JPS6251894B2 - - Google Patents
Info
- Publication number
- JPS6251894B2 JPS6251894B2 JP54096516A JP9651679A JPS6251894B2 JP S6251894 B2 JPS6251894 B2 JP S6251894B2 JP 54096516 A JP54096516 A JP 54096516A JP 9651679 A JP9651679 A JP 9651679A JP S6251894 B2 JPS6251894 B2 JP S6251894B2
- Authority
- JP
- Japan
- Prior art keywords
- iron oxyhydroxide
- reaction
- ferrous
- seed crystals
- 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.)
- Expired
Links
- 239000002245 particle Substances 0.000 claims description 40
- JZQOJFLIJNRDHK-CMDGGOBGSA-N alpha-irone Chemical compound CC1CC=C(C)C(\C=C\C(C)=O)C1(C)C JZQOJFLIJNRDHK-CMDGGOBGSA-N 0.000 claims description 36
- 229910000859 α-Fe Inorganic materials 0.000 claims description 36
- 238000006243 chemical reaction Methods 0.000 claims description 25
- 238000004519 manufacturing process Methods 0.000 claims description 13
- 239000007864 aqueous solution Substances 0.000 claims description 11
- BAUYGSIQEAFULO-UHFFFAOYSA-L iron(2+) sulfate (anhydrous) Chemical compound [Fe+2].[O-]S([O-])(=O)=O BAUYGSIQEAFULO-UHFFFAOYSA-L 0.000 claims description 11
- 239000003153 chemical reaction reagent Substances 0.000 claims description 9
- NCNCGGDMXMBVIA-UHFFFAOYSA-L iron(ii) hydroxide Chemical compound [OH-].[OH-].[Fe+2] NCNCGGDMXMBVIA-UHFFFAOYSA-L 0.000 claims description 9
- 150000003839 salts Chemical class 0.000 claims description 9
- 229910021506 iron(II) hydroxide Inorganic materials 0.000 claims description 8
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 claims description 6
- 239000007789 gas Substances 0.000 claims description 6
- 239000001301 oxygen Substances 0.000 claims description 6
- 229910052760 oxygen Inorganic materials 0.000 claims description 6
- 229910021519 iron(III) oxide-hydroxide Inorganic materials 0.000 claims description 4
- CUPCBVUMRUSXIU-UHFFFAOYSA-N [Fe].OOO Chemical compound [Fe].OOO CUPCBVUMRUSXIU-UHFFFAOYSA-N 0.000 claims description 3
- 238000010438 heat treatment Methods 0.000 claims description 3
- 239000013078 crystal Substances 0.000 description 49
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 description 24
- 238000000034 method Methods 0.000 description 19
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 10
- 239000000725 suspension Substances 0.000 description 9
- CWYNVVGOOAEACU-UHFFFAOYSA-N Fe2+ Chemical class [Fe+2] CWYNVVGOOAEACU-UHFFFAOYSA-N 0.000 description 8
- 235000011121 sodium hydroxide Nutrition 0.000 description 8
- 239000006247 magnetic powder Substances 0.000 description 7
- KWYUFKZDYYNOTN-UHFFFAOYSA-M Potassium hydroxide Chemical compound [OH-].[K+] KWYUFKZDYYNOTN-UHFFFAOYSA-M 0.000 description 6
- 230000000052 comparative effect Effects 0.000 description 6
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 6
- 238000009826 distribution Methods 0.000 description 5
- 238000000635 electron micrograph Methods 0.000 description 5
- 235000003891 ferrous sulphate Nutrition 0.000 description 5
- 239000011790 ferrous sulphate Substances 0.000 description 5
- 229910000359 iron(II) sulfate Inorganic materials 0.000 description 5
- UQSXHKLRYXJYBZ-UHFFFAOYSA-N Iron oxide Chemical compound [Fe]=O UQSXHKLRYXJYBZ-UHFFFAOYSA-N 0.000 description 4
- 229910052742 iron Inorganic materials 0.000 description 4
- 230000006911 nucleation Effects 0.000 description 4
- 238000010899 nucleation Methods 0.000 description 4
- 239000002994 raw material Substances 0.000 description 4
- 238000007664 blowing Methods 0.000 description 3
- 239000000243 solution Substances 0.000 description 3
- 238000003756 stirring Methods 0.000 description 3
- BVKZGUZCCUSVTD-UHFFFAOYSA-L Carbonate Chemical compound [O-]C([O-])=O BVKZGUZCCUSVTD-UHFFFAOYSA-L 0.000 description 2
- 210000001787 dendrite Anatomy 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 229960002089 ferrous chloride Drugs 0.000 description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-M hydroxide Chemical compound [OH-] XLYOFNOQVPJJNP-UHFFFAOYSA-M 0.000 description 2
- NMCUIPGRVMDVDB-UHFFFAOYSA-L iron dichloride Chemical compound Cl[Fe]Cl NMCUIPGRVMDVDB-UHFFFAOYSA-L 0.000 description 2
- 239000007788 liquid Substances 0.000 description 2
- 239000002184 metal Substances 0.000 description 2
- 229910052751 metal Inorganic materials 0.000 description 2
- 238000002156 mixing Methods 0.000 description 2
- 235000011118 potassium hydroxide Nutrition 0.000 description 2
- ATRRKUHOCOJYRX-UHFFFAOYSA-N Ammonium bicarbonate Chemical compound [NH4+].OC([O-])=O ATRRKUHOCOJYRX-UHFFFAOYSA-N 0.000 description 1
- UIIMBOGNXHQVGW-DEQYMQKBSA-M Sodium bicarbonate-14C Chemical compound [Na+].O[14C]([O-])=O UIIMBOGNXHQVGW-DEQYMQKBSA-M 0.000 description 1
- 230000002378 acidificating effect Effects 0.000 description 1
- 230000002411 adverse Effects 0.000 description 1
- 239000003513 alkali Substances 0.000 description 1
- 239000001099 ammonium carbonate Substances 0.000 description 1
- 235000012501 ammonium carbonate Nutrition 0.000 description 1
- 229910001566 austenite Inorganic materials 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 239000006227 byproduct Substances 0.000 description 1
- 239000003518 caustics Substances 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- 238000001816 cooling Methods 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 230000020169 heat generation Effects 0.000 description 1
- 238000006460 hydrolysis reaction Methods 0.000 description 1
- 150000004679 hydroxides Chemical class 0.000 description 1
- 235000014413 iron hydroxide Nutrition 0.000 description 1
- SZVJSHCCFOBDDC-UHFFFAOYSA-N iron(II,III) oxide Inorganic materials O=[Fe]O[Fe]O[Fe]=O SZVJSHCCFOBDDC-UHFFFAOYSA-N 0.000 description 1
- 239000011859 microparticle Substances 0.000 description 1
- 239000011259 mixed solution Substances 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 230000007935 neutral effect Effects 0.000 description 1
- 230000003472 neutralizing effect Effects 0.000 description 1
- 238000006400 oxidative hydrolysis reaction Methods 0.000 description 1
- 239000003973 paint Substances 0.000 description 1
- 239000000843 powder Substances 0.000 description 1
- 239000002244 precipitate Substances 0.000 description 1
- 230000001376 precipitating effect Effects 0.000 description 1
- 238000002360 preparation method Methods 0.000 description 1
- 239000000047 product Substances 0.000 description 1
- 239000012266 salt solution Substances 0.000 description 1
- 239000002002 slurry Substances 0.000 description 1
- UIIMBOGNXHQVGW-UHFFFAOYSA-N sodium;hydron;carbonate Chemical compound [Na+].OC(O)=O UIIMBOGNXHQVGW-UHFFFAOYSA-N 0.000 description 1
- 239000007858 starting material Substances 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
Description
【発明の詳細な説明】
この発明はα−オキシ水酸化鉄（α−
FeOOH）、さらに詳しくは磁気記録媒体用の酸
化鉄磁性粉末あるいは金属鉄磁性粉末の原料とし
て好適なα−オキシ水酸化鉄の製造方法に関る。DETAILED DESCRIPTION OF THE INVENTION This invention provides α-iron oxyhydroxide (α-
More specifically, the present invention relates to a method for producing α-iron oxyhydroxide, which is suitable as a raw material for iron oxide magnetic powder or metal iron magnetic powder for magnetic recording media.
一般的に、γ−Fe2O3、Fe3O4などの酸化鉄磁
性粉末や金属鉄磁性粉末の粒子構造は出発物質で
あるα−オキシ水酸化鉄に大きく依存するため、
使用するα−オキシ水酸化鉄の性状が極めて重要
である。 In general, the particle structure of iron oxide magnetic powders such as γ-Fe 2 O 3 and Fe 3 O 4 and metal iron magnetic powders largely depends on the starting material α-iron oxyhydroxide.
The properties of the α-iron oxyhydroxide used are extremely important.
従来、α−オキシ水酸化鉄の製造方法として、
第１鉄塩の水溶液に塩基性試剤と酸素含有ガスを
作用させてα−オキシ水酸化鉄を生成させる方法
が汎用されている。上記の方法は、一般的には硫
酸第１鉄や塩化第１鉄などの第１鉄塩の水溶液に
苛性ソーダや炭酸アルカリのような塩基性試剤を
添加して中和反応によつて第１鉄の水酸化物や難
溶性塩を生成させ、ついで空気などの酸素含有ガ
スを吹き込んで酸化加水分解反応によつてα−オ
キシ水酸化鉄とするものであり、最初の中和反応
によつてPHは弱酸性〜中性付近となり、酸化加水
分解反応の進行と共にPHが低下していくのが普通
である。ところが、このような方法で得られたα
−オキシ水酸化鉄は好ましい針状形を呈している
が、これを原料として加熱還元を行なつて金属鉄
磁性粉末を製造した場合、その粒子は原料粒子の
形状が良好な継承されずに針状性がかなり劣つた
ものとなる。 Conventionally, as a method for producing α-iron oxyhydroxide,
A widely used method is to generate α-iron oxyhydroxide by reacting a basic reagent and an oxygen-containing gas with an aqueous solution of a ferrous salt. The above method generally involves adding a basic reagent such as caustic soda or an alkali carbonate to an aqueous solution of ferrous salts such as ferrous sulfate or ferrous chloride, and then neutralizing the ferrous salts. hydroxides and poorly soluble salts are generated, and then an oxygen-containing gas such as air is blown into the iron oxyhydroxide through an oxidative hydrolysis reaction. Usually, the pH becomes weakly acidic to near neutral, and the pH decreases as the oxidation-hydrolysis reaction progresses. However, α obtained by this method
- Iron oxyhydroxide has a preferable acicular shape, but when iron oxyhydroxide is used as a raw material and heat-reduced to produce metallic iron magnetic powder, the particles are acicular because the shape of the raw material particles is not inherited. The condition becomes quite poor.
上記の点を改良する方法として、塩基性試剤の
使用量を多くして、α−オキシ水酸化鉄の生成反
応をアルカリ領域で行なう方法が提案されてい
る。この方法によつて得られたα−オキシ水酸化
鉄を原料として上記と同様に金属鉄磁性粉を製造
した場合には粒子の針状性が非常に良好となる
が、この発明者らの考察によれば、まだ次の諸点
で改良の余地を残している。すなわち、通常の反
応操作によれば双晶あるいは樹枝状晶と呼称され
るような枝分かれした粒子が生成し易いこと、生
成粒子の均一性に難があること、粒度のコントロ
ールが困難であることなどの諸点である。枝分か
れした粒子が多量に存在したり、粒子が不均一で
あれば、これを原料として製造した磁性粉を磁気
記録用に用いたときに磁性塗料調整時の分散性が
悪くなり、磁性層の配向性が表面平滑性を損なつ
て磁気特性に悪影響を及ぼす。また、粒度のコン
トロールが困難であることは、一定した品質のも
のが得られ難いという欠点となる。 As a method for improving the above points, a method has been proposed in which the amount of basic reagent used is increased and the reaction for producing α-iron oxyhydroxide is carried out in an alkaline region. When metallic iron magnetic powder is produced in the same manner as above using α-iron oxyhydroxide obtained by this method as a raw material, the particles have very good acicularity, but the inventors' considerations According to the authors, there is still room for improvement in the following points. In other words, normal reaction operations tend to produce branched particles called twins or dendrites, there are difficulties in the uniformity of the produced particles, and it is difficult to control the particle size. These are the various points. If there are a large number of branched particles or if the particles are non-uniform, when magnetic powder manufactured from these particles is used for magnetic recording, the dispersibility during preparation of magnetic paint will be poor, resulting in problems with the orientation of the magnetic layer. This impairs surface smoothness and adversely affects magnetic properties. Moreover, the difficulty in controlling the particle size is a drawback in that it is difficult to obtain particles of consistent quality.
この発明者らは、α−オキシ水酸化鉄の生成反
応をアルカリ領域で行なう方法について種々検討
を重ねた結果、枝分かれした粒子の生成は結晶核
の生成と結晶成長とが平行して進行するため、既
に形成されて成長過程にある結晶表面に結晶核が
新たに発生あるいは付着して共に成長することに
起因し、粒子の不均一化も結晶核の生成時期の差
によつて起こる（後で生成した粒子ほど小さい）
ことが判つた。さらに結晶核の生成速度と結晶の
成長速度は反応温度によつて異なり、40℃以上の
温度では結晶の成長速度が結晶核の生成速度を上
まわるが、40℃未満の低温下では結晶核の生成速
度がより大となることが判明した。 As a result of various studies on the method of carrying out the production reaction of α-iron oxyhydroxide in an alkaline region, the inventors found that the production of branched particles occurs because the production of crystal nuclei and crystal growth proceed in parallel. This is due to the fact that crystal nuclei are newly generated or attached to the surface of a crystal that has already been formed and is in the process of growth, and grow together. Particle non-uniformity also occurs due to differences in the generation timing of crystal nuclei (later explained) (The smaller the generated particles)
It turned out that. Furthermore, the rate of crystal nucleation and crystal growth differ depending on the reaction temperature; at temperatures above 40°C, the crystal growth rate exceeds the nucleation rate, but at low temperatures below 40°C, the rate of crystal nucleation increases. It was found that the production rate was higher.
この発明は、上記の知見に基づいてなされたも
のであり、第１鉄塩の水溶液に塩基性試剤を作用
させて第１鉄の水酸化物もしくは難溶性塩を析出
させたのち、アルカリ領域下で酸素含有ガスを吹
き込んでα−オキシ水酸化鉄を生成させるに当た
り、あらかじめ別途に上記のα−オキシ水酸化物
の生成反応を結晶核の生成が主となる40℃未満の
低温化で行なつて種晶を製造し、この種晶を反応
系内に加えてα−オキシ水酸化鉄の生成反応を結
晶成長が主となる40〜60℃の温度下で行なつて、
種晶を核としてα−オキシ水酸化鉄を結晶成長さ
せることを特徴とするものである。 This invention was made based on the above findings, and after precipitating ferrous hydroxide or sparingly soluble salt by treating an aqueous solution of ferrous salt with a basic reagent, Before blowing oxygen-containing gas to produce α-iron oxyhydroxide, the above-mentioned α-oxyhydroxide production reaction is separately carried out at a temperature of less than 40°C where crystal nucleus formation is the main activity. Seed crystals are produced, and the seed crystals are added to the reaction system to carry out the production reaction of α-iron oxyhydroxide at a temperature of 40 to 60°C where crystal growth is the main activity.
This method is characterized by crystal growth of α-iron oxyhydroxide using seed crystals as nuclei.
このような方法によれば、あらかじめ低温度で
別途に製造するα−オキシ水酸化鉄の種晶は微細
で均一な粒度を有するものとなるため、これを系
内に加えて40〜60℃の温度下でα−オキシ水酸化
鉄の生成反応を行なえば、均一な粒度の種晶を核
としてほぼ一様に結晶成長がなされ、生成したα
−オキシ水酸化鉄は非常に粒度の揃つた均一なも
のとなる。そして40〜60℃の温度下の反応におい
ては前記のように結晶の成長速度が結晶核の生成
速度を上まわるため、結晶核の新規生成が抑制さ
れて双晶や樹枝状晶と称されるような枝分かれ粒
子の生成が極めて僅かとなる。 According to this method, the α-iron oxyhydroxide seed crystals, which are separately produced in advance at low temperature, have a fine and uniform particle size. If the production reaction of α-iron oxyhydroxide is carried out at high temperature, crystal growth will occur almost uniformly using seed crystals of uniform particle size as nuclei, and the produced α
- Iron oxyhydroxide becomes uniform with very uniform particle size. In reactions at temperatures between 40 and 60 degrees Celsius, the growth rate of crystals exceeds the rate of crystal nucleation as mentioned above, so the generation of new crystal nuclei is suppressed and are called twins or dendrites. The generation of such branched particles becomes extremely small.
さらに、このような方法では、系内に加える種
晶の量を調整することによつて、最終的に得られ
るα−オキシ水酸化鉄の粒度を自由にコントロー
ルすることが可能となる。すなわち、粒度の大き
なα−オキシ水酸化鉄を得る場合には、種晶の添
加量を少なくして、種晶の単位当たりに対して結
晶成長に寄与する成分量が多くなるようにすれば
よく、逆に粒度の小さいものを得るには添加する
種晶の量を多くすればよい。また、この方法は、
α−オキシ水酸化鉄の生成反応自体を２段階とす
る方法、すなわち低温で種晶を生成させたのち、
昇温して種晶を核として結晶成長させる方法に比
較して、粒度コントロールのための反応制御が不
要となる利点を有し、あらかじめ用意した同一の
種晶を使用して、粒度の異なる種々のα−オキシ
水酸化鉄を製造することが可能である。 Furthermore, in such a method, by adjusting the amount of seed crystals added to the system, it is possible to freely control the particle size of the α-iron oxyhydroxide finally obtained. In other words, in order to obtain α-iron oxyhydroxide with a large particle size, it is sufficient to reduce the amount of seed crystals added so that the amount of components contributing to crystal growth per unit of seed crystals increases. Conversely, in order to obtain particles with a small particle size, the amount of seed crystals added can be increased. Also, this method
A method in which the production reaction of α-iron oxyhydroxide itself is carried out in two steps, that is, after producing seed crystals at a low temperature,
Compared to the method of raising the temperature and growing crystals using seed crystals as nuclei, this method has the advantage that reaction control for grain size control is not required. It is possible to produce α-iron oxyhydroxide.
この発明において使用する第１鉄塩としては、
硫酸第１鉄、塩化第１鉄などが挙げられる。 The ferrous salt used in this invention is:
Examples include ferrous sulfate and ferrous chloride.
塩基性試剤としては、第１鉄塩と反応して第１
鉄の水酸化物もしくは難溶性塩を析出するものが
使用でき、普通には苛性ソーダや苛性カリなどの
苛性アルカリが用いられるが、他に炭酸ソーダ、
重炭酸ソーダ、炭酸アンモニウムなどを単独また
は苛性カリと併用して使用してもよい。 As a basic agent, it reacts with ferrous salts to form ferrous salts.
A substance that precipitates iron hydroxide or a hardly soluble salt can be used, and caustic alkalis such as caustic soda and caustic potash are usually used, but other methods include soda carbonate,
Sodium bicarbonate, ammonium carbonate, etc. may be used alone or in combination with caustic potash.
α−オキシ水酸化鉄の生成反応をアルカリ領域
で行なうには、上記のような塩基性試剤を最初か
ら多くするか、または第１鉄塩の水酸化物もしく
は難溶性塩の析出後に塩基性試剤を追加して懸濁
液をアルカリ性としたのち、空気などの酸素含有
ガスを吹き込んで反応させる。この場合、上記の
懸濁液のPHは13以上の強アルカリ性とすることが
望ましい。 In order to carry out the production reaction of α-iron oxyhydroxide in an alkaline region, the amount of the basic reagent described above must be increased from the beginning, or the amount of the basic reagent must be added after the hydroxide of the ferrous salt or the poorly soluble salt has been precipitated. is added to make the suspension alkaline, and then an oxygen-containing gas such as air is blown in to cause a reaction. In this case, it is desirable that the pH of the suspension is strongly alkaline at 13 or higher.
別途に行なう種晶を生成させる反応は、40℃未
満の低温下で行なうが、普通には特別な加熱を加
えず、常温下で行なえばよい。このとき、塩基性
試剤の添加や反応に伴つて過度の発熱が生じる場
合には冷却が必要である。この種晶としては、特
に平均粒度0.02〜0.2μのものが良好である。 The reaction for producing seed crystals, which is carried out separately, is carried out at a low temperature of less than 40°C, but usually it can be carried out at room temperature without applying any special heating. At this time, if excessive heat generation occurs due to addition of the basic reagent or reaction, cooling is required. As this seed crystal, those having an average particle size of 0.02 to 0.2μ are particularly good.
この発明は、上記にて得られた種晶を用い、こ
の種晶を核としてα−オキシ水酸化鉄を結晶成長
させるのであるが、種晶の添加形態は、懸濁液、
スラリー、粉末の何れであつてもよく、簡易には
上記の低温下での反応によつて生じた種晶を懸濁
した反応液をそのまま使用できる。このような種
晶を懸濁した反応液は、液中に未反応物である第
１鉄塩の水酸化物もしくは難溶性塩を多量に含む
ものであつてもよく、これらの未反応物は40〜60
℃の加温下におけるα−オキシ水酸化鉄の結晶成
長に寄与する成分となる。 In this invention, α-iron oxyhydroxide is crystal-grown using the seed crystals obtained as described above and using these seed crystals as nuclei.
It may be either a slurry or a powder, and simply a reaction solution in which seed crystals produced by the above-mentioned reaction at low temperature are suspended can be used as is. The reaction solution in which such seed crystals are suspended may contain a large amount of unreacted ferrous salt hydroxide or poorly soluble salt, and these unreacted products are 40-60
It becomes a component that contributes to crystal growth of α-iron oxyhydroxide under heating at ℃.
種晶は、第１鉄塩の水溶液に塩基性試剤を作用
させたのちの第１鉄の水酸化物もしくは不溶性塩
を含む懸濁液に加えるのが普通であるが、反応前
の第１鉄塩の水溶液（原液）に加えておいても差
しつかえない。また加える種晶の量によつて最終
的に生成するα−オキシ水酸化鉄粒子の大きさが
左右されるが、好ましくは種晶を含む第１鉄の総
量の５〜20％量が種晶となるようにすることが推
奨され、この範囲内で添加量を調整して粒度をコ
ントロールすることが望まれる。 Seed crystals are usually added to a suspension containing ferrous hydroxide or insoluble salts after a basic reagent is applied to an aqueous solution of ferrous salts, but seed crystals are added to a suspension containing ferrous hydroxide or insoluble salts. It can also be added to an aqueous salt solution (undiluted solution). The size of α-iron oxyhydroxide particles that are finally produced depends on the amount of seed crystals added, but preferably 5 to 20% of the total amount of ferrous iron including seed crystals is used as seed crystals. It is recommended that the particle size is controlled by adjusting the amount added within this range.
種晶と第１鉄の水酸化物もしくは不溶性塩を含
む懸濁液にアルカリ領域において40〜60℃の温度
下で空気などの酸素含有ガスを吹き込んで反応さ
せれば、結晶成長が主体的に進行して、枝分かれ
がなく粒度の揃つたα−オキシ水酸化鉄が得られ
る。このとき、液温が60℃を越える高温ではマグ
ネタイト（Fe3O4）が副生する恐れがあるので好
ましくない。 If a suspension containing seed crystals and ferrous hydroxide or insoluble salt is reacted by blowing oxygen-containing gas such as air at a temperature of 40 to 60°C in an alkaline region, crystal growth will take place. As the process progresses, α-iron oxyhydroxide with no branching and uniform particle size is obtained. At this time, if the liquid temperature exceeds 60°C, magnetite (Fe 3 O 4 ) may be produced as a by-product, which is not preferable.
以下、この発明を実施例にて詳細に説明する。 Hereinafter, this invention will be explained in detail with reference to Examples.
実施例
４ｇのFeSO4・7H2Oを25mlの水に溶解させた
硫酸第１鉄水溶液と４ｇのNaOHを25mlの水に溶
解させた苛性ソーダ水溶液とを撹拌混合して水酸
化第１鉄を析出させた。ついで室温（20℃）にお
いて１／minの割合で60分間空気を吹き込んで
α−オキシ水酸化鉄を生成させ、種晶懸濁液を得
た。この種晶は約0.05μの微小粒子であつた。Example: Ferrous hydroxide was precipitated by stirring and mixing a ferrous sulfate aqueous solution in which 4 g of FeSO 4 7H 2 O was dissolved in 25 ml of water and a caustic soda aqueous solution in which 4 g of NaOH was dissolved in 25 ml of water. I let it happen. Then, air was blown at a rate of 1/min for 60 minutes at room temperature (20°C) to generate α-iron oxyhydroxide, thereby obtaining a seed crystal suspension. The seed crystals were microparticles of about 0.05μ.
上記とは別に、16ｇのFeSO4・7H2Oを75mlの
水に溶解させた硫酸第１鉄水溶液と16ｇのNaOH
を75mlの水に溶解させた苛性ソーダ水溶液とを撹
拌混合し、水酸化第一鉄を析出させた。つぎにこ
の懸濁液と上記の種晶懸濁液とを混合した。この
混合液中の第１鉄換算種晶量は第１鉄総量の20％
となつている。この混合液を50℃に加温して１
／minの割合で４時間空気を吹き込んで反応さ
せ、α−オキシ水酸化鉄を得た。第１図に得られ
たα−オキシ水酸化鉄粒子の電子顕微鏡写真を示
す。 Separately from the above, a ferrous sulfate aqueous solution in which 16 g of FeSO 4 7H 2 O was dissolved in 75 ml of water and 16 g of NaOH
and an aqueous solution of caustic soda dissolved in 75 ml of water were mixed with stirring to precipitate ferrous hydroxide. Next, this suspension and the above seed crystal suspension were mixed. The amount of ferrous seed crystals in this mixed solution is 20% of the total amount of ferrous iron.
It is becoming. Heat this mixture to 50℃ and
The reaction was carried out by blowing air at a rate of /min for 4 hours to obtain α-iron oxyhydroxide. FIG. 1 shows an electron micrograph of the α-iron oxyhydroxide particles obtained.
比較例
20ｇのFeSO4・7H2Oを100mlの水に溶解させた
硫酸第１鉄水溶液と20ｇのNaOHを100mlの水に
溶解させた苛性ソーダ水溶液とを撹拌混合して水
酸化第一鉄を析出させたのち、この懸濁液中に液
温50℃にて１／minの割合で空気を吹き込んで
６時間反応を行なつてα−オキシ水酸化鉄を析出
させた。得られた粒子の電子顕微鏡写真を第２図
に示す。Comparative example Ferrous hydroxide was precipitated by stirring and mixing a ferrous sulfate aqueous solution in which 20 g of FeSO 4 7H 2 O was dissolved in 100 ml of water and a caustic soda aqueous solution in which 20 g of NaOH was dissolved in 100 ml of water. After this, air was blown into the suspension at a rate of 1/min at a liquid temperature of 50°C to carry out a reaction for 6 hours to precipitate α-iron oxyhydroxide. An electron micrograph of the obtained particles is shown in FIG.
第３図は上記の実施例および比較例にて得られ
たα−オキシ水酸化鉄粒子の各々の長軸方向の粒
度分布を示し、図中の曲線Ａは実施例の、曲線Ｂ
は比較例の粒度分布を示す。 FIG. 3 shows the particle size distribution in the long axis direction of the α-iron oxyhydroxide particles obtained in the above Examples and Comparative Examples, and the curve A in the figure is the curve B of the example.
shows the particle size distribution of the comparative example.
第１図と第２図の電子顕微鏡写真の比較および
第３図の粒度分布曲線の比較から、低温で反応さ
せて得た種晶を加えるこの発明方法では枝分かれ
が非常に少なく粒度が揃つた均一なα−オキシ水
酸化鉄が得られるのに対し、低温下での反応によ
る種晶を加えない比較例方法では枝分かれした粒
子が多く生成し、かつ粒度の分布巾が大きく均一
性に欠けることがわかる。 A comparison of the electron micrographs in Figures 1 and 2 and a comparison of the particle size distribution curves in Figure 3 shows that the method of this invention, in which seed crystals obtained by reaction at low temperatures are added, has very little branching and is uniform in particle size. In contrast, in the comparative example method in which seed crystals are not added due to the reaction at low temperatures, many branched particles are produced, and the particle size distribution is wide and lacks uniformity. Recognize.
第１図は実施例にて得られた、第２図は比較例
にて得られたそれぞれのα−オキシ水酸化鉄粒子
の形状を示す電子顕微鏡写真図であり、第３図は
実施例および比較例にて得られたα−オキシ水酸
化鉄の長軸方向の粒度分布を示す図である。
FIG. 1 is an electron micrograph showing the shapes of α-iron oxyhydroxide particles obtained in Examples, FIG. 2 is an electron micrograph showing the shapes of α-iron oxyhydroxide particles obtained in Comparative Examples, and FIG. FIG. 3 is a diagram showing the particle size distribution in the long axis direction of α-iron oxyhydroxide obtained in a comparative example.
Claims (1)
第１鉄の水酸化物もしくは不溶性塩を析出させた
のち、アルカリ領域において40〜60℃の加温下で
酸素含有ガスを吹き込んでα−オキシ水酸化鉄を
生成させるに当り、別途に上記のα−オキシ水酸
化鉄の生成反応を40℃未満の低温下で行つて得た
α−オキシ水酸化鉄粒子を前記反応系内に加え、
α−オキシ水酸化鉄の生成反応を行なうことを特
徴とするα−オキシ水酸化鉄の製造方法。1. A basic reagent is applied to an aqueous solution of ferrous salt to precipitate ferrous hydroxide or insoluble salt, and then oxygen-containing gas is blown into the alkaline region under heating at 40 to 60°C to obtain α - In producing iron oxyhydroxide, α-iron oxyhydroxide particles obtained by separately performing the above α-iron oxyhydroxide production reaction at a low temperature of less than 40°C are added to the reaction system. ,
A method for producing α-iron oxyhydroxide, which comprises carrying out a reaction for producing α-iron oxyhydroxide.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP9651679A JPS5622637A (en) | 1979-07-27 | 1979-07-27 | Manufacture of alpha-iron oxyhydroxide |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP9651679A JPS5622637A (en) | 1979-07-27 | 1979-07-27 | Manufacture of alpha-iron oxyhydroxide |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS5622637A JPS5622637A (en) | 1981-03-03 |
| JPS6251894B2 true JPS6251894B2 (en) | 1987-11-02 |
Family
ID=14167297
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP9651679A Granted JPS5622637A (en) | 1979-07-27 | 1979-07-27 | Manufacture of alpha-iron oxyhydroxide |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS5622637A (en) |
Families Citing this family (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5139767A (en) * | 1981-06-22 | 1992-08-18 | Mitsui Toatsu Chemicals, Incorporated | Production method of goethite |
| JPS60137832A (en) * | 1983-12-22 | 1985-07-22 | Toyo Soda Mfg Co Ltd | Production of iron alpha-oxyhydroxide in strip state |
| JPS60141625A (en) * | 1983-12-28 | 1985-07-26 | Toyo Soda Mfg Co Ltd | Preparation of fine particulate alpha-iron oxyhydroxide |
| JPS6158215A (en) * | 1984-08-29 | 1986-03-25 | Hitachi Maxell Ltd | Manufacture of magnetic iron oxide powder |
| JPS6172628A (en) * | 1984-09-18 | 1986-04-14 | Toda Kogyo Corp | Production of goethite particle powder showing strip shape |
| JPS6183631A (en) * | 1984-09-29 | 1986-04-28 | Toda Kogyo Corp | Production of strip type of fine particles of magnetic iron oxide |
| JPS63134523A (en) * | 1986-11-22 | 1988-06-07 | Chisso Corp | Production of needle-like iron alpha-oxyhydroxide particulate powder |
-
1979
- 1979-07-27 JP JP9651679A patent/JPS5622637A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS5622637A (en) | 1981-03-03 |
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