• colloidal gel;
  • gelation;
  • polymer colloid;
  • operation unit


A continuous and fast gelation unit, referred to as a single-stage mechanically agitated gelation column has been proposed to perform gelation of colloidal systems. A fluorinated polymer latex, MFA®, has been used. The column is initially filled with a coagulant solution at a concentration that fully destabilizes the colloid. Under agitation, the colloid is fed continuously to the discharging region of the agitator blades where it forms flocs of gel by mixing with the coagulant. If the density of the colloidal particles is larger than that of water, the flocs settle downward to the bottom of the column and flow out of the unit for further treatment or direct applications. Timescale analysis of the phenomena involved in the column has been carried out to understand the complex interplay between gelation and mixing. Various gelation regimes have been identified, which can interpret the observed gelation behavior in the column. © 2008 American Institute of Chemical Engineers AIChE J, 2008