2FeO(OH) + 3Br2 + 10KOH 2K2FeO4 + 6KBr + 6H2O
Iron(III) oxide-hydroxide react with bromine and potassium hydroxide to produce potassium ferrate, potassium bromide and water. Potassium hydroxide - concentrated solution. This reaction takes place at a temperature of 45-55°C.