STARTUP OF A LARGE INDUSTRIAL FLOTATION COLUMN FOR WHITEWATER CLEANING

摘要

Flotation in a laboratory column was shown to selectively remove free organic extractives and extractive-laden fines from process waters in a mill making newsprint from thermomechanical pulp (TMP). These results prompted the mill to install a flotation column that would act as a kidney, treating a portion of recirculated paper machine cloudy Whitewater from the save all. A fully automated industrial flotation column of 33 m~3 with 2.4 m in diameter and 7.8 m in height was designed by FPlnnovations. During the startup, the flotation column removed 30-45 % of the total organic extractives from the paper machine save all cloudy Whitewater and improved the brightness by 2.5-3.0 points. Of the approximately 10% total solid loss from the Whitewater during flotation, 4% of the total solids were organic extractives with the remaining 6% comprised of fines. The column is under continuous operation since mid-April 2011.