Flotation behavior of hard-to-separate and high-ash fine coal
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School of Chemical Engineering and Technology, China University of Mining and Technology
2
China University of Mining and Technology
Publication date: 2016-06-01
Corresponding author
Xiahui Gui
China University of Mining and Technology, No.1, Daxue Road, Nanhu Campus, China University of Mining and Technology, Xuzhou, Jiangsu Province, 221116 Xuzhou, China
Physicochem. Probl. Miner. Process. 2016;52(2):703-717
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ABSTRACT
The flotation behavior of hard-to-separate and high-ash fine coal was investigated using conventional flotation with constant power input. A new flotation process, based on energy input and distribution, was designed to lower the ash content of concentrate. The results obtained using Fourier transform infrared (FTIR) analysis show that the coal samples have good floatability because of many hydrophobic and few hydrophilic functional groups. Under a constant power input, a large number of ash-forming materials floated into a froth product at the start of flotation. Based on the Fuerstenau upgrading curves, it was determined that the 0.25-0.074 mm size fraction range showed the worst selectivity when compared with 0.50-0.25 mm and -0.074 mm size fractions. The desired concentrate with an ash content of 13.98%, 27.59% of ash recovery, and 80.01% combustible matter recovery could be obtained by transferring the excess energy of the flotation-conditioning stage to the pre-conditioning stage and increasing the power input step-by-step in the flotation-conditioning stage at equal total energy consumption.