Flotation Technology || Treatment of Paper Mill Whitewater, Recycling and Recovery of Raw Materials

✍ Scribed by Wang, Lawrence K.; Shammas, Nazih K.; Selke, William A.; Aulenbach, Donald B.

• Book ID: 120246349
• Publisher: Humana Press
• Year: 2010
• Tongue: English
• Weight: 423 KB
• Edition: 2010
• Category: Article
• ISBN: 1603271333
• DOI: 10.1007/978-1-60327-133-2_7

✦ Synopsis

The characteristics and application of titanium dioxide and other fillers in the paper industry are introduced, the filler retention is defined, and the resources in whitewater and conventional processes are presented. Topics covered include a description of the paper industry, paper mill discharges, whitewater treatment and reuse, raw material recovery, opacity and fillers, available treatment technologies, and a study of a dissolved air flotation (DAF) process for recovery of fiber and titanium dioxide.The opacifying power of titanium dioxide as usually recovered by DAF is diminished by the persistence of the flocs necessary for the flotation. A recovery simulation to overcome that deficiency is described in which a cationic starch is used as the flotation aid, and the recovered solids are deflocced with enzymes. Handsheets were formed incorporating titanium recovered in this fashion for comparison with ones made with virgin titanium dioxide. The handsheets formed from this process had optical properties similar to those of papers made with the same amount of virgin filler over a large range of titanium dioxide contents in the paper.