engleski

Chemical reduction of hematite with starch

Chemical reduction of hematite with starch in air at elevated temperature was investigated using X-ray powder diffraction, FT-IR and ^57 Moessbauer spectroscopies. On heating the starting mixture for 0.5 and 2 hours at 300 C, magnetite and a small fraction of hematite were identified by XRD. With the heating time prolonged up to 24 hours, magnetite reoxidized and hematite was obtained again. The formation of magnetite was observed even at 580 C. However, the magnetite formed at this temperature was substoichiometric, as shown by XRD and Moessbauer spectroscopy. Characteristic IR bands of oxide phases were monitored by FT-IR spectroscopy. Chemical reduction of hematite with starch into a Fe^o state was not observed in any sample.

chemical reduction; hematite; iron oxides

nije evidentirano