COPRECIPITATION OF MnZn FERRITE
Original Publication Date: 1983-Dec-01
Included in the Prior Art Database: 2005-Feb-08
In the present manufacture of manganese-zinc (MnZn) ferrite it is necessary to ball mill the ferrite before an acceptable product can be obtained. This ball milling can leave an uncontrolled amount of impurities in the ferrite product. This ball milling step can be avoided by closely controlling the pH of the solutions and the temperature of the processing. In the preparation of the ferrite, metal ions are coprecipitated as oxalate powders. A metal ion solution, such as a manganese-zinc sulphate or nitrate solution, is prepared and heated to a temperature of approximately 50ŒC or less. An oxalate solution, such as ammonium oxalate, is separately prepared at a temperature of approximately 70ŒC. The pH of the oxalate solution is adjusted to between 3 and 5 with sulphuric acid.