CN1861527A - Preparation process of Fe3O4 magnetic powder - Google Patents
Preparation process of Fe3O4 magnetic powder Download PDFInfo
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- CN1861527A CN1861527A CN 200610078078 CN200610078078A CN1861527A CN 1861527 A CN1861527 A CN 1861527A CN 200610078078 CN200610078078 CN 200610078078 CN 200610078078 A CN200610078078 A CN 200610078078A CN 1861527 A CN1861527 A CN 1861527A
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Abstract
A process for preparing the magnetic Fe3O4 powder with high thermal stability, dispersity and purity includes such steps as oxidizing the colloid of ferrous hydroxide to obtain Fe3O4, adding modifier chosen from silicate and aluminum salt, and surficial modifying reaction.
Description
Technical field
The present invention relates to Z 250 (Fe
3O
4) preparation technology of magnetic, relate in particular to the high-grade Fe that improves performance by surface modification
3O
4The preparation method of magnetic.
Background technology
Fe
3O
4Magnetic is the main raw material of the used single component magnetic photographic developer of picture and text output equipments such as duplicating machine, laser printer, facsimile recorder.Fe
3O
4The quality of magnetic is bigger to the performance impact of used photographic developer such as duplicating machine, laser printer, facsimile recorder.Modern picture and text output equipment resolving power is very high, and this needs, and granularity is ultra-fine, the photographic developer narrow, good dispersity that distributes matches, therefore, and also just to Fe as the photographic developer raw material
3O
4Aspects such as magnetic magnetic property, size-grade distribution, thermostability have proposed higher requirement.
At present, with the preparation method's of magnetic research more record has been arranged for magnetic recording, but at duplicating machine, laser printer imaging Fe
3O
4The research of magnetic is less.Though introduced the preparation method of some magnetic magnetics in some report, for example, a kind of method for preparing high magnetic magnetic is disclosed in the Chinese patent application 03131854.1, the magnetic pattern of this method preparation is the lower cube of coercive force, can be used as to produce the photographic developer that duplicating machine, facsimile recorder are used.Usual method all is to implement oxidation by the ferrous hydroxide colloid being added oxygenant, becomes the Z 250 product, again through separate, dry and be crushed into needed magnetic.One of problem that exists in actual production process is that the Z 250 thermostability is bad, meets high temperature meeting over oxidation, influence the character of magnetic, so the dry general requirement of magnetic is controlled at 40-45 ℃, drying efficiency is lower, and the high temperature of environment for use also can influence the performance of magnetic.And, present method prepares ferroferric oxide magnetic powder without any surface treatment, because the magnetic water-absorbent is strong, easily reunite, if with this magnetic powders photographic developer, because magnetic can not homodisperse in resin, must cause the small part magnetic exposed not by resin-coated, in the crushing process of preparation photographic developer and in the use of photographic developer behind the dress box, exposed magnetic is because friction is easy to oxidized like this, reduce the quality of photographic developer, influence result of use.In addition, can not realize artificially controlling the pattern of magnetic and magnetic properties etc. in the process of present disclosed preparation magnetic, also influence the range of application of magnetic.
Summary of the invention
Technical problem to be solved by this invention is exactly to propose a kind of improving one's methods of ferroferric oxide magnetic powder that prepare, by magnetic is implemented surface modification and controlled production process and condition, can prepare thermostability height, good dispersity and regular shape, even-grained puron magnetic.
The method for preparing ferromagnetic powder that the present invention proposes, comprise that the synthetic Z 250 of hydrogen oxide ferrous iron oxide colloid reaches the process of oxidation products being implemented modification Processing of Preparation magnetic, wherein, described oxidising process comprises that the pH value of controlling reaction system is 5-14, and after generating Z 250, oxidising process adds surface-modifying agent, oxidation products is carried out modification handle back enforcement drying, described surface-modifying agent comprises silicate and/or aluminium salt, and its add-on is respectively the 1-10wt% of total iron amount in the system.
The method according to this invention, the ferroferric oxide magnetic powder that obtains is through surface modification treatment, promptly, in system, add silicate and/or aluminium salt and implement the modification processing, the thermostability of magnetic has improved greatly, help the operation of drying process, for example can improve drying efficiency by improving drying temperature.So the drying temperature of magnetic can be at 40-130 ℃ in the inventive method, preferred drying temperature can be at 100-130 ℃.
When the Z 250 in the oxidizing reaction system is implemented surface modification treatment, except adding above-mentioned silicate and/or aluminium salt, can also add suitable organic titanate, improve the dispersiveness of magnetic by improving hydrophobic nature, add-on is the 1-5wt% of total iron amount in the system.
According to the concrete purposes of prepared magnetic, can also implement further modification, for example, in oxidation reaction process, add phosphoric acid salt, help crystal grain thinning, improve the uniformity coefficient of magnetic.This magnetic can be used to make magnetic rheological liquid, and the add-on of phosphoric acid salt properties-correcting agent is the 1-14wt% of ferrous ion total amount in the system.
According to the proposed method, ferrous hydroxide colloidal oxidising process is to finish by add oxygenant in system, can control ferrous rate of oxidation by the add-on of controlled oxidation agent in the reaction process, preferably, total mole number based on ferrous ion in the system, making in the reaction system ferrous rate of oxidation is 20-50% per hour (that is, the per hour oxidized ferrous mole number of control is the 20-50% of ferrous iron total mole number in the system).When about 67% of ferrous iron total amount in the system is oxidized to ferric iron, stop the adding of oxygenant.
The method according to this invention also comprises copperas solution and the alkali reaction synthetic ferrous hydroxide colloidal process of pH value for 1-4.5 that adopt.The preferred pH value that adopts is copperas solution and the synthetic ferrous hydroxide colloid of alkali reaction of 2-3.
Described ferrous sulfate can be from any approach, for example is purchased or synthetic voluntarily, and reaction and condition control between itself and the alkali are common practise and technology, can use alkaloid substance commonly used such as sodium hydroxide, potassium hydroxide, ammoniacal liquor in actual production.
In actual production, method of the present invention can be specific as follows:
Adopting the pH value is copperas solution and the synthetic ferrous hydroxide colloid of alkali reaction of 1-4.5;
Add oxygenant generation oxidizing reaction at 60-100 ℃ in reaction system, the pH value of controlling this reaction system is 5-14, and make ferrous rate of oxidation be 20-50% per hour;
When about 67% of ferrous iron total amount in this oxidizing reaction system is oxidized to ferric iron, in system, add surface-modifying agent, described surface-modifying agent comprises silicate and/or aluminium salt, its add-on is respectively the 1-10wt% of total iron amount in the system, the hierarchy of control is weak acid or weakly alkaline scope, stirs 1-5 hour, to the system solid-liquid separation, collect magnetic, after cleaning 100-130 ℃ of drying.
When implementing oxidizing reaction, it is oxygenant that the present invention can adopt oxygen or air, controls ferrous rate of oxidation by adjusting air flow.
Aforesaid method adds silicate and/or aluminium salt in oxidation products, can effectively improve the thermostability of magnetic, and preferred process is:
Add silicate (for example water glass, Starso, the positive own ester of silicic acid and silane etc.) earlier, the pH value of the hierarchy of control is 7-10, and 80-90 ℃ was stirred 1-3 hour, and this process mesosilicic acid salt can be coated on the magnetic surface more lentamente and form dense coating layer; Add aluminium salt (for example Tai-Ace S 150 and aluminum chloride etc.) then, the pH value of the hierarchy of control is 5-7, and 60-75 ℃ was stirred 1-3 hour, and the magnetic surface is slowly coated once more, forms fine and close aluminium salt coating layer.Through such processing, magnetic has very high thermostability, can stand the drying treatment under the comparatively high temps.
More preferably, magnetic through silicate and/or aluminum salt modified after, under 60-70 ℃ of temperature condition, add the organic titanate that is equivalent to the 1-5wt% of total iron amount in the system, for example metatitanic acid four isobutyl esters etc. continue insulation 1-3 hour, and the dispersiveness of magnetic is significantly improved, in preparation ink powder process, help the abundant dispersion of magnetic in resin.
According to specific embodiments of the present invention, can also in described oxidizing reaction system, add phosphoric acid salt, for example, sodium phosphate, Sodium phosphate dibasic, sodium-metaphosphate etc., the granularity of magnetic is more tiny, even after the superphosphate modification, can be used for the making of magnetic rheological liquid, phosphatic add-on is the 1-14wt% of ferrous ion total amount in the system.
Preparation in accordance with the present invention, ferrous sulfate can be by iron-bearing material and vitriolic prepared in reaction, and described iron-bearing material is various iron ore raw materials, iron scale, scrap iron etc.For example, the vitriol oil slowly joined be mixed with sulphuric acid soln in the deionized water, under keeping 70-100 ℃ iron-bearing material is slowly added, react after 2-8 hour, if desired, can add micro-treatment agent makes elements such as silicon in the raw material, calcium, magnesium, titanium, manganese form water-insoluble, make the iron in the raw material be converted into ferrous iron simultaneously, filter this system and obtain copperas solution, control its pH value at 1-4.5, preferably 2-3 is used for subsequent preparation process.
Based on above narration, the solution of the present invention is implemented to have the following advantages:
Fe
3O
4Magnetic with alkali and copperas solution in reactor through the oxidation preparation, the pH value by the control reaction system in the preparation process, and the rate of oxidation of controlling ferrous ion in the reaction system is at 20-50% per hour in the scope, the Fe for preparing
3O
4Magnetic is purity height, regular shape, epigranular not only, and can prepare the magnetic of multiple shapes such as sphere, cube and octahedron as required.Especially by inorganic and organic composite modified processing, control effective operational condition, form fine and close coating layer, make that the thermostability of magnetic improves, dispersiveness is better on the magnetic powder particle surface to the magnetic surface.Therefore, the Fe for preparing with the technology of the present invention
3O
4Magnetic purity reaches more than 98%, can be used as the raw material of duplicating machine, laser printer and facsimile recorder photographic developer, and the photographic developer that makes not only blackness height, level is good, and resolving power and contrast gradient are all very high.
Embodiment
Below describe the enforcement of technical solution of the present invention and the beneficial effect that is produced in detail by specific embodiment, understand substantive features of the present invention better to help the reader, but do not constitute any restriction protection domain of the present invention.
Embodiment 1
The 680L vitriol oil (95%) is slowly joined in the deionized water, be mixed with about 10m
3Sulphuric acid soln, the iron ore raw material with 900Kg joins in this sulphuric acid soln then, reaction is 2 hours under about 80 ℃ temperature, adds an amount of propionic acid acid amides medicament, makes elements such as silicon, calcium, magnesium, titanium form water-insoluble; System is filtered, obtain copperas solution, its concentration is about 85g/L (in iron), and the pH value of solution is 2.5.
Afterwards, add ammonia soln and above-mentioned copperas solution successively in reactor, the mol ratio of controlling both is 2: 1.The pH value of control reaction system is about 6.5, keeps reaction and obtains the ferrous hydroxide colloid.
Under 85 ℃ temperature with 25m
3The flow of/h is blowing air in this reactor, when being oxidized to ferric iron, about 67% of ferrous iron total amount in the system stops bubbling air, the pH that adjusts this oxidation system is about 8.5, keep the temperature about 85 ℃, in solution, add the Starso that is equivalent to total iron amount 8wt%, stirred about 2 hours; Adjusting pH then is about 6.5, suitably cools to about 70 ℃, adds the Tai-Ace S 150 that is equivalent to total iron amount 6wt% again, stirs about 2 hours; Add organic metatitanic acid four isobutyl ester 1wt% (in total iron amount) at last, 60 ℃ are incubated 2 hours.
Afterwards,, use the washed with de-ionized water solid phase, make that soluble cation content is lower than 0.02% in the final magnetic, in temperature is baking oven about 120 ℃, dry above-mentioned system solid-liquid separation.
At last, disperse, obtain Fe of the present invention with pulverizer
3O
4Magnetic.
This magnetic characteristic sees Table 1.
Embodiment 2
Method according to embodiment 1 prepares copperas solution, adds ammonia soln and this copperas solution successively in reactor, and the mol ratio of controlling both is 2: 1, and the pH value of control solution is 9-10, obtains the ferrous hydroxide colloid.
Under 85 ℃ temperature with 5m
3The flow of/h is logical oxygen in reactor, stop aerating oxygen when about 67% of ferrous iron total amount in the system is oxidized to ferric iron, the pH that adjusts this oxidation system is about 8, keeps the temperature about 85 ℃, in solution, add the Starso that is equivalent to total iron amount 8wt%, stirred about 2 hours; Adjusting pH then is about 6, suitably cools to about 75 ℃, adds the aluminum chloride that is equivalent to total iron amount 6wt% again, stirs about 2 hours; Add organic metatitanic acid four isobutyl ester 2wt% (in total iron amount) at last, 60 ℃ are incubated 2 hours.
Afterwards,, use the washed with de-ionized water solid phase, make that soluble cation content is lower than 0.02% in the final magnetic, in temperature is baking oven about 110 ℃, dry above-mentioned system solid-liquid separation.
At last, disperse, obtain Fe of the present invention with pulverizer
3O
4Magnetic.
The magnetic characteristic sees Table 1.
Embodiment 3
Method according to embodiment 1 prepares copperas solution, and perhaps other modes or be purchased ferrous sulfate are mixed with pH and are 2.5 solution, add sodium hydroxide solution and copperas solution successively in reactor, and the mol ratio of controlling both is 2.3: 1.The pH value of control solution is 13-14, obtains the ferrous hydroxide colloid.
Under 85 ℃ temperature with 5m
3The flow of/h is logical oxygen in reactor, stops aerating oxygen when about 67% of ferrous iron total amount in the system is oxidized to ferric iron.The pH that adjusts this oxidation system is 9, keeps the temperature about 85 ℃, adds the Starso that is equivalent to total iron amount 8wt% in solution, stirs about 2 hours; Adjusting pH then is 7, suitably cools to about 75 ℃, adds the aluminum chloride that is equivalent to total iron amount 6wt% again, stirs about 2 hours; Add organic metatitanic acid four isobutyl ester 1.5wt% (in total iron amount) at last, 60 ℃ are incubated 2 hours.
Afterwards,, use the washed with de-ionized water solid phase, make soluble cation content in the final magnetic be lower than 0.02% and in temperature is 120 ℃ baking oven, dry above-mentioned system solid-liquid separation.
At last, disperse, obtain Fe of the present invention with pulverizer
3O
4Magnetic.
The magnetic characteristic sees Table 1.
Embodiment 4
Method according to embodiment 1 prepares copperas solution, and perhaps other modes or be purchased ferrous sulfate are mixed with pH and are 2.5 solution, add sodium hydroxide solution and copperas solution successively in reactor, and the mol ratio of controlling both is 2.3: 1.Add the sodium phosphate that is equivalent to the about 9wt% of ferrous ion total amount, the pH value of control solution is 13-14, obtains the ferrous hydroxide colloid.
Under 85 ℃ temperature with 25m
3The flow of/h blowing air in reactor stops aerating oxygen when about 67% of ferrous iron total amount in the system is oxidized to ferric iron; The pH that adjusts this oxidation system is 7-10, keeps the temperature about 85 ℃, adds the water glass that is equivalent to total iron amount 6wt%, stirs about 2 hours; Adjusting pH then is 5-7, cools to about 75 ℃, adds the Tai-Ace S 150 that is equivalent to total iron amount 7wt% again, stirs about 2 hours; Add the about 3.5wt% of organic metatitanic acid four isobutyl esters (in total iron amount) at last, 60 ℃ are incubated 2 hours.
Afterwards,, use the washed with de-ionized water solid phase, make that soluble cation content is lower than 0.02% in the final magnetic above-mentioned system solid-liquid separation.In being 110 ℃ baking oven, temperature dries.
At last, disperse, obtain Fe of the present invention with pulverizer
3O
4Magnetic.
The magnetic characteristic sees Table 1.
Table 1
| Embodiment | The magnetic shape | The magnetic blackness | Coercive force (Oe) | Specific saturation magnetization (emu/g) | Mean particle size (μ m) | The pH value | FeO content (%wt) |
| Example 1 | Spherical | 1.40 | 56 | 88.40 | 0.25 | 6.7 | 26.3 |
| Example 2 | Cubes | 1.35 | 85 | 92.40 | 0.30 | 7.2 | 28.2 |
| Example 3 | Octahedra | 1.36 | 125 | 85.50 | 0.25 | 5.6 | 27.8 |
| Example 4 | Octahedra | 1.35 | 150 | 82.40 | 0.15 | 5.5 | 26.8 |
Claims (13)
1, Fe
3O
4The preparation method of magnetic, comprise that the synthetic Z 250 of hydrogen oxide ferrous iron oxide colloid reaches the process of oxidation products being implemented modification Processing of Preparation magnetic, wherein, described oxidising process comprises that the pH value of controlling reaction system is 5-14, and after generating Z 250, oxidising process adds surface-modifying agent, oxidation products is carried out modification handle back enforcement drying, described surface-modifying agent comprises silicate and/or aluminium salt, and its add-on is respectively the 1-10wt% of total iron amount in the system.
2, preparation method according to claim 1, wherein, the drying temperature of described magnetic is 40-130 ℃.
3, preparation method according to claim 1, wherein, the surface-modifying agent of adding also includes organic titanate, and its add-on is the 1-5wt% of total iron amount in the system.
4, according to claim 1 or 3 described preparation methods, wherein, in oxidising process, also add phosphoric acid salt, add-on is the 1-14wt% of ferrous ion total amount in the system.
5, preparation method according to claim 1, wherein, in the oxidizing reaction with air or oxygen as oxygenant.
6, preparation method according to claim 5, wherein, the amount of controlled oxidation agent in the oxidizing reaction, make in the reaction system ferrous rate of oxidation be 20-50% per hour.
7, preparation method according to claim 1 also comprises copperas solution and the alkali reaction synthetic ferrous hydroxide colloidal process of pH value for 1-4.5 that adopt.
8, preparation method according to claim 7, wherein, adopting the pH value is copperas solution and the synthetic ferrous hydroxide colloid of alkali reaction of 2-3.
9, preparation method according to claim 1, comprising:
Adopting the pH value is copperas solution and the synthetic ferrous hydroxide colloid of alkali reaction of 1-4.5;
Add oxygenant generation oxidizing reaction at 60-100 ℃ in reaction system, the pH value of controlling this reaction system is 5-14, make ferrous rate of oxidation be 20-50% per hour; When 67% of ferrous iron total amount in this oxidizing reaction system is oxidized to ferric iron, in system, add surface-modifying agent, described surface-modifying agent comprises silicate and/or aluminium salt, its add-on is respectively the 1-10wt% of total iron amount in the system, the hierarchy of control is weak acid or weakly alkaline scope, stirs 1-5 hour;
To the system solid-liquid separation, collect magnetic, after cleaning 100-130 ℃ of drying.
10, preparation method according to claim 9, wherein, the process that adds surface-modifying agent is:
Add silicate earlier, the pH value of the hierarchy of control is 7-10, stirs 1-3 hour at 80-90 ℃;
Add aluminium salt then, the pH value of the hierarchy of control is 5-7, stirs 1-3 hour at 60-75 ℃.
11, according to claim 9 or 10 described preparation methods, wherein, magnetic through silicate and/or aluminum salt modified after, under 60-70 ℃ of temperature condition, add the organic titanate be equivalent to the 1-5wt% of total iron amount in the system and carry out surface treatment.
12,, comprise also wherein in described oxidizing reaction system adding phosphoric acid salt that add-on is the 1-14wt% of ferrous ion total amount in the system according to claim 9 or 11 described preparation methods.
13, according to claim 1 or 9 described preparation methods, wherein, the pattern of prepared ferroferric oxide magnetic powder comprises sphere, cubes or octahedron.
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Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102390872A (en) * | 2011-08-09 | 2012-03-28 | 东南大学 | Preparation method of micrometer-scale cubic ultrodispersed ferroferric oxide particles |
| CN105800696A (en) * | 2016-03-02 | 2016-07-27 | 天津大学 | Method for preparing high-magnetism ferroferric oxide powder from steel pickling waste liquid |
| CN107200362A (en) * | 2017-06-26 | 2017-09-26 | 杭州明兴化工有限公司 | A kind of method that pure oxygen oxidizing process produces iron oxide black |
| CN108238645A (en) * | 2016-12-26 | 2018-07-03 | 惠州市华阳光学技术有限公司 | A kind of preparation method of paramagnetic nanoparticles particle |
| CN110669565A (en) * | 2019-09-10 | 2020-01-10 | 浙江中博润滑油有限公司 | Preparation method of nano modified transformer oil with high breakdown voltage |
-
2006
- 2006-04-29 CN CN 200610078078 patent/CN1861527A/en active Pending
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102390872A (en) * | 2011-08-09 | 2012-03-28 | 东南大学 | Preparation method of micrometer-scale cubic ultrodispersed ferroferric oxide particles |
| CN105800696A (en) * | 2016-03-02 | 2016-07-27 | 天津大学 | Method for preparing high-magnetism ferroferric oxide powder from steel pickling waste liquid |
| CN108238645A (en) * | 2016-12-26 | 2018-07-03 | 惠州市华阳光学技术有限公司 | A kind of preparation method of paramagnetic nanoparticles particle |
| CN107200362A (en) * | 2017-06-26 | 2017-09-26 | 杭州明兴化工有限公司 | A kind of method that pure oxygen oxidizing process produces iron oxide black |
| CN110669565A (en) * | 2019-09-10 | 2020-01-10 | 浙江中博润滑油有限公司 | Preparation method of nano modified transformer oil with high breakdown voltage |
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