D21C1/00	7	Pretreatment of the finely-divided materials before digesting (of waste paper D21C5/02)	D21C1/00	D21C1/00		536
D21C1/02	8	with water or steam	D21C1/02	D21C1/02		595
D21C1/04	8	with acid reacting compounds	D21C1/04	D21C1/04		383
D21C1/06	8	with alkaline reacting compounds	D21C1/06	D21C1/06		505
D21C1/08	8	with oxygen-generating compounds	D21C1/08	D21C1/08		47
D21C1/10	8	Physical methods for facilitating impregnation	D21C1/10	D21C1/10		208
D21C3/00	7	Pulping cellulose-containing materials (digesters D21C7/00)	D21C3/00	D21C3/00		315
D21C3/003	8	{with organic compounds (D21C3/20 and D21C3/222 take precedence)}	D21C3/00	D21C3/00		341
D21C3/006	8	{with compounds not otherwise provided for}	D21C3/00	D21C3/00		182
D21C3/02	8	with inorganic bases or alkaline reacting compounds, e.g. sulfate processes	D21C3/02	D21C3/02		1191
D21C3/022	9	{in presence of S-containing compounds}	D21C3/02	D21C3/02		337
D21C3/024	9	{with NH3 or H2O}	D21C3/02	D21C3/02		58
D21C3/026	9	{in presence of O2, e.g. air}	D21C3/02	D21C3/02		88
D21C3/028	9	{in presence of O3}	D21C3/02	D21C3/02		10
D21C3/04	8	with acids, acid salts or acid anhydrides {(D21C3/003 and D21C3/222 take precedence)}	D21C3/04	D21C3/04		437
D21C3/045	9	{in presence of O2 or O3}	D21C3/04	D21C3/04		15
D21C3/06	9	sulfur dioxide; sulfurous acid; bisulfites {sulfites}	D21C3/06	D21C3/06		348
D21C3/08	10	calcium bisulfite	D21C3/08	D21C3/08		14
D21C3/10	10	magnesium bisulfite	D21C3/10	D21C3/10		29
D21C3/12	10	sodium bisulfite	D21C3/12	D21C3/12		30
D21C3/14	10	ammonium bisulfite	D21C3/14	D21C3/14		23
D21C3/16	9	nitrogen oxides; nitric acid {nitrates, nitrites}	D21C3/16	D21C3/16		91
D21C3/18	8	with halogens or halogen-generating compounds (bleaching cellulose pulp D21C9/12)	D21C3/18	D21C3/18		116
D21C3/20	8	with organic solvents {or in solvent environment}	D21C3/20	D21C3/20		494
D21C3/22	8	Other features of pulping processes	D21C3/22	D21C3/22		609
D21C3/222	9	{Use of compounds accelerating the pulping processes}	D21C3/22	D21C3/22		537
D21C3/224	9	{Use of means other than pressure and temperature}	D21C3/22	D21C3/22		114
D21C3/226	9	{Use of compounds avoiding scale formation}	D21C3/22	D21C3/22		44
D21C3/228	9	{Automation of the pulping processes}	D21C3/22	D21C3/22		93
D21C3/24	9	Continuous processes	D21C3/24	D21C3/24		348
D21C3/26	9	Multistage processes	D21C3/26	D21C3/26		397
D21C3/263	10	{at least one stage being in presence of oxygen}	D21C3/26	D21C3/26		47
D21C3/266	10	{the same pulping agent being used in all stages (D21C3/263 takes precedence)}	D21C3/26	D21C3/26		88
D21C3/28	9	Prevention of foam	D21C3/28	D21C3/28		80
D21C5/00	7	Other processes for obtaining cellulose, e.g. cooking cotton linters (obtaining fibres for spinning D01C); {Processes characterised by the choice of cellulose-containing starting materials}	D21C5/00	D21C5/00		1786
D21C5/005	8	{Treatment of cellulose-containing material with microorganisms or enzymes}	D21C5/00	D21C5/00		1744
D21C5/02	8	Working-up waste paper (mechanical part D21B1/08, D21B1/32)	D21C5/02	D21C5/02		1195
D21C5/022	9	{Chemicals therefor}	D21C5/02	D21C5/02		243
D21C5/025	9	{De-inking}	D21C5/02	D21C5/02		419
D21C5/027	10	{Chemicals therefor}	D21C5/02	D21C5/02		546
D21C7/00	7	Digesters	D21C7/00	D21C7/00		775
D21C7/02	8	Rotary digesters	D21C7/02	D21C7/02		68
D21C7/04	8	Linings	D21C7/04	D21C7/04		30
D21C7/06	8	Feeding devices	D21C7/06	D21C7/06		453
D21C7/08	8	Discharge devices	D21C7/08	D21C7/08		245
D21C7/10	8	Heating devices	D21C7/10	D21C7/10		139
D21C7/12	8	Devices for regulating or controlling	D21C7/12	D21C7/12		230
D21C7/14	8	Means for circulating the lye	D21C7/14	D21C7/14		302
D21C7/16	8	Safety devices	D21C7/16	D21C7/16		21
D21C9/00	7	After-treatment of cellulose pulp, e.g. of wood pulp, or cotton linters {; Treatment of dilute or dewatered pulp or process improvement taking place after obtaining the raw cellulosic material and not provided for elsewhere (polysaccharides, derivatives thereof C08B; paper-making D21B&#160;-&#160;D21H)}	D21C9/00	D21C9/00		358
D21C9/001	8	{Modification of pulp properties (purification D21C9/08)}	D21C9/00	D21C9/00		196
D21C9/002	9	{by chemical means; preparation of dewatered pulp, e.g. in sheet or bulk form, containing special additives}	D21C9/00	D21C9/00		374
D21C9/004	10	{inorganic compounds}	D21C9/00	D21C9/00		418
D21C9/005	10	{organic compounds}	D21C9/00	D21C9/00		521
D21C9/007	9	{by mechanical or physical means}	D21C9/00	D21C9/00		610
D21C9/008	8	{Prevention of corrosion or formation of deposits on pulp-treating equipment (D21C9/08, D21H21/02 take precedence)}	D21C9/00	D21C9/00		139
D21C9/02	8	Washing {; Displacing cooking or pulp-treating liquors contained in the pulp by fluids, e.g. wash water or other pulp-treating agents}	D21C9/02	D21C9/02		752
D21C9/04	9	in diffusers {; Washing of pulp of fluid consistency without substantially thickening}	D21C9/04	D21C9/04		91
D21C9/06	9	in filters {; Washing of concentrated pulp, e.g. pulp mats, on filtering surfaces}	D21C9/06	D21C9/06		383
D21C9/08	8	Removal of fats, resins, pitch or waxes; {Chemical or physical purification, i.e. refining, of crude cellulose by removing non-cellulosic contaminants, optionally combined with bleaching (fats, waxes C11B; natural resins C09F1/00; hemicellulose C08B37/14; purification by mechanical means D21D5/00)}	D21C9/08	D21C9/08		327
D21C9/083	9	{with inorganic compounds (D21C9/086 takes precedence)}	D21C9/08	D21C9/08		185
D21C9/086	9	{with organic compounds or compositions comprising organic compounds}	D21C9/08	D21C9/08		169
D21C9/10	8	Bleaching {; Apparatus therefor}	D21C9/10	D21C9/10		950
D21C9/1005	9	{Pretreatment of the pulp, e.g. degassing the pulp}	D21C9/10	D21C9/10		218
D21C9/101	9	{in solvent medium}	D21C9/10	D21C9/10		20
D21C9/1015	9	{with use of means other than pressure, temperature}	D21C9/10	D21C9/10		24
D21C9/1021	9	{Electrochemical processes}	D21C9/10	D21C9/10		24
D21C9/1026	9	{Other features in bleaching processes}	D21C9/10	D21C9/10		337
D21C9/1031	10	{Pulse, dynamic, displacement processes}	D21C9/10	D21C9/10		28
D21C9/1036	10	{Use of compounds accelerating or improving the efficiency of the processes}	D21C9/10	D21C9/10		426
D21C9/1042	10	{Use of chelating agents}	D21C9/10	D21C9/10		282
D21C9/1047	10	{Conserving the bleached pulp}	D21C9/10	D21C9/10		46
D21C9/1052	10	{Controlling the process}	D21C9/10	D21C9/10		88
D21C9/1057	9	{Multistage, with compounds cited in more than one sub-group D21C9/10, D21C9/12, D21C9/16}	D21C9/10	D21C9/10		333
D21C9/1063	9	{with compounds not otherwise provided for, e.g. activated gases}	D21C9/10	D21C9/10		95
D21C9/1068	9	{with O2(closed, seeD21C9/147)}	D21C9/10	D21C9/10		74
D21C9/1073	9	{with O3(closed, seeD21C9/153)}	D21C9/10	D21C9/10		48
D21C9/1078	9	{with Mn-containing compounds}	D21C9/10	D21C9/10		12
D21C9/1084	9	{with reducing compounds}	D21C9/10	D21C9/10		110
D21C9/1089	10	{with dithionites}	D21C9/10	D21C9/10		49
D21C9/1094	10	{with H2}	D21C9/10	D21C9/10		2
D21C9/12	9	with halogens or halogen-containing compounds (D21C9/16 takes precedence)	D21C9/12	D21C9/12		215
D21C9/123	10	{with Cl2O}	D21C9/12	D21C9/12		34
D21C9/126	10	{with perhalogeno compounds}	D21C9/12	D21C9/12		1
D21C9/14	10	with ClO2 or chlorites	D21C9/14	D21C9/14		308
D21C9/142	11	{with ClO2/Cl2 in a multistage process involving ClO2/Cl2 exclusively}	D21C9/14	D21C9/14		69
D21C9/144	11	{with ClO2/Cl2 and other bleaching agents in a multistage process}	D21C9/14	D21C9/14		176
D21C9/147	9	with oxygen or its allotropic modifications (D21C9/16 takes precedence)	D21C9/147	D21C9/147		363
D21C9/153	10	with ozone	D21C9/153	D21C9/153		327
D21C9/16	9	with per compounds	D21C9/16	D21C9/16		210
D21C9/163	10	{with peroxides}	D21C9/16	D21C9/16		840
D21C9/166	10	{with peracids}	D21C9/16	D21C9/16		97
D21C9/18	8	De-watering (de-watering in general F26B); {Elimination of cooking or pulp-treating liquors from the pulp}(D21C9/002, D21C9/02 take precedence; paper-making machines D21F; strainers in digesters D21C7/00; presses in general B30B)	D21C9/18	D21C9/18		881
D21C9/185	9	{comprising at least one step where the pulp is suspended in a gaseous medium, e.g. flash drying}	D21C9/18	D21C9/18		57
D21C11/00	7	Regeneration of pulp liquors {or effluent waste waters}	D21C11/00	D21C11/00		337
D21C11/0007	8	{Recovery of by-products, i.e. compounds other than those necessary for pulping, for multiple uses or not otherwise provided for (volatile compounds obtained by decomposition of spent liquors in order to regenerate them D21C11/125; compounds obtained by fractionating the liquors in order to regenerate them D21C11/0042)}	D21C11/00	D21C11/00		954
D21C11/0014	8	{Combination of various pulping processes with one or several recovery systems (cross-recovery)}	D21C11/00	D21C11/00		92
D21C11/0021	8	{Introduction of various effluents, e.g. waste waters, into the pulping, recovery and regeneration cycle (closed-cycle)}	D21C11/00	D21C11/00		146
D21C11/0028	9	{Effluents derived from the washing or bleaching plants}	D21C11/00	D21C11/00		148
D21C11/0035	8	{Introduction of compounds, e.g. sodium sulfate, into the cycle in order to compensate for the losses of pulping agents}	D21C11/00	D21C11/00		51
D21C11/0042	8	{Fractionating or concentration of spent liquors by special methods (concentration by evaporation D21C11/10)}	D21C11/00	D21C11/00		198
D21C11/005	9	{Treatment of liquors with ion-exchangers}	D21C11/00	D21C11/00		48
D21C11/0057	8	{Oxidation of liquors, e.g. in order to reduce the losses of sulfur compounds, followed by evaporation or combustion if the liquor in question is a black liquor (deodorisation of gases D21C11/08; combustion D21C11/12, D21C11/14)}	D21C11/00	D21C11/00		166
D21C11/0064	8	{Aspects concerning the production and the treatment of green and white liquors, e.g. causticizing green liquor}	D21C11/00	D21C11/00		193
D21C11/0071	9	{Treatment of green or white liquors with gases, e.g. with carbon dioxide for carbonation; Expulsion of gaseous compounds, e.g. hydrogen sulfide, from these liquors by this treatment (stripping); Optional separation of solid compounds formed in the liquors by this treatment (oxidation of liquors (black, green or white) D21C11/0057; treatment of pulp gases D21C11/06)}	D21C11/00	D21C11/00		106
D21C11/0078	9	{Treatment of green or white liquors with other means or other compounds than gases, e.g. in order to separate solid compounds such as sodium chloride and carbonate from these liquors; Further treatment of these compounds (fractionating of spent liquors D21C11/0042)}	D21C11/00	D21C11/00		120
D21C11/0085	8	{Introduction of auxiliary substances into the regenerating system in order to improve the performance of certain steps of the latter, the presence of these substances being confined to the regeneration cycle (introduction of compounds in order to make up for the losses of pulping agents D21C11/0035; conventional causticizing of green liquors D21C11/0064; fractionating of spent liquors D21C11/0042)}	D21C11/00	D21C11/00		87
D21C11/0092	9	{Substances modifying the evaporation, combustion, or thermal decomposition processes of black liquor (treatment of solid substances (ash) separated from combustion gases D21C11/066; avoiding scale-forming during evaporation D21C11/106)}	D21C11/00	D21C11/00		69
D21C11/02	8	of {acid, neutral or alkaline} sulfite lye	D21C11/02	D21C11/02		184
D21C11/04	8	of alkali lye	D21C11/04	D21C11/04		396
D21C11/06	8	Treatment of pulp gases; Recovery of the heat content of the gases; {Treatment of gases arising from various sources in pulp and paper mills; Regeneration of gaseous SO2, e.g. arising from liquors containing sulfur compounds}	D21C11/06	D21C11/06		382
D21C11/063	9	{Treatment of gas streams comprising solid matter, e.g. the ashes resulting from the combustion of black liquor (evaporation of pulp liquors by direct contact with gases D21C11/103; post-combustion of gases D21C11/127)}	D21C11/06	D21C11/06		85
D21C11/066	10	{Separation of solid compounds from these gases; further treatment of recovered products}	D21C11/06	D21C11/06		91
D21C11/08	9	Deodorisation {; Elimination of malodorous compounds, e.g. sulfur compounds such as hydrogen sulfide or mercaptans, from gas streams (oxidation of liquors D21C11/0057; post-combustion of gases D21C11/127)}	D21C11/08	D21C11/08		94
D21C11/10	8	Concentrating spent liquor by evaporation (evaporators B01D)	D21C11/10	D21C11/10		246
D21C11/103	9	{Evaporation by direct contact with gases, e.g. hot flue gases}	D21C11/10	D21C11/10		68
D21C11/106	9	{Prevention of incrustations on heating surfaces during the concentration, e.g. by elimination of the scale-forming substances contained in the liquors}	D21C11/10	D21C11/10		73
D21C11/12	8	Combustion of pulp liquors	D21C11/12	D21C11/12		496
D21C11/122	9	{Treatment, e.g. dissolution, of the smelt}	D21C11/12	D21C11/12		115
D21C11/125	9	{Decomposition of the pulp liquors in reducing atmosphere or in the absence of oxidants, i.e. gasification or pyrolysis}	D21C11/12	D21C11/12		173
D21C11/127	10	{with post-combustion of the gases}	D21C11/12	D21C11/12		33
D21C11/14	9	Wet combustion {; Treatment of pulp liquors without previous evaporation, by oxidation of the liquors remaining at least partially in the liquid phase, e.g. by application or pressure (oxidation of black, green or white liquors D21C11/0057)}	D21C11/14	D21C11/14		50
