Fine coal dry beneficiation using autogenous medium in a vibrated fluidized bed

Abstract

Dry beneficiation of fine coal (−6mm) using autogenous medium in a vibrated fluidized bed has been studied. The results show that in the particulate bed of fine coal, most of −1+0.5mm size fractions of coal and a small portion of −0.5mm size fraction of coal having high ash content contribute to the formation of an autogenous medium bed. This provides a favorable fluidization environment for the stratification process of fine coal particles depending on their density difference. The main operational parameters including superficial air velocity, vibration frequency and amplitude, initial bed height and separating time all have significant influences on the stratification performance of the particulate bed of fine coal. The batch separation results of Wuhai fine coal in an autogenous medium vibrated fluidized bed show that the separation efficiency, i.e. the probable error E, is 0.14, indicating that dry beneficiation of fine coal using an autogenous medium vibrated fluidized bed is a promising technique for coal cleaning in dry regions.