The method of producing iron oxide (iii) for ferrites


(57) Abstract:

The method of producing iron oxide (III) to iron from spent etching solutions, which consists in adding to the solution polydimethyldiallylammonium in the amount of 1 - 2 wt.% in terms of SiO2contained in the solution, filtering the resulting precipitate, and the solution supply to oxidative thermal decomposition.

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 of the rolling mills.

Used for the production of ferrites iron oxide (III) should be inexpensive and have a low content of impurities such as silicon, magnesium, copper, Nickel, chromium and others.

A method of obtaining inexpensive iron oxide (III) from hydrochloric acid waste pickling solutions (FTS) rolling production by feeding the solution into the furnace, thermal decomposition when blowing furnace gas with oxygen, where thermal decomposition of the chlorides of iron, forming iron oxide (III) [1].

However, the thus obtained iron oxide (III) has increased steriade runoff from use as a flocculant of polydimethyldiallylammonium [2] . However, in this case used flocculant type. In addition, in the work not specified on the cleaning solutions of the above-mentioned non-ferrous and ferrous metals.

The closest technical solution is the method of producing iron oxide (III) with a small content of impurities (silicon) [3], which consists in the fact that the OTP type high-molecular flocculant, which is used as polyacrylamide in the amount of 4% relative to the weight of silicon compounds contained in the solution (in terms of SiO2). The solution was incubated for 20 min for coagulation. Dioxide is filtered off and the solution serves on thermal decomposition where to get iron oxide (III). The disadvantage of this method is that according to this method ensures only clean from compounds of silicon and does not provide magnesium, copper, Nickel, chromium and other impurities.

The aim of the invention is to increase the purity of the obtained iron oxide (III).

This objective is achieved in that in the method of producing iron oxide (III) from hydrochloric OTP rolling operations, including the addition of high-molecular flocculant, exposure and filtration of the solution followed by immediatamente in the amount of 1 - 2 wt.% in terms of SiO2contained in the solution. Due to the introduction of the compounds into solution in the specified quantity in the etching solution is formed by a silica gel, which is equivalent to arise in the solution of the adsorbent, which enables effective cleaning from the following impurities: magnesium, copper, chromium, Nickel and others. In the next step, the silica gel is separated from the solution by filtration through Samaraenergo column with Mylar download. The purified solution serves to oxidative thermal decomposition where to get pure iron oxide (III). Better cleaning solution from silicon compared using as the collector of impurities polydimethyldiallylammonium according to the proposed method due to the fact that polydimethyldiallylammonium translates nesfokusirovanno silicon compounds volatile chetyrehhloristy silicon, which is removed when termorasshirennyi.

Polydimethyldiallylammonium get the reaction taking place at room temperature between dimethylamine and allyl fluoride, followed by polymerization of the monomer at 75-110oC in the presence of peroxodisulfate ammonium.

diallylammonium in the amount of 1 - 2 wt.% in terms of SiO2contained in the solution. It is this concentration specified flocculant leads to the production of iron oxide (III) with low content of impurities (silicon, Nickel, chromium, magnesium, copper, and others). These differences allow to draw a conclusion on the conformity of the proposed technical solution the criterion of "novelty". The features distinguishing the claimed technical solution to the prototype, not identified in other technical solutions and, therefore, provide the inventive solution according to the criterion of "significant differences".

The inventive method can be implemented as follows:

Example. To 5 liters of waste hydrochloric acid pickling solution containing the chlorides of iron (250-300 g/l), the silicon compound (0.5 g/l) and other impurities (Nickel, chromium, magnesium, copper), added polydimethyldiallylammonium, left the solution in contact with the polyelectrolyte for 20 min, then the solution was filtered on a column with Mylar loading and subjected to thermohydraulic, during which he received the iron oxide (III). In parallel experiments received iron oxide (III) according to the method and analog prototype. Tests for impurities was performed according to standard techniques. The results are shown in the generate OTP (see Settings oxides and carbonates of manganese for iron". The Handbook, edited by Golubkov L. A. , 1987).

When the outlet concentration outside of the claimed invention (see table) at the bottom there is a noticeable decrease in the degree of purification of Fe2O3the upper output of the scope of the invention or does not increase the degree of purification or even reduces it.

The analysis of the data shown in the table, it is seen that the inventive method is much more efficient compared to the prototype. Indeed, the degree of purification of silicon, copper, Nickel, chromium and magnesium when using the proposed solutions increases by about 1.5 times.

The method of producing iron oxide (III) to iron from spent pickling solution of rolling operations, including cleaning, initial solution by the introduction of the flocculant, separating the resulting precipitate and oxidative heat treatment of the filtrate, characterized in that as a flocculant injected polydimethyldiallylammonium in the amount of 1 - 2 wt.% in terms of SiO2containing in solution.


Same patents:

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: 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

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.

1 tbl, 12 ex

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

FIELD: chemistry.

SUBSTANCE: this invention refers to production and application of sorbents. Offered is preparation method of composition for phosphate adsorption, including the stages as follows: a) base addition to aqueous solution containing ferric (III) sulphate and/or nitrate salt solution to deposit ferric hydroxide, b) optional water flush of produced deposit to produce aqueous suspension of ferric hydroxide, c) addition to produced aqueous suspension of component inhibiting deposit ageing ferric hydroxide produced in the stage b), d) drying of composition produced at the stage.

EFFECT: production of phosphate adsorbent with lowered chlorine content of for oral and parenteral preparations for human or animals.

23 cl, 5 ex

FIELD: chemistry.

SUBSTANCE: natural mechanically milled iron (III) oxide of lamellar structure at least 50 wt %, preferentially 75 wt %, contains particles sized 10 mcm and less in amount, at least, 50 wt %, preferentially 70 wt %, particularly preferentially 90 wt %. The ratio of thickness to maximum diametre of iron (III) oxide plates is 1:5, preferentially 1:10. To produce such iron (III) oxide, it is mechanically milled in an impactor or a jet-type mill. Iron (III) oxide resulted from mechanical milling, is separated by size grade, e.g. by an air separator. Iron (III) oxide can be used in lacquering for a base corrosion protection, mechanical load protection, UV and IR protection, for decorative coating, and also as an extender for polymeric and ceramic materials.

EFFECT: possibility to prepare highly dispersed lamellar particles of natural iron oxide.

15 cl

FIELD: chemistry.

SUBSTANCE: method for preparation of iron oxide pigment from specularite includes specularite milling up to particle size more than 1 mm - 5 mm, after material concentration with magnetic separation up to content of α-Fe2O3 more than 60.0 wt % specularite is concentrated again. Concentrated specularite can serve as starting material for obtaining of pigment with dull luster consisting of iron mica with Fe2O3 content more than 85 wt % which includes thin scaly plates in amount more than 50 wt % and is featured with residue after wet sieving on a sieve with mesh size 63 mcm not more than 35 wt %.

EFFECT: invention allows to obtain pigments from specularite for protective-decorative and decorative coatings.

8 cl, 2 tbl, 5 ex

FIELD: chemistry.

SUBSTANCE: invention can be used in production of titanium dioxide when processing material which contains titanium and iron, for example ilmenite concentrates. The method of producing titanium dioxide involves the following steps: (a) reacting iron-containing titanium ore with an aqueous solution of NH4F at temperature 100-120°C, pressure of 1-2 bars and pH of approximately 6.5-7.0; (b) filtering the obtained aqueous suspension with subsequent separation into a precipitate fraction which contains ammonium fluoroferrates, and a filtrate fraction which contains ammonium fluorotitanates; (c) hydrolysis of the obtained filtrate fraction thereby obtaining a solid component which is ammonium fluorooxotitanate; (d) thermal hydrolysis of the solid component obtained at step (c).

EFFECT: high degree of utilisation of raw material, high output and whiteness of the product, as well as simplification of the process and reduction of amount of wastes.

17 cl, 4 dwg

FIELD: chemistry.

SUBSTANCE: method of titanium dioxide obtainment involves stages of (a) iron-containing titanium ore processing by aqueous solution of NH4F and/or NH4HF2; (b) filtration of obtained water suspension with further separation of solid sediment and aqueous solution containing titanium salts; (c) hydrolysis of the aqueous solution obtained; (d) filtration and pyrohydrolysis of solid sediment. Hydrolysis involves first stage at pH 7.0-8.5 and second stage at pH 10.0-13.0. Suspension obtained at the fist hydrolysis (c) stage is filtered to obtain aqueous solution containing titanium salt (NH4)2TiF6 with (NH4)3FeF6 concentration under 0.01 wt %, and sludge fraction containing ammonia oxyfluorotitanate and (NH4)3FeF6. Aqueous solution undergoes second hydrolysis (c) stage to obtain water suspension. Pyrohydrolysis involves first stage at maximum temperature of 450°C and second stage at maximum temperature of 1000°C.

EFFECT: waste-free obtainment of titanium dioxide resistant to UV radiation and not requiring additional grinding, reduction of power consumption.

22 cl, 1 dwg

FIELD: chemistry.

SUBSTANCE: invention can be used in making paint, construction and ceramic materials, glass, enamel, plastic and rubber. The iron oxide based pigment contains two fractions of iron (III) oxide. The first fraction has a plastic structure with particle size not smaller than 20 mcm. The second fraction consists of particles of different shapes with size not bigger than 20 mcm. The said components of the pigment are in the following ratio in wt %: iron (III) oxide of the first fraction with plastic structure 3-97, iron (III) oxide of the second fraction with particles of different shapes 97-3.

EFFECT: invention enables to obtain a grey coloured pigment with metallic lustre to red, increases corrosion resistance and wear resistance of the paint coatings, reduces opaqueness and oil absorption.

9 cl, 3 tbl, 3 ex

FIELD: chemistry.

SUBSTANCE: to obtain highly dispersed magnetically ordered iron (III) oxide, the γ-Fe2O3 magnetic phase is deposited in the presence of air for 24 hours at room temperature and atmospheric pressure from aqueous alkaline solutions iron (II) salts, cyclodextrins (CD) and a hypophosphorous acid salt, taken in molar ratio CD: Fe2+: NaH2PO2=1:100:100.

EFFECT: invention enables to obtain maghemite in highly dispersed state at room temperature at atmospheric pressure with increase in purity thereof.

2 dwg, 5 ex