ABSTRACT
Wastepaper is recycled as pulp for reproduction of papers or boards. The pulp containing secondary fibers needs to be purified in a deinking installation. A total closed water system has now been developed for water reclamation in deinking installations. For decades two principal deinking systems have been competing. Flotation deinking, extracting ink by foam generated by a dispersed air flotation cell mineral filler and paper fines are mainly recovered therefore the yield is high but the physical strength of the deinked stock is poor. Washing deinking where ink, mineral filler and fiber fines are washed out at high dilution and a papermaking fiber of good quality is obtained with sacrifice of lower yield. Total closing of a 98-TPD paper mill with deinking and clarification installations made possible by the use of two dissolved air flotation (DAF) cells and a flotation-filtration clarifier (Sandfloat). The wastewater is clarified by a dissolved air flotation cell Supracell for water reclamation.
