Recovery of Waste Coating By Ultrafiltration, 1992 Environmental Conference Proceedings
The ASSI Frovifors Bruk coated board mill in Frovi, Sweden, recently purchased a membrane filtration system to recover and concentrate the waste coating from the air-knife coater. The primary objective was effluent abatement, with the recovery of valuable re-usable coating colour as a secondary benefit. Lost coating is recovered at the 0.5 - 2% solids range and concentrated in two cross rotational membrane filters to approximately 46% solids. The system is designed to treat 20 m 3 /h coating effluent.
Operational experience since start-up in late 1991 is discussed, with emphasis on recovered coating colour quality, flux stability, and economics of colour recovery. If all separated pigment can be re-used a short pay-back time is expected - well under two years.
The same concept can be applied to intermittent coating losses, e.g. blade coaters.
Recovery of Waste Coating By Ultrafiltration, 1992 Environmental Conference Proceedings
