Speaker
Description
Mooihoekite (Cu₉Fe₉S₁₆) is a copper–iron sulfide with a tetragonal, metal-rich structure derived from chalcopyrite, commonly intergrown with other sulfides such as haycockite and pentlandite in complex ore deposits. Despite its relevance in flotation systems, its flotation behavior remains poorly understood, limiting the optimization of separation processes that rely on mineral-specific surface and electronic properties. To address this, density functional theory with dispersion corrections and a Hubbard U term (DFT-D+U) was used to evaluate surface energies and identify stable crystallographic planes for adsorption studies. The (402) surface was found to be the most stable, exhibiting the lowest positive surface energy, and was selected as a representative model of reactive sites likely encountered under flotation conditions. Adsorption of S-allyl-N-diethyl-dithiocarbamate (ADEDTC) and O-isopropyl-N-diethyl-thionocarbamate (IPDETC) on the (402) surface showed strong chemisorption through coordination between sulfur atoms and surface Fe and Cu sites. ADEDTC displayed more exothermic adsorption energy (–550.02 kJ·mol⁻¹) than IPDETC (–193.11 kJ·mol⁻¹), indicating stronger and more favorable interactions. Bader charge analysis confirmed significant electron transfer from surface Cu and Fe ions to the adsorbates, with greater charge redistribution observed for ADEDTC. These findings provide insight into surface–collector interactions and highlight ADEDTC as a promising collector for improving flotation performance in Mooihoekite-bearing ores.
| Apply for student award at which level: | MSc |
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| Consent on use of personal information: Abstract Submission | Yes, I ACCEPT |