High gradient magnetic separation of fly ash

Preliminary experiments have been performed on the high gradient magnetic separation (HGMS) of three fly ash samples. The enrichment of trace elements has been studied in order to determine whether retrieval of raw materials and the removal of harmful elements which might otherwise be leached from the disposed fly ash are feasible. Results are analyzed in terms of the capture efficiency, the magnetization and the elemental composition of the magnetically separated fractions. In all samples the retrieval of iron was quite high, and for the Australian fly ash enrichment by at least a factor of 2 was observed for several trace elements. Explanations are offered for the differences in processing characteristics among the various fly ash samples, and suggestions are given for additional testing to confirm these theories.