Method of producing magnetoactive compound

FIELD: chemistry.

SUBSTANCE: invention can be used in inorganic chemistry. In order to obtain a magnetoactive compound by oxidative condensation of an iron (II) salt solution, condensation is carried out in the presence of nitrosated lignosulphonates in conditions of exposure to a magnetic field.

EFFECT: invention speeds up synthesis and enables to obtain a magnetoactive compound with high relative magnetic susceptibility.

1 tbl, 22 ex

 

The invention relates to methods for magnetic compounds. Nano-sized particles of magnetic compounds are the basis of magnetic fluids, possessing a unique combination of yield strength and ability to interact with the magnetic field. Their properties are determined by a set of properties of the hard magnetic phase, dispersion medium and stabilizer.

Mechanical dispersion of magnetite particles in ball mills for 1000 h was the first method of obtaining magnetic fluids. [Papell S.S. Low viskosity magnetic fluid obtaned by the colloidal suspension of magnetic particles. Patent USA No. 3215572, USA C1. 149-2. 1965] by wet mechanical grinding.

The method of obtaining magnetic compounds from natural mineral siderite [General and inorganic chemistry. - Karapetyants. SR Drakin - s], also has a low performance and, in addition, it is held at a high temperature.

In addition to poor performance deficiencies dispersion in a ball mill is the pollution of magnetic fluid products abrasion of the balls during operation of the mill and the large variation of particle sizes.

Kaiser perfected described by Papelon process and received a magnetic fluid in which the dispersion medium was water, aromatic hydrocarbons and ethers [R. Kaiser, G. Miskolczy // J.Appl. Phys., 1970, V. 41, N3, P.1064-102. Kaiser R. Ferrofluid composition. Patent USA No. 3700595, Int. C1. H01F 1/10, 1972].

Magnetic particles of colloidal dimensions can be formed through condensation of individual molecules. The size of the resulting particles is significantly affected by the conditions of condensation, therefore, to obtain colloidal particles of magnetic materials use different variants of the method.

Chemical reaction (1) is the basis of many methods of condensation magnetic connections:

.

For example, to obtain magnetite 10%solutions of FeCl2·4H2O and FeCl3·6H2O taken in such quantities that the ratio of saltsFe3+/Fe2+F was 2 to 1, mixed at 70°C with constant stirring to add an excess of 10%NaOH solution. To limit the size of the particles of the condensation is carried out at intensive stirring [Elmore W.. // Phys. Rew., 1938, V. 54, P.309].

Replacement by condensation of magnetite sodium hydroxide to ammonium hydroxide allows the coprecipitation of salts at 25...40°C. (U.S. Pat. The USSR№568598, 861321, 966015, 978860).

For stabilization in the aquatic environment of the magnetite particles with an average size of about 10 nm, obtained by a chemical condensation, Neil proposed to use sodium lignosulphonate. Insufficient the AMI method are the necessity of using two iron salts and prolonged exposure at elevated temperatures. The product obtained at low temperatures, has no magnetic activity. [Neal J.A. Clarification process. Patent USA 4088779 C02B 1/20, 1978.; Neal J.A. Clarification process. Patent USA 4110208 C02B 1/20, 1978].

In addition, there is a method, in accordance with which of the salt solution of iron (II) precipitated carbonate of iron (II), which is further for 1 h and subjected to an oxidizing treatment at a temperature of 55...60°C. as a result, the carbonate of iron(II) becomes magnetized magnetite. The reaction product is washed by decantation until pH 7 [U.S. Pat. Of the Russian Federation No. 2230705. IPC7C01G 49/08. The method of obtaining magnetic connection // Belikov VG, Coregen A.G., Sajeev SO, Zulfikarov I.N. Application: 2000109795/02, 19.04.2000. Published: 20.06.2004].

Closest to the proposed method is to obtain pure black pigment iron oxide (patent CN 102139927 High-purity iron oxide black pigment and production method thereof) sulphate iron (II) in alkaline medium. The method is as follows. An aqueous solution of FeSO4originally alkalinized with sodium hydroxide solution at normal temperature and incubated for 0.5...2 hours while controlling the pH 10,5 10.... Next, perform the oxidation with atmospheric oxygen at a temperature of 90 to 97°C for 1 h After completion of the oxidation of the pigment remove impurities heavy metals, washed on a filter press and dried.

The disadvantage of this method is large, the duration of the synthesis of magnetic connection.

The aim is to accelerate the synthesis of magnetic connection. This is achieved by condensation of magnetic compounds from a solution of iron salts produced under the influence of a magnetic field.

The method is implemented as follows. Sodium salt of iron (II) is added to the calculation, the number nitrosated lignosulphonic acid, the resulting solution podslushivaet and maintained under the action of an external magnetic field. Eye-catching turquoise precipitate quickly compacted and after some time turns into a magnetic connection with high relative magnetic susceptibility.

Example 1. For the deposition of magnetic compounds were mixed with 10 ml of a solution nitrosated lignosulfonate, a concentration of 0.74 mg/ml, 0.8 ml of a solution of sulphate of iron (II)concentration of 27.8 mg/ml, and 2 ml of NaOH solution, the concentration of 40 g/L.

The nitrosation of lignosulfonate was carried out as follows. In a volumetric flask with a capacity of 200 ml was made 8 ml source lignosulfonate, a concentration of 1.86 g/l, 7.5 ml of a solution of sodium nitrite, the concentration of 2.5 g/l (consumption of sodium nitrite in relation to the lignosulfonate was 12.6%) and 1 ml of nitric acid concentration of 10%, the volume of solution was brought to the mark with distilled water. The nitrosation reaction was carried out for 60 minutes

The tube with the reaction mixture maintained at a constant magnet for 15 minutes was Measured volume of sediment and OMV. The volume of sediment expressed in percentage of the total volume of the reaction mixture reached 90.7%, OMV 14.8 g/gFe.

Example 2. The deposition of the magnetic compound was carried out under the conditions of example 1, characterized in that the measuring tube with the reaction mixture maintained at a constant magnet for 30 minutes was Measured volume of sediment and OMV. The volume of sediment expressed in percentage of the total volume of the reaction mixture, made up 92.9%, OMV to 17.6 g/gFe.

Example 3. The deposition of the magnetic compound was carried out under the conditions of example 1, characterized in that the measuring tube with the reaction mixture maintained at a constant magnet for 60 minutes was Measured volume of sediment and OMV. The volume of sediment expressed in percentage of the total volume of the reaction mixture, 94.3%, OMV 22.1 g/gFe.

Example 4. The deposition of the magnetic compound was carried out under the conditions of example 1, characterized in that the measuring tube with the reaction mixture maintained at a constant magnet for 90 minutes Measured the amount of sediment and OMV. The volume of sediment expressed in percentage of the total volume of the reaction mixture, 94.3%, OMV and 24.1 g/gFe.

Example 5. The deposition of the magnetic compound was carried out under the conditions of example 1, characterized in that the tube with the reaction mixture maintained at a constant magnet for 120 minutes Measured the amount of sediment and OMV. The volume of sediment expressed in percentage of the total volume of the reaction mixture, 94.3%, OMV of 26.6 g/gFe. The precipitate was acquired properties of magnetic fluid.

Example 6. The deposition of the magnetic compound was carried out under the conditions of example 1, characterized in that the measuring tube with the reaction mixture maintained at a constant magnet for 180 minutes was Measured volume of sediment and OMV. The volume of sediment expressed in percentage of the total volume of the reaction mixture, 94.3%, OMV 27,1 g/gFe. The precipitate was acquired properties of magnetic fluid.

Example 7. The deposition of the magnetic compound was carried out under the conditions of example 1, characterized in that the measuring tube with the reaction mixture maintained at a constant magnet for 1200 minutes Measured the amount of sediment and OMV. The volume of sediment expressed in percentage of the total volume of the reaction mixture, 94.3%, OMV of 37.3 g/gFe. The precipitate was acquired properties of magnetic fluid.

Example 8. The deposition of the magnetic compound was carried out under the conditions of example 1, characterized in that the condensation MS was performed without exposure to a magnetic field within 15 minutes Measured the amount of sediment and OMV. The volume of sediment expressed in percentage of the total volume of the reaction mixture amounted to 77,9%, OMV 7.6 g/gFe.

Example 9. The deposition of the magnetic compound was carried out the conditions of example 8, characterized in that the measurement of the volume of sediment and OMV conducted through 30. The volume of sediment expressed in percentage of the total volume of the reaction mixture reached 84.2%, OMV 11.3 g/gFe.

Example 10. The deposition of the magnetic compound was carried out under the conditions of example 8, characterized in that the measurement of the volume of sediment and OMV conducted through 60. The volume of sediment expressed in percentage of the total volume of the reaction mixture, amounted to 87.1%, OMV to 18.3 g/gFe. The precipitate was acquired properties of magnetic fluid.

Example 11. The deposition of the magnetic compound was carried out under the conditions of example 8, characterized in that the measurement of the volume of sediment and OMV conducted through 90. The volume of sediment expressed in percentage of the total volume of the reaction mixture, amounted to 88.6%, OMV 21,4 g/gFe. The precipitate was acquired properties of magnetic fluid.

Example 12. The deposition of the magnetic compound was carried out under the conditions of example 8, characterized in that the measurement of the volume of sediment and OMV conducted through 120. The volume of sediment expressed in percentage of the total volume of the reaction mixture, amounted to 88.6%, OMV of 23.8 g/gFe. The precipitate was acquired properties of magnetic fluid.

Example 13. The deposition of the magnetic compound was carried out under the conditions of example 8, characterized in that the measurement of the volume of sediment and OMV conducted through 180. The volume of sediment expressed in percentage of the total reactio the Noah mixture, amounted to 88.6%, OMV and 26.1 g/gFe. The precipitate was acquired properties of magnetic fluid.

Example 14. The deposition of the magnetic compound was carried out under the conditions of example 8, characterized in that the measurement of the volume of sediment and OMV conducted through 1200. The volume of sediment expressed in percentage of the total volume of the reaction mixture was 26.1%, OMV 30,8 g/gFe. The precipitate was acquired properties of magnetic fluid.

Example 15. The deposition of the magnetic compound was carried out under the conditions of example 1, characterized in that the nitrosation reaction of lignosulfonate was carried out for 180 minutes

The tube with the reaction mixture maintained at a constant magnet for 15 minutes was Measured volume of sediment and OMV. The volume of sediment expressed in percentage of the total volume of the reaction mixture amounted to 90.0%, OMV of 13.2 g/gFe.

Example 16. The deposition of the magnetic compound was carried out under the conditions of example 15, characterized in that the measuring tube with the reaction mixture maintained at a constant magnet for 30 minutes was Measured volume of sediment and OMV. The volume of sediment expressed in percentage of the total volume of the reaction mixture, made up 92.9%, OMV 17.1 g/gFe. The precipitate was acquired properties of magnetic fluid.

Example 17. The deposition of the magnetic compound was carried out under the conditions of example 15, characterized in that the measuring tube with the reaction mixture to remove ivali permanent magnet within 60 minutes Measured the amount of sediment and OMV. The volume of sediment expressed in percentage of the total volume of the reaction mixture, 94.3%, OMV of 20.9 g/gFe. The precipitate was acquired properties of magnetic fluid.

Example 18. The deposition of the magnetic compound was carried out under the conditions of example 15, characterized in that the measuring tube with the reaction mixture maintained at a constant magnet for 90 minutes Measured the amount of sediment and OMV. The volume of sediment expressed in percentage of the total volume of the reaction mixture, 94.3%, OMV to 22.9 g/gFe. The precipitate was acquired properties of magnetic fluid.

Example 19. The deposition of the magnetic compound was carried out under the conditions of example 15, characterized in that the condensation MS was performed without exposure to a magnetic field within 15 minutes Measured the amount of sediment and OMV. The volume of sediment expressed in percentage of the total volume of the reaction mixture, was 61.4%, OMV 4.1 g/gFe.

Example 20. The deposition of the magnetic compound was carried out under the conditions of example 19, characterized in that the measuring tube with the reaction mixture maintained at a constant magnet for 30 minutes was Measured volume of sediment and OMV. The volume of sediment expressed in percentage of the total volume of the reaction mixture amounted to 77.1 percent, OMV 5.9 g/gFe.

Example 21. The deposition of the magnetic compound was carried out under the conditions of example 19, characterized in that the measurements of the test tube with the reaction mixture maintained at a constant magnet for 60 minutes Measured the amount of sediment and OMV. The volume of sediment expressed in percentage of the total volume of the reaction mixture, 82.9%, OMV 8,9 g/gFe. The precipitate was acquired properties of magnetic fluid.

Example 22. The deposition of the magnetic compound was carried out under the conditions of example 19, characterized in that the measuring tube with the reaction mixture was stirred for permanent magnet within 90 minutes From the measured volume of sediment and OMV. The volume of sediment expressed in percentage of the total volume of the reaction mixture amounted to 85.7%, OMV 11.2 g/gFe. The precipitate was acquired properties of magnetic fluid.

The results obtained during the synthesis of magnetic compounds are summarized in the table, from the data which shows that the proposed solution can significantly accelerate the synthesis of magnetic connection.

ExampleCondensation conditionsτ minIndicators
the amount of sludge, % of totalOMV, g/gFeappearance
1under the action of an external magnetic field1590,7 14,8the precipitate
2under the action of an external magnetic field3092,917,6the precipitate
3under the action of an external magnetic field6094,322,1the precipitate
4under the action of an external magnetic field9094,324,3the precipitate
5under the action of an external magnetic field12094,326,6liquid
6under the action of an external magnetic field18094,327,1liquid
7under the action of an external magnetic field120094,3 37,3liquid
8natural1577,97,6the precipitate
9natural3084,311,2the precipitate
10natural6087,118,3liquid
11natural9088,621,4liquid
12natural12088,623,8liquid
13natural18088,626,1liquid
14the EU is the natural enemy 120088,630,8liquid
15under the action of an external magnetic field1590,013,2the precipitate
16under the action of an external magnetic field3092,917,1liquid
17under the action of an external magnetic field6094,320,9liquid
18under the influence9094,322,9liquid
the external magnetic field
19natural15 61,44,1the precipitate
20natural3077,15,9the precipitate
21natural6082,98,9liquid
22natural9085,711,2liquid

The method of obtaining magnetic compounds by oxidative condensation of a salt solution of iron (II), characterized in that the condensation is carried out in the presence of nitrosated lignosulfonate under the influence of a magnetic field.



 

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