Waste printed paper colour removal process

摘要

In a new process for printing ink etc removal from wastepaper a rapid flotation step is inserted between hydromechanical separation and washing stages. In the rapid flotation the 3-15% suspension is diluted to 0.05%-1 pref. 0.2-0.8wt% and undergoes flotation for less than 300 secs. pref 40-120 secs. with decolouring composition according to IT Pat. Appln. 28816A/77 and 27242A/78) The dilute suspension is transferred to the washing stages. Printing ink of hight and medium particle size is removed with low magent usage and removal of thermoplastic and sticky material. (Provisional basic previously advised in week E32)