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Publication of BE452026ApublicationCriticalpatent/BE452026A/xx
D21C—PRODUCTION OF CELLULOSE BY REMOVING NON-CELLULOSE SUBSTANCES FROM CELLULOSE-CONTAINING MATERIALS; REGENERATION OF PULPING LIQUORS; APPARATUS THEREFOR
D21C3/00—Pulping cellulose-containing materials
D21C3/22—Other features of pulping processes
D21C3/26—Multistage processes
D21C3/266—Multistage processes the same pulping agent being used in all stages
D—TEXTILES; PAPER
D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
D21C—PRODUCTION OF CELLULOSE BY REMOVING NON-CELLULOSE SUBSTANCES FROM CELLULOSE-CONTAINING MATERIALS; REGENERATION OF PULPING LIQUORS; APPARATUS THEREFOR
D21C3/00—Pulping cellulose-containing materials
D21C3/04—Pulping cellulose-containing materials with acids, acid salts or acid anhydrides
D21C3/06—Pulping cellulose-containing materials with acids, acid salts or acid anhydrides sulfur dioxide; sulfurous acid; bisulfites sulfites
D—TEXTILES; PAPER
D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
D21C—PRODUCTION OF CELLULOSE BY REMOVING NON-CELLULOSE SUBSTANCES FROM CELLULOSE-CONTAINING MATERIALS; REGENERATION OF PULPING LIQUORS; APPARATUS THEREFOR
