Flocculation types

The pressing time for any clay under given conditions depends on its permeability to water, which in turn depends on the exchangeable ions. If they are of the flocculating type (e.g. H" ", Ca, or Mg " ) the clay is permeable to water and rapidly forms a firm press-cake. On the other hand, if the exchangeable ions are predominantly Na or, filter-pressing is difficult and the press-cakes are often watery . 

Flocculant Type Functional group Adsorption mechanism... 

Figure 3.9 Chemical compositions and structures of some common flocculant types.

Amounts 0.5 to 1.5 mg l of flocculant (type 1 polymer) generally in powder or sometimes anionic polymer. 

The combination of lime and heat forms a flocculent-type precipitate with various components in the juice, which consist mostly of insoluble lime salts, coagulated protein, and entrapped colloidal and suspended matter. The precipitate is removed by sedimentation or settling in continuous closed-tray clarifiers (i.e., Rapi-Dorr, Graver, BMA, and Bach Poly-Cell). The juice leaving the clarifier is a clear brownish liquid. 

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