In this study,the physicochemical cleaning of Shendong long flame coal was investigated by flocculation flotation to produce ultra clean coal.Flotation experiments were designed with Box Behnken Design which is a response surface method.The separate action and interaction effects of kerosene dosage(A),secondary octanol dosage(B),and agitation speed(C) on ash content and yield of the concentrate were evaluated in the flotation experiments.The results showed that the significance of influencing factors on ash content followed the order:C>B>A,AB>AC>BC,the significance of influencing factors on yield followed the order:B>A>C,AC>BC>AB.The optimal conditions were kerosene dosage of 1.55mL,secondary octanol dosage of 335μL and agitation speed of 3690r/min with 1.72% ash content and 45.03% yield respectively in the concentrate.
