1.Manufacture process:
a. Milling magnetite and mill scale into a powder comprising particles of specified particle size;
b. Oxidizing the milled product to obtain a powder containing 98.0% or higher Fe.sub.2 O.sub.3 ;
c. Adding thereto iron oxide originated from iron chloride or iron sulfide together with a carbonate of Sr or Ba;
d. Calcining the resulting powder mixture.
e. Second-milling to certain granularity.
2. By different manufacture procedures, there are two kinds of presintered ferrite powder£ş
A. Wet pressing ferrite powder B. Dry pressing ferrite powder
