Recovering clean low-rank coal using shale oil as a flotation collector

ABSTRACT

Shale oil (SO) was adopted as flotation collector to recover clean low-rank coal. Gas chromatography-mass spectrometry, flotation, X-ray photoelectron spectroscopy and contact angle measurements were performed to identify the chemical constituents and flotation performance of SO, and the surface properties of low-rank coal. The results indicated that the long-chain hydrocarbon and high viscosity of SO may lead to the higher combustible matter recovery and lower ash content of clean coal. The adsorption of SO significantly enhanced the carbon-bearing content and decreased the C−O content, which was favorable to enhance the hydrophobicity, and thus improve the flotability of low-rank coal.

KEYWORDS:

• Low-rank coal
• shale oil
• recovery
• flotation
• collector

Acknowledgments

This work was supported by the Fundamental Research Funds for Central Universities [grant number 2017XKZD04].