SULFUR, S (sulfur), a non-metallic chemical element, a member of the chalcogen family (O, S, Se, Te and Po) - Group VI of the Periodic Table of Elements. Sulfur, like many of its uses, has been known since ancient times. A. Lavoisier argued that sulfur is an element. Sulfur is vital for the growth of plants and animals, it is part of living organisms and their decomposition products, it is abundant, for example, in eggs, cabbage, horseradish, garlic, mustard, onions, hair, wool, etc. It is also present in coals and oil.

Application.

About half of the annual consumption of sulfur goes to the production of industrial chemicals such as sulfuric acid, sulfur dioxide and carbon disulphide (carbon disulphide). In addition, sulfur is widely used in the production of insecticides, matches, fertilizers, explosives, paper, polymers, paints and dyes, and in the vulcanization of rubber. The leading place in the production of sulfur is occupied by the USA, the CIS countries and Canada.

distribution in nature.

Sulfur occurs in a free state (native sulfur). In addition, there are huge reserves of sulfur in the form of sulfide ores, primarily ores of lead (lead sheen), zinc (zinc blende), copper (copper sheen), and iron (pyrite). When metals are extracted from these ores, sulfur is usually removed by roasting in the presence of oxygen, which produces sulfur (IV) dioxide, which is often released into the atmosphere without use. In addition to sulfide ores, a lot of sulfur is found in the form of sulfates, for example, calcium sulfate (gypsum), barium sulfate (barite). Sea water and many mineral waters contain water-soluble magnesium and sodium sulfates. Hydrogen sulfide (hydrogen sulfide) is found in some mineral waters. In industry, sulfur can be obtained as a by-product of processes in smelters, coke ovens, oil refining, from flue or natural gases. Sulfur is extracted from natural underground deposits by melting it with superheated water and delivering it to the surface with compressed air and pumps. In the frash process for the extraction of sulfur from sulfur-bearing deposits in a concentric tube installation patented by G. Frasch in 1891, sulfur is obtained with a purity of up to 99.5%.

Properties.

Sulfur has the form of a yellow powder or brittle crystalline mass, odorless and tasteless and insoluble in water. Sulfur has several allotropic modifications. The following are best known: crystalline sulfur - rhombic (native sulfur, a-S) and monoclinic (prismatic sulfur, b-S); amorphous - colloidal (sulfuric milk) and plastic; intermediate amorphous-crystalline - sublimated (sulfur color).

Table: PROPERTIES OF SULFUR

Crystalline sulfur.

Crystalline sulfur has two modifications; one of them, rhombic, is obtained from a solution of sulfur in carbon disulfide (CS2) by evaporation of the solvent at room temperature. In this case, diamond-shaped translucent crystals of light yellow color are formed, easily soluble in CS2. This modification is stable up to 96°C; at higher temperatures, the monoclinic form is stable. During natural cooling of molten sulfur in cylindrical crucibles, large crystals of rhombic modification with a distorted shape grow (octahedrons, in which corners or faces are partially “cut off”). Such material is called lump sulfur in the industry. The monoclinic modification of sulfur is long, transparent, dark yellow, acicular crystals, also soluble in CS2. When monoclinic sulfur is cooled below 96 ° C, a more stable yellow rhombic sulfur is formed.

non-crystalline sulfur.

In addition to these crystalline and amorphous forms, there is an intermediate form known as sulfur color or sublimated sulfur, which is obtained by condensing sulfur vapor without passing through the liquid phase. It consists of tiny grains with a crystallization center and an amorphous surface. This form is slowly and incompletely soluble in CS2. After treatment with ammonia to remove impurities such as arsenic, a product known medically as washed sulfur is obtained, which is used in a similar way to colloidal sulfur.

The sulfur content in the human body (body weight 70 kg) is 140 g. A person needs about 1 g per day, and this is satisfied with the usual diet. The sulfur content of foods is generally proportional to their protein content. Sulfur is found in legumes, oatmeal, wheat, eggs, meat, fish and milk. Most of the sulfur enters the body in the form of amino acids and is excreted mainly in the urine in the form of the SO42- ion.

The biological role of sulfur

Sulfur is a part of proteins in the form of sulfur-containing amino acids (essential amino acid methionine), cystine, as well as some hormones and vitamins, participates in redox processes in the body. It is part of the cartilage tissue, hair, nails. With a lack of sulfur in the body, brittle bones and hair loss are observed. Sulfur is necessary for the neutralization of toxic substances in the liver that come as a result of decay.

The use of sulfur compounds in medicine

Sulfur compounds can serve as medicines.

Sodium thiosulfate Na2S2O3 is an antidote against heavy metals in the body.

Finely dispersed sulfur is the basis of ointments, used in the treatment of fungal diseases.

Glauber's salt Na2SO4 ∙10H2O is a laxative and choleretic agent.

Hydrogen sulfide baths. In the mineral water of the sources of hydrogen sulfide thermal waters of Matsesta (Sochi), many different substances are dissolved, but its chemical appearance is determined by sodium, chlorine and hydrogen sulfide; thanks to the latter, the water has a pungent smell. Reddening of the skin is a response to the action of gas: the vessels dilate, they receive a lot of oxygen-rich blood, and blood circulation improves. Hydrogen sulfide in the water of Matsesta is present in 2 states - in the form of H2S molecules and hydrosulfide ions HS-.

Back in the days of A.S. Pushkin, bathing in the sulfuric (warm and hot) springs of Mount Mashuk was very popular, which he reflected in his works:

Mashuk, the giver of healing jets;

Around its magical streams

A pale swarm crowds the sick;

Who is the victim of military honor,

Who are cheering, who are Cyprian;

The sufferer thinks the thread of life

Strengthen in miraculous waves,

Coquette of evil years of resentment

Leave at the bottom, and the old man

Rejuvenate - at least for a moment.

Sulfur (Sulphur - designation "S" in the periodic table) is a highly electronegative element that exhibits non-metallic properties. In hydrogen and oxygen compounds, it is part of various anions, forms many acids and salts. Most sulfur-containing salts are sparingly soluble in water.

Natural sulfur minerals

Sulfur is the fifteenth most abundant element in the earth's crust. It occurs in the free (native) state and bound form.

The most important natural sulfur compounds are FeS2 - iron pyrite, pyrite, ZnS - zinc blende, PbS - lead luster, HgS - cinnabar, CaSO4 H2O - gypsum, Na2SO4 10H2O - Glauber's salt, MgSO4 7H2O - bitter salt.

It is part of various minerals, ores and rocks, oil, natural coal. Sulfur is the sixth element in terms of content in natural waters, it occurs mainly in the form of a sulfate ion and determines the “permanent” hardness of fresh water. Vital element for higher organisms, component many proteins, concentrated in the hair.

History of the origin of the name

The origin of the Latin sulfur is unknown. The Russian name of the element is usually derived from the Sanskrit "sire" - light yellow. Perhaps the relationship of "sulphur" with the Hebrew "seraphim" - pl. number from "seraph" - letters. burning, and sulfur burns well. In Old Russian and Old Slavonic, "sulfur" is generally a combustible substance, including fat.

Receipt

Sulfur is obtained mainly by smelting native sulfur directly in places where it occurs underground. Sulfur ores are mined different ways- depending on the conditions of occurrence. Sulfur deposits are almost always accompanied by accumulations of poisonous gases - sulfur compounds. In addition, we must not forget about the possibility of its spontaneous combustion.

Ore mining in an open way is as follows. Walking excavators remove layers of rocks under which ore lies. The ore layer is crushed by explosions, after which the ore blocks are sent to a sulfur smelter, where sulfur is extracted from the concentrate.

In 1890, Hermann Frasch proposed to melt sulfur underground and pump it to the surface through wells similar to oil wells. The relatively low (less than 120°C) melting point of sulfur confirmed the reality of Frasch's idea. In 1890, tests began that led to success.

There are several methods for obtaining sulfur from sulfur ores: steam-water, filtration, thermal, centrifugal and extraction.

Physical Properties

Natural intergrowth of crystals of native sulfur

Sulfur differs significantly from oxygen in its ability to form stable homochains. The most stable are cyclic S8 molecules, which have the shape of a crown and form rhombic and monoclinic sulfur. This is crystalline sulfur - a brittle yellow substance. In addition, molecules with closed (S4, S6) chains and open chains are possible. Such a composition has plastic sulfur, a brown substance. Sulfur is insoluble in water, some of its modifications dissolve in organic solvents, such as carbon disulfide.

Sulfur is used for the production of sulfuric acid, rubber vulcanization, as a fungicide in agriculture, and as colloidal sulfur - a drug.

Chemical properties

At room temperature, sulfur reacts with fluorine, chlorine and concentrated oxidizing acids (HNO3, H2SO4), exhibiting reducing properties:

S + 6HNO3(conc.) = H2SO4 + 6NO2 + 2H2O

S + 2H2SO4(conc.) = 3SO2 + 2H2O

In air, sulfur burns, forming sulfur dioxide - a colorless gas with a pungent odor:

When interacting with metals, it forms sulfides.

When heated, sulfur reacts with carbon, silicon, phosphorus, hydrogen:

C + 2S = CS2 (carbon disulfide)

Sulfur dissolves in alkalis when heated - disproportionation reaction

3S + 6KOH = K2SO3 + 2K2S + 3H2O

Practical part.

Home experiment:

Cabbage accumulates 0.0008% sulfur. Weigh a fork of cabbage and calculate how much sulfur it contains.

My sister and I were not interested in doing this task just like that, and we decided to compose a fairy tale. We remade the fairy tale about the kolobok in a different way.

Characters: kolobok, an old man with an old woman, D. I. Mendeleev and, of course, a storyteller. The storyteller tells a story:

The story of how a gingerbread man turned into a cabbage.

There once was a Kolobok. He lived, lived, but contrary to the fairy tale, no one wanted to eat him. It turns out that everyone - the hare, the fox, the wolf, the bear, and even the grandmother and grandfather went on a low-carbohydrate diet, excluding bakery and pasta from their diet. "Life without bread!!!" they held a poster in their hand. And on the dining table there was a large basket full of vegetables, beans and peas grew in the garden.

Gingerbread man was crying, he was very worried about this. There was no limit to the grief of Kolobok. And he decided to change, so that he was eaten, as it should be in a fairy tale. He decided to turn into cabbage, because the inhabitants of the forest ate it in kilograms. Our hero found out that cabbage contains a lot of beta-carotene, folate, iron, sulfur, calcium, vitamins A and C. I bought all these minerals and vitamins at the Kolobok pharmacy and began to use them three times a day after meals. Soon, the composition of Kolobok completely coincided with the composition of cabbage: it began to turn green.

However, there was one problem: Kolobok, by no means, could calculate how many percent sulfur should be in his body. He had a hard time with math. And he decided to write a letter to the great Mendeleev himself, hoping that he would help him. And indeed! Three days later, the following answer came from the chemist:

Dear Kolobok! Very happy to help you!

Let x be your body mass, then:

The mass fraction of sulfur will be equal to the product of this and the mass fraction of sulfur 0.0008%.

Divide what you get by 100.

Mendeleev.

So, in the end, having made the calculations, Gingerbread Man took so much sulfur that he finally became cabbage and was safely eaten.

That's the end of the tale, and who listened - well done!

From the history of the use of the properties of sulfur by man, it is known that even priests ancient egypt used sulfur and its compounds (sulfides) to create a magical, mysterious atmosphere, fumigating it with vapors in the rooms of cult halls where religious rites were held.

In some clinical cases, sulfur treatment is indeed the best remedy, the possibilities of which we will consider in this article.

The healing properties of sulfur

The macroelement sulfur is considered a biogenic chemical element, i.e., it is normally present in tissues human body. Sulfur is a yellow powder. The name of this element probably comes from the Sanskrit word "sira" meaning "light yellow". In nature, there are several structural isomers of sulfur that differ from each other in the configuration of the molecule. These include rhombic and monoclinic varieties of sulfur. Natural compounds containing sulfur are successfully used in medicine.

In total, the body of an adult contains 0.25% of sulfur from the total body weight. Most sulfur in the bone and cartilage system, hair and skin, bile, nervous tissue.

So, in the course of clinical studies it has been proven that the treatment with sulfur in the presence of arthritis, convulsions and muscle spasms, osteochondrosis, the compound methylsulfonylmethane, which is a rich natural storehouse of sulfur, has a therapeutic effect. Such a healing effect of sulfur, which is part of the compound, is explained by the content of glucosamine sulfate and chondroitin sulfate in cartilage and bone tissues. These substances provide elasticity and structural organization of the cartilage and ligamentous apparatus.

The Greeks in ancient times used to intimidate and gain military advantage weapons that fire a composition that includes sulfur. The great Homer has notes in his writings, where he writes about the action of sulfur combustion products that is dangerous for human health and life.

Indications and contraindications for sulfur treatment

It is important to constantly supply the body with food of the required amount of sulfur and its compounds. 0.5-1 g of sulfur should be supplied to the human body per day with food. Sulfur entering the body is used to build new protein molecules, many enzymes, polypeptides (insulin molecules synthesized in the pancreas).

Sulfur is involved in the metabolic process together with B vitamins. Neurasthenia may be the result of sulfuric macroelementosis caused by insufficient intake of sulfur in the body.

The use of sulfuric ointment is contraindicated in case of hypersensitivity to sulfur and pregnancy.

The use of combustible sulfur in medicine

In medicine, sulfur-containing substances are used both for preventive and therapeutic purposes to eliminate skin lesions. Outwardly in the form of ointments and powders, precipitated sulfur is used. Sulfur ointment (5-10-20%) is used to treat many skin diseases (sycosis, seborrhea, psoriasis), relieve manifestations of an allergic reaction on the skin, and treat scabies.

Purified sulfur is used in clinical practice as an antihelminthic (for enterobiasis), for the treatment of constipation, and also as an external agent in the treatment of scabies and seborrhea.

Foods rich in sulfur (garlic, cabbage, onions, egg yolks, buckwheat, gooseberries, chili peppers) are desirable to eat with brittle nails, to increase the shine and strength of hair. The inclusion of these foods in the daily diet is also shown with a high level of triglycerides (sources of fat) and blood sugar, pain in the joints.

Treatment of sulfur fuel in practice

Sulfur is an important nutrient found in all living organisms. This substance is part of the protein, primarily amino acids, as well as vitamins (B1 and U) and hormones. With sulfur deficiency in the diet, there is an increase in blood sugar and fat levels, joint pain, aging processes are accelerated, hair becomes dull, and nails become brittle.

Sulfur as an element plays an important role in energy production, blood coagulation and purification, in the synthesis of collagen (the main protein that forms the basis for bones, cartilage), fibrous tissues, skin, hair and nails, as well as in the formation of enzymes. Sulfur promotes the brain and cellular activity, has an anti-allergic effect, stimulates cellular respiration.

Sulfur is excreted from the body with feces and urine in the form of inorganic sulfates and in a small amount in the form of hydrogen sulfide by the skin and lungs, imparting an unpleasant odor to sweat and exhaled air. The daily need for sulfur, as a rule, is satisfied through good nutrition. A lot of sulfur is found in poppy seeds, meat, fish, eggs, soybeans, peas, wheat, milk, apples, grapefruits, onions.

The superficial layers of the skin are especially rich in sulfur. Sulfur is contained here in keratin (hair includes up to 5-10% keratin), as well as in melanin, a pigment; which in the form of a tan protects the deep layers of the skin from the harmful effects of ultraviolet radiation.

Sulfur Treatment: Recipes

Purified sulfur in powder form is used in folk medicine: sulfur treatment is used mainly for skin diseases, 1 g 3 times a day.

For the treatment of gray diathesis in children, as well as eczema in adults, an ointment can be prepared from sulfur powder and sour cream.

Required: 1 tsp. sulfur powder, 1 tsp. sour cream.

Cooking. Mix the ingredients.

Application. Use the composition at night, smearing the body and affected areas after taking a warm bath, to which a little potassium permanganate, horse sage decoction or celandine is added. Do not forget that sulfur treatment, like any other, should be prescribed by your doctor.

Sulfur is one of the few substances that the first "chemists" operated on several thousand years ago. She began to serve humanity long before she occupied cell No. 16 in the periodic table.

Many old books tell about one of the most ancient (albeit hypothetical!) uses of sulfur. Both the New and Old Testaments depict sulfur as a source of heat during the heat treatment of sinners. And if books of this kind do not give sufficient grounds for archaeological sites in search of the remnants of paradise or hellfire, then their testimony that the ancients were familiar with sulfur and some of its properties can be taken for granted.

One of the reasons for this fame is the prevalence of native sulfur in countries ancient civilizations. The deposits of this yellow combustible substance were developed by the Greeks and Romans, especially in Sicily, which until the end of the last century was mainly famous for sulfur.

Since ancient times, sulfur has been used for religious and mystical purposes, it was lit in various ceremonies and rituals. But just as long ago, element No. 16 also acquired quite mundane purposes: weapons were inked with gray, it was used in the manufacture of cosmetic and medicinal ointments, it was burned to bleach fabrics and to fight insects. Sulfur mining increased significantly after black powder was invented. After all, sulfur (together with coal and saltpeter) is its indispensable component.

And now gunpowder production consumes a part of the extracted sulfur, though very small. Nowadays, sulfur is one of the most important raw materials for many chemical industries. And this is the reason for the continuous growth of world sulfur production.

Origin of sulfur

Large accumulations of native sulfur are not so common. More often it is present in some ores. Native sulfur ore is a rock interspersed with sulfur.

When did these inclusions form - simultaneously with accompanying rocks or later? The direction of prospecting and exploration works depends on the answer to this question. But, despite the millennia of communication with sulfur, humanity still does not have a clear answer. There are several theories, the authors of which hold opposing views.

The theory of syngenesis (i.e., the simultaneous formation of sulfur and host rocks) suggests that the formation of native sulfur occurred in shallow water basins. Special bacteria reduced sulfates dissolved in water to hydrogen sulfide, which rose up, entered the oxidizing zone, and here it was oxidized chemically or with the participation of other bacteria to elemental sulfur. The sulfur settled to the bottom, and subsequently the sulfur-containing id formed the ore.

The theory of epigenesis (sulfur inclusions formed later than the main rocks) has several options. The most common of them suggests that groundwater, penetrating through the rock masses, is enriched with sulfates. If such waters come into contact with oil or natural gas deposits, then sulfate ions are reduced by hydrocarbons to hydrogen sulfide. Hydrogen sulfide rises to the surface and, oxidizing, releases pure sulfur in voids and cracks in rocks.

In recent decades, one of the varieties of the theory of epigenesis, the theory of metasomatosis, has been finding more and more confirmation (translated from Greek, “metasomatosis” means “replacement.” According to it, gypsum CaSO 4 2H 2 O and anhydrite CaSO 4 are constantly being converted into sulfur and calcite CaCO 3 This theory was created by Soviet scientists L. M. Miropolsky and B. P. Krotov in 1935. In particular, this fact speaks in favor of it.

In 1961, the Mishrak field was discovered in Iraq. Sulfur here is enclosed in carbonate rocks, which form a vault supported by outgoing supports (in geology they are called wings). These wings are composed mainly of anhydrite and gypsum. The same picture was observed at the domestic Shor-Su field.

The geological originality of these deposits can only be explained from the standpoint of the theory of metasomatism: primary gypsum and anhydrite have turned into secondary carbonate ores interspersed with native sulfur. Not only the proximity of minerals is important - the average sulfur content in the ore of these deposits is equal to the content of chemically bound sulfur in anhydrite. And studies of the isotopic composition of sulfur and carbon in the ore of these deposits gave additional arguments to supporters of the theory of metasomatism.

But there is one “but”: the chemistry of the process of converting gypsum into sulfur and calcite is not yet clear, and therefore there is no reason to consider the theory of metasomatism the only correct one. There are lakes on Earth even now (in particular, Sulfur Lake near Sernovodsk), where syngenetic deposition of sulfur occurs and sulfur-bearing sludge does not contain either gypsum or anhydrite.

All this means that the variety of theories and hypotheses about the origin of native sulfur is the result not only and not so much of the incompleteness of our knowledge, but the complexity of the phenomena occurring in the depths. Even from elementary school mathematics, we all know that different paths can lead to the same result. This law also applies to geochemistry.

Sulfur mining

Sulfur ores are mined in different ways - depending on the conditions of occurrence. But in any case, you have to pay a lot of attention to safety. Sulfur deposits are almost always accompanied by accumulations of poisonous gases - sulfur compounds. In addition, we must not forget about the possibility of its spontaneous combustion.

Ore mining in an open way is as follows. Walking excavators remove layers of rocks under which ore lies. The ore layer is crushed by explosions, after which the ore blocks are sent to the processing plant, and from there to the sulfur smelter, where sulfur is extracted from the concentrate. Extraction methods are different. Some of them will be discussed below. And here it is appropriate to briefly describe the borehole method of extracting sulfur from underground, which allowed the United States of America and Mexico to become the largest suppliers of sulfur.

At the end of the last century, the richest deposits of sulfur ore were discovered in the south of the United States. But it was not easy to approach the layers: hydrogen sulfide leaked into the mines (namely, the mine was supposed to develop the deposit) and blocked access to sulfur. In addition, sandy swimmers prevented breaking through to the sulfur-bearing strata. A solution was found by the chemist Herman Frasch, who proposed to melt sulfur underground and pump it to the surface through wells similar to oil wells. The relatively low (less than 120°C) melting point of sulfur confirmed the reality of Frasch's idea. In 1890, tests began that led to success.

In principle, Frasch's installation is very simple: a pipe in a pipe. Superheated water is supplied to the space between the pipes and flows through it into the reservoir. And molten sulfur rises through the inner pipe, heated from all sides. The modern version of the Frasch installation is supplemented by a third - the narrowest pipe. Through it, compressed air is supplied to the well, which helps to raise the molten Sulfur to the surface. One of the main advantages of the Frasch method is that it allows obtaining relatively pure sulfur already at the first stage of production. When mining rich ores, this method is very effective.

It was previously believed that the method of underground sulfur smelting was applicable only in the specific conditions of the "salt domes" of the Pacific coast of the United States and Mexico. However, experiments conducted in Poland and the USSR refuted this opinion. In Poland, a large amount of sulfur is already being extracted by this method: in 1968, the first sulfur wells were put into operation in the USSR as well.

And the ore obtained in quarries and mines has to be processed (often with preliminary enrichment), using various technological methods for this.

There are several methods for obtaining sulfur from sulfur ores: steam-water, filtration, thermal, centrifugal and extraction.

Thermal methods of sulfur recovery are the oldest. Back in the 18th century in the Kingdom of Naples, sulfur was smelted in heaps - “solfatars”. Until now, sulfur is smelted in Italy in primitive furnaces - "calcarons". The heat needed to smelt sulfur from ore is obtained by burning part of the mined sulfur. This process is inefficient, losses reach 45%.

Italy became the birthplace of steam and water methods for extracting sulfur from ores. In 1859, Giuseppe Gill received a patent for his apparatus, the forerunner of today's autoclaves. The autoclave method (significantly improved, of course) is still used in many countries.

In the autoclave process, enriched sulfur ore concentrate, containing up to 80% sulfur, is pumped into the autoclave in the form of a liquid pulp with reagents. Water vapor is supplied there under pressure. The pulp is heated up to 130°C. The sulfur contained in the concentrate melts and separates from the rock. After a short settling, the smelted sulfur is drained off. Then “tails” are released from the autoclave - a suspension of waste rock in water. The tailings contain quite a lot of sulfur and are returned to the processing plant.

In Russia, the autoclave method was first used by engineer K.G. Patkanov in 1896

Modern autoclaves are huge apparatuses as high as a four-story building. Such autoclaves are installed, in particular, at the sulfur-smelting plant of the Rozdil Mining and Chemical Combine in the Carpathian region.

In some industries, for example, at a large sulfur plant in Tarnobrzeg (Poland), waste rock is separated from molten sulfur on special filters. The method of separating sulfur and waste rock in centrifuges has been developed in our country. In a word, “gold ore (more precisely, golden ore) can be separated from empty rock” in different ways.

IN Lately more and more attention is paid to borehole geotechnological methods of sulfur extraction. At the Yazovsky deposit in the Carpathian region, sulfur - a classic dielectric - is melted underground with high-frequency currents and pumped to the surface through wells, as in the Frasch method. Scientists of the Institute of Mining and Chemical Raw Materials have proposed a method for underground gasification of sulfur. According to this method, sulfur is ignited in the reservoir, and sulfur dioxide is pumped to the surface, which is used to produce sulfuric acid and other useful products.

Different countries satisfy their needs for sulfur in different ways. Mexico and the United States mainly use the Frache method. Italy, which occupies the third place in the production of sulfur among the capitalist states, continues to extract and process (by various methods) sulfur ores from the Sicilian deposits and the Marche province. Japan has significant reserves of sulfur of volcanic origin. France and Canada, which do not have native sulfur, have developed a large-scale production of it from gases. There are no own sulfur deposits in England and Germany either. They cover their needs for sulfuric acid by processing sulfur-containing raw materials (mainly pyrite), and import elemental sulfur from other countries.

The Soviet Union and the socialist countries fully satisfy their needs thanks to their own sources of raw materials. After the discovery and development of the rich Carpathian deposits, the USSR and Poland significantly increased the production of sulfur. This industry continues to grow. IN last years new large enterprises were built in the Ukraine, old plants on the Volga and in Turkmenistan were reconstructed, and the production of sulfur from natural gas and waste gases was expanded.

Crystals and macromolecules

The fact that sulfur is an independent chemical element, and not a compound, was first convinced by the great French chemist Antoine Laurent Lavoisier in the 18th century.

Since then, the concept of sulfur as an element has not changed very much, but has significantly deepened and supplemented.

Element 16 is now known to consist of a mixture of four stable isotopes with mass numbers 32, 33, 34 and 36. It is a typical non-metal.

Lemon yellow crystals of pure sulfur are translucent. The shape of the crystals is not always the same. The most common is rhombic sulfur (the most stable modification) - the crystals look like octahedrons with cut corners. All other modifications are converted into this modification at room (or close to room) temperature. It is known, for example, that crystallization from a melt (sulfur melting point 119.5° C.) first produces acicular crystals (monoclinic form). But this modification is unstable, and at a temperature of 95.6°C it becomes rhombic. A similar process occurs with other modifications of sulfur.

Recall the well-known experience - obtaining plastic sulfur.

If molten sulfur is poured into cold water, an elastic, rubber-like mass is formed. It can also be obtained in the form of threads. But a few days pass, and the mass recrystallizes, becomes hard and brittle.

Molecules of sulfur crystals always consist of eight atoms (S 8), and the difference in the properties of sulfur modifications is explained by polymorphism - the unequal structure of crystals. The atoms in the sulfur molecule are built in a closed cycle, forming a kind of crown. When melting, the bonds in the cycle break, and cyclic molecules turn into linear ones.

The unusual behavior of sulfur during melting is given various interpretations. One of them is this. At temperatures from 155 to 187°C, a significant increase in molecular weight seems to occur, this is confirmed by a multiple increase in viscosity. At 187°C, the viscosity of the melt reaches almost a thousand poise, almost a solid is obtained. A further increase in temperature leads to a decrease in viscosity (molecular weight drops).

At 300°C, sulfur again turns into a fluid state, and at 444.6°C it boils.

For sulfur vapor, the number of atoms in the molecule gradually decreases with increasing temperature: S8 → S6 → S4 → (800°C) S 2 . At 1700°C, sulfur vapor is monatomic.

Briefly about sulfur compounds

In terms of prevalence, element No. 16 takes 15th place. The sulfur content in the earth's crust is 0.05% by weight. This is a lot.

In addition, sulfur is chemically active and reacts with most elements. Therefore, sulfur occurs in nature not only in the free state, but also in the form of various inorganic compounds. Sulfates (mainly alkali and alkaline earth metals) and sulfides (iron, copper, zinc, lead) are especially common. Sulfur is also found in coals, shale, oil, natural gases, in the organisms of animals and plants.

When sulfur interacts with metals, as a rule, quite a lot of heat is released. In reactions with oxygen, sulfur gives several oxides, of which the most important SO 2 and SO 3 are anhydrides of sulfurous H 2 SO 3 and sulfuric H 2 SO 4 acids. The combination of sulfur with hydrogen - hydrogen sulfide H 2 S - is a very poisonous fetid gas, always present in places of decay of organic residues. The earth's crust in places located near sulfur deposits often contains quite significant amounts of hydrogen sulfide. In aqueous solution, this gas has acidic properties. It is impossible to store its solutions in air, it oxidizes with the release of sulfur:

2H 2 S + O 2 → 2H 2 O + 2S.

Hydrogen sulfide is a strong reducing agent. This property is used in many chemical industries.

What is sulfur for?

Among the things that surround us, there are few such for the manufacture of which sulfur and its compounds would not be needed. Paper and rubber, ebonite and matches, fabrics and medicines, cosmetics and plastics, explosives and paint, fertilizers and pesticides - this is not a complete list of things and substances for the production of which element No. 16 is needed. In order to make, for example, a car, you need to use about 14 kg of sulfur. It can be said without exaggeration that the industrial potential of the country is quite accurately determined by the consumption of sulfur.

A significant part of the world's sulfur production is absorbed by the paper industry (sulfur compounds help to isolate cellulose). In order to produce 1 ton of cellulose, you need to spend more than 100 kg of sulfur. The rubber industry also consumes a lot of elemental sulfur - for the vulcanization of rubbers.

In agriculture, sulfur is used both in elemental form and in various compounds. It is part of mineral fertilizers and preparations for pest control. Along with phosphorus, potassium and other elements, sulfur is necessary for plants. However, most of the sulfur introduced into the soil is not absorbed by them, but helps to absorb phosphorus. Sulfur is introduced into the soil along with phosphate rock. The bacteria present in the soil oxidize it, the resulting sulfuric and sulfurous acids react with phosphorites, and as a result, phosphorus compounds are obtained that are well absorbed by plants.

However, the main consumer of sulfur is the chemical industry. Approximately half of the sulfur mined in the world goes to the production of sulfuric acid. To get 1 ton of H 2 SO 4 , you need to burn about 300 kg of sulfur. And the role of sulfuric acid in the chemical industry is comparable to the role of bread in our diet.

A significant amount of sulfur (and sulfuric acid) is consumed in the manufacture of explosives and matches. Pure, free from impurities, sulfur is needed for the production of dyes and luminous compounds.

Sulfur compounds are used in the petrochemical industry. In particular, they are necessary in the production of anti-knock agents, lubricants for ultra-high pressure equipment; cooling oils that accelerate metal processing sometimes contain up to 18% sulfur.

The enumeration of examples confirming the paramount importance of element No. 16 could be continued, but "one cannot grasp the immensity." Therefore, we mention in passing that sulfur is also necessary for such industries as mining, food, textiles, and - put an end to it.

Our century is considered the century of "exotic" materials - transuranium elements, titanium, semiconductors, and so on. But outwardly unpretentious, long-known element number 16 continues to be absolutely necessary. It is estimated that 88 out of 150 major chemical products use either sulfur itself or its compounds in the production.

From ancient and medieval books

“Sulfur is used to cleanse dwellings, since many are of the opinion that the smell and burning of sulfur can protect against all sorts of sorceries and drive away all evil spirits.”

Pliny the Elder, Natural History, 1st cent. AD

“If the grasses are stunted, poor in sap, and the branches and foliage of the trees are dull, dirty, darkish in color instead of a brilliant green, this is a sign that the subsoil is replete with minerals in which sulfur predominates.”

“If the ore is very rich in sulfur, it is lit on a wide iron sheet with many holes through which the sulfur flows into pots filled to the brim with water.”

"Sulfur is also part of a terrible invention - a powder that can throw pieces of iron, bronze or stone far ahead - the weapon of war of the new mud."

Agricola, On the Mineral Kingdom, 16th century.

How sulfur was tested in the 14th century

“If you want to test sulfur, whether it is good or not, then take a piece of sulfur in your hand and put it to your ear. If sulfur crackles so that you hear it crackle, then it is good; if sulfur is silent and does not crack, then it is not good ... "

This peculiar method of determining the quality of the material by ear (as applied to sulfur) can be used now. It was experimentally confirmed that only sulfur containing no more than one percent of impurities "cracks". Sometimes the matter is not limited only to cracking - a piece of sulfur breaks into pieces.

Asphyxiating sulfuric gas

As you know, the outstanding naturalist of antiquity Pliny the Elder died in 79 AD. during a volcanic eruption. His nephew, in a letter to the historian Tacitus, wrote: “...Suddenly there were peals of thunder, and black sulfuric vapors rolled down from the mountain flame. Everyone fled. Pliny got up and, leaning on two slaves, thought to leave too; but the deadly steam surrounded him on all sides, his knees buckled, he fell again and suffocated.

The "black sulfur fumes" that killed Pliny did not, of course, consist only of vaporous sulfur. Volcanic gases include both hydrogen sulfide and sulfur dioxide. These gases have not only a pungent odor, but also great toxicity. Hydrogen sulfide is especially dangerous. In its pure form, it kills a person almost instantly. The danger is great even with an insignificant (about 0.01%) content of hydrogen sulfide in the air. Hydrogen sulfide is all the more dangerous because it can accumulate in the body. It combines with iron, which is part of hemoglobin, which can lead to severe oxygen starvation and death. Sulfur dioxide (sulfur dioxide) is less toxic, but its release into the atmosphere led to the fact that all vegetation around the metallurgical plants died. Therefore, in all enterprises producing or using these gases; special attention is paid to safety issues.

Sulfur dioxide and straw hat

Combining with water, sulfur dioxide forms weak sulfurous acid H 2 SO 3, which exists only in solutions. Sulfur dioxide will decolorize many dyes in the presence of moisture. This property is used for bleaching wool, silk, straw. But such compounds, as a rule, do not have great durability, and white straw hats eventually acquire the original dirty yellow color.

Sulfur dioxide SO 3 under normal conditions is a colorless, highly volatile liquid, boiling at 44.8°C. It hardens at -16.8°C and becomes very similar to ordinary ice. But there is another - a polymer modification of solid sulfuric anhydride (in this case, its formula should be written (SO 3) n). Outwardly, it is very similar to asbestos, its fibrous structure is confirmed by x-rays. This modification does not have a strictly defined melting point, which indicates its heterogeneity.

Plaster and alabaster

Gypsum CaSO 4 2H 2 O is one of the most common minerals. But the “gypsum splints” common in medical practice are made not from natural gypsum, but from alabaster. Alabaster differs from gypsum only in the amount of water of crystallization in the molecule, its formula is 2CaSO 4 H 2 O. When “cooking” alabaster (the process takes place at 160 ... 170 ° C for 1.5 ... quarters of water of crystallization, and the material acquires astringent properties. Alabaster greedily captures water, while rapid random crystallization occurs. The crystals do not have time to grow, but intertwine with each other; the mass formed by them, in the smallest detail, reproduces the form in which hardening occurs. The chemistry of the process taking place at this time is the opposite of what is happening during cooking: alabaster turns into gypsum. Therefore, the casting is plaster, the mask is plaster, the bandage is also plaster, and they are made of alabaster.

Glauber's salt

Salt Na 2 SO 4 10H 2 O, discovered by the largest German chemist of the 17th century. Johann Rudolf Glauber and named after him, is still widely used in medicine, glassmaking, and crystallographic studies. Glauber described it this way: “This salt, if well cooked, has the appearance of ice; it forms long, perfectly transparent crystals, which melt on the tongue like ice. It has the taste of ordinary salt, without any causticity. Thrown on blazing coals, it does not crack with a noise, like common kitchen salt, and does not ignite with an explosion, like saltpeter. It is odorless and tolerates any degree of heat. It can be used with benefit in medicine both externally and internally. It heals fresh wounds without irritating them. It is an excellent internal medicine: when dissolved in water and given to the sick, it cleanses the intestines.

The mineral Glauber's salt is called mirabilite (from the Latin "mirabilis" - amazing). The name comes from the name given by Glauber to the salt he discovered; he called her wonderful. The world's largest developments of this substance are in our country, the water of the famous Kara-Bogaz-Gol Bay is extremely rich in Glauber's salt. The bottom of the bay is literally strewn with it.

Sulfites, sulfates, thiosulfates...

If you are an amateur photographer, you need a fixer, i.e. sodium salt of sulfurous (thiosulfuric) acid H 2 S 2 O 3. Sodium thiosulfate Na 2 S 2 O 3 (aka hyposulfite) served as a chlorine absorber in the first gas masks.

If you cut yourself while shaving, you can stop the blood with a crystal of potassium alum KAl (SO 4) 2 12H 2 O.

Whether you want to whitewash ceilings, cover an item with copper, or kill pests in your garden, dark blue crystals of CuSO 4 5H 2 O copper sulphate are indispensable.

The paper on which this book is printed is made with calcium hydrosulfite Ca(HSO 3) 2 .

Ferrous sulfate FeSO 4 7H 2 O, chromic alum K 2 SO 4 Cr 2 (SO 4) 3 2H 2 O and many other salts of sulfuric, sulfurous and thiosulfuric acids are also widely used.

Cinnabar

If mercury is spilled in the laboratory (there is a danger of poisoning with mercury vapor!), It is first collected, and those places from which silvery drops are not removed are covered with powdered sulfur. Mercury and sulfur react even in the solid state - with simple contact. A brick-red cinnabar is formed - mercury sulfide - a chemically extremely inert and harmless substance.

It is not difficult to isolate mercury from cinnabar. Many other metals, iron in particular, displace mercury from cinnabar.

Sulfur bacteria

In nature, the sulfur cycle gradually occurs, similar to the cycle of nitrogen or carbon. Plants consume sulfur - after all, its atoms are part of the protein. Plants take sulfur from soluble sulfates, and putrefactive bacteria convert protein sulfur into hydrogen sulfide (hence the disgusting smell of decay).

But there are so-called sulfur bacteria that do not need organic food at all. They feed on hydrogen sulfide, and in their bodies, as a result of the reaction between H 2 S, CO 2 and O 2, carbohydrates and elemental sulfur are formed. Sulfur bacteria often turn out to be full of sulfur grains - almost their entire mass is sulfur with a very small “additive” of organic substances.

Sulfur for pharmacists

All sulfa drugs - sulfidine, sulfazol, norsulfazol, sulgin, sulfodimesin, streptocid and others inhibit the activity of numerous microbes. And all these medicines are organic sulfur compounds. Here are the structural formulas of some of them:

After the advent of antibiotics, the role of sulfa drugs has somewhat decreased. However, many antibiotics can be considered as organic derivatives of sulfur. In particular, it is necessarily part of penicillin.

Fine elemental sulfur is the basis of ointments used in the treatment of fungal skin diseases.

Sulfur nitride conducts current

In 1975, Chemical and Engineering News reported the discovery of a new inorganic polymer that has many of the properties of a metal. Polymeric sulfur nitride - polythiazyl (SN) n it is easily pressed and forged, its electrical conductivity is close to that of mercury. At the same time, polythiazyl films do not equally conduct current in the longitudinal and transverse directions. This is explained by the fact that the film is built from ordered polymer fibers arranged parallel to each other.

What can be built from sulfur

In the 70s, in some countries of the world, the production of sulfur exceeded the demand for it. Therefore, sulfur began to look for new applications, primarily in such material-intensive areas as construction. As a result of these searches, sulfur foam appeared as a heat-insulating material, concrete mixtures in which Portland cement was partially or completely replaced by sulfur, and highway pavements containing elemental sulfur.

Sulfur (lat. Sulfur) S, a chemical element of the VI group of the periodic system of Mendeleev; atomic number 16, atomic mass 32.06. Natural Sulfur consists of four stable isotopes: 32S (95.02%), 33S (0.75%), 34S (4.21%), 36S (0.02%). Artificial radioactive isotopes 31S (T½ = 2.4 sec), 35S (T½ = 87.1 days), 37S (T½ = 5.04 min) and others have also been obtained.

Sulfur is a very common chemical element; occurs in the free state (native sulfur) and in the form of compounds - sulfides, polysulfides, sulfates. The water of the seas and oceans contains sulfates of sodium, magnesium, calcium. More than 200 sulfur minerals are known. Over 150 minerals are formed in the biosphere. The processes of oxidation of sulfides to sulfates, which in turn are reduced to secondary H2S and sulfides, are widespread. These reactions occur with the participation of microorganisms. Many processes in the biosphere lead to the concentration of Sulfur - it accumulates in the humus of soils, coals, oil, seas and oceans (8.9 10-2%), underground waters, lakes and salt marshes. Sulfur cycles in the biosphere: it is brought to the continents with precipitation and returned to the ocean with runoff.

Sulfur is a solid crystalline substance, stable in the form of two allotropic modifications. Rhombic α-S, lemon yellow, density 2.07 g/cm3, mp 112.8°C, stable below 95.6°C; monoclinic β-S, honey yellow, density 1.96 g/cm3, mp 119.3°C, stable between 95.6°C and melting point. Both of these forms are formed by eight-membered cyclic molecules S8 with energy S-S connections 225.7 kJ/mol.

Sulfur is a poor conductor of heat and electricity. It is practically insoluble in water, readily soluble in anhydrous ammonia, carbon disulfide and a number of organic solvents (phenol, benzene, dichloroethane, and others).

The configuration of the outer electrons of the S atom is 3s23p4. In compounds, Sulfur exhibits oxidation states -2, +4, +6. Sulfur is chemically active and combines especially easily with almost all elements when heated, with the exception of N2, I2, Au, Pt and inert gases. C O 2 in air above 300 ° C forms oxides: SO2 - sulfurous anhydride and SO3 - sulfuric anhydride, from which sulfurous acid and sulfuric acid, as well as their salts sulfites and sulfates.

When heated, sulfur interacts with metals, forming the corresponding sulfur compounds (sulfides) and polysulfur metals (polysulfides). At a temperature of 800-900 °C, sulfur vapor reacts with carbon, forming carbon disulfide CS2. Sulfur compounds with nitrogen (N4S4 and N2S5) can only be obtained indirectly.

In air, sulfur burns, forming sulfur dioxide - a colorless gas with a pungent odor:

The reducing properties of sulfur are manifested in the reactions of sulfur with other non-metals, however, at room temperature, sulfur reacts only with fluorine:

The sulfur melt reacts with chlorine, and the formation of two lower chlorides (sulfur dichloride and dithiodichloride) is possible:

With an excess of sulfur, various polysulfur dichlorides of the SnCl2 type are also formed.

When heated, sulfur also reacts with phosphorus, forming a mixture of phosphorus sulfides, among which is the higher sulfide P2S5:

In addition, when heated, sulfur reacts with hydrogen, carbon, silicon:

(hydrogen sulfide)

(carbon disulfide)

When heated, sulfur interacts with many metals, often very violently. Sometimes a mixture of metal with sulfur ignites when ignited. In this interaction, sulfides are formed:

Solutions of alkali metal sulfides react with sulfur to form polysulfides:

Of the complex substances, first of all, the reaction of sulfur with molten alkali should be noted, in which sulfur disproportionates similarly to chlorine:

The resulting alloy is called sulfur liver.

Sulfur reacts with concentrated oxidizing acids (HNO3, H2SO4) only during prolonged heating:

With an increase in temperature in sulfur vapor, changes occur in the quantitative molecular composition. The number of atoms in a molecule decreases:

At 800-1400 °C, vapors consist mainly of diatomic sulfur:

And at 1700 ° C, sulfur becomes atomic:

Sulfur is obtained from native sulfur, as well as by the oxidation of hydrogen sulfide and the reduction of sulfur dioxide. The source of hydrogen sulfide for the production of Sulfur is coke, natural gases, oil cracking gases. Numerous methods for processing H2S have been developed; highest value have the following: 1) H2S is extracted from gases with a solution of sodium monohydrothioarsenate:

Na2HAsS2O2 + H2S = Na2HAsS3O + H2O.

Then, by blowing air through the solution, sulfur is precipitated in free form:

NaHAsS3O + ½O2 = Na2HAsS2O2 + S.

2) H2S is isolated from gases in a concentrated form. Then its bulk is oxidized by atmospheric oxygen to Sulfur and partially to SO2. After cooling, H2S and the resulting gases (SO2, N2, CO2) enter two successive converters, where, in the presence of a catalyst (activated bauxite or specially manufactured aluminum gel), the following reaction occurs:

2H2S + SO2 = 3S + 2H2O.

The production of sulfur from SO2 is based on the reaction of its reduction with coal or natural hydrocarbon gases. Sometimes this production is combined with the processing of pyrite ores.