Application of an enhanced gravity separator for cleaning fine coal
- CSIRO Div. of Coal and Energy Technology, Kenmore (Australia)
The efficiency of cleaning fine coal by gravity separation methods for particle sizes less than 0.250mm is low. Units such as water washing cyclones and spirals have been successfully employed for the coarser size fractions, but significant losses of fine coal have been observed in these applications. Flotation has also been successfully used, but it has a high ``effective`` separation density (about 2), and is a relatively expensive unit operation with regard to operating costs. Recently the Kelsey Centrifugal Jig was developed for concentrating minerals using centrifugal force in the range of 30 to 200G. This is achieved by rapidly spinning a cylindrical screen and injecting the feed at its bottom edge. Water is pulsed through the screen as the material is forced up the screen by the new incoming feed. A ragging bed of the coarser higher density particles forms on the screen. A project has recently been completed in which the capabilities of this unit were investigated in two coal preparation plants at pilot scale level on typical run of mine fine coal. Comparative studies were conducted on spirals and a laboratory Jameson flotation cell with the same feed material. The centrifugal jig was able to be operated in preparation plants provided tramp oversize material was excluded from the feed. It could separate coal from shale at very fine sizes (at least 0.038mm), but its capacity is limited by the amount of refuse which needs to be removed. With respect to the recovery of fine coal, the Jameson flotation cell was able to produce high refuse ash values when taken to completion.
- OSTI ID:
- 143766
- Report Number(s):
- CONF-9305264-; TRN: IM9413%%276
- Resource Relation:
- Conference: COAL PREP `93: 10th international coal preparation exhibition and conference, Lexington, KY (United States), 4-6 May 1993; Other Information: PBD: 1993; Related Information: Is Part Of Coal prep `93: 10th international coal preparation exhibition and conference; PB: 298 p.
- Country of Publication:
- United States
- Language:
- English
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