CA1154205A - Brightness improvement of ozone bleached pulps - Google Patents
Brightness improvement of ozone bleached pulpsInfo
- Publication number
- CA1154205A CA1154205A CA000372737A CA372737A CA1154205A CA 1154205 A CA1154205 A CA 1154205A CA 000372737 A CA000372737 A CA 000372737A CA 372737 A CA372737 A CA 372737A CA 1154205 A CA1154205 A CA 1154205A
- Authority
- CA
- Canada
- Prior art keywords
- pulp
- ozone
- bleaching
- hydrosulfite
- oxygen
- 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.)
- Expired
Links
- CBENFWSGALASAD-UHFFFAOYSA-N Ozone Chemical compound [O-][O+]=O CBENFWSGALASAD-UHFFFAOYSA-N 0.000 title claims description 35
- 230000006872 improvement Effects 0.000 title claims description 4
- 238000000605 extraction Methods 0.000 claims abstract description 38
- GRWZHXKQBITJKP-UHFFFAOYSA-L dithionite(2-) Chemical compound [O-]S(=O)S([O-])=O GRWZHXKQBITJKP-UHFFFAOYSA-L 0.000 claims abstract description 31
- 239000002655 kraft paper Substances 0.000 claims abstract description 14
- 229920001131 Pulp (paper) Polymers 0.000 claims abstract description 3
- 238000004061 bleaching Methods 0.000 claims description 67
- 238000000034 method Methods 0.000 claims description 44
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 claims description 25
- 229910052760 oxygen Inorganic materials 0.000 claims description 25
- 239000001301 oxygen Substances 0.000 claims description 25
- 238000011282 treatment Methods 0.000 claims description 25
- 150000002978 peroxides Chemical class 0.000 claims description 19
- KFSLWBXXFJQRDL-UHFFFAOYSA-N Peracetic acid Chemical group CC(=O)OO KFSLWBXXFJQRDL-UHFFFAOYSA-N 0.000 claims description 14
- 230000002708 enhancing effect Effects 0.000 claims description 2
- OGIIWTRTOXDWEH-UHFFFAOYSA-N [O].[O-][O+]=O Chemical compound [O].[O-][O+]=O OGIIWTRTOXDWEH-UHFFFAOYSA-N 0.000 abstract description 3
- 239000000126 substance Substances 0.000 description 9
- 238000005406 washing Methods 0.000 description 9
- JVBXVOWTABLYPX-UHFFFAOYSA-L sodium dithionite Chemical compound [Na+].[Na+].[O-]S(=O)S([O-])=O JVBXVOWTABLYPX-UHFFFAOYSA-L 0.000 description 8
- 238000006385 ozonation reaction Methods 0.000 description 6
- 239000000123 paper Substances 0.000 description 6
- 239000000243 solution Substances 0.000 description 6
- 238000005282 brightening Methods 0.000 description 5
- OSVXSBDYLRYLIG-UHFFFAOYSA-N dioxidochlorine(.) Chemical compound O=Cl=O OSVXSBDYLRYLIG-UHFFFAOYSA-N 0.000 description 5
- -1 hydrosulfite ion Chemical class 0.000 description 5
- 150000004965 peroxy acids Chemical class 0.000 description 5
- RAHZWNYVWXNFOC-UHFFFAOYSA-N Sulphur dioxide Chemical compound O=S=O RAHZWNYVWXNFOC-UHFFFAOYSA-N 0.000 description 4
- 239000007844 bleaching agent Substances 0.000 description 4
- 239000004155 Chlorine dioxide Substances 0.000 description 3
- 235000005018 Pinus echinata Nutrition 0.000 description 3
- 241001236219 Pinus echinata Species 0.000 description 3
- 235000017339 Pinus palustris Nutrition 0.000 description 3
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 description 3
- 150000001768 cations Chemical class 0.000 description 3
- 235000019398 chlorine dioxide Nutrition 0.000 description 3
- 229910052751 metal Inorganic materials 0.000 description 3
- 239000002184 metal Substances 0.000 description 3
- 239000011122 softwood Substances 0.000 description 3
- ZAMOUSCENKQFHK-UHFFFAOYSA-N Chlorine atom Chemical compound [Cl] ZAMOUSCENKQFHK-UHFFFAOYSA-N 0.000 description 2
- FAPWRFPIFSIZLT-UHFFFAOYSA-M Sodium chloride Chemical compound [Na+].[Cl-] FAPWRFPIFSIZLT-UHFFFAOYSA-M 0.000 description 2
- 239000002253 acid Substances 0.000 description 2
- 230000032683 aging Effects 0.000 description 2
- 238000010009 beating Methods 0.000 description 2
- 238000006243 chemical reaction Methods 0.000 description 2
- 229940060038 chlorine Drugs 0.000 description 2
- 229940099041 chlorine dioxide Drugs 0.000 description 2
- GRWZHXKQBITJKP-UHFFFAOYSA-N dithionous acid Chemical class OS(=O)S(O)=O GRWZHXKQBITJKP-UHFFFAOYSA-N 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 230000007717 exclusion Effects 0.000 description 2
- 239000000706 filtrate Substances 0.000 description 2
- 239000011121 hardwood Substances 0.000 description 2
- 230000001965 increasing effect Effects 0.000 description 2
- 229920005610 lignin Polymers 0.000 description 2
- 230000000704 physical effect Effects 0.000 description 2
- 239000000047 product Substances 0.000 description 2
- 238000004076 pulp bleaching Methods 0.000 description 2
- 230000035484 reaction time Effects 0.000 description 2
- 150000003839 salts Chemical class 0.000 description 2
- 239000000758 substrate Substances 0.000 description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 2
- 241000609240 Ambelania acida Species 0.000 description 1
- 229920003043 Cellulose fiber Polymers 0.000 description 1
- VEXZGXHMUGYJMC-UHFFFAOYSA-M Chloride anion Chemical compound [Cl-] VEXZGXHMUGYJMC-UHFFFAOYSA-M 0.000 description 1
- VYZAMTAEIAYCRO-UHFFFAOYSA-N Chromium Chemical compound [Cr] VYZAMTAEIAYCRO-UHFFFAOYSA-N 0.000 description 1
- 101150105088 Dele1 gene Proteins 0.000 description 1
- DGAQECJNVWCQMB-PUAWFVPOSA-M Ilexoside XXIX Chemical compound C[C@@H]1CC[C@@]2(CC[C@@]3(C(=CC[C@H]4[C@]3(CC[C@@H]5[C@@]4(CC[C@@H](C5(C)C)OS(=O)(=O)[O-])C)C)[C@@H]2[C@]1(C)O)C)C(=O)O[C@H]6[C@@H]([C@H]([C@@H]([C@H](O6)CO)O)O)O.[Na+] DGAQECJNVWCQMB-PUAWFVPOSA-M 0.000 description 1
- ZOKXTWBITQBERF-UHFFFAOYSA-N Molybdenum Chemical compound [Mo] ZOKXTWBITQBERF-UHFFFAOYSA-N 0.000 description 1
- BUGBHKTXTAQXES-UHFFFAOYSA-N Selenium Chemical compound [Se] BUGBHKTXTAQXES-UHFFFAOYSA-N 0.000 description 1
- 241001062472 Stokellia anisodon Species 0.000 description 1
- QAOWNCQODCNURD-UHFFFAOYSA-L Sulfate Chemical compound [O-]S([O-])(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-L 0.000 description 1
- LSNNMFCWUKXFEE-UHFFFAOYSA-N Sulfurous acid Chemical compound OS(O)=O LSNNMFCWUKXFEE-UHFFFAOYSA-N 0.000 description 1
- ATJFFYVFTNAWJD-UHFFFAOYSA-N Tin Chemical compound [Sn] ATJFFYVFTNAWJD-UHFFFAOYSA-N 0.000 description 1
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 description 1
- HCHKCACWOHOZIP-UHFFFAOYSA-N Zinc Chemical compound [Zn] HCHKCACWOHOZIP-UHFFFAOYSA-N 0.000 description 1
- 238000010521 absorption reaction Methods 0.000 description 1
- 230000002378 acidificating effect Effects 0.000 description 1
- 239000012190 activator Substances 0.000 description 1
- 238000007792 addition Methods 0.000 description 1
- 230000002730 additional effect Effects 0.000 description 1
- 239000003513 alkali Substances 0.000 description 1
- 229910052784 alkaline earth metal Inorganic materials 0.000 description 1
- 239000010905 bagasse Substances 0.000 description 1
- 230000009172 bursting Effects 0.000 description 1
- 125000003178 carboxy group Chemical group [H]OC(*)=O 0.000 description 1
- 125000002091 cationic group Chemical group 0.000 description 1
- 239000003518 caustics Substances 0.000 description 1
- 229920002678 cellulose Polymers 0.000 description 1
- 239000001913 cellulose Substances 0.000 description 1
- 239000003153 chemical reaction reagent Substances 0.000 description 1
- 239000000460 chlorine Substances 0.000 description 1
- 235000017168 chlorine Nutrition 0.000 description 1
- 229910001902 chlorine oxide Inorganic materials 0.000 description 1
- 229910052804 chromium Inorganic materials 0.000 description 1
- 239000011651 chromium Substances 0.000 description 1
- 230000001427 coherent effect Effects 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 239000000356 contaminant Substances 0.000 description 1
- 238000005260 corrosion Methods 0.000 description 1
- 230000007797 corrosion Effects 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 230000018109 developmental process Effects 0.000 description 1
- 238000004880 explosion Methods 0.000 description 1
- 239000013505 freshwater Substances 0.000 description 1
- 238000010348 incorporation Methods 0.000 description 1
- 150000002500 ions Chemical class 0.000 description 1
- 239000012978 lignocellulosic material Substances 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 229910052750 molybdenum Inorganic materials 0.000 description 1
- 239000011733 molybdenum Substances 0.000 description 1
- 229910052762 osmium Inorganic materials 0.000 description 1
- SYQBFIAQOQZEGI-UHFFFAOYSA-N osmium atom Chemical compound [Os] SYQBFIAQOQZEGI-UHFFFAOYSA-N 0.000 description 1
- 239000007800 oxidant agent Substances 0.000 description 1
- 238000009896 oxidative bleaching Methods 0.000 description 1
- 230000001590 oxidative effect Effects 0.000 description 1
- 238000002360 preparation method Methods 0.000 description 1
- 239000013055 pulp slurry Substances 0.000 description 1
- 238000004064 recycling Methods 0.000 description 1
- 238000009895 reductive bleaching Methods 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 229910052711 selenium Inorganic materials 0.000 description 1
- 239000011669 selenium Substances 0.000 description 1
- 238000000926 separation method Methods 0.000 description 1
- 239000011734 sodium Substances 0.000 description 1
- 229910052708 sodium Inorganic materials 0.000 description 1
- 239000011780 sodium chloride Substances 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 239000003381 stabilizer Substances 0.000 description 1
- 230000000087 stabilizing effect Effects 0.000 description 1
- 229910021653 sulphate ion Inorganic materials 0.000 description 1
- 229910052718 tin Inorganic materials 0.000 description 1
- 239000011135 tin Substances 0.000 description 1
- 229910052719 titanium Inorganic materials 0.000 description 1
- 239000010936 titanium Substances 0.000 description 1
- WFKWXMTUELFFGS-UHFFFAOYSA-N tungsten Chemical compound [W] WFKWXMTUELFFGS-UHFFFAOYSA-N 0.000 description 1
- 229910052721 tungsten Inorganic materials 0.000 description 1
- 239000010937 tungsten Substances 0.000 description 1
- 229910052720 vanadium Inorganic materials 0.000 description 1
- GPPXJZIENCGNKB-UHFFFAOYSA-N vanadium Chemical compound [V]#[V] GPPXJZIENCGNKB-UHFFFAOYSA-N 0.000 description 1
- 239000002351 wastewater Substances 0.000 description 1
- 230000003313 weakening effect Effects 0.000 description 1
- 239000011701 zinc Substances 0.000 description 1
- 229910052725 zinc Inorganic materials 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
- D21C9/1026—Other features in bleaching processes
- D21C9/1036—Use of compounds accelerating or improving the efficiency of the processes
Landscapes
- Life Sciences & Earth Sciences (AREA)
- Engineering & Computer Science (AREA)
- Wood Science & Technology (AREA)
- Paper (AREA)
- Inks, Pencil-Leads, Or Crayons (AREA)
- Dental Preparations (AREA)
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US14052080A | 1980-04-15 | 1980-04-15 | |
US140,520 | 1980-04-15 |
Publications (1)
Publication Number | Publication Date |
---|---|
CA1154205A true CA1154205A (en) | 1983-09-27 |
Family
ID=22491621
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
CA000372737A Expired CA1154205A (en) | 1980-04-15 | 1981-03-11 | Brightness improvement of ozone bleached pulps |
Country Status (4)
Country | Link |
---|---|
AU (1) | AU6957881A (no) |
CA (1) | CA1154205A (no) |
NO (1) | NO811305L (no) |
SE (1) | SE8101772L (no) |
Cited By (20)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5085734A (en) * | 1989-02-15 | 1992-02-04 | Union Camp Patent Holding, Inc. | Methods of high consistency oxygen delignification using a low consistency alkali pretreatment |
US5164043A (en) * | 1990-05-17 | 1992-11-17 | Union Camp Patent Holding, Inc. | Environmentally improved process for bleaching lignocellulosic materials with ozone |
US5164044A (en) * | 1990-05-17 | 1992-11-17 | Union Camp Patent Holding, Inc. | Environmentally improved process for bleaching lignocellulosic materials with ozone |
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 |
US5174861A (en) * | 1990-10-26 | 1992-12-29 | Union Camp Patent Holdings, Inc. | Method of bleaching high consistency pulp with ozone |
US5181989A (en) * | 1990-10-26 | 1993-01-26 | Union Camp Patent Holdings, Inc. | Reactor for bleaching high consistency pulp with ozone |
US5188708A (en) * | 1989-02-15 | 1993-02-23 | Union Camp Patent Holding, Inc. | Process for high consistency oxygen delignification followed by ozone relignification |
US5211811A (en) * | 1989-02-15 | 1993-05-18 | Union Camp Patent Holding, Inc. | Process for high consistency oxygen delignification of alkaline treated pulp followed by ozone delignification |
US5217574A (en) * | 1989-02-15 | 1993-06-08 | Union Camp Patent Holdings Inc. | Process for oxygen delignifying high consistency pulp by removing and recycling pressate from alkaline pulp |
US5409570A (en) * | 1989-02-15 | 1995-04-25 | Union Camp Patent Holding, Inc. | Process for ozone bleaching of oxygen delignified pulp while conveying the pulp through a reaction zone |
US5441603A (en) * | 1990-05-17 | 1995-08-15 | Union Camp Patent Holding, Inc. | Method for chelation of pulp prior to ozone delignification |
US5451296A (en) * | 1991-05-24 | 1995-09-19 | Union Camp Patent Holding, Inc. | Two stage pulp bleaching reactor |
US5472572A (en) * | 1990-10-26 | 1995-12-05 | Union Camp Patent Holding, Inc. | Reactor for bleaching high consistency pulp with ozone |
US5520783A (en) * | 1990-10-26 | 1996-05-28 | Union Camp Patent Holding, Inc. | Apparatus for bleaching high consistency pulp with ozone |
US5525195A (en) * | 1989-02-15 | 1996-06-11 | Union Camp Patent Holding, Inc. | Process for high consistency delignification using a low consistency alkali pretreatment |
US5554259A (en) * | 1993-10-01 | 1996-09-10 | Union Camp Patent Holdings, Inc. | Reduction of salt scale precipitation by control of process stream Ph and salt concentration |
US5672247A (en) * | 1995-03-03 | 1997-09-30 | Union Camp Patent Holding, Inc. | Control scheme for rapid pulp delignification and bleaching |
USH1690H (en) * | 1995-07-20 | 1997-11-04 | Nye; Jeffrey | Process for bleaching kraft pulp |
US5736004A (en) * | 1995-03-03 | 1998-04-07 | Union Camp Patent Holding, Inc. | Control scheme for rapid pulp delignification and bleaching |
US6007678A (en) * | 1992-11-27 | 1999-12-28 | Eka Nobel Ab | Process for delignification of lignocellulose-containing pulp with an organic peracid or salts thereof |
-
1981
- 1981-03-11 CA CA000372737A patent/CA1154205A/en not_active Expired
- 1981-03-20 SE SE8101772A patent/SE8101772L/xx not_active Application Discontinuation
- 1981-04-14 NO NO811305A patent/NO811305L/no unknown
- 1981-04-15 AU AU69578/81A patent/AU6957881A/en not_active Abandoned
Cited By (23)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5525195A (en) * | 1989-02-15 | 1996-06-11 | Union Camp Patent Holding, Inc. | Process for high consistency delignification using a low consistency alkali pretreatment |
US5409570A (en) * | 1989-02-15 | 1995-04-25 | Union Camp Patent Holding, Inc. | Process for ozone bleaching of oxygen delignified pulp while conveying the pulp through a reaction zone |
US5085734A (en) * | 1989-02-15 | 1992-02-04 | Union Camp Patent Holding, Inc. | Methods of high consistency oxygen delignification using a low consistency alkali pretreatment |
US5188708A (en) * | 1989-02-15 | 1993-02-23 | Union Camp Patent Holding, Inc. | Process for high consistency oxygen delignification followed by ozone relignification |
US5211811A (en) * | 1989-02-15 | 1993-05-18 | Union Camp Patent Holding, Inc. | Process for high consistency oxygen delignification of alkaline treated pulp followed by ozone delignification |
US5217574A (en) * | 1989-02-15 | 1993-06-08 | Union Camp Patent Holdings Inc. | Process for oxygen delignifying high consistency pulp by removing and recycling pressate from alkaline pulp |
US5164044A (en) * | 1990-05-17 | 1992-11-17 | Union Camp Patent Holding, Inc. | Environmentally improved process for bleaching lignocellulosic materials with ozone |
US5441603A (en) * | 1990-05-17 | 1995-08-15 | Union Camp Patent Holding, Inc. | Method for chelation of pulp prior to ozone delignification |
US5296099A (en) * | 1990-05-17 | 1994-03-22 | Union Camp Holding, Inc. | Environmentally improved process for bleaching lignocellulosic materials with oxygen, ozone and chlorine dioxide |
US5164043A (en) * | 1990-05-17 | 1992-11-17 | Union Camp Patent Holding, Inc. | Environmentally improved process for bleaching lignocellulosic materials with ozone |
US5472572A (en) * | 1990-10-26 | 1995-12-05 | Union Camp Patent Holding, Inc. | Reactor for bleaching high consistency pulp with ozone |
US5181989A (en) * | 1990-10-26 | 1993-01-26 | Union Camp Patent Holdings, Inc. | Reactor for bleaching high consistency pulp with ozone |
US5863389A (en) * | 1990-10-26 | 1999-01-26 | Union Camp Patent Holding, Inc. | Pulp bleaching reactor for dispersing high consistency pulp into a gaseous bleaching agent containing ozone |
US5520783A (en) * | 1990-10-26 | 1996-05-28 | Union Camp Patent Holding, Inc. | Apparatus for bleaching high consistency pulp with ozone |
US5174861A (en) * | 1990-10-26 | 1992-12-29 | Union Camp Patent Holdings, Inc. | Method of bleaching high consistency pulp with ozone |
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 |
US5451296A (en) * | 1991-05-24 | 1995-09-19 | Union Camp Patent Holding, Inc. | Two stage pulp bleaching reactor |
US6007678A (en) * | 1992-11-27 | 1999-12-28 | Eka Nobel Ab | Process for delignification of lignocellulose-containing pulp with an organic peracid or salts thereof |
US5693184A (en) * | 1993-10-01 | 1997-12-02 | Union Camp Patent Holding, Inc. | Reduction of salt scale precipitation by control of process stream pH and salt concentration |
US5554259A (en) * | 1993-10-01 | 1996-09-10 | Union Camp Patent Holdings, Inc. | Reduction of salt scale precipitation by control of process stream Ph and salt concentration |
US5736004A (en) * | 1995-03-03 | 1998-04-07 | Union Camp Patent Holding, Inc. | Control scheme for rapid pulp delignification and bleaching |
US5672247A (en) * | 1995-03-03 | 1997-09-30 | Union Camp Patent Holding, Inc. | Control scheme for rapid pulp delignification and bleaching |
USH1690H (en) * | 1995-07-20 | 1997-11-04 | Nye; Jeffrey | Process for bleaching kraft pulp |
Also Published As
Publication number | Publication date |
---|---|
SE8101772L (sv) | 1981-10-16 |
AU6957881A (en) | 1981-10-22 |
NO811305L (no) | 1981-10-16 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
CA1154205A (en) | Brightness improvement of ozone bleached pulps | |
US4372812A (en) | Chlorine free process for bleaching lignocellulosic pulp | |
US5296099A (en) | Environmentally improved process for bleaching lignocellulosic materials with oxygen, ozone and chlorine dioxide | |
AU638017B2 (en) | Environmentally improved process for bleaching lignocellulosic materials | |
US5164043A (en) | Environmentally improved process for bleaching lignocellulosic materials with ozone | |
US5211811A (en) | Process for high consistency oxygen delignification of alkaline treated pulp followed by ozone delignification | |
CA2102713A1 (en) | Process for bleaching of lignocellulose-containing material | |
US5770010A (en) | Pulping process employing nascent oxygen | |
US5188708A (en) | Process for high consistency oxygen delignification followed by ozone relignification | |
CA2363793A1 (en) | Method to improve pulp yield and bleachability of lignocellulosic pulps | |
FI105213B (fi) | Menetelmä valkaistun massan valmistamiseksi lignoselluloosamateriaalista | |
WO1992012288A1 (en) | Split alkali addition for high consistency oxygen delignification | |
WO1996013634A1 (en) | Process for delignification and bleaching of chemical wood pulps | |
US5389201A (en) | Bleaching of kraft cellulosic pulp employing ozone and reduced consumption of chlorine containing bleaching agent | |
US5441603A (en) | Method for chelation of pulp prior to ozone delignification | |
WO1992017639A1 (en) | Method for reducing colored matter from bleach effluent using a dzd bleach sequence | |
WO1996002697A1 (en) | Improved bleaching of high consistency lignocellulosic pulp | |
CA2036173C (en) | Process for the chlorine-free bleaching and delignification of cellulose | |
AU671159B2 (en) | Improved bleaching of high consistency lignocellulosic pulp | |
EP0720676A1 (en) | Improved method for bleaching lignocellulosic pulp | |
HU216143B (hu) | Eljárás nyers cellulóz ligninmentesítésére | |
WO1996033308A1 (en) | Pulping process | |
JPH04308292A (ja) | 脱墨パルプ含有クラフトパルプの漂白パルプ化法 | |
JPH04222286A (ja) | リグノセルロース物質の漂白方法 | |
CA2258443A1 (en) | Pulp bleaching process including final stage brightening step with salt of peroxymonosulfuric acid |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
MKEX | Expiry | ||
MKEX | Expiry |
Effective date: 20000927 |