QUANTIFICATION OF FERRITE SPINEL AND HEMATITE IN FLY ASH MAGNETICALLY ENRICHED FRACTIONS

Iron oxide phases, including ferrimagnetic spinel structure phases, are found in all fly ashes and other coal combustion by-products. Magnetically enriched fractions of several fly ashes were used to investigate Rietveld quantitative X-ray diffraction (RQXRD) of the iron oxide phases in fly ash. A comparison between “magnetite” (ferrite spinel) to hematite ratios obtained by RQXRD with those obtained by isothermal remnant magnetization was made.