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Abstract

Rigid spargers are attracting renewed interest in some applications of flotation columns, such as deinking of recycled paper, deoiling of water and the recovery of metallic ions from hydrometallurgical solutions. The main factors to be taken into consideration in the selection of a sparger are the characteristics of the sparger (material and geometry), the nature of the pulp to be processed (e.g. per cent solids and presence of surfactants) and the dimensions of the column. Lacking so far has been a method of estimating bubble size or gas hold-up (or bubble surface-area flux) for a given combination of sparger, column and pulp, which must account for the formation of a bubble swarm at the sparger and the rise of the swarm against a countercurrent flow of pulp or water. The method now proposed predicts gas hold-up by combining two models: one for bubble formation at the sparger, which relates bubble size to sparger and pulp characteristics; and the second for bubble flow, which relates bubble size to gas hold-up and phase hydrodynamics. Application of the method is illustrated for a set of porous, stainless-steel spargers installed in a column that was run with water and frother.

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References

Finch

J. A.

and Dobby

G. S

. Column flotation (New York: Pergamon, 1990), 9–58.

Watson

J. A.

, Gómez

C. O.

and Finch

J. A

. De-inking of recycled paper using column flotation. In Gómez C. O. and Finch J. A. eds Column ‘96. Proc. international symposium on flotation columns, Montreal, Canada, 26-28 August, 1996 (Montreal: CIM, 1996), 195–207.

Takahashi

, Miyahara

and Nishizaki

. Separation of oily water by bubble column. J. chem. Engng Japan, 12, no. 5, 1979, 394–9.

Strickland

W. T

. Laboratory results of cleaning produced water by gas flotation. Soc. Petroleum Engineers y, June 1980, 175–90.

Van Ham

N. J

., Behie

Svreck

L. A. W. Y.

The effect of air distribution on the induced air flotation of fine oil in water emul-sions. Can. J. chem. Engng, 61, August 1983, 541–7.

Castro Silva

M. E. M.

, Gazzi Salum

M. J.

and Correa de Araujo A. Precipitate flotation for the removal of heavy metals and cyanide from metallurgical effluents. In Proc. XVIII International Mineral Processing Congress, Sydney, 1993 (Carlton, Vic.: AusIMM, 1993), 1429–34.

Rybas

Ecological outlook for the new technology of the copper-nickel ore beneficiation based on the flotation with nitrogen. Reference 6, 997–8.

Tavera

F. J.

Flotación de Ni-Deta en medios acuosos: aplicación de columnas de flotación. Paper accepted for publication in AFINIDAD, Barcelona.

Gorain

B. K.

, Manlapig

E. V.

, and Franzidis

J. P

. The effect of gas dispersion properties on the kinetics of flotation. Reference 2.

10.

Ramakrishnan

, Kumar

and Kuloor

. Studies in bubble formation, 1 bubble formation under constant flow conditions. Chem. Engng Sci., 24, 1969, 731–47.

11.

Kumar

and Kuloor

N. R

. Advances in chemical engineering, vol. 8 (New York: Academic Press, 1970), 225–368.

12.

Dobby

G. S.

, Yianatos

J. B.

and Finch

J. A

. Estimation of bubble diameter in flotation columns from drift flux analysis. Can. Metall. Q., 27, no. 2, 1988, 85–90.

13.

Yianatos

J. B.

Bubble size estimation in a bubble swarm. J. Colloid Intel-ace Sci., 126, no.1, 1988, 37–44.

14.

Gomez

C. O.

, Escudero

and Finch

J. A

. Determining equivalent pore diameter for rigid porous spargers. Can. J. chem. Engng, 78, 2000, 785–92.

15.

American Petroleum Institute (API). Recommended practice for determining permeability of porous media, 1956.

16.

Carman

P. C

. Transport phenomena in porous media (New York: Academic Press Inc., 1956), 1-1 8.

17.

Scheidegger

A. E

. The physics of flow through porous media (Toronto: University of Toronto Press, 1974), 73–150.

Predicting gas hold-up in flotation columns from the physical characteristics of rigid spargers

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