Abstract
To investigate the effect of carbon defects on the hydrophilicity of the whole surface of the coal pyrite, the adsorption of the single H2O molecule at different sites of the coal pyrite surface was studied with the DFT calculation. It was found that, like the ideal pyrite, the single H2O molecule can stably adsorb at the doping-position, the ortho-position and the meta-position of the coal pyrite. The covalent bond and anti-bond were formed between O (water molecule) and Fe (the coal pyrite) through the Fe 3d orbital and O 2p orbital. Meanwhile, the S–H bond was replaced by the C–H bond. But away from the carbon defect centre, the adsorption of the single H2O molecule increased gradually and the Fe–O covalent bond strength between the single H2O molecule and the pyrite strengthened, which eventually became close to that of the undoped coal pyrite surface.
Highlights
Pyrite usually exists in magmatite rocks, contact metasomatic deposits and hydrothermal deposits.Coal pyrite is the pyrite produced in the coal environment and formed with the formation of coal.The floatability of pyrite is usually determined by its own nature, and the same is true for coal pyrite.The nature of coal pyrite is closely related to its lattice defects
Based on the previous research, the adsorption processes of water molecules are simulated at the doping-position, ortho-position and meta-position of coal pyrite surface with the Density Functional Theory (DFT)+U method
With the doped carbon atom as the centre of the coal pyrite, the of coal pyrite means that the adsorption site was farther away from the centre, as shown in means that the water molecule was adsorbed on the iron atom, which was connected to the carbon means that the water molecule was adsorbed on the iron atom, which was connected to the carbon means that the pyrite was ideal, with no carbon atom
Summary
Pyrite usually exists in magmatite rocks, contact metasomatic deposits and hydrothermal deposits. The authors [5,6] found that there existed doped carbon on the coal pyrite surface and only simulated the effect of carbon defects on the doping-position of coal pyrite This finding revealed the mechanism of change in hydrophobicity at the doping-position using. The adsorption process, when the water molecule adsorbs on the other position of the whole one carbon atom-substituted pyrite surface, was not studied to reveal the mechanism of the whole coal pyrite’s hydrophilicity. Based on the previous research, the adsorption processes of water molecules are simulated at the doping-position, ortho-position and meta-position of coal pyrite surface with the DFT+U method. The adsorption configuration, adsorption strength, bonding properties and bond strength, charge transfer and density of states of water molecules adsorbed at different positions on the coal pyrite surface containing carbon defects are compared with respect to adsorption energy, bond population and Mulliken charge population. The mechanism of the overall weakening of the hydrophilicity of coal pyrite under the condition of carbon defects is fully explained at the molecular level
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
