A Morphological Analysis of Magnetic Concentrates in Fly Ash

Abstract

Morphological analysis of magnetic concentrates isolated from fly ash of different fields of ESPs has been carried out using a scanning electron microscopy. It is observed that except the samples collected from fields 1 and 2, other samples (field 3–7) contained magnetic concentrates that are spherical in nature. The fineness of the magnetic concentrates is dependent upon the fields from which the fly ash samples have been collected. In general, the magnetic concentrates become finer in size in samples collected from fields 3–7. Diverse morphological classes of ferrospheres have been observed among magnetic concentrates that include dendritic, granular, smooth, porous, and ferroplerospheres. Such an observation gives valuable information about the cooling history of Fe-bearing melt formed during the combustion of coal. Comparison of X-ray diffractograms and energy dispersive X-ray analysis of an authentic sample of magnetite and that of magnetic concentrate points towards potential utilization of the magnetic concentrates in a coal preparation plant.

Keywords:

• ferrospheres
• magnetic concentrates
• magnetite
• morphological analysis
• scanning electron microscopy-energy dispersive X-ray