The Deashing of High-ash Coking Coal Fines by Flotation

Abstract

Coking coal is usually used to produce coke and then coke is applied in the minerals metallurgy. Worldwide, coking coal is relatively exiguous compared with other rank coals, i.e., lignite and anthracite. The high-ash coking coal fines have about 64% ash content in this article. Without the upgrading process, the high-ash coking coal fines can only be used as fuels. It is a waste of the coking coal resource. In this investigation, an attempt was made to float some clean coals from high-ash coking coal fines. Fourier transform infrared was used to indicate the chemical properties of high-ash coking coal fines. Fourier transform infrared results show that the primary mineral is kaolin in the high-ash coking coal fines. Contact angle measurement was also used to indicate the contact angles of coking coal fines at different gravity ranges and it shows that the contact angle decreases with the increase of gravity range. In this article, some clean coals with ash content of 13.48% could be obtained from high-ash coking coal fines based on natural hydrophobicity and low impeller speed.

Keywords:

• coking coal
• contact angle
• flotation
• Fourier transform infrared
• impeller speed
• natural hydrophobicity

Additional information

Funding

This work was supported by the Fundamental Research Funds for the Central Universities (2014XT05) and A Priority Academic Program Development of Jiangsu Higher Education Institutions.