Column Flotation Deinking: State-of-the-art and opportunities

Flotation is a critical process step for ink removal from recycled paper. Column flotation is a specific form of flotation that has grown in popularity recently. Extensive efforts during the past four decades to improve the flotation deinking operation sought an optimum blend of technological parameters, physico-chemical aspects and economical process conditions. With increasing demand to recover and recycle waste paper due to ecological and economical concerns, there is a need for an improved process and therefore for in-depth understanding of the mechanism and fundamental factors involved in the efficiency and economics of the deinking process. This paper reviews the progress made in the last decade (2000–2010) in deinking hydrodynamics, various measurement techniques, scale-up and design criterion.

► Flotation deinking provides a high yield of fibres, i.e., a low amount of rejects.
► It enhances pulp brightness by removing ink particles and improves cleanliness.
► It partly removes fillers and provides partial de-ashing, to prevent “ash collapse”.
► Review was done on column flotation deinking hydrodynamics, measurement techniques and scale-up.