Manufacture of acicular ferromagnetic iron particles
    3.
    发明授权
    Manufacture of acicular ferromagnetic iron particles 失效
    针状铁磁铁颗粒的制造

    公开(公告)号:US4178171A

    公开(公告)日:1979-12-11

    申请号:US888508

    申请日:1978-03-20

    摘要: A process for the manufacture of acicular ferromagnetic iron particles by reducing acicular iron(III) oxide hydroxides which consist of pure synthetic lepidocrocite or a mixture of synthetic goethite and at least 70% by weight of synthetic lepidocrocite.The iron(III) oxide hydroxides used carry, on their surface, an alkaline earth metal cation and an anion of a monobasic, dibasic or tribasic aliphatic carboxylic acid of up to 6 carbon atoms or an organic compound containing at least two groups capable of chelating the alkaline earth metal cation, and are produced in such a way that they consist of at least 70 percent by weight of lepidocrocite and have a length-to-width ratio of not less than 15:1.Reduction of such iron(III) oxide hydroxides gives iron particles with pronounced shape anisotropy, which exhibit both good magnetic properties and a narrow field strength distribution.

    摘要翻译: 通过还原针状铁(III)氢氧化物来制造针状铁磁性铁粒子的方法,该针状铁氧化物由纯合成锂铁矿石或合成针铁矿和至少70%重量的合成锂铁矿石混合物组成。 所用的氧化铁(III)氢氧化物在其表面上带有至多6个碳原子的一元,二元或三元脂肪族羧酸的碱土金属阳离子和阴离子,或含至少两个能够螯合的基团的有机化合物 碱土金属阳离子,并且以这样的方式制备,使得它们由至少70重量%的氯铁矿石组成,并且具有不小于15:1的长宽比。 这种氧化还原铁(III)氢氧化物的还原产生具有显着形状各向异性的铁颗粒,其具有良好的磁性能和窄的场强分布。

    Preparation of acicular gamma-iron(III) oxide of high coercive force
    6.
    发明授权
    Preparation of acicular gamma-iron(III) oxide of high coercive force 失效
    制备高矫顽力的针状γ-铁(III)氧化物

    公开(公告)号:US4362708A

    公开(公告)日:1982-12-07

    申请号:US320014

    申请日:1981-11-10

    摘要: A process for the preparation of acicular gamma-iron(III) oxide of high coercive force by reducing acicular iron(III) oxide hydroxide, as it is being passed continuously through a furnace having two or more heating zones at from 190.degree. to 700.degree. C., by means of a gas mixture which is produced by passing a stream of inert gas, heated to above 250.degree. C., through an organic substance also heated to above 250.degree. C. in a vessel, and, on introduction into the furnace, is first brought into contact with the .alpha.-iron(III) oxide formed from the iron(III) oxide hydroxide by elimination of water in the first heating zone of the furnace at from 190.degree. to 250.degree. C., the .alpha.-iron(III) oxide thereby being converted to magnetite which is subsequently oxidized with an oxygen-containing gas at from 150.degree. to 400.degree. C., to give gamma-iron(III) oxide.

    摘要翻译: 一种通过还原针状氧化铁(III)氢氧化物制备高矫顽力的针状γ-铁(III)氧化物的方法,因为它连续通过具有两个或多个加热区的炉子在190℃至700℃ 通过将加热至高于250℃的惰性气体流通过容器中也被加热至高于250℃的有机物质,并通过引入到 炉子首先通过在190℃至250℃的炉的第一加热区中消除水而与由氧化铁(III)氧化物形成的α-铁(III)氧化物接触, 氧化铁(III),从而转化为磁铁矿,随后在150-400℃下用含氧气体氧化,得到氧化三氯化铁(III)。

    Manufacture of acicular cobalt-containing magnetic iron oxide
    8.
    发明授权
    Manufacture of acicular cobalt-containing magnetic iron oxide 失效
    针状钴磁性氧化铁的制造

    公开(公告)号:US4287233A

    公开(公告)日:1981-09-01

    申请号:US116543

    申请日:1980-01-29

    IPC分类号: G11B5/706 C01G49/06

    CPC分类号: G11B5/70657

    摘要: A process for the manufacture of acicular magnetic iron oxide consisting of core of gamma-iron(III) oxide and a ferrite shell which contains, based on the total amount of magnetic material, from 0.2 to 12 per cent by weight of cobalt(II) ions and from 0.1 to 15 per cent by weight of iron(II) ions, wherein a precipitate of cobalt(II) hydroxide and iron (II) hydroxide is applied to acicular gamma-iron(III) oxide particles and the latter are heated at 100.degree.-200.degree. C.

    摘要翻译: 制造由γ-铁(III)氧化物核心和铁氧体壳组成的针状磁性氧化铁的方法,其包含基于磁性材料总量的0.2至12重量%的钴(II) 离子和0.1至15重量%的铁(II)离子,其中将氢氧化钴(II)和氢氧化铁(II)的沉淀物施加到针状γ-铁(III)氧化物颗粒上,并将后者加热至 100℃-200℃