CA2170733A1 - Medium consistency ozone brightening of high consistency ozone bleached pulp - Google Patents
Medium consistency ozone brightening of high consistency ozone bleached pulpInfo
- Publication number
- CA2170733A1 CA2170733A1 CA002170733A CA2170733A CA2170733A1 CA 2170733 A1 CA2170733 A1 CA 2170733A1 CA 002170733 A CA002170733 A CA 002170733A CA 2170733 A CA2170733 A CA 2170733A CA 2170733 A1 CA2170733 A1 CA 2170733A1
- Authority
- CA
- Canada
- Prior art keywords
- pulp
- ozone
- brightness
- peroxide
- consistency
- Prior art date
- 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
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)
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)
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)
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 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US5164044A (en) | Environmentally improved process for bleaching lignocellulosic materials with ozone | |
CA1259456A (en) | Enhanced oxidative extraction | |
JP2825346B2 (ja) | 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) | Environmentally improved process for bleaching lignocellulosic materials with ozone | |
CA1150011A (en) | Method at bleaching ligno-cellulose containing material | |
US5211811A (en) | Process for high consistency oxygen delignification of alkaline treated pulp followed by ozone delignification | |
US5409570A (en) | Process for ozone bleaching of oxygen delignified pulp while conveying the pulp through a reaction zone | |
US5656130A (en) | Ambient temperature pulp bleaching with peroxyacid salts | |
CA2111519C (en) | Oxygen/ozone/peracetic acid delignification and bleaching of cellulosic pulps | |
US5188708A (en) | Process for high consistency oxygen delignification followed by ozone relignification | |
FI105213B (sv) | Förfarande för framställning av blekt massa från lignocellulosamaterial | |
US5728264A (en) | Avoidance of salt scaling by acidic pulp washing process | |
CA2099881A1 (en) | Chlorine-free process for bleaching lignocellulosic pulp | |
CA2170733A1 (en) | Medium consistency ozone brightening of high consistency ozone bleached pulp | |
CA1147909A (en) | Method for delignifying and/or bleaching cellulose pulp | |
USH1690H (en) | Process for bleaching kraft pulp | |
US5441603A (en) | Method for chelation of pulp prior to ozone delignification | |
US5525195A (en) | Process for high consistency delignification using a low consistency alkali pretreatment | |
EP0530881A1 (en) | Use of wash press for pulp alkali addition process | |
EP0720676A1 (en) | Improved method for bleaching lignocellulosic pulp | |
AU647973B2 (en) | Wash press modification for oxygen delignification process | |
CA2311718A1 (en) | Oxygen delignification of lignocellulosic material | |
JP3697335B2 (ja) | 化学パルプの酸性漂白白水による処理方法 | |
EP0863251A1 (en) | Process for producing bleached pulp |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
FZDE | Discontinued | ||
FZDE | Discontinued |
Effective date: 20000901 |