FE3O-4-FORMATION BY THE FERRITE PROCESS - OXIDATION OF THE REACTIVE FE(OH)2 SUSPENSION INDUCED BY SUCROSE

A mechanism of the formation of small particles of iron oxide in the wastewater treatment system 'Ferrite Process' is described. Small particles consisting of the Fe3O4-γ-Fe2O3 solid solution having slightly higher content of γ-Fe2O3 were obtained by the aerial oxidation of Fe(OH)2 suspension in the presence of a weak dispersing reagent, sucrose, at pH 9.0. The increase of γ-Fe2O3 content is caused by a further oxidation of the Fe3O4 particles in the course of the reaction. The further oxidation was accelerated below 1000 Å of the particle size. When SO2-4 ion coexisted with sucrose in the reaction medium, the further oxidation was reduced and the treatment of the wastewater was improved. At a temperature interval of 40°-65°C, the formation of α-FeOOH was completely inhibited by a small amount of sucrose and only Fe3O4 was obtained. © 1979.