Deep cone thickener

Deep-cone thickener, 22 65-66 Deep-sea manganese nodules, 15 542, 566-567... 

Figure 11.6. Thickeners for preconcentration of feed to filters or for disposal of solid wastes [see also the rake classifier of Fig. 12.2(e)]. (a) A thickener for concentrating slurries on a large scale. The rakes rotate slowly and move settled solids towards the discharge port at the center. Performance data are in Table 11.11 Brown, Unit Operations, Wiley, New York, 1950). (b) Deep cone thickener developed for the National Coal Board (UK), in a unit about lOftdia the impellers rotate at about 2rpm and a flow rate of 70 m3/scc with a solids content of 6wt%, concentrates to 25-35 wt % (Svarovsky, 1981).

Particle size 0.1 to 300 pm try to avoid using a thickener for particle diameters >200 pm, especially if their density is >2 Mg/mL Feed solids concentration 0.01 to 20% v/v exit liquid contamination in the solids exit 80 to 90% v/v liquid. Deep cone thickener exit liquid contamination in the solids exit 30 to 40% v/v liquid. 

Some materials such as mine tailings can be concentrated to a significant degree by these mechanisnis and a special apparatus, the deep cone thickener, has been developed for this purpose. 

The depth H of the deep-cone thickener is then obtained from the equation ... 

Alternative designs for gravity thickeners (a) circular-basin continuous thickener, (b) deep-cone thickener, and (c) lamella thickener. 

Deep cone thickener Lagoon thickener Lamella separator Settling tank thickener... 

Figure 1.5 Schematic representation of a deep cone thickener and inset photograph (Dorr-Oliver Eimco).

The discussion of chemical and physical pretreatments given in this chapter highlights the potential benefits (and pitfalls) of artificially changing the particle size present in a suspension. Chemical pretreatments in particular can enhance performance in all phases of a filter cycle and provide for improved filtration rates and reduced cake moistures. Some separation devices such as the deep cone thickener and belt filter press rely on the satisfactory performance of flocculants to function correctly and their use is a necessary prerequisite. The use of coagulants and flocculants with other separation devices must be assessed on an individual basis. Their introduction generally increases the operating cost of a separation which must be balanced by the potential improvements in separation characteristics. 

An unraked version of the deep cone thickener was developed for the thickening of red mud (insoluble residue from caustic digestion of bauxite... 

Abbott, J., Control systems and operational features of the deep cone thickener . Filtration Separation, July/August, 376-393 (1979)... 

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