Speaker
Dr
Peace Mkhonto
(University of Limpopo)
Description
In this study ab-initio computational and microcalorimetry methods were used to study the interaction of xanthate collectors of different chain lengths on pyrite (100) and (111) surfaces. The (100) surface was found to be more stable than the (111) surface as such more dominant during ore grinding. This is also confirmed by the surface morphologies of pyrite in both approaches. Four collectors were considered, (i.e. SEX, PNPX, PNBX and PAX). The HOMO and LUMO energies computed from DMol3 revealed that the PAX had the strongest ability to donate its electrons, while SEX had the strongest ability to accept electrons. Furthermore, PAX interaction on the surfaces is the most energetically favourable collector. We also observed that the (111) surface has the strongest heat of adsorption, which is attributed to less surface stability than the (100) surface. The calculated Mulliken atomic charges showed that the xanthate collectors behaves as electron donor with the Fe atoms accept charges, forming a back donation covalent bond. The microcalorimetry test showed similar trend as the DFT adsorptions, however the heats of adsorptions were lower than DFT values. The findings depict the behaviour of xanthate of different chain length and reveal that a longer hydrocarbon chain collector may increase the floatability of the pyrite mineral.
Main supervisor (name and email)<br>and his / her institution
Phuti E. Ngoepe
phuti.ngoepe@ul.ac.za
University of Limpopo
Apply to be<br> considered for a student <br> award (Yes / No)?
No
Level for award<br> (Hons, MSc, <br> PhD, N/A)?
N/A
Would you like to <br> submit a short paper <br> for the Conference <br> Proceedings (Yes / No)?
No
Primary author
Dr
Peace Mkhonto
(University of Limpopo)
Co-author
Dr
Belinda McFadzean
(University of Cape Town)
