Method of production of the ferric oxides

FIELD: chemical industry; metallurgy industry; other industries; methods of production of the high purity ferric oxides.

SUBSTANCE: the invention is pertaining to the method of production of the high purity ferric oxides and may be used in production of the pigments and the catalysts at production of the high purity ferric oxides. The ferric oxides are produced by interaction of the metallic iron made in the form of the microball-shaped particles either the scrap, or the turning chips, which dimensions are such, that the area of their surface per one kg of iron and per one liter of the reaction medium makes more than 0.01 m2 with the being stirred water solution of the carboxylic acid having рКа from 0.5 up to 6 for the first carboxyl and capable to thermolysis in the open air at the temperature of from 200 up to 350°С into carbon dioxide and the water. The ratio between the moles of the carboxylic acid and g-atoms of the iron makes from 0.03 up to 1.5 and the mass ratio of the water/iron - from 1 up to 20, the microball-shaped particles are kept in the suspension by stirring. The produced carboxylate of the ferrum (II) is oxidized up to carboxylate of the ferrum (III) with the oxidant selected from oxygen, the oxygen-containing gaseous mixture and hydrogen dioxide. The earlier produced carboxylate of the ferrum (II) also may be exposed to the oxidizing. Then the carboxylate of the ferrum (III) is heated up in the open air till production of the oxides. The invention allows to increase the purity of the ferric oxides and productivity at their production.

EFFECT: the invention ensures the increased purity of the produced ferric oxides and productivity at their production.

9 cl, 12 ex

 

The present invention relates to an improved process for the preparation of iron oxide of high purity, are applicable, in particular as pigments and precursors of catalysts or materials for electronic devices.

The method most commonly employed to produce iron oxides used as pigments, as a starting material can be applied to etching liquid containing sulfate or iron chloride (II), obtained in the steel industry or in the process of obtaining titanium dioxide.

The acidic aqueous solution of salts of iron (II) is first neutralized by dissolving iron scrap, and then treated under oxidizing conditions with sodium hydroxide, with the aim of precipitation of FeOOH nuclei, which is then pumped by the pump into the reactor containing iron scrap and blown by the air stream.

The resulting sulfate (chloride) iron (III) is hydrolyzed, forming FeOOH or Fe2O3; released sulfuric or hydrochloric acid reacts with iron, forming sulfate or iron chloride (II), which is then oxidised to iron (III)salts. The time of interaction varies from several days to several weeks depending on the conditions of interaction and type the desired pigment.

The advantage of this method compared to other methods is the limited application of alkali and sulfate is or iron chloride (II). A small amount of salt of iron (II)necessary in the beginning, continuously supplemented during the process by dissolving iron sulfuric or hydrochloric acid released during the interaction.

The disadvantage of this method is the problem of elimination, even after a thorough washing, impurities anions sulfate and chloride present in the oxides, which negatively affects the quality of the pigments.

For example, to reduce the contents of these anions to values that are acceptable in obtaining high-quality red pigments, it is necessary to process phase precipitate oxides concentrated solutions of NaOH (USP 5614012).

GB 1226876 describes a method of obtaining high-purity FeOOH, the right to obtain ferrites used in electronic devices, in which electrolytic iron, the average particle size of which ranges from 20 to 140 μm, is subjected to the interaction in terms of oxidation air, noise at high speed to obtain a uniform aqueous suspension of particles of iron, with an acid selected from sulfuric, hydrochloric, nitric and acetic acid used in molar concentration, which constitutes less than 0.01, and in a molar ratio of iron constituting more than 0.02, preferably from 0.26 to 0.55. Iron is used in a quantity not exceeding 25 g/l, with a mass soothes the tion between the solution and the iron is at least 40.

Temperature interaction ranges from 50 to 70°With: if the temperature is above 70°With undesired oxides such as spinel, which are also formed at temperatures below 70°if the iron concentration above 25 g/l

At temperatures below 50°With the resulting oxide particles too small to filter and wash, making it difficult to achieve a content of impurities formed by the acid radicals which is less than 0.1 wt.%.

The desired particle size FeOOH following: a length of several microns, and the width and the thickness is more than 0.3 and 0.1 micron, respectively.

If the acid concentration is too high (greater than 0.25 mol when using sulfuric acid), the output FeOOH is reduced even more significantly due to dissolution of iron ions in the mother solution. The performance of this method is 20-26 g FeOOH per liter of slurry per hour.

The aim of the present invention is to develop a method of producing iron oxides capable of resolve difficulties known methods.

It was unexpectedly discovered the possibility to partially overcome or mitigate the disadvantages of the known methods and receipt of iron oxides with high performance, certainly higher than productivity known to date methods, and with essentially full the nd conversion of iron oxides, which is almost free from alkali, alkaline earth and ammonium ions, and in which after washing remains relatively small amount of impurity anions of carboxylic acids, which, however, can be removed at the stage of conversion of oxides to oxides of Fe2O3.

The method in accordance with this invention includes the following stages:

a) interactions in the mixed aqueous solution of aliphatic and/or aromatic carboxylic acids containing one or more carboxylic groups with a pKa of from 0.5 to 6 at ambient temperature relative to the first carboxyl able to decompose when heated in air at a temperature of from 200 to 350°with formation of carbon dioxide and water, and to form the salt of iron (II), soluble in aqueous solution under conditions of interaction with microsurvey iron having an average particle diameter of not more than 250 μm, preferably from 30 to 200 microns, or, always under stirring with iron lathe scrap or scraps of having such dimensions that their surface is greater than 0.01 m2per kg of iron and per liter of solution, the ratio between the moles of acid and g-atoms of iron is from 0.03 to 1.5, the mass ratio of water to iron is from 1 to 20 at the operating temperature from 0 to 100°C;

b) oxidation to carboxylate the iron (III) carboxylate iron (II), obtained in stage a), the oxidant used in excess relative to the stoichiometric amount of salt of iron (II)oxidized in salt of iron (III) selected from oxygen, oxygen-containing gaseous mixture, such as air, hydrogen peroxide, ozone, organic peroxides and hydroperoxides.

Alternatively, the oxidation can also be subjected to prior carboxylates iron (II), derived from the acids listed in PA), or their mixtures with one or more of the foregoing acids, while the molar ratio between the anion contained in the salt and acid (in the case of mixtures with acids), and g-atoms of iron is from 0.03 to 1.5. All other alternative conditions relevant to the form of iron, the mass ratio of water/iron, temperature interaction, the oxidizing agent and mixing environment are the same as those in PA) and (b).

The temperature in stages a) and b) is preferably from 5 to 70°C, the ratio between the moles of acid and g·Fe atoms is from 0.05 to 0.8, and the mass ratio of water/iron ranges from 2 to 10.

Oxygen and air for oxidation of ions of iron (II) ion iron (III) is used in large excess relative to the stoichiometric amount; excess hydrogen peroxide, ozone and peroxides is 2-4 RA is a and more.

At the stage of (a) the interaction is preferably carried out in a stream of inert gas, such as nitrogen, to avoid the formation of explosive mixtures of oxygen with hydrogen generated in the process of dissolution of iron.

Stages a) and b) can also be carried out simultaneously, in particular, when used as oxidizers hydrogen peroxide, peroxides or hydroperoxides.

When using air or oxygen interaction is carried out in a strong stream of gas in order to remove by-produced hydrogen, thus avoiding the formation of explosive mixtures.

Stage oxidation of salts of iron (II) salt of iron (III) can be carried out in the presence of FeOOH nuclei obtained separately in accordance with known methods.

The presence of embryos allows you to reduce the size of the particles. For example, the use of seed from goethite in the amount of 4 to 10 wt.%, in the atmosphere of oxygen at 30°C, ratio of HCOOH/Fe, amounting to 0.5, and complete conversion of iron leads to a sharp decrease in particle size.

The iron is preferably used in microservices form, the average particle diameter is preferably from 40 to 150 microns; the carbon content is preferably less than 0.15 wt.%; the number of such elements as manganese, Nickel, copper and silicon, when is Alicia, preferably less than 1 wt.%.

The amount of manganese and Nickel is preferably less than 0.05 wt.%, and the amount of copper is preferably less than 0.2 wt.%.

Applicable typical microturbine iron is produced by steel re-processing in accordance with known methods scrap resulting from processing of metal sheets.

Iron having the above characteristics purity, especially applicable for the production of high-purity iron oxide for pigment having an important color characteristics, and/or precursors for the preparation of catalysts.

Depending on the purpose of the oxides can also be used alloy steels containing alloying element in an amount of about 10 wt.%.

Chromium, manganese, Nickel, tungsten and silicon are typical alloying elements.

Upon receipt of the oxides of iron, designed to obtain ferrites for electronic devices, use of electrolytic iron.

When using iron lathe shavings complete conversion requires more time. Can be used scrap or pieces of iron which are larger than the lathe shavings, provided that the area per kg of iron per liter and the reaction medium is higher than 0.01 m2.

Examples of PR is applicable carboxylic acids are formic, acetic, glycolic, oxalic acid, trichloro-, dichloro - and Chloroacetic acid, bromoxynil, Eudoxus, Pirovano grapes of acid, malonic acid and propionic acid.

Preferred are formic and acetic acid.

In the same conditions with the use of hydrogen peroxide as a result of the application of acetic acid get goethite, glycolic acid is a mixture of maghemite (maghemite and hematite, while the use of formic acid results in only maghemite. As a result of application of acetic acid with oxygen at 30°To get a high yield of oxide with a large specific surface area, which may exceed 260 m2/g; phase are essentially phase resulting from the application of formic acid, but with a slightly different distribution.

The purity of the iron oxides, which can be obtained by the method in accordance with this invention, particularly high (provided that the starting material is pure iron), as FeOOH precipitate formed in the form of goethite and/or lepidocrocite (lepidocrocite) or in the form of Fe2O3(maghemite), after washing with water contains relatively small (less than 0.5%) amount of impurities formed from anions of carboxylic acids, expressed in the form of carbon.

These impurities can be completely what Delany during the stage of heating the oxides in the air to a temperature component from 200 to 350°C. by Heating to 400°With goethite into hematite; 450°With lepidocrocite becomes maghemite, which becomes hematite at temperatures above 450°C.

When receiving use distilled water, cations such as alkali and/or alkaline earth cations, and anions sulfate or chloride are also missing.

The performance of this method is undoubtedly higher performance known methods: for example, using oxygen as oxidant and time of oxidation in 20 hours can be obtained 290 grams or more of Fe2About3per kg of the reaction mixture.

When using hydrogen peroxide optimum temperature is 50-60°With; the preferred ratio of hydrogen peroxide and iron is 1.4-1.8 moles of hydrogen peroxide on g-atom of iron; oxidation time exceeds 8 hours, and the preferred ratio of moles of carboxylic acid and g·iron atoms is 0.6 or less; with a ratio of approximately 1, the concentration of iron dissolved in the mother solution can be very high, but it decreases almost to zero when the ratio of the average of 0.6 or less.

The use of hydrogen peroxide and complete conversion of iron allow to obtain, depending on the operating conditions, as pure goethite, and Chi is th maghemite, or their mixture.

For example, if the ratio of the average of 1.6 moles of H2About2to g·the iron atom, and the ratio of the average of 1.12 moles of formic acid to g·the iron atom, at 60°With full conversion of iron can be obtained pure goethite; the same result is obtained using acetic acid in the ratio amounting to 0.5 moles on g-atom of iron.

Net maghemite obtained when the ratio of the average of 1,624 mol H2About2to g·the iron atom, and the ratio of the average of 0.4-0.6 mol of formic acid to g·the iron atom, with 50-70°and complete conversion of iron.

Using oxygen, it is possible to obtain a mixture of goethite and lepidocrocite. When using air reactivity is lower than oxygen; the specific area of the oxide is less and the content of soluble iron is usually higher; at 50-70°it falls to values typically below 1 wt.% from the masses of the used iron.

The specific surface area (BET) phase largely depends on the operating conditions: if the system is set and the method does not allow for the use of embryos, the specified surface area depends only on the temperature.

Maghemite has the appearance of a globular particle size of about 1 micron; specific surface area is 4-12 m2/year

Particles together in aggregates, the usual having a size less than 10 microns.

Upon receipt of goethite using hydrogen peroxide elementary particles concourse in granules (globules), which, in turn, partially aggregated.

Applying oxygen, get rounded particles, which have a very fine structure and size less than microns, or agglomerated, forming aggregates larger than 10 microns.

Lepidocrocite and mixtures of goethite-lepidocrocite have the form of globular particles with a structure resembling "desert rose".

Various phase control using x-ray phase analysis (XRD).

The following examples are given with the purpose of non-limiting illustration of the present invention.

EXAMPLES

The device used in the various examples, includes a glass reactor with a volume of 1-3 liters, equipped with a cover, with the cover having various inlet, and stirrer with variable speed; for tests with gaseous oxidizer reactor can be equipped with a gas mixer and divider stream.

Counterflow cooling device installed at the outlet of the reaction gas; feeding hydrogen peroxide using the metering pump; provide for a system for regulating the speed of flow and its measurement in gas supply; moreover, for temperature regulation test by circulating the fluid in the reactor vessel using thermostat cryostat), as for measuring (monitoring) operating temperature using thermometer.

EXAMPLE 1

200 cm3deionized water and 37 g of formic acid are placed in a 1-liter reactor, the temperature of which was adjusted to 60°with a heating casing; carry out the mixing in the reactor, add 40 g microservices iron. Iron check so that it formed the desired suspension, and then apply Micronase for introduction into the reactor 100 cm335% hydrogen peroxide.

Adding lasts for approximately 4.2 hours and throughout the test the temperature of the support at the level of 60°C.

In the end the resulting mass is poured into a vessel from which unreacted iron is removed using a magnet. Then the reaction product is separated by filtration and placed in an oven at 140°With at night. The mother liquor is subjected to analysis to determine the iron content. Obtained essentially pure goethite: conversion of iron is 90%, while the portion of the metal dissolved in the mother solution. Specific surface area is 111 m2/year

EXAMPLE 2

200 cm3deionized water and 33 g of formic acid are placed in a 1-liter reactor, the temperature of which was adjusted to 60°with a heating casing; carry out stirring, and the reactor add 40 g mi is reserving iron. Iron check so that it formed the desired suspension, and then apply Micronase for introduction into the reactor 100 cm335% hydrogen peroxide as follows: feed pump operate with a speed of 13 cm3/hours 4.1 hours, and then with a speed of 3 cm3/hourly for 16 hours. In General, the addition of hydrogen peroxide continue for a period of 20.5 hours, and the temperature is maintained at 60°C.

The resulting product is filtered, and the residue is dried in the same manner as in example 1.

The mother liquor is subjected to analysis to determine the iron content. The mixture of goethite and maghemite; conversion of iron is 100%; the amount of iron in the mother solution is 5.8% of the administered iron.

EXAMPLE 3

200 cm3deionized water and 16.5 g of formic acid are placed in a 1-liter reactor, the temperature of which was adjusted to 50°with a heating casing; carry out the mixing in the reactor, add 40 g microservices iron. Iron check so that it formed the desired suspension, and then apply Micronase for introduction into the reactor 100 cm335% hydrogen peroxide.

The addition is carried out for approximately 16,7 hours, during the test in the reactor serves a small stream of nitrogen, and the temperature is maintained at 50° C.

At the end of the whole mass is filtered and the resulting solid fraction are placed in an oven at 140°for the night.

The mother liquor is subjected to analysis to determine the iron content. The amount of iron in the mother solution, negligible; specific surface area is 7.6 m2/year

EXAMPLE 4

300 cm3deionized water and 16.5 g of formic acid are placed in a 1-liter reactor, the temperature of which was adjusted to 20°with a heating casing and which serves a small flow of nitrogen; carry out stirring, and the reactor add 40 g microservices iron. Iron check so that it formed the desired suspension, and then the system is kept in a nitrogen atmosphere for 4 hours.

At the end of the nitrogen is replaced by oxygen and the system was kept at 20°C for another 20 hours.

The resulting product is filtered and the solid fraction is dried at 140°With during the night.

The mother liquor is subjected to analysis to determine the iron content. The mixture of goethite and lepidocrocite, and the conversion of iron is 100%and the amount of iron in the mother solution is 2.4%. Specific surface area of 140 m2/g, and after heating up to 400° - 48,1 m2/year

EXAMPLE 5

300 cm3deionized water and 16.5 g of formic acid are placed in a 1-whether the normal reactor, the temperature at which lead up to 70°with a heating casing and which serves a small flow of nitrogen; carry out stirring, and the reactor add 40 g microservices iron. Iron check so that it formed the desired suspension, and then the system is kept in a nitrogen atmosphere for 4 hours.

At the end of the nitrogen is replaced by oxygen and the system was kept at 70°C for another 20 hours.

The resulting product is filtered and the solid fraction is dried at 140°With during the night.

The mother liquor is subjected to analysis to determine the iron content. The mixture of goethite and lepidocrocite, and the conversion of iron is 100%and the amount of iron in the mother solution is 0.38%. Specific surface area is 9.5 m2/g, and after heating up to 400°20.5 m2/year

EXAMPLE 6

300 cm3deionized water and 6.6 g of formic acid are placed in a 1-liter reactor, the temperature of which was adjusted to 70°with a heating casing and which serves a small flow of nitrogen; carry out the mixing in the reactor, add 40 g microservices iron. Iron check so that it formed the desired suspension, and then the system is kept in a nitrogen atmosphere for 4 hours.

At the end of the nitrogen is replaced by oxygen and the system was kept at 70&x000B0; C for another 3 hours.

The mother liquor is subjected to analysis to determine the iron content. The mixture of goethite and lepidocrocite, and the conversion of iron is essentially complete.

EXAMPLE 7

300 cm3deionized water and 16.5 g of formic acid are placed in a 1-liter reactor, the temperature of which was adjusted to 30°using a heating casing and which serves a small flow of nitrogen; carry out stirring, and the reactor add 40 g microservices iron. Iron check so that it formed the desired suspension, and then the system is kept in a nitrogen atmosphere for 4 hours.

At the end of the nitrogen is replaced by air and the system is maintained at 30°C for another 20 hours.

The residual iron is removed with a magnet, the resulting product is filtered and the solid fraction is dried at 140°With during the night. The mother liquor is subjected to analysis to determine the iron content. The mixture of goethite and lepidocrocite with a small amount of hematite.

Conversion of iron is of 85.5%, and the amount of iron in the mother solution is 15% of the injected iron.

EXAMPLE 8

300 cm3deionized water and 13.2 g of formic acid are placed in a 1-liter reactor, the temperature of which was adjusted to 30°with a heating casing and which serves not the large flow of nitrogen; carry out stirring, and the reactor type 80 g microservices iron. Iron check so that it formed the desired suspension, and then the system is kept in a nitrogen atmosphere for 4 hours.

At the end of the nitrogen is replaced by oxygen and the system was kept at 70°C for 20 hours; the entire mixture is filtered, and the solid fraction is dried at 140°With during the night. The mother liquor is subjected to analysis to determine the iron content. The mixture of goethite and lepidocrocite, and the conversion of iron is essentially complete, and 15% of the injected iron present in the mother solution.

EXAMPLE 9

1500 cm3deionized water and 15 g of formic acid are placed in a 3-liter reactor, the temperature of which was adjusted to 30°with a heating casing and which serves a small flow of nitrogen; carry out stirring, and the reactor type 300 g microservices iron. Iron check so that it formed the desired suspension, and then the system is kept in a nitrogen atmosphere for 4 hours.

At the end of the nitrogen is replaced by oxygen and the system was kept at 30°C for another 20 hours.

The residual iron is removed with a magnet, the resulting fraction is filtered, and the solid fraction is dried at 140°With during the night. The mother liquor is subjected to analysis to determine what the contents of iron. Net lepidocrocite, specific surface area which is 6.8 m2/g, and after heating up to 400° 18 m2/year Conversion of iron is to 95.7%, and the amount of iron in the mother solution is 0.11% of the administered iron.

EXAMPLE 10

1500 cm3deionized water and formic acid are placed in a 3-liter reactor, the temperature of which was adjusted to 40°with a heating casing and which serves a small flow of nitrogen; carry out the mixing in the reactor, add 200 g microservices iron at a ratio of average of 0.5 moles of formic acid per g-atom of iron. Iron check so that it formed the desired suspension, and then the system is kept in a nitrogen atmosphere for 4 hours.

At the end of the nitrogen is replaced by oxygen and the system was kept at 40°C for 19 hours.

The product is filtered and the solid fraction is dried at 140°With during the night. The mother liquor is subjected to analysis to determine the iron content. The mixture of goethite and lepidocrocite, specific surface area which is 44 m2/g, and after heating up to 400°C - 28 m2/year Conversion of iron is 100%and the amount of iron in the mother solution is 2.9% of the amount introduced of iron.

EXAMPLE 11

1500 cm3deionized the odes and formic acid are placed in a 3-liter reactor, the temperature at which lead up to 10°using cooling casing and which serves a small flow of nitrogen; carry out stirring, and the reactor type 300 g microservices iron at a ratio amounting to 0.22 moles of formic acid per g-atom of iron. Iron check so that it formed the desired suspension, and then the system is kept in a nitrogen atmosphere for 4 hours.

At the end of the nitrogen is replaced by oxygen and the system was kept at 10°C for 19 hours.

The product is filtered and the solid fraction is dried at 140°With during the night. The mother liquor is subjected to analysis to determine the iron content. Obtained pure goethite, specific surface area which is 91 m2/g, and after heating up to 400°s - 37 m2/year Conversion of iron is essentially complete, and the amount of iron in the mother solution is negligible.

EXAMPLE 12

1500 cm3deionized water and formic acid are placed in a 3-liter reactor, the temperature of which was adjusted to 5°using cooling casing and which serves a small flow of nitrogen; carry out the mixing in the reactor, add 200 g microservices iron at a ratio of average of 0.27 moles of formic acid per g-atom of iron. Iron check so that it formed a necessary suspense is, and then the system is kept in a nitrogen atmosphere for 4 hours.

At the end of the nitrogen is replaced by oxygen and the system is maintained at 5°C for 19 hours.

The residual iron is removed with a magnet, the resulting product is filtered and the solid fraction is dried at 140°With during the night. The mother liquor is subjected to analysis to determine the iron content. Conversion of iron is of 97.8%, and the amount of iron in the mother solution of 1.5%. The specific area of the particles is 144 m2/g, and after heating up to 400° - 47,6 m2/year

1. The method of producing iron oxide of high purity, containing the following steps performed sequentially or simultaneously:

a) interaction of metallic iron in the form of microsurvey particles with an average diameter of not more than 250 μm or in the form of scrap or scraps, the dimensions of which are such that their surface area per kg of iron per liter and the reaction medium is higher than 0.01 m2with a mixed aqueous solution of carboxylic acid containing one or more carboxylic groups with a pKa of from 0.5 to 6 when the ambient temperature on the first carboxyl able to decompose when heated in air at temperatures from 200 to 350°With the carbon dioxide and water, and also to form a salt of iron (II), soluble in this aqueous solution under conditions of interaction the interaction, the ratio between the moles of carboxylic acid and g-atoms of iron is from 0.03 to 1.5, the mass ratio of water to iron is from 1 to 20, the temperature of the interaction is from 0 to 100°and microturbine particles are kept in suspension by stirring;

b) oxidation to carboxylate iron (III) carboxylate iron (II)obtained in stage a), oxidant selected from oxygen, oxygen-containing gaseous mixture and hydrogen peroxide and is used in excess relative to the stoichiometric amount in the oxidation of iron salts (II) to iron salts (III);

C) formation of oxides of iron carboxylates iron (III), obtained in stage b), when heated in air.

2. The method according to claim 1, in which the temperature of the interaction is from 5 to 70°and the molar ratio between the carboxylic acid and g-atoms of iron is from 0.05 to 0.8.

3. The method according to claim 1 or 2, in which the oxidant used oxygen or hydrogen peroxide.

4. The method according to any one of claims 1, 2 and 3, in which particles microservices iron have an average diameter of less than 200 microns.

5. The method according to any one of claims 1 to 4, in which the content of carbon in iron is less than 0.15 wt.%, and the content of alloying elements is less than 0.3 wt.%

6. The method of producing iron oxide of high purity, containing the first oxidation oxidant, selected from oxygen, oxygen-containing gaseous mixture and hydrogen peroxide and is used in excess relative to the stoichiometric amount in the oxidation of iron from the iron ion (II) to ion iron (III), obtained in advance of the carboxylate iron (II) carboxylic acids with pKa in the first carboxyla from 0.5 to 6, is able to decompose when heated from 200 to 350°on CO2and H2Oh, or mixtures of the specified carboxylate with the above carboxylic acid, and an aqueous solution of the carboxylate is subjected to interaction with iron in the form of microsurvey particles with an average diameter of less than 250 microns, or iron lathe turnings or scrap material of such size that the area of the surface per kg of iron per liter and the solution is more than 0.01 m2and the molar ratio of the anion present in the salt and acid, and g-atoms of iron is from 0.03 to 1.5, the mass ratio of water to iron is from 1 to 20, the temperature of the interaction is from 0 to 100°and microturbine iron is kept in the suspended state by stirring, and then heating the obtained carboxylates in the air.

7. The iron oxides obtained by the method according to any of claim 1 or 6, and oxides FeOOH have a specific surface area of from 1 to 300 m2/g; maghemite Fe2About3weight is a horse of a surface 1-15 m 2/g, while these oxides free from alkaline and/or alkaline-earth ions and/or ammonium ions, and anions sulfate and/or chloride.

8. Pigments derived from iron oxides according to claim 7.

9. Catalysts containing iron oxides according to claim 7 or derived from oxides according to claim 7.



 

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The invention relates to the technology of production of iron oxide pigments used as colorants

FIELD: pigment technologies.

SUBSTANCE: invention is intended for use in varnish-and-paint industry and in rubber and plastics production. Red iron oxide pigment preparation comprises: oxidation of aqueous solutions of ferric sulfate or suspensions of ferric hydroxide with air oxygen at quasi stationary temperature and pH values of reaction medium; hydrothermal heat treatment of suspension of ferric oxyhydroxides in periodical or continuous regimes in autoclaves; washing-out of pigment from water-soluble salts; drying and grinding of the pigment. During hydrothermal heat treatment FeOOH suspension is affected by nanosecond electromagnetic pulses having following characteristics: pulse duration 0.5-5 ns, pulse amplitude 4-10 kv, pulse repetition frequency 200-1000 Hz. Process is carried out at 130-200°С.

EFFECT: lowered FeOOH suspension hydrothermal heat treatment temperature and increased pigment preparation productivity.

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FIELD: metallurgy; building industry; varnish and paint industry.

SUBSTANCE: the invention is pertaining to the field of metallurgy, building industry, varnish and paint industry, in particular, to the method of production of a red ferrioxide pigment. A ball mill is charged with industrial water, loaded with iron oxide with concentration of 500-900 g/dm3, poured with a neutralizing agent in the amount ensuring pH 6 ÷ 10. The iron oxide is formed at a thermal decomposition of the hydrochloride solutions used at etching treatment of carbon steels. As a neutralizing agent it is possible to use caustic soda, a slaked lime, microcalcite. The suspension is pulped for 3-5 hours, put in a reactor with a stirrer, where it is washed out with formation of a suspension, filtered off and dried. The target product has the following parameters: pH 5 ÷ 8; the share of water-soluble salts - 0.02-0.03 %; dispersing ability - 27-30 microns; hiding power - 6 ÷7 g/m2. The invention allows to simplify process and to upgrade parameters of the pigment.

EFFECT: the invention allows to simplify process and to upgrade parameters of the pigment.

2 cl, 1 tbl, 1 ex

The invention relates to the processing of oxygen-containing compounds of iron for experimental and industrial production of hydrogen, oxygen, or both separately

The invention relates to the field of paints and varnishes based on synthetic binders, used in obtaining protective coatings

The invention relates to technology of inorganic substances and can be used to obtain iron coagulants-flocculants for water treatment, deposition of mineral solids from aqueous suspensions and concentration of dissolved metals in them

The invention relates to metallurgy, in particular to methods of producing iron oxide (III) for ferrites with low content of impurities from spent hydrochloric acid pickling solutions rolling production

The invention relates to the production of metal oxides and, in particular, iron oxide (III), used as the primary source component in the manufacture of ferrites

The invention relates to inorganic chemistry, and in particular to methods for producing metal oxide, and can be used to obtain pigments, catalysts, semiconductor materials

FIELD: chemical industry; mechanical engineering; etching and galvanic production branches; methods of production of the magnetic liquids.

SUBSTANCE: the invention is pertaining to the field of production of the magnetic liquids from the wastes of the etching and galvanic productions. The invention problem is production of the magnetic liquids on the basis of the water using the waste etching solution of the engineering plants as the source of the bivalent iron and the sediment-waste after purification of the waste waters of the galvanic manufacture by electrocoagulation - as the source for production of the trivalent iron. The problem is settled due to the fact, that the method provides for co-sedimentation of the salts of the bivalent and trivalent iron by the surplus of the ammonia concentrated solution, coating of the surface of the particles with the adsorbed layer of the stabilizing substance - sodium oleate, heating of the suspension and bringing it up to boiling at the constant hashing, centrifuging of the mixture after its cooling for separation of the large- dispersed particles be notable for the fact, that as salts of the bivalent and trivalent iron using the mixture of the waste etching solution of the engineering plants containing FeSO4 and the muriatic sediment-waste containing Fe(OH)3 in the ratio of 2:3 after purification of the sewage of the galvanic production by electrocoagulation.

EFFECT: the invention ensures production of the magnetic liquids on the basis of the water using the waste etching solution of the engineering plants as the source of the bivalent iron and the sediment-waste after purification of the waste waters of the galvanic manufacture by electrocoagulation - as the source for production of the trivalent iron.

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