Abstract
The flocculation and subsequent subsidence of colloidal suspensions are markedly increased by the addition of flocculating agents; for example various starches and recently developed synthetic polymers.
The rate of flocculation depends not only upon the extent of adsorption of the agent (flocculant) but also upon the order of mixing and the character and extent of the subsequent agitation which determines the character of the floc formed. Electrolytes flocculate by reducing the electrostatic repulsions between charged particles, but long chain polymers produce flocs by a bridging mechanism which overcomes electrostatic repulsions.
Quantitative relationships are developed between the optimum concentration of flocculant and the rates of flocculation, subsidence, and particularly rate of filtration through the filter cake.
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La Mer, V. K. and Smellie, R. H. (1952) Progress report, Colloidal characteristics and behavior of some Florida phosphate slimes: N.T.O. 3286.
La Mer, V. K. and Smellie, R. H. (1952) Progress report, Colloidal characteristics and behavior of some Florida phosphate slimes: N.Y.O. 3288.
La Mer, V. K. and Smellie, R. H. (1956a) Flocculation, subsidence, and filtration of phosphate slimes, I. General: J. Colloid Sci. v. 11, 704–709.
La Mer, V. K. and Smellie, R. H. (1956b) Flocculation, subsidence and filtration of phosphate slimes, II. Starches as agents for improving flocculation, subsidence, and filtration: J. Colloid Sci., v. 11, 710–719.
La Mer, V. K. and Smellie, R. H. (1956c) Flocculation, subsidence and filtration of phosphate slimes. Subsidence behavior: J. Colloid Sci., v. 11, 720–731.
La Mer, V. K., et al. (1953) Progress report, Colloidal characteristics and behavior of some Florida phosphate slimes: N.Y.O. 3288 (Subsidence Theory). (NOPCO polymers and potential determining ions as yet unpublished.)
La Mer, V. K. et al. (1954a) Preliminary discussion of filtration theory: N.Y.O. 3289.
La Mer, V. K. et al. (1954b) Particle size distribution and specific surface studies on phosphate slimes. Kozeny-Carman equation: Progress Rept. N. Y.O. 7402.
La Mer, V. K. et al. (1956) The preparation and evaluation of superior flocculating agents for phosphate slimes: Progress Rept. N. Y.O. 7403. (Preparation and testing of suspension flocculating agents in respect to molecular weight, hydrolysis, cross linking and salt effects; also dependence upon weight percent solids.)
La Mer, V. K., et al. (1957a) Flocculation, subsidence and filtration of phosphate slimes. Flocculation by gums and polyelectrolytes and their influence on filtration rate: J. Colloid Sci., v. 12, 230–239.
La Mer, V. K. et al. (1957b) Flocculation, subsidence and filtration of phosphate slimes. The optimum filtration rate as a function of solid content and specific area: J. Colloid Sci., v. 12, 566–574.
Meyer, K. H. et al. (1948) J. Phys. Colloid Chem., v. 53, p. 319.
Michaels, A. S. and Morelos, O. (1955) Ind. Eng. Chem., v. 47, p. 1801.
Ruehrwein, R. A. and Ward, D. W. (1952) Mechanism of clay aggregation by polyelectrolytes: Soil Sci., v. 73, 485–492.
Scheidegger, A. E. (1957) The Physics of Flow through Porous Media: MacMillan, New York.
Smellie, R. H., Jr. and La Mer, V. K. (1958) Flocculation, subsidence and filtration of phosphate slimes. A quantitative theory of filtration of flocculated suspensions: J. Colloid Sci., v. 13, 589–599.
Umberger, I. Q. and La Mer, V. K. (1945) The kinetics of diffusion controlled molecular and ionic reactions: J. Amer. Chem. Soc, v. 67, 1099–1109.
Verwey, E. J. W. and Overbeek, J. Th. G. (1948) Theory of the Stability of Lyophobic Colloids: Elsevier Publishing Co., Inc., New York, 205 pp.
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La Mer, V.K., Smellie, R.H. Theory of Flocculation, Subsidence and Refiltration Rates of Colloidal Dispersions Flocculated by Polyelectrolytes. Clays Clay Miner. 9, 295–314 (1960). https://doi.org/10.1346/CCMN.1960.0090118
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DOI: https://doi.org/10.1346/CCMN.1960.0090118