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Date of Award
2026
Document Type
Campus Access Master's Report
Degree Name
Master of Science in Chemical Engineering (MS)
Administrative Home Department
Department of Chemical Engineering
Advisor 1
Lei Pan
Committee Member 1
Michael Mullins
Committee Member 2
Kaiwu Huang
Abstract
This research investigates the effects of three distinct gangue minerals—olivine, dunite (serpentine-rich), and gabbro—on the flotation behavior of pyrrhotite through integrated laboratory flotation trials and multi-scale analytical techniques. Flotation experiments revealed that olivine and dunite significantly reduced pyrrhotite recovery, while gabbro exhibited negligible impact on flotation performance. Scanning electron microscopy analysis demonstrated that heterocoagulation between fine olivine and dunite particles and pyrrhotite surfaces is a primary mechanism responsible for reduced recovery, with serpentine-rich dunite displaying more pronounced slime-coating phenomena than olivine or gabbro. Derjaguin-Landau-Verwey-Overbeek (DLVO) analysis confirmed that electrostatic attractions promote aggregate formation, which adversely affects collector adsorption, interferes with particle-bubble attachment, and reduces flotation selectivity. Complementary synchronized tri-wavelength reflection interferometry microscopy (STRIM) studies examined thin liquid film stability between an air bubble and hydrophobic pyrrhotite surface in the presence of each gangue mineral. Result indicates that dunite exhibits the most significant film-stabilizing effects, followed by olivine and gabbro. Film stabilization occurs through adsorption of hydrophilic gangue particles at the air-water interface, creating a physical barrier that impedes film drainage and bubble attachment. The pronounced effect of dunite correlates with its severe slime-coating potential observed in flotation trials. These findings demonstrate that gangue mineralogy critically determines the extent of interference in pyrrhotite flotation, with serpentine-rich minerals posing the greatest challenge through combined heterocoagulation and thin film stabilization mechanisms. The results highlight the need for holistic flotation strategies that specifically address these adverse effects through appropriate dispersant and depressant chemistries tailored to the dominant gangue mineralogy.
Recommended Citation
Agbelusi, Oloruntoba S., "ROLE OF DIFFERENT GANGUE MINERALS ON PYRRHOTITE FLOTATION", Campus Access Master's Report, Michigan Technological University, 2026.