High Characteristic Sr-Ferrite Magnetic Powders Made by New Direct-Spray Roasting

We have studied the process of new direct-spray roasting; SrCO3 powders were directly added into the 12FeCl2 x 4H2O solution first, and then α-Fe2O3 powders with the particle size of 210-620 nm was made after spray roasting in the low temperature of 400-700 degrees C. The direct-spray roasting enables us to get the uniform mixing of α-Fe2O3 and SrCO3 powders, and to lower the calcination temperature of Sr-ferrite, compared to that of the conventional dry method. Also, the magnetic properties of the powders made by direct-spray roasting are very higher than that made by the dry method. We suggest that the Sr-ferrite powders by the direct-spray roasting act as useful high-Br magnetic powders for high characteristic resin-bonded magnet.