| 摘要 |
<p>1476577 Purifying waste water AKZO NV 8 July 1975 [10 July 1974] 28752/75 Heading B1D [Also in Division C1] Solids are separated from waste water in a paper making process, which process uses a raw material comprising printed waste paper, wherein a flocculation step (e.g. using Al 2 (SO 4 ) 3 ), followed by a separation of flocculate from the water, is followed by the addition to the water of a filter aid consisting of material mechanically removed from paper pulp prior to the paper forming process, and separating from the water solid waste material. In flow diagram (Fig. 1) waste paper and water are mixed at A, passed to a pulp purifier B (e.g. a cyclone) from which heavy constituents flow along path 5. After a papermaking stage C and sedimentation apparatus D, flocculate is screened at E to remove usable fibres (which are recycled along path 11). The liquid is then mixed with the heavy constituents (added solid material) from path 5 and filtered or centrifuged at F, compacted at G and dumped or incinerated.</p> |
