Abstract
Fe2+ and Mn3+ in Mn-Zn ferrite can be determined by a pair of potentiometric titrations with potassium permanganate after samples are dissolved in strong phosphoric acid (SPA) by the following two methods. Method A: For the determination of Fe2+, a sample is dissolved in SPA containing a large amount of oxalic acid by heating the mixture under the controlled conditions. Method B: For the determination of the difference in the amounts of Fe2+ and Mn3+, a sample is dissolved in SPA in the absence of oxalic acid. Since a small amount of Fe2+ in a sample is oxidized in the course of the dissolution, corrections must be added to the titres of potassium permanganate. Two kinds of ferrite were analyzed by the method presented here. The excess or shortage of oxygen in the samples was calculated from the values obtained, and the compositions of the samples were determined.
