Comparison of flotation performances of intruded and conventional coals in the absence of collectors

• Intruded coal surface has more pores, holes and cracks than conventional coal.
• Surface roughness of intruded coal is much higher than that of conventional coal.
• Surface morphology plays a significant role on coal natural floatability.
• Magmatic intrusion has a negative effect on coal natural floatability.
• Flotation performance of conventional coal was better than that of intruded coal.

Magmatic intrusion creates many intruded coals whose properties are different from the conventional coals. It is well known that the surface hydrophobicity and wettability of coal surface are the primarily factors determining the flotation behavior of fine coal particles in coal preparation industry. This paper was to investigate the difference in the flotation behavior between intruded and conventional coals from Yongcheng Coalfield. Brunauer–Emmett–Teller (BET), scanning electron microscopy (SEM), and Fourier transform infrared spectroscopy (FTIR) were used to indicate the surface properties of intruded and conventional coals. The results showed that magmatic intrusion not only changed the functional groups on coal surface but also changed the pore structure of coal particles. The flotation performance of conventional coal was better than that of intruded coal in the absence of collectors. Magmatic intrusion has a negative effect on the natural floatability of coal particles. The natural floatability of coal particle is not only determined by the types of functional groups on coal surface but also affected by the surface morphology of coal particles.