- Title
- Upgrading of positively buoyant particles using an inverted reflux classifier
- Creator
- Kiani, A.; Zhou, J.; Galvin, K. P.
- Relation
- Chemeca 2013: Challenging Tomorrow. Chemeca 2013: Challenging Tomorrow: Proceedings (Brisbane, Qld 29 September-2 October, 2013) p. 357-362
- Relation
- https://www.icheme.org/events/events/2013/chemeca%202013.aspx#.Ve0N9JOu_hU
- Publisher
- Engineers Australia
- Resource Type
- conference paper
- Date
- 2013
- Description
- Cenospheres are hollow alumina silicate microshells found in fly ash. They are positively buoyant in water, thus allowing gravity-separation to be used to separate these low density particles from negatively buoyant fly ash particles. However, very low feed grade, of order 1%, and small particle diameter, typically less than 150 μmm, make achieving a reasonable throughput per unit vessel area difficult for conventional gravity-separation systems. In this study an Inverted Reflux Classifier (IRC) was used for the first time to recover and concentrate cenospheres from a real fly ash feed obtained from a coal fired power station. This novel, single stage, device consists of a system of parallel inclined channels, located beneath a partially enclosed vertical fluidizing chamber. The channels enhance the segregation rate of the cenospheres from the fly ash, permitting a greater downwards fluidization to aid the desliming of fine fly ash particles from the overflow product. The device was fed at a solids flux of about 2.6 t/m2h. A product grade of 75% was achieved from a feed with a grade of only 0.53%, corresponding to an upgrade of 142. Here, the recovery of the cenospheres was 41%. By increasing the overflow product rate, a significantly higher recovery of 64% was achieved, but at a much lower upgrade of 33. In both cases most of the losses were attributed to fine cenosphere particles, less than 50 μmm, being entrained to the underflow.
- Subject
- buoyant; cenosphere; fly ash; reflux classifier; fluidization
- Identifier
- http://hdl.handle.net/1959.13/1302573
- Identifier
- uon:20503
- Identifier
- ISBN:9781922107077
- Language
- eng
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