thousand tons of barite per year.

Receipt.

The main raw materials for the production of barium and its compounds are barite and, less commonly, witherite. Restoring these minerals coal, coke or natural gas, barium sulfide and oxide are obtained, respectively:

BaSO 4 + 4C = BaS + 4CO

BaSO 4 + 2CH 4 = BaS + 2C + 4H 2 O

BaCO 3 + C = BaO + 2CO

Barium metal is obtained by reducing it with aluminum oxide.

3BaO + 2Al = 3Ba + Al 2 O 3

This process was first carried out by the Russian physical chemist N.N. Beketov. This is how he described his experiments: “I took anhydrous barium oxide and, adding to it a certain amount of barium chloride, like flux, I put this mixture along with pieces of clay (aluminum) in a carbon crucible and heated it for several hours. After cooling the crucible, I found in it a metal alloy of a completely different type and physical properties, rather than clay. This alloy has a coarse-crystalline structure, is very brittle, a fresh fracture has a faint yellowish sheen; analysis showed that for 100 hours it consists of 33.3 barium and 66.7 clay or, otherwise, for one part of barium it contained two parts of clay...” Currently, the reduction process with aluminum is carried out in a vacuum at temperatures from 1100 to 1250 ° C, while the resulting barium evaporates and condenses on the cooler parts of the reactor.

In addition, barium can be obtained by electrolysis of a molten mixture of barium and calcium chlorides.

Simple substance.

Barium is a silvery-white malleable metal that shatters when struck sharply. Melting point 727° C, boiling point 1637° C, density 3.780 g/cm 3 . At normal pressure there are two allotropic modifications: up to 375° C, a -Ba with a cubic body-centered lattice is stable, above 375° C, b -Ba is stable. At high blood pressure a hexagonal modification is formed. Metal barium has high chemical activity; it oxidizes intensively in air, forming a film containing BaO, BaO 2 and Ba 3 N 2, and ignites with slight heating or impact.

2Ba + O 2 = 2BaO; Ba + O 2 = BaO 2; 3Ba + N 2 = Ba 3 N 2,

Therefore, barium is stored under a layer of kerosene or paraffin. Barium reacts vigorously with water and acid solutions, forming barium hydroxide or the corresponding salts:

Ba + 2H 2 O = Ba(OH) 2 + H 2

Ba + 2HCl = BaCl 2 + H 2

With halogens, barium forms halides, with hydrogen and nitrogen when heated - hydride and nitride, respectively.

Ba + Cl 2 = BaCl 2; Ba + H 2 = BaH 2

Metallic barium dissolves in liquid ammonia to form a dark blue solution, from which ammonia Ba(NH 3) 6 can be isolated - crystals with a golden luster that easily decompose with the release of ammonia. In this compound, barium has zero oxidation state.

Application in industry and science.

The use of barium metal is very limited due to its high chemical reactivity; barium compounds are used much more widely. An alloy of barium with aluminum - an Alba alloy containing 56% Ba - is the basis of getters (absorbers of residual gases in vacuum technology). To obtain the getter itself, barium is evaporated from the alloy by heating it in a evacuated flask of the device, as a result of which a “barium mirror” is formed on the cold parts of the flask. IN small quantities barium is used in metallurgy to purify molten copper and lead from impurities of sulfur, oxygen and nitrogen. Barium is added to printing and antifriction alloys; an alloy of barium and nickel is used to make parts for radio tubes and spark plug electrodes in carburetor engines. In addition, there are non-standard uses of barium. One of them is the creation of artificial comets: those released from spacecraft Barium vapor is easily ionized sun rays and turn into a bright plasma cloud. The first artificial comet was created in 1959 during the flight of a Soviet automatic interplanetary station"Luna-1". In the early 1970s, German and American physicists, conducting research electro magnetic field Earth, they released 15 kilograms of tiny barium powder over the territory of Colombia. The resulting plasma cloud stretched along the magnetic field lines, making it possible to clarify their position. In 1979, jets of barium particles were used to study the aurora.

Barium compounds.

Divalent barium compounds are of greatest practical interest.

Barium oxide(BaO): intermediate product in the production of barium - refractory (melting point about 2020° C) white powder, reacts with water to form barium hydroxide, absorbs carbon dioxide from the air, turning into carbonate:

BaO + H 2 O = Ba(OH) 2; BaO + CO 2 = BaCO 3

When calcined in air at a temperature of 500–600° C, barium oxide reacts with oxygen, forming peroxide, which, upon further heating to 700° C, again transforms into an oxide, eliminating oxygen:

2BaO + O 2 = 2BaO 2 ; 2BaO2 = 2BaO + O2

This is how oxygen was obtained until the end of the 19th century, until a method for releasing oxygen by distilling liquid air was developed.

In the laboratory, barium oxide can be prepared by calcining barium nitrate:

2Ba(NO3)2 = 2BaO + 4NO2 + O2

Now barium oxide is used as a water-removing agent, to obtain barium peroxide and to make ceramic magnets from barium ferrate (for this, a mixture of barium and iron oxide powders is sintered under a press in a strong magnetic field), but the main use of barium oxide is the manufacture of thermionic cathodes. In 1903, the young German scientist Wehnelt tested the law of the emission of electrons by solids, discovered shortly before by the English physicist Richardson. The first of the experiments with platinum wire completely confirmed the law, but control experiment failed: the flow of electrons sharply exceeded expected. Since the properties of the metal could not change, Wehnelt assumed that there was some kind of impurity on the surface of the platinum. After testing possible surface contaminants, he became convinced that the additional electrons were emitted by barium oxide, which was part of the lubricant of the vacuum pump used in the experiment. However scientific world did not immediately recognize this discovery, since his observation could not be reproduced. Only almost a quarter of a century later, the Englishman Kohler showed that in order to exhibit high thermionic emission, barium oxide must be heated at very high temperatures. low pressures oxygen. This phenomenon was only explained in 1935. German scientist Paul suggested that electrons are emitted by a small impurity of barium in the oxide: at low pressures, part of the oxygen evaporates from the oxide, and the remaining barium is easily ionized to form free electrons, which leave the crystal when heated:

2BaO = 2Ba + O 2 ; Ba = Ba 2+ + 2е

The correctness of this hypothesis was finally established in the late 1950s by Soviet chemists A. Bundel and P. Kovtun, who measured the concentration of barium impurity in the oxide and compared it with the flux of thermionic electron emission. Now barium oxide is the active part of most thermionic cathodes. For example, a beam of electrons that forms an image on a TV screen or computer monitor is emitted by barium oxide.

Barium hydroxide, octahydrate(Ba(OH)2· 8H2O). White powder, highly soluble in hot water(more than 50% at 80° C), worse in cold (3.7% at 20° C). The melting point of the octahydrate is 78° C; when heated to 130° C, it turns into anhydrous Ba(OH) 2. Barium hydroxide is produced by dissolving the oxide in hot water or by heating barium sulfide in a stream of superheated steam. Barium hydroxide easily reacts with carbon dioxide, so its aqueous solution, called “barite water,” is used in analytical chemistry as a reagent for CO 2. In addition, “barite water” serves as a reagent for sulfate and carbonate ions. Barium hydroxide is used to remove sulfate ions from plant and animal oils and industrial solutions, to obtain rubidium and cesium hydroxides, as a component of lubricants.

Barium carbonate(BaCO3). In nature, the mineral is witherite. White powder, insoluble in water, soluble in strong acids(except sulfur). When heated to 1000° C, it decomposes, releasing CO 2:

BaCO 3 = BaO + CO 2

Barium carbonate is added to glass to increase its refractive index and is added to enamels and glazes.

Barium sulfate(BaSO4). In nature - barite (heavy or Persian spar) - the main mineral of barium - is a white powder (melting point about 1680 ° C), practically insoluble in water (2.2 mg / l at 18 ° C), slowly dissolves in concentrated sulfuric acid.

The production of paints has long been associated with barium sulfate. True, at first its use was of a criminal nature: crushed barite was mixed with lead white, which significantly reduced the cost of the final product and, at the same time, deteriorated the quality of the paint. However, such modified whites were sold at the same price as regular whites, generating significant profits for dye plant owners. Back in 1859, the department of manufactures and domestic trade information was received about the fraudulent machinations of Yaroslavl manufacturers who added heavy spar to lead white, which “deceives consumers about the true quality of the product, and a request was also received to prohibit the said manufacturers from using spar in the production of lead white.” But these complaints came to nothing. Suffice it to say that in 1882 a spar plant was founded in Yaroslavl, which in 1885 produced 50 thousand pounds of crushed heavy spar. In the early 1890s, D.I. Mendeleev wrote: “...Barite is mixed into the mixture of white at many factories, since white brought from abroad contains this mixture to reduce the price.”

Barium sulfate is part of lithopone, a non-toxic white paint with high hiding power, widely in demand on the market. To make lithopone, aqueous solutions of barium sulfide and zinc sulfate are mixed, during which an exchange reaction occurs and a mixture of fine-crystalline barium sulfate and zinc sulfide - lithopone - precipitates, and pure water remains in the solution.

BaS + ZnSO 4 = BaSO 4 Ї + ZnSЇ

In the production of expensive grades of paper, barium sulfate plays the role of a filler and weighting agent, making the paper whiter and denser; it is also used as a filler for rubber and ceramics.

More than 95% of the barite mined in the world is used to prepare working solutions for drilling deep wells.

Barium sulfate strongly absorbs x-rays and gamma rays. This property is widely used in medicine for diagnosing gastrointestinal diseases. To do this, the patient is allowed to swallow a suspension of barium sulfate in water or its mixture with semolina porridge - “barium porridge” and then transilluminated x-rays. Those areas digestive tract, through which the “barium porridge” passes, look like dark spots in the picture. This way the doctor can get an idea of ​​the shape of the stomach and intestines and determine the location of the disease. Barium sulfate is also used to make barite concrete used in construction nuclear power plants and nuclear plants to protect against penetrating radiation.

Barium sulfide(BaS). Intermediate product in the production of barium and its compounds. The commercial product is a gray friable powder, poorly soluble in water. Barium sulfide is used to produce lithopone, in the leather industry to remove hairline from skins to obtain pure hydrogen sulfide. BaS is a component of many phosphors - substances that glow after absorbing light energy. This is what Casciarolo obtained by calcining barite with coal. By itself, barium sulfide does not glow: it requires the addition of activating substances - salts of bismuth, lead and other metals.

Barium titanate(BaTiO3). One of the most industrial important connections barium – white refractory (melting point 1616° C) crystalline substance, insoluble in water. Barium titanate is obtained by fusing titanium dioxide with barium carbonate at a temperature of about 1300° C:

BaCO 3 + TiO 2 = BaTiO 3 + CO 2

Barium titanate is one of the best ferroelectrics (), very valuable electrical materials. In 1944, Soviet physicist B.M. Vul discovered extraordinary ferroelectric abilities (very high dielectric constant) in barium titanate, which retained them in a wide temperature range - from almost absolute zero to +125 ° C. This circumstance, as well as the great mechanical strength and moisture resistance of barium titanate, contributed to the fact that it became one of the most important ferroelectrics used, for example , for manufacturing electrical capacitors. Barium titanate, like all ferroelectrics, also has piezoelectric properties: it changes its electrical characteristics under pressure. When exposed to an alternating electric field, oscillations occur in its crystals, and therefore they are used in piezoelements, radio circuits and automatic systems. Barium titanate was used in attempts to detect gravitational waves.

Other barium compounds.

Barium nitrate and chlorate (Ba(ClO 3) 2) – component fireworks, the addition of these compounds gives the flame a bright green color. Barium peroxide is a component of ignition mixtures for aluminothermy. Barium (Ba) tetracyanoplatinate(II) glows when exposed to X-rays and gamma rays. In 1895, the German physicist Wilhelm Roentgen, observing the glow of this substance, suggested the existence of a new radiation, later called X-rays. Now barium tetracyanoplatinate(II) is used to cover luminous instrument screens. Barium thiosulfate (BaS 2 O 3) gives colorless varnish a pearly tint, and by mixing it with glue, you can achieve a complete imitation of mother-of-pearl.

Toxicology of barium compounds.

All soluble barium salts are poisonous. Barium sulfate used in fluoroscopy is practically non-toxic. Lethal dose barium chloride is 0.8–0.9 g, barium carbonate is 2–4 g. When poisonous barium compounds are ingested, burning in the mouth, pain in the stomach, salivation, nausea, vomiting, dizziness, muscle weakness, shortness of breath, and slowness occur. heart rate and drop blood pressure. The main treatment for barium poisoning is gastric lavage and the use of laxatives.

The main sources of barium entering the human body are food (especially seafood) and drinking water. According to the recommendations of the World Health Organization, the barium content in drinking water should not exceed 0.7 mg/l; in Russia, much more stringent standards apply - 0.1 mg/l.

Yuri Krutyakov

DEFINITION

Barium- fifty-sixth element periodic table. Designation - Ba from the Latin "barium". Located in the sixth period, group IIA. Refers to metals. The nuclear charge is 56.

Barium occurs in nature mainly in the form of sulfates and carbonates, forming the minerals barite BaSO 4 and witherite BaCO 3 . The barium content in the earth's crust is 0.05% (mass), which is significantly less than the calcium content.

In the form simple substance barium is a silvery-white metal (Fig. 1), which in air is covered with a yellowish film of products of interaction with the components of air. Barium is similar in hardness to lead. Density 3.76 g/cm3. Melting point 727 o C, boiling point 1640 o C. It has a body-centered crystal lattice.

Rice. 1. Barium. Appearance.

Atomic and molecular mass of barium

DEFINITION

Relative molecular weight of the substance(M r) is a number showing how many times the mass of a given molecule is greater than 1/12 the mass of a carbon atom, and relative atomic mass of an element(A r) - how many times average weight atoms of a chemical element are more than 1/12 the mass of a carbon atom.

Since in the free state barium exists in the form of monatomic Ba molecules, the values ​​of its atomic and molecular weight match. They are equal to 137.327.

Barium isotopes

It is known that in nature barium can be found in the form of seven stable isotopes 130 Ba, 132 Ba, 134 Ba, 135 Ba, 136 Ba, 137 Ba and 138 Ba, of which 137 Ba is the most common (71.66%). Their mass numbers are 130, 132, 134, 135, 136, 137 and 138, respectively. The nucleus of an atom of the barium isotope 130 Ba contains fifty-six protons and seventy-four neutrons, and the remaining isotopes differ from it only in the number of neutrons.

There are artificial unstable isotopes barium with mass numbers from 114 to 153, as well as ten isomeric states of nuclei, among which the longest-lived isotope 133 Ba with a half-life of 10.51 years.

Barium ions

On the outside energy level The barium atom has two electrons, which are valence:

1s 2 2s 2 2p 6 3s 2 3p 6 3d 10 4s 2 4p 6 4d 10 5s 2 5p 6 6s 2 .

As a result chemical interaction barium gives its valence electrons, i.e. is their donor, and turns into a positively charged ion:

Ba 0 -2e → Ba 2+ .

Barium molecule and atom

In the free state, barium exists in the form of monoatomic Ba molecules. Here are some properties characterizing the barium atom and molecule:

Examples of problem solving

EXAMPLE 1

WITH chemical formula BaSO4. It is a white, odorless powder, insoluble in water. Its whiteness and opacity, as well as its high density, determine its main areas of application.

History of the name

Barium belongs to alkaline earth metals. The latter are so named because, according to D.I. Mendeleev, their compounds form an insoluble mass of earth, and the oxides “have an earthy appearance.” Barium is naturally found in the form of the mineral barite, which is barium sulfate with various impurities.

It was first discovered by Swedish chemists Scheele and Hahn in 1774 as part of the so-called heavy spar. This is where the name of the mineral came from (from the Greek “baris” - heavy), and then the metal itself, when in 1808 it was isolated in its pure form by Humphry Devi.

Physical properties

Since BaSO 4 is a salt of sulfuric acid, its physical properties are determined in part by the metal itself, which is soft, reactive and silvery-white. Natural barite is colorless (sometimes white) and transparent. Chemically pure BaSO 4 has a color from white to pale yellow, it is non-flammable, with a melting point of 1580°C.

What is the mass of barium sulfate? Molar mass its equal to 233.43 g/mol. It has an unusually high specific gravity - from 4.25 to 4.50 g/cm 3 . Given its insolubility in water, its high density makes it indispensable as a filler in aqueous drilling fluids.

Chemical properties

BaSO 4 is one of the most sparingly soluble compounds in water. It can be obtained from two highly soluble salts. Let's take an aqueous solution of sodium sulfate - Na 2 SO 4. Its molecule in water dissociates into three ions: two Na + and one SO 4 2-.

Na 2 SO 4 → 2Na + + SO 4 2-

Let us also take an aqueous solution of barium chloride - BaCl 2, the molecule of which dissociates into three ions: one Ba 2+ and two Cl -.

BaCl 2 → Ba 2+ + 2Cl -

Mix an aqueous solution of sulfate and a mixture containing chloride. Barium sulfate is formed as a result of the combination into one molecule of two ions with the same charge and opposite sign.

Ba 2+ + SO 4 2- → BaSO 4

Below you can see the complete equation for this reaction (the so-called molecular equation).

Na 2 SO 4 + BaCl 2 → 2NaCl + BaSO 4

As a result, an insoluble precipitate of barium sulfate is formed.

Commercial barite

In practice, the starting material for obtaining commercial barium sulfate, intended for use in drilling fluids when drilling oil and gas wells, is, as a rule, the mineral barite.

The term "primary" barite refers to commercial products, which include raw material (obtained from mines and quarries), as well as products of simple beneficiation by methods such as washing, precipitation, separation in heavy media, and flotation. Most raw barite requires bringing it to a minimum purity and density. The mineral used as a filler is crushed and sifted to a uniform size so that at least 97% of its particles are up to 75 microns in size, and no more than 30% are less than 6 microns. Primary barite must also be dense enough to specific gravity was 4.2 g/cm 3 or higher, but soft enough not to damage the bearings.

Obtaining a chemically pure product

Mineral barite is often contaminated with various impurities, mainly iron oxides, which color it various colors. It is processed carbothermically (heating with coke). The result is barium sulfide.

BaSO 4 + 4 C → BaS + 4 CO

The latter, unlike sulfate, is soluble in water and easily reacts with oxygen, halogens and acids.

BaS + H 2 SO 4 → BaSO 4 + H 2 S

To obtain a highly pure output product, sulfuric acid is used. The barium sulfate produced by this process is often called blancfix, which is French for “white fixed.” It is often found in consumer products, such as paints.

IN laboratory conditions Barium sulfate is formed by combining barium ions and sulfate ions in solution (see above). Since sulfate is the least toxic barium salt due to its insolubility, waste containing other barium salts is sometimes treated with sodium sulfate to bind all the barium, which is quite toxic.

From sulfate to hydroxide and back

Historically, barite was used to produce barium hydroxide Ba(OH) 2, necessary in sugar refining. This is generally a very interesting compound that is widely used in industry. It is highly soluble in water, forming a solution known as barite water. It is convenient to use for binding sulfate ions in various compositions by forming insoluble BaSO 4 .

We saw above that when heated in the presence of coke, it is easy to obtain water-soluble barium sulfide - BaS - from sulfate. The latter, when interacting with hot water forms hydroxide.

BaS + 2H 2 O → Ba(OH) 2 + H 2 S

Barium hydroxide and sodium sulfate, taken in solutions, when mixed, will give an insoluble precipitate of barium sulfate and sodium hydroxide.

Ba(OH) 2 + Na 2 SO 4 = BaSO 4 + 2NaOH

It turns out that natural barium sulfate (barite) industrially first turns into barium hydroxide, and then serves to produce the same sulfate when purifying various salt systems from sulfate ions. The reaction will proceed in exactly the same way when purifying a solution of copper sulfate from SO 4 2 ions. If you make a mixture of barium hydroxide + copper sulfate, the result will be copper hydroxide and insoluble barium sulfate.

CuSO 4 + Ba(OH) 2 → Cu(OH) 2 + BaSO 4 ↓

Even in a reaction with sulfuric acid itself, its sulfate ions will be completely bound with barium.

Use in drilling fluids

About 80% of the world's production of barium sulfate, purified and crushed barite, is consumed as a component of drilling fluids in the creation of oil and gas wells. Adding it increases the density of the fluid pumped into the well in order to better resist high reservoir pressure and prevent breakthroughs.

When a well is drilled, the bit passes through various educations, each of which has its own characteristics. The greater the depth, the greater the percentage of barite that should be present in the solution structure. An additional advantage is that barium sulfate is non-magnetic, so it does not interfere with conduction. various measurements in the well using electronic devices.

Paint and paper industry

Most synthetic BaSO 4 is used as a component of the white pigment for paints. Thus, blancfix mixed with titanium dioxide (TiO 2) is sold as a white oil paint used in painting.

The combination of BaSO 4 and ZnS (zinc sulfide) produces an inorganic pigment called lithopone. It is used as a coating for certain types of photographic paper.

More recently, barium sulfate has been used to brighten paper intended for inkjet printers.

Application in the chemical industry and non-ferrous metallurgy

In the production of polypropylene and polystyrene, BaSO 4 is used as a filler in a proportion of up to 70%. It has the effect of increasing the resistance of plastics to acids and alkalis and also imparting opacity to them.

It is also used to produce other barium compounds, particularly barium carbonate, which is used to make LED glass for television and computer screens (historically in cathode ray tubes).

Molds used in metal casting are often coated with barium sulfate to prevent adhesion to the molten metal. This is what is done in the manufacture of anode copper plates. They are cast into copper molds coated with a layer of barium sulfate. Once the liquid copper has solidified into a finished anode plate, it can be easily removed from the mold.

Pyrotechnic devices

Since barium compounds emit green light When burning, the salts of this substance are often used in pyrotechnic formulas. Although nitrate and chlorate are more common than sulfate, the latter is widely used as a component of pyrotechnic strobes.

X-ray contrast agent

Barium sulfate is a radiocontrast agent used to diagnose certain medical problems. Since such substances are opaque to x-rays (they block them as a result of their high density), then the areas of the body in which they are localized appear as white areas on x-ray film. This creates the necessary distinction between one (diagnosed) organ and other (surrounding) tissues. The contrast will help the doctor see any special conditions that may exist in that organ or body part.

Barium sulfate is taken by mouth or rectally with an enema. In the first case, it makes the esophagus, stomach or small intestine opaque to X-rays. This way they can be photographed. If the substance is administered through an enema, the colon or intestines can be seen and recorded with x-rays.

The dose of barium sulfate will be different for different patients, depending on the type of test. The drug is available in the form of a special medical barium suspension or in tablets. Various tests that require contrast and X-ray equipment require various quantities suspensions (in some cases it is necessary to take the drug in tablet form). Contrast material should only be used under the direct supervision of a physician.

Barium sulfate is active substance, which is used for diagnostic purposes for certain diseases of the digestive tract. It is a loose white powder, odorless and tasteless; it is insoluble in organic solvents, as well as in alkalis and acids. Let me look at the characteristics of this component. Let's talk about why barium sulfate is needed for fluoroscopy, we'll describe the medical use of this substance, we'll describe its properties, what the instructions say.

What is the effect of Barium sulfate?

Barium sulfate is a radiopaque substance; it is used for diagnostic purposes, as it improves the contrast of X-ray images when conducting relevant studies, and is non-toxic. Maximum radiopacity of organs such as the esophagus, stomach, and duodenum is achieved very quickly, immediately after its administration.

As for the small intestine, radiopacity occurs after about 15 minutes or an hour and a half, everything will depend on the viscosity of the drug and the speed of immediate gastric emptying. Maximum visualization of the distal parts of both the small and large intestines will depend on the patient's body position, as well as hydrostatic pressure.

Barium sulfate is not absorbed from the digestive tract, and therefore does not enter directly into the systemic circulation, of course, if there is no perforation of the gastrointestinal tract. This substance is excreted in the stool.

What are the indications for use of Barium sulfate?

A product is prescribed for radiography of the gastrointestinal tract, especially the small intestine, namely its upper sections.

What are the contraindications for use of Barium sulfate?

Among the contraindications to the use of Barium sulfate are the following conditions:

Having hypersensitivity to this substance;
It is not prescribed for colon obstruction;
In case of gastrointestinal perforation, the use of barium is contraindicated;
If you have a history of bronchial asthma;
When the body is dehydrated;
For acute ulcerative colitis;
For allergic reactions.

In addition to the above, this substance is not used if the patient has cystic fibrosis; acute diverticulitis is also considered a contraindication.

What are the side effects of Barium sulfate?

Among the side effects of Barium sulfate, the instructions for use note the following conditions: prolonged constipation may develop difficult character, spasms in some parts of the intestines are possible, and diarrhea may occur.

In addition, anaphylactoid reactions develop, which are manifested by difficulty breathing, painful bloating, chest tightness, pain in the stomach and intestines.

If after the first X-ray contrast study the patient developed any side effects, you should definitely inform your doctor about this.

What are the uses and dosage of Barium Sulfate?

To conduct a study of the upper digestive tract, a suspension of barium sulfate is taken orally; to conduct double contrast, sorbitol must be added, as well as sodium citrate. The so-called “barium gruel” in this case is prepared as follows: 80 g of powder is diluted in one hundred milliliters of water, after which a diagnostic procedure is performed.

For x-ray diagnostics of the colon, a suspension is prepared from 750 g of Barium sulfate powder and a liter of water, in addition, a 0.5% tannin solution is administered through an enema directly into the rectum.

On the eve of the diagnostic procedure, it is not recommended to eat solid food. After the study, you need to consume enough large number liquid, thereby speeding up the evacuation of barium sulfate from the intestines.

Special instructions

Preparations containing Barium sulfate (analogues)

The drug Bar-VIPS contains Barium sulfate; it is available in powder for the preparation of a diagnostic suspension for internal use. This radiocontrast agent has a complex composition and has low toxicity.

The next drug is Coribar-D, it is also produced in a paste, has pronounced adhesive properties, and provides a high-quality image of the relief of the mucous membrane of the digestive tract.

Micropack is his dosage form is also presented as a paste from which a suspension is prepared, and the drug is also produced in powder. The next product is Micropack Colon; when used, you can get a clear image of the microrelief.

Micropack Oral, Micropack ST, Microtrust esophagus paste, Co 2-granulate, Sulfobar, Falibarit, Falibarit HDE, as well as Adsobar, all of these listed radiocontrast drugs also contain the active substance Barium sulfate. They are produced both in the form of a paste, from which a suspension is prepared, and in the form of a fine powder.

X-ray contrast agents are used for diagnostic purposes to identify any pathology of the digestive tract, in particular the esophagus, stomach, and also all parts of the intestine. In addition, Barium sulfate is contained in the drug of the same name.

Conclusion

Before conducting an X-ray contrast study, the day before you must refrain from eating solid, long-digesting food. In this case, such a contrast examination should be prescribed by the attending doctor in accordance with the available indications.