Influence of flotation tailings thickening on centrifugal flocculation performance
The dewatering and utilization of coal-cleaning wastes are important problems in connection with the control of air and water pollution in industrial areas and the recycling of production wastes in general. The most intractable technical problem is how to treat the very finely divided suspensions of flotation tailings to recover clean water for recycling and a handleable sludge. Centrifugal flocculation is an effective method of dewatering flotation tailings and has been adopted commercially in many Soviet and foreign coal washeries. The object of this investigation was to explore the effects of preliminary thickening on the performance of the centrifugal flocculation section. Research was needed since no practical information is available and there is a conflict of opinion between various authorities on the subject. Laboratory test data are presented to support the conclusion that flotation tailings should be thickened (to a solids content of 200 to 350 g/l) before centrifugal flocculation. The PAA input must be increased to flocculate the increased solids content. Visual observations established that the cake formed in the dewatering centrifuge from the thicker suspensions is a rigid solid mass quite suitable for transport. Although the cake formed from more dilute suspensions contains only a little more moisture, it is weaker and more difficult to transport. Thus, the experimental evidence indicates that flotation tailings for centrifugal flocculation should be thickened to a high solids content (250 to 350 g/l). Thickening is also necessary as a means of reducing the volumetric load on the sedimentation centrifuge, which is one of the major performance factors. On the other hand, the specific flocculant consumption is increased.
- OSTI ID:
- 6306396
- Journal Information:
- Coke Chem. USSR (Engl. Transl.); (United States), Journal Name: Coke Chem. USSR (Engl. Transl.); (United States) Vol. 5; ISSN COKCA
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
015000* -- Coal
Lignite
& Peat-- Economic
Industrial
& Business Aspects
CARBONACEOUS MATERIALS
CENTRIFUGATION
COAL
COAL PREPARATION
COMMINUTION
DISPERSIONS
ENERGY SOURCES
FLOCCULATION
FLOTATION
FOSSIL FUELS
FUELS
HYDROGEN COMPOUNDS
LIQUID WASTES
MATERIALS
MIXTURES
OXYGEN COMPOUNDS
PRECIPITATION
REMOVAL
SEPARATION PROCESSES
SLURRIES
SOLID WASTES
SUSPENSIONS
TAILINGS
WASTE WATER
WASTES
WATER
WATER REMOVAL
WATER TREATMENT