Abstract
The dewatering of flocculated clay suspensions by compression in a centrifugal field was investigated. The results were analyzed with respect to the direct applicability of centrifugal dewatering (as in solid-bowl centrifuges) and indirect applications to gravity sedimentation systems. An important objective of the study was to evaluate the self-weight effect using centrifugal forces to simulate consolidation of deep sediments.
Experiments were conducted in which the sediment mass and initial structure were maintained constant while the effective sediment weight was varied by centrifuging at different speeds. The relationship between the limiting sediment density and the applied consolidation stress was found to be the same for both gravity and centrifugal consolidation, indicating that small-scale laboratory tests can be used to predict consolidation in deep beds.
The effects of the initial structure were also studied using controlled variations in flocculation conditions. The results imply that, for the flocculated suspensions studied, the long-term consolidation behavior is relatively insensitive to the actual extent of flocculation.
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References
Chandler, J.L., 1989, “Dewatering red mud by deep thickening and solar evaporation,” Flocculation and Dewatering, B.M. Moudgil and B.J. Scheiner, eds., Engineering Foundation, New York, NY, pp. 539–548.
Hogg, R., and Bunnaul, P., 1992, “Sediment compressibility in thickening of flocculated suspensions,” Minerals and Metallurgical Processing, Vol. 9, pp. 184–188.
Hogg, R., Bunnaul, P., and Suharyono, H., 1993, “Chemical and physical variables in polymer-induced flocculation,” Minerals and Metallurgical Processing, Vol. 10, pp. 81–86.
Hogg, R., Klimpel, R.C., and Ray, D.T., 1987, “Agglomerate structure in flocculated suspensions and its effects on sedimentation and dewatering,” Minerals and Metallurgical Processing, Vol 4, pp. 108–113.
Keys, R.O., and Hogg, R., 1979, “Mixing problems in polymer flocculation,” AIChE Symposium Series, No. 190, Vol. 75, pp. 63–72.
Klimpel, R.C., and Hogg, R., 1991, “Evaluation of floc structures,” Colloids and Surfaces, Vol. 55, pp. 279–288.
Kynch, G.J., 1952, “A theory of sedimentation,” Transactions of the Faraday Society, Vol. 48, pp. 166–176.
Sutherland, D.N., 1967, “A theoretical model of floc structure,” Journal of Colloid Interface Science, Vol. 25. pp. 373–380.
Townsend, F.F., Bloomguist, D.G. and McClimans, S.A., 1985, “Evaluation of reclamation schemes by centrifugal modeling,” Flocculation Sedimentation and Consolidation, B.M. Moudgil and P. Somasundaran, eds., Engineering Foundation, New York, NY, pp. 471–487.
Vold, M.J., 1963, “Computer simulation of floc formation in a colloidal suspension,” Journal of Colloid Interface Science, Vol. 18, pp. 684–695.
Welland, R.H., 1992, “Centrifugal sedimentation of flocculated clay particles,” unpublished Undergraduate Research Report, Department of Mineral Engineering, Pennsylvania State University, University Park, PA.
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SME Preprint 93-259, SME Annual Meeting, Feb. 15–18, 1993, Reno, NV. M&MP paper 93-610.
Discussion of this peer-reviewed and approved paper is invited and must be submitted, in duplicate, prior to May 31, 1994.
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Weiland, R.H., Bunnaul, P. & Hogg, R. Centrifugal dewatering of flocculated clays. Mining, Metallurgy & Exploration 11, 37–40 (1994). https://doi.org/10.1007/BF03403038
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DOI: https://doi.org/10.1007/BF03403038