发明名称 |
Production of nanoscale maghemite powder involves precipitation from solution of ferrous and ferric sulfates in oxygen-free deionized water with sodium hydroxide, washing, acidification, quantitative oxidation and dialysis |
摘要 |
Production of nanoscale maghemite powder comprises: (a) dissolving iron(II) and iron(III) sulfates in oxygen-free deionized water to a total iron concentration of 0.1-1.1 mole/l and Fe<2+>/Fe<3+> molar ratio of about 1:2; (b) adding sodium hydroxide; (c) washing the precipitate; (d) adding acid to pH 0.5-3; (e) quantitative oxidation of Fe<2+> to Fe<3+> with air; and (f) removing salts from the precipitate. Production of nanoscale maghemite powder comprises (a) preparing a solution of iron(II) sulfate, FeSO4, and iron(III) sulfate, Fe2(SO4)3, in deionized water, freed from oxygen, so that the total iron (Fe) concentration is 0.1-1.1 mole/l and the molar ratio of Fe<2+>/Fe<3+> ions is about 1:2; (b) adding sodium hydroxide (NaOH) to a molar ratio of NaOH to total Fe of 2.7-3; (c) washing the resultant precipitate with deionized water; (d) adjusting the pH of the precipitate to 0.5-3 by adding acid; (e) quantitative conversion of the Fe<2+> present to Fe<3+> by oxidation with air at 60-100 deg C; and (f) separating the precipitate, taking it up in water and freeing it from salts by dialysis.
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申请公布号 |
DE19859687(A1) |
申请公布日期 |
2000.06.29 |
申请号 |
DE19981059687 |
申请日期 |
1998.12.23 |
申请人 |
BAYER AG;INSTITUT FUER NEUE MATERIALIEN GEMEINNUETZIGE GMBH |
发明人 |
NONNINGER, RALF;JOST, MARTIN |
分类号 |
C01G49/06;(IPC1-7):C01G49/02 |
主分类号 |
C01G49/06 |
代理机构 |
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地址 |
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