Iron oxides are. Iron oxides. Composition of dye E172 Iron oxides. Harm and properties of dye E172 E172 food additive

E-172 Iron oxides and hydroxides– food additive, dye.

Characteristic:

Iron oxides, inorganic pigments, are chemical compounds of iron and oxygen. Additive in the food industry E-172 used as a dye to color foods yellow, orange, red, brown and black. A total of 16 types of iron oxides and hydroxides are known. However, in the food industry, 3 forms of oxides are used to give products different shades: E-172(i) - Iron (II,III) oxide is a complex oxide that simultaneously contains iron (II) and iron (III) ions. It has the chemical formula Fe3O4 and occurs naturally as the mineral magnetite. Paints it black. E-172(ii) - Iron (III) oxide with the chemical formula Fe2O3. Occurs in nature as the mineral hematite. In common parlance - rust. Colors it red. E-172(iii) - Iron (II) oxide with the chemical formula FeO. Occurs in nature as the mineral wustite. Colors yellow. They are highly soluble in concentrated inorganic acids, insoluble in water, organic solvents, and vegetable oils. Very good resistance to light, heat and alkalis, good resistance to fruit acids. Iron oxides occur naturally, but are used in the food industry to produce additives E-172 They use the method of calcination of iron (II) and (III) oxides or by reacting iron with water vapor at high temperatures below 570°C.

Application:

Iron oxides and hydroxides widely distributed in nature and used by people in various fields of production. WEIGHT iron oxides and hydroxides (E-172) are approved for all QS foods. In the Russian Federation, the additive is allowed as a coloring agent in food products in accordance with technical regulations in quantities in accordance with technical regulations (clauses 3.2.14,3.11.3 SanPiN 2.3.2.1293-03). Iron oxides are used primarily for coloring dragees, decorations and coatings at a dosage of about 0.1 g/kg. In addition to the food industry, iron oxides are used:

• in the metallurgical industry as raw materials for the production of metals;
• in the paint and varnish industry as a pigment in paints and coatings;
• in the chemical industry as catalysts;
• in the cosmetics industry to give the desired shades to cosmetic products (for coloring eyelash dye, foundation, makeup and powder);
• in pharmaceuticals for the manufacture of medicines that increase hemoglobin levels, for coloring pharmaceuticals in the form of dragees, powders and creams. And iron oxides and hydroxides used for coloring toilet soap, as pigments in painting, colored cement, and as components of lining ceramics.

  Impact on the human body:

  Maximum permissible daily intake of the supplement E-172 is 0.5 mg/kg human body weight. In small doses, iron is beneficial for the body (increases hemoglobin levels in the blood). But with an overdose of iron, it can cause significant harm to health. When iron concentrations are high in the body, free radicals are produced, which can lead to heart attacks and strokes. In addition, the accumulation of iron in the liver provokes liver cancer, but this is typical for people with the genetic disease hemochromatosis. In a healthy body, subject to reasonable doses of iron intake, it does not cause any harm to the human body.

Iron(III) oxide

TU 6-09-1404-76

Fe2O3

Iron(III) oxide- a complex inorganic substance, a compound of iron and oxygen with the chemical formula Fe 2 O 3.

Iron(III) oxide is an amphoteric oxide with a high predominance of basic properties. Red-brown color. Thermally resistant to high temperatures. Formed when iron burns in air. Does not react with water. Reacts slowly with acids and alkalis. Reduced by carbon monoxide, molten iron. It fuses with oxides of other metals and forms double oxides - spinels.

Hematite is found in nature as a widespread mineral, the impurities of which cause the reddish color of laterite, red earths, and also the surface of Mars; another crystalline modification occurs as the mineral maghemite.

Iron oxide Fe 2 O 3 is crystals from red-brown to black-violet. The chemical is thermally stable. No reaction with water. Slow reaction with alkalis and acids.

Iron oxide Fe 2 O 3 is used as a raw material for the production of cast iron in the blast furnace process. This chemical is a catalyst in the ammonia manufacturing process. It is included in ceramics as one of the components; it is used in the manufacture of mineral paints and colored cements. Iron oxide Fe2O3 is effective for thermal welding of steel structural elements. This substance is associated with recording sound and images on magnetic media. Fe2O3 is a quality polishing agent for polishing steel and glass parts.

It is the main component of red lead. Fe 2 O 3 in the food industry is a fairly common food additive E172.

Fe 2 O 3 is used in the smelting of cast iron in the blast furnace process, a catalyst in the production of ammonia, a component of ceramics, colored cements and mineral paints, in thermite welding of steel structures, as a carrier of analog and digital information (for example, sound and image) on magnetic tapes (ferrimagnetic γ -Fe 2 O 3), as a polishing agent (red crocus) for steel and glass.

In the food industry it is used as a food coloring (E172).

In rocket modeling it is used to produce catalyzed caramel fuel, which has a burning rate 80% higher than conventional fuel.

It is the main component of red lead (kolkotar).

In the petrochemical industry it is used as a main component of a dehydrogenation catalyst in the synthesis of diene monomers.

Iron oxides are compounds of iron with oxygen.

The most famous are three iron oxides: iron oxide (II) - FeO, iron (III) oxide – Fe 2 O 3 and iron (II, III) oxide – Fe 3 O 4.

Iron(II) oxide

The chemical formula of ferrous oxide is FeO . This connection is black in color.

FeO Reacts easily with dilute hydrochloric acid and concentrated nitric acid.

FeO + 2HCl → FeCl 2 + H 2 O

FeO + 4HNO 3 → Fe(NO 3) 3 + NO 2 + 2H 2 O

It does not react with water or salts.

When interacting with hydrogen at a temperature of 350 o C and coke at a temperature above 1000 o C, it is reduced to pure iron.

FeO +H 2 → Fe + H 2 O

FeO +C → Fe + CO

Iron (II) oxide is obtained in different ways:

1. As a result of the reduction reaction of ferric oxide with carbon monoxide.

Fe 2 O 3 + CO → 2 FeO + CO 2

2. Heating iron with low oxygen pressure

2Fe + O 2 → 2 FeO

3. Decomposing ferrous oxalate in vacuum

FeC 2 O 4 → FeO +CO + CO 2

4. Interaction of iron with iron oxides at a temperature of 900-1000 o

Fe + Fe 2 O 3 → 3 FeO

Fe + Fe 3 O 4 → 4 FeO

In nature, ferrous oxide exists as the mineral wustite.

In industry it is used in the smelting of cast iron in blast furnaces, in the process of blackening (bluing) of steel. It is found in dyes and ceramics.

Iron(III) oxide

Chemical formula Fe2O3 . This is a compound of ferric iron with oxygen. It is a red-brown powder. Hematite is found in nature as a mineral.

Fe2O3 has other names: iron oxide, red lead, crocus, pigment red 101, food coloringE172 .

Does not react with water. Can interact with both acids and alkalis.

Fe 2 O 3 + 6HCl → 2 FeCl 3 + 3H 2 O

Fe 2 O 3 + 2NaOH → 2NaFeO 2 + H 2 O

Iron (III) oxide is used for painting building materials: brick, cement, ceramics, concrete, paving slabs, linoleum. It is added as a dye to paints and enamels, and to printing inks. Iron oxide is used as a catalyst in the production of ammonia. In the food industry it is known as E172.

Iron (II, III) oxide

Chemical formula Fe3O4 . This formula can be written in another way: FeO Fe 2 O 3.

It is found in nature as the mineral magnetite, or magnetic iron ore. It is a good conductor of electric current and has magnetic properties. Formed when iron burns and when superheated steam acts on iron.

3Fe + 2 O 2 → Fe 3 O 4

3Fe + 4H 2 O → Fe 3 O 4 + 4H 2

Heating at a temperature of 1538 o C leads to its disintegration

2Fe 3 O 4 → 6FeO + O 2

Reacts with acids

Fe 3 O 4 + 8HCl → FeCl 2 + 2FeCl 3 + 4H 2 O

Fe 3 O 4 + 10HNO 3 → 3Fe(NO 3) 3 + NO 2 + 5H 2 O

Reacts with alkalis upon fusion

Fe 3 O 4 + 14NaOH → Na 3 FeO 3 + 2Na 5 FeO 4 + 7H 2 O

Reacts with oxygen in the air

4 Fe 3 O 4 + O 2 → 6Fe 2 O 3

Reduction occurs by reaction with hydrogen and carbon monoxide

Fe 3 O 4 + 4H 2 → 3Fe + 4H 2 O

Fe 3 O 4 + 4CO → 3Fe +4CO 2

Magnetic nanoparticles of Fe 3 O 4 oxide have found application in magnetic resonance imaging. They are also used in the production of magnetic media. Iron oxide Fe 3 O 4 is included in paints that are produced specifically for warships, submarines and other equipment. Electrodes are made from fused magnetite for some electrochemical processes.

sulfuric: FeO + H 2 SO 4 = FeSO 4 + H 2 O nitric: 3FeO + 10HNO 3 = 3Fe(NO 3) 3 + NO + 5H 2 O Fe 2 O 3 + CO = 2FeO + CO 2

They are used in the production of magnetic storage media (magnetic tapes for audio, video and computer equipment, floppy disks, hard magnetic disk drives).

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See what “Iron oxides” are in other dictionaries:

IRON OXIDES: FeO Fe2O3 and Fe3O4. Natural iron oxides (hematite and magnetite) are raw materials for the production of iron. They are used in the production of magnetic materials, as pigments, components of lining ceramics... Big Encyclopedic Dictionary

IRON OXIDES: FeO, Fe2O3 and Fe3O4. Natural iron oxides (hematite and magnetite) are raw materials for the production of iron. They are used in the production of magnetic materials, as pigments, components of lining ceramics... encyclopedic Dictionary

IRON OXIDES- water-insoluble compounds FeO, Fe203 and their mixture Fe304 (in nature the mineral magnetite), which are used for the production of cast iron, steel, ferrites, etc. Big Polytechnic Encyclopedia

FeO, Fe2O3 and Fe3O4. Natural iron oxides (hematite and magnetite) are raw materials for the production of iron. They are used in the production of magnetic materials, as pigments, components of lining ceramics... encyclopedic Dictionary

Iron compounds insoluble in water: black FeO (obsolete ferrous oxide), tnl 1368 °C; black Fe2O3 (obsolete iron oxide, in nature the mineral magnetite), tnl 1538 °C; yellow, brown or dark red Fe3O4 (in nature the mineral is hematite or ... Big Encyclopedic Polytechnic Dictionary

FeO oxide (wüstite technique). In crystalline The wustite lattice has vacant sites, and its composition corresponds to FexO, where x = 0.89 0.95; Level of temperature dependence of decomposition pressure: log p(O2, in mmHg) = 26730/T+ 6.43 (T > 1813 K);… … Chemical encyclopedia

FeO, Fe2O3 and Fe3O4. Natural liquids (hematite and magnetite) raw materials for the production of iron. They are used in the production of magic materials, materials, as pigments, components of lining ceramics... Natural science. encyclopedic Dictionary

OXIDES: FeO (black, melting point 1369°C); Fe2O3 (from dark red to black violet or brown color, melting point 1565°C; mineral hematite, etc.); Fe3O4 (black, melting point 1594°C; magnetite mineral). Natural iron oxides are raw materials in the production of iron,... ... Modern encyclopedia

See Iron oxides... Chemical encyclopedia

IRON OXIDES, one of three compounds existing in three states: iron (II) oxide (ferrous oxide, FeO); iron(III) oxide (iron oxide, Fe2O3), which occurs naturally as HEMATITE; and ferrous oxide iron (Fe3O4), which... ... Scientific and technical encyclopedic dictionary

INTRODUCTION

This work is devoted to the study of the properties of iron (III) oxide Fe 2O 3, also known as minerals: hematite ( ?-Fe 2O 3), limonite (Fe 2O 3H2O), is part of magnetite (FeOFe2 O 3).

The topic of the course work is of practical and theoretical interest. The project will be useful for enterprises synthesizing Fe 2O 3on an industrial scale.

The project is also useful as a collection of information about iron, some of its oxides, iron (III) oxide in particular, and the minerals that contain it.

Goals that must be achieved upon completion of the project: collect the most complete information about iron (III) oxide, study its properties and methods of synthesis.

Project objectives:

Collect complete and up-to-date information on the topic.

Study the properties of iron and its oxide (III) Fe 2O 3, on the basis of which you can learn about the use of these substances.

In rocket modeling it is used to produce catalyzed caramel fuel, which has a burning rate 80% higher than conventional fuel.

It is the main component of red lead (kolkotar).

2 Kolkotar

Kolkotar - brown mineral paint. Other names: Parisian or English red paint, caput mortuum vitrioli, crocus, red lead; in alchemy - red lion.

The composition of kolkotar is more or less pure anhydrous iron oxide. Although anhydrous iron oxide is found in nature in very large quantities (red iron ore, iron luster), valuable varieties of this paint are produced artificially or obtained as a by-product when extracting Nordhausen acid from iron sulfate, as well as when calcining the main iron sulphide salts released from solution when preparing iron sulfate from vitriol stone.

4.3 Preparation and synthesis

Fe 2O 3is formed upon calcination in air of all hydrates and oxygen compounds of iron, as well as Fe(NO 3)3and FeSO 4. So, for example, they are calcined for 2 hours. on full flame of a Bunsen burner Fe(OH) 3, obtained by the method of G. Güttig and G. Garside.

Fe(OH) 3= Fe 2O3 + 3H 2O

As directed by D.N. Finkelshtein, 100 g Fe(NO 3)39H 2O is heated in a large porcelain crucible on an electric hotplate. At first, the salt melts quietly, forming a brown liquid that gradually evaporates. At 121° the liquid begins to boil, releasing constantly boiling 68% HNO3.

Gradually the liquid begins to thicken and frequent stirring is necessary to avoid shocks and splashing. Starting at 130°, the liquid is continuously stirred with a porcelain spatula, and it thickens, forming a paste (without stirring, the liquid suddenly hardens into a solid mass). At 132° the paste immediately crumbles into powder, continuing to release HNO3 vapor.

Without ceasing to stir, continue heating until completely dry; the whole process takes 20-25 minutes. The dry mass is ground, transferred to a crucible and calcined in a muffle at 600-700° for 8-10 hours. If the initial iron nitrate is of sufficient purity, the resulting product meets qualification x. h. Yield 95-98% theoretical, i.e. about 19 g.

To prepare a pure preparation, the calculated amount of a hot solution of oxalic acid is added to a solution of ferrous salt heated to boiling, and ferrous oxalic acid precipitates. It is filtered, thoroughly washed with water, dried and calcined in the presence of air, stirring continuously. Yield 90-93% theoretical. The resulting preparation contains 99.79-99.96% Fe2O 3.

A solution of 500 g Fe(NO 3)3 9N 2About 2 liters of water. A not too strong current NH is passed through a tube extending to the bottom of the pot. 3, washed with alkali and water. Stir the liquid from time to time using a gas outlet tube.

After precipitation is complete, the liquid is allowed to settle, the solution is decanted, and the precipitate is washed with hot water until NO is removed. 3in wash waters. Washed Fe(OH) 3dried in porcelain cups, then calcined for 5-6 hours. at 550-600°. Yield 96 g (96-97% theoretical).

Upon receiving Fe 2O 3, which serves as a raw material for the preparation of high-purity Fe, the starting iron nitrate must be extremely pure. By repeated recrystallization of Fe(NO 3)39N 2O Cleaves and Thompson obtained a preparation containing only 0.005% Si and less than 0.001% other impurities.

According to Brandt, it is most advisable to start from chemically pure iron. The latter is dissolved in HCl, the solution is treated with hydrogen sulfide when heated, filtered, and divalent iron in the filtrate is oxidized to ferric iron by boiling with a small amount of HNO 3. The mixture is evaporated twice with concentrated HCl and, having dissolved the residue in excess of dilute HCl, the solution is shaken several times with ether in a large separating funnel.

If the starting material contained Co, then the contents of the funnel are allowed to settle, the lower (aqueous) layer is drained through the tap, and a portion by volume of the mixture obtained by shaking HCl (spec. 1.104) with ether is added to the ether extract remaining in the funnel. Shake vigorously, pour off the bottom layer again and repeat the operation.

The purified ether extract is filtered, the ether is distilled off (or simply removed by heating in a water bath), and the remaining FeCl solution 3evaporate several times with HNO 3. The last evaporation is carried out with the addition of NH4NO 3.

It is advisable to carry out evaporation in a flat porcelain cup.

After evaporation, a fragile salt mass remains, easily separated from the cup. It is ground in a mortar and moderately calcined in portions of 40-50 g in a platinum cup. The residue is mixed several times with dry ammonium carbonate and again heated at low red heat, stirring frequently.

This operation is repeated until an approximately constant weight (exactly constant weight cannot be achieved, since a small amount of Fe 2O 3carried away in pairs (NH 4)2CO 3).

iron metal oxide mineral

CONCLUSION

The goals set at the beginning of the research work were fully achieved:

)Information about iron, its oxides and minerals has been collected:

Iron is a malleable, silvery-white metal with high reactivity. The compound exhibits oxidation states +2, +3, +6. Has oxides: Fe +2O, Fe 2+3O 3, Fe 3O 4 (Fe +2O·Fe +32O 3). Iron(III) oxide Fe 2O 3In addition to being obtained synthetically, it can be found in natural ore deposits. It is part of some minerals such as hematite, limonite, magnetite.

)Properties of Fe have been studied 2O 3and conclusions about its application are drawn:

Substance Fe 2O 3used to obtain pure, slightly oxidizable iron by reduction with hydrogen, as well as in electronic storage media (due to magnetism), as a polishing agent (red crocus) for steel and glass, in the food industry and is the main component of kolkotar (since the compound is coloring) .

)Several methods for synthesizing the substance have been studied. The highest product yield is 98% of the theoretical one. This result can be achieved using the method of D.N. Finkelstein, by heating Fe(NO 3)39H 2O in a large porcelain crucible on an electric hotplate with constant stirring.

BIBLIOGRAPHY

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IRON OXIDES . Oxide FeO (in technology - wustite). In crystalline the wustite lattice has vacant nodes, and its composition corresponds to the formula F x O, where x = 0.89-0.95; equation for the temperature dependence of decomposition pressure: log p(O 2, in mm Hg) = - 26730/T+ 6.43 (T > 1813 K); see also table. Practically insoluble in water, soluble in acids and alkali solutions. Easily oxidized; pyrophoric After calcination, the chemical activity and pyrophoricity of FeO decrease. In nature, the iocyte is an extremely rare mineral. It is obtained by reducing Fe 2 O 3 with hydrogen or CO or by calcination in an atmosphere of N 2 2FeC 2 O 4 * 3H 2 O. Fe 2 O 3 sesquioxide exists in three polymorphic modifications: the most stable a (hematite mineral), g (maghemite, oxymagnetite) and d (with a trigonal crystal lattice); transition temperatures a : g 677°С, g : d 777°С; D H 0 transition a : g 0.67 kJ/mol. For the a -Fe 2 O 3 modification, the equation for the temperature dependence of the decomposition pressure is: log p(O 2, in mmHg) = - 10291/T+ 5.751gT - 1.09 * 10 - 3 T -0.75 * 10 5 T - 2 - 12.33; soluble in hydrochloric and sulfuric acids, slightly soluble in HNO 3 ; paramagnetic, Néel point 953 K. Modifications g - and d -Fe 2 O 3 are ferrimagnetic; g -Fe 2 O 3 is formed during the low-temperature oxidation of Fe 3 O 4 and Fe, d -Fe 2 O 3 can be obtained by hydrolysis and oxidation of solutions of Fe(II) salts. Fe(II,III) oxide - a compound of the formula Fe 3 O 4, or FeO * Fe 2 O 3, Fe II (Fe III O 2) 2 (magnetite mineral), decomposes when heated; at 627 °C the a form transforms into b; equation for the temperature dependence of decomposition pressure: logp(O 2, in mm Hg) = = - 33265/T+ 13.37 (T > 843 K); ferrimagnet, Curie point 900 K; has a high electrical conductivity. It is soluble in acids to form Fe(II) and Fe(III) salts; natural magnetite calcined at 1200-1300 °C is practically insoluble in acids and their mixtures. When heated in air, it oxidizes to Fe 2 O 3 . It is obtained by the action of water vapor on hot iron, the reduction of Fe 2 O 3, and the oxidation of FeO. IRON OXIDES o. corresponds to a series of hydroxides. Fe(OH) 2 hydroxide is formed by the action of alkali on aqueous solutions of Fe(II) salts; quickly oxidizes to FeO(OH). Solubility in water 0.00015 g per 100 g (18°C), soluble in acids, alkali solutions with the formation of hydroxoferrates (II), for example Na 2, and NH 4 Cl solutions. Fe(III) hydroxides form a number of brown iron ores in nature: hydrohematite Fe 2 O 3 * 0.1H 2 O (solid solution of water in hematite), turyite 2Fe 2 O 3 * H 2 O (fine mechanical mixture of goethite and hydrohematite), goethite a -FeO(OH), or Fe 2 O 3 * H 2 O, lepidocrocite g -FeO(OH), hydrogoethite 3Fe 2 O 3 * 4H 2 O, limonite 2Fe 2 O 3 * 3H 2 O, xanthosiderite Fe 2 O 3 * 2H 2 O and limnite Fe 2 O 3 * 3H 2 O (solid solutions of water in goethite).

Limnite coincides in composition with art. hydrogel Fe(OH) 3, obtained by precipitation with alkali from solutions of Fe(III) salts. When calcined, Fe hydroxides transform into a-Fe 2 O 3. Hydroxide Fe(OH) 3 is a very weak base; amphoteric, when combined with alkalis or basic oxides, they form salts of ferrous acid НFeО 2 not released into the free state - ferrates (III), or ferrites, for example NaFeO 2 . When Fe(OH) 3 is oxidized in an alkaline medium with strong oxidizing agents, salts of non-existent iron acid H 2 FeO 4 are formed (FeO 3 trioxide is also unknown) - ferrates (VI), for example K 2 FeO 4, - red-violet crystals; at 120-200 °C they decompose into Fe 2 O 3, M 2 O and O 2; stronger oxidizing agents than KMnO4. Nature oxides and hydroxides of Fe - raw materials in the production of Fe, natural and synthetic - mineral pigments (see Iron mica, Iron oxide pigments, Iron lead, Mummy, Ocher, Umbra); FeO is an intermediate product in the production of Fe and ferrites, a component of ceramics and heat-resistant enamels; a -Fe 2 O 3 - component of lining ceramics, cement, thermite, absorbs. masses for gas purification, polishing material (crocus), used to produce ferrites; g -Fe 2 O 3 - working layer of magnetic tapes; Fe 3 O 4 - material for electrodes in the electrolysis of alkali metal chlorides, a component of the active mass of alkaline batteries, colored cement, lining ceramics, thermite; Fe(OH) 2 is an intermediate product in the production of IRON OXIDES o. and active mass of iron-nickel batteries; Fe(OH) 3 is a component of an absorption mass for gas purification, a catalyst in organic synthesis.

Chemical encyclopedia. Volume 2 >>

IRON OXIDES Oxide FeO (in technology - wustite). In crystalline there are vacant nodes in the wustite lattice, and its composition corresponds to the formula Fe x O, where x = 0.89-0.95; level of temperature dependence of decomposition pressure: log p(O 2, in mm Hg) = - 26730/T+ 6.43 (T > 1813 K); see also table. Practically not soluble in water, well soluble. in solutions of alkalis. Easily oxidized; pyrophoric After calcination of the chemical the activity and pyrophoricity of FeO decreases. In nature, the iocyte is an extremely rare mineral. It is obtained by reducing Fe 2 O 3 with hydrogen or CO or by calcination in an atmosphere of N 2 2FeC 2 O 4 .3H 2 O. Fe 2 O 3 sesquioxide exists in three polymorphic modifications: max. stable a (mineral hematite), g (maghemite, oxymagnetite) and d (with a trigonal crystal lattice); transition temperatures a: g 677°С, g: d 777°С; DH 0 transition a: g 0.67 kJ/mol. For the modification of a-Fe 2 O 3, the level of temperature dependence of decomposition pressure: log p(O 2, in mm Hg) = - 10291/T+ 5.751gT - 1.09.10 - 3 T -0.75.10 5 T - 2 - 12.33; sol. in hydrochloric and sulfuric acids, weakly in HNO 3; paramagnetic, Néel point 953 K. Modifications g- and d-Fe 2 O 3 are ferrimagnetic; g-Fe 2 O 3 is formed during the low-temperature oxidation of Fe 3 O 4 and Fe, d-Fe 2 O 3 m.b. obtained by hydrolysis and oxidation of solutions of Fe(II) salts. Fe(II,III) oxide - comp. f-ly Fe 3 O 4, or FeO.Fe 2 O 3, Fe II (Fe III O 2) 2 (mineral magnetite), when heated. decomposes; at 627 °C the a-form transforms into b; Level of temperature dependence of decomposition pressure: logp(O 2, in mmHg Art.) = = - 33265/T+ 13.37 (T > 843 K); ferrimagnet, Curie point 900 K; has a high electrical conductivity. Sol. in mixtures with the formation of Fe(II) and Fe(III) salts, calcined at 1200-1300 °C ambient. magnetite is practically insoluble. in compounds and their mixtures. When heated in air it oxidizes to Fe 2 O 3. It is obtained by the action of water vapor on hot iron, the reduction of Fe 2 O 3, and the oxidation of FeO. J. o. corresponds to a series of hydroxides. Fe(OH) 2 hydroxide is formed by the action of alkali on Fe(II) salts; quickly oxidizes to FeO(OH). R-value in water 0.00015 g per 100 g (18°C), sol. in alkali solutions with the formation of hydroxoferrates (II), for example. Na 2, and solution NH 4 Cl. Fe(III) hydroxides form a number of brown iron ores in nature: hydrohematite Fe 2 O 3 .0.1H 2 O (solid solution of water in hematite), turyite 2Fe 2 O 3 .H 2 O (thin mechanical mixture of goethite and hydrohematite ), goethite a-FeO(OH), or Fe 2 O 3 .H 2 O, lepidocrocite g-FeO(OH), hydrogoethite 3Fe 2 O 3 .4H 2 O, limonite 2Fe 2 O 3 .3H 2 O, xanthosiderite Fe 2 O 3 .2H 2 O and limnite Fe 2 O 3 .3H 2 O (solid solutions of water in goethite).

Limnite coincides in composition with art. hydrogel Fe(OH) 3, obtained by precipitation with alkali from solutions of Fe(III) salts. When calcined, Fe hydroxides transform into a-Fe 2 O 3 . Hydroxide Fe(OH) 3 is a very weak base; amphoteric, when combined with alkalis or basic oxides, they form salts not isolated in free. state of ferrous compounds HFeO 2 - ferrates (III), or ferrites, eg NaFeO2. When Fe(OH) 3 is oxidized in an alkaline environment with strong oxidizing agents, salts of the non-existent iron acid H 2 FeO 4 are formed (FeO 3 trioxide is also unknown) - ferrates (VI), for example. K 2 FeO 4 - red-violet crystals; at 120-200 °C they decompose into Fe 2 O 3, M 2 O and O 2; stronger oxidizing agents than KMnO4. Nature Fe oxides and hydroxides - raw materials in Fe production, natural and synthetic - mineral. pigments (see Iron mica, Iron oxide pigments, Red lead, Mummy, Ocher, Umber); FeO - interm. product in the production of Fe and ferrites, component of ceramics and heat-resistant enamels; a-Fe 2 O 3 - a component of lining ceramics, cement, thermite, will absorb. masses for gas purification, polishing material (crocus), used to produce ferrites; g-Fe 2 O 3 - magnetic working layer. ribbons; Fe 3 O 4 - material for electrodes in the electrolysis of alkali metal chlorides, a component of the active mass of alkaline batteries, colored cement, lining ceramics, thermite; Fe(OH) 2 -intermediate. product upon receipt of liquid o. and active mass of iron-nickel batteries; Fe(OH) 3 - component of absorption mass for gas purification, catalyst in org. synthesis. Lit.: see under art. Iron. E. F. Wegman. Chemical encyclopedia. - M.: Soviet Encyclopedia Ed. I. L. Knunyants 1988

• In construction it is used for painting concrete, cement, brick and ceramics. It is one of the main dyes for paving slabs and sand-lime bricks. To obtain a rich color, dyes are added in an amount of 2-5% by weight of the mixture.
• In the paint and varnish industry, iron oxide pigments are used for paints, enamels and primers; they are perfectly compatible with almost all types of film-forming substances.
• Due to their unique properties, these dyes are also actively used in other industries, for example, for coloring linoleum, plastics and in printing inks.
• As a catalyst in the production of ammonia.
• For thermite welding of steel structures.
• As a carrier of information in magnetic media.
• As a polish for steel and glass.
• As food coloring E172.

Description

Physicochemical characteristics

An amphoteric oxide with a high predominance of basic properties. Red-brown color. Thermally stable up to high temperatures. Formed when iron burns in air. Does not react with water. Reacts slowly with acids and alkalis.

Packing

Big bag 1100 kg.

Storage

Packaging and storage: 25 kg bags with a polyethylene liner.

Red pigment LPM produced by Kimpe, France

Bulk density: 350-550 kg/m3 Humidity after calcination for 1 hour at 105°C: 0.18%-0.5% Specific surface area: 3.5-5 m2/g Density: 0.55-0.80 kg /m3