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Sedimentation characteristics of two commercial bentonites in aqueous suspensions

Published online by Cambridge University Press:  09 July 2018

S. Akther ,
J. Hwang  and
H. Lee
S. Akther
Affiliation:
Division of Earth and Environmental Science Systems, Pusan National University, Busan 609-735, Korea
J. Hwang
Affiliation:
Division of Earth and Environmental Science Systems, Pusan National University, Busan 609-735, Korea
H. Lee*
Affiliation:
Division of Earth and Environmental Science Systems, Pusan National University, Busan 609-735, Korea
*
*E-mail: hmlee61@hotmail.com
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Abstract

The sedimentation characteristics of two commercial bentonites, Tixoton (organically treated) and Montigel-F (untreated), were investigated using a 3% w/v clay suspension at different concentrations (1, 3.5 and 10%) of NaCl and pH values (2, 7 and 12). Settling rates, floc diameters and sediment volumes were derived from changes in light transmittance using a Turbiscan Ma 2000 instrument.

Both bentonite suspensions were unstable (flocculated) in NaCl solutions. The settling rate increased with increasing concentration of NaCl and was directly related to floc diameter. The sediment volume reduced with increasing NaCl concentrations, a result of greater double layer compression caused by increased ionic strength. At comparable salt concentrations, the organically-treated bentonite (Tixoton) settled at a much slower rate and had a greater sedimentation volume. The suspensions of both organically-treated and untreated bentonites were stable (dispersed) above pH 7 and unstable in acidic conditions. The settling rate for Tixoton under acid conditions was much smaller than that for the Montigel-F. Differences in sedimentation characteristics between the two bentonite samples are probably due to the presence of an anionic polymer (carboxymethyl cellulose: CMC) in Tixoton.

The viscosity of the bentonite suspensions was also studied. The viscosity of the clay suspension is closely related to clay dispersivity in solution. The CMC was highly effective in increasing the viscosity of the bentonite suspensions, but only under neutral and alkaline conditions.

Keywords

bentonitesuspensiondispersionflocculationsettling ratesediment volumeNaClpHdrilling fluidviscosity
Type
Research Article
Information
Clay Minerals , Volume 43 , Issue 3 , September 2008 , pp. 449 - 457
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 2008

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References

Abend, S. & Lagaly, G. (2000) Sol-gel transition of sodium montmorillonite dispersions. Applied Clay Science, 16, 201–227.Google Scholar
Akther, S., Hwang, J.Y. & Lee, H. (2007) The effects of the water quality on the dispersion properties of bentonites used for drilling fluid. The Mineralogical Society of Korea, 20, 21–33.Google Scholar
Brandenburg, U. & Lagaly, G. (1988) Rheological properties of sodium montmorillonite dispersions. Applied Clay Science, 3, 263–279.Google Scholar
Caenn, R. & Chillingar, G.V. (1996) Drilling fluids: State of the art. Petroleum Science and Engineering, 14, 221–230.Google Scholar
Chen, J.S., Cushman, J.H. & Low, P.F. (1990) Rheological behavior of Na-montmorillonite suspensions at low electrolyte concentration. Clays and Clay Minerals, 38, 57–62.Google Scholar
Ece, O., Gungor, N. & Alemdar, A. (1999) Influences of electrolytes, polymer and a surfactant on rheological properties of the bentonite-water system. Inclusion Phenomena and Macrocyclic Chemistry, 33, 155–168.Google Scholar
Erdogan, B. & Demirci, S. (1996) Activation of some Turkish bentonites to improve their drilling fluid properties. Applied Clay Science, 10, 401–410.Google Scholar
Gungor, N. (2000) Effect of the adsorption of surfactants on the rheology of Na-bentonite slurries. Applied Polymer Science, 75, 107–110.Google Scholar
Giinister, E., Isic, S., Alemdar, A. & Gungor, N. (2004) Effect of sodium dodecyl sulfate on flow and electrokinetic properties of Na-activated bentonite dispersions. Bulletin of Materials Science, 27, 317–322.CrossRefGoogle Scholar
Giiven, N. (1992) Rheological aspects of aqueous smectite suspensions. CMS Workshop Lectures Volume 4, Clay-water Interface and its Rheological Implications. The Clay Minerals Society, 82–125.Google Scholar
Heller, H. & Keren, R. (2002) Anionic polyacrylamide polymers effect on rheological behavior of Namontmorillonite suspensions. Soil Science Society of America, 66, 19–25.Google Scholar
Hwang, J.Y. & Dixon, J.B. (2000) Flocculation behavior and properties of Na-montmorillonite treated with four organic polymers. Clay Science, 11, 137–146.Google Scholar
Keren, R. (1988) Rheology of aqueous suspensions of sodium/calcium montmorillonite. Soil Science Society of America, 52, 924–928.CrossRefGoogle Scholar
Luckham, P.F. & Rossi, S. (1999) The colloidal and rheological properties of bentonite suspensions. Advances in Colloid and Interface Science, 82, 43–92.Google Scholar
Mahto, V. & Sharma, V.P. (2004) Rheological study of a water based oil well drilling fluid. Petroleum Science and Engineering, 45, 123–128.Google Scholar
Meunier, A. (2005) Surface Properties, Behaviour Rules, Microtextures. Clays. Springer, Berlin, Heidelberg, New York, 191–230.Google Scholar
Permien, T. & Lagaly, G. (1994) The rheological and colloidal properties of bentonite dispersions in the presence of organic compounds: IV. Sodium montmorillonite and acids. Applied Clay Science, 9, 251–263.Google Scholar
Permien, T. & Lagaly, G. (1995) The rheological and colloidal properties of bentonite dispersions in the presence of organic compounds: V. Bentonite and sodium montmorillonite and surfactants. Clays and Clay Minerals, 43, 229–236.Google Scholar
Sato, T. & Ruch, R. (1980) Stabilization of Colloidal Dispersions by Polymeric Adsorption. Marcel Dekker, New York.Google Scholar
Tombacz, E. & Szekeres, M. (2004) Colloidal behavior of aqueous montmorillonite suspensions: the specific role of pH in the presence of indifferent electrolytes. Applied Clay Science, 27, 75–94.CrossRefGoogle Scholar