MSE Graduate Seminar: Mitigating the Negative Effect of Anisotropic Clay Particles in Flotation and Dewatering Operations in Mineral Processing Using Biopolymers

Title: Mitigating the Negative Effect of Anisotropic Clay Particles in Flotation and Dewatering Operations in Mineral Processing Using Biopolymers
Presenter: Nahid Molaei (PhD candidate, 2nd seminar)
Supervisor: Prof Erin Bobicki

Abstract:

The depletion of high-grade ore resources and ongoing demand for mineral products has led to an increase in the exploitation of low-grade and complex ores, which often contain colloid clay particles that are detrimental to flotation and dewatering unit operations. The clay mitigation strategies employed during flotation (dilution and use of dispersants) and dewatering (addition of flocculants) involve reagents that can have deleterious consequences on the environment and aquatic biota. As part of an effort to find environmentally benign reagents, we evaluated the performance of six protein- and polysaccharide-based biopolymers for their potential as dispersants and/or flocculants of clay particles. Their effectiveness was assessed via froth flotation, settling, and filtration tests. Zeta potential, adsorption isotherm by total organic carbon (TOC), and quartz crystal microbalance with dissipation (QCM-D) tests were also conducted to understand the interactions between biopolymers and clay mineral surfaces. The anionic polysaccharide pectin showed promising dispersant efficiency in flotation at pH 10, and the cationic protein protamine significantly improved clay flocculation in dewatering operation at both pH 7 and 10. Outcomes of this study were proved that commercially available biopolymers have a significant potential to use in the treatment of clays in both flotation and dewatering processes and decrease environmental problems that occur by using inorganic and organic reagents.