Useful properties and uses of mercury. Mercury: interesting facts

All chemical elements of the periodic table are conventionally divided by the diagonal B - At into metals and non-metals. Moreover, the latter are in the minority and are located above and to the right of the border. Metals have a clear quantitative advantage; out of the known 118 elements, there are more than 80 of them.

They all have similar physical properties and are united by their state of aggregation. However, there is an exception - the element mercury. Let's talk about it in more detail.

Mercury: position in the periodic table

This element occupies its cell in the table at number 80. At the same time, it is located in the second group, a secondary subgroup, the sixth major period. It has an atomic mass of 200.59. Exists in the form of seven stable isotopes: 196, 198, 199, 200, 201, 202, 204.

It belongs to the elements of the d-family, but is not transitional, since the latter fill the s-orbital. Mercury is a member of the zinc metal subgroup, along with cadmium and copernicium.

General characteristics of the element

The chemical elements of the periodic table have a strictly ordered arrangement, and each has its own electronic configuration of the atom, which indicates its properties. Mercury is no exception. The structure of its outer and pre-outer electron shell is as follows: 5s 2 5p 6 5d 10 6s 2.

Possible oxidation states: +1, +2. Mercury oxide and hydroxide are weakly basic, sometimes amphoteric compounds. #80 - Hg, Latin pronunciation of "hydrargyrum". The Russian name comes from the Proto-Slavic language, in which it was translated as “roll.” Other peoples have different pronunciation and names. Often the element itself and the simple and complex substances it forms are called mercurates or mercury. This name comes from ancient times, when Hg (the element) was compared with silver, giving it second importance after gold. The Sun is the symbol of Aurum Au, Mercury is the symbol of Hydrargyrum Hg.

Ancient peoples believed that there were seven main metals, including mercury. A group of them was reflected in That is, gold was associated with the Sun, iron with Mars, mercury with Mercury, and so on.

History of discovery

Mercury has been known about for about 1,500 years. Even then it was described as “liquid silver,” a mobile, unusual and mysterious metal. They also learned how to extract it in ancient times.

Of course, it was not possible to study its properties, because chemistry as such had not yet been formed. Mercury was shrouded in a veil of mystery and magic; it was considered an unusual substance, close to silver and capable of turning into gold if made solid. However, there were no ways to obtain pure mercury in a solid state, and alchemical research was not successful.

The main countries where mercury has been used and mined since ancient times are:

China;
Mesopotamia;
India;
Egypt.

However, it was possible to obtain this metal in its pure form only in the 18th century, this was done by the Swedish chemist Brandt. At the same time, neither they nor until this moment provided evidence of the metallicity of the substance. This issue was clarified by M.V. Lomonosov and Brown. It was these scientists who were the first to freeze mercury and thus confirm that it has all the properties of metals - luster, electrical conductivity, malleability and plasticity, metallic

To date, a variety of mercury compounds have been obtained, and it is used in various areas of technical production.

Substance mercury

As a simple substance, it is a liquid (under normal conditions) silvery-white, mobile, and highly volatile. A typical example where liquid mercury in its pure form is used is to measure temperature.

If mercury is converted into a solid state, it will appear as translucent, odorless crystals. The vapors of this substance are colorless and very poisonous.

Physical properties

In terms of its physical properties, this metal is the only representative that, under normal conditions, is capable of existing in the form of a liquid. In all other properties, it fully matches the general characteristics of other representatives of the category.

The main properties are as follows.

Physical state: normal conditions - liquid, solid crystals - no higher than 352 o C, vapors - over 79 K.
Dissolves in benzene, dioxane, crystals in water. Has the ability not to wet glass.
Has diamagnetic properties.
Thermally conductive.

Melting of mercury occurs at a negative temperature of -38.83 o C. Therefore, this substance belongs to the group of explosives when heated. The internal energy reserve of the connection increases several times.

The boiling of mercury begins at a temperature of 356.73 o C. At this moment it begins to transition into a vapor state, which consists of molecules completely invisible to the eye, connected

The melting point of mercury shows that the properties of this metal are clearly unusual. This substance begins to evaporate, turning into invisible molecules of a gaseous state, already at ordinary room temperature, which makes it especially dangerous for human and animal health.

Chemical properties

The following groups of mercury-based compounds in different oxidation states are known:

sulfates, sulfides;
chlorides;
nitrates;
hydroxides;
oxides;
complex compounds;
organometallic substances;
intermetallic;
alloys with other metals - amalgams.

Mercury's melting point allows it to form both liquid and solid amalgams. In such alloys, metals lose their activity, becoming more inert.

The reaction between mercury and oxygen is possible only at a sufficiently high temperature, despite the strong oxidizing ability of the non-metal. Under conditions above 380 o C, as a result of this synthesis, a metal oxide is formed with the oxidation state of the latter +2.

The metal does not react chemically with acids, alkalis, and non-metals in its free form, remaining in a liquid state.

It reacts with halogens quite slowly and only in the cold, which is confirmed by the melting point of mercury. A good oxidizing agent for it is potassium permanganate.

Being in nature

Contained in the earth's crust, the oceans, ores and minerals. If we talk about the total percentage of mercury in the bowels of the earth, then this is approximately 0.000001%. In general, we can say that this element is diffuse. The main minerals and ores that contain this metal are as follows:

cinnabar;
quartz;
chalcedony;
mica;
carbonates;
lead-zinc ores.

In nature, mercury constantly circulates and takes part in the metabolic processes of all the layers of the Earth.

Obtaining mercury

The second method is based on the extraction of mercury also from sulfide using a strong reducing agent. Such as iron. The product is collected in the same way as in the previous case.

Biological effects on living organisms

The temperature of mercury needs to be low enough to go into a vapor state. This process begins already at 25 o C, that is, at ordinary room temperature. In this case, the presence of living organisms in the room becomes hazardous to health.

Thus, metal is able to penetrate into creatures through:

skin, intact, completely intact;
mucous membranes;
Airways;
digestive organs.

Once inside, mercury vapor enters the general bloodstream, and then enters into the synthesis of protein and other molecules, forming compounds with them. This is how harmful metal accumulates in the liver and bones. From places of storage, the metal can again be included in metabolic processes, syntheses and breakdowns, causing slow intoxication of the body, accompanied by the most severe consequences.

It is eliminated from organs quite slowly and under the influence of catalysts and adsorbents. For example, milk. The main liquids through which metal is released into the environment are:

saliva;
bile;
urine;
products of the gastrointestinal tract.

There are two main forms of poisoning with this substance: acute and chronic. Each has its own characteristics and manifestations.

Symptoms and treatment

The acute form is typical for cases when there is a mercury spill in production, that is, when a huge release of the substance into the atmosphere occurs simultaneously. In such situations, unprotected people begin to experience a sharp deterioration in their health, that is, poisoning. The symptoms are as follows:

The respiratory organs, lungs, and mucous membranes of the mouth and throat become inflamed.
Body temperature rises.
Ulcers form on the gums, they bleed, swell and become extremely sensitive. Sometimes a mercury rim forms.
Atrophy of the liver and kidneys is observed.
Chills, nausea and vomiting, dizziness.
The nervous system suffers greatly - speech and coordination of movements are impaired, and tremors of the limbs are observed.
Poisoning is accompanied by headaches and diarrhea with blood.

If the damage by mercury vapor occurs gradually, the disease will become chronic. In this case, the manifestations will not be so drastic, but the deterioration in well-being will accumulate daily, taking on ever larger proportions.

Tremor of the limbs.
Oral diseases (gingivitis, stomatitis and others).
Hypertension and tachycardia.
Sweating.
Nervous excitement.
Headache.
In severe cases, serious mental disorders, including schizophrenia, can be provoked.

All these consequences can occur due to even a slight release of mercury into the atmosphere. If you do not demercurize the premises in time, you can greatly harm your health.

Treatment in these cases is usually carried out with the following drugs:

vitamins;
antihistamines;
barbiturates;
"Aminazine."

Human use

The most common place for using and storing metallic mercury is in thermometers and thermometers. One such equipment can contain up to 3 g of metal. In addition, there are several other areas of human activity in which mercury is used quite widely:

medicine (calomel, mercuzal, promeran, many antiseptics);
technical activities - current sources, incandescent lamps, pumps, barometers, detonator, and so on;
metallurgy - deposition of mirrors, decoration with amalgams of gold and silver, production of metal alloys and pure substances;
chemical industry;
Agriculture.

Currently, due to the availability of safer and more convenient substances, mercury has been practically replaced from medicine.

Between the village of Karagash and the city of Slobodzeya, a local TV channel reported on Friday, citing the Ministry of State Security (MGB) of the unrecognized republic.

(Hg) - chemical element of group II of the periodic system of Mendeleev, atomic number 80, atomic mass 200.59; a silvery-white heavy metal, liquid at room temperature.

Mercury is one of the seven metals known since ancient times. Despite the fact that mercury is a trace element and there is very little of it in nature (about the same amount as silver), it is found in a free state in the form of inclusions in rocks.

In addition, it is very easy to isolate when roasting from the main mineral - sulfide (cinnabar). Mercury vapor easily condenses into a shiny, silver-like liquid. Its density is so high (13.6 g/cubic cm) that an ordinary person cannot even lift a bucket of mercury from the floor.

Mercury is widely used in the manufacture of scientific instruments (barometers, thermometers, pressure gauges, vacuum pumps, normal elements, polarographs, capillary electrometers, etc.), in mercury lamps, switches, rectifiers; as a liquid cathode in the production of caustic alkalis and chlorine by electrolysis, as a catalyst in the synthesis of acetic acid, in metallurgy for the amalgamation of gold and silver, in the manufacture of explosives; in medicine (calomel, mercuric chloride, organomercury and other compounds), as a pigment (cinnabar), in agriculture as a seed protectant and herbicide, and also as a component of the paint of sea ships (to combat fouling by their organisms).

At home, mercury can be found in a doorbell, fluorescent lamps, or a medical thermometer.

Metallic mercury is highly toxic to all life forms. The main danger is mercury vapor, the release of which from open surfaces increases with increasing air temperature. When inhaled, mercury enters the bloodstream. In the body, mercury circulates in the blood, combining with proteins; partially deposited in the liver, kidneys, spleen, brain tissue, etc.

The toxic effect is associated with blocking sulfhydryl groups of tissue proteins and disruption of brain activity (primarily the hypothalamus). Mercury is excreted from the body through the kidneys, intestines, sweat glands, etc.

Acute poisoning with mercury and its vapors is rare. In chronic poisoning, emotional instability, irritability, decreased performance, sleep disturbance, trembling of fingers, decreased sense of smell, and headaches are observed. A characteristic sign of poisoning is the appearance of a blue-black border along the edge of the gums; gum damage (looseness, bleeding) can lead to gingivitis and stomatitis.

In case of poisoning with organic mercury compounds (diethylmercury phosphate, diethylmercury, ethylmercury chloride), signs of simultaneous damage to the central nervous (encephalo-polyneuritis) and cardiovascular systems, stomach, liver, and kidneys predominate.

The main precaution when working with mercury and its compounds is to prevent mercury from entering the body through the respiratory tract or the surface of the skin.

Mercury spilled indoors must be collected most carefully. Especially a lot of vapor is formed if the mercury has scattered into many tiny droplets, which have clogged up in various cracks, for example, between parquet tiles. All these droplets need to be collected.

This is best done with tin foil, to which mercury easily sticks, or with copper wire washed with nitric acid. And those places where mercury could still linger are filled with a 20% solution of ferric chloride. A good preventive measure against mercury vapor poisoning is to thoroughly and regularly, for many weeks or even months, ventilate the area where the mercury was spilled.

The environmental consequences of infection with mercury vapor manifest themselves primarily in the aquatic environment - the vital activity of unicellular algae and fish is suppressed, photosynthesis is disrupted, nitrates, phosphates, ammonium compounds are assimilated, etc. Mercury vapor is phytotoxic and accelerates the aging of plants.

Mineral, natural metallic mercury. A transition metal, at room temperature it is a heavy, silvery-white liquid, the vapors of which are extremely toxic. Mercury is one of two chemical elements (and the only metal), the simple substances of which, under normal conditions, are in a liquid state of aggregation (the second such element is bromine). Sometimes it contains an admixture of silver and gold.

See also:

STRUCTURE

The system is trigonal, hexagonal-scalenohedral (below -39°C).

PROPERTIES

The color is pewter white. The shine is strong metallic. Boiling point 357 °C. The only liquid mineral at ordinary temperatures. It hardens, acquiring a crystalline state at −38°C. Density 13.55. Easily evaporates on fire to form toxic fumes. In ancient times, inhalation of these vapors was the only available means of treating syphilis (according to the principle: if the patient does not die, he will recover. It is diamagnetic.

RESERVES AND PRODUCTION

Mercury is a relatively rare element in the earth's crust with an average concentration of 83 mg/t. However, due to the fact that mercury weakly binds chemically to the most common elements in the earth's crust, mercury ores can be very concentrated compared to ordinary rocks. The most mercury-rich ores contain up to 2.5% mercury. The main form of mercury in nature is dispersed, and only 0.02% of it is contained in deposits. The mercury content in different types of igneous rocks is close to each other (about 100 mg/t). Among sedimentary rocks, the maximum concentrations of mercury are found in clay shales (up to 200 mg/t). In the waters of the World Ocean, the mercury content is 0.1 μg/l. The most important geochemical feature of mercury is that among other chalcophile elements it has the highest ionization potential. This determines such properties of mercury as the ability to be reduced to an atomic form (native mercury), significant chemical resistance to oxygen and acids.

One of the world's largest mercury deposits is located in Spain (Almaden). There are known deposits of mercury in the Caucasus (Dagestan, Armenia), Tajikistan, Slovenia, Kyrgyzstan (Khaidarkan - Aidarken) Ukraine (Gorlovka, Nikitovsky mercury plant).

There are 23 mercury deposits in Russia, industrial reserves amount to 15.6 thousand tons (as of 2002), of which the largest have been explored in Chukotka - West Palyanskoye and Tamvatneyskoye.

Mercury is obtained by roasting cinnabar (mercury(II) sulfide) or by the metallothermic method. Mercury vapor is condensed and collected. This method was used by ancient alchemists.

ORIGIN

Mercury is present in most sulfide minerals. Its especially high contents (up to thousandths and hundredths of a percent) are found in fahlores, stibnites, sphalerites and realgars. The proximity of the ionic radii of divalent mercury and calcium, monovalent mercury and barium determines their isomorphism in fluorites and barites. In cinnabar and metacinnabarite, sulfur is sometimes replaced by selenium or tellurium; The selenium content is often hundredths and tenths of a percent. Extremely rare mercury selenides are known - timanite (HgSe) and onofrite (a mixture of timanite and sphalerite).

APPLICATION

Mercury is used as a working fluid in mercury thermometers (especially high-precision ones), since it has a fairly wide range in which it is in the liquid state, its coefficient of thermal expansion is almost independent of temperature and has a relatively low heat capacity. An alloy of mercury and thallium is used for low-temperature thermometers.
Fluorescent lamps are filled with mercury vapor because the vapor glows in a glow discharge. The emission spectrum of mercury vapor contains a lot of ultraviolet light, and in order to convert it into visible light, the glass of fluorescent lamps is coated from the inside with a phosphor. Without a phosphor, mercury lamps are a source of hard ultraviolet light (254 nm), which is what they are used for. Such lamps are made of quartz glass, which transmits ultraviolet light, which is why they are called quartz.
Mercury and its alloys are used in sealed switches that turn on at a certain position.
Mercury is used in position sensors.

Mercury(I) iodide is used as a semiconductor radiation detector.
Mercury(II) fulminate (“mercury fulminate”) has long been used as an initiating explosive (Detonators).
Mercury(I) bromide is used in the thermochemical decomposition of water into hydrogen and oxygen (atomic hydrogen energy).
The use of mercury in alloys with cesium as a highly efficient working fluid in ion engines is promising.
Until the mid-20th century, mercury was widely used in barometers, pressure gauges and sphygmomanometers (hence the tradition of measuring pressure in millimeters of mercury).

Mercury compounds were used in the hat industry to make felt.

Mercury - Hg

CLASSIFICATION

Strunz (8th edition)	1/A.02-10
Nickel-Strunz (10th edition)	1.AD.05
Dana (7th edition)	1.1.10.1
Dana (8th edition)	1.1.7.1
Hey's CIM Ref	1.12

Mercury is an element of the secondary subgroup of the second group, the sixth period of the periodic system of chemical elements of D.I. Mendeleev, with atomic number 80. It is designated by the symbol Hg (lat. Hydrargyrum).

Mercury is one of two chemical elements (and the only metal), the simple substances of which, under normal conditions, are in a liquid state of aggregation (the second element is bromine). In nature, it is found both in native form and forms a number of minerals.

History of the discovery of mercury

Mercury (English Mercury, French Mercure, German Quecksilber) is one of the seven metals of antiquity. It was known at least 1500 BC; even then they knew how to obtain it from cinnabar. Mercury was used in Egypt, India, Mesopotamia and China; it was considered the most important raw material in the operations of the sacred secret art for the production of life-prolonging drugs called immortality pills. In the 4th - 3rd centuries. BC. Aristotle and Theophrastus mention mercury as liquid silver (from the Greek water and silver). Dioscorides later described the production of mercury from cinnabar by heating the latter with coal. Mercury was considered the basis of metals, close to gold, and therefore was called mercury (Mercurius), after the name of the planet Mercury closest to the sun (gold). On the other hand, believing that mercury was a certain state of silver, the ancient people called it liquid silver (from where the Latin Hydrargirum comes). The mobility of mercury gave rise to another name - living silver (lat. Argentum vivum); the German word Quecksilber comes from the Low Saxon Quick (live) and Silber (silver). It is interesting that the Bulgarian designation for mercury - zhivak - and the Azerbaijani one - jivya - were probably borrowed from the Slavs.

In Hellenistic Egypt and the Greeks, the name Scythian water was used, which allows us to think about the export of mercury at some period of time from Scythia. During the Arab period of the development of chemistry, the mercury-sulfur theory of the composition of metals arose, according to which mercury was revered as the mother of metals, and sulfur (sulfur) as their father. Many secret Arabic names for mercury have been preserved, indicating its importance in alchemical covert operations. The efforts of Arab and later Western European alchemists were reduced to the so-called fixation of mercury, that is, to transform it into a solid substance. According to alchemists, the resulting pure silver (philosophical) was easily transformed into gold. The legendary Vasily Valentine (XVI century) founded the theory of the three principles of alchemists (Tria principia) - mercury, sulfur and salt; this theory was later developed by Paracelsus. In the vast majority of alchemical treatises outlining methods of transmutation of metals, mercury comes first either as the starting metal for any operations, or as the basis of the philosopher's stone (philosopher's mercury).

Prevalence of mercury in nature

Natural sources such as volcanoes account for approximately half of all atmospheric mercury emissions. Human activity is responsible for the remaining half. The main share in it is made up of emissions from coal combustion mainly in thermal power plants - 65%, gold mining - 11%, smelting of non-ferrous metals - 6.8%, cement production - 6.4%, waste disposal - 3%, soda production - 3%, cast iron and steel - 1.4%, mercury (mainly for batteries) - 1.1%, the rest - 2%.

Mercury is a relatively rare element in the Earth's crust with an average concentration of 83 mg/t. However, due to the fact that mercury weakly binds chemically to the most common elements in the earth's crust, mercury ores can be very concentrated compared to ordinary rocks.

The most mercury-rich ores contain up to 2.5% mercury. The main form of mercury in nature is dispersed and only 0.02% of it is contained in deposits. The mercury content in different types of igneous rocks is close to each other (about 100 mg/t). Among sedimentary rocks, the maximum concentrations of mercury are found in clay shales (up to 200 mg/t). The mercury content in the waters of the World Ocean is 1 µg/l. The most important geochemical feature of mercury is that among other chalcophile elements it has the highest ionization potential. This determines such properties of mercury as the ability to be reduced to an atomic form (native mercury), significant chemical resistance to oxygen and acids.

There is evidence of the existence of a natural accumulation of mercury in the form of a small mercury lake.

Mercury is one of the most sensitive indicators of hidden mineralization not only of mercury, but also of various sulfide deposits, therefore mercury halos are usually detected above all hidden sulfide deposits and along pre-ore faults. This feature, as well as the low mercury content in rocks, is explained by the high elasticity of mercury vapor, which increases with temperature and determines the high migration of this element in the gas phase.

Under surface conditions, cinnabar and metallic mercury are soluble in water even in the absence of strong oxidizing agents, but in their presence (ozone, hydrogen peroxide), the solubility of these minerals reaches tens of mg/l. Mercury dissolves especially well in sulfides of caustic alkalis with the formation, for example, of the HgS nNa 2 S complex. Mercury is easily sorbed by clays, iron and manganese hydroxides, shales and coals.

About 20 mercury minerals are known in nature, but the main industrial value is cinnabar HgS (86.2% Hg). In rare cases, the subject of extraction is native mercury, metacinnabarite HgS and fahlore - schwatzite (up to 17% Hg). At the only Guitzuco deposit (Mexico), the main ore mineral is livingstonite HgSb 4 S 7. In the oxidation zone of mercury deposits, secondary mercury minerals are formed. These include, first of all, native mercury, less commonly metacinnabarite, which differ from the same primary minerals in greater purity of composition. Calomel Hg 2 Cl 2 is relatively common. Other supergene halide compounds are also common at the Terlingua deposit (Texas): terlinguaite Hg 2 ClO, eglestonite Hg 4 Cl.

Physical properties of mercury

It is the only metal that is liquid at room temperature. It has diamagnetic properties. Forms liquid alloys - amalgams - with many metals.

Mercury is 13.6 times heavier than water.

It has a fairly large coefficient of thermal expansion - only one and a half times less than that of water, and an order of magnitude, or even two, more than that of ordinary metals.

Chemical properties of mercury

Mercury is a low-active metal (see series of voltages).

When heated to 300 °C, mercury reacts with oxygen: 2Hg + O 2 → 2HgO Red mercury(II) oxide is formed. This reaction is reversible: when heated above 340 °C, the oxide decomposes to simple substances. The decomposition reaction of mercury oxide is historically one of the first ways to produce oxygen.

When mercury is heated with sulfur, mercury(II) sulfide is formed.

Mercury does not dissolve in solutions of acids that do not have oxidizing properties, but dissolves in aqua regia and nitric acid, forming divalent mercury salts. When excess mercury is dissolved in nitric acid in the cold, nitrate Hg 2 (NO 3) 2 is formed.

Of the elements of group IIB, it is mercury that has the possibility of destroying the very stable 6d 10 - electron shell, which leads to the possibility of the existence of mercury compounds (+4). So, in addition to the poorly soluble Hg 2 F 2 and HgF 2 decomposing with water, there is also HgF 4, obtained by the interaction of mercury atoms and a mixture of neon and fluorine at a temperature of 4 K.

Uses of mercury

Mercury is used in the manufacture of thermometers; mercury-quartz and fluorescent lamps are filled with mercury vapor. In them, mercury is used both in pure form and in the form of mixtures with gases (mainly argon) to increase light output. Mercury lamps are used as sources of intense UV radiation. Mercury contacts serve as position sensors. In addition, metallic mercury is used to produce a number of important alloys.

Previously, various metal amalgams, especially gold and silver amalgams, were widely used in jewelry, mirrors, and dental fillings. In technology, mercury was widely used for barometers and pressure gauges. Mercury compounds were used as an antiseptic (sublimate), laxative (calomel), in hat production, etc., but due to its high toxicity, by the end of the 20th century they were practically forced out of these areas (replacing amalgamation with sputtering and electrodeposition of metals, polymers fillings in dentistry).

Also, mercury is widely used in the production of thermometers. The melting point of mercury is –38 degrees, the boiling point is +356.58. But there are ways to push these boundaries and produce thermometers that work at both lower and higher temperatures. To lower the melting point, thallium is added to mercury.

Metallic mercury serves as a cathode for the electrolytic production of a number of active metals, chlorine and alkalis, in some chemical current sources (for example, mercury-zinc - type RC), in reference voltage sources (Weston element). The mercury-zinc element (emf 1.35 Volts) has very high energy in volume and mass (130 W/hour/kg, 550 W/hour/dm).

Mercury is sometimes alloyed with other metals. Small additions of the element increase the hardness of the lead alloy with alkaline earth metals. Even when soldering, mercury is sometimes needed: solder made of 93% lead, 3% tin and 4% mercury is the best material for soldering galvanized pipes.

Mercury is used in the processing of recycled aluminum and gold mining (see amalgam metallurgy).

One of the main parts of the fuse for an anti-aircraft projectile is a porous ring made of iron or nickel. The pores are filled with mercury. A shot is fired - the projectile has moved, it acquires increasing speed, rotates faster and faster around its axis, and heavy mercury protrudes from the pores. It closes the electrical circuit - an explosion.

Mercury is used as ballast in submarines and to control the roll and trim of some vehicles. The use of mercury in alloys with cesium as a highly efficient working fluid in ion engines is promising.

Previously, mercury paints were used to cover the bottoms of ships to prevent them from becoming overgrown with shells. Otherwise, the ship slows down and more fuel is consumed. The most famous of this type of paint is made on the basis of the acidic mercury salt of arsenic acid HgHAsO 4. True, recently synthetic dyes that do not contain mercury have been used for this purpose.

Mercury-203 (T 1/2 = 53 sec) is used in radiopharmacology. Medicine also uses phosphate salts of mercury, its sulfate, iodide and others. Nowadays, most inorganic mercury compounds are gradually being replaced from medicine by organic mercury compounds, which are incapable of easy ionization and therefore are not so toxic and less irritating to tissues.

Mercury salts are also used:

Mercury iodide is used as a semiconductor radiation detector.
Mercury fulminate (“Mercury fulminate”) has long been used as an initiating explosive (Detonators).
Mercury bromide is used in the thermochemical decomposition of water into hydrogen and oxygen (atomic hydrogen energy).

Some mercury compounds are used as medicines (for example, merthiolate for preserving vaccines), but mainly due to toxicity, mercury was forced out of medicine (sublimate, mercuric oxycyanide - antiseptics, calomel - laxative, etc.) in the mid-late 20th century.

Application of mercury compounds

Mercury amalgams

Another remarkable property of mercury: the ability to dissolve other metals, forming solid or liquid solutions - amalgams. Some of them, such as silver and cadmium amalgams, are chemically inert and hard at human body temperature, but soften easily when heated. They are used to make dental fillings.

Thallium amalgam, which hardens only at –60°C, is used in special designs of low-temperature thermometers.

Ancient mirrors were not coated with a thin layer of silver, as is done now, but with an amalgam, which included 70% tin and 30% mercury. In the past, amalgamation was the most important technological process in extracting gold from ores. In the 20th century, it could not withstand the competition and gave way to a more advanced process - cyanidation.

Some metals, in particular iron, cobalt, nickel, are practically not amenable to amalgamation. This makes it possible to transport liquid metal in containers made of plain steel. (Especially pure mercury is transported in containers made of glass, ceramics or plastic.) In addition to iron and its analogues, tantalum, silicon, rhenium, tungsten, vanadium, beryllium, titanium, manganese and molybdenum are not amalgamated, that is, almost all metals used for alloying become. This means that alloy steel is not afraid of mercury.

But sodium, for example, amalgamates very easily. Sodium amalgam is easily decomposed by water. These two circumstances have played and continue to play a very important role in the chlorine industry.

When producing chlorine and caustic soda by electrolysis of table salt, cathodes made of metallic mercury are used. To obtain a ton of caustic soda you need from 125 to 400 g of element No. 80. Today, the chlorine industry is one of the largest consumers of metallic mercury.

Cinnabar – red mercury

Cinnabar HgS. Thanks to her, man became acquainted with mercury many centuries ago. This was facilitated by its bright red color and the ease of obtaining mercury from cinnabar. Cinnabar crystals are sometimes coated with a thin lead-gray film. This is metacinnabarite, more about it below. However, it is enough to run a knife across the film and a bright red line will appear.

In nature, mercury sulfide occurs in three modifications, differing in crystal structure. In addition to the well-known cinnabar with a density of 8.18, there is also black metacinnabarite with a density of 7.7 and the so-called beta cinnabar (its density is 7.2). Russian craftsmen, when preparing red paint from cinnabar ore in the old days, paid special attention to removing “sparks” and “stars” from the ore. They did not know that these were allotropic changes of the same mercury sulphide; when heated without access to air to 386°C, these modifications turn into “real” cinnabar.

Some mercury compounds change color with temperature changes. These are red mercury oxide HgO and copper-mercury iodide HgI 2 · 2CuI.

Mercury toxicity

Mercury vapors, as well as metallic mercury, are very poisonous and can cause severe poisoning. Mercury and its compounds (sublimate, calomel, mercuric cyanide) affect the nervous system, liver, kidneys, gastrointestinal tract, and when inhaled, the respiratory tract (and the penetration of mercury into the body most often occurs when its odorless vapors are inhaled). According to the hazard class, mercury belongs to the first class (an extremely dangerous chemical substance). A dangerous environmental pollutant, releases into water are especially dangerous, since as a result of the activity of microorganisms inhabiting the bottom, water-soluble and toxic methylmercury is formed.

In some countries, calomel is used as a laxative. The toxic effect of calomel manifests itself especially when, after taking it orally, a laxative effect does not occur and the body is not freed from this drug for a long time.

Mercury(II) chloride, called sublimate, is very toxic. The toxicity of mercury(II) nitrate is approximately the same as the toxicity of mercuric chloride.

Maximum permissible levels of contamination with metallic mercury and its vapors:

MPC in populated areas (average daily) - 0.0003 mg/m³
MPC in residential premises (average daily) - 0.0003 mg/m³
Maximum permissible concentration of air in the working area (max. one-time) - 0.01 mg/m³
Maximum concentration of air in the working area (average shift) - 0.005 mg/m³
MPC of wastewater (for inorganic compounds in terms of divalent mercury) - 0.005 mg/ml
MPC of water bodies for domestic, drinking and cultural water use, in water of reservoirs - 0.0005 mg/l
MPC for fishery reservoirs - 0.00001 mg/l
MPC of marine reservoirs - 0.0001 mg/l
MPC in soil - 2.1 mg/kg

World mercury production

Mercury deposits are known in more than 40 countries around the world. World mercury resources are estimated at 715 thousand tons; quantitatively accounted reserves are 324 thousand tons, of which 26% are concentrated in Spain, 13% each in Kyrgyzstan and Russia, 8% in Ukraine, approximately 5-6.5% each - in Slovakia, Slovenia, China, Algeria, Morocco, Turkey. The supply of mercury reserves to the maximum level of its consumption, reached in the 1990s, is about 80 years for the world. Since the early 1970s. Due to environmental factors, the mercury market situation began to deteriorate noticeably. If in the early 1970s. world production of primary mercury (mining and smelting) was estimated at 10,000 tons per year, then by the end of the 1980s. it has more than doubled. This was accompanied by a decrease in mercury prices: from 11 -12 thousand US dollars per 1 ton in 1980-1982. up to 4-5 thousand dollars in 1994-1996.

Global mercury production in 2009 was already 3049 tons, and

identified mercury resources are estimated at 675 thousand tons (mainly in

Spain, Italy, Yugoslavia, Kyrgyzstan, Ukraine and Russia).

The largest producers of mercury are Spain (1497 tons), China (550 tons), Algeria

(290 t), Mexico (280 t), Kyrgyzstan (270 t), etc.

History of mercury production in Russia

The first information about the organization of mercury production in Russia dates back to 1725, according to which the merchant Pyotr Anisimov opened a mercury factory, and he kept the sources of raw materials secret. The mining of mercury ore (cinnabar) in Russia began in 1759 at the Ildikan deposit in Transbaikalia and continued in small quantities (periodically) until 1853. At the end of the 19th and beginning of the 20th centuries. cinnabar was extracted in small quantities from alluvial placers in the Amur region. Around the same time, separate sections of the mercury deposits of the Birksu ore field (Southern Fergana) and the Khpek deposit (Southern Dagestan) were being mined. In 1879, the Nikitovskoye mercury deposit (Donbass) was discovered, the exploitation of which (simultaneously with metal smelting) began in 1887. In 1887-1908. annual mercury production at the Nikitovsky mine varied between 47.3-615.9 tons). Calculations based on data show that from 1887 to 1917, 6,762 tons of metallic mercury were produced here, a significant part of which was exported (from 1889 to 1907, more than 5,145 tons of mercury were exported abroad). At the beginning of the twentieth century. Russia also imported cinnabar and mercury. For example, in 1913, 56 tons of cinnabar and 168 tons of mercury were imported into the country, in 1914 - 41 tons of cinnabar and 129 tons of mercury. In 1900-1908 mercury consumption in Russia ranged from 49-118 t/year. At this time, mercury was used in medicine and pharmaceuticals, in the manufacture of mirrors and paints, in the production of thermometers, barometers, pressure gauges and other instruments, it was used for rubbing the pads of electrical machines, extracting gold and silver using the amalgam method, gilding copper and bronze, cleaning felt, etc. gold embroidery and laboratory practice.

Periodic elements, zinc subgroup, atomic number – 80. In room conditions, the substance appears as a heavy white-silver liquid. Mercury vapor poisonous. Mercury temperature determines its state of aggregation; no other metal besides it has a liquid structure at room temperature.

Melting of mercury begins at a temperature of 234º K, boiling at 629º K. It fuses with many metals, forming alloys called amalgams. Mercury in water and acidic solutions does not dissolve; only nitric acid or nitric acid can do this.

This can be done with difficulty using sulfuric acid. When the temperature reaches 300º C, a reaction occurs with oxygen, the result of which is mercury oxide, which is red in color (not to be confused with the fictional “red mercury”!).

"Red Mercury"– this term refers to a substance invented for commercial purposes. Exorbitant properties are attributed to the property; in fact, science does not yet know a similar metal, either natural or artificial. Compound of sulfur and mercury at high temperatures forms mercury sulfide.

Extraction and origin of mercury

This metal is considered quite rare and is concentrated mainly in specific mercury ores, the amount of mercury in which is quite high. By and large, the entire volume of natural mercury is scattered in nature, and only a small part of it is contained in ores. The highest percentage of content is observed in rocks formed after the eruption and sedimentary shales.

Sulfide minerals also mostly contain mercury. These are faded ores, sphaleriates, realgars and stibnites. In nature, bundles of elements accompanying each other are often found, for example, such a neighborhood as selenium, sulfur and mercury.

At least twenty types of mercury minerals are known for certain. The main mined mineral is cinnabar, less commonly metacinnabarite or native mercury. Livingstonite is mined at a deposit in Mexico (Guitzuco).

The largest deposits are located in Dagestan, Tajikistan, Armenia, Kyrgyzstan, Ukraine, Spain and Slovenia (the deposit in the city of Idriya is considered the largest since the Middle Ages). There are also at least twenty-three deposits in Russia.

Uses of mercury

Previously defined mercury compound, for example its chloride or mercusal, could easily find application in the medical field. These were various medications with laxative, diuretic and antiseptic effects. But now mercury compounds are almost completely forced out of this area due to their toxicity. This element is partially used in the production of thermometers, although a safer substitute has already been found for them.

Its presence in technical devices is considered more acceptable. These are high-precision thermometers for technical purposes. Fluorescent light lamps that use its vapors. Rectifiers, electric drives, and even some models of welding machines. These are position sensors and sealed switches.

It is also used in the manufacture of certain types of current sources with mercury-zinc filling. One of the components of hydrodynamic bearings is also mercury. Also in the technical industry, compounds such as fulminate, iodide and mercury bromide have found their use. Positive properties were shown with cesium used in the production of ion engines.

In metallurgy, mercury is used in the smelting of many different alloys and in the secondary processing of aluminum. It has found its niche in jewelry production, as well as in the manufacture of mirrors. Mercury has become widespread in the production of gold; gold-bearing rocks are pre-treated with it to extract it from them. In rural industry, some mercury compounds are used for processing seed material and as a pesticide. Although this is highly undesirable.

Harm of mercury to the human body

Mercury vapor is extremely dangerous. It can enter the body through evaporation or directly through the oral cavity. The latter usually happens with young children, if mercury broke from a thermometer. In this case, it is necessary to induce vomiting as soon as possible and call emergency help.

But everyone can inhale its vapors if mercury from a thermometer rolled through all the cracks of the room, and evaporated from there. Mercury poisoning occurs gradually, in the initial stages no special symptoms are observed. Subsequently, excessive irritability, constant nausea, and weight loss occur. First of all, the impact falls on the central nervous system and kidneys.

What precautions does it require? mercury? Did you break the thermometer? What to do and how to collect mercury from the floor, the following instructions will indicate. Ventilate the room immediately for at least several hours. But do not allow a direct draft until the mercury is completely collected. Limit access to the scene to avoid spreading mercury throughout the house.

Before you start collecting mercury, you need to put on gloves made of impermeable material on your hands, any bags on your feet, and a bandage soaked in water or solution on your face. Carefully collect all the rolled mercury and the remains of the broken thermometer in a container with water, this will prevent the mercury from evaporating. It is necessary to collect the mercury as carefully as possible, for example, using a syringe.

If mercury gets under the baseboard or floor, don’t be lazy to open it and clean it out, no matter how long it takes. If the procedure takes enough time, you should take breaks every ten minutes. The container must be tightly sealed and kept away from heat. Throwing away the container is strictly prohibited. It will pollute the environment and children may find it. Therefore, the collected mercury is handed over to the appropriate services.

The scene of the incident is treated with manganese solution or diluted bleach. You cannot collect mercury with a broom or vacuum cleaner, this will only make the situation worse by spraying mercury over a large area. In addition, after this the vacuum cleaner will be unusable due to toxic contamination.

Mercury price

The total volumes from trade in this rare earth metal and its various compounds are about 150 million dollars, with world reserves of about 300 thousand tons. Due to the liquidation of some major deposits, supplies of mercury to the world market have sharply decreased, which has led to a rise in prices for these products. For comparison, in 2001, a standard measuring container with a volume of 34.5 kg cost $170, by 2005 the price reached $775. After which it began to decline again, the latest prices were about $550.

The solution in this case was secondary mercury produced at key enterprises. The latest technologies have provided the market with a large volume of cheaper products, which has made it possible to somewhat reduce the exorbitantly increased prices for mercury of natural origin. Although prices still remain at a fairly high level.