Method and apparatus for preparing stock containing ash from waste paper

摘要

A method of preparing an aqueous fibrous suspension containing a desired amount of ash particles from waste paper comprises preparing an aqueous fibrous suspension comprising ash particles from waste paper, optionally after passage through cleaning plant 1 and screening equipment 2, feeding said suspension to a filter 3, which may be a twin-wire machine operating at 300-1000m/min, passing the filtrate therefrom via line 5 to a sedimentation and/or flotation appliance 4 to substantially separate ash particles therefrom, and returning the latter via lines 7, 14 in a regulated amount to the filtered fibrous suspension in line 15 prior to further filtration e.g. on band-pass filter 16.