The processes of obtaining iron oxides by combustion from nitrate solutions with a dual fuel consisting of urea and citric acid on a preliminarily prepared FeOx powder have been investigated. The possibility of synthesizing up to 100 g of the target product under laboratory conditions in a relatively small reactor with a volume of 4 dm3 was demonstrated for the first time. The received nanodispersed materials represent a well-crystallized mixture of oxides Fe3O4 and α-Fe2O3. A consistent increase in the weight of the FeOx powder leads to an increase in the mass fraction of the α-Fe2O3 phase to 91% stage at the final stage of synthesis.