CA1133660A - Process for the preparation of cellulose fibres from pine - Google Patents

Process for the preparation of cellulose fibres from pine

Info

Publication number: CA1133660A
Authority: CA; Canada
Prior art keywords: weight; peroxide; pine; cellulose fibres; fibre
Prior art date: 1977-09-20
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.): Expired

Application number

CA311,653A

Other languages

English (en)

French (fr)

Inventor

Horst Kruger

Werner Traser

Johann-Peter Franzreb

Heinrich Klein

Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)

SCHWABISCHE ZELLSTOFF AG

Evonik Operations GmbH

Original Assignee

SCHWABISCHE ZELLSTOFF AG

Degussa GmbH

Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)

1977-09-20

Filing date

1978-09-20

Publication date

1982-10-19

1978-09-20 Application filed by SCHWABISCHE ZELLSTOFF AG, Degussa GmbH filed Critical SCHWABISCHE ZELLSTOFF AG

1982-10-19 Application granted granted Critical

1982-10-19 Publication of CA1133660A publication Critical patent/CA1133660A/en

Status Expired legal-status Critical Current

Links

238000000034 method Methods 0.000 title claims abstract description 71
230000008569 process Effects 0.000 title claims abstract description 46
229920003043 Cellulose fiber Polymers 0.000 title claims abstract description 42
235000008331 Pinus X rigitaeda Nutrition 0.000 title claims abstract description 34
235000011613 Pinus brutia Nutrition 0.000 title claims abstract description 34
241000018646 Pinus brutia Species 0.000 title claims abstract description 34
238000002360 preparation method Methods 0.000 title claims abstract description 9
ZAMOUSCENKQFHK-UHFFFAOYSA-N Chlorine atom Chemical compound [Cl] ZAMOUSCENKQFHK-UHFFFAOYSA-N 0.000 claims abstract description 25
239000000460 chlorine Substances 0.000 claims abstract description 25
229910052801 chlorine Inorganic materials 0.000 claims abstract description 25
LSNNMFCWUKXFEE-UHFFFAOYSA-L sulfite Chemical compound [O-]S([O-])=O LSNNMFCWUKXFEE-UHFFFAOYSA-L 0.000 claims abstract description 15
239000003513 alkali Substances 0.000 claims abstract description 13
238000011282 treatment Methods 0.000 claims abstract description 13
239000012736 aqueous medium Substances 0.000 claims abstract description 9
238000004061 bleaching Methods 0.000 claims abstract description 9
239000002609 medium Substances 0.000 claims abstract description 7
-1 per-oxide compounds Chemical class 0.000 claims abstract description 7
238000004537 pulping Methods 0.000 claims abstract description 6
230000002378 acidificating effect Effects 0.000 claims abstract description 5
239000000835 fiber Substances 0.000 claims description 35
150000002978 peroxides Chemical class 0.000 claims description 18
239000001913 cellulose Substances 0.000 claims description 12
239000000463 material Substances 0.000 claims description 9
MHAJPDPJQMAIIY-UHFFFAOYSA-N Hydrogen peroxide Chemical group OO MHAJPDPJQMAIIY-UHFFFAOYSA-N 0.000 claims description 6
TWRXJAOTZQYOKJ-UHFFFAOYSA-L Magnesium chloride Chemical group [Mg+2].[Cl-].[Cl-] TWRXJAOTZQYOKJ-UHFFFAOYSA-L 0.000 claims description 6
238000007670 refining Methods 0.000 claims description 6
239000002253 acid Substances 0.000 claims description 5
238000009835 boiling Methods 0.000 claims description 5
235000010980 cellulose Nutrition 0.000 claims description 5
159000000003 magnesium salts Chemical class 0.000 claims description 5
VHUUQVKOLVNVRT-UHFFFAOYSA-N Ammonium hydroxide Chemical compound [NH4+].[OH-] VHUUQVKOLVNVRT-UHFFFAOYSA-N 0.000 claims description 3
229910001860 alkaline earth metal hydroxide Inorganic materials 0.000 claims description 3
229940106135 cellulose Drugs 0.000 claims description 3
229910001629 magnesium chloride Inorganic materials 0.000 claims description 3
239000000725 suspension Substances 0.000 claims description 3
AXZKOIWUVFPNLO-UHFFFAOYSA-N magnesium;oxygen(2-) Chemical class [O-2].[Mg+2] AXZKOIWUVFPNLO-UHFFFAOYSA-N 0.000 claims description 2
PFUVRDFDKPNGAV-UHFFFAOYSA-N sodium peroxide Chemical compound [Na+].[Na+].[O-][O-] PFUVRDFDKPNGAV-UHFFFAOYSA-N 0.000 claims description 2
229910052783 alkali metal Inorganic materials 0.000 claims 2
150000001340 alkali metals Chemical class 0.000 claims 2
238000009874 alkali refining Methods 0.000 claims 2
239000000908 ammonium hydroxide Substances 0.000 claims 2
229940053326 magnesium salt Drugs 0.000 claims 2
QTBSBXVTEAMEQO-UHFFFAOYSA-M Acetate Chemical compound CC([O-])=O QTBSBXVTEAMEQO-UHFFFAOYSA-M 0.000 claims 1
CPELXLSAUQHCOX-UHFFFAOYSA-M Bromide Chemical compound [Br-] CPELXLSAUQHCOX-UHFFFAOYSA-M 0.000 claims 1
BPQQTUXANYXVAA-UHFFFAOYSA-N Orthosilicate Chemical compound [O-][Si]([O-])([O-])[O-] BPQQTUXANYXVAA-UHFFFAOYSA-N 0.000 claims 1
QAOWNCQODCNURD-UHFFFAOYSA-L Sulfate Chemical compound [O-]S([O-])(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-L 0.000 claims 1
239000000654 additive Substances 0.000 claims 1
230000000996 additive effect Effects 0.000 claims 1
XMBWDFGMSWQBCA-UHFFFAOYSA-N hydrogen iodide Chemical compound I XMBWDFGMSWQBCA-UHFFFAOYSA-N 0.000 claims 1
229910021653 sulphate ion Inorganic materials 0.000 claims 1
HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 description 15
YMWUJEATGCHHMB-UHFFFAOYSA-N Dichloromethane Chemical compound ClCCl YMWUJEATGCHHMB-UHFFFAOYSA-N 0.000 description 10
229920002678 cellulose Polymers 0.000 description 10
CPLXHLVBOLITMK-UHFFFAOYSA-N magnesium oxide Inorganic materials [Mg]=O CPLXHLVBOLITMK-UHFFFAOYSA-N 0.000 description 9
239000012632 extractable Substances 0.000 description 6
239000000395 magnesium oxide Substances 0.000 description 5
235000012245 magnesium oxide Nutrition 0.000 description 5
239000002351 wastewater Substances 0.000 description 5
VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 description 4
238000006887 Ullmann reaction Methods 0.000 description 4
239000007864 aqueous solution Substances 0.000 description 4
239000007844 bleaching agent Substances 0.000 description 4
OSVXSBDYLRYLIG-UHFFFAOYSA-N dioxidochlorine(.) Chemical compound O=Cl=O OSVXSBDYLRYLIG-UHFFFAOYSA-N 0.000 description 4
QTBSBXVTEAMEQO-UHFFFAOYSA-N Acetic acid Chemical compound CC(O)=O QTBSBXVTEAMEQO-UHFFFAOYSA-N 0.000 description 3
KWYUFKZDYYNOTN-UHFFFAOYSA-M Potassium hydroxide Chemical compound [OH-].[K+] KWYUFKZDYYNOTN-UHFFFAOYSA-M 0.000 description 3
238000004519 manufacturing process Methods 0.000 description 3
VEXZGXHMUGYJMC-UHFFFAOYSA-M Chloride anion Chemical compound [Cl-] VEXZGXHMUGYJMC-UHFFFAOYSA-M 0.000 description 2
239000004155 Chlorine dioxide Substances 0.000 description 2
CSNNHWWHGAXBCP-UHFFFAOYSA-L Magnesium sulfate Chemical compound [Mg+2].[O-][S+2]([O-])([O-])[O-] CSNNHWWHGAXBCP-UHFFFAOYSA-L 0.000 description 2
QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 description 2
235000010260 calcium hydrogen sulphite Nutrition 0.000 description 2
235000019398 chlorine dioxide Nutrition 0.000 description 2
238000010411 cooking Methods 0.000 description 2
239000002657 fibrous material Substances 0.000 description 2
WQYVRQLZKVEZGA-UHFFFAOYSA-N hypochlorite Chemical compound Cl[O-] WQYVRQLZKVEZGA-UHFFFAOYSA-N 0.000 description 2
BDAGIHXWWSANSR-UHFFFAOYSA-N methanoic acid Natural products OC=O BDAGIHXWWSANSR-UHFFFAOYSA-N 0.000 description 2
150000007522 mineralic acids Chemical class 0.000 description 2
239000003381 stabilizer Substances 0.000 description 2
239000007858 starting material Substances 0.000 description 2
239000001117 sulphuric acid Substances 0.000 description 2
235000011149 sulphuric acid Nutrition 0.000 description 2
239000002023 wood Substances 0.000 description 2
OSWFIVFLDKOXQC-UHFFFAOYSA-N 4-(3-methoxyphenyl)aniline Chemical compound COC1=CC=CC(C=2C=CC(N)=CC=2)=C1 OSWFIVFLDKOXQC-UHFFFAOYSA-N 0.000 description 1
NLXLAEXVIDQMFP-UHFFFAOYSA-N Ammonium chloride Substances [NH4+].[Cl-] NLXLAEXVIDQMFP-UHFFFAOYSA-N 0.000 description 1
KZBUYRJDOAKODT-UHFFFAOYSA-N Chlorine Chemical compound ClCl KZBUYRJDOAKODT-UHFFFAOYSA-N 0.000 description 1
RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 1
MJZZHTJUILGXLJ-UHFFFAOYSA-N [Cu].ClCCl Chemical compound [Cu].ClCCl MJZZHTJUILGXLJ-UHFFFAOYSA-N 0.000 description 1
150000007513 acids Chemical class 0.000 description 1
150000008044 alkali metal hydroxides Chemical class 0.000 description 1
QGZKDVFQNNGYKY-UHFFFAOYSA-N ammonia Natural products N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 description 1
235000011114 ammonium hydroxide Nutrition 0.000 description 1
230000015572 biosynthetic process Effects 0.000 description 1
LVGQIQHJMRUCRM-UHFFFAOYSA-L calcium bisulfite Chemical compound [Ca+2].OS([O-])=O.OS([O-])=O LVGQIQHJMRUCRM-UHFFFAOYSA-L 0.000 description 1
AXCZMVOFGPJBDE-UHFFFAOYSA-L calcium dihydroxide Chemical compound [OH-].[OH-].[Ca+2] AXCZMVOFGPJBDE-UHFFFAOYSA-L 0.000 description 1
239000000920 calcium hydroxide Substances 0.000 description 1
229910001861 calcium hydroxide Inorganic materials 0.000 description 1
229920003086 cellulose ether Polymers 0.000 description 1
238000006243 chemical reaction Methods 0.000 description 1
150000001875 compounds Chemical class 0.000 description 1
229910052802 copper Inorganic materials 0.000 description 1
239000010949 copper Substances 0.000 description 1
238000007730 finishing process Methods 0.000 description 1
235000019253 formic acid Nutrition 0.000 description 1
229910001504 inorganic chloride Inorganic materials 0.000 description 1
229920005610 lignin Polymers 0.000 description 1
UEGPKNKPLBYCNK-UHFFFAOYSA-L magnesium acetate Chemical compound [Mg+2].CC([O-])=O.CC([O-])=O UEGPKNKPLBYCNK-UHFFFAOYSA-L 0.000 description 1
239000011654 magnesium acetate Substances 0.000 description 1
235000011285 magnesium acetate Nutrition 0.000 description 1
229940069446 magnesium acetate Drugs 0.000 description 1
OTCKOJUMXQWKQG-UHFFFAOYSA-L magnesium bromide Chemical compound [Mg+2].[Br-].[Br-] OTCKOJUMXQWKQG-UHFFFAOYSA-L 0.000 description 1
229910001623 magnesium bromide Inorganic materials 0.000 description 1
ZLNQQNXFFQJAID-UHFFFAOYSA-L magnesium carbonate Chemical compound [Mg+2].[O-]C([O-])=O ZLNQQNXFFQJAID-UHFFFAOYSA-L 0.000 description 1
239000001095 magnesium carbonate Substances 0.000 description 1
229910000021 magnesium carbonate Inorganic materials 0.000 description 1
VTHJTEIRLNZDEV-UHFFFAOYSA-L magnesium dihydroxide Chemical compound [OH-].[OH-].[Mg+2] VTHJTEIRLNZDEV-UHFFFAOYSA-L 0.000 description 1
239000000347 magnesium hydroxide Substances 0.000 description 1
229910001862 magnesium hydroxide Inorganic materials 0.000 description 1
BLQJIBCZHWBKSL-UHFFFAOYSA-L magnesium iodide Chemical compound [Mg+2].[I-].[I-] BLQJIBCZHWBKSL-UHFFFAOYSA-L 0.000 description 1
229910001641 magnesium iodide Inorganic materials 0.000 description 1
HCWCAKKEBCNQJP-UHFFFAOYSA-N magnesium orthosilicate Chemical compound [Mg+2].[Mg+2].[O-][Si]([O-])([O-])[O-] HCWCAKKEBCNQJP-UHFFFAOYSA-N 0.000 description 1
239000000391 magnesium silicate Substances 0.000 description 1
229910052919 magnesium silicate Inorganic materials 0.000 description 1
235000019792 magnesium silicate Nutrition 0.000 description 1
229910052943 magnesium sulfate Inorganic materials 0.000 description 1
235000019341 magnesium sulphate Nutrition 0.000 description 1
MGFYIUFZLHCRTH-UHFFFAOYSA-N nitrilotriacetic acid Chemical compound OC(=O)CN(CC(O)=O)CC(O)=O MGFYIUFZLHCRTH-UHFFFAOYSA-N 0.000 description 1
150000004045 organic chlorine compounds Chemical class 0.000 description 1
150000001451 organic peroxides Chemical class 0.000 description 1
239000004033 plastic Substances 0.000 description 1
229920003023 plastic Polymers 0.000 description 1
235000019353 potassium silicate Nutrition 0.000 description 1
238000002203 pretreatment Methods 0.000 description 1
230000035484 reaction time Effects 0.000 description 1
230000009257 reactivity Effects 0.000 description 1
238000011069 regeneration method Methods 0.000 description 1
NTHWMYGWWRZVTN-UHFFFAOYSA-N sodium silicate Chemical compound [Na+].[Na+].[O-][Si]([O-])=O NTHWMYGWWRZVTN-UHFFFAOYSA-N 0.000 description 1
CIHOLLKRGTVIJN-UHFFFAOYSA-N tert‐butyl hydroperoxide Chemical compound CC(C)(C)OO CIHOLLKRGTVIJN-UHFFFAOYSA-N 0.000 description 1
238000004065 wastewater treatment Methods 0.000 description 1
XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1

Classifications

- 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
- D21C9/00—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
- D21C9/08—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

Landscapes

Life Sciences & Earth Sciences (AREA)
Engineering & Computer Science (AREA)
Wood Science & Technology (AREA)
Paper (AREA)
Polysaccharides And Polysaccharide Derivatives (AREA)
Cosmetics (AREA)
Sanitary Thin Papers (AREA)

CA311,653A 1977-09-20 1978-09-20 Process for the preparation of cellulose fibres from pine Expired CA1133660A (en)

Applications Claiming Priority (2)

Application Number	Priority Date	Filing Date	Title
DE2742262A DE2742262C2 (de)	1977-09-20	1977-09-20	Verfahren zur Herstellung eines mittel- bis hochviskosen Nadelholz-Sulfitzellstoffs
DEP2742262.4		1977-09-20

Publications (1)

Publication Number	Publication Date
CA1133660A true CA1133660A (en)	1982-10-19

Family

ID=6019413

Family Applications (1)

Application Number	Title	Priority Date	Filing Date
CA311,653A Expired CA1133660A (en)	1977-09-20	1978-09-20	Process for the preparation of cellulose fibres from pine

Country Status (16)

Country	Link
JP (1)	JPS5455606A (it)
AR (1)	AR218936A1 (it)
AT (1)	AT367812B (it)
BE (1)	BE870607A (it)
BR (1)	BR7806050A (it)
CA (1)	CA1133660A (it)
CH (1)	CH638003A5 (it)
DE (1)	DE2742262C2 (it)
ES (1)	ES472687A1 (it)
FI (1)	FI68273C (it)
FR (1)	FR2403418A1 (it)
GB (1)	GB2005743B (it)
IT (1)	IT1109111B (it)
NO (1)	NO153978C (it)
SE (1)	SE7809831L (it)
ZA (1)	ZA785356B (it)

Families Citing this family (13)

* Cited by examiner, † Cited by third party
Publication number	Priority date	Publication date	Assignee	Title
FR2520397A1 (fr) *	1982-01-28	1983-07-29	Centre Tech Ind Papier	Procede pour le traitement de pates papetieres chimiques
DE4031597A1 (de) *	1990-10-05	1992-04-09	Sueddeutsche Kalkstickstoff	Verfahren zur chlorarmen bleiche und delignifizierung von zellstoff
SE470065C (sv) *	1991-04-30	1996-01-15	Eka Nobel Ab	Behandling av kemisk massa med en syra och därefter en magnesium- och kalciumförening vid klorfri blekning
US6398908B1 (en)	1991-04-30	2002-06-04	Eka Nobel Ab	Process for acid bleaching of lignocellulose-containing pulp with a magnesium compound
ZA955290B (en) *	1994-07-11	1996-12-27	Ingersoll Rand Co	Peroxide bleaching process for cellulosic and lignocellulosic material
RU2128261C1 (ru) *	1998-05-26	1999-03-27	Сыктывкарский лесной институт Санкт-Петербургской лесотехнической академии	Способ отбелки целлюлозы
RU2142529C1 (ru) *	1999-05-17	1999-12-10	Сыктывкарский лесной институт Санкт-Петербургской лесотехнической академии	Способ отбелки целлюлозы
RU2164572C1 (ru) *	2000-03-14	2001-03-27	Сыктывкарский лесной институт Санкт-Петербургской лесотехнической академии	Способ отбелки сульфатной целлюлозы
RU2163946C1 (ru) *	2000-08-02	2001-03-10	Институт химии Коми научного центра Уральского отделения РАН	Способ отбелки материалов или полуфабрикатов, содержащих целлюлозу
RU2205257C1 (ru) *	2002-07-01	2003-05-27	Сыктывкарский лесной институт Санкт-Петербургской лесотехнической академии	Способ отбелки сульфатной целлюлозы
RU2243304C1 (ru) *	2004-02-04	2004-12-27	Томский политехнический университет	Способ безхлорной отбелки сульфатной целлюлозы
DE102007036376A1 (de) *	2007-07-31	2009-02-05	Voith Patent Gmbh	Gebleichter Faserstoff
RU2413046C1 (ru) *	2009-09-21	2011-02-27	Эльвира Ильинична Федорова	Способ отбелки сульфатной целлюлозы

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number	Priority date	Publication date	Assignee	Title
US2026068A (en) *	1929-09-11	1935-12-31	Du Pont	Process for the improvement of cellulose
DE753531C (de) *	1938-11-09	1953-05-18	Degussa	Verfahren zum Bleichen von Zellstoff

1977
- 1977-09-20 DE DE2742262A patent/DE2742262C2/de not_active Expired
1978
- 1978-08-18 NO NO782820A patent/NO153978C/no unknown
- 1978-08-18 ES ES472687A patent/ES472687A1/es not_active Expired
- 1978-08-21 FR FR7824288A patent/FR2403418A1/fr active Granted
- 1978-09-15 BR BR7806050A patent/BR7806050A/pt unknown
- 1978-09-19 BE BE6046608A patent/BE870607A/xx not_active IP Right Cessation
- 1978-09-19 CH CH978978A patent/CH638003A5/de not_active IP Right Cessation
- 1978-09-19 IT IT69162/78A patent/IT1109111B/it active
- 1978-09-19 AT AT0675678A patent/AT367812B/de not_active IP Right Cessation
- 1978-09-19 SE SE7809831A patent/SE7809831L/xx unknown
- 1978-09-19 GB GB7837320A patent/GB2005743B/en not_active Expired
- 1978-09-20 FI FI782869A patent/FI68273C/fi not_active IP Right Cessation
- 1978-09-20 ZA ZA00785356A patent/ZA785356B/xx unknown
- 1978-09-20 AR AR273785A patent/AR218936A1/es active
- 1978-09-20 CA CA311,653A patent/CA1133660A/en not_active Expired
- 1978-09-20 JP JP11470478A patent/JPS5455606A/ja active Pending

Also Published As

Publication number	Publication date
BR7806050A (pt)	1979-05-02
FR2403418B1 (it)	1982-07-02
CH638003A5 (de)	1983-08-31
GB2005743A (en)	1979-04-25
ZA785356B (en)	1979-09-26
FR2403418A1 (fr)	1979-04-13
SE7809831L (sv)	1979-03-21
GB2005743B (en)	1982-03-03
NO782820L (no)	1979-03-21
FI68273B (fi)	1985-04-30
IT1109111B (it)	1985-12-16
DE2742262A1 (de)	1979-03-29
ES472687A1 (es)	1979-02-16
BE870607A (fr)	1979-03-19
AR218936A1 (es)	1980-07-15
IT7869162A0 (it)	1978-09-19
NO153978B (no)	1986-03-17
DE2742262C2 (de)	1982-06-09
FI782869A7 (fi)	1979-03-21
JPS5455606A (en)	1979-05-02
FI68273C (fi)	1985-08-12
ATA675678A (de)	1981-12-15
AT367812B (de)	1982-08-10
NO153978C (no)	1986-06-25

Legal Events

Date	Code	Title	Description
1999-10-19	MKEX	Expiry

Publication	Publication Date	Title
US2587064A (en)	1952-02-26	Method of bleaching wood pulp
US4661205A (en)	1987-04-28	Method of bleaching lignocellulosic material with peroxide catalyzed with a salt of a metal
US3663357A (en)	1972-05-16	Bleaching of mechanical cellulosic pulp with ozone in the presence of a peroxygen compound
US1860431A (en)	1932-05-31	Process of producing low-viscosity cellulose fiber
US2975169A (en)	1961-03-14	Bleaching of cellulose pulp
US3691008A (en)	1972-09-12	Two-stage soda-oxygen pulping
US2129719A (en)	1938-09-13	Bleaching method
US3382149A (en)	1968-05-07	Bleaching of hardwood sulfite pulp with hydrogen peroxide, including pretreatment with alkali
DE2742262C2 (de)	1982-06-09	Verfahren zur Herstellung eines mittel- bis hochviskosen Nadelholz-Sulfitzellstoffs
US3532597A (en)	1970-10-06	Preparation of dissolving pulps from wood by hydrolysis and alkaline sulfite digestion
US3017316A (en)	1962-01-16	Method of bleaching wood pulp with chlorine dioxide and sodium borohydride
RU2019613C1 (ru)	1994-09-15	Способ отбелки лиственной сульфатной целлюлозы
US1880043A (en)	1932-09-27	Production of high grade chemical pulps
US1838326A (en)	1931-12-29	Refined wood pulp of low pentosan content
US2527563A (en)	1950-10-31	Method of bleaching semichemical pulps
US2249174A (en)	1941-07-15	Process for producing white wood pulp of high solution viscosity and purity
US2694631A (en)	1954-11-16	Process of preparing wood pulp
US2140863A (en)	1938-12-20	Process for producing a pure white cellulose
US2380706A (en)	1945-07-31	Production of refined wood pulp
US4295928A (en)	1981-10-20	Phenolic compounds as viscosity preservatives during hypochlorite pulp bleaching
US1822125A (en)	1931-09-08	Method for the treatment of cellulosic materials
US3650887A (en)	1972-03-21	Wood pulp bleaching process utilizing peroxide-silicate bleaching solution
US3817825A (en)	1974-06-18	Bleaching and refining process for producing dissolving pulps
US3594270A (en)	1971-07-20	Upgrading unbleached sulfite pulps
US1811864A (en)	1931-06-30	Process of liberating fiber from bagasse or like stalks