CN102674470B - Method for purifying ferric oxide red by wet method - Google Patents
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Abstract
The invention aims to provide a method for purifying ferric oxide red by a wet method. The method comprises the process route of water-washing, dehydrating and drying and is characterized in that an additive with the ammonia content of 0.05 to 35 percent is added in the water-washing process; impurities are separated by a centrifugal dehydrator during dehydration; preferably, the additive can be ammonia, ammonia water, ammonium carbonate or ammonium hydrogen carbonate with the ammonia content of 0.05 to 35 percent; and the drying method is rotary kiln drying or pulping-centrifugal spraying drying. High-quality ferric oxide powder is obtained by purifying the ferric oxide powder and can serve as a raw material of a high-end product with high magnetic conductivity.
Description
Technical field
The present invention relates to a kind of red iron oxide method of purification, a kind of iron oxide powder solid purifying process utilizing wet processing is provided especially.
Background technology
1, the performance requriements of Mn-Zn ferrite ferric oxide
From the nineties in last century, the world transfers to China in the soft magnetic ferrite production center gradually.According to statistics, national soft magnetic ferrite output in 2000 about 60,000 tons.
Domestic soft magnetic ferrite occupies significant proportion in global low-and-medium-grade products, but the market share in expensive goods is far below day, Ou Deng developed country.Wherein, the restriction of starting material to Chinese soft magnetic ferrite quality is apparent.In Mn-Zn ferrite raw material, the weight percent of ferric oxide is about 70%, so will manufacture high-grade Mn-Zn ferrite, raw iron oxide material must meet corresponding performance requriements.
2, the production technique of ferric oxide
In modern Rolling production, generally use hydrochloric acid to carry out pickling to hot-rolled steel sheet, cool after removing zone of oxidation, spent pickle liquor main component is FeC1 again
2, generate HC1 gas by thermal degradation, water-soluble regeneration HCl recovery uses, and obtains byproduct ferric oxide simultaneously.Ruthner method is the acid recovery process of modern Rolling production first-selection, and its main flow is as follows: acid fluid dissolves waste steel plate, ammonification water extraction high acid solution pH value, and ventilation oxidation produces Fe (OH)
3precipitation, will precipitate condensation product filtering, and the high purity acid solution of gained generates ferric oxide through spray roasting again.The impurity introduced in the production process of ferric oxide mainly contains Al, Cr, Na, P, Si, S, C1 etc.Such as the pickling of autobody sheet of some exotic materials also can introduce B.In order to obtain high-quality high purity ferric oxide, purification process must be carried out to spent pickle liquor and ferric oxide respectively before and after roasting.
3, the performance of ferric oxide is on the impact of manganese-zinc ferrite powder technique and performance
The chemical property of 3.1 ferric oxide
The purity of ferric oxide is the primary factor affecting Mn-Zn ferrite performance, and the impurity in ferric oxide is the abnormal growth affecting crystal grain on the ferritic main manifestations that affects, and causes character defect, thus affects ferritic microtexture and intrinsic characteristic.Wherein, Si and Cl, S content are quite crucial.Add a small amount of Si during pulverizing to be of great benefit to raising Mn-Zn ferrite performance, but Si intrinsic in ferric oxide but has a strong impact on ferrite performance.The acid group elements such as C1, S at high temperature can volatilize, and easy etching apparatus and contaminate environment, serious restriction Mn-Zn ferrite production technique, and performance is had a negative impact.Table l lists the physical and chemical index of domestic and international part quality oxide iron.
The physicals of 3.2 ferric oxide
In actual ferrite production, the starting material that chemical composition is good, sometimes may not necessarily obtain performance and the good ferrite of microtexture, its reason is exactly the impact of physicals.The physicals of the ferric oxide listed by table 1 comprises median size APS, specific surface area SSA and loose density BD.
Because in Mn-Zn ferrite formula, ferric oxide accounts for about 70%, therefore the APS value of its APS value on ferrite powder has great impact.In general, ferric oxide APS value is little, and the APS value of ferrite powder is also little, is conducive to the speed accelerating chemical reaction.But consider the meticulous situation being unfavorable for the compacting of rear road and sintering easy crystallization of powder particles, APS value is unsuitable too small.Obviously, when ferric oxide APS value is excessive, when pre-burning, because particle diameter is comparatively large, only can carries out the diffusion reaction of Spinel, grain growth process can't be carried out further.Intensity of activation required when this must cause sintering improves, and is unfavorable for solid state reaction.
Secondly, in general, croci is thin, and namely specific surface area SSA value is large, and reactive behavior is good, under certain processing condition, easily obtains fine iron oxysome.But meticulous powder is easily reunited, bring difficulty to batch mixing homogeneity.And fine powder very easily causes from sintering in sintering process, forms large single component granule, causes ferrite performance to worsen.Nano raw material just had a strong impact on its application in Mn-Zn soft magnetic ferrite industry from sintering.For spheroidal particle, SSA value is large, then APS value is little.But for irregularly shaped particles, not necessarily so.
Loose density BD is a comprehensive parameters.Generally, APS value is little, and SSA value is large, then BD is little.Because intergranular friction adds.Meanwhile, BD also reflects the shape of particle, and particle shape is more irregular, and sphericity is lower, then BD is less.Research shows, spheroidal particle has better activity than rod particle.
The acquisition of steel mill's solid oxidation iron powder mainly processes spent pickle liquor, generate through spray roasting, current domestic this employing of the present RUTHNER sinter process, for obtaining purer high-quality brown iron oxide, spent pickle liquor carries out fluid purification (desilication process) before carrying out spray roasting.Along with lower end product iron oxysome improving constantly the requirement of brown iron oxide, make it show out following two problems especially, 1, chemical index CL(chloride ion content) do not reach the requirement of ultra high purity nitric oxide iron powder, and fluctuation is comparatively large, and it is often referred to and is marked between 0.1 ~ 0.3%; Physical index BET(physicals) on the low side, generally between 2.0 ~ 3.7/g, the requirement of producing high magnetic permeability ferric oxide (downstream high-end product) can not be reached, and consistence is poor.
Summary of the invention
The object of this invention is to provide a kind of red iron oxide wet-process purification method, obtaining the brown iron oxide of high-quality by purifying to brown iron oxide, can be used as the raw material of high-end product high magnetic permeability.Technical problem solved by the invention is: the content reducing chlorion in brown iron oxide, improves brown iron oxide physical index and improves consistence.
The invention provides a kind of red iron oxide wet-process purification method, operational path is: washing, dehydration, drying, is characterized in that: in water washing process, add the additive that ammonia content is 0.05-35 ﹪, adopts centrifuge to carry out separating impurity during dehydration.Wherein additive is preferably ammonia, ammoniacal liquor, carbonic acid ammonia or the ammonium hydrogencarbonate that ammonia content is 0.05-35 ﹪.Drying means can be rotary kiln drying or slurrying-centrifugal spray drying.
Red iron oxide wet-process purification method provided by the invention, it is characterized in that: the working parameter scope of described centrifuge: rotary drum maximum speed 0-4500 rev/min, conventional working speed 150-4500 rev/min, best result is from factor 2560G, suspension processing power 1-30 cube m/h, maximum deslagging ability 0.1-1500 kg/hour.Water extracter is preferably CF-1500I centrifuge.
Red iron oxide wet-process purification method provided by the invention, it is characterized in that: described water washing process is: brown iron oxide is sent into and dissolves in axe, brown iron oxide dissolves by the ratio being 1:1 ~ 10 in the weight ratio of brown iron oxide and washing water, then adds the additive that weight percent is 0.1% ~ 30%; Slip being remained on temperature is 0-80 DEG C, and rotating speed is stir under 5-150 rev/min of condition, stirs 10-120 minute; Wherein washing water are de-salted water or pure water.
Red iron oxide wet-process purification method provided by the invention, is characterized in that: the concrete technology step of described purification is:
Step a: brown iron oxide is sent into and dissolves in axe, brown iron oxide dissolves by the ratio being 1:1 ~ 10 in the weight ratio of brown iron oxide and washing water, then adds the additive that weight percent is 0.1% ~ 30%; Slip being remained on temperature is 0-80 DEG C, and rotating speed is stir under 5-150 rev/min of condition, stirs 10-120 minute; Wherein washing water are de-salted water or pure water;
Step b: grind slip again, makes Solids Particle Diameter be 0.5-1.0 micron, after grinding, slip is delivered to separating impurity in water extracter, by its solid-liquid separation;
Step c: the solid separated is sent in dissolution kettle, repeats step a, then slip is delivered to separating impurity in water extracter, by its solid-liquid separation; Or directly carry out steps d (namely carrying out the washing of to twice according to brown iron oxide containing water solubles content);
Steps d: the solid aqueous amount separated is 10%-55%, is sent in moisture eliminator and carries out drying treatment.
Red iron oxide wet-process purification method provided by the invention, is characterized in that: in step b, c, slip is sent into water extracter separating impurity, by its solid-liquid separation, controls to consider rear water content and is less than 30%.
Red iron oxide wet-process purification method provided by the invention, is characterized in that: when steps d carries out drying treatment, and after making its brown iron oxide drying, water content is less than 0.3%.
The present invention uses de-salted water or pure water in washing iron oxide red process, de-salted water or pure water are generally acid, pH value is between 4-7, after iron oxide red is dissolved in de-salted water or pure water, mixture is aobvious acid, and ferric oxide, when pH value is less than 3, does not form precipitation, must between 3-13 in order to make ferric oxide form precipitation pH value, so we used additive.This additive can make the mixture PH of deionized water and iron oxide red remain between 3-13, and does not affect the quality of iron oxide red.
We have studied the impact of ferric oxide physicochemical property on ferrite manufacturing process and product performance in conjunction with production practice, and sum up Mn-Zn ferrite ferric oxide and should possess physicochemical property listed in table 2:
The physical and chemical index requirement of table 2 Mn-Zn ferrite ferric oxide
| High purity | Moderate purity | Low-purity | |
| Fe 2O 3/wt% | ≥99.4 | ≥99.2 | ≥98.5 |
| SiO 2/10 -6 | 80~150 | 150~350 | 300~500 |
| CaO/10 -6 | ≤200 | ≤400 | ≤500 |
| Al 2O 3/10 -6 | ≤200 | ≤400 | ≤600 |
| Oxide compound/10 -6 | ≤1000 | ≤1300 | ≤1500 |
| Sulfide/10 -6 | ≤300 | ≤600 | ≤700 |
| APS/μm | 0.6~0.8 | 0.7~0.9 | 0.7~0.9 |
| SSA/m 2·g -1 | 5 | 5 | 4~6 |
| BD/g·cm -3 | 0.45~0.6 | 0.4~0.45 | 0.4~0.6 |
Adopt technical process of the present invention to purify to solid oxidation iron powder, its chemical property index of ferric oxide that purification obtains and physical performance index are all improved, and make the quality of brown iron oxide can meet high-end ferritic ingredient requirement: Cl
-be less than or equal to 0.6%, and make SO
4 2-, P
2o
5, K
2the decline in various degree of the water-soluble micro impurity element such as O, PbO; BET can be increased to 4.0 ~ 5.5m2/g, and consistence significantly improves; Brown iron oxide after solid purification processes can as the raw material of high magnetic permeability ferric oxide.
Accompanying drawing explanation
Fig. 1 CF-1500I centrifuge working mechanism figure.
Embodiment
Embodiment 1
Step a: by the cold-rolling pickling iron oxide red in storage tank, be transported in dissolution kettle via measuring belt scale, the ratio being 1:5 according to cold-rolling pickling iron oxide red and deionized water is dissolved, adding ammonia content is that the ammoniacal liquor of 20% is as additive, then slip being remained on temperature is 30 DEG C, rotating speed is 50 revs/min and stirs, and stirs 20 minutes;
Step b: with ball mill, slip is ground again, Solids Particle Diameter is kept to be 0.5-1.0 micron, through slip being delivered to separating impurity in CF-1500I centrifuge (as shown in Figure 1) by hose pump after grinding, by its solid-liquid separation, controlling to consider rear water content and being less than 30%;
Step c: the liquid separated sends into tank, discharges after treatment.The solid separated is sent in dissolution kettle, then carries out step a, via hose pump, slip is delivered to separating impurity in CF-1500I centrifuge afterwards, by its solid-liquid separation, controls to consider rear water content and is less than 30%;
Steps d: the liquid separated is for once washing.The solid aqueous amount separated is 10%-55%, is sent in moisture eliminator and carries out drying treatment, and after making its brown iron oxide drying, water content is less than 0.3%, and then packaging is outer sells.
Products obtained therefrom foreign matter content is few, and its physicochemical property test result is in table 3.
Embodiment 2
Step a: by the cold-rolling pickling iron oxide red in storage tank, via metering screw Belt Conveying in dissolution kettle, the ratio being 1:2 according to cold-rolling pickling iron oxide red and deionized water is dissolved, adding ammonia content is that the carbonic acid ammonia of 10% is as additive, then slip being remained on temperature is 50 DEG C, rotating speed is 20 revs/min and stirs, and stirs 80 minutes;
Step b: grind slip with ball mill again, keeps Solids Particle Diameter to be 0.5-1.0 micron, through slip being delivered to separating impurity in CF-1500I centrifuge by hose pump after grinding, by its solid-liquid separation, controlling to consider rear water content and being less than 30%;
Step c: the liquid separated sends into tank, discharges after treatment.The solid separated is sent in dissolution kettle, then carries out step a, via hose pump, slip is delivered to separating impurity in CF-1500I centrifuge afterwards, by its solid-liquid separation, controls to consider rear water content and is less than 30%;
Steps d: the liquid separated is for once washing.The solid aqueous amount separated is 10%-55%, is sent in moisture eliminator and carries out drying treatment, and after making its brown iron oxide drying, water content is less than 0.3%, and then packaging is outer sells.
Products obtained therefrom foreign matter content is few, and its physicochemical property test result is in table 3.
Embodiment 3
Step a: by the cold-rolling pickling iron oxide red in storage tank, be transported in dissolution kettle via measuring belt scale, the ratio being 1:9 according to cold-rolling pickling iron oxide red and deionized water is dissolved, adding ammonia content is that the ammonium hydrogencarbonate of 5% is as additive, then slip being remained on temperature is 20 DEG C, rotating speed is 100 revs/min and stirs, and stirs 20 minutes;
Step b: grind slip with sand mill again, keeps Solids Particle Diameter to be 0.5-1.0 micron, through slip being delivered to separating impurity in CF-1500I centrifuge by hose pump after grinding, by its solid-liquid separation, controlling to consider rear water content and being less than 30%;
Step c: the liquid separated sends into tank, discharges after treatment.The solid separated is sent in dissolution kettle, then carries out step a, via hose pump, slip is delivered to separating impurity in CF-1500I centrifuge afterwards, by its solid-liquid separation, controls to consider rear water content and is less than 30%;
Steps d: the liquid separated is for once washing.The solid aqueous amount separated is 10%-55%, is sent in moisture eliminator and carries out drying treatment, and after making its brown iron oxide drying, water content is less than 0.3%, and then packaging is outer sells.
Products obtained therefrom foreign matter content is few, and its physicochemical property test result is in table 3.
Comparative example 1
Do not add additive, other step is with embodiment 1, and products obtained therefrom foreign matter content is many, and its physicochemical property test result cannot meet the listed requirement (see table 3) of table 2.
Comparative example 2
Do not add additive, other step is with embodiment 1, and products obtained therefrom foreign matter content is many, and its physicochemical property test result cannot meet the listed requirement (see table 3) of table 2.
The physical and chemical index of table 3 embodiment products obtained therefrom
| Embodiment 1 | Embodiment 2 | Embodiment 3 | Comparative example 1 | Comparative example 2 | |
| Fe 2O 3/wt% | 99.53 | 99.60 | 99.46 | 99.20 | 99.17 |
| SiO 2/10 -6 | 85 | 74 | 79 | 152 | 142 |
| CaO/10 -6 | 58 | 62 | 60 | 215 | 220 |
| Al 2O 3/10 -6 | 98 | 89 | 88 | 205 | 227 |
| Oxide compound/10 -6 | 980 | 990 | 990 | 2150 | 2200 |
| Sulfide/10 -6 | 244 | 220 | 258 | 560 | 630 |
| APS/μm | 2.77 | 0.71 | 0.80 | 0.85 | 0.81 |
| SSA/m 2·g -1 | 4.15 | 4.20 | 4.08 | 2.28 | 2.81 |
| BD/g·cm -3 | 0.55 | 0.54 | 0.57 | 0.62 | 0.50 |
Claims (5)
1. red iron oxide wet-process purification method, operational path is: washing, dehydration, drying, it is characterized in that: in water washing process, add the additive that ammonia content is 0.05-35 ﹪, adopt centrifuge to carry out separating impurity during dehydration, described additive is ammonia, ammoniacal liquor, volatile salt or bicarbonate of ammonia;
Concrete technology step is:
Step a: brown iron oxide is sent in dissolution kettle, brown iron oxide dissolves by the ratio being 1:1 ~ 10 in the weight ratio of brown iron oxide and washing water, then adds additive; Slip being remained on temperature is 0-80 DEG C, and rotating speed is stir under 5-150 rev/min of condition, stirs 10-120 minute; Wherein washing water are de-salted water;
Step b: grind slip again, makes Solids Particle Diameter be 0.5-1.0 micron, after grinding, slip is delivered to separating impurity in water extracter, by its solid-liquid separation;
Step c: the solid separated is sent in dissolution kettle, repeats step a, then slip is delivered to separating impurity in water extracter, by its solid-liquid separation; Or directly carry out steps d;
Steps d: the solid aqueous amount separated is 10%-55%, is sent in moisture eliminator and carries out drying treatment.
2. according to red iron oxide wet-process purification method described in claim 1, it is characterized in that: the working parameter scope of described centrifuge: rotary drum maximum speed 4500 revs/min, conventional working speed 150-4500 rev/min, best result is from factor 2560G, suspension processing power 1-30 cube m/h, maximum deslagging ability 1500 kgs/hour.
3. according to red iron oxide wet-process purification method described in claim 2, it is characterized in that: described centrifuge is CF-1500I centrifuge.
4. according to red iron oxide wet-process purification method described in claim 1, it is characterized in that: in step b, c, slip is sent into water extracter separating impurity, by its solid-liquid separation, after controlling filter, water content is less than 30%.
5. according to red iron oxide wet-process purification method described in claim 1, it is characterized in that: when steps d carries out drying treatment, after making its brown iron oxide drying, water content is less than 0.3%.
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| CN105399143B (en) * | 2015-12-15 | 2018-05-11 | 上海宝钢磁业有限公司 | A kind of LiFePO4 iron oxide red and preparation method and application |
| CN108695512B (en) * | 2018-06-14 | 2021-06-25 | 东北大学秦皇岛分校 | Use of acid-washed iron oxide red as negative electrode material |
| CN114031385B (en) * | 2021-10-22 | 2023-04-04 | 浙江安特磁材股份有限公司 | Method for preparing permanent magnetic ferrite material from high-chlorine iron oxide red |
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| CN101863515A (en) * | 2009-04-20 | 2010-10-20 | 宝山钢铁股份有限公司 | Purification method of dry-type iron oxide powder solid |
| CN101962209A (en) * | 2009-07-24 | 2011-02-02 | 上海宝钢磁业有限公司 | Post treatment technique of iron oxide red for high-performance Mn-Zn soft magnetic ferrite |
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