THE MECHANISM OF FINES RETENTION USING PAM-BENTONITE SYSTEMS

  • Tom Asselman (Paprican and Department of Chemical Engineering Pulp and Paper Research Center McGill University) ;
  • Gil Garnier (Paprican and Department of Chemical Engineering Pulp and Paper Research Center McGill University)
  • Published : 1999.11.01

Abstract

The deposition kinetics of fines on fibres was studied to elucidate the flocculation mechanism of a PAM/bentonite retention aid. It is shown that polymer-induced co-flocculation is not permanent. This phenomenon is attributed to a stabilising effect of polymer transfer between surfaces. The resulting polymer layers have a reduced bridging ability with naked surfaces. The addition of bentonite increases the bond strength between fibres and fines, and links non-briding layers. These results explain the positive influence of bentonite on fines retention.

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