Method for making m- type hexaferrite powders or wafers
US6761830B1 · kind B1 · utility
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17Claims
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Key dates
| Filing date | Feb 15, 2002 |
| Grant date | Jul 13, 2004 |
| Priority date | — |
| Expiry date | Mar 10, 2022 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC01P2006/42
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
A method for manufacturing type M hexaferrite powders fo the formula AFe12O19 where A is Ba, Sr, Ca, Pb or a mixture thereof. An iron oxide Fe2O3 and a compound A are mixed with a molar ratio n=Fe2O3/AO, formed and calcined, and the agglomerates which result from the calcining are ground to obtain a fine ferrite powder. The mixture is formed with a ratio n ranging between 5.7 and 6.1, and with a predetermined degree of homogeneity, and before or during the grinding process, an agent controlling the microstructure is introduced.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.