Thickening of ultrafine coal-water slurries in a solid-bowl centrifuge
As part of a study being conducted for the Electric Power Research Institute's (EPRI's) Upgraded Coal Interest Group (UCIG) to evaluate ultrafine coal dewatering technologies, testing was carried out to investigate the use of a solid-bowl (high-g) centrifuge for thickening ultrafine coalwater slurries. The objective of this study was to increase the solids concentration to a level suitable for use as a coal-water slurry fuel, while maximizing overall solids recovery. Feed material was collected from the combined discharge (centrate) streams from several screen-bowl centrifuges. These devices are currently being used in a commercial coal cleaning facility to dewater the clean coal product from a froth flotation circuit. Current plant practice is to discharge the centrate to settling ponds. The screen bowl centrate averages 5% solids by weight and contains nearly 60% material finer than 10 {mu}m. The current study examined the effects of operating conditions on centrifuge performance. The test conditions included centrifuge bowl and scroll speeds and volumetric feed rate. In addition to thickening, some cleaning was also achieved, because the finest particles (e.g. < 3 {micro}m), which contained a large percentage of liberated clays, were removed with the bulk of the water. The centrifuge products were analyzed for solids concentration, particle size distribution, and ash content. Size selectivity curves were also used to evaluate centrifuge performance.
- Research Organization:
- Pennsylvania State Univ., University Park, PA (US)
- Sponsoring Organization:
- Electric Power Research Institute
- OSTI ID:
- 20013421
- Resource Relation:
- Conference: 24th International Technical Conference on Coal Utilization and Fuel Systems, Clearwater, FL (US), 03/08/1999--03/11/1999; Other Information: PBD: [1999]; Related Information: In: The proceedings of the 24th international technical conference on coal utilization and fuel systems, by Sakkestad, B.A. [ed.], 1091 pages.
- Country of Publication:
- United States
- Language:
- English
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