Pulping cellulose-containing materials

DTEXTILES PAPER D21Papermaking D21CPRODUCTION OF CELLULOSE BY REMOVING NON-CELLULOSE SUBSTANCES FROM CELLULOSE-CONTAINING MATERIALS REGENERATION OF PULPING LIQUORS APPARATUS THEREFOR

D21C3/00Pulping cellulose-containing materials

D21C3/003with organic compounds D21C3/006with compounds not otherwise provided for D21C3/02with inorganic bases or alkaline reacting compounds D21C3/022in presence of S-containing compounds D21C3/024with NH3 or H2O D21C3/026in presence of O2 D21C3/028in presence of O3 D21C3/04with acids, acid salts or acid anhydrides D21C3/045in presence of O2 or O3 D21C3/06sulfur dioxide sulfurous acid bisulfites sulfites D21C3/08calcium bisulfite D21C3/10magnesium bisulfite D21C3/12sodium bisulfite D21C3/14ammonium bisulfite D21C3/16nitrogen oxides nitric acid nitrates, nitrites D21C3/18with halogens or halogen-generating compounds D21C3/20with organic solvents or in solvent environment D21C3/22Other features of pulping processes D21C3/222Use of compounds accelerating the pulping processes D21C3/224Use of means other than pressure and temperature D21C3/226Use of compounds avoiding scale formation D21C3/228Automation of the pulping processes D21C3/24Continuous processes D21C3/26Multistage processes D21C3/263at least one stage being in presence of oxygen D21C3/266the same pulping agent being used in all stages D21C3/28Prevention of foam