GB2059410A - Process for producing hydrated iron oxide - Google Patents
Process for producing hydrated iron oxide Download PDFInfo
- Publication number
- GB2059410A GB2059410A GB8031809A GB8031809A GB2059410A GB 2059410 A GB2059410 A GB 2059410A GB 8031809 A GB8031809 A GB 8031809A GB 8031809 A GB8031809 A GB 8031809A GB 2059410 A GB2059410 A GB 2059410A
- Authority
- GB
- United Kingdom
- Prior art keywords
- goethite
- iron oxide
- treatment
- ageing treatment
- hydrated iron
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Withdrawn
Links
- UQSXHKLRYXJYBZ-UHFFFAOYSA-N Iron oxide Chemical compound [Fe]=O UQSXHKLRYXJYBZ-UHFFFAOYSA-N 0.000 title claims abstract description 22
- 238000000034 method Methods 0.000 title claims description 24
- 229910052598 goethite Inorganic materials 0.000 claims abstract description 27
- AEIXRCIKZIZYPM-UHFFFAOYSA-M hydroxy(oxo)iron Chemical compound [O][Fe]O AEIXRCIKZIZYPM-UHFFFAOYSA-M 0.000 claims abstract description 27
- 230000032683 aging Effects 0.000 claims abstract description 19
- 239000000725 suspension Substances 0.000 claims abstract description 19
- CWYNVVGOOAEACU-UHFFFAOYSA-N Fe2+ Chemical compound [Fe+2] CWYNVVGOOAEACU-UHFFFAOYSA-N 0.000 claims abstract description 18
- 229910001448 ferrous ion Inorganic materials 0.000 claims abstract description 15
- 238000010438 heat treatment Methods 0.000 claims abstract description 6
- 229960004887 ferric hydroxide Drugs 0.000 claims abstract description 4
- IEECXTSVVFWGSE-UHFFFAOYSA-M iron(3+);oxygen(2-);hydroxide Chemical compound [OH-].[O-2].[Fe+3] IEECXTSVVFWGSE-UHFFFAOYSA-M 0.000 claims abstract description 4
- 239000007864 aqueous solution Substances 0.000 claims description 8
- 150000001875 compounds Chemical class 0.000 claims description 6
- 239000002585 base Substances 0.000 description 12
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 description 9
- 238000004519 manufacturing process Methods 0.000 description 7
- 238000006386 neutralization reaction Methods 0.000 description 5
- 239000000843 powder Substances 0.000 description 5
- 239000011790 ferrous sulphate Substances 0.000 description 4
- 235000003891 ferrous sulphate Nutrition 0.000 description 4
- BAUYGSIQEAFULO-UHFFFAOYSA-L iron(2+) sulfate (anhydrous) Chemical compound [Fe+2].[O-]S([O-])(=O)=O BAUYGSIQEAFULO-UHFFFAOYSA-L 0.000 description 4
- 229910000359 iron(II) sulfate Inorganic materials 0.000 description 4
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 4
- KWYUFKZDYYNOTN-UHFFFAOYSA-M Potassium hydroxide Chemical compound [OH-].[K+] KWYUFKZDYYNOTN-UHFFFAOYSA-M 0.000 description 3
- -1 ferrous compound Chemical class 0.000 description 3
- SZVJSHCCFOBDDC-UHFFFAOYSA-N iron(II,III) oxide Inorganic materials O=[Fe]O[Fe]O[Fe]=O SZVJSHCCFOBDDC-UHFFFAOYSA-N 0.000 description 3
- 239000002245 particle Substances 0.000 description 3
- 239000000047 product Substances 0.000 description 3
- 150000003839 salts Chemical class 0.000 description 3
- 239000000243 solution Substances 0.000 description 3
- 239000007858 starting material Substances 0.000 description 3
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 description 2
- 229910021578 Iron(III) chloride Inorganic materials 0.000 description 2
- 230000015572 biosynthetic process Effects 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 238000001914 filtration Methods 0.000 description 2
- RBTARNINKXHZNM-UHFFFAOYSA-K iron trichloride Chemical group Cl[Fe](Cl)Cl RBTARNINKXHZNM-UHFFFAOYSA-K 0.000 description 2
- 239000006247 magnetic powder Substances 0.000 description 2
- 230000003647 oxidation Effects 0.000 description 2
- 238000007254 oxidation reaction Methods 0.000 description 2
- 239000002244 precipitate Substances 0.000 description 2
- 238000003756 stirring Methods 0.000 description 2
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 1
- 238000004438 BET method Methods 0.000 description 1
- 230000002378 acidificating effect Effects 0.000 description 1
- 239000003513 alkali Substances 0.000 description 1
- 229910001854 alkali hydroxide Inorganic materials 0.000 description 1
- 229910001860 alkaline earth metal hydroxide Inorganic materials 0.000 description 1
- 230000005587 bubbling Effects 0.000 description 1
- AXCZMVOFGPJBDE-UHFFFAOYSA-L calcium dihydroxide Chemical compound [OH-].[OH-].[Ca+2] AXCZMVOFGPJBDE-UHFFFAOYSA-L 0.000 description 1
- 239000000920 calcium hydroxide Substances 0.000 description 1
- 229910001861 calcium hydroxide Inorganic materials 0.000 description 1
- 150000004649 carbonic acid derivatives Chemical class 0.000 description 1
- 230000003197 catalytic effect Effects 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 239000008367 deionised water Substances 0.000 description 1
- 229910021641 deionized water Inorganic materials 0.000 description 1
- 229910001873 dinitrogen Inorganic materials 0.000 description 1
- 230000002708 enhancing effect Effects 0.000 description 1
- 239000012535 impurity Substances 0.000 description 1
- 238000010348 incorporation Methods 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- QSHDDOUJBYECFT-UHFFFAOYSA-N mercury Chemical compound [Hg] QSHDDOUJBYECFT-UHFFFAOYSA-N 0.000 description 1
- 229910052753 mercury Inorganic materials 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 239000000049 pigment Substances 0.000 description 1
- 238000005406 washing Methods 0.000 description 1
- 229910000859 α-Fe Inorganic materials 0.000 description 1
Classifications
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B5/00—Recording by magnetisation or demagnetisation of a record carrier; Reproducing by magnetic means; Record carriers therefor
- G11B5/62—Record carriers characterised by the selection of the material
- G11B5/68—Record carriers characterised by the selection of the material comprising one or more layers of magnetisable material homogeneously mixed with a bonding agent
- G11B5/70—Record carriers characterised by the selection of the material comprising one or more layers of magnetisable material homogeneously mixed with a bonding agent on a base layer
- G11B5/706—Record carriers characterised by the selection of the material comprising one or more layers of magnetisable material homogeneously mixed with a bonding agent on a base layer characterised by the composition of the magnetic material
- G11B5/70626—Record carriers characterised by the selection of the material comprising one or more layers of magnetisable material homogeneously mixed with a bonding agent on a base layer characterised by the composition of the magnetic material containing non-metallic substances
- G11B5/70642—Record carriers characterised by the selection of the material comprising one or more layers of magnetisable material homogeneously mixed with a bonding agent on a base layer characterised by the composition of the magnetic material containing non-metallic substances iron oxides
- G11B5/70678—Ferrites
- G11B5/70684—Ferro-ferrioxydes
- G11B5/70689—Magnetite
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01G—COMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSES C01D OR C01F
- C01G49/00—Compounds of iron
- C01G49/02—Oxides; Hydroxides
- C01G49/06—Ferric oxide [Fe2O3]
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2006/00—Physical properties of inorganic compounds
- C01P2006/12—Surface area
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2006/00—Physical properties of inorganic compounds
- C01P2006/42—Magnetic properties
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Inorganic Chemistry (AREA)
- Compounds Of Iron (AREA)
Abstract
A hydrated iron oxide comprising goethite as a main component is produced by subjecting alkaline suspension comprising ferric hydroxide as a main component to an ageing treatment e.g. at 20-70 DEG C or a combination of a heat-treatment (e.g. at 70-100 DEG C) followed by an ageing treatment. Ferrous ions are incorporated in said alkaline suspension.
Description
SPECIFICATION
Process for producing hydrated iron oxide
The present invention relates to a hydrated iron oxide comprising goethite as a main component.
Recently, goethite has been used in various fields such as in pigment as a source of ferrite and as a source of magnetic powders for magnetic recording media. The demand for goethite has therefore increased.
Various processes for producing a hydrated iron oxide comprising goethite as a main component by mass production methods and at economical cost have been proposed, in view of the increase in demand for goethite.
Goethite has been produced by adding an aqueous solution of a base at a concentration of 10 to 50% of the base sufficient for neutralization, to an aqueous solution of a ferrous compound such as ferrous sulfate to give a pH of about 4 and then bubbling air into the solution. The resulting goethite has not been of satisfactory quality because of the incorporation of relatively large amounts of impurities and the uneven configuration of particles which make the product unsatisfactory as a source of magnetic recording media.
A process for producing goethite by oxidation under alkaline conditions instead of under acidic conditions has been proposed to overcome the above-mentioned disadvantages, and goethite of high purity with an even configuration of particles has been obtained in this way. The process, however, has disadvantages. Since the oxidation is carried out under alkaline conditions, it requires about twice the amount of base required for neutralization of the ferrous compound. The use of a large amount of a base is disadvantageous from the point of increased production costs and the difficulty of water washing to remove the base after the reaction. There is also the problem that sodium hydroxide, the base most commonly used, is still produced in large quantities by the mercury process which is a source of pollution.
It has been proposed to produce goethite from a ferric compound instead of the ferrous compound as the starting material. In the latter process, a base is added to an aqueous solution of the ferric compound in an amount slightly in excess (by a few %) of the amount required for neutralization and the mixture is treated by ageing for a long period or treated in an autoclave at a high temperature such as 150 to 2000C for about 1 hour to obtain goethite. The resulting goethite is of high purity with an even configuration of particles and thus of high quality. It takes about 100 to 200 hours to obtain goethite of good industrial quality by the ageing treatment. The productivity is remarkably low. On the other hand, treatment in an autoclave is not suitable for economical industrial mass production.
The latter process for producing goethite using the ferric compound as the starting material has not therefore been satisfactory.
As discussed, the conventional processes for producing a hydrated iron oxide comprising goethite as a main component have not been satisfactory as industrial processes, and accordingly, some improvement has been required.
The inventor has studied processes for producing a high quality hydrated iron oxide comprising goethite as a main component by mass production and at economical cost, from the viewpoints of product source saving, pollution, energy saving, productivity and product quality. As a result, the inventor has concluded that certain process using the ferric compound as the starting material would be optimum for producing a hydrated iron oxide. In order to overcome the above-mentioned disadvantages, the inventor has concentrated on processes for producing goethite relatively quickly, without an autoclave and with only a modest consumption of base.
It is an object of the present invention to produce a hydrated iron oxide comprising goethite as a main component which is of high quality by a mass production process, rapidly and without an autoclave, and reducing the amount of base used for neutralization.
The present invention provides a process for producing a hydrated iron oxide comprising goethite as a main component by subjecting an alkaline suspension comprising ferric hydroxide as a main component to an ageing treatment or a combination of a heat-treatment followed by an ageing treatment, wherein ferrous ions are incorporated in said alkaline suspension.
It has been found that goethite of high quality can be obtained by heat-treatment for a relatively short time, if a small quantity of ferrous ions is incorporated in the suspension of ferric hydroxide.
The mechanism of the effect of the ferrous ion has not been clearly confirmed. It is however thought that the ferrous ion has a certain catalytic effect, enhancing the effect of the ageing and the following heat-treatment where applied.
In the process of the present invention, a small quantity of ferrous ions is incorporated in the aqueous solution of the ferric salt and a base is added to prepare an alkaline suspension. The ferrous ions can be incorporated in a form of an aqueous solution of ferrous ions or a compound containing ferrous ions, preferably at a ratio of
Fe2+/Fe3+ of 0.001 :1 to 0.05:1.
A suitable ferric salt is ferric chloride. The ferrous ions can suitably be incorporated in the form of ferrous sulfate. Other ferric salts and ferrous compounds can be used. The amount of the base added is preferably slightly in excess, for example, by 1 to 10% of the amount required for neutralization. The alkaline suspension has a reddish brown color. The most commonly used base is sodium hydroxide, but other alkali or alkaline earth metal hydroxides and carbonates such as potassium hydroxide and calcium hydroxide may be used.
The resulting reddish brown suspension is treated by ageing at a desired temperature with mild stirring. The ageing temperature is usually in a range of 20 to 700C.
The suspension has a reddish brown color and is changed through brown to yellow by the ageing treatment to complete the formation of goethite.
In the conventional process, an ageing treatment for 100 to 200 hours has to be carried out. By means of the present invention, the ageing time can be remarkably shortened. For example, the color of the suspension is changed to yellow at 600C in 20 hours.
When the color of the suspension is changed to brown in the ageing treatment, the temperature can be raised to a higher value such as 70 to 1 000C whereby the formation of goethite is completed in a shorter time.
The precipitate can be separated by filtration, washed with water and dried to obtain a fine acicular goethite powder.
By means of the process of the present invention, goethite of high quality can be produced by mass production, rapidly and at low cost. The industrial advantages of the process of the present invention are considerable.
The present invention will be illustrated by the following example and reference which are provided for the purposes of illustration only and are not to be construed as limiting the present invention.
EXAMPLE
In a solution of 36 g. of sodium hydroxide in 350 ml. of deionized water, 90 ml. of 35% aqueous solution of ferric chloride and 5 ml. of 1 M-aqueous solution of ferrous sulfate were added with stirring to prepare a reddish brown suspension of pH 12.5. The suspension was subjected to an ageing treatment at 6000 + 20C for 20 hours to obtain a yellow suspension.
The precipitate was separated by a filtration and washed with water and dried to obtain a yellow powder. According to the X-day diffraction, it was confirmed that the yellow powder is goethite. According to the measurement by the
BET method, the powder had a specific surface area of 72.4 m2/g.
The yellow powder was dehydrated at 60000 and reduced at 40000 in an atmosphere of nitrogen gas containing ethanol to obtain magnetite. The magnetite had magnetic characteristics of a coercive force of 428 Oe and a saturation magnetic moment per unit weight of 82.7 emu/g. The magnetite can be used as a magnetic powder for a magnetic recording medium.
REFERENCE
A reddish brown suspension obtained by the process of Example except that the solution of ferrous sulfate was not added, was treated by the ageing treatment at 6000 for 20 hours. The color of the suspension was changed to brown but was not changed to yellow.
Claims (6)
1. A process for producing a hydrated iron oxide comprising goethite as a main component by subjecting an alkaline suspension comprising ferric hydroxide as a main component to an ageing treatment or a combination of a heat-treatment followed by an ageing treatment, wherein ferrous ions are incorporated in said alkaline suspension.
2. A process according to Claim 1 wherein said ferrous ion is added at a ratio of Fe2+/Fe3+ of 0.001:1 to 0.05:1.
3. A process according to Claim 1 or Claim 2 wherein said ageing treatment is carried out at 20 to 7000.
4. A process according to any preceding Claim wherein said heat-treatment is carried out at 70 to 10000 when the color of said alkaline suspension has been changed from reddish brown to brown by said ageing treatment.
5. A process according to any preceding Claim wherein said ferrous ions are added in a form of-an aqueous solution containing ferrous ions or a compound containing ferrous ions.
6. A process according to Claim 1 substantially as herein described and exemplified.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP12635579A JPS5650122A (en) | 1979-10-02 | 1979-10-02 | Manufacture of iron oxide hydrate |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| GB2059410A true GB2059410A (en) | 1981-04-23 |
Family
ID=14933123
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB8031809A Withdrawn GB2059410A (en) | 1979-10-02 | 1980-10-02 | Process for producing hydrated iron oxide |
Country Status (4)
| Country | Link |
|---|---|
| JP (1) | JPS5650122A (en) |
| DE (1) | DE3037347A1 (en) |
| GB (1) | GB2059410A (en) |
| NL (1) | NL8005434A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0515749A2 (en) * | 1991-05-31 | 1992-12-02 | Toda Kogyo Corp. | Process for producing acicular goethite particles and acicular magnetic iron oxide particles |
| WO1996029288A1 (en) * | 1995-03-22 | 1996-09-26 | Pers Kemi As | Method of producing alpha-hematite hydrate from galvanising sludge |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6084416A (en) * | 1983-10-14 | 1985-05-13 | 日産自動車株式会社 | Clamp structure |
-
1979
- 1979-10-02 JP JP12635579A patent/JPS5650122A/en active Pending
-
1980
- 1980-10-01 NL NL8005434A patent/NL8005434A/en not_active Application Discontinuation
- 1980-10-02 GB GB8031809A patent/GB2059410A/en not_active Withdrawn
- 1980-10-02 DE DE19803037347 patent/DE3037347A1/en not_active Withdrawn
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0515749A2 (en) * | 1991-05-31 | 1992-12-02 | Toda Kogyo Corp. | Process for producing acicular goethite particles and acicular magnetic iron oxide particles |
| EP0515749A3 (en) * | 1991-05-31 | 1993-11-03 | Toda Kogyo Corp | Process for producing acicular goethite particles and acicular magnetic iron oxide particles |
| US5399278A (en) * | 1991-05-31 | 1995-03-21 | Toda Kogyo Corp. | Process for producing acicular goethite particles and acicular magnetic iron oxide particles |
| WO1996029288A1 (en) * | 1995-03-22 | 1996-09-26 | Pers Kemi As | Method of producing alpha-hematite hydrate from galvanising sludge |
Also Published As
| Publication number | Publication date |
|---|---|
| DE3037347A1 (en) | 1981-04-23 |
| NL8005434A (en) | 1981-04-06 |
| JPS5650122A (en) | 1981-05-07 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| WAP | Application withdrawn, taken to be withdrawn or refused ** after publication under section 16(1) |