Effect of coal particle swarm properties on the fluidization characteristics and coal beneficiation in a dense-phase gas

Zhang, B., Zhou, C., Chen, Z., & Zhao, Y. (2017). Effect of coal particle swarm properties on the fluidization characteristics and coal beneficiation in a dense-phase gas–solid fluidized bed. Particuology, 35, 108-118. https://doi.org/10.1016/j.partic.2017.06.001

Effect of coal particle swarm properties on the fluidization characteristics and coal beneficiation in a dense-phase gas–solid fluidized bed

Bo Zhang ^{a b}, Chenyang Zhou ^a^b, Zengqiang Chen ^{a b}, Yuemin Zhao ^{a b *}

a Key Laboratory of Coal Processing and Efficient Utilization of Ministry of Education, China University of Mining & Technology, Xuzhou 221116, China
b School of Chemical Engineering and Technology, China University of Mining & Technology, Xuzhou 221116, China

10.1016/j.partic.2017.06.001

Volume 35, December 2017, Pages 108-118

Received 19 February 2017, Revised 22 June 2017, Accepted 24 June 2017, Available online 23 August 2017, Version of Record 30 November 2017.

E-mail: ymzhao_paper@126.com; ymzhao@cumt.edu.cn

Highlights

• The thickness of low density layer affected the final settling time of high density particles.

• Coal swarm properties would affect the fluidization characteristic in the fluidized bed.

• The feeding mass fraction of coal should be limited to 10% and 13% respectively.

Abstract

This paper analyzes the influence of different coal mass fraction in an air dense medium fluidized bed (ADMFB). The effect of the low density particles layer on heavy sedimentation increased with increasing material layer thickness. The thickness of the low density particles layer also affected the final settling time of the high density particles. Increasing the thickness of the low density particles layer by Δh provoked an increase in the settling of high density particles that was related to their diameter (Δh/D). The pressure gradient across the bed was lower than that observed for the control experiment, which had only the dense material, owing to a decrease in the pressure gradient in Zones 1 and 5 (at the top and bottom of the bed, respectively). Introducing different coal sizes resulted in different fluidization environments, particle accumulation layers, and changes to the surrounding zone. However, the influence of the coal particles on the local bed characteristics was related to its concentration. The feeding mass fraction of 6–13 mm size and 13–25 mm size coal should be limited to10% and 13%, respectively. The ranges of possible deviation were found to be 0.08–0.15 and 0.07–0.10 for the respective samples.

Graphical abstract

Keywords

Coal separation; Particle size distribution; Fluidized bed; Separation performance

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