Preparation of ferric oxide for ferrites based on goethite synthesis by an ammoniacal method

Conclusions It is shown that goethite (yellow ferrie oxide pigment) synthesis by an ammoniacal method offers a suitable means of obtaining, from technical iron vitriol, high-purity ferric oxide with stable properties fulfilling the requirements for ferrite-grade ferric oxide. The ferric oxide is distinguished by its high reactivity after high-temperature (850–900°C) heat treatment. Its physicochemical properties are close to those of 1360 WF grade ferric oxide manufactured by the Bayer Co. of West Germany 5]. The key process parameters in the production of ferric oxide by this method are: goethite synthesis pH 4.0–4.5, synthesis temperature 70–75°C, amount of seed 8–10% of the goethite content at the end of synthesis, and ferric oxide calcining temperature 850–900°C.Translated from Poroshkovaya Metallurgiya, No.4(160), pp. 82–88, April, 1976.