Sulfur ores are mined 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 toxic 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 vary. 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, sand floats made it difficult to break through to the sulfur-bearing layers. A 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 you to obtain relatively pure sulfur. 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 Poland, this method is already extracted a large number of sulfur: 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 - “solfatars”. 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 apparatus - 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 is melted and separated from the rock. After a short settling, the melted sulfur is drained. Then the “tailings” - a suspension of waste rock in water - are released from the autoclave. 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 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 using special filters. A method for separating sulfur and waste rock using centrifuges was developed in our country. In a word, “gold ore (more precisely, golden ore) can be separated from waste rock” in different ways.
Lately everything more attention is paid to borehole geotechnological methods of sulfur extraction. At the Yazovskoe 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 from the Institute of Mining Chemical Raw Materials have proposed a method for underground gasification of sulfur. In this method, sulfur is set on fire in the formation, and sulfur dioxide is pumped to the surface, which is used to produce sulfuric acid and other useful products.
They satisfy their sulfur needs in different ways different countries. Mexico and the USA mainly use the Frasch method. Italy, which ranks third in sulfur production capitalist states, continues to mine and process ( different methods) sulfur ores of the Sicilian deposits and the province of Marche. Japan has significant reserves of volcanic sulfur. France and Canada, which do not have native sulfur, have developed large-scale production from gases. Both 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 from other countries.
The Soviet Union and 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 sulfur production. This industry continues to develop. IN last years 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.
Sulfur- a lemon-yellow mineral, sometimes honey-yellow, yellowish-gray or brownish, is molecular sulfur - S, the mineral is very brittle, hardness 1-2.
Inclusions of organic matter and oil droplets can give crystals a brown or black color.
Crystallizes in the rhombic system. It occurs in the form of pyramidal crystals and in granular aggregates. Sometimes sintered kidney-shaped forms and deposits and earthy masses are observed.
The shine is diamond-like, greasy at the fracture, and translucent in the crystals. Native sulfur is sensitive to elevated temperatures and cracks even from the warmth of your hands. With a match it easily melts and lights up with a blue flame.
Name
Origin Latin word sulfur unknown. Russian name The element is usually derived from the Sanskrit "sira" - light yellow. There may be a relationship between “sulphur” and the Hebrew “seraphim” - plural. number from “seraph” - literally “burning”, and sulfur burns well. In Old Russian and Old Church Slavonic, “sulfur” is generally any flammable substance, including fat.
Origin
Sulfur is formed exclusively on the surface of the earth's crust, as a result of volcanic eruptions, precipitating in the form of sublimates, and sometimes pouring out in molten form. It is formed during the weathering of sulfides (mainly pyrite), or accumulates in marine sediments, oils and bitumen, biochemically. Can be associated with gypsum, standing out from its thickness. Large accumulations of native sulfur are quite rare in nature. More often it is present in the host rock in the form of small inclusions.
Place of Birth
Sulfur deposits are widespread in Central Asia, the Gaurdak and Shor-Su deposits are found in cracks and voids of various sedimentary rocks in association with oil, gypsum,
celestine, calcite, aragonite, etc. In the Kara-Kum desert in the form of mounds covered with siliceous crusts, in association with gypsum, quartz, chalcedony, opal, etc. Large sedimentary deposits
are available in the Volga region (near the city of Kuibyshev). The deposits of Sicily, powerful deposits in the states of Texas and Louisiana (USA), Bolivia, Mishrak and Iraq, Southern Poland, and Stassfurt in Germany are very famous. Areas of volcanism: Kamchatka, Japan, Italy, Indonesia.
Application
The main use of sulfur is in the production of sulfuric acid, used in many industries; used in agriculture for pest control, in rubber production (rubber vulcanization process), in the manufacture of matches, paints, and pyrotechnics.
Healing and magical properties
It is believed that sulfur has the ability to absorb negative energy, helps avoid conflicts and quarrels, and pacifies emotional impulses.
A significant part of natural healing methods is based on the use of sulfur compounds, be it a clove of garlic or a Matsesta hydrogen sulfide bath. Polysulfides - compounds of sulfur and hydrogen sulfide - are responsible for the healing effect here.
Sulfur has long been known to man. Evidence of its use in Egypt dates back to the second millennium BC. e. Both the ancient Greeks and Romans knew sulfur. She is mentioned in famous works Homer, Pliny the Elder and in the Bible. Sulfur has been widely used in medicine for a long time. Since ancient times it has been used for medicinal purposes in Rus'. One of the first domestic scientists who studied sulfur, M.V. Lomonosov wrote: “The earth in its depths contains such an amount of sulfur that not only are the underground filled with it... but this fossil stands out even on the surface of the earth,” noting at the same time that it occurs “it is native and pure, but rarely.” Somewhat later, Academician V. Severgin assessed the distribution of sulfur more optimistically: “Native sulfur is pure and mixed with lands in Russia in abundance.” Nowadays, over 400 minerals containing sulfur are known. And its content is earth's crust is about 0.05%.
The presence of native sulfur in Crimea was indicated in the middle of the last century. The Mining Journal wrote about the “search” for sulfur here in 1849. It was about the vicinity of Lake Chokrak on the Kerch Peninsula, where “very clear, but very small crystals of native sulfur” were discovered in the limestone. Lieutenant Antipov carried out exploration work here by order of Prince Vorontsov with the excavation of mine workings. It turned out that sulfur is confined only to the outlets of hydrogen sulfide sources. Its formation was explained by the decomposition of hydrogen sulfide. “In conclusion, I must say,” writes the lieutenant, “that this sulfur deposit is not of any technical importance, except for one healing property of the sources, which promise great benefits.” Thin whitish deposits of sulfur can still be observed at the Chokrak and other sources of hydrogen sulfide waters, for example, in the vicinity of Sudak.
Native sulfur is often formed during the weathering of sulfides - pyrite and marcasite. It was found in Crimea in connection with various rocks: in marls near Feodosia, limestones in the vicinity of Bakhchisarai, granodiorites near Alushta. Sulfur of this type is usually included in the composition of earthy aggregates mixed with iron sulfates and hydroxyls and is represented by tiny irregular grains, sometimes crystals. It is often accompanied by plaster. Fine powdery sulfur is present in the silts of salt lakes, for example, Saki.
The largest accumulations of sulfur were discovered in Crimea in 1883 by N.I. Andrusov on the Kerch Peninsula near the village of Chekur-Koyash. Later it turned out that there was a whole deposit here. Sulfur is confined to gypsum-bearing clays and marls and forms layers and nodules ranging in size from several millimeters to 30 cm. Its content in ore ranges from 10 to 30%.
According to one of the accepted hypotheses, native sulfur was formed from gypsum under the influence of hydrogen sulfide waters enriched with organic substances with the participation of bacteria.
By today's scale, the deposit would look modest. But at one time it played an important role. The fact is that before the revolution, sulfur was imported into Russia from abroad. And the Chekur-Koyashskoye deposit was one of the first to produce industrial domestic sulfur. Here Short story its development.
In the last century, only a little sulfur was extracted by artisanal methods for local needs. The deposit has hardly been studied. In 1906, a Belgian company leased it and began geological exploration and preparation for exploitation. The technical level of the work was low. The workings were poorly ventilated. This led to tragic death a worker and an administrator were poisoned by sulfur gas at the mine face, after which work was stopped.
Since the beginning of the First World War, a critical situation with sulfur developed in the country, and by decision of the Military-Industrial Committee, exploration of Chekur-Koyash began in 1915. In 1916, preparations for development and associated production were already underway. 1600 tons of ore were extracted. About 10 tons of sulfur were manually selected from it. But in 1917, work was stopped and the mines were flooded with water.
The revival of the mine began from the time of establishment Soviet power in Crimea. At first, a small amount of sulfur was obtained from small factory from previously mined ore. Then they carried out a thorough geological exploration and calculation of sulfur reserves. In 1928, the mine and plant, which were practically built anew, began to produce sulfur. Mining lasted for about 10 years, and the deposit was depleted. Crimean sulfur in initial period mining played an important role. “Kerch sulfur is of great importance for the Union of our republics,” noted the press in the 30s. With the discovery and development of large deposits in Central Asia, Chekur-Koyasha sulfur retained only local significance. Currently, about a dozen non-industrial manifestations of sulfur are known on the Kerch Peninsula.
The appearance of native sulfur is peculiar. Yellow color different shades, often straw yellow. The shine is greasy. Sulfur forms films, earthy and powdery masses, thin layers and nodules, and is less common in regular crystals. Characteristic are tetrahedral bipyramids with truncated apices of the most common rhombic, or so-called alpha, sulfur. It is most stable on the surface of the earth. It is curious that in the limestones of the area Kerch Strait S.P. Popov discovered in 1901, along with this variety, lamellar crystals of monoclinic (beta) sulfur, which are rarer in nature. This is the world's first discovery of beta sulfur in earth's surface unrelated to volcanic activity. The form of beta-sulfur crystals from the Crimea but S.P. Popov is firmly included in reference books on mineralogy.
In terms of hardness, sulfur is slightly superior to talc, the softest mineral on the Mohs scale. Talc has a hardness of 1, while sulfur has a hardness of 1-2 on this scale. Sulfur is twice as heavy as water. Its density is about two. An important difference is the ability of sulfur to burn. According to Pliny the Elder, “no substance ignites so easily, from which it is clear that it contains great fiery power.” Before the advent of modern ideas for a long time It was believed that sulfur was a carrier of a special flammable substance. The ability of sulfur to burn can be used as a reliable diagnostic sign. An insignificant grain of the substance is enough to test. The test can be carried out on the tip of a penknife blade using a burning match or spirit lamp. You can also use a hot sewing needle. The smell of burning sulfur is also very characteristic, distinguishing it from other minerals. In fine powdery and earthy secretions, sulfur is similar to iron sulfates. Unlike many similar minerals, sulfur dissolves in kerosene and turpentine.
Native sulfur often contains up to several percent of impurities. Crimean sulfur contains calcium, selenium, arsenic and some other elements. Impurities may limit the use of sulfur in certain industries.
Sulfur has an extremely large number of professions, and has been for a long time. “Its benefits are very extensive,” V. Severgin wrote at the beginning of the last century. “It is used in various ways in chemistry, in the art of medicine, for the extraction of sulfuric acid, for the preparation of cinnabar, gunpowder, in amusing fires... for the extermination of insects.” . Currently, sulfur is still found greater application. Every year, tens of millions of tons of native sulfur are mined around the world. It is used in the production of synthetic fibers, rubber, dyes, and in the food industry. Approximately half of the mined sulfur is used to produce sulfuric acid, a quarter to the pulp and paper industry, and about 10% to agriculture. Crimean sulfur was used mainly to control vineyard pests and for sanitary purposes.
Today it is the chemical industry that consumes greatest number sulfur. The most important is sulfuric acid. That is why almost half of the sulfur that is mined around the world is spent on its production. When burned, three hundred kg of sulfur produces about one ton of sulfuric acid.
Another industry that is inextricably linked with mined sulfur and consumes a significant part of it is paper production. To obtain 17 cellulose, you need to use at least one hundred kg of sulfur.
Use of sulfur in the rubber industry
Sulfur is most often used to turn rubber into rubber. When mixed with sulfur and heated to the required temperature, rubber acquires properties for which it is highly valued among consumers - elasticity and elasticity. This process is also called vulcanization.
It happens:
- Hot. Proposed by Goodyear in 1839. The mixture of rubber and sulfur is heated to approximately 150 degrees Celsius.
- Cold. Proposed by Parkes in 1846. The rubber is not heated, but treated with a solution of sulfur chloride S2C12.
Vulcanization is carried out in order to create bonds between polymer groups in the substance.
Most of the important physical and mechanical properties of a material that has undergone vulcanization depend on what it is made of, how it is distributed and how much energy the -C-Sn-C- bonds contain. For example, with different concentrations of added sulfur, completely different materials with different properties can be obtained.
Sulfur in agriculture and medicine
Sulfur in its pure form and in combination with other elements is successfully used for agricultural purposes. It is as important for plants as phosphorus. Fertilizers containing sulfur have a positive effect on both the quality of the harvest and its quantity.
Experimentally, scientists have identified the effect of sulfur on the resistance of cereals to frost. It provokes the formation of organic substances that contain sulfhydryl groups-S-H. Thanks to this, the frost resistance of the plant increases due to the hydrophilicity of proteins and changes in the internal structure. Another way sulfur can be used for agricultural purposes is in the prevention of diseases, mainly in cotton and grapes.
Pure sulfur, as well as its compounds with other elements, can be used for medical purposes. The basis for many ointments that are used to treat various fungal skin diseases is fine sulfur. Most drugs of the sulfa group are nothing more than compounds different substances with sulfur: sulfadimezin, norsulfazole, white streptocide.
Today the volume of sulfur production exceeds required amount raw materials for industry. It is extracted not only from the depths of the earth, but also from gases or during fuel purification. In this regard, new ways of using the substance are being invented, for example, in construction. Thus, in Canada they invented sulfur foam, which is planned to be used in laying roads and for laying a pipeline outside the Arctic Circle. And in Montreal, the world's first house was built from blocks of unusual composition, which consist of a third of sulfur (the rest is sand). To make such blocks, metal molds are used, in which the mixture is heated to a temperature of more than 100 degrees Celsius. They are as durable and wear-resistant as their cement counterparts. A simple treatment with synthetic varnish will help avoid oxidation. From such blocks you can build a garage or a warehouse, a store or a house.
Today, you can increasingly find information about the emergence of new building materials that contain sulfur. It's no longer a secret that when using sulfur, an asphalt coating with excellent properties is obtained. It can compare to and even surpass gravel surfaces. It is quite profitable to use it in the construction of a highway. To obtain this composition, you need to mix one part of asphalt, two parts of sulfur and 13 parts of sand.
The demand for this raw material is growing. Sulfur sales will only increase in the long term.
Section 1. Determination of sulfur.
Section 2. Natural minerals sulfur.
Section 3. History of discoverysulfur.
Section 4. Origin of the name sulfur.
Section 5. Origin of sulfur.
Section 6. Receiptsulfur.
Section 7. Manufacturerssulfur.
Section 8. Propertiessulfur.
- Subsection 1. Physicalproperties.
- Subsection2. Chemicalproperties.
Section 10. Fire hazardous properties of sulfur.
- Subsection1. Fires in sulfur warehouses.
Section 11. Being in nature.
Section 12. Biological rolesulfur.
Section 13. Applicationsulfur.
Definitionsulfur
sulfur is element of the sixth group of the third period of the periodic table of chemical elements of D.I. Mendeleev, with atomic number 16. Exhibits non-metallic properties. Denoted by the symbol S (Latin Sulfur). In hydrogen and oxygen compounds is found in various ions and forms many acids and salts. Many sulfur-containing salts are poorly soluble in water.
Sulfur - S, chemical element with atomic number 16, atomic mass 32.066. Chemical symbol sulfur S is pronounced "es". Natural sulfur consists of four stable nuclides: 32S (content 95.084% by weight), 33S (0.74%), 34S (4.16%) and 36S (0.016%). The radius of the sulfur atom is 0.104 nm. Ion radii: S2- ion 0.170 nm (coordination number 6), S4+ ion 0.051 nm (coordination number 6) and S6+ ion 0.026 nm (coordination number 4). The sequential ionization energies of the neutral sulfur atom from S0 to S6+ are, respectively, 10.36, 23.35, 34.8, 47.3, 72.5 and 88.0 eV. Sulfur is located in the VIA group of D.I. Mendeleev’s periodic table, in the 3rd period, and belongs to the chalcogens. The configuration of the outer electronic layer is 3s23p4. The most characteristic oxidation states in compounds are -2, +4, +6 (valency II, IV and VI, respectively). The Pauling electronegativity value of sulfur is 2.6. Sulfur is a non-metal.
In its free form, sulfur appears as yellow, brittle crystals or yellow powder.
Sulfur is
Natural minerals sulfur
Sulfur is the sixteenth most abundant element in the earth's crust. It is found in a free (native) state and bound form.
The most important natural sulfur compounds: FeS2 - iron pyrite or pyrite, ZnS - zinc blende or sphalerite (wurtzite), PbS - lead luster or galena, HgS - cinnabar, Sb2S3 - stibnite. In addition, sulfur is present in black gold, natural coal, natural gases and shale. Sulfur is the sixth most abundant element in natural waters, occurs mainly in the form of sulfate ions and causes the “permanent” hardness of fresh water. Vital important element for higher organisms, component many proteins are concentrated in the hair.
Sulfur is
History of discoverysulfur
sulfur in its native state, as well as in the form of sulfur compounds, has been known since ancient times. Man probably became familiar with the smell of burning sulfur, the suffocating effect of sulfur dioxide and the disgusting smell of hydrogen sulfide back in prehistoric times. It was because of these properties that sulfur was used by priests as part of sacred incense during religious rites. Sulfur was considered the work of superhuman beings from the world of spirits or underground gods. A very long time ago, sulfur began to be used as part of various flammable mixtures for military purposes. Homer already described “sulphurous fumes,” the deadly effect of burning sulfur emissions. Sulfur was probably part of the “Greek fire” that terrified opponents. Around the 8th century The Chinese began to use it in pyrotechnic mixtures, in particular, in mixtures such as gunpowder. The flammability of sulfur, the ease with which it combines with metals to form sulfides (for example, on the surface of pieces metal), explain the fact that it was considered the “principle of flammability” and an essential component of metal ores. Presbyter Theophilus (12th century) describes a method of oxidative roasting of copper sulfide ore, probably known back in ancient Egypt. IN period Arabian alchemy arose the mercury-sulfur theory of composition metals, according to which sulfur was revered as an essential component (father) of all metals. Later she became one of three principles alchemists, and later the “principle of flammability” became the basis of the theory of phlogiston. elemental nature Lavoisier established sulfur in his combustion experiments. With the introduction of gunpowder in Europe, the development of mining began natural sulfur, as well as the development of a method for obtaining it from pyrites; the latter was common in ancient Rus'. It was first described in literature by Agricola. Thus, the exact origin of sulfur has not been established, but, as stated above, this element was used before the birth of Christ, and therefore has been familiar to people since ancient times.
Sulfur occurs in nature in a free (native) state, so it was known to man already in ancient times. Sulfur attracted attention with its characteristic color, blue flames and a specific smell that occurs during combustion (the smell of sulfur dioxide). It was believed that burning sulfur drove away evil spirits. The Bible talks about the use of sulfur to cleanse sinners. For medieval people, the smell of “sulfur” was associated with the underworld. The use of burning sulfur for disinfection is mentioned by Homer. In ancient Rome, fabrics were bleached using sulfur dioxide.
Sulfur has long been used in medicine - patients were fumigated with its flame, it was included in various ointments for treatment skin diseases. In the 11th century Avicenna (Ibn Sina), and then European alchemists believed that metals, including silver, consist of those found in different ratios sulfur and mercury. Therefore, sulfur played an important role in alchemists' attempts to find the "philosopher's stone" and transform base metals into precious ones. In the 16th century Paracelsus considered sulfur, along with mercury and “salt,” one of the main “principles” of nature, the “soul” of all bodies.
The practical importance of sulfur increased sharply after the invention of black gunpowder (which necessarily includes sulfur). In 673, the Byzantines, defending Constantinople, burned the enemy fleet with the help of so-called Greek fire - a mixture of saltpeter, sulfur, resin and other substances - the flame of which was not extinguished by water. In the Middle Ages Europe Black gunpowder was used, the composition of which was close to a mixture of Greek fire. Since then it started wide use sulfur for military purposes.
It has long been known and critical connection sulfur - sulfuric acid. One of the creators of iatrochemistry, monk Vasily Valentin, in the 15th century described in detail the production of sulfuric acid by calcining iron sulfate ( old name sulfuric acid - oil of vitriol).
The elemental nature of sulfur was established in 1789 by A. Lavoisier. The names of chemical compounds containing sulfur often contain the prefix “thio” (for example, the Na2S2O3 reagent used in photography is called sodium thiosulfate). The origin of this prefix is related to the Greek name for sulfur - theion.
Origin of the name sulfur
The Russian name for sulfur goes back to the Proto-Slavic *sěra, which is associated with Lat. serum "serum".
Latin sulfur (a Hellenized spelling of the older sulpur) comes from the Indo-European root *swelp- “to burn.”
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 (that is, 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 deposits black gold or Natural gas, 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.
Mishraq was discovered in Iraq in 1961. 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. It's not just the neighborhood that matters minerals— 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 contains neither gypsum nor 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 subsoil. More from elementary school mathematics we all know that they can lead to the same result different ways. This extends to geochemistry as well.
Receiptsulfur
sulfur is obtained mainly by smelting native sulfur directly in places where it occurs underground. Sulfur ores are mined in 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.
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 sulfur smelter, where sulfur is extracted from the concentrate.
In 1890, Hermann Frasch proposed melting sulfur underground and pumping it to the surface through oil wells. The relatively low (113°C) melting point of sulfur confirmed the reality of Frasch’s idea. In 1890, tests began that led to success.
There are several known methods for obtaining sulfur from sulfur ores: steam-water, filtration, thermal, centrifugal and extraction.
Sulfur is also found in large quantities in Natural gas in a gaseous state (in the form of hydrogen sulfide, sulfur dioxide). During mining, it is deposited on the walls of pipes and equipment, rendering them inoperable. Therefore, it is recovered from the gas as quickly as possible after production. The resulting chemically pure fine sulfur is an ideal raw material for the chemical and rubber industries.
The largest deposit of native sulfur of volcanic origin is located on the island of Iturup with reserves of category A+B+C1 - 4227 thousand tons and category C2 - 895 thousand tons, which is enough to build an enterprise with a capacity of 200 thousand tons of granulated sulfur per year.
Manufacturerssulfur
The main sulfur producers in Russian Federation are enterprises OJSC Gazprom: LLC Gazprom Dobycha Astrakhan and LLC Gazprom Dobycha Orenburg, receiving it as a by-product during gas purification.
Propertiessulfur
1) Physical
sulfur differs significantly from oxygen in its ability to form stable chains and cycles of atoms. The most stable are the crown-shaped cyclic S8 molecules, which form orthorhombic and monoclinic sulfur. This is crystalline sulfur - a brittle yellow substance. In addition, molecules with closed (S4, S6) chains and open chains are possible. This composition has plastic sulfur, a substance Brown, which is obtained by sharply cooling the molten sulfur (plastic sulfur becomes brittle after just a few hours, acquires a yellow color and gradually turns into rhombic). The formula for sulfur is most often written simply S, since, although it has molecular structure, is a mixture simple substances with different molecules. Sulfur is insoluble in water; some of its modifications dissolve in organic solvents, such as carbon disulfide and turpentine. The melting of sulfur is accompanied by a noticeable increase in volume (approximately 15%). Molten sulfur is a yellow, easily mobile liquid, which above 160 °C turns into a very viscous dark brown mass. The sulfur melt acquires the highest viscosity at a temperature of 190 °C; a further increase in temperature is accompanied by a decrease in viscosity and above 300 °C the molten sulfur again becomes mobile. This is because when sulfur is heated, it gradually polymerizes, increasing the length of the chain as the temperature increases. When sulfur is heated above 190 °C, the polymer units begin to collapse. Sulfur can serve as the simplest example of an electret. When rubbed, sulfur acquires a strong negative charge.
Sulfur is used for the production of sulfuric acid, rubber vulcanization, as a fungicide in agriculture and as colloidal sulfur - medicinal product. Also, sulfur in sulfur bitumen compositions is used to produce sulfur asphalt, and as a substitute for Portland cement to produce sulfur concrete.
2) Chemical
Burning sulfur
In air, sulfur burns, forming sulfur dioxide - colorless gas with a pungent odor:
By using spectral analysis it has been established that in fact process The oxidation of sulfur into dioxide is a chain reaction and occurs with the formation of a number of intermediate products: sulfur monoxide S2O2, molecular sulfur S2, free sulfur atoms S and free radicals sulfur monoxide SO.
In addition to oxygen, sulfur reacts with many non-metals, however, at room temperature, sulfur reacts only with fluorine, exhibiting reducing properties:
Molten sulfur reacts with chlorine, and the formation of two lower chlorides is possible:
2S + Cl2 = S2Cl2
When heated, sulfur also reacts with phosphorus, apparently forming a mixture of phosphorus sulfides, among which is the higher sulfide P2S5:
In addition, when heated, sulfur reacts with hydrogen, carbon, silicon:
S + H2 = H2S (hydrogen sulfide)
C + 2S = CS2 (carbon disulfide)
When heated, sulfur interacts with many metals, often quite violently. Sometimes a mixture of metal and sulfur ignites when ignited. This interaction produces sulfides:
2Al + 3S = Al2S3
Solutions of alkali metal sulfides react with sulfur to form polysulfides:
Na2S + S = Na2S2
Of the complex substances, noteworthy first of all is the reaction of sulfur with molten alkali, in which sulfur is disproportionately similar to chlorine:
3S + 6KOH = K2SO3 + 2K2S + 3H2O
The resulting melt is called sulfur liver.
Sulfur reacts with concentrated oxidizing acids (HNO3, H2SO4) only during prolonged heating, oxidizing:
S + 6HNO3(conc.) = H2SO4 + 6NO2 + 2H2O
S + 2H2SO4(conc.) = 3SO2 + 2H2O
Sulfur is
Sulfur is
Fire hazardous properties of sulfur
Finely ground sulfur is prone to chemical spontaneous combustion in the presence of moisture, upon contact with oxidizing agents, and also in a mixture with coal, fats, and oils. Sulfur forms explosive mixtures with nitrates, chlorates and perchlorates. Spontaneously ignites on contact with bleach.
Extinguishing agents: sprayed water, air-mechanical foam.
According to V. Marshall, sulfur dust is classified as explosive, but for an explosion a sufficiently high concentration of dust is required - about 20 g/m3 (20,000 mg/m3), this concentration is many times higher than the maximum permissible concentration for humans in the air of a working area - 6 mg /m3.
Vapors form an explosive mixture with air.
The combustion of sulfur occurs only in a molten state, similar to the combustion of liquids. The top layer of burning sulfur boils, creating vapors that form a dimly luminous flame up to 5 cm high. The flame temperature when burning sulfur is 1820 °C.
Since air by volume consists of approximately 21% oxygen and 79% nitrogen, and when sulfur burns, one volume of oxygen produces one volume of SO2, the maximum theoretically possible SO2 content in gas mixture is 21%. In practice, combustion occurs with some excess air, and the volumetric SO2 content in the gas mixture is less than theoretically possible, usually amounting to 14...15%.
Detection of sulfur combustion by fire automatics is a difficult problem. The flame is difficult to detect with the human eye or a video camera; the spectrum of blue flame lies mainly in the ultraviolet range. Combustion occurs at low temperature. To detect combustion with a heat detector, it must be placed directly close to the sulfur. The flame of sulfur does not radiate infrared range. Thus, it will not be detected by common infrared detectors. They will only detect secondary fires. A sulfur flame does not release water vapor. Therefore, UV flame detectors that use nickel compounds will not work.
To comply with fire safety requirements at sulfur warehouses, it is necessary:
Structures and technological equipment must be regularly cleaned of dust;
The warehouse premises must be constantly ventilated by natural ventilation with the doors open;
Crushing sulfur lumps on the bunker grate should be done with wooden sledgehammers or tools made of non-sparking material;
Conveyors for supplying sulfur to production premises must be equipped with metal detectors;
In places where sulfur is stored and used, it is necessary to provide devices (boards, thresholds with a ramp, etc.) that ensure emergency situation preventing the spread of molten sulfur outside the room or open area;
At the sulfur warehouse it is prohibited:
Production of all types works using open fire;
Store and store oily rags and rags;
When making repairs, use tools made of non-sparking material.
Fires in sulfur warehouses
In December 1995, at an open sulfur warehouse enterprises, located in the city of Somerset West Western Cape Province Republic of South Africa A major fire occurred, killing two people.
On January 16, 2006, at about five in the evening, a warehouse with sulfur caught fire at the Cherepovets enterprise “Ammofos”. total area fire - about 250 square meters. It was possible to completely eliminate it only at the beginning of the second night. There are no casualties or injuries.
On March 15, 2007, early in the morning at Balakovo Fiber Materials Plant LLC, a fire occurred in a closed sulfur warehouse. The fire area was 20 sq.m. At the fire there were 4 fire crews with personnel for 13 people. After about half an hour, the fire was extinguished. No harm done.
On March 4 and 9, 2008, a sulfur fire occurred in the Atyrau region in the TCO sulfur storage facility at the Tengiz field. In the first case, the fire was extinguished quickly; in the second case, the sulfur burned for 4 hours. The volume of burned oil refining waste, which according to Kazakhstan laws attributed to sulfur, amounted to more than 9 thousand kilograms.
In April 2008, not far from the village of Kryazh, Samara region, a warehouse in which 70 tons of sulfur was stored caught fire. The fire was assigned the second category of complexity. 11 fire brigades and rescuers went to the scene of the incident. At that moment, when firefighters found themselves near the warehouse, not all of the sulfur was burning, but only a small part of it - about 300 kilograms. The area of the fire, including areas of dry grass adjacent to the warehouse, amounted to 80 square meters. Firefighters managed to quickly put out the flames and localize the fire: the fires were covered with earth and filled with water.
In July 2009, sulfur burned in Dneprodzerzhinsk. A fire occurred at one of the coke-chemical plants in the Bagleysky district of the city. The fire consumed more than eight tons of sulfur. None of the plant employees were injured.
Being in naturesulfur
WITH The era is quite widespread in nature. In the earth's crust its content is estimated at 0.05% by mass. In nature there are often significant deposits native sulfur (usually near volcanoes); V Europe they are located in the south of Italy, in Sicily. Even bigger deposits native sulfur is available in the USA (in the states of Louisiana and Texas), as well as in Central Asia, Japan, and Mexico. In nature, sulfur is found both in bulk and in the form of crystalline layers, sometimes forming amazingly beautiful groups of translucent yellow crystals (the so-called druses).
In volcanic areas, hydrogen sulfide gas H2S is often released from the ground; in these same regions, hydrogen sulfide is found dissolved in sulfuric waters. Volcanic gases often also contain sulfur dioxide SO2.
Deposits of various sulfide compounds are widespread on the surface of our planet. The most common among them are: iron pyrite (pyrite) FeS2, copper pyrite (chalcopyrite) CuFeS2, lead luster PbS, cinnabar HgS, sphalerite ZnS and its crystalline modification wurtzite, stibnite Sb2S3 and others. Numerous deposits of various sulfates are also known, for example, calcium sulfate (gypsum CaSO4 2H2O and anhydrite CaSO4), magnesium sulfate MgSO4 (bitter salt), barium sulfate BaSO4 (barite), strontium sulfate SrSO4 (celestine), sodium sulfate Na2SO4 10H2O (mirabilite ) and etc.
Hard coals contain an average of 1.0-1.5% sulfur. Sulfur may also be part of black gold. A number of natural combustible gas fields (for example, Astrakhan) contain hydrogen sulfide as an impurity.
Sulfur is one of the elements that are essential for living organisms, as it is an essential component of proteins. Proteins contain 0.8-2.4% (by weight) of chemically bound sulfur. Plants obtain sulfur from sulfates found in the soil. Unpleasant odors arising from rotting animal corpses are mainly explained by the release of sulfur compounds (hydrogen sulfide and mercaptans) formed during the decomposition of proteins. IN sea water about 8.7·10-2% sulfur is present.
Receiptsulfur
WITH Sulfur is obtained mainly by smelting it from rocks containing native (elemental) sulfur. The so-called geotechnological method makes it possible to obtain sulfur without raising ore to the surface. This method was proposed at the end of the 19th century by the American chemist G. Frasch, who was faced with the task of extracting sulfur from the deposits of the south to the surface of the earth USA, where the sandy soil greatly complicated its extraction using the traditional mine method.
Frasch proposed using superheated water vapor to lift sulfur to the surface. Superheated steam is fed through a pipe into an underground layer containing sulfur. The sulfur melts (its melting point is slightly below 120°C) and rises to the top through a pipe located inside the one through which water vapor is pumped underground. In order to ensure the rise of liquid sulfur, compressed air is pumped through the thinnest inner tube.
According to another (thermal) method, which became especially widespread at the beginning of the 20th century in Sicily, sulfur is smelted, or sublimated, from crushed rock in special clay ovens.
There are other methods for separating native sulfur from rock, for example, by extraction with carbon disulfide or flotation methods.
Due to the fact that the need industry in sulfur is very high, methods have been developed for its production from hydrogen sulfide H2S and sulfates.
The method of oxidizing hydrogen sulfide to elemental sulfur was first developed in Great Britain, where they learned to obtain significant amounts of sulfur from the Na2CO3 remaining after the production of soda using the method French chemist N. Leblanc calcium sulfide CaS. Leblanc's method is based on the reduction of sodium sulfate with coal in the presence of limestone CaCO3.
Na2SO4 + 2C = Na2S + 2CO2;
Na2S + CaCO3 = Na2CO3 + CaS.
The soda is then leached with water, and the aqueous suspension of poorly soluble calcium sulfide is treated with carbon dioxide:
CaS + CO2 + H2O = CaCO3 + H2S
The resulting hydrogen sulfide H2S mixed with air is passed in a furnace over a catalyst bed. In this case, due to the incomplete oxidation of hydrogen sulfide, sulfur is formed:
2H2S + O2 = 2H2O +2S
A similar method is used to obtain elemental sulfur from hydrogen sulfide accompanying natural gases.
Because modern technology needs sulfur of high purity, effective methods for refining sulfur have been developed. In this case, in particular, differences in the chemical behavior of sulfur and impurities are used. Thus, arsenic and selenium are removed by treating sulfur with a mixture of nitric and sulfuric acids.
Using methods based on distillation and rectification, it is possible to obtain high-purity sulfur with an impurity content of 10-5 - 10-6% by weight.
Applicationsulfur
ABOUT About half of the sulfur produced is used to produce sulfuric acid, about 25% is spent to produce sulfites, 10-15% is used to control pests of agricultural crops (mainly grapes and cotton) ( highest value has a solution here copper sulfate CuSO4 5H2O), about 10% is used by rubber industry for rubber vulcanization. Sulfur is used in the production of dyes and pigments, explosives (it is still part of gunpowder), artificial fibers, and phosphors. Sulfur is used in the production of matches, as it is part of the composition from which match heads are made. Some ointments that are used to treat skin diseases still contain sulfur. To give steels special properties small additions of sulfur are introduced into them (although, as a rule, an admixture of sulfur in steels undesirable).
Biological rolesulfur
WITH era is constantly present in all living organisms, being an important biogenic element. Its content in plants is 0.3-1.2%, in animals 0.5-2% (marine organisms contain more sulfur than terrestrial ones). Biological significance sulfur is determined primarily by the fact that it is part of the amino acids methionine and cysteine and, therefore, part of peptides and proteins. Disulfide bonds -S-S- in polypeptide chains are involved in the formation of the spatial structure of proteins, and sulfhydryl groups (-SH) play an important role in the active centers of enzymes. In addition, sulfur is included in hormone molecules, important substances. A lot of sulfur is contained in the keratin of hair, bones, and nervous tissue. Inorganic compounds sulfur is necessary for the mineral nutrition of plants. They serve as substrates oxidative reactions carried out by sulfur bacteria common in nature.
The body of an average person (body weight 70 kg) contains about 1402 g of sulfur. The daily requirement of an adult for sulfur is about 4.
However, due to its negative impact on environment and in humans, sulfur (more precisely, its compounds) is in one of the first places. The main source of sulfur pollution is the combustion of coal and other fuels containing sulfur. At the same time, about 96% of the sulfur contained in the fuel enters the atmosphere in the form of sulfur dioxide SO2.
In the atmosphere, sulfur dioxide is gradually oxidized to sulfur oxide (VI). Both oxides - sulfur oxide (IV) and sulfur oxide (VI) - react with water vapor to form an acidic solution. These solutions then fall out in the form of acid rain. Once in the soil, acidic water inhibits the development of soil fauna and plants. As a result, unfavourable conditions for the development of vegetation, especially in northern regions, where the harsh climate adds chemical pollution. As a result, forests are dying, grass cover is being destroyed, and the condition of water bodies is deteriorating. Acid rain destroy monuments made of marble and other materials, moreover, they cause the destruction of even stone buildings and trade items from metals. Therefore, it is necessary to take various measures to prevent the release of sulfur compounds from fuel into the atmosphere. To do this, petroleum products are purified from sulfur compounds and the gases generated during fuel combustion are purified.
Sulfur itself in the form of dust irritates the mucous membranes, respiratory organs and can cause serious illnesses. The maximum permissible concentration of sulfur in the air is 0.07 mg/m3.
Many sulfur compounds are toxic. Particularly noteworthy is hydrogen sulfide, inhalation of which quickly dulls the reaction to its unpleasant odor and can lead to severe poisoning even with fatal. The maximum permissible concentration of hydrogen sulfide in the air of working premises is 10 mg/m3, in atmospheric air 0.008 mg/m3.
Sources
Chemical encyclopedia: in 5 volumes / Editorial Board: Zefirov N. S. (chief editor). - Moscow: Soviet encyclopedia, 1995. - T. 4. - P. 319. - 639 p. — 20,000 copies. — ISBN 5—85270—039—8
Great Medical Encyclopedia
SULFUR- chem. element, symbol S (lat. Sulfur), at. n. 16, at. m. 32.06. Exists in the form of several allotropic modifications; among them are sulfur of the monoclinic modification (density 1960 kg/m3, tmelt = 119°C) and orthorhombic sulfur (density 2070 kg/m3, ίπι = 112.8... ... Big Polytechnic Encyclopedia
SULFUR- (denoted S), a chemical element of group VI of the PERIODIC TABLE, a non-metal, known since antiquity. Occurs in nature both as a separate element and in the form of sulfide minerals such as GALENITE and PYRITE, and sulfate minerals,... ... Scientific and technical encyclopedic dictionary
sulfur- In the mythology of the Irish Celts, Sera is the father of Parthalon (see chapter 6). According to some sources, it was Sera, and not Parthalon, who was Dilgneid's husband. (
Sulfur is one of the elements represented on the periodic table. The substance is classified in group 16, under the third period. The atomic number of sulfur is 16. In nature, it can be found both in pure form and in mixed form. In chemical formulas, sulfur is denoted Latin letter S. It is an element in many proteins and has a large number physical and chemical properties, which makes it in demand.
Physical and chemical properties of sulfur
Basic physical properties sulfur:
- Solid crystalline composition (rhombic form with a light yellow color and monoclinic form, distinguished by a honey-yellow color).
- Color change when temperature increases from 100°C.
- Temperature at which an element becomes liquid state of aggregation– 300°С.
- Has low thermal conductivity.
- Does not dissolve in water.
- Easily dissolves in ammonia concentrate and carbon disulfide.
Main chemical features of sulfur:
- It is an oxidizing agent for metals and forms sulfides.
- Actively interacts with hydrogen at temperatures up to 200°C.
- Forms oxides when interacting with oxygen at temperatures up to 280°C.
- It interacts well with phosphorus, carbon as an oxidizing agent, and also with fluorine and other complex substances as a reducing agent.
Where can sulfur be found in nature?
Native sulfur in large volumes is not often found in nature. As a rule, it is found in certain ores. Rock with pure sulfur crystals is called sulfur-flagged ore.
The further orientation of exploration and prospecting work directly depends on how these inclusions were formed in the rock. But humanity has not yet found a clear answer to this question.
There are many different theories on the origin of native sulfur in rocks, but not one has been fully proven, since the formation of this element is quite complex. Working versions of the formation of sulfur ore include:
- syngenesis theory: simultaneous origin of sulfur with host rocks;
- theory of epigenesis: formation of sulfur later than basic rocks;
- theory of metasomatism: one of the subtypes of the theory of epigenesis, consists in the transformation of gypsum and anhydride into sulfur.
Scope of application
Sulfur is used to make various materials, among which:
- paper and matches;
- paints and fabrics;
- medicines and cosmetics;
- rubber and plastic;
- flammable mixtures;
- fertilizers;
- explosives and poisons.
To produce one car, you need to spend 14 kg of this substance. Thanks to such a wide range of sulfur uses, we can safely say that the production potential of the state depends on its reserves and consumption.
The lion's share of world ore production goes into paper production, as sulfur compounds contribute to the production of cellulose. To produce 1 ton of this raw material, it is necessary to consume more than 1 centner of sulfur. Large volumes of this substance are necessary to obtain rubber during the vulcanization of rubbers.
Application of sulfur in agriculture and mining chemical industry
Sulfur, both in pure form and in the form of compounds, is widely used in agriculture. It is found in mineral fertilizers and pesticides. Sulfur is useful for plants, like phosphorus, potassium and other substances, although the bulk of the fertilizer applied to the soil is not absorbed by them, but contributes to the absorption of phosphorus.
Therefore, sulfur is added to the ground at the same time as phosphate rock. Bacteria in the soil oxidize it and form sulfuric and sulfurous acids, which react with phosphorites, forming phosphorus compounds, well absorbed by plants.
The mining and chemical industry is a leader among sulfur consumers. About half of all resources mined in the world are used to produce sulfuric acid. To produce one ton of this substance, it is necessary to spend 3 quintals of sulfur. And sulfuric acid in chemical industry comparable to the role of water for a living organism.
Significant volumes of sulfur and sulfuric acid are needed in the production of explosives and. The substance, purified from all kinds of additives, is necessary in the production of dyes and luminous compounds.
Sulfur compounds are used in the oil refining industry. They are precisely what is needed in the process of producing anti-knock agents, machine oils and lubricants for ultra-high pressure units, as well as in coolants that accelerate metal processing, which can contain up to 18% sulfur.
Sulfur is indispensable in the mining industry and in production large number food products.
Sulfur deposits are places where sulfur ore accumulates. According to research data, the world's sulfur deposits are equal to 1.4 billion tons. Today, deposits of these ores have been found in different parts of the planet. In Russia - near the left banks of the Volga and in the Urals, and also in Turkmenistan. There are many ore deposits in the USA, namely in Texas and Louisiana. Deposits of crystalline sulfur have been found and are still being developed in the Italian regions of Sicily and Romagna.
Sulfur ores are classified according to the percentage of this component they contain. Thus, a distinction is made between rich ores with a sulfur content of more than 25% and poor ores of up to 12%. There are also sulfur deposits:
Finding sulfur in nature
- stratiform;
- salt domes;
- volcanogenic.
This type of deposit, stratiform, is the most popular. These mines account for 60% of global production. A special feature of such deposits is their connection with sulfate-carbonate deposits. Ores are located in sulfate rocks. The dimensions of sulfur bodies can reach several hundred meters and have a thickness of several tens of meters.
Salt dome type mines account for 35% of the total world sulfur production. They are characterized by gray sulfur ores.
The share of volcanic mines is 5%. They were formed as a result of volcanic eruptions. The morphology of ore bodies in such deposits has a sheet-like or lens-shaped appearance. Such mines contain about 40% sulfur. Volcanic-type deposits are characteristic of the Pacific volcanic belt.
In addition to native sulfur, an important mineral that contains sulfur and its compounds is iron pyrite or pyrite. Most of the world's pyrite production comes from European countries. Mass fraction sulfur compounds in pyrite is 80%. The leaders in ore production include Spain, South Africa, Japan, Italy and the United States of America.
Mining process
Sulfur mining is carried out by one of possible methods, the choice of which depends on the type of deposit. Mining can be open pit or underground.
Open pit mining of sulfur ore is the most common. At the beginning of the sulfur extraction process using this method, a significant layer of rock soil is removed by excavators. Then the ore itself is crushed. The extracted pieces of ore are transported to processing plants to undergo a purification procedure. After this, the sulfur is sent to production, where it is melted and the final substance is obtained from concentrates.
Underground melting method
In addition, the Frasch method, which is based on underground smelting of sulfur, can also be used. This approach is advisable to use for deep deposits of matter. After the fossil has been melted in the mine, liquid sulfur is pumped out. For this purpose, special wells are installed. The Frasch method is feasible only due to the ease of melting of the substance and its relatively low density.
Method of separating ore using centrifuges
Its peculiarity lies in one negative feature: sulfur obtained through a centrifuge has many impurities and requires additional purification. As a result, this method is considered quite expensive.
Ore mining in some cases can be carried out using the following methods:
- steam-water;
- borehole;
- filtration;
- extraction;
- thermal.
Regardless of which approach will be used to extract from the bowels of the earth, strict adherence to safety standards and regulations is required. Main danger process of developing sulfur ore is that toxic and explosive hydrogen sulfide can accumulate in its deposits.