The name is absent

Chapter 4

Д£ ₍c,+c_{2) =} ζ(c₂)-ζ(c_l)
∆c 2        c₂- c₁

Here ζis zeta potential and c is concentration of the additive.

0-----------------^ι-----------------^ι------. .--------^ι----------------4.-.-.-.-.___—

------

-20

-4°       ∣∣

//         O Adding NaOH, with Ca/Mg

ill          O Adding NaOH, without Ca/Mg

'θθ ill            ∙ Adding carbonate, with Ca/Mg

∙∣∣             ∙  Adding carbonate, without Ca/Mg

.θQ _ Ш             + Adding metasilicate, with Ca/Mg _

!f              +  Adding metasilicate, without Ca/Mg

is               ∙  Adding orthosilicate, with Ca/Mg

-100 j/               *  AddingorthosiIicate_lWithoutCaZMg-

7               *  Adding citrate, with Ca/Mg

♦ Adding citrate, without Ca/Mg
-120----------------------^l----------------------^l----------------------^l----------------------'----------------------

0           0.2          0.4          0.6          0.8           1

Concentration (mM)

Figure 4.17 Zeta potentials change of kaolinite samples in synthetic brine

For hydroxide, citrate and carbonate, zeta potential change per unit additive
concentration is around 15-25 mV∕mM. But for meta- silicate or ortho-silicate,
zeta potential change is much larger than other additives at low concentration
(<10^⁴ M). And zeta potential change decreases very fast with the increase of
silicate concentration. Compare with other anions, silicate ions have the greatest
effect per unit addition on changing zeta potential of kaolinite.

122

<<   135   136   137   138   139   140   141   >>

More intriguing information