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Study of shear-flocculation of silica

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Abstract

The US Bureau of Mines investigated the fundamental aspects of shear-flocculation using a rapid, in-situ particle size analyzer. Silica was stirred in the presence of an aliphatic amine to determine the effects of collector coverage, stirring speed and solids concentration on the kinetics of shear-flocculation. The results showed that shear-flocculation is a two-stage process. In the first stage, which occurs during the first 1–2 min. of the reaction, the mean particle size increases rapidly, and in the second stage, an equilibrium is set up between the rates of floc growth and floc decay. Collector dosage affected the position of the equilibrium by altering the number of surface sites for particle-particle attachment. A minimum stirring speed was necessary for shear-flocculation, which was dependent on solids concentration and collector dosage. This stirring speed was the minimum necessary for particles to overcome the electrostatic energy barrier, and that results in keeping the conditioned particles dispersed. Larger particles flocculated more rapidly. At very high stirring speeds, large flocs became unstable, resulting in a narrowed particle size distribution in the slurry.

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References

  • Bilgen, S., and Wills, B.A., 1991, “Shear-flocculation—A review,” Minerals Engineering, Vol. 4. pp. 483–487.

    Article  Google Scholar 

  • Bischofberger, C., and Schubert, H., 1978, “On the hydrodynamics of flotation machines,” International Journal of Mineral Processing, Vol. 5, pp. 131–142.

    Article  Google Scholar 

  • Jordan, C.E., and Spears, D.R., 1990, “Evaluation of a turbulent flow model for fine-bubble and fine-particle flotation,” Minerals and Metallurgical Processing, May, pp. 65–73.

  • Jowett, A., 1980, “Formation and disruption of particle-bubble aggregation in flotation,” Fine Particle Processing, P. Somasundaran, ed., SME, pp. 720–754.

  • Kelley, E.G., and Spottiswood, D.J., 1982, Introduction to Mineral Processing, Wiley and Sons, New York.

    Google Scholar 

  • Koh, P.T.L., Andrews, J.R.G., and Ulherr, P.H.T., 1987, “Modeling shear-flocculation by population balances,” Chemical Engineering Science, Vol. 42, pp. 353–362.

    Article  Google Scholar 

  • Lucassen-Reynders, E.H., and Lucassen, J., 1984, “Thin films, contact angles, wetting,” in The Scientific Basis of Flotation, K.J. Ives, Ed., Nijhoff: The Hague, pp. 79–110.

    Chapter  Google Scholar 

  • Moudgil, B.M., and Vasudevan, T.V., 1989, “Characterization of flocs,” Flocculation and Dewatering, B.M. Moudgil and B.J. Scheiner, eds., Engineering Foundation, pp. 167–178.

  • Pashley, R.M., and Israelachvili, J.N., 1981, “A comparison of surface forces and interfacial properties of mica in purified surfactant solutions,” Colloids and Surfaces, Vol. 2. p. 169.

    Article  Google Scholar 

  • Raju, G.B., Subrahmanyam, T.V., and Forsling, W., 1991, “Shear-flocculation of quartz” International Journal of Mineral Processing, Vol. 32, pp. 283–294.

    Article  Google Scholar 

  • Sivamohan, R. and Cases, J.M., 1990, “Dependence of shear-flocculation on surface coverage and zeta potential,” International Journal of Mineral Processing, Vol. 28, pp. 161–172.

    Article  Google Scholar 

  • Spears, D.R., Stanley, D.A., and Scheiner, B.J., 1992, “Some aspects of the hydrodynamics and polymer conformation in polyacrylamide flocculation of chromed,” SME Reprint 92-93.

  • Subrahmanyam, T.V., and Forssberg, K.S.E., 1990, “Fine particles processing: Shear-flocculation and carrier flotation—A review,” International Journal of Mineral Processing, Vol. 30. pp. 265–286.

    Article  Google Scholar 

  • Sutherland, K.L., and Wark, I.W., 1955, Principles of Flotation, Australasian Institute of Mining and Metallurgy, Inc., pp. 347–378.

  • Warren, L.J., 1975, “Shear-flocculation of ultrafine scheelite in sodium oleate solutions” Journal of Colloid and Interface Science, Vol. 50, pp. 307–318.

    Article  Google Scholar 

  • Warren, L.J., 1982, “Flocculation of stirred suspensions of cassiterite and tourmaline,” Colloids and Surfaces, Vol. 5, pp. 301–319.

    Article  Google Scholar 

  • Woodbum, E.T., King, R.P., and Colburn, R.P., 1971, “The effect of particle size distribution on the performance of a phosphate flotation process,” Metallurgical Transactions, Vol. 2, pp. 3163–3174.

    Article  Google Scholar 

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Authors and Affiliations

  1. US Bureau of Mines, Tuscaloosa Research Center, Tuscaloosa, AL, USA

    D. R. Spears (member SME, research chemist) & D. A. Stanley (supervisory research chemist)

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  1. D. R. Spears
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  2. D. A. Stanley
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Additional information

SME Preprint 93-167, SME Annual Meeting, Feb. 16–18, 1993, Reno, NV. M&MP paper 93-621.

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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Spears, D.R., Stanley, D.A. Study of shear-flocculation of silica. Mining, Metallurgy & Exploration 11, 5–11 (1994). https://doi.org/10.1007/BF03403033

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  • DOI: https://doi.org/10.1007/BF03403033

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