Study on a New Iron Phosphate Crystalline Phase

Abstract An iron phosphate having a new crystalline phase was obtained by a partial reduction of iron(III) orthophosphate with a reducing agent, usually oxalic acid, in the presence of oxygen and a large amount of water vapor at a low temperature of 200 to 250 °C. XRD spectra of the new phase (designated as M-phase) are similar to those of clay minerals. The effects of reaction variables, such as reducing agent, reaction period, starting iron phosphate, temperature, and oxygen feed rate, on the formation of M-phase were studied. Some characterizations of this M-phase were also attempted.