CA2170733A1 - Medium consistency ozone brightening of high consistency ozone bleached pulp - Google Patents

Medium consistency ozone brightening of high consistency ozone bleached pulp

Info

Publication number: CA2170733A1
Authority: CA; Canada
Prior art keywords: pulp; ozone; brightness; peroxide; consistency
Prior art date: 1993-09-03
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.): Abandoned

Application number

CA002170733A

Other languages

English (en)

French (fr)

Inventor

Spencer W. Eachus

Omar F. Ali

George Pangalos

Bruce F. Griggs

Thomas P. Gandek

Michael A. Pikulin

Allen Rosen

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.)

Union Camp Patent Holding Inc

Original Assignee

Individual

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.)

1993-09-03

Filing date

1994-09-01

Publication date

1995-03-09

1994-09-01 Application filed by Individual filed Critical Individual

1995-03-09 Publication of CA2170733A1 publication Critical patent/CA2170733A1/en

Status Abandoned legal-status Critical Current

Links

CBENFWSGALASAD-UHFFFAOYSA-N Ozone Chemical compound [O-][O+]=O CBENFWSGALASAD-UHFFFAOYSA-N 0.000 title claims abstract description 197
238000005282 brightening Methods 0.000 title claims abstract description 57
238000000034 method Methods 0.000 claims abstract description 106
230000008569 process Effects 0.000 claims abstract description 86
229910052760 oxygen Inorganic materials 0.000 claims abstract description 66
QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 claims abstract description 64
239000001301 oxygen Substances 0.000 claims abstract description 64
-1 peroxide compound Chemical class 0.000 claims abstract description 31
239000012978 lignocellulosic material Substances 0.000 claims abstract description 8
150000002978 peroxides Chemical class 0.000 claims description 99
230000001965 increasing effect Effects 0.000 claims description 94
238000011282 treatment Methods 0.000 claims description 84
239000000463 material Substances 0.000 claims description 59
239000002245 particle Substances 0.000 claims description 42
238000006243 chemical reaction Methods 0.000 claims description 38
229920005610 lignin Polymers 0.000 claims description 33
238000000605 extraction Methods 0.000 claims description 24
238000002156 mixing Methods 0.000 claims description 19
239000003381 stabilizer Substances 0.000 claims description 18
239000000654 additive Substances 0.000 claims description 14
239000008246 gaseous mixture Substances 0.000 claims description 14
230000002829 reductive effect Effects 0.000 claims description 9
239000012279 sodium borohydride Substances 0.000 claims description 9
229910000033 sodium borohydride Inorganic materials 0.000 claims description 9
230000000996 additive effect Effects 0.000 claims description 8
JVBXVOWTABLYPX-UHFFFAOYSA-L sodium dithionite Chemical compound [Na+].[Na+].[O-]S(=O)S([O-])=O JVBXVOWTABLYPX-UHFFFAOYSA-L 0.000 claims description 7
NYYSPVRERVXMLJ-UHFFFAOYSA-N 4,4-difluorocyclohexan-1-one Chemical compound FC1(F)CCC(=O)CC1 NYYSPVRERVXMLJ-UHFFFAOYSA-N 0.000 claims description 6
238000004519 manufacturing process Methods 0.000 claims description 3
238000004061 bleaching Methods 0.000 abstract description 54
ZAMOUSCENKQFHK-UHFFFAOYSA-N Chlorine atom Chemical compound [Cl] ZAMOUSCENKQFHK-UHFFFAOYSA-N 0.000 abstract description 9
239000000460 chlorine Substances 0.000 abstract description 9
229910052801 chlorine Inorganic materials 0.000 abstract description 9
150000001875 compounds Chemical class 0.000 abstract description 5
239000012467 final product Substances 0.000 abstract description 5
HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 description 36
XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 36
239000007789 gas Substances 0.000 description 32
239000000126 substance Substances 0.000 description 29
MHAJPDPJQMAIIY-UHFFFAOYSA-N Hydrogen peroxide Chemical compound OO MHAJPDPJQMAIIY-UHFFFAOYSA-N 0.000 description 28
239000011122 softwood Substances 0.000 description 28
CSNNHWWHGAXBCP-UHFFFAOYSA-L Magnesium sulfate Chemical compound [Mg+2].[O-][S+2]([O-])([O-])[O-] CSNNHWWHGAXBCP-UHFFFAOYSA-L 0.000 description 24
238000005406 washing Methods 0.000 description 24
239000002655 kraft paper Substances 0.000 description 21
238000004537 pulping Methods 0.000 description 20
239000007844 bleaching agent Substances 0.000 description 17
239000011121 hardwood Substances 0.000 description 17
239000000203 mixture Substances 0.000 description 16
239000000835 fiber Substances 0.000 description 13
239000007788 liquid Substances 0.000 description 12
229910052943 magnesium sulfate Inorganic materials 0.000 description 12
235000019341 magnesium sulphate Nutrition 0.000 description 12
KFSLWBXXFJQRDL-UHFFFAOYSA-N Peracetic acid Chemical compound CC(=O)OO KFSLWBXXFJQRDL-UHFFFAOYSA-N 0.000 description 11
230000007423 decrease Effects 0.000 description 11
QPCDCPDFJACHGM-UHFFFAOYSA-N N,N-bis{2-[bis(carboxymethyl)amino]ethyl}glycine Chemical compound OC(=O)CN(CC(O)=O)CCN(CC(=O)O)CCN(CC(O)=O)CC(O)=O QPCDCPDFJACHGM-UHFFFAOYSA-N 0.000 description 10
239000000243 solution Substances 0.000 description 10
229920002678 cellulose Polymers 0.000 description 9
239000001913 cellulose Substances 0.000 description 9
230000009467 reduction Effects 0.000 description 9
235000005018 Pinus echinata Nutrition 0.000 description 8
241001236219 Pinus echinata Species 0.000 description 8
235000017339 Pinus palustris Nutrition 0.000 description 8
230000008901 benefit Effects 0.000 description 8
239000002023 wood Substances 0.000 description 8
KCXVZYZYPLLWCC-UHFFFAOYSA-N EDTA Chemical compound OC(=O)CN(CC(O)=O)CCN(CC(O)=O)CC(O)=O KCXVZYZYPLLWCC-UHFFFAOYSA-N 0.000 description 7
241000196324 Embryophyta Species 0.000 description 7
235000008331 Pinus X rigitaeda Nutrition 0.000 description 7
235000011613 Pinus brutia Nutrition 0.000 description 7
241000018646 Pinus brutia Species 0.000 description 7
238000011084 recovery Methods 0.000 description 7
MUBZPKHOEPUJKR-UHFFFAOYSA-N Oxalic acid Chemical compound OC(=O)C(O)=O MUBZPKHOEPUJKR-UHFFFAOYSA-N 0.000 description 6
239000013522 chelant Substances 0.000 description 6
239000002738 chelating agent Substances 0.000 description 6
239000003795 chemical substances by application Substances 0.000 description 6
238000010411 cooking Methods 0.000 description 6
238000002474 experimental method Methods 0.000 description 6
229910021645 metal ion Inorganic materials 0.000 description 6
238000006385 ozonation reaction Methods 0.000 description 6
239000000123 paper Substances 0.000 description 6
239000004115 Sodium Silicate Substances 0.000 description 5
230000015556 catabolic process Effects 0.000 description 5
230000000694 effects Effects 0.000 description 5
230000007935 neutral effect Effects 0.000 description 5
239000000047 product Substances 0.000 description 5
230000004044 response Effects 0.000 description 5
NTHWMYGWWRZVTN-UHFFFAOYSA-N sodium silicate Chemical compound [Na+].[Na+].[O-][Si]([O-])=O NTHWMYGWWRZVTN-UHFFFAOYSA-N 0.000 description 5
229910052911 sodium silicate Inorganic materials 0.000 description 5
239000002253 acid Substances 0.000 description 4
238000000354 decomposition reaction Methods 0.000 description 4
238000006731 degradation reaction Methods 0.000 description 4
OSVXSBDYLRYLIG-UHFFFAOYSA-N dioxidochlorine(.) Chemical compound O=Cl=O OSVXSBDYLRYLIG-UHFFFAOYSA-N 0.000 description 4
239000013505 freshwater Substances 0.000 description 4
230000008719 thickening Effects 0.000 description 4
229920001131 Pulp (paper) Polymers 0.000 description 3
238000010306 acid treatment Methods 0.000 description 3
230000002378 acidificating effect Effects 0.000 description 3
230000002411 adverse Effects 0.000 description 3
239000003513 alkali Substances 0.000 description 3
239000012670 alkaline solution Substances 0.000 description 3
PYKYMHQGRFAEBM-UHFFFAOYSA-N anthraquinone Natural products CCC(=O)c1c(O)c2C(=O)C3C(C=CC=C3O)C(=O)c2cc1CC(=O)OC PYKYMHQGRFAEBM-UHFFFAOYSA-N 0.000 description 3
150000004056 anthraquinones Chemical class 0.000 description 3
239000012159 carrier gas Substances 0.000 description 3
239000006185 dispersion Substances 0.000 description 3
229910052751 metal Inorganic materials 0.000 description 3
239000002184 metal Substances 0.000 description 3
150000004965 peroxy acids Chemical class 0.000 description 3
238000012545 processing Methods 0.000 description 3
QTBSBXVTEAMEQO-UHFFFAOYSA-N Acetic acid Natural products CC(O)=O QTBSBXVTEAMEQO-UHFFFAOYSA-N 0.000 description 2
239000004155 Chlorine dioxide Substances 0.000 description 2
244000166124 Eucalyptus globulus Species 0.000 description 2
FYYHWMGAXLPEAU-UHFFFAOYSA-N Magnesium Chemical compound [Mg] FYYHWMGAXLPEAU-UHFFFAOYSA-N 0.000 description 2
QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 description 2
230000003190 augmentative effect Effects 0.000 description 2
230000015572 biosynthetic process Effects 0.000 description 2
125000002915 carbonyl group Chemical group [*:2]C([*:1])=O 0.000 description 2
230000008859 change Effects 0.000 description 2
150000001805 chlorine compounds Chemical class 0.000 description 2
235000019398 chlorine dioxide Nutrition 0.000 description 2
230000001143 conditioned effect Effects 0.000 description 2
230000003750 conditioning effect Effects 0.000 description 2
230000003247 decreasing effect Effects 0.000 description 2
230000001419 dependent effect Effects 0.000 description 2
238000013461 design Methods 0.000 description 2
230000007613 environmental effect Effects 0.000 description 2
239000000706 filtrate Substances 0.000 description 2
238000009897 hydrogen peroxide bleaching Methods 0.000 description 2
230000006872 improvement Effects 0.000 description 2
239000011777 magnesium Substances 0.000 description 2
229910052749 magnesium Inorganic materials 0.000 description 2
150000002739 metals Chemical class 0.000 description 2
BDAGIHXWWSANSR-UHFFFAOYSA-N methanoic acid Natural products OC=O BDAGIHXWWSANSR-UHFFFAOYSA-N 0.000 description 2
230000004048 modification Effects 0.000 description 2
238000012986 modification Methods 0.000 description 2
235000006408 oxalic acid Nutrition 0.000 description 2
230000035515 penetration Effects 0.000 description 2
150000004968 peroxymonosulfuric acids Chemical class 0.000 description 2
238000004076 pulp bleaching Methods 0.000 description 2
238000010791 quenching Methods 0.000 description 2
238000012216 screening Methods 0.000 description 2
229910052979 sodium sulfide Inorganic materials 0.000 description 2
GRVFOGOEDUUMBP-UHFFFAOYSA-N sodium sulfide (anhydrous) Chemical compound [Na+].[Na+].[S-2] GRVFOGOEDUUMBP-UHFFFAOYSA-N 0.000 description 2
241000894007 species Species 0.000 description 2
239000007921 spray Substances 0.000 description 2
238000012360 testing method Methods 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
229910004878 Na2S2O4 Inorganic materials 0.000 description 1
LYXFCGCYJQCSRL-UHFFFAOYSA-N OOSO Chemical compound OOSO LYXFCGCYJQCSRL-UHFFFAOYSA-N 0.000 description 1
101100311043 Salmonella typhimurium (strain LT2 / SGSC1412 / ATCC 700720) sseC gene Proteins 0.000 description 1
150000007513 acids Chemical class 0.000 description 1
230000004913 activation Effects 0.000 description 1
230000003466 anti-cipated effect Effects 0.000 description 1
239000007864 aqueous solution Substances 0.000 description 1
125000000837 carbohydrate group Chemical group 0.000 description 1
230000005465 channeling Effects 0.000 description 1
230000009920 chelation Effects 0.000 description 1
239000007795 chemical reaction product Substances 0.000 description 1
239000003638 chemical reducing agent Substances 0.000 description 1
230000003749 cleanliness Effects 0.000 description 1
238000005056 compaction Methods 0.000 description 1
230000007797 corrosion Effects 0.000 description 1
238000005260 corrosion Methods 0.000 description 1
230000007812 deficiency Effects 0.000 description 1
230000001627 detrimental effect Effects 0.000 description 1
238000010790 dilution Methods 0.000 description 1
239000012895 dilution Substances 0.000 description 1
230000008030 elimination Effects 0.000 description 1
238000003379 elimination reaction Methods 0.000 description 1
235000019253 formic acid Nutrition 0.000 description 1
230000001939 inductive effect Effects 0.000 description 1
239000011261 inert gas Substances 0.000 description 1
150000002500 ions Chemical class 0.000 description 1
230000000670 limiting effect Effects 0.000 description 1
150000007522 mineralic acids Chemical class 0.000 description 1
150000007524 organic acids Chemical class 0.000 description 1
239000007800 oxidant agent Substances 0.000 description 1
230000001590 oxidative effect Effects 0.000 description 1
150000002926 oxygen Chemical class 0.000 description 1
230000000704 physical effect Effects 0.000 description 1
230000000171 quenching effect Effects 0.000 description 1
239000000376 reactant Substances 0.000 description 1
238000009895 reductive bleaching Methods 0.000 description 1
238000009877 rendering Methods 0.000 description 1
238000005096 rolling process Methods 0.000 description 1
150000003839 salts Chemical class 0.000 description 1
238000002791 soaking Methods 0.000 description 1
239000007787 solid Substances 0.000 description 1
238000005063 solubilization Methods 0.000 description 1
230000007928 solubilization Effects 0.000 description 1
238000005507 spraying Methods 0.000 description 1
230000003068 static effect Effects 0.000 description 1
125000001424 substituent group Chemical group 0.000 description 1
238000009827 uniform distribution Methods 0.000 description 1
230000003313 weakening effect Effects 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
- D21C9/10—Bleaching ; Apparatus therefor
- D21C9/147—Bleaching ; Apparatus therefor with oxygen or its allotropic modifications
- D21C9/153—Bleaching ; Apparatus therefor with oxygen or its allotropic modifications with ozone
- 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
- D21C9/10—Bleaching ; Apparatus therefor
- D21C9/1057—Multistage, with compounds cited in more than one sub-group D21C9/10, D21C9/12, D21C9/16
- 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
- D21C9/10—Bleaching ; Apparatus therefor
- D21C9/147—Bleaching ; Apparatus therefor with oxygen or its allotropic modifications
- 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
- D21C9/10—Bleaching ; Apparatus therefor
- D21C9/16—Bleaching ; Apparatus therefor with per compounds
- D21C9/163—Bleaching ; Apparatus therefor with per compounds with peroxides

Landscapes

Life Sciences & Earth Sciences (AREA)
Engineering & Computer Science (AREA)
Wood Science & Technology (AREA)
Paper (AREA)

CA002170733A 1993-09-03 1994-09-01 Medium consistency ozone brightening of high consistency ozone bleached pulp Abandoned CA2170733A1 (en)

Applications Claiming Priority (2)

Application Number	Priority Date	Filing Date	Title
US11677693A	1993-09-03	1993-09-03
US116,776		1993-09-03

Publications (1)

Publication Number	Publication Date
CA2170733A1 true CA2170733A1 (en)	1995-03-09

Family

ID=22369146

Family Applications (1)

Application Number	Title	Priority Date	Filing Date
CA002170733A Abandoned CA2170733A1 (en)	1993-09-03	1994-09-01	Medium consistency ozone brightening of high consistency ozone bleached pulp

Country Status (8)

Country	Link
EP (1)	EP0717800A4 (sv)
AU (1)	AU7721694A (sv)
BR (1)	BR9407457A (sv)
CA (1)	CA2170733A1 (sv)
FI (1)	FI960973A (sv)
SE (1)	SE9600773L (sv)
WO (1)	WO1995006773A1 (sv)
ZA (1)	ZA946807B (sv)

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number	Priority date	Publication date	Assignee	Title
GB2382592A (en) *	2001-11-30	2003-06-04	Sca Hygiene Prod Gmbh	Use of ozone to enhance the wet strength of fibrous cellulosic material
GB2391011A (en) *	2002-07-19	2004-01-28	Crosmill Ltd	Bleaching cellulose suspensions
US9932709B2 (en)	2013-03-15	2018-04-03	Ecolab Usa Inc.	Processes and compositions for brightness improvement in paper production
FR3007044B1 (fr) *	2013-06-13	2016-01-15	Air Liquide	Procede de traitement des pates papetieres chimiques par traitement a l'ozone en presence d'ions magnesium

Family Cites Families (6)

* Cited by examiner, † Cited by third party
Publication number	Priority date	Publication date	Assignee	Title
US5173153A (en) *	1991-01-03	1992-12-22	Union Camp Patent Holding, Inc.	Process for enhanced oxygen delignification using high consistency and a split alkali addition
EP0402335B2 (en) *	1989-06-06	2001-03-14	Eka Chemicals AB	Process for bleaching lignocellulose-containing pulps
AU636173B2 (en) *	1989-10-30	1993-04-22	Lenzing Aktiengesellschaft	Method for the chlorine-free bleaching of pulps
BR9007533A (pt) *	1990-05-17	1992-04-28	Union Camp Corp	Processo para fabricacao de polpa alvejada e para deslignificar e alvejar um material lignoscelulosico
US5328564A (en) *	1990-09-17	1994-07-12	Kamyr, Inc.	Modified digestion of paper pulp followed by ozone bleaching
CA2089516A1 (en) *	1992-02-21	1993-08-22	Kaj Henricson	Chlorine free pulping and bleaching sequence

1994
- 1994-09-01 EP EP94928024A patent/EP0717800A4/en not_active Withdrawn
- 1994-09-01 BR BR9407457A patent/BR9407457A/pt not_active Application Discontinuation
- 1994-09-01 AU AU77216/94A patent/AU7721694A/en not_active Abandoned
- 1994-09-01 CA CA002170733A patent/CA2170733A1/en not_active Abandoned
- 1994-09-01 WO PCT/US1994/010050 patent/WO1995006773A1/en not_active Application Discontinuation
- 1994-09-05 ZA ZA946807A patent/ZA946807B/xx unknown
1996
- 1996-02-28 SE SE9600773A patent/SE9600773L/sv not_active Application Discontinuation
- 1996-03-01 FI FI960973A patent/FI960973A/sv unknown

Also Published As

Publication number	Publication date
AU7721694A (en)	1995-03-22
FI960973A (sv)	1996-04-30
SE9600773L (sv)	1996-04-18
ZA946807B (en)	1995-06-28
EP0717800A4 (en)	1998-10-28
FI960973A0 (sv)	1996-03-01
EP0717800A1 (en)	1996-06-26
WO1995006773A1 (en)	1995-03-09
BR9407457A (pt)	1996-11-12
SE9600773D0 (sv)	1996-02-28

Legal Events

Date	Code	Title	Description
2000-09-01	FZDE	Discontinued
2023-05-26	FZDE	Discontinued	Effective date: 20000901

Publication	Publication Date	Title
US5164044A (en)	1992-11-17	Environmentally improved process for bleaching lignocellulosic materials with ozone
CA1259456A (en)	1989-09-19	Enhanced oxidative extraction
JP2825346B2 (ja)	1998-11-18	リグノセルロース物質の環境上改良された漂白方法
US5164043A (en)	1992-11-17	Environmentally improved process for bleaching lignocellulosic materials with ozone
CA1150011A (en)	1983-07-19	Method at bleaching ligno-cellulose containing material
US5211811A (en)	1993-05-18	Process for high consistency oxygen delignification of alkaline treated pulp followed by ozone delignification
US5409570A (en)	1995-04-25	Process for ozone bleaching of oxygen delignified pulp while conveying the pulp through a reaction zone
US5656130A (en)	1997-08-12	Ambient temperature pulp bleaching with peroxyacid salts
CA2111519C (en)	2001-07-31	Oxygen/ozone/peracetic acid delignification and bleaching of cellulosic pulps
US5188708A (en)	1993-02-23	Process for high consistency oxygen delignification followed by ozone relignification
FI105213B (sv)	2000-06-30	Förfarande för framställning av blekt massa från lignocellulosamaterial
US5728264A (en)	1998-03-17	Avoidance of salt scaling by acidic pulp washing process
CA2099881A1 (en)	1992-07-04	Chlorine-free process for bleaching lignocellulosic pulp
CA2170733A1 (en)	1995-03-09	Medium consistency ozone brightening of high consistency ozone bleached pulp
CA1147909A (en)	1983-06-14	Method for delignifying and/or bleaching cellulose pulp
USH1690H (en)	1997-11-04	Process for bleaching kraft pulp
US5441603A (en)	1995-08-15	Method for chelation of pulp prior to ozone delignification
US5525195A (en)	1996-06-11	Process for high consistency delignification using a low consistency alkali pretreatment
EP0530881A1 (en)	1993-03-10	Use of wash press for pulp alkali addition process
EP0720676A1 (en)	1996-07-10	Improved method for bleaching lignocellulosic pulp
AU647973B2 (en)	1994-03-31	Wash press modification for oxygen delignification process
CA2311718A1 (en)	2000-12-14	Oxygen delignification of lignocellulosic material
JP3697335B2 (ja)	2005-09-21	化学パルプの酸性漂白白水による処理方法
EP0863251A1 (en)	1998-09-09	Process for producing bleached pulp