Molecular Dynamics Simulation Study of Bubble Attachment at the Coal Surface with Varying Coalification Degrees

Area of Science:

• Materials Science
• Surface Chemistry
• Computational Chemistry

Background:

• Understanding bubble attachment dynamics on coal surfaces is vital for effective flotation processes.
• Molecular dynamics simulations (MDS) offer a powerful tool to investigate these phenomena at the molecular level, yet have been rarely applied to coal surfaces.

Purpose of the Study:

• To investigate the dynamics of bubble attachment and wetting film rupture on different coal surfaces using MDS.
• To compare bubble attachment behavior across low-rank coal (LRC), bituminous coal (BC), and anthracite coal (AC) with varying hydrophobicity.

Main Methods:

• Molecular dynamics simulations (MDS) were employed to model bubble attachment.
• Analysis included tracking wetting film thinning, rupture, hydrogen bond dynamics, and radial distribution functions (RDFs).

Main Results:

• Bubble attachment rates correlate positively with surface hydrophobicity; faster attachment observed on more hydrophobic surfaces.
• Hydrogen bond numbers within the wetting film decrease during bubble attachment, with distinct patterns for LRC and BC.
• Radial distribution functions (RDFs) of hydrogen bonds show decreased peak intensity upon bubble attachment, indicating structural changes.

Conclusions:

• The study elucidates the molecular-level mechanisms governing bubble attachment and film rupture on diverse coal types.
• Findings provide valuable insights for optimizing coal flotation technologies through tailored surface interactions.