Current Deinking Process in European Newsprint Mills, 1990 Pulping Conference Proceedings

This paper discusses the process used in five recent news deinking plants located in England, Holland, Finland, and France. These deinking plants were started in the last three years and represent over 35% of the Western European deinking capacity for newsprint. Most of these plants have a similar process consisting of high consistency pulping, coarse-contaminant removal at the pulper, high-consistency cleaning, coarse screening with holes, cleaning, flotation deinking, centrifugal fine-screening with slots, light-reject cleaning, and thickening. Three of the plants have dispersion. Two of the plants have a second deinking operation after dispersion. The plants have a significant water exchange based on thickening to over 30% and then diluting with paper machine white water and sulfuric acid. Most of the brightness increase occurs during the deinking step which usually includes some hydrogen peroxide. Bleaching chemicals may also be added after the final water exchange and before pulp storage. The final deinked pulp has proven to be very good for producing newsprint on modern new machine where the deinked pulp represents 30% to 50% of the furnish.