METHOD AND EQUIPMENT FOR SEPARATING PAPER FIBER AND PLASTIC FROM MIXED WASTE MATERIAL

摘要

PURPOSE: To obtain substantially pure paper fibers by agitating mixed waste materials containing paper and plastics in the presence of water to form a slurry, separating the paper fiber portion from the slurry, concentrating the separated paper fiber portion and then removing contaminants. CONSTITUTION: This method of separating paper fibers from mixed waste materials which contain paper fibers, plastics, and sometimes further metals comprises agitating the mixed waste materials in the presence of water in a hydrapulper to form a slurry comprised of a paper-fiber portion and a plastic portion, passing the slurry through a liquid cyclone 13, a coarse screen 9 and a slotted screen 10 to produce a paper fiber-enriched stream 14, transporting the paper fiber-enriched stream 14 from the slotted screen 10 to a portion of the separation system 16 which includes first and second centrifugal separators 18, 20, transporting the contaminant-removed paper fiber-enriched stream 28 to a flotation tank 30 to separate ink particles, washing the paper fiber-enriched stream with water, thickening the paper fiber stream in a thickener 36, treating the paper fiber stream in a disperger 38 to reduce the size of the ink particles which are then broken down into very small pieces, removing the light contaminants from the deinked fiber-enriched stream, and then pressing the fiber-enriched stream to remove a substantial amount of water.