TY - JOUR
T1 - Rheology of sodium and calcium bentonite-water dispersions
T2 - Effect of electrolytes and aging time
AU - Abu-Jdayil, Basim
N1 - Funding Information:
This work was financially supported by the Research Affairs at the UAE University under contract no. 02-02-7-11/08 . Special thanks are due to Mr. Hassan Kamal for his help in the experimental work.
PY - 2011/3/9
Y1 - 2011/3/9
N2 - Bentonitic clays are largely composed of the mineral montmorillonite. Today, bentonites are used in different branches of industry, such as in drilling fluids, dyes, Pharmaceuticals, paper, cement, nanocomposites, polymer composites and ceramics. Bentonite dispersions are widely used in industrial processes because of their exceptional rheological behavior. In this work, the rheological behavior of three types of bentonites with different Na +/Ca+ 2 ratios was investigated. The bentonite dispersions showed Newtonian, Bingham plastic and shear thinning behaviors depending on the solid concentration and bentonite type. Although, all bentonite dispersion exhibited a thixotropic behavior, the Na-bentonite showed a greater degree of thixotropy which was two order of magnitudes greater than that of Ca-bentonite. The rheological behavior of bentonite suspensions developed significantly in the first 24 h of preparation. The addition of electrolytes in a concentration range of 0.02-0.2 M reduced the apparent viscosity of the bentonite suspensions and changed its rheological behavior from shear thinning to Newtonian and shear thickening. The divalent cation salts experienced more reduction in the apparent viscosity and yield stress of suspension than the monovalent cation salts.
AB - Bentonitic clays are largely composed of the mineral montmorillonite. Today, bentonites are used in different branches of industry, such as in drilling fluids, dyes, Pharmaceuticals, paper, cement, nanocomposites, polymer composites and ceramics. Bentonite dispersions are widely used in industrial processes because of their exceptional rheological behavior. In this work, the rheological behavior of three types of bentonites with different Na +/Ca+ 2 ratios was investigated. The bentonite dispersions showed Newtonian, Bingham plastic and shear thinning behaviors depending on the solid concentration and bentonite type. Although, all bentonite dispersion exhibited a thixotropic behavior, the Na-bentonite showed a greater degree of thixotropy which was two order of magnitudes greater than that of Ca-bentonite. The rheological behavior of bentonite suspensions developed significantly in the first 24 h of preparation. The addition of electrolytes in a concentration range of 0.02-0.2 M reduced the apparent viscosity of the bentonite suspensions and changed its rheological behavior from shear thinning to Newtonian and shear thickening. The divalent cation salts experienced more reduction in the apparent viscosity and yield stress of suspension than the monovalent cation salts.
KW - Aging time
KW - Bentonite
KW - Bingham fluid
KW - Electrolyte
KW - Rheology
KW - Shear thinning
KW - Thixotropy
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U2 - 10.1016/j.minpro.2011.01.001
DO - 10.1016/j.minpro.2011.01.001
M3 - Article
AN - SCOPUS:79952003745
SN - 0301-7516
VL - 98
SP - 208
EP - 213
JO - International Journal of Mineral Processing
JF - International Journal of Mineral Processing
IS - 3-4
ER -