METODO PER IL RECUPERO DI IDROSSIDO DI SODIO DAL LIQUIDA DI SCARICO DA OPERAZIONI DI RIDUZIONE IN PASTA O DI IMBIANCHIMENTO NELL INDUSTRIA DELLA CARTA

摘要

1454660 Regeneration of sodium hydroxide TOYO PULP CO Ltd 7 Oct 1974 [23 Feb 1974] 43350/74 Heading C1A Sodium hydroxide is recovered from waste liquors from pulping/bleaching cellulosic materials by roasting ferric oxide with the concentrated liquor and immersing the resulting mix in water thus regenerating NaOH and precipitating Fe 2 O 3 which is re-used for further reclamation. Roasting is preferably undertaken at from 700‹ to 900‹ C. with the smelted mix being immersed in water preferably maintained at 50‹ to 100‹ C.