The creation of a centralized Russian state is brief. Formation of a centralized state

Sulfur is a chemical element located in the periodic table of Mendeleev at number 16 and is designated by the symbol S (from the Latin sulfur). The elemental nature of sulfur was established in 1777 by the French scientist and chemist Antoine Lavoisier. Sulfur boils at a temperature of 444 degrees Celsius. When melting, it passes from a solid to a liquid state, gradually changing its color, depending on the gradation of the melting temperature. For example, reaching 160 degrees Celsius, this chemical element changes its color from yellow to brown, and when heated to 190 degrees, the color changes to dark brown. Reaching a temperature of 190 degrees, sulfur loses its structure viscosity, gradually becoming more liquid. The element finally becomes fluid when it is heated to 300 degrees.

In addition to the ability to transform from solid to liquid, sulfur has a number of other interesting features. So, it has negative thermal conductivity and does not conduct electric current at all. It is absolutely insoluble in water, but is perfectly soluble in liquids that do not have water molecules in their structure (for example, ammonia). Interacts well with solvents and carbon disulfide, which are characterized by organic nature. Also, to the description of sulfur you can add its chemical zest. By its nature, sulfur is active and can easily enter into a chemical reaction when heated with any chemical element. May interact with substances such as:

• – at room temperature, reacts with it;
• with metals – creates sulfides and is at the same time an oxidizing agent;
• oxygen - heating to a temperature of 280 degrees Celsius, forms oxide compounds;
• fluorine - in tandem with this substance, sulfur shows itself as a reducing agent;
• phosphorus or carbon - in the absence of air supply, sulfur shows itself as an oxidizing agent.

Historical information

The chemical element sulfur in its native state or in the form of sulfur compounds was known to mankind many thousands of years ago. Its unique properties are mentioned not only on the sacred pages of the Bible and Torah, but in the poems of Homer and other sources. Due to its properties, sulfur was used in all kinds of ritual and religious ceremonies. Sulfur was one of the important components of “sacred” incense, which was used both to expel spirits and to summon them. It was used to “stupefy those who came”, using sulfur in combination with mercury; ancient shamans believed that in a burning state it was able to repel and expel demons, spirits and other evil spirits.

Sulfur became an integral part in the creation and use of “Greek fire”, used in the creation of incendiary mixtures for military purposes. In China, around the 8th century, sulfur was used as a pyrotechnic, its exact formula was banned, and its distribution was punishable by death.

There was an opinion that sulfur (as the beginning of flammability) and mercury (as a symbol of the beginning of metallicity) are the main components of all metals. Such a hypothesis took place in Arab alchemy.

In addition, Sera treated skin diseases for a long time, considering this method the most effective in medicine.

Application of sulfur

The scope of application of sulfur is quite multifaceted and diverse. Primarily, sulfur is used in the chemical industry to create sulfuric acid; in agriculture (to create products that help in the fight against pests and plant diseases, mainly grapes and cotton). Sulfur has also found its application in the production of rubber; it is used in the manufacture of matches, and is part of dyes and luminescent compounds. In medicine, sulfur is used in mud baths; so-called balneotherapy (from the Latin “to soak in water”) - helps in the treatment of arthritis and skin diseases. It has not been scientifically proven, but sulfur is also used to treat asthma, although many scientists believe that it is sulfur vapor that can provoke the appearance of respiratory diseases.

Sulfur in food

Products rich in sulfur include:

• gooseberry,
• grape,
• bakery products,
• garlic,
• asparagus,
• cabbage,
• lean beef,
• chicken eggs,
• dairy products,
• cereals, etc.

Lack of sulfur in the body

Lack of sulfur in the human body (with a daily intake of 4-6 mg) manifests itself in the form of diseases such as:

• hair loss or complete baldness,
• kidney disease,
• various allergies,
• dullness and brittleness of hair,
• joint pain,
• constipation,
• brittle nails,
• tachycardia.

Interesting and educational facts about sulfur

Sulfur is an essential element in the human body, as it takes part in the structure of cells, cartilage tissue, and nerve fibers. Also participates in metabolic processes. Shows itself as an excellent stabilizer of the work and coordination of the nervous system. Sulfur balances blood sugar levels, which is very useful for people suffering from diabetes.

Sulfur reduces pain in joints and cartilage, helps remove bile. It also has an anti-inflammatory effect on the body and is used for tissue regeneration. Helps strengthen muscle tissue of a growing body.

Sulfur itself is odorless, but when combined with other components it gives off the smell of rotten eggs.

As we can see, such unnoticeable and ordinary at first glance sulfur is an indispensable component in a full-fledged human life due to its wide range of applications. Without sulfur, our life would lose its benefits, our health would not be so strong.

Sulfur (S) is a non-metal belonging to the chalcogen group. The structure of the sulfur atom can be easily determined by referring to the periodic table of Mendeleev.

Structure

Sulfur in the periodic table is number 16 in the third period, group VI. The relative atomic mass of the element is 32.

Rice. 1. Position in the periodic table.

Natural sulfur has several isotopes:

• 32 S;
• 33 S;
• 34 S;
• 36 S.

In addition, 20 radioactive isotopes were artificially obtained.

Sulfur is an element of the p-family. The sulfur atom includes a nucleus with a positive charge of +16 (16 protons, 16 neurons) and 16 electrons located in three electron shells. The outer energy level contains 6 electrons, which determine the valency of the element. Two electrons are missing before the outer p-level is completed, which determines the oxidation state of sulfur as -2.

A sulfur atom can go into an excited state due to vacant 3d orbitals (five d orbitals in total). Therefore, an atom can exhibit oxidation states of +4 and +6.

Rice. 2. The structure of the atom.

Sulfur exhibits a negative oxidation state in the composition of salts - Al 2 S 3, SiS 2, Na 2 S. The fourth oxidation state is manifested in reactions with halogens (SCl 4, SBr 4, SF 4) and when interacting with oxygen (SO 2). The highest oxidation state (+6) occurs with the most electronegative elements - H 2 SO 4, SF 6, SO 3.

The electronic structure of the sulfur atom is 1s 2 2s 2 2p 6 3s 2 3p 4 or +16 S) 2) 8) 6.

Physical properties

Sulfur is a crystalline compound that, when heated, takes on a plastic form. The color of the non-metal varies from bright yellow to brown. Sulfur modifications depend on the number of sulfur atoms in the molecule.

Rice. 3. Sulfur.

Sulfur is a weak conductor of heat and electric current. Does not interact with water, but dissolves well in organic solvents - phenol, benzene, ammonia, carbon disulfide.

In nature, sulfur is found in the form of nuggets and in ores, minerals, and rocks. Sulfur is found in sulfides, sulfates, coal, oil, and gas. Sulfur is accumulated by bacteria that process hydrogen sulfide.

Chemical properties

Sulfur is an active element that reacts when heated with almost all elements, except inert gases and N 2, I 2, Au, Pt. Sulfur does not react with hydrochloric acid. The main reactions of sulfur with elements are described in the table.

Interaction	Reaction products	Example
With metals	Sulfides
With oxygen at 280°C	Sulfur oxide	S + O 2 → SO 2; 2S + 3O 2 → 2SO 3
With hydrogen when heated	Hydrogen sulfide	H 2 + S → H 2 S
With phosphorus when heated in the absence of air	Phosphorus sulfide	2P + 3S → P 2 S 3
	Sulfur fluoride	S + 3F 2 → SF 6
With carbon	Carbon disulfide
With acids		S + 2HNO 3 → 2NO + H 2 SO 4
With alkali	Sulfides and sulfites	3S + 6KOH → K 2 SO 3 + 2K 2 S + 3H 2 O

Sulfur is part of proteins. A large amount of sulfur accumulates in the hair.

What have we learned?

Sulfur is a yellow crystalline non-metal. Atomic structure diagram - +16 S) 2) 8) 6. Exhibits three oxidation states: -2, +4, +6. There are 24 known isotopes of sulfur. It is an active element that reacts with metals and non-metals. Forms salts - sulfites and sulfides, as well as sulfuric acid. Sulfur is insoluble in water and hydrochloric acid. Part of living organisms. In nature it is found in free and bound form.

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Chalcogens are a group of elements to which sulfur belongs. Its chemical symbol is S, the first letter of the Latin name Sulfur. The composition of a simple substance is written using this symbol without an index. Let's consider the main points concerning the structure, properties, production and use of this element. The characteristics of sulfur will be presented in as much detail as possible.

General characteristics and differences of chalcogens

Sulfur belongs to the oxygen subgroup. This is the 16th group in the modern long-period form of the periodic system (PS). The outdated version of the number and index is VIA. Names of chemical elements of the group, chemical symbols:

• oxygen (O);
• sulfur (S);
• selenium (Se);
• tellurium (Te);
• polonium (Po).

The outer electronic shell of the above elements has the same structure. In total, it contains 6 which can participate in the formation of chemical bonds with other atoms. Hydrogen compounds correspond to the composition H 2 R, for example, H 2 S is hydrogen sulfide. Names of chemical elements that form two types of compounds with oxygen: sulfur, selenium and tellurium. The general formulas of the oxides of these elements are RO 2, RO 3.

Chalcogens correspond to simple substances that differ significantly in physical properties. The most common chalcogens in the earth's crust are oxygen and sulfur. The first element forms two gases, the second - solids. Polonium, a radioactive element, is rarely found in the earth's crust. In the group from oxygen to polonium, non-metallic properties decrease and metallic properties increase. For example, sulfur is a typical non-metal, while tellurium has a metallic luster and electrical conductivity.

Element No. 16 of the periodic table D.I. Mendeleev

The relative atomic mass of sulfur is 32.064. Of the natural isotopes, 32 S is the most common (more than 95% by weight). Nuclides with atomic masses 33, 34 and 36 are found in smaller quantities. Characteristics of sulfur by position in the PS and atomic structure:

• serial number - 16;
• the charge of the atomic nucleus is +16;
• atomic radius - 0.104 nm;
• ionization energy -10.36 eV;
• relative electronegativity - 2.6;
• oxidation state in compounds - +6, +4, +2, -2;
• valency - II(-), II(+), IV(+), VI (+).

Sulfur is in the third period; electrons in an atom are located at three energy levels: on the first - 2, on the second - 8, on the third - 6. All external electrons are valence. When interacting with more electronegative elements, sulfur gives up 4 or 6 electrons, acquiring typical oxidation states of +6, +4. In reactions with hydrogen and metals, the atom attracts the missing 2 electrons until the octet is filled and a stable state is achieved. in this case it is reduced to -2.

Physical properties of rhombic and monoclinic allotropic forms

Under normal conditions, sulfur atoms are connected to each other at an angle to form stable chains. They can be closed in rings, which suggests the existence of cyclic sulfur molecules. Their composition is reflected by the formulas S 6 and S 8.

The characteristics of sulfur should be supplemented by a description of the differences between allotropic modifications that have different physical properties.

Rhombic, or α-sulfur, is the most stable crystalline form. These are bright yellow crystals consisting of S 8 molecules. The density of rhombic sulfur is 2.07 g/cm3. Light yellow monoclinic crystals are formed by β-sulfur with a density of 1.96 g/cm3. The boiling point reaches 444.5°C.

Preparation of amorphous sulfur

What color is sulfur in its plastic state? It is a dark brown mass, completely different from the yellow powder or crystals. To obtain it, you need to melt orthorhombic or monoclinic sulfur. At temperatures above 110°C, a liquid is formed; with further heating it darkens, and at 200°C it becomes thick and viscous. If you quickly pour molten sulfur into cold water, it will solidify to form zigzag chains, the composition of which is reflected by the formula S n.

Sulfur solubility

Some modifications in carbon disulfide, benzene, toluene and liquid ammonia. If organic solutions are slowly cooled, needle-shaped crystals of monoclinic sulfur are formed. When liquids evaporate, transparent lemon-yellow crystals of rhombic sulfur are released. They are fragile and can be easily ground into powder. Sulfur does not dissolve in water. The crystals sink to the bottom of the vessel, and the powder may float on the surface (not wetted).

Chemical properties

The reactions exhibit the typical non-metallic properties of element No. 16:

• sulfur oxidizes metals and hydrogen and is reduced to the S 2- ion;
• combustion in air and oxygen produces sulfur di- and trioxide, which are acid anhydrides;
• in a reaction with another more electronegative element - fluorine - sulfur also loses its electrons (oxidizes).

Free sulfur in nature

In terms of abundance in the earth's crust, sulfur is in 15th place among the chemical elements. The average content of S atoms is 0.05% of the mass of the earth's crust.

What color is sulfur in nature (native)? It is a light yellow powder with a characteristic odor or yellow crystals with a glassy luster. Deposits in the form of placers, crystalline layers of sulfur are found in areas of ancient and modern volcanism: in Italy, Poland, Central Asia, Japan, Mexico, and the USA. Often, beautiful druses and giant single crystals are found during mining.

Hydrogen sulfide and oxides in nature

In areas of volcanism, gaseous sulfur compounds come to the surface. The Black Sea at a depth of over 200 m is lifeless due to the release of hydrogen sulfide H 2 S. The formula of sulfur oxide is divalent - SO 2, trivalent - SO 3. The listed gaseous compounds are present in some deposits of oil, gas, and natural waters. Sulfur is a component of coal. It is necessary for the construction of many organic compounds. When the whites of a chicken egg rot, hydrogen sulfide is released, which is why this gas is often said to have the smell of rotten eggs. Sulfur is a biogenic element; it is necessary for the growth and development of humans, animals and plants.

The importance of natural sulfides and sulfates

The characterization of sulfur will be incomplete if it is not said that the element is found not only in the form of simple substances and oxides. The most common natural compounds are salts of hydrogen sulfide and sulfuric acids. Sulfides of copper, iron, zinc, mercury, and lead are found in the minerals sphalerite, cinnabar and galena. Sulfates include sodium, calcium, barium and magnesium salts, which are formed in nature by minerals and rocks (mirabilite, gypsum, selenite, barite, kieserite, epsomite). All these compounds are used in various sectors of the economy, used as raw materials for industrial processing, fertilizers, and building materials. Some crystalline hydrates are of great medical importance.

Receipt

The yellow substance in a free state is found in nature at different depths. If necessary, sulfur is smelted from rocks, not by raising them to the surface, but by pumping superheated water into the depths. Another method involves sublimation from crushed rocks in special furnaces. Other methods involve dissolution with carbon disulfide or flotation.

Industry needs for sulfur are great, so its compounds are used to obtain the elemental substance. In hydrogen sulfide and sulfides, sulfur is in reduced form. The oxidation state of the element is -2. Sulfur is oxidized, increasing this value to 0. For example, according to the Leblanc method, sodium sulfate is reduced with coal to sulfide. Then calcium sulfide is obtained from it, treated with carbon dioxide and water vapor. The resulting hydrogen sulfide is oxidized with atmospheric oxygen in the presence of a catalyst: 2H 2 S + O 2 = 2H 2 O + 2S. Determination of sulfur obtained by different methods sometimes gives low purity values. Refining or purification is carried out by distillation, rectification, and treatment with mixtures of acids.

Application of sulfur in modern industry

Granulated sulfur is used for various production needs:

1. Production of sulfuric acid in the chemical industry.
2. Production of sulfites and sulfates.
3. Production of preparations for plant nutrition, combating diseases and pests of agricultural crops.
4. Sulfur-containing ores are processed at mining and chemical plants to produce non-ferrous metals. A related production is sulfuric acid production.
5. Introduction to the composition of certain types of steel to impart special properties.
6. Thanks they get rubber.
7. Production of matches, pyrotechnics, explosives.
8. Use for the preparation of paints, pigments, artificial fibers.
9. Bleaching of fabrics.

Toxicity of sulfur and its compounds

Dust particles with an unpleasant odor irritate the mucous membranes of the nasal cavity and respiratory tract, eyes, and skin. But the toxicity of elemental sulfur is not considered particularly high. Inhalation of hydrogen sulfide and dioxide can cause severe poisoning.

If during the roasting of sulfur-containing ores at metallurgical plants the exhaust gases are not captured, they enter the atmosphere. Combining with drops and water vapor, oxides of sulfur and nitrogen give rise to so-called acid rain.

Sulfur and its compounds in agriculture

Plants absorb sulfate ions along with the soil solution. A decrease in sulfur content leads to a slowdown in the metabolism of amino acids and proteins in green cells. Therefore, sulfates are used for fertilizing agricultural crops.

To disinfect poultry houses, basements, and vegetable stores, the simple substance is burned or the premises are treated with modern sulfur-containing preparations. Sulfur oxide has antimicrobial properties, which has long been used in the production of wines and in the storage of vegetables and fruits. Sulfur preparations are used as pesticides to combat diseases and pests of agricultural crops (powdery mildew and spider mites).

Application in medicine

The great ancient healers Avicenna and Paracelsus attached great importance to the study of the medicinal properties of yellow powder. Later it was found that a person who does not receive enough sulfur in food becomes weaker and experiences health problems (these include itching and flaking of the skin, weakening of hair and nails). The fact is that without sulfur, the synthesis of amino acids, keratin, and biochemical processes in the body is disrupted.

Medical sulfur is included in ointments for the treatment of skin diseases: acne, eczema, psoriasis, allergies, seborrhea. Baths with sulfur can relieve pain from rheumatism and gout. For better absorption by the body, water-soluble sulfur-containing preparations have been created. This is not a yellow powder, but a white, finely crystalline substance. When this compound is used externally, it is included in a cosmetic product for skin care.

Plaster has long been used to immobilize injured parts of the human body. prescribed as a laxative medicine. Magnesia lowers blood pressure, which is used in the treatment of hypertension.

Sulfur in history

Even in ancient times, a yellow non-metallic substance attracted human attention. But it was not until 1789 that the great chemist Lavoisier discovered that powders and crystals found in nature were composed of sulfur atoms. It was believed that the unpleasant odor produced by burning it repels all evil spirits. The formula of sulfur oxide, which is obtained during combustion, is SO 2 (dioxide). It is a toxic gas and inhaling it is hazardous to health. Scientists explain several cases of mass extinction of people by entire villages on the coasts and in the lowlands by the release of hydrogen sulfide or sulfur dioxide from the ground or water.

The invention of black powder increased military interest in yellow crystals. Many battles were won thanks to the ability of craftsmen to combine sulfur with other substances during the manufacturing process. The most important compound - sulfuric acid - was also learned to be used a very long time ago. In the Middle Ages, this substance was called oil of vitriol, and salts were called vitriol. Copper sulfate CuSO 4 and iron sulfate FeSO 4 have still not lost their importance in industry and agriculture.

	S	16			Sulfur
					t o kip. (o C)	444,674	Step oxide	-2 +4 +6
		32,066			t o float(o C)	119,3	Density	2070(a) 1960(b)
	3s 2 3p 4				OEO	2,60	in the ground bark	0,052 %

Sulfur is one of the few substances with which the first “chemists” operated several thousand years ago. She began to serve humanity long before she occupied the cell under the periodic table. № 16.

Many ancient 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 provide sufficient grounds for archaeological excavations in search of the remains of paradise or fiery hell, then their evidence that the ancients were familiar with sulfur and some of its properties can be taken on faith.

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

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

And now gunpowder production consumes part of the mined sulfur, albeit a very insignificant one. Nowadays, sulfur is one of the most important types of raw materials for many chemical industries. And this is the reason for the continuous increase in world sulfur production.

Origin of sulfur

Large accumulations of native sulfur are not very common. It is more often present in some ores. Native sulfur ore is a rock interspersed with pure sulfur.

When were these inclusions formed - simultaneously with the accompanying rocks or later? The direction of prospecting and exploration work depends on the answer to this question. But, despite thousands of years of communication with sulfur, humanity still does not have a clear answer. There are several theories whose authors 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 basins. Special bacteria reduced sulfates dissolved in water to hydrogen sulfide, which rose upward, entered the oxidation zone, and here, chemically or with the participation of other bacteria, was oxidized to elemental sulfur. The sulfur settled to the bottom, and subsequently the sulfur-containing silt formed ore.

The theory of epigenesis (sulfur inclusions formed later than the main rocks) has several options. The most common of them assumes that groundwater, penetrating through rock strata, 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, when oxidized, releases pure sulfur in the voids and cracks of rocks.

In recent decades, one of the varieties of the theory of epigenesis has found more and more confirmation - the theory of metasomatosis (translated from Greek “metasomatosis” means replacement). According to it, the transformation of gypsum CaSO4-H2O and anhydrite CaSO4 into sulfur and calcite CaCO3 constantly occurs in the depths. This theory was created in 1935 by Soviet scientists L. M. Miropolsky and B. P. Krotov. In particular, this fact speaks in its favor.

In 1961, the Mishrak field was discovered in Iraq. The sulfur here is contained in carbonate rocks, which form an arch supported by pillars going deep (in geology they are called wings). These wings consist 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 anhydrites 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 supporters of the theory of metasomatism additional arguments.

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 still lakes on earth (in particular, Sernoye Lake near Sernovodsk), where syngenetic deposition of sulfur occurs and the sulfur-bearing silt does not contain 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 of the complexity of the phenomena occurring in the depths. We all know from elementary school mathematics 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 precautions. Sulfur deposits are almost always accompanied by accumulations of poisonous gases - sulfur compounds. In addition, we must not forget about the possibility of spontaneous combustion.

Open pit mining of ore occurs like this. Walking excavators remove layers of rock under which ore lies. The ore layer is crushed by explosions, after which the ore blocks are sent to a processing plant, and from there to a sulfur smelter, where sulfur is extracted from the concentrate. Extraction methods are different. Some of them will be discussed below. Here it is appropriate to briefly describe the well 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, rich deposits of sulfur ore were discovered in the southern United States. But it was not easy to approach the layers: hydrogen sulfide leaked into the mines (namely, the mine was supposed to be developed by the mine method) and blocked access to the sulfur. In addition, sandy quicksand made it difficult to break through to the sulfur-bearing layers. The solution was found by the chemist Hermann Frasch, who proposed melting sulfur underground and pumping 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, the installation of Frasch is very simple: a pipe in a pipe. Superheated water is supplied into the space between the pipes and flows through it into the formation. And molten sulfur rises through the inner pipe, heated from all sides. The modern version of the Frasch installation is complemented by a third - the narrowest pipe. Through it, compressed air is supplied into the well, which helps raise the molten sulfur to the surface. One of the main advantages of the Frasch method is that it allows one to obtain relatively pure sulfur already at the first stage of production. This method is very effective when mining rich ores.

Previously, it was believed that the method of underground smelting of sulfur 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 popular Poland, large quantities of sulfur are already extracted by this method; in 1968, the first sulfur wells were launched in the USSR.

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

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

Thermal methods for extracting sulfur are the oldest. Back in the 18th century, in the Kingdom of Naples, sulfur was smelted in heaps called solfatares. Sulfur is still smelted in Italy in primitive furnaces - “calcarones”. The heat required to smelt sulfur from ore is obtained by burning part of the mined sulfur. This process is ineffective, losses reach 45%.

Italy also became the birthplace of steam-water methods for extracting sulfur from ores. In 1859, Giuseppe Gill received a patent for his device - the predecessor 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 steam is supplied there under pressure. The pulp is heated to 130° C. The sulfur contained in the concentrate melts and is separated from the rock. After a short settling, the melted sulfur is drained. The autoclave then releases the “tailings”—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 devices the height of a four-story building. Such autoclaves are installed, in particular, at the sulfur smelting plant of the Rozdol Mining and Chemical Plant in the Carpathian region.

In some industries, for example at a large sulfur plant in Tarnobrzeg (Poland), waste rock is separated from molten sulfur using special filters. The separation method using special centrifuges was recently developed in our country. In a word, “gold ore (more precisely, golden ore) can be separated from waste rock” in different ways.

Different countries satisfy their needs for sulfur in different ways. Mexico and the USA mainly use the Frasch method. Italy, which ranks third among capitalist states in sulfur production, continues to mine and process (different methods) sulfur ores from Sicilian deposits and the province of Marco. Japan has significant reserves of volcanic sulfur. France and Canada, which do not have native sulfur, have developed large-scale production of it from gases. England and Germany do not have their own sulfur deposits. They cover their needs for sulfuric acid by processing sulfur-containing raw materials (mainly pyrite), and import elemental sulfur.

Russia fully meets its needs thanks to its own sources of raw materials. After the discovery and development of the rich Carpathian deposits, the USSR and Poland significantly increased sulfur production. This industry continues to develop. New large enterprises were built in 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 into macromolecules

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

Since then, ideas about sulfur as an element have not changed very much, but have deepened and expanded significantly.

It is now known that element number 16 consists 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 type is rhombic sulfur (the most stable modification) - the crystals have the form of octahedra with cut corners. All other modifications turn into this modification at room (or close to room) temperature. It is known, for example, that during crystallization from rapmel (melting point of sulfur 119.5 ° C), needle-shaped crystals (monoclinic form) are first obtained. But this modification is unstable, and at temperatures below 95.6 ° C it becomes rhombic. A similar process occurs with other modifications of sulfur.

Let us recall a well-known experiment—the production of plastic sulfur.

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

The molecules of sulfur crystals always consist of eight atoms (S8), and the difference in the properties of sulfur modifications is explained by polymorphism - the unequal structure of the crystals. The atoms in the sulfur molecule are arranged in a closed cycle

S-S-S

S-S-S

During melting, the bonds in the cycle are broken, and cyclic molecules turn into linear ones.

The unusual behavior of sulfur during melting has been given different interpretations. One of them is this. At temperatures from 155 to 187°, there appears to be a significant increase in molecular weight, this is confirmed by a multiple increase in viscosity. At 187° C, the viscosity of the melt reaches almost a thousand poises, and an almost solid substance is obtained. A further increase in temperature leads to a decrease in viscosity (molecular weight drops). At 300° C, sulfur returns to a fluid state, and at 444.6° C it boils.

In sulfur vapor, with increasing temperature, the number of atoms in the molecule gradually decreases:

S8 -> S6 -> S4 -> S2. At 1700°C, sulfur vapor is monatomic.

Briefly about sulfur compounds

In terms of prevalence, element No. 16 ranks -15th. 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, in nature, sulfur is found not only in a free state, but also in the form of various inorganic compounds. Particularly common are sulfates (mainly alkali and alkaline earth metals) and sulfides ( iron, copper, zinc, lead).Sulfur is also found in coal, shale, oil, natural gases, in animal and plant organisms.

When sulfur interacts with metals, as a rule, quite a lot of heat is released. In reactions with oxygen, sulfur produces several oxides, the most important of which are SO2 and SO3 - the anhydrides of sulfurous acids H2SO3 and sulfuric acids H2SO4. A compound of sulfur with hydrogen - hydrogen sulfide H2S - is a very poisonous, foul-smelling gas, always present in places where organic residues rot. Earthly

the crust in places located near sulfur deposits often contains quite significant amounts of hydrogen sulfide. In aqueous solution, this gas has acidic properties. Its solutions cannot be stored in air; it oxidizes, releasing sulfur:

2H2S + O2 = 2H2O + 2S.

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

What is sulfur needed for?

Among the things around us, there are few for the production 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 consume about 14 kg of sulfur. It can be said without exaggeration that the industrial potential of a country is quite accurately determined by sulfur consumption.

A significant portion of the world's sulfur production is consumed by the paper industry (sulfur compounds help to separate cellulose). In order to produce one 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 pest control products. 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. 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 world's sulfur is used to produce sulfuric acid. To get one ton of H2SO4, 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.

Significant amounts of sulfur (and sulfuric acid) are consumed in the production of explosives and matches. Pure sulfur, freed from impurities, is needed for the production of dyes and luminous compounds.

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

The list of examples confirming the paramount importance of element No. 16 could be continued, but “one cannot comprehend the immensity.” Therefore, let’s briefly mention that sulfur is also necessary for such industries as mining, food, textiles, and let’s call it a day.

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Our century is considered the century of “exotic” materials - transuranium elements, titanium, semiconductors, and so on. But the seemingly unassuming, long-known element No. 16 continues to be absolutely necessary. It is estimated that 88 of the 150 most important chemical products use either sulfur itself or sulfur compounds in its production.