Recovery of Titanium Dioxide from Paper Mill White Water

摘要

The paper examined the recovery of titanium dioxide pigment and paper fiber from a paper mill whitewater. The best recovery simulation results were found using a cationic starch retention aid (National 132), used with a cationic starch flotation aid (Cato 215), then dispersing the recovered sludge with either Tekalex or Enzeco enzyme. National 132 was then reintroduced as a retention aid and a paper handsheet was formed. The handsheets formed from this process had similar optical properties to those of papers made with virgin, untreated titanium dioxide over a large range of titanium dioxide contents in the paper. This indicates that the pigment in papermill whitewaters can be deflocculated and reintroduced into the system without greatly impairing the optical properties of the paper.