Chapter 4
Figs.4.29 and 4.30 show zeta potential of kaolinite in synthetic brine adding
Na2SiO3 or Na4SiO4. The blue dashed curve shows the fitted zeta potential of
kaolinite without Ca/ Mg. The red solid curve shows the fitted zeta potential of
kaolinite with Ca/ Mg.
x 10
c (Na2SiO3) (M)
Figure 4.29 Kaolinite zeta potential in synthetic brine adding Na2SiO3, pH 8.3 - 9.0
At low concentration of silicate (0.05 mM), zeta potential change per unit
additive concentration is around 100 -110 mV∕mM, which is about five times of
that adding sodium hydroxide (20 mV∕mM). With the increase of silicate
concentration, zeta potential change per unit additive concentration decreases to
around 30 mV∕mM. Meta-silicate and ortho-silicate have the similar effects on zeta
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