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CHEMISTRY OF NOVEL HYDROPHOBIC AND SELECTIVE INTERACTIONS
Research Program Leaders
Professor Karen Hapgood, Professor George Franks, Associate Professor Liza Forbes
Overview
The overall objective of Program 2 is to support robust, fast, and efficient separation technologies that are both selective and hydrophobic. This is achieved by studying the effect of hydrophobic reagents on the surface properties and floatability of mineral particles. There was considerable progress in 2022 across all three sub-programs. Some of the highlights are given below.
2.1 Development of Novel Flotation Collectors
The objective of this sub-program is to develop novel reagents to enhance mineral surface hydrophobicity. The key highlights were:
Improved understanding of adsorption of novel synthetic and biopolymers and surfactants (from Program 3) to a range of surfaces, investigated through quartz crystal microbalance measurements.
Development of stable oil-in-water emulsions for application in coarse particle recovery, using conventional and novel surfactants (from Program 3). The emulsions have been investigated through creaming rate, zeta potential and droplet size measurements
2.2 Development of Novel Delivery Systems
The objective of this sub-program is to examine new ways of introducing reagent chemistries into mineral processing systems. The key highlights were:
Investigations into stabilising both water-inoil and oil-in-water emulsions using starch, cellulose, and fly ash.
Hydrophobic talc particles can be recovered with the use of a novel hydrophobic emulsion binder. Initial investigation has commenced regarding pre-aggregating the particles with a polymeric flocculant prior to binder agglomeration.
The benefits of placing collector on surfaces of bubbles (rather than mineral particles) to enhance coarse particle hydrophobicity is being investigated.
A series of thermo-responsive polymers (PNIPAM-based) via the RAFT process have been screened for their ability to stabilise water-in-oil emulsions for binder agglomeration. The best candidate has been found to be effective in recovering hydrophobic talc particles.
2.3 Hydrophobic Interactions in Dewatering
The objective of the third sub-program is to exploit mineral surface properties to improve suspension dewatering. The key highlights were:
Some objectives for 2023:
Investigation of the spreading of oils on mineral surfaces via combinations of novel surfactants and polymers.
Measurement of contact angles of mineral surfaces when treated with emulsion droplets stabilised by conventional and novel surfactants (from Program 3).
Personnel involved in Program 2 for 2022
Chief Investigators
Prof David Beattie, UniSA
Dr Susana Brito e Abreu, UQ
A/Prof Liza Forbes, UQ
Prof George Franks, UOM
L/Prof Kevin Galvin, UON
A team of researchers covering molecular dynamics and density functional analysis, RAFT polymerisation, surface physics, and novel beneficiation has established a possible way forward to improve the recovery and concentration of rare earth minerals. The industry partner has signed on for a second study.
Agglomerating with oil-in-water emulsions and flocculating clay particles has been investigated. Further processing via pelletisation was shown to improve the solid-liquid separation.
Chalcopyrite was found to selectively flocculate from quartz suspensions using conventional polymers. The high molecular weight was demonstrated to be a key polymer property. The potential for conventional surfactant collectors to make those aggregates hydrophobic for selective recovery via froth flotation was demonstrated.
In addition, there has been strong collaboration with Program 3 researchers supporting all three subprograms including:
A range of bespoke RAFT polymers and surfactants have been synthesised to test functionality and selectivity with model mineral systems in flocculation and flotation.
An initial set of novel peptide flotation collectors and depressants has been developed and tested for metal ion and surface selectivity.
Investigation of the influence of preaggregating fine particles with polymer on the amount of hydrophobic binder required to agglomerate and recover those particles.
Characterisation of the adsorption of novel polymers (from Program 3) on to mineral surfaces.
Initial comparison of the influence of collector addition either through the solution phase (conventional) or through the gas phase (novel).
Systematic investigation of the selective aggregation of chalcopyrite from quartz using different polymers.
Investigation of the flotation of copper bearing minerals with conventional and novel polymers sourced from Program 3.
Studies of bubbles attaching to oil-coated minerals using an oil-infused polymer layer as a planar oil-water interface for initial studies of bubble collisions.
A/Prof Marta Krasowska, UniSA
Dr Ellen Moon, Deakin
Prof Bill Skinner, UniSA
Dr Anthony Stickland, UOM
Prof San H. Thang, Monash
Prof Erica Wanless, UON
Prof Grant Webber, UON
Prof Chun-Xia Zhao, UoA
Associate Investigators
Dr Eirini Goudeli, UOM
A/Prof Kizuku Kushimoto, UOM
Ms Amalie Moller, UniSA
Research Associates
Dr Negin Amini, Deakin
Dr Amir Beheshti, UniSA
Dr Nilanka Ekanayake, UOM
Dr Bo Fan, Monash
Dr Casey Thomas, UOM
Dr Shane Usher, UOM
Dr Isabella Verster, UQ
Dr Junyu Wang, UQ
Dr Joshua Willott, UON
Dr Unzile Yenial Arslan, UQ
PhD Students
Ms Regina Medeiros, UOM
Mr Azeez Aregbe, UOM
Miss Candice Brill, UQ
Mr Yunzhou Qian, UOM
Mr Lequan Zeng, UOM
Mr Yuxuan Luo, UOM
Technical Staff
Mr Raul Cavalida, UOM
Ms Laura Jukes, UOM
Undergraduate Students
Zheng Xie, UOM
Declan Falls, UOM
Wenqian Li, UOM
Joshua Fink, UOM
Weizhe Peng, UOM
