DEASHING COAL BY CRUSHING/WASHING/SEPARATING/FLOTATION

摘要

Disclosed is a process for deashing coal, which comprises the following steps (a) to (e): (a) crushing coal to form crushed coal having a particle size distribution of 0.05 to 15 mm and an average particle size of 0.5 to 2 mm, (b) producing an aqueous slurry comprising the crushed coal, 1 to 4 wt. % of a binder based on the crushed coal, and water, (c) feeding the aqueous slurry of the crushed coal to a cylindrical agglomerator provided with disk impellers in a multistage manner and effecting collision and agglomeration among the crushed coal particles by the rotation of the impellers and effecting tumbling and agglomeration of the agglomerate to produce an aqueous slurry of spherical or spheroidal hard agglomerated coal, (d) separating the aqueous slurry of the agglomerated coal by treating with a solid-liquid separator into first agglomerated coal on the separating medium and an aqueous slurry of second agglomerated coal and ash which have passed through the separation medium, and (e) adding a frother or a frother-based flotation reagent to the aqueous slurry of the second agglomerated coal and the ash and recovering the second agglomerated coal by flotation.