Sulfur is an element periodic table chemical elements and belongs to the group of chalcogens. This item is an active participant in the formation of many acids and salts. Hydrogen and acidic compounds contain sulfur, usually as part of various ions. A large number of salts that contain sulfur are practically insoluble in water.
Sulfur is a fairly common element in nature. In my own way chemical content in the earth's crust it is assigned number sixteen, and based on its location in water bodies - number six. It can occur in both free and bound states.
To the most important natural minerals elements include: iron pyrite (pyrite) - FeS 2, zinc blende (sphalerite) - ZnS, galena - PbS, cinnabar - HgS, stibnite - Sb 2 S 3. Also, the sixteenth element of the periodic table is found in oil, natural coal, natural gases, and shale. Finding sulfur in aquatic environment appears to be sulfate ions. It is its presence in fresh water that causes constant hardness. She is also one of essential elements vital activity of higher organisms, is part of the structure of many proteins, and is also concentrated in the hair.
| Characteristic | Meaning |
|---|---|
| Properties of the atom | |
| Name, symbol, number | Sulfur/Sulfur (S), 16 |
| Atomic mass (molar mass) | [comm. 1] a. e.m. (g/mol) |
| Electronic configuration | 3s2 3p4 |
| Atomic radius | 127 pm |
| Chemical properties | |
| Valence radius | 102 pm |
| Ion radius | 30 (+6e) 184 (-2e) pm |
| Electronegativity | 2.58 (Pauling scale) |
| Electrode potential | 0 |
| Oxidation state | +6, +4, +2, +1, 0, -1, −2 |
| Ionization energy (first electron) | 999.0 (10.35) kJ/mol (eV) |
| Thermodynamic properties of a simple substance | |
| Density (at normal conditions) | 2.070 g/cm³ |
| Melting temperature | 386 K (112.85 °C) |
| Boiling temperature | 717.824 K (444.67 °C) |
| Ud. heat of fusion | 1.23 kJ/mol |
| Ud. heat of vaporization | 10.5 kJ/mol |
| Molar heat capacity | 22.61 J/(K mol) |
| Molar volume | 15.5 cm³/mol |
|
Crystal lattice of a simple substance |
|
| Lattice structure | orthorhombic |
| Lattice parameters | a=10.437 b=12.845 c=24.369 Å |
| Other characteristics | |
| Thermal conductivity | (300 K) 0.27 W/(m K) |
| CAS number | 7704-34-9 |
Sulfur ore
It cannot be said that the free state of sulfur in nature is a common occurrence. Native sulfur is quite rare. It is often one of the components of some ores. Sulfur ore is a rock that contains native sulfur. Sulfur inclusions in rocks can form together with accompanying rocks or later than them. The time of their formation affects the direction of prospecting and exploration work. Experts identify several theories for the formation of sulfur in ores.
- Syngenesis theory. According to this theory, sulfur and host rocks were formed simultaneously. The place of their formation were shallow basins. The sulfates contained in the water were reduced to hydrogen sulfide with the help of special bacteria. Next, it rose up to the oxidation zone, in which hydrogen sulfide was oxidized to elemental sulfur. It sank to the bottom, settling in silt, which over time turned into ore.
- The theory of epigenesis, which states that the formation of sulfur inclusions occurred later than the main rocks. In accordance with this theory, it is believed that penetration occurred groundwater into the rock strata, as a result of which the water was enriched with sulfates. Next, these waters came into contact with oil or gas deposits, which led to the reduction of sulfate ions with the help of hydrocarbons to hydrogen sulfide, which, rising to the surface and oxidizing, released native sulfur in the voids and cracks of the rocks.
- The theory of metasomatism. This theory is one of the subtypes of the theory of epigenesis. Currently, it is increasingly being confirmed. Its essence lies in the conversion of gypsum (CaSO 4 -H 2 O) and anhydrite (CaSO 4) into sulfur and calcite (CaCO 3-). The theory was proposed by two scientists Miropolsky and Krotov in the first half of the twentieth century. A few years later, the Mishrak deposit was found, which confirmed the formation of sulfur in this way. However, the process of transformation of gypsum into sulfur and calcite remains unclear to this day. In this regard, the theory of metasomatism is not the only correct one. In addition, today there are lakes on the planet that have syngenetic sulfur deposits, however, gypsum or anhydrite have not been found in the silt. Such lakes include Sernoye Lake, located near Sernovodsk.
Thus, there is no unambiguous theory of the origin of sulfur inclusions in ores. The formation of matter largely depends on the conditions and phenomena occurring in the bowels of the earth.
Sulfur deposits
Sulfur is mined in places where sulfur ore is localized - deposits. According to some reports, world sulfur reserves amount to about 1.4 billion tons. Today, sulfur deposits have been found in many corners of the Earth - in Turkmenistan, the USA, the Volga region, near the left banks of the Volga, which run from Samara, etc. Sometimes the rock strip can extend for several kilometers.
Texas and Louisiana are famous for their large sulfur reserves. Sulfur crystals, distinguished by their beauty, are also located in Romagna and Sicily (Italy). The island of Vulcano is considered the birthplace of monoclinic sulfur. Russia, in particular the Urals, is also famous for its deposits of the sixteenth element of Mendeleev’s periodic table.
Sulfur ores are classified according to the amount of sulfur they contain. Thus, among them there are rich ores (from 25% sulfur) and poor ores (about 12% of the substance). Sulfur deposits, in turn, are divided into the following types:
- Stratiform deposits (60%). This type of deposits is associated with sulfate-carbonate strata. Ore bodies are located directly in sulfate rocks. They can reach hundreds of meters in size and have a thickness of several tens of meters;
- Salt dome deposits (35%). For of this type characterized by sulfur deposits gray;
- Volcanogenic (5%). This type includes deposits formed by volcanoes of a young and modern structure. The shape of the ore element occurring in them is sheet-like or lens-shaped. Such deposits may contain about 40% sulfur. They are characteristic of the Pacific volcanic belt.
Sulfur mining
Sulfur is mined by one of several possible ways, the choice of which depends on the conditions of occurrence of the substance. There are only two main ones - open and underground.
The open-pit method of sulfur extraction is the most popular. The entire process of extracting a substance using this method begins with the removal of a significant amount of rock by excavators, after which the ore itself is crushed. The resulting ore blocks are transported to the factory for further enrichment, after which they are transported to the enterprise where sulfur is smelted and the substance is obtained from concentrates.
In addition, the Frasch method is also sometimes used, which involves smelting sulfur underground. This method It is advisable to use in places where the substance is deep. After melting underground, the substance is pumped out. For this purpose, wells are formed, which are the main tool for pumping out the molten substance. The method is based on the ease of melting of the element and its low density.
There is also a centrifuge separation method. However, it has one big drawback, based on the fact that sulfur obtained using this method has many impurities and requires additional purification. As a result, the method is considered quite expensive.
In addition to the above methods, sulfur extraction in some cases can also be carried out:
- borehole method;
- steam-water method;
- filtration method;
- thermal method;
- extraction method.
It is worth noting that regardless of the method used during the extraction of a substance from the bowels of the earth, it is necessary Special attention pay attention to safety precautions. This is due to the presence of hydrogen sulfide along with sulfur deposits, which is toxic to humans and flammable.
Sulfur (from lat. sērum“serum”) is a mineral of the class of native elements, a non-metal. Latin name associated with Indo-European root swelp - “burn”. Chemical formula: S.
Sulfur, unlike other native elements, has a molecular lattice, which determines its low hardness (1.5-2.5), lack of cleavage, fragility, uneven fracture and the resulting greasy splash; Only on the surface of the crystals is a glassy sheen observed. Specific gravity 2.07 g/cm3. It has poor electrical conductivity, weak thermal conductivity, low melting point (112.8°C) and ignition point (248°C). Lights easily with a match and burns with a blue flame; this produces sulfur dioxide, which has a pungent, suffocating odor. The color of native sulfur is light yellow, straw yellow, honey yellow, greenish; sulfur containing organic matter, acquire a brown, gray, black color. Volcanic sulfur bright yellow, orange, greenish. In some places it usually has a yellowish tint. The mineral is found in the form of continuous dense, sintered, earthy, powdery masses; There are also overgrown crystals, nodules, plaques, crusts, inclusions and pseudomorphs of organic residues. Rhombic syngony.
Features : native sulfur is characterized by: a non-metallic luster and the fact that it ignites with a match and burns, releasing sulfur dioxide, which has a sharp suffocating odor. The most characteristic color of native sulfur is light yellow.
Variety:
Vulcanite(selenium sulfur). Orange-red, red-brown color. The origin is volcanic.
Monoclinic sulfur Crystalline sulfur Crystalline sulfur Selenous sulfur - vulcanite
Chemical properties of sulfur
It ignites with a match and burns with a blue flame, which produces sulfur dioxide, which has a pungent, suffocating odor. Melts easily (melting point 112.8° C). Ignition temperature 248°C. Sulfur dissolves in carbon disulfide.
Origin of sulfur
Native sulfur of natural and volcanic origin is found. Sulfur bacteria live in water pools enriched with hydrogen sulfide due to the decomposition of organic residues - at the bottom of swamps, estuaries, and shallow sea bays. The Black Sea estuaries and Sivash Bay are examples of such bodies of water. The concentration of sulfur of volcanic origin is confined to volcanic vents and to the voids of volcanic rocks. During volcanic eruptions, various sulfur compounds (H 2 S, SO 2) are released, which are oxidized in surface conditions, which leads to its reduction; in addition, sulfur is sublimated directly from the vapor.
Sometimes, during volcanic processes, sulfur is ejected in liquid form. This happens when sulfur, previously deposited on the walls of the craters, melts as the temperature rises. Sulfur is also deposited from hot aqueous solutions as a result of the decay of hydrogen sulfide and sulfur compounds released in one of the later phases of volcanic activity. These phenomena are now observed near the geyser vents of Yellowstone Park (USA) and Iceland. It is found together with gypsum, anhydrite, limestone, dolomite, rock and potassium salts, clays, bituminous deposits (oil, ozokerite, asphalt) and pyrite. It is also found on the walls of volcanic craters, in cracks in lavas and tuffs surrounding the vents of volcanoes, both active and extinct, near sulfur deposits. mineral springs.
Satellites. Among sedimentary rocks: gypsum, anhydrite, calcite, dolomite, siderite, rock salt, sylvite, carnallite, opal, chalcedony, bitumens (asphalt, oil, ozokerite). In deposits formed as a result of sulfide oxidation, there is mainly pyrite. Among the products of volcanic sublimation: gypsum, realgar, orpiment.
Application
Widely used in chemical industry. Three quarters of sulfur production is used to produce sulfuric acid. It is also used to control agricultural pests, in addition, in the paper, rubber industries (rubber vulcanization), in the production of gunpowder, matches, pharmaceuticals, glass, Food Industry.
Sulfur deposits
On the territory of Eurasia, all industrial deposits of native sulfur are of surface origin. Some of them are located in Turkmenistan, in the Volga region, etc. Rocks containing sulfur stretch along the left bank of the Volga from the city of Samara in a strip several kilometers wide to Kazan. Sulfur probably formed in lagoons during the Permian period as a result of biochemical processes. Sulfur deposits are located in Razdol (Lviv region, Carpathian region), Yavorovsk (Ukraine) and in the Ural-Embinsky region. In the Urals (Chelyabinsk region) sulfur is found, formed as a result of the oxidation of pyrite. Sulfur of volcanic origin is found in Kamchatka and the Kuril Islands. The main reserves are located in Iraq, the USA (Louisiana and Utah), Mexico, Chile, Japan and Italy (Sicily).
Description and properties of sulfur
Sulfur is a substance that is in group 16, under the third period and has an atomic number of 16. It can be found both in native and bound form. Sulfur is designated by the letter S. Known sulfur formula– (Ne)3s 2 3p 4 . Sulfur as an element is included in many proteins.
The photo shows sulfur crystals
If speak about atomic structure of the element sulfur, then in its outer orbit there are electrons whose valence number reaches six.
This explains the element's property of being maximally hexavalent in most combinations. There are four isotopes in the structure of a natural chemical element, and these are 32S, 33S, 34S and 36S. Speaking of external electron shell, the atom has a 3s2 3p4 scheme. The radius of the atom is 0.104 nanometers.
Properties of sulfur are primarily divided into physical type. This includes the fact that the element has a solid crystalline composition. Two allotropic modifications are the main state in which this sulfur element is stable.
The first modification is rhombic, lemon-yellow in color. Its stability is lower than 95.6 °C. The second is monoclinic, having a honey-yellow color. Its resistance ranges from 95.6 °C and 119.3 °C.
The photo shows the mineral sulfur
During the melting chemical element becomes a moving liquid that has a yellow color. It turns brown, reaching temperatures of more than 160 °C. And at 190 °C sulfur color turns into dark brown. After reaching 190 °C, a decrease in the viscosity of the substance is observed, which nevertheless becomes liquid after heating to 300 °C.
Other properties of sulfur:
Practically does not conduct heat or electricity.
Does not dissolve when immersed in water.
It is soluble in ammonia, which has an anhydrous structure.
It is also soluble in carbon disulfide and other organic solvents.
TO characteristics of the element sulfur it is important to add it too chemical features. She is active in this regard. If sulfur is heated, it can simply combine with almost any chemical element.
The photo shows a sample of sulfur mined in Uzbekistan
With the exception of inert gases. Upon contact with metals, chemicals. the element forms sulfides. Room temperature allows the element to react with. Increased temperature increases the activity of sulfur.
Let's consider how sulfur behaves with individual substances:
With metals it is an oxidizing agent. Forms sulfides.
With hydrogen - at high temperatures– up to 200 °C active interaction occurs.
With oxygen. Oxides form at temperatures up to 280 °C.
With phosphorus, carbon – it is an oxidizing agent. Only if there is no air during the reaction.
With fluorine it acts as a reducing agent.
With substances having complex structure– also as a reducing agent.
Sulfur deposits and production
The main source for obtaining sulfur is its deposits. In total, there are 1.4 billion tons of reserves of this substance worldwide. It is mined both by open and underground mining and by smelting from underground.
The photo shows sulfur mining in the Kawa Ijen volcano
If applicable last case, then water is used, which is overheated and melts the sulfur with it. In low-grade ores, the element is contained in approximately 12%. Rich – 25% and more.
Common types of deposits:
Stratiform – up to 60%.
Salt dome – up to 35%.
Volcanogenic – up to 5%.
The first type is associated with thicknesses, bearing the name sulfate-carbonate. At the same time, ore bodies that have a thickness of up to several tens of meters and a size of up to hundreds of meters are located in sulfate rocks.
Also, these strata deposits can be found among rocks of sulfate and carbonate origin. The second type is characterized by gray deposits, which are confined to salt domes.
The latter type is associated with volcanoes that have young and modern structure. In this case, the ore element has a sheet-like, lens-shaped shape. It may contain sulfur in the amount of 40%. This type of deposit is common in the Pacific volcanic belt.
Sulfur deposit in Eurasia is located in Turkmenistan, the Volga region and other places. Sulfur rocks are found near the left banks of the Volga, which stretch from Samara. The width of the rock strip reaches several kilometers. Moreover, they can be found all the way to Kazan.
The photo shows sulfur in rock
In Texas and Louisiana, huge amounts of sulfur are found in the roofs of salt domes. Particularly beautiful Italians of this element are found in Romagna and Sicily. And on the island of Vulcano they find monoclinic sulfur. The element, which was oxidized by pyrite, was found in the Urals in the Chelyabinsk region.
For mining sulfur chemical element use different ways. It all depends on the conditions of its occurrence. At the same time, of course, special attention is paid to safety.
Since hydrogen sulfide accumulates along with sulfur ore, it is necessary to take a particularly serious approach to any mining method, because this gas is poisonous to humans. Sulfur also tends to ignite.
Most often used open method. So, with the help of excavators, significant parts of the rocks are removed. Then the ore part is crushed using explosions. The lumps are sent to the factory for enrichment. Then - to the sulfur smelting plant, where sulfur is obtained from concentrate.
The photo shows sulfur in the port, brought by sea
In the case of deep occurrence of sulfur in many volumes, the Frasch method is used. The sulfur melts while still underground. Then, like oil, it is pumped out through a broken well. This approach is based on the fact that the element melts easily and has a low density.
A separation method using centrifuges is also known. Only this method has a drawback: sulfur is obtained with impurities. And then it is necessary to carry out additional cleaning.
In some cases, the borehole method is used. Other possibilities for mining the sulfur element:
Steam-water.
Filtration.
Thermal.
Centrifugal.
Extraction.
Application of sulfur
Most of The extracted sulfur is used to make sulfuric acid. And the role of this substance is very huge in chemical production. It is noteworthy that to obtain 1 ton sulfuric matter 300 kg of sulfur is needed.
Sparklers, which glow brightly and have many dyes, are also made using sulfur. The paper industry is another area where a significant portion of the extracted substance goes.
Pictured is sulfur ointment
More often application of sulfur finds when meeting production needs. Here are some of them:
Use in chemical production.
For the production of sulfites, sulfates.
Production of substances for fertilizing plants.
To obtain non-ferrous types of metals.
To give steel additional properties.
For making matches, materials for explosions and pyrotechnics.
Paints and fibers from artificial materials are produced using this element.
For bleaching fabrics.
In some cases sulfur element included in ointments that treat skin diseases.
Sulfur price
By latest news The need for sulfur is actively growing. Cost per Russian product equals 130 dollars. For the Canadian version – $145. But in the Middle East, prices increased to $8, resulting in a cost of $149.
The photo shows a large specimen of the mineral sulfur
In pharmacies you can find ground sulfur powder at a price of 10 to 30 rubles. In addition, it is possible to buy it in bulk. Some organizations offer to purchase granular technical equipment at a low price. gas sulfur.
In the eastern part of the island of Java, which is located in Indonesia, there is a place of amazing beauty, but very dangerous in nature - the Kawah Ijen volcano. The volcano is located at an altitude of about 2400 meters above sea level, the diameter of its crater is 175 meters, and the depth is 212 meters. In its mouth there is probably the strangest and most frightening lake of a beautiful apple-emerald color, in which only the Terminator would dare to swim, since instead of water in it sulfuric acid. Or rather, a mixture of sulfuric and of hydrochloric acid volume of 40 million tons.
Renowned French photographer Olivier Grunewald recently made several trips to the sulfur mines in the crater of the Kawaha Ijen volcano in East Java, Indonesia. There, using special equipment, he took breathtaking, surreal photographs of the place in the moonlight, illuminated by torches and the blue flames of burning molten sulfur.
Descent into the caldera of the Kawaha Ijen volcano, where there is a lake with sulfuric acid a kilometer wide. Sulfur is mined on its banks
Each liter of this deadly slurry contains an additional 5 grams of molten aluminum. In total, the lake, according to rough estimates, contains more than 200 tons of aluminum. On the surface of the lake the temperature fluctuates around 60 degrees, and at its bottom it’s all 200!
Acidic gases and steam are released from yellowish pieces of sulfur
So that people could imagine the danger the lake poses to their lives, an experiment was conducted. A sheet of aluminum was lowered into the lake for 20 minutes; even as it was immersed, it began to become covered with bubbles, and after all this time, the aluminum sheet became thin, like a piece of fabric.
A worker breaks off a piece of solid sulfur. Then the sulfur is carried to the weighing station.
However, the lake and the crater of the Kawah Ijen volcano itself are not used to attract tourists, but for the extraction of sulfur in conditions that are very unfavorable for humans. And there is a countless amount of sulfur in this crater, but since this is still Southeast Asia, manual labor is completely used.
Night. A miner with a torch is inside the crater of the Ijen Kawaha volcano, looking at a stream of liquid sulfur glowing an uncanny blue.
Workers – local residents Without any protective suits or gas masks, and inhaling the smell of sulfur is even disgusting, they mine pieces of sulfur day and night, using only their unprotected hands and a scarf tied on their face to protect their mouth and nose.
Miners work here in hellish conditions while mining sulfur. Photographer Olivier Grunewald described the smell here as unbearable, requiring a mask or gas mask for safety. Some of the miners wear them, the rest work without them.
Miners with crowbars used to break off pieces of sulfur:
A worker puts pieces of sulfur into baskets to carry it out of the volcano:
Do you think this is all drawn? Watch the video:
Did you believe it?
These bizarre shapes were formed from a flow of liquid sulfur inside the crater of the Kawaha Ijen volcano. When sulfur is molten, it is blood red in color. As it cools it becomes more and more yellow
Molten sulfur drips from a ceramic pipe that condenses sulfur gases from the volcano into liquid. Then it cools, hardens, and workers mine it
The miner reached his destination with his cargo. The miners make two or three trips for sulfur per day, receiving hard labour about $13 US per shift
Mechanism for initial sulfur processing, where large pieces are broken down into smaller pieces
Then pieces of sulfur are placed over the fire and it melts again
Molten sulfur is poured into containers
The last stage of this process is the distribution of liquid sulfur on the cooling plates. Once it has cooled and turned into sulfur sheets, they are sent to local rubber vulcanization plants and other industrial facilities.
Photographer Olivier Grunewald: “It feels like you’re on another planet.” Grunewald lost one camera and two lenses in the harsh conditions of the crater. When filming was finished, he threw all his belongings in the trash: the sulfur smell was so strong that it would be impossible to get rid of it.
And now the daily report from this mine:
An Indonesian miner carries sulfur from Ijen on May 24, 2009 near Banyuwangi, East Java, Indonesia.
An acid-filled lake inside the crater of the Ijen volcano is 200 meters deep and a kilometer wide. Photo taken on May 24, 2009 in East Java, Indonesia. The lake is filled with a solution of sulfuric acid and hydrogen chloride at a temperature of 33 Cº.
A worker repairs pipes in which sulfur dioxide gases condense. Ijen volcano complex May 24, 2009 in the vicinity of Banyuwangi, East Java, Indonesia.
A miner extracts sulfur from a pipe at the Ijen volcano crater May 24, 2009 in East Java, Indonesia. The molten sulfur flows out of the pipes in a deep red color, and as it cools, it gradually turns yellow and hardens.
Workers are repairing pipes in which sulfur dioxide gases condense. Ijen volcano complex May 24, 2009 in the vicinity of Banyuwangi, East Java, Indonesia.
A miner extracts sulfur from a pipe near the Ijen volcano crater on May 24, 2009 in East Java, Indonesia.
In this photo taken through a segment of a replacement ceramic pipe, workers are repairing a large sulfur condensation pipe. Ijen volcano complex May 24, 2009 in the vicinity of Banyuwangi, East Java, Indonesia.
A piece of sulfur extracted from the Ijen volcano. Photo taken on May 24, 2009, East Java, Indonesia.
A miner extracts sulfur from a pipe at the Ijen volcano crater on May 24, 2009 in East Java, Indonesia.
Baskets loaded with gray, ready to be carried up the steep crater walls and then to the weigh station. May 24, 2009.
A miner approaches the top of the crater wall along a well-worn path leading to the Kawah Ijen volcano on May 25, 2009 in East Java, Indonesia.
The photo shows how heavy the load is - its weight can reach up to 70 kg - this is noticeable in the compressed skin and muscles of the miner who carries sulfur to the weighing station on May 25, 2009.
A miner shows sores and scars from carrying sulfur from the Ijen volcano, May 24, 2009 in East Java, Indonesia.
The miner reaches the weighing station and hangs his load of sulfur on the scales. May 25, 2009 in East Java, Indonesia.
The miner rests at the base camp, which is called "Camp Sulfutara". May 24, 2009 in Indonesia.
Sulfur is known in nature in several polymorphic crystalline modifications, in colloidal secretions, in liquid and gaseous states. IN natural conditions a stable modification is rhombic sulfur (α-sulfur). At atmospheric pressure at temperatures above 95.6°, α-sulfur transforms into monoclinic β-sulfur, and upon cooling it again becomes orthorhombic. γ-sulfur also crystallizes in the monoclinic system, is unstable at atmospheric pressure and transforms into α-sulfur. The structure of γ-sulfur has not been studied; It is conditionally classified in this structural group.
The article discusses several polymorphic modifications of sulfur: α-sulfur, β-sulfur, γ-sulfur
α-modification
The English name of the mineral α-sulphur is α-Sulрhur
origin of name
The name α-sulfur was introduced by Dana (1892).
Synonyms:
Rhombic sulfur. Usually simply called sulfur. Dayton-sulfur (Suzuki, 1915) is a pseudomorph of α-sulfur to β-sulfur.
Formula
Chemical composition
Often native sulfur is almost pure. Sulfur of volcanic origin often contains small amounts of As, Se, Te and traces of Ti. The sulfur of many deposits is contaminated with bitumen, clay, various sulfates and carbonates. It contains inclusions of gases and liquid containing a mother solution with NaCl, CaCl, Na2SO4, etc. Sometimes it contains up to 5.18% Se (selenium sulfur)
Varieties
1. Volkanite- (selenium sulfur) orange-red, red-brown color.
Crystallographic characteristics
Syngony. Rhombic.
Class. Dipyramidal. Some authors believed that sulfur crystallizes into the rhombic-tetrahedral class because it sometimes has the appearance of sphenoids, but this form, according to Royer, is explained by the influence of the asymmetric environment (active hydrocarbons) on the growth of crystals.
Crystal structure of sulfur
The structure of sulfur is molecular: 8 atoms in the lattice form one molecule. The sulfur molecule forms eight-ring rings in which atoms alternate on two levels (along the axis of the ring). 4 S atoms of the same level form a square rotated by 45° relative to another square. The planes of the squares are parallel to the c axis. The centers of the rings are located in the rhombic cell according to the “diamond” law: at the vertices and centers of the faces of the face-centered cell and at the centers of four of the eight octants into which the elementary cell is divided. The structure of sulfur follows the Hume-Rothery principle, which requires coordination 2 (= 8 - 6) for elements of the Mendeleev group V1b. In the structure of tellurium - selenium, as well as in monoclinic sulfur, this is achieved by a spiral arrangement of atoms, in the structure of orthorhombic sulfur (as well as synthetic β-selenium and β-tellurium) - by their ring arrangement. The S - S distance in the ring is 2.10 A, which is exactly the same as the S - S distance in the S 2 radical of pyrite (and covellite) and slightly larger S-S distances between S atoms from different rings (3.3 A).
Form of being in nature
Crystal Appearance
The appearance of the crystals is different - bipyramidal, less often thick-tabular along the (001) side, disphenoidal, etc. On the (111) faces, natural etching figures are observed that are absent on the (113) faces.
Doubles
Twins at (101), (011), (110) or (111) are rare; twins at (211) are also observed.
Aggregates. Solid masses, spherical and kidney-shaped discharges, stalactites and stalagmites, powdery deposits and crystals.
Physical properties
Optical
- The color is sulfur-yellow, straw- and honey-yellow, yellow-brown, reddish, greenish, gray due to impurities; sometimes the color is brown or almost black due to bitumen impurities.
- The line is colorless.
- Diamond shine
- The cast is resinous to greasy.
- Transparency. Transparent to translucent.
Mechanical
- Hardness 1-2. Fragile.
- Density 2.05-2.08.
- Cleavage along (001), (110), (111) is imperfect. Separate by (111).
- The fracture is conchoidal to uneven.
Chemical properties
Dissolves in carbon disulfide, turpentine, kerosene.
Other properties
Electrical conductivity at ordinary temperatures is almost zero. By friction sulfur electrified negatively. IN ultraviolet rays the 2 mm thick plate is opaque. At atmospheric pressure, melting temperature. 112.8°; boiling point + 444.5°. Melting heat at 115° 300 cal/g-atom. Heat of vaporization at 316° 11600 cal/g-atom. At atmospheric pressure at 95.6°, α-sulfur transforms into β-sulfur with increasing volume.
Artificial acquisition
Obtained by sublimation or crystallization from solution.
Diagnostic signs
Easily recognized by yellow color, fragility, shine and ease of ignition.
Associated minerals. Gypsum, anhydrite, opal, jarosite, asphalt, petroleum, ozokerite, hydrocarbon gas, hydrogen sulfide, celestine, halite, calcite, aragonite, barite, pyrite.
Origin and occurrence in nature
Native sulfur is found only in the very top of the earth's crust. Formed through a variety of processes.
Animals play a major role in the formation of sulfur deposits. plant organisms, on the one hand, as S batteries, and on the other, as promoting the decomposition of H 2 S and other sulfur compounds. The formation of sulfur in waters, silts, soils, swamps and oils is associated with the activity of bacteria; in the latter it is partly contained in the form of colloidal particles. Sulfur can be released from waters containing H 2 S under the influence of atmospheric oxygen. In coastal areas, sulfur sometimes falls out when fresh water mixes with salt water (from H 2 S sea water, under the influence of oxygen dissolved in fresh waters). From some natural waters sulfur is released in the form of white turbidity (the Molochnaya river in the Kuibyshev region, etc.). From the waters of sulfur springs and from swamp waters containing H 2 S and S, sulfur falls into northern regions Russia in winter period during the freezing process. The main source of sulfur formation in many deposits is, in one way or another, H 2 S, whatever its origin.
Significant accumulations of sulfur are observed in volcanic areas, in the oxidation zone of some deposits and among sedimentary strata; deposits of the latter group serve as the main sources of native sulfur mined for practical purposes. In volcanic areas, sulfur is released both during volcanic eruptions and from fumaroles, solfataras, hot springs and gas jets. Sometimes a molten mass of sulfur pours out of a volcano crater in the form of a stream (in Japan), and β- or γ-sulfur is first formed, which later turns into α-sulfur with a characteristic granular structure. During volcanic eruptions, sulfur mainly arises from the action of released H 2 S on sulfur dioxide or from the oxidation of hydrogen sulfide by atmospheric oxygen; it can also sublimate with water vapor. S vapors can be captured by fumarole gases and jets of carbon dioxide. Observed for the first time in the stages of volcanic eruptions, the blue flame represents clouds of burning sulfur (Vulcano, on the Aeolian Islands, Italy). The hydrogen sulfide stage of fumaroles and solfataras, accompanied by the formation of native sulfur, follows the stage of release of fluoride and chloride compounds and precedes the stage of carbon dioxide emissions. Sulfur is released from solfataras in the form of loose tuff-like products, which are easily transported by wind and precipitation, forming secondary deposits (Cow Creek, Utah in the USA). 
Sulfur. Crystals in plaster
Mineral Change
In the earth's crust native sulfur easily oxidizes to form sulfuric acid and various sulfates; under the influence of bacteria can also produce hydrogen sulfide.
Place of Birth
Sulfur deposits of volcanic origin are usually small; they are found in Kamchatka (fumaroles), on Mount Alagez in Armenia, in Italy (solfatars of Slit Pozzuoli), in Iceland, Mexico, Japan, the USA, Java, the Aeolian Islands, etc.
The release of sulfur in hot springs is accompanied by the deposition of opal, CaCO 3, sulfates, etc. In some places, sulfur replaces limestone near hot springs, and is sometimes released in the form of a very fine turbidity. Hot springs depositing sulfur are observed in volcanic areas and in areas of young tectonic disturbances, for example, in Russia - the Caucasus, in Central Asia, on Far East, on the Kuril Islands; in the USA - in Yellowstone national park, in California; in Italy, Spain, Japan, etc.
Often native sulfur is formed during the process of hypergene changes during the decomposition of sulfide minerals (pyrite, marcasite, melnikovite, galena, stibnite, etc.). Quite large accumulations were found in the oxidation zone of pyrite deposits, for example, in the Stalin deposit in the Sverdlovsk region. and in the Blavinskoye field of the Orenburg region; in the latter, the sulfur appears as a dense but brittle mass with a layered texture, different colors. In the Maykain deposit Pavlodar region(Kazakhstan) large accumulations of native sulfur were observed between the jarosite zone and the pyrite ore zone.
Native sulfur is found in small quantities in the oxidation zone of many deposits. It is known that sulfur is formed in connection with coal fires during spontaneous combustion of pyrite or marcasite (powdery sulfur in a number of deposits in the Urals), and during fires in oil shale deposits (for example, in California).
In black sea mud, sulfur is formed when it turns gray in air due to the change in the monosulphide of iron contained in it.
The largest commercial sulfur deposits are found among sedimentary rocks, mainly of Tertiary or Permian age. Their formation is associated with the reduction of sulfur from sulfates, mainly gypsum, less often anhydrite. The origin of sulfur in sedimentary formations is controversial. Gypsum under the influence organic compounds, bacteria, free hydrogen, etc. is reduced first, possibly to CaS or Ca(HS) 2, which, under the influence of carbon dioxide and water, transform into calcite with the release of hydrogen sulfide; the latter, when reacting with oxygen, produces sulfur. Accumulations of sulfur in sedimentary strata sometimes have a sheet-like character. They are often associated with salt domes. In these deposits, sulfur is accompanied by asphalt, oil, ozokerite, gaseous hydrocarbons, hydrogen sulfide, celestine, halite, calcite, aragonite, barite, pyrite and other minerals. Pseudomorphoses of sulfur are known from fibrous gypsum (selenite). In Russia, deposits of this type are available in the region Middle Volga(Syukeevskoye Tatarstan, Alekeyevskoye, Vodinskoye Samara region, etc.), in Turkmenistan (Gaurdak, Karakum), in the Ural-Embensky region of Kazakhstan, where a number of deposits are confined to salt domes, in Dagestan (Avar and Makhachkala groups) and in other areas.
Outside Russia large deposits sulfur associated with sedimentary strata are found in Italy (Sicily, Romagna), the USA (Louisiana and Texas), Spain (near Cadiz) and other countries.