Mineralogical and geochemical compositions of the coal in the Guanbanwusu Mine, Inner Mongolia, China: Further evidence for the existence of an Al (Ga and REE) ore deposit in the Jungar Coalfield

It is suggested that, if Ga in ash > 50 μg/g, REY > 800-900 μg/g, SiO2/Al2O3 < 1 (or Al2O3 > 40% in ash), and coal thickness > 5 m, the coal combustion residues would be expected to be suitably enriched in Al2O3 and can be considered for Al2O3, Ga, and REY recovery.