Abstract on the topic:

Iron sulfides (FeS, FeS2 ) and calcium (CaS)

Completed by Ivanov I.I.

Introduction

Properties

Origin (genesis)

Sulfides in nature

Properties

Origin (genesis)

Spreading

Application

Pyrrhotite

Properties

Origin (genesis)

Application

Marcasite

Properties

Origin (genesis)

Place of Birth

Application

Oldhamite

Receipt

Physical properties

Chemical properties

Application

Chemical weathering

Thermal analysis

Thermogravimetry

Derivatography

Derivatographic analysis of pyrite

Sulfides

Sulfides are natural sulfur compounds of metals and some nonmetals. Chemically, they are considered as salts of hydrosulfide acid H2S. A number of elements form polysulfides with sulfur, which are salts of polysulfurous acid H2Sx. The main elements forming sulfides are Fe, Zn, Cu, Mo, Ag, Hg, Pb, Bi, Ni, Co, Mn, V, Ga, Ge, As, Sb.

Properties

The crystal structure of sulfides is due to the densest cubic and hexagonal packing of S2- ions, between which metal ions are located. The main structures are represented by coordination (galena, sphalerite), island (pyrite), chain (stibdenite) and layered (molybdenite) types.

The following general physical properties are characteristic: metallic luster, high and medium reflectivity, relatively low hardness and high specific gravity.

Origin (genesis)

Widely distributed in nature, accounting for about 0.15% of the mass of the earth's crust. The origin is predominantly hydrothermal; some sulfides are also formed during exogenous processes in a reducing environment. They are ores of many metals: Cu, Ag, Hg, Zn, Pb, Sb, Co, Ni, etc. The class of sulfides includes antimonides, arsenides, selenides and tellurides, which are similar in properties.

Sulfides in nature

Under natural conditions, sulfur occurs in two valence states of the S2 anion, which forms S2- sulfides, and the S6+ cation, which is part of the S04 sulfate radical.

As a result, the migration of sulfur in the earth's crust is determined by the degree of its oxidation: a reducing environment promotes the formation of sulfide minerals, and oxidizing conditions promote the formation of sulfate minerals. Neutral atoms of native sulfur represent a transition link between two types of compounds, depending on the degree of oxidation or reduction.

Pyrite

Pyrite is a mineral, iron disulfide FeS2, the most common sulfide in the earth's crust. Other names for the mineral and its varieties: cat's gold, fool's gold, iron pyrite, marcasite, bravoite. The sulfur content is usually close to theoretical (54.3%). Often there are impurities of Ni, Co (a continuous isomorphic series with CoS; usually cobalt pyrite contains from tenths of a percent to several percent of Co), Cu (from tenths of a percent to 10%), Au (usually in the form of tiny inclusions of native gold), As (up to several%), Se, Tl (~ 10-2%), etc.

Properties

The color is light brassy and golden yellow, reminiscent of gold or chalcopyrite; sometimes contains microscopic gold inclusions. Pyrite crystallizes in the cubic system. Crystals in the form of a cube, pentagon-dodecahedron, less often octahedron, are also found in the form of massive and granular aggregates.

Hardness on the mineralogical scale is 6 - 6.5, density 4900-5200 kg/m3. On the Earth's surface, pyrite is unstable, easily oxidized by atmospheric oxygen and groundwater, turning into goethite or limonite. The shine is strong, metallic.

Origin (genesis)

Installed in almost all types of geological formations. It is present in igneous rocks as an accessory mineral. Typically an essential component in hydrothermal veins and metasomatic deposits (high, medium and low temperature). In sedimentary rocks, pyrite occurs in the form of grains and nodules, such as black shales, coals and limestones. Sedimentary rocks are known, consisting mainly of pyrite and flint. Often forms pseudomorphs on fossil wood and ammonites.

Spreading

Pyrite is the most common sulfide class mineral in the earth's crust; found most often in deposits of hydrothermal origin, pyrite deposits. The largest industrial accumulations of pyrite ores are located in Spain (Rio Tinto), the USSR (Ural), Sweden (Buliden). Occurs as grains and crystals in metamorphic schists and other iron-bearing metamorphic rocks. Pyrite deposits are developed primarily to extract the impurities it contains: gold, cobalt, nickel, and copper. Some pyrite-rich deposits contain uranium (Witwatersrand, South Africa). Copper is also extracted from massive sulfide deposits in Ducktown (Tennessee, USA) and in the valley of the river. Rio Tinto (Spain). If a mineral contains more nickel than iron, it is called bravoite. When oxidized, pyrite turns into limonite, so buried pyrite deposits can be detected by limonite (iron) caps on the surface. Main deposits: Russia, Norway, Sweden, France, Germany, Azerbaijan, USA.

Application

Are pyrite ores one of the main types of raw materials used to produce sulfuric acid?

Iron(II) sulfide
Iron(II)-sulfide-unit-cell-3D-balls.png
Are common
Systematic Name	Iron(II) sulfide
Chem. formula	FeS
Physical properties
State	hard
Molar mass	87.910 g/mol
Density	4.84 g/cm³
Thermal properties
T. float.	1194 °C
Classification
Reg. CAS number	1317-37-9
SMILES
Data are based on standard conditions (25 °C, 100 kPa) unless otherwise stated.

Description and structure

Receipt

$\backslash mathsf(Fe\; +\; S\; \backslash longrightarrow\; FeS)$

The reaction begins when a mixture of iron and sulfur is heated in a burner flame, and can then proceed without heating, releasing heat.

$\backslash mathsf(Fe\_2O\_3\; +\; H\_2\; +\; 2H\_2S\; \backslash longrightarrow\; 2FeS\; +\; 3H\_2O)$

Chemical properties

1. Interaction with concentrated HCl:

$\backslash mathsf(FeS\; +\; 2HCl\; \backslash longrightarrow\; FeCl\_2\; +\; H\_2S)$

2. Interaction with concentrated HNO 3:

$\backslash mathsf(FeS\; +\; 12HNO\_3\; \backslash longrightarrow\; Fe(NO\_3)\_2\; +\; H\_2SO\_4\; +\; 9NO\_2\; +\; 5H\_2O)$

Application

Iron(II) sulfide is a common starting material in the laboratory production of hydrogen sulfide. Iron hydrosulfide and/or its corresponding basic salt is the most important component of some medicinal muds.

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Notes

Literature

• Lidin R. A. “Handbook for schoolchildren. Chemistry" M.: Astrel, 2003.
• Nekrasov B.V. Fundamentals of general chemistry. - 3rd edition. - Moscow: Chemistry, 1973. - T. 2. - P. 363. - 688 p.

Links

Excerpt characterizing iron(II) sulfide

She stopped again. No one interrupted her silence.
- Our grief is common, and we will divide everything in half. “Everything that is mine is yours,” she said, looking around at the faces standing in front of her.
All eyes looked at her with the same expression, the meaning of which she could not understand. Whether it was curiosity, devotion, gratitude, or fear and distrust, the expression on all faces was the same.
“Many people are pleased with your mercy, but we don’t have to take the master’s bread,” said a voice from behind.
- Why not? - said the princess.
No one answered, and Princess Marya, looking around the crowd, noticed that now all the eyes she met immediately dropped.
- Why don’t you want to? – she asked again.
Nobody answered.
Princess Marya felt heavy from this silence; she tried to catch someone's gaze.
- Why don’t you talk? - the princess turned to the old man, who, leaning on a stick, stood in front of her. - Tell me if you think anything else is needed. “I’ll do everything,” she said, catching his gaze. But he, as if angry at this, lowered his head completely and said:
- Why agree, we don’t need bread.
- Well, should we give it all up? Do not agree. We don’t agree... We don’t agree. We feel sorry for you, but we do not agree. Go on your own, alone...” was heard in the crowd from different directions. And again the same expression appeared on all the faces of this crowd, and now it was probably no longer an expression of curiosity and gratitude, but an expression of embittered determination.
“You didn’t understand, right,” said Princess Marya with a sad smile. - Why don’t you want to go? I promise to house you and feed you. And here the enemy will ruin you...
But her voice was drowned out by the voices of the crowd.
“We don’t have our consent, let him ruin it!” We don’t take your bread, we don’t have our consent!
Princess Marya again tried to catch someone's gaze from the crowd, but not a single glance was directed at her; the eyes obviously avoided her. She felt strange and awkward.
- See, she taught me cleverly, follow her to the fortress! Destroy your home and go into bondage and go. Why! I'll give you the bread, they say! – voices were heard in the crowd.
Princess Marya, lowering her head, left the circle and went into the house. Having repeated the order to Drona that there should be horses for departure tomorrow, she went to her room and was left alone with her thoughts.

For a long time that night, Princess Marya sat at the open window in her room, listening to the sounds of men talking coming from the village, but she did not think about them. She felt that no matter how much she thought about them, she could not understand them. She kept thinking about one thing - about her grief, which now, after the break caused by worries about the present, had already become past for her. She could now remember, she could cry and she could pray. As the sun set, the wind died down. The night was quiet and fresh. At twelve o'clock the voices began to fade, the rooster crowed, the full moon began to emerge from behind the linden trees, a fresh, white mist of dew rose, and silence reigned over the village and over the house.

Abstract on the topic:

Iron sulfides ( FeS , FeS 2 ) and calcium ( CaS )

Completed by Ivanov I.I.

Introduction

Properties

Origin (genesis)

Sulfides in nature

Properties

Origin (genesis)

Spreading

Application

Pyrrhotite

Properties

Origin (genesis)

Application

Marcasite

Properties

Origin (genesis)

Place of Birth

Application

Oldhamite

Receipt

Physical properties

Chemical properties

Application

Chemical weathering

Thermal analysis

Thermogravimetry

Derivatography

Derivatographic analysis of pyrite

Sulfides

Sulfides are natural sulfur compounds of metals and some non-metals. Chemically, they are considered as salts of hydrosulfide acid H 2 S. A number of elements form polysulfides with sulfur, which are salts of polysulfur acid H 2 S x. The main elements that form sulfides are Fe, Zn, Cu, Mo, Ag, Hg, Pb, Bi, Ni, Co, Mn, V, Ga, Ge, As, Sb.

Properties

The crystalline structure of sulfides is due to the densest cubic and hexagonal packing of S 2- ions, between which metal ions are located. The main structures are represented by coordination (galena, sphalerite), island (pyrite), chain (stibdenite) and layered (molybdenite) types.

The following general physical properties are characteristic: metallic luster, high and medium reflectivity, relatively low hardness and high specific gravity.

Origin (genesis)

Widely distributed in nature, accounting for about 0.15% of the mass of the earth's crust. The origin is predominantly hydrothermal; some sulfides are also formed during exogenous processes in a reducing environment. They are ores of many metals - Cu, Ag, Hg, Zn, Pb, Sb, Co, Ni, etc. The class of sulfides includes antimonides, arsenides, selenides and tellurides, which are similar in properties.

Sulfides in nature

Under natural conditions, sulfur occurs in two valence states of the S 2 anion, which forms S 2- sulfides, and the S 6+ cation, which is part of the S0 4 sulfate radical.

As a result, the migration of sulfur in the earth's crust is determined by the degree of its oxidation: a reducing environment promotes the formation of sulfide minerals, and oxidizing conditions promote the formation of sulfate minerals. Neutral atoms of native sulfur represent a transition link between two types of compounds, depending on the degree of oxidation or reduction.

Pyrite

Pyrite is a mineral, iron disulfide FeS 2, the most common sulfide in the earth's crust. Other names for the mineral and its varieties: cat's gold, fool's gold, iron pyrite, marcasite, bravoite. The sulfur content is usually close to theoretical (54.3%). Often there are impurities of Ni, Co (a continuous isomorphic series with CoS; usually cobalt pyrite contains from tenths of a percent to several percent of Co), Cu (from tenths of a percent to 10%), Au (usually in the form of tiny inclusions of native gold), As (up to several%), Se, Tl (~ 10-2%), etc.

Properties

The color is light brassy and golden yellow, reminiscent of gold or chalcopyrite; sometimes contains microscopic gold inclusions. Pyrite crystallizes in the cubic system. Crystals in the form of a cube, pentagon-dodecahedron, less often - octahedron, are also found in the form of massive and granular aggregates.

Hardness on the mineralogical scale is 6 - 6.5, density 4900-5200 kg/m3. On the Earth's surface, pyrite is unstable, easily oxidized by atmospheric oxygen and groundwater, turning into goethite or limonite. The shine is strong, metallic.

Origin (genesis)

Installed in almost all types of geological formations. It is present in igneous rocks as an accessory mineral. Typically an essential component in hydrothermal veins and metasomatic deposits (high, medium and low temperature). In sedimentary rocks, pyrite occurs in the form of grains and nodules, such as black shales, coals and limestones. Sedimentary rocks are known, consisting mainly of pyrite and flint. Often forms pseudomorphs on fossil wood and ammonites.

Spreading

Pyrite is the most common sulfide class mineral in the earth's crust; found most often in deposits of hydrothermal origin, pyrite deposits. The largest industrial accumulations of pyrite ores are located in Spain (Rio Tinto), the USSR (Ural), Sweden (Buliden). Occurs as grains and crystals in metamorphic schists and other iron-bearing metamorphic rocks. Pyrite deposits are developed primarily to extract the impurities it contains: gold, cobalt, nickel, and copper. Some pyrite-rich deposits contain uranium (Witwatersrand, South Africa). Copper is also extracted from massive sulfide deposits in Ducktown (Tennessee, USA) and in the valley of the river. Rio Tinto (Spain). If a mineral contains more nickel than iron, it is called bravoite. When oxidized, pyrite turns into limonite, so buried pyrite deposits can be detected by limonite (iron) caps on the surface. Main deposits: Russia, Norway, Sweden, France, Germany, Azerbaijan, USA.

Application

Pyrite ores are one of the main types of raw materials used to produce sulfuric acid and copper sulfate. Non-ferrous and precious metals are simultaneously extracted from it. Due to its ability to produce sparks, pyrite was used in the wheel locks of the first shotguns and pistols (steel-pyrite pair). Valuable collectible material.

Pyrrhotite

Properties

Pyrrhotite is fiery red or dark orange in color, magnetic pyrite, a mineral from the class of sulfides with the composition Fe 1-x S. Ni and Co are included as impurities. The crystal structure has a dense hexagonal packing of S atoms.

The structure is defective because not all octahedral voids are occupied by Fe, due to which some of the Fe 2+ has passed into Fe 3+. The structural deficiency of Fe in pyrrhotite is different: it gives compositions from Fe 0.875 S (Fe 7 S 8) to FeS (stoichiometric composition FeS - troilite). Depending on Fe deficiency, the parameters and symmetry of the crystal cell change, and at x~0.11 and below (up to 0.2) pyrotine changes from a hexagonal modification to a monoclinic one. The color of pyrrhotite is bronze-yellow with brown tarnish; metallic shine. In nature, continuous masses and granular secretions are common, consisting of germinations of both modifications.

Hardness on the mineralogical scale 3.5-4.5; density 4580-4700 kg/m3. Magnetic properties vary depending on the composition: hexagonal (S-poor) pyrrhotites are paramagnetic, monoclinic (S-rich) are ferromagnetic. Individual pyrotine minerals have a special magnetic anisotropy - paramagnetism in one direction and ferromagnetism in another, perpendicular to the first.

Origin (genesis)

Pyrrhotite is formed from hot solutions with a decrease in the concentration of dissociated S 2- ions.

It is widespread in hypogene deposits of copper-nickel ores associated with ultramafic rocks; also in contact-metasomatic deposits and hydrothermal bodies with copper-polymetallic, sulfide-cassiterite and other mineralization. In the oxidation zone it transforms into pyrite, marcasite and brown iron ores.

Application

Plays an important role in the production of iron sulfate and crocus; As an ore for obtaining iron, it is less significant than pyrite. It is used in the chemical industry (production of sulfuric acid). Pyrrhotite usually contains impurities of various metals (nickel, copper, cobalt, etc.), which makes it interesting from the point of view of industrial use. First, this mineral is an important iron ore. And secondly, some of its varieties are used as nickel ore... Valued by collectors.

Marcasite

The name comes from the Arabic "marcasitae", which alchemists used to designate sulfur compounds, including pyrite. Another name is “radiant pyrite”. Named spectropyrite for its resemblance to pyrite in color and iridescent tarnish.

Marcasite, like pyrite, is iron sulfide - FeS2, but differs from it in its internal crystalline structure, greater fragility and less hardness. Crystallizes in the rhombic system. Marcasite is opaque, has a brass-yellow color, often with a greenish or grayish tint, and occurs in the form of tabular, needle-shaped and lance-shaped crystals that can form beautiful star-shaped radial-radiant intergrowths; in the form of spherical nodules (from the size of a nut to the size of a head), sometimes sintered, kidney-shaped and grape-shaped formations, crusts. Often replaces organic remains, such as ammonite shells.

Properties

The color of the line is dark, greenish-gray, the luster is metallic. Hardness 5-6, brittle, imperfect cleavage. Marcasite is not very stable in surface conditions, and over time, especially in high humidity, it decomposes, turning into limonite and releasing sulfuric acid, so it should be stored separately and with extreme care. When struck, marcasite emits sparks and a sulfur odor.

Origin (genesis)

In nature, marcasite is much less common than pyrite. It is observed in hydrothermal, predominantly vein deposits, most often in the form of druses of small crystals in voids, in the form of powders on quartz and calcite, in the form of crusts and sinter forms. In sedimentary rocks, mainly coal-bearing, sandy-clay deposits, marcasite is found mainly in the form of concretions, pseudomorphs from organic remains, as well as fine sooty matter. Based on its macroscopic features, marcasite is often mistaken for pyrite. In addition to pyrite, sphalerite, galena, chalcopyrite, quartz, calcite and others are usually found in association with marcasite.

Place of Birth

Among the hydrothermal sulfide deposits, one can note Blyavinskoye in the Orenburg region in the Southern Urals. Sedimentary deposits include the Borovichekiye coal-bearing deposits of sandy clays (Novgorod region), containing nodules of various forms. The Kuryi-Kamensky and Troitsko-Bainovsky deposits of clayey deposits on the eastern slope of the Middle Urals (east of Sverdlovsk) are also famous for their diversity of forms. Of note are deposits in Bolivia, as well as Clausthal and Freiberg (Westphalia, North Rhine, Germany), where well-formed crystals are found. In the form of nodules or especially beautiful, radially radiant flat lenses in once silty sedimentary rocks (clays, marls and brown coals), deposits of marcasite are found in Bohemia (Czech Republic), the Paris Basin (France) and Styria (Austria, samples up to 7 cm). Marcasite is mined at Folkestone, Dover and Tevistock in the UK, in France, and in the US excellent examples are obtained from Joplin and other places in the Tri-State mining region (Missouri, Oklahoma and Kansas).

Application

If large masses are available, marcasite can be developed for the production of sulfuric acid. A beautiful but fragile collectible.

Oldhamite

Calcium sulfide, calcium sulfide, CaS - colorless crystals, density 2.58 g/cm3, melting point 2000 °C.

Receipt

Known as the mineral Oldhamite, consisting of calcium sulfide with impurities of magnesium, sodium, iron, and copper. The crystals are pale brown, turning to dark brown.

Direct synthesis from elements:

The reaction of calcium hydride in hydrogen sulfide:

From calcium carbonate:

Reduction of calcium sulfate:

Physical properties

White crystals, face-centered cubic lattice of the NaCl type (a = 0.6008 nm). When melted, it decomposes. In a crystal, each S 2- ion is surrounded by an octahedron consisting of six Ca 2+ ions, while each Ca 2+ ion is surrounded by six S 2- ions.

Slightly soluble in cold water, does not form crystalline hydrates. Like many other sulfides, calcium sulfide undergoes hydrolysis in the presence of water and has the smell of hydrogen sulfide.

Chemical properties

When heated, it decomposes into components:

In boiling water it completely hydrolyzes:

Dilute acids displace hydrogen sulfide from salt:

Concentrated oxidizing acids oxidize hydrogen sulfide:

Hydrogen sulfide is a weak acid and can be displaced from salts even by carbon dioxide:

With an excess of hydrogen sulfide, hydrosulfides are formed:

Like all sulfides, calcium sulfide is oxidized by oxygen:

Application

It is used for the preparation of phosphors, as well as in the leather industry for removing hair from skins, and is also used in the medical industry as a homeopathic remedy.

Chemical weathering

Chemical weathering is a combination of various chemical processes, as a result of which further destruction of rocks occurs and a qualitative change in their chemical composition with the formation of new minerals and compounds. The most important factors in chemical weathering are water, carbon dioxide and oxygen. Water is an energetic solvent of rocks and minerals.

Reactions that occur when iron sulfide is roasted in oxygen:

4FeS + 7O 2 → 2Fe 2 O 3 + 4SO 2

Reactions that occur when iron disulfide is roasted in oxygen:

4FeS 2 + 11O 2 → 2Fe 2 O 3 + 8SO 2

When pyrite is oxidized under standard conditions, sulfuric acid is formed:

2FeS 2 +7O 2 +H 2 O→2FeSO 4 +H 2 SO 4

When calcium sulfide enters the firebox, the following reactions may occur:

2CaS + 3O 2 → 2CaO + 2SO 2

CaO + SO 2 + 0.5O 2 → CaSO 4

with the formation of calcium sulfate as the final product.

When calcium sulfide reacts with carbon dioxide and water, calcium carbonate and hydrogen sulfide are formed:

5-second activation of pyrite leads to a noticeable increase in the ectotherm area, a decrease in the temperature range of oxidation and greater mass loss upon heating. Increasing the treatment time in the furnace to 30 s causes stronger transformations of pyrite. The configuration of the DTA curves and the direction of the TG curves change noticeably, and the oxidation temperature ranges continue to decrease. A kink appears in the differential heating curve corresponding to a temperature of 345 º C, which is associated with the oxidation of iron sulfates and elemental sulfur, which are products of mineral oxidation. The appearance of the DTA and TG curves of a mineral sample treated for 5 minutes in an oven differs significantly from the previous ones. The new clearly defined exothermic effect on the differential heating curve with a temperature of approximately 305 º C should be attributed to the oxidation of new formations in the temperature range 255 - 350 º C. The fact that the fraction obtained as a result of 5-minute activation is a mixture of phases.

FeS monosulfide - brown or black crystals; nonstoichiometric conn., at 743 °C, the homogeneity region is 50-55.2 at. % S. Exists in several. crystalline modifications - a", a:, b, d (see table); transition temperature a": b 138 °C, DH 0 transition 2.39 kJ/mol, transition temperature b: d 325 °C , DH 0 transition 0.50 kJ/mol; m.p. 1193°С (FeS with S content 51.9 at.%), DH 0 pl 32.37 kJ/mol; dense 4.79 g/cm3; for a-FeS (50 at.% S): C 0 p 50.58 J/(mol. K); DH 0 arr -100.5 kJ/mol, DG 0 arr -100.9 kJ/mol; S 0 298 60.33 J/(mol. K). When heated in a vacuum above ~ 700 °C, it splits off S, dissociation pressure logp (in mm Hg) = H 15695/T + 8.37. Modification d is paramagnetic, a", b and a: - antiferromagnetic, solid solutions or ordered structures with an S content of 51.3-53.4 at.% - ferro- or ferrimagnetic. Practically insoluble in water (6.2.10 - 4% by weight), decomposes in diluted compounds with the release of H 2 S. In air, wet FeS is easily oxidized to FeSO 4. It is found in nature in the form of the minerals pyrrhotite (magnetic pyrite FeS 1 _ 1.14) and troilite ( in meteorites) Obtained by heating Fe with S at ~600°C, by the action of H 2 S (or S) on Fe 2 O 3 at 750-1050 ° C, by mixing alkali metal sulfides or ammonium with Fe(II) salts in aqueous solution. Used to produce H 2 S; pyrrhotite can also be used for the concentration of non-ferrous metals. FeS 2 disulfide - golden yellow crystals with a metallic luster; homogeneity range ~ 66.1-66.7 at. % S. Exists in two modifications: rhombic (in nature, the mineral marcasite, or radiant pyrite) with a density of 4.86 g/cm 3 and cubic (mineral pyrite, or iron or sulfur pyrite) with a density of 5.03 g/cm cm, transition temperature marcasite: pyrite 365 °C; m.p. 743 °C (incongruent). For pyrite: C 0 p 62.22 J/(mol K); DH 0 arr - 163.3 kJ/mol, DG 0 arr -151.94 kJ/mol; S 0 298 52.97 J/(mol. K); has the properties of a semiconductor, the band gap is 1.25 eV. DH 0 sample of marcasite H 139.8 kJ/mol. When heated in a vacuum dissociates into pyrrhotite and S. Practically insoluble. in water, decomposes HNO 3. In air or in O 2 it burns to form SO 2 and Fe 2 O 3. Obtained by calcination of FeCl 3 in a stream of H 2 S. Att. FeS 2 - raw materials for the production of S, Fe, H 2 SO 4, Fe sulfates, a charge component for the processing of manganese ores and concentrates; pyrite cinders are used in cast iron smelting; pyrite crystals - detectors in radio engineering.

J. s. Fe 7 S 8 exists in monoclinic and hexagonal modifications; stable up to 220 °C. Fe 3 S 4 sulfide (smithite mineral) - rhombohedral crystals. lattice. Fe 3 S 4 and Fe 2 S 3 are known. spinel-type gratings; low stability. Lit.: Samsonov G.V., Drozdova S.V., Sulfides, M., 1972, p. 169-90; Vanyukov A.V., Isakova R.A., Bystroe V.P., Thermal dissociation of metal sulfides, A.-A., 1978; Abishev D.N., Pashinkin A.S., Magnetic iron sulfides, A.-A., 1981. I. N. One.

• - Sesquisulfide Bi2S3 - gray crystals with metallic. glitter, diamond lattice...

  Chemical encyclopedia

• - Disulfide WS2 - dark gray crystals with a hexagon. grate; -203.0 kJ/mol...

  Chemical encyclopedia

• - Sulfide K2S - colorless. cubic crystals syngony; m.p. 948°C; dense 1.805 g/cm3; С°р 76.15 J/; DH0 arr -387.3 kJ/mol, DG0 arr -372 kJ/mol; S298 113.0 J/. Well sol. in water, undergoing hydrolysis, sol. in ethanol, glycerin...

  Chemical encyclopedia

• - compounds of sulfur with metals and certain non-metals. S. metals - salts of hydrosulfide acid H2S: medium acidic, or hydrosulfides. By firing natural materials, colors are obtained. metals and SO2...
• - a gland that produces one or more hormones and secretes them directly into the bloodstream. The endocrine gland lacks excretory ducts...

  Medical terms

• - FeS, FeS2, etc. Natural ferrous materials - pyrite, marcasite, pyrrhotite - Ch. an integral part of pyrites. Larks: 1 - forest; 2 - field; 3 - horned; 4 - crested...

  Natural science. encyclopedic Dictionary

• - chem. compounds of metals with sulfur. Mn. S. are natural minerals, for example pyrite, molybdenite, sphalerite...

  Big Encyclopedic Polytechnic Dictionary

• - R2S, are most easily obtained by adding dropwise a solution of diazo salts to an alkaline solution of thiophenol heated to 60-70°: C6H5-SH + C6H5N2Cl + NaHO = 2S + N2 + NaCl + H2O...

  Encyclopedic Dictionary of Brockhaus and Euphron

• - compounds of iron with sulfur: FeS, FeS2, etc. Natural iron sulfur. widespread in the earth's crust. See Natural sulfides, Sulfur....
• - sulfur compounds with more electropositive elements; can be considered as salts of hydrosulfide acid H2S...

  Great Soviet Encyclopedia

• - : FeS - FeS2, etc. Natural iron sulfides - pyrite, marcasite, pyrrhotite - the main component of pyrites...
• - sulfur compounds with metals and some non-metals. Metal sulfides are salts of hydrogen sulfide acid H2S: medium and acidic, or hydrosulfides. Non-ferrous metals and SO2 are obtained by roasting natural sulfides...

  Large encyclopedic dictionary

• - SULFIDES, -s, units. sulfide, -a, male . Chemical compounds of sulfur with metals and certain non-metals...

  Ozhegov's Explanatory Dictionary

• - sulfides plural. Compounds of sulfur with other elements...

  Explanatory Dictionary by Efremova

• - sulf"ides, -s, units of h. -f"...

  Russian spelling dictionary

• - Compounds of any body with sulfur, corresponding to oxides or acids...

  Dictionary of foreign words of the Russian language

"IRON SULFIDE" in books

Iron metabolism

From the book Biological Chemistry author Lelevich Vladimir Valeryanovich

Iron metabolism The adult human body contains 3–4 g of iron, of which about 3.5 g is found in the blood plasma. Hemoglobin of erythrocytes contains approximately 68% of the total iron in the body, ferritin - 27% (reserve iron of the liver, spleen, bone marrow), myoglobin

Iron transformations

From the book Metals that are always with you author Terletsky Efim Davidovich

Transformations of iron In a normal temperate climate, a healthy person requires 10-15 mg of iron per day in food. This amount is quite enough to cover its losses from the body. Our body contains from 2 to 5 g of iron, depending on the level

POOD OF IRON

From the book Before Sunrise author Zoshchenko Mikhail Mikhailovich

POUND OF IRON I'm busy disassembling my pencil case. I'm sorting through pencils and pens. I admire my small pocket knife. The teacher calls me. He says: “Answer, just quickly: what’s heavier, a pound of fluff or a pound of iron?” Seeing no catch in this, I, without thinking, answer: “Pound.”

Iron type

From the book Philosopher's Stone of Homeopathy author Simeonova Natalya Konstantinovna

Type of iron Scientific ideas about iron deficiency are reflected in the homeopathic medicinal pathogenesis of iron, which indicates that this remedy is suitable for thin, pale patients, often young anemic girls with skin as white as alabaster, with

Age of Iron

From the book History of Russia from ancient times to the beginning of the 20th century author Froyanov Igor Yakovlevich

Age of Iron But for the next era, we also know the names of those peoples who lived on the territory of our country. In the 1st millennium BC. e. The first iron tools appear. The most developed Early Iron cultures are known in the Black Sea steppes - they were abandoned

Age of Iron

From the book World History. Volume 3 Age of Iron author Badak Alexander Nikolaevich

Age of Iron This is an era in the primitive and early class history of mankind, characterized by the spread of iron metallurgy and the manufacture of iron tools. The idea of ​​three centuries: stone, bronze and iron - arose in the ancient world. This is good by the TSB author

Organic sulfides

TSB

Natural sulfides

From the book Great Soviet Encyclopedia (SU) by the author TSB

Antimony sulfides

From the book Great Soviet Encyclopedia (SU) by the author TSB

4. Semiotics of endocrine system disorders (pituitary gland, thyroid gland, parathyroid glands, adrenal glands, pancreas)

From the book Propaedeutics of Childhood Illnesses: Lecture Notes author Osipova O V

4. Semiotics of endocrine system disorders (pituitary gland, thyroid gland, parathyroid glands, adrenal glands, pancreas) Violation of the hormone-forming or hormone-releasing function of the pituitary gland leads to a number of diseases. For example, excess production

Age of Iron

From the book The Mystery of the Damask Pattern author Gurevich Yuri Grigorievich

Age of Iron Unlike silver, gold, copper and other metals, iron is rarely found in nature in its pure form, so it was mastered by man relatively late. The first samples of iron that our ancestors held in their hands were unearthly, meteorite