Optimal Iron Oxides for Obtaining Hexaferrites

Presently, the ferrites industry consumes large amounts of iron osides obtained by spray roasting of steel pickling liquors. The aim of this paper is to propose the synthesis of optimal iron osidcs by oxyprecipitation of steel pickling liquors in order to obtain Bahexafenite wit11 high magnetic properties using the ceramic process. As a raw material. i t was used sulphuric liqoors with iron concentration of43 gll. The studied variables for the oxyprecipitation step were tc~nperature. pH, stirring speed. flow of oxidizer to obtain goethite and magnetite. The sa~iiples were characterized by XRD and SEM. These oxides were wet milled with barium carbonate and the mixture was calcined i n order to obtain Ba-hexafet~itc. A VSM was used for determine the magnetic properties and the morphology was studied by XRD and SEM. With these resillts five iron oxides were selected and the conditions of the ceramic process (calcination temperature and time) for obtaining hexaferrite were optimized versus H,.