Aimants Ugimag Sa

Jean-Marie Boeuf

Henri Lemaire

Pierre Gerest

The invention relates to a process for preparing ferrite powders of Ba, Sr, and/or Pb intended to be incorporated in an elastomeric, thermoplastic, or thermosettable binder for manufacturing flexible or rigid permanent magnets. The process comprises the preparation of a mixture of iron oxides and carbonates of Ba, Sr and/or Pb, adding to said mixture one or more alkaline earth halides in a total proportion of 0.5 to 15% of the total weight of the mixture, and one or more oxygenated boron compounds, more particularly, alkaline and/or alkaline earth borates, in a proportion of 0.2 to 7%, and calcining said mixture between 850.degree. and 1100.degree. C. for at least 15 minutes.

Process of preparing ferrite powders

The invention relates to a process for preparing ferrite powders of Ba, Sr, and/or Pb intended to be incorporated in an elastomeric, thermoplastic, or thermosettable binder for manufacturing flexible or rigid permanent magnets. The process consists of starting out with a mixture of.alpha. Fe.sub.2 O.sub.3 iron oxides and carbonates of Ba, Sr and/or Pb, adding to said mixture one or more alkaline and/or alkaline earth halides in a total proportion of 0.5 to 15% of the total weight of the mixture, and one or more oxygenated boron compounds, more particularly, alkaline and/or alkaline earth borates, in a proportion of 0.2 to 7%, and calcining said mixture between 850.degree. and 1100.degree. C. for at least 15 minutes.

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Grenoble, France

Jean-Marie Boeuf