Dry coal beneficiation by the semi-industrial Air Dense Medium Fluidized Bed with binary mixtures of magnetite and fine coal particles. (1st May 2019)

• Record Type: Journal Article
• Authors: Fu, Zhijie; Zhu, Jesse; Barghi, Shahzad; Zhao, Yuemin; Luo, Zhenfu; Duan, Chenlong
• Is Part Of: Fuel. Volume 243(2019)
• Page Start: 509
• Page End: 518
• Publication Date: 2019-05-01
• Subjects: Air Dense Medium Fluidized Bed -- Dry coal beneficiation -- Binary mixtures; Fuel -- Periodicals; Coal -- Periodicals; Coal; Fuel; Periodicals; 662.6
• DOI: 10.1016/j.fuel.2019.01.140
• Languages: English
• ISSNs: 0016-2361

Abstract

Highlights: Four different coals were beneficiated in a semi-industrial ADMFB system. Binary mixtures of magnetite and fine coal were tested as the medium material. Coal separation performance does not appreciably change at lower excess gas velocities. Coal separation efficiency decreases with the decreasing of feed coal size. Coal separation density can be adjusted by changing fine coal content in medium material. Abstract: Air Dense Medium Fluidized Bed (ADMFB) is deemed to be one of the most efficient methods for dry coal beneficiation. In the present work, a semi-industrial ADMFB system in continuous operation was utilized to study the effects of operating gas velocity, feed coal size, and mixture composition of medium particles on the coal beneficiation in industrial practice. Binary mixtures of magnetite and fine coal particles were used as the medium material, and four different feed coal samples with the size ranges of −50 + 25, −25 + 13, −13 − 6, and −6 + 2 mm were tested individually. The experimental results showed that the influence of excess gas velocity on the dry coal separation is relatively small in the lower flow rates. The separation density and probable error increase with the decreasing of feed coal size, regardless of the type of feed coal. The separation density can be continually reduced by further increasing the fraction of fine coal in the medium material, with the compromise of the increased probable error. Moreover, the ash content and calorific value of −50 + 6 mm coarse coal can be effectively upgraded, but the beneficiation of −6 + 2 mm fine coal was less efficient.