Effect of intergrown particle liberation on difficult-to-separate coking coal flotation
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Chinese National Engineering Research Center of Coal Preparation and Purification, Xuzhou 221116, Jiangsu, China
School of Chemical Engineering and Technology, China University of Mining and Technology, Xuzhou 221116, Jiangsu, China
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
Publication date: 2016-01-01
Physicochem. Probl. Miner. Process. 2016;52(1):279–294
Flotation tests with intergrown particle liberation were conducted to explore a separation method of difficult-to-separate coking coal from the Tangshan Kailuan mine in China. The particle size distribution, density and coal petrography were investigated. The difficult-to-separate coking coal sample resulted in intergrown particles, such as non-liberated coal and rocks. Thus, intergrown coal particle liberation and re-separation tests were conducted. The results showed that grinding time had a great effect on the flotation performance. Grinding prompted coal to dissociate and improve the surface hydrophobic properties of minerals. However, heterogeneous fine silt covered the surface of coal particles when coal was ground too long. The inorganic mineral particles were over-ground and reduced the contact angle of coal. The results of coal rock dissociation and laboratory re-separation tests showed that clean coal combustible recovery increased through intergrown particle liberation and re-separation.