Mill system closure and trash catching porous fillers in papermaking.
This study evaluated the possible use of porous sodium aluminosilicate (zeolite) as a wet end filler and as a white water clarifier in dissolved air flotation. Micro flocs generated by highly porous sodium aluminosilicates replaced magnesium silicate in the wet end. The result was better retention and minimized suspended solids in white water. We found that interaction between porous sodium aluminosilicate and negatively charged suspended or colloidal matters or other anionic by-products possibly derived from peroxide bleached pulp, resulted in agglomerates that could be partially removed by flotation. A partial elimination of anionic trash from white water also helped to improve first pass filler retention. It has been found that retention and drainage are inherently associated with the white water consistency, most importantly fiber and filler characteristics. A porous sodium aluminosilicate was effective under neutral conditions. Morphological analysis of floc-structure revealed that both the floc size and size distributions are more uniform for porous fillers. The higher price of high brightness sodium aluminosilicate compared to a relatively less bright filler such as magnesium silicate is expected to be offset by improved retention, brightness, and opacity. Improved white water quality is another advantage of porous sodium aluminosilicate.
Bourassa, Diamond, and Daneault are with Pulp and Paper Research Centre, University of Quebec, Trois-Rivieres, Quebec, Canada; Sain is associate professor, Earth Science Centre/Forestry, University of Toronto, 33 Willcocks Street, Toronto, ON, M5S 3B3, Canada. Email Sain at firstname.lastname@example.org.
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|Title Annotation:||Papermaking Additives|
|Publication:||Solutions - for People, Processes and Paper|
|Date:||Feb 1, 2003|
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