- Title
- Application of electrostatically driven particle/droplet interactions to mineral separation
- Creator
- Ferguson, Joshua D.; Lobel, Benjamin T.; Thomas, Casey A.; Ireland, Peter M.; Wanless, Erica J.; Webber, Grant B.
- Relation
- Chemeca 2019 - Chemical Engineering Megatrends and Elements. Proceedings of the Chemeca 2019 - Chemical Engineering Megatrends and Elements (Sydney, N.S.W. 29 September - 2 October, 2019) p. 280-290
- Relation
- https://search.informit.org/doi/10.3316/informit.699729674475771
- Publisher
- Engineers Australia
- Resource Type
- conference paper
- Date
- 2019
- Description
- Our research group has developed a non-contact method for the formation of liquid marbles driven by electrostatic interactions between a dry particle bed and an approaching earthed water droplet. We have previously demonstrated the ability of this technique to physically separate coal and silica particles based on wettability; silica particles cross the air/water interface and penetrate the droplet while coal particles localise at the interface. Here we report on the application of the method to samples of haematite (Fe2O3), goethite (FeO(OH)) and silica (SiO2). Pure mineral samples were sieved to the 63 - 90 mum size fraction and tested using our custom-made electrostatic agglomeration rig. A dry particle bed of 2 - 5 mg was formed on a glass slide on a metal charging plate and the bed raised toward a pendent, earthed water droplet at 50 µm·s-1. The particles transfer, or jump, to the droplet as the electric field between the bed and droplet changes during approach, resulting in a net force on the particles. At applied voltages ranging from 1.5 - 3.0 kV the separation between the bed and particles when the particles were first observed to transfer was monitored. For each mineral the separation increased with applied voltage due to increased electric field strength. Pure goethite transferred most readily at all voltages as the drop-bed separation distance when the first particle was observed to jump was the greatest, whereas haematite and silica behaved similarly. High cohesion between goethite and haematite particles in mixed particle beds of both minerals resulted in particles transferring to the drop at separations between those observed for beds of the pure minerals. Careful determination of mineral composition of the dry bed and the transferred particle sample will indicate whether this approach may have potential application as a "rougher"-type step in the separation of goethite from haematite.
- Subject
- mineral separation; electrostatically driven particle/droplet interactions; particle/droplet interactions
- Identifier
- http://hdl.handle.net/1959.13/1448682
- Identifier
- uon:43461
- Identifier
- ISBN:9781925627336
- Language
- eng
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