Method and device for the flotation of suspensions

摘要

In a process to recycle waste paper, ink or dye is removed from a de-inked pulp suspension in series of floatation stages, each esp. separated from the next by a washing stage. An Independent claim is also included for a commensurate assembly in which the washing process is part of a closed liquid recycling stage and takes place between a primary and secondary cell. Prior to its admission to the secondary cell, the suspension is diluted to 0.6 to 1.4 % dry matter by density. In a preferred embodiment, the washed product from two washing cells is blended and subjected to a further washing stage.