- Title
- Investigation of a Novel Emulsion Binder for Recovering Ultrafine Hydrophobic Particles
- Creator
- De Iuliis, G.; Sahasrabudhe, G.; Borrow, D. J.; Galvin, K. P.
- Relation
- Chemeca 2019: Chemical Engineering Megatrends and the Elements. Proceedings of Chemeca 2019: Chemical Engineering Megatrends and the Elements (Sydney 29 September - 02 October, 2019) p. 119-127
- Publisher
- Engineers Australia
- Resource Type
- conference paper
- Date
- 2019
- Description
- It is difficult to recover ultrafine mineral particles less than 20 mum using froth flotation due to the viscous energy barrier that exists between the particles and the surface of the air bubble. Thus, new and innovative beneficiation technologies are required to recover such particles. A novel process involving the agglomeration of hydrophobic ultrafine particles using a high internal phase water in oil emulsion has been developed to address this issue. The emulsion, which acts as a binder, is permeable, hence the ultrafine particles do not experience a viscous energy barrier prior to their adhesion with the emulsion. Selective agglomeration of silica, coal and magnetite with the emulsion binder has been achieved. The emulsion consists of an internal aqueous phase which hosts a network of tightly packed water droplets, 3 mum in diameter, surrounded by thin and continuous oil films which can adhere to hydrophobic particles. In this study, the oil film thickness is altered through variations in the emulsion composition. Key parameters investigated include the size of the internal water droplets within the emulsion, which subsequently influence the oil film thickness. The Sauter mean diameter of the water droplets was found to decrease with increasing concentration of the emulsifier, sorbitan monooleate (SMO), within the emulsion. It was also observed that when the emulsion was soaked in water, the size of the internal drops increased due to permeation of water by osmosis, causing the oil film thickness to decrease. Thinning of the films leads to a larger specific surface area of the oil and hence improved recovery of ultrafine hydrophobic particles. The kinetics of the permeation was quantified by measuring the change in the diameter of rivulets of the emulsion soaked in water. These results showed the macroscopic rate of permeation was diffusion controlled, reflecting a summation of the permeation at a more local level through the individual drops within the rivulet.
- Subject
- froth flotation; particles; aqueous phase; emulsion
- Identifier
- http://hdl.handle.net/1959.13/1453165
- Identifier
- uon:44614
- Identifier
- ISBN:9781925627336
- Language
- eng
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