PRODUCTION OF BARIUM AND MAGNESIUM FERRITES USING ELECTROCHEMICAL SYNTHESIS OF PRECURSORS

Particles of precursors of barium hexaferrite, as well as magnesium ferrite, were obtained by anodic dissolution of a steel electrode in an aqueous solution containing barium and magnesium nitrates at a concentration of 0.15 mol/ l with the introduction of hydrochloric acid into the solution, followed by hydrolysis of the products of anodic dissolution and high-temperature treatment of the precipitate. Electrolysis with a soluble anode (St.3) was carried out in a coaxial cylindrical cell with a cathode in the form of a rod made of steel X18H10T, the area of which is more than 100 times smaller than the area of the anode, at an anode current density of 3 A/dm2 for two hours and free oxygen access. It has been established that the anode current output exceeds 100%, which is due to the negative differential effect caused by the occurrence of chemical dissolution of the metal along with electrochemical. At the end of the process, the precipitate was kept in a mother liquor for a day, filtered, while the precipitate was repeatedly washed with distilled water to a neutral reaction, and dried at a temperature of 100°C for two days. X-ray phase analysis revealed that when the precipitate is heated to 100°C, separate phases are formed in the form of spinel: magnesium ferrite, and iron (II, III) oxides - magnetite and barium (II). Perhaps this is due to the insufficient heating temperature and the duration of heat treatment for the formation of barium hexaferrite. During high-temperature processing (1100°C), barium hexaferrite is formed, but its quantitative content in the product is less than that of magnesium ferrite.