Magnetite-iron based composite powder, magnetite-iron based powder mixture, method for producing the same, method for remedying polluted soil, water or gases and electromagnetic wave absorber
US6827757B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | May 29, 2002 |
| Grant date | Dec 7, 2004 |
| Priority date | — |
| Expiry date | May 29, 2022 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC01P2006/80
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
A magnetite-iron based composite powder includes magnetite with a ratio of X-ray diffraction intensity to that of &agr;-Fe of about 0.001 to about 50 and has an average primary particle size of about 0.1 to about 10 &mgr;m. The composite powder can highly dehalogenate organic halogen compounds and exhibits satisfactory absorption power of high frequency electromagnetic waves after molding. An ultrafine nonferrous inorganic compound powder may adhere to the surface of the composite powder, or at least the composite powder may adhere to the surfaces of small particles of a nonferrous inorganic compound to thereby yield a composite powder composition. The composite powder can be produced by partial reduction of a material powder containing a hematite based powder or by complete reduction and subsequent partial oxidation of the material powder.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.