EP1611281B1 - Purification of alkaline washing liquid - Google Patents
Purification of alkaline washing liquid Download PDFInfo
- Publication number
- EP1611281B1 EP1611281B1 EP04725953A EP04725953A EP1611281B1 EP 1611281 B1 EP1611281 B1 EP 1611281B1 EP 04725953 A EP04725953 A EP 04725953A EP 04725953 A EP04725953 A EP 04725953A EP 1611281 B1 EP1611281 B1 EP 1611281B1
- Authority
- EP
- European Patent Office
- Prior art keywords
- washer
- flow
- part flow
- pulp
- filtrate
- 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 - Lifetime
Links
- 238000005406 washing Methods 0.000 title claims abstract description 40
- 239000007788 liquid Substances 0.000 title claims abstract description 30
- 238000000746 purification Methods 0.000 title description 2
- 238000000034 method Methods 0.000 claims abstract description 69
- 239000000706 filtrate Substances 0.000 claims abstract description 34
- 229920002678 cellulose Polymers 0.000 claims abstract description 10
- 239000001913 cellulose Substances 0.000 claims abstract description 10
- QAOWNCQODCNURD-UHFFFAOYSA-L Sulfate Chemical compound [O-]S([O-])(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-L 0.000 claims abstract description 9
- 229910052751 metal Inorganic materials 0.000 claims abstract description 9
- 239000002184 metal Substances 0.000 claims abstract description 9
- 150000002739 metals Chemical class 0.000 claims abstract description 9
- 229910021653 sulphate ion Inorganic materials 0.000 claims abstract description 9
- 239000002535 acidifier Substances 0.000 claims abstract description 5
- 239000010802 sludge Substances 0.000 claims abstract description 4
- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical class O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 claims description 16
- 239000000126 substance Substances 0.000 claims description 16
- 229910002092 carbon dioxide Inorganic materials 0.000 claims description 9
- 239000001569 carbon dioxide Substances 0.000 claims description 9
- 230000003247 decreasing effect Effects 0.000 claims description 6
- 239000002253 acid Substances 0.000 claims description 5
- 238000005188 flotation Methods 0.000 claims description 4
- 150000007513 acids Chemical class 0.000 claims description 3
- 239000003795 chemical substances by application Substances 0.000 claims description 3
- 238000005189 flocculation Methods 0.000 claims description 3
- 230000016615 flocculation Effects 0.000 claims description 3
- 229910052500 inorganic mineral Inorganic materials 0.000 claims description 3
- 239000011707 mineral Chemical class 0.000 claims description 3
- 238000004064 recycling Methods 0.000 claims description 3
- 230000015271 coagulation Effects 0.000 claims description 2
- 238000005345 coagulation Methods 0.000 claims description 2
- 230000001627 detrimental effect Effects 0.000 description 9
- 230000009467 reduction Effects 0.000 description 5
- 238000006243 chemical reaction Methods 0.000 description 4
- 229920005610 lignin Polymers 0.000 description 4
- 239000000835 fiber Substances 0.000 description 3
- 238000004519 manufacturing process Methods 0.000 description 3
- 230000007935 neutral effect Effects 0.000 description 3
- 230000029219 regulation of pH Effects 0.000 description 3
- OYPRJOBELJOOCE-UHFFFAOYSA-N Calcium Chemical compound [Ca] OYPRJOBELJOOCE-UHFFFAOYSA-N 0.000 description 2
- 230000002378 acidificating effect Effects 0.000 description 2
- 229910052791 calcium Inorganic materials 0.000 description 2
- 239000011575 calcium Substances 0.000 description 2
- 235000014113 dietary fatty acids Nutrition 0.000 description 2
- 239000000194 fatty acid Substances 0.000 description 2
- 229930195729 fatty acid Natural products 0.000 description 2
- 150000004665 fatty acids Chemical class 0.000 description 2
- 235000018185 Betula X alpestris Nutrition 0.000 description 1
- 235000018212 Betula X uliginosa Nutrition 0.000 description 1
- 229920001131 Pulp (paper) Polymers 0.000 description 1
- 229940095602 acidifiers Drugs 0.000 description 1
- 239000003513 alkali Substances 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 230000020477 pH reduction Effects 0.000 description 1
- 238000001556 precipitation Methods 0.000 description 1
- 230000006798 recombination Effects 0.000 description 1
- 238000005215 recombination Methods 0.000 description 1
- 239000002351 wastewater Substances 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
Images
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
- D21C9/02—Washing ; Displacing cooking or pulp-treating liquors contained in the pulp by fluids, e.g. wash water or other pulp-treating agents
-
- 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
- D21C11/00—Regeneration of pulp liquors or effluent waste waters
-
- 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
- D21C3/00—Pulping cellulose-containing materials
- D21C3/02—Pulping cellulose-containing materials with inorganic bases or alkaline reacting compounds, e.g. sulfate processes
Definitions
- the invention relates to a method for washing an alkaline liquid. More specifically, the invention relates to a method for removing extractives and metals from an alkaline liquid in the washing department of a sulphate cellulose mill.
- FI patent specification 52876 discloses a second method.
- This method comprises washing of cellulose pulp in a multi-stage washing plant, the pH of the pulp being decreased by acidification of the washing liquid for enhanced washing effect.
- the method has the purposes of brightened waste water, reduced effervescence at the screen level and an enhanced brightness degree of unbleached paper grades. This method also results in a low overall pH value and in the occurrence of undesired reactions in the pulp.
- the method of the invention allows more efficient washing of sulphate cellulose pulp and efficient removal of extractives and metals without the pH level of the main flow being too much decreased and without causing other problems in the process.
- the method of the invention is characterised by the features defined in the characterising part of the independent claim.
- the pH regulation of the alkaline filtrate proper can be carried out e.g. using carbon dioxide (CO 2 ) or mineral acids.
- CO 2 carbon dioxide
- mineral acids mineral acids
- Figure 1 shows a first pulp flow 1, which reaches a first washer 101.
- a second pulp flow 2 starts from the first washer 101 to the second washer 102, which may be the last brown mechanical pulp washer or any other washer of the washing department.
- the method is also applicable to more than one washer in a washing department.
- the second pulp flow 2 is a combination of the first pulp flow 1 and the liquid 12 from the process unit 103, which are combined in washer 101.
- the liquid 12 will act as the washing liquid of the first washer 101.
- a washing liquid 3 will also enter the second washer 102, this washing liquid being combined with the second pulp flow 2 coming from the first washer 101.
- the alkaline filtrate displaced by the washing liquid 3 in the second washer 102 is separated from the second pulp flow 2 and the washed third pulp flow 5 is removed by proceeding in the process. If necessary, the pulp flow 5 can be subjected to any further treatment. If the alkaline filtrate 4 contains a large amount of fibres, the filtrate is advantageously filtrated before any further treatment in order to minimise fibre losses.
- the alkaline filtrate 4 separated from the washed second pulp flow 2 in the second washer 102 is divided into two part flows 6 and 7.
- the alkaline filtrate 4 may be divided into e.g. 2/3 first part flows 6 and 1/3 second part flow 7.
- the second part flow 7 of alkaline filtrate 4 is further treated in the process by combining it with an acidifier 8, such as e.g. carbon dioxide (CO 2 ) in order to drop the pH of the part flow.
- the pH of the second part flow 7 of the filtrate 4 can be dropped e.g. to 7 (neutral pH), which is optimal with a view to further treatment of the part flow 7.
- the part flow 9 treated with carbon dioxide is taken to process unit 103.
- the use of carbon dioxide in pH regulation does not alter the chemical balance of the process. Instead of carbon dioxide, one could use e.g. mineral acids as acidifiers.
- the first part flow 6 of the alkaline filtrate 4 proceeds untreated in the process.
- the filtrate 4 from the washer 102 can be divided into part flows 6 and 7 also in any other ratio than 2:1 as above, e.g. 5:1, 4:1, 3:1 or 1:1.
- the division into part flows 6 and 7 in the process has a direct impact on the amount of sludge 10 to be removed and thus of detrimental substances.
- process unit 103 extractives, metals and other detrimental substances are removed from part flow 9 with the use of any methods known per se (coagulation, flocculation, flotation or the like).
- any methods known per se coagulation, flocculation, flotation or the like.
- the sludge 10 produced during the treatment, which contains the detrimental substances, is removed from process unit 103.
- the purified part flow 11 is combined after process unit 103 with the first part flow 6 of the alkaline filtrate 4, producing washing liquid 12, which is taken to washer 101.
- the liquid produced by recombination of the first part flow 6 and the second part flow 7 of the alkaline filtrate 4 is consequently recycled to the process and it is used as the washing liquid 12 of the first washer.
- washing liquid 12 to the pulp flow 1 in washer 101 does not drop the pH of the pulp flow substantially nor does it cause problems, such as undesired reactions of residual lignin.
- washing liquid 12 displaces filtrate 13 in washer 101, and filtrate 13 can be treated in a manner similar to that of filtrate 4 of washer 102, if desired.
- FIG. 2 shows an example of a preferred option of washing sulphate cellulose pulp.
- the pulp flow 2 reaching the washer 102 is illustrated with fibres 21 and liquid 22 as separate parts.
- the pulp flow 2 entering washer 102 contains 6.80/Adt of substances to be removed.
- the filtrate 4 displaced by the washing agent from washer 102 contains 4.20 kg/Adt of substances to be eliminated and the washed pulp flow 5 2.60 kg/Adt accordingly.
- the fibres of the pulp flow 5 then contains about 0.28% of extractives.
- 1/3 of the filtrate is treated in process unit 103, the liquid 9 reaching this unit containing 1.388 kg/Adt of substances to be removed. After the treatment, 75% of the substances reaching the process unit 103 are removed from the process, i.e.
- the washing liquid 12 of washer 101 contains 3.16 kg/Adt of detrimental substances.
- the reduction percentages were 86% for fatty acid, 66% for resinoic acid, 69% for calcium and 75% for magnanium.
- the reduction percentages have been calculated on the part flow passing through process unit 103 (incoming flow 9 and outgoing flow 11) with the flotation method used for purification in the process unit.
- the purpose of the method exemplified above is to maintain the pH of the pulp main flow and to remove detrimental substances from the process merely by dropping the pH of a part flow of the filtrate to a low level, and to recycle the purified filtrate to the main flow. Dropping the pH of a small part flow alone does not have a substantial impact on the pH value of the entire pulp flow, and hence it is possible to avoid problems relating e.g. to residual lignin occurring in known methods.
Landscapes
- Life Sciences & Earth Sciences (AREA)
- Engineering & Computer Science (AREA)
- Wood Science & Technology (AREA)
- Paper (AREA)
- Physical Water Treatments (AREA)
- Cleaning Or Drying Semiconductors (AREA)
- Cleaning And De-Greasing Of Metallic Materials By Chemical Methods (AREA)
- Detergent Compositions (AREA)
- Polysaccharides And Polysaccharide Derivatives (AREA)
Abstract
Description
- The invention relates to a method for washing an alkaline liquid. More specifically, the invention relates to a method for removing extractives and metals from an alkaline liquid in the washing department of a sulphate cellulose mill.
- In the production of sulphate cellulose pulp, new fibre lines with voluminous outputs have involved the problem of the detrimental effect of substances derived from pitch and various metals on pulp production as fibre lines are increasingly closed and water amounts decreased. Extractives cause detrimental adhesions to the equipment surfaces. Substances derived from pitch also cause runnability and quality problems in paper and board machines. Under propitious conditions, some metals form deposits and are thus harmful to the pulp production process.
- It is previously known that extractives and metals can be removed by flocculation or precipitation. These known methods have more efficient operation in neutral or acidic conditions. However, dropping the pH to the neutral or acidic range during the washing of sulphate cellulose pulp results in undesired reactions of residual lignin, and these hamper practical implementation of known methods.
- There are several known methods for washing an alkaline liquid. One of these is disclosed in WO patent specification 88/04705. This specification discloses washing of alkaline fibrous pulp in several steps and dropping the pH in at least one wash step to a level low enough for the detrimental substances to be removed from the fibrous pulp by means of any known method. However, the method disclosed in this reference involves the undesired reactions caused by the pH drop of the pulp mentioned above.
- FI patent specification 52876 discloses a second method. This method comprises washing of cellulose pulp in a multi-stage washing plant, the pH of the pulp being decreased by acidification of the washing liquid for enhanced washing effect. The method has the purposes of brightened waste water, reduced effervescence at the screen level and an enhanced brightness degree of unbleached paper grades. This method also results in a low overall pH value and in the occurrence of undesired reactions in the pulp.
- The method of the invention allows more efficient washing of sulphate cellulose pulp and efficient removal of extractives and metals without the pH level of the main flow being too much decreased and without causing other problems in the process. The method of the invention is characterised by the features defined in the characterising part of the independent claim.
- The advantages mentioned above are achieved by dividing the alkaline filtrate into two part flows, the pH level of one of these being dropped to the optimal level in terms of extractive and metal removal, and by recycling the purified part flow into the process. This maintains the pH level of the main flow at an adequately high level and the problems mentioned above do not occur. The division of this alkaline filtrate into part flows is most advantageously performed with the filtrates from the last steps of the washing department, these filtrates having low residual lignin and alkali concentrations.
- The pH regulation of the alkaline filtrate proper can be carried out e.g. using carbon dioxide (CO2) or mineral acids. The use of carbon dioxide in pH regulation of a part flow does not alter the chemical balance of the process.
- Preferred embodiments of the invention are characterised by the features defined in the claims below.
- The invention is explained in greater detail below by means of examples and with reference to the figures, in which
- Figure 1 is a flow chart of the process,
- Figure 2 is a schematic view of the pulp flow division in the process of figure 1, and
- Figure 3 is a table of the reductions achieved with the method.
- Figure 1 shows a
first pulp flow 1, which reaches afirst washer 101. Asecond pulp flow 2 starts from thefirst washer 101 to thesecond washer 102, which may be the last brown mechanical pulp washer or any other washer of the washing department. The method is also applicable to more than one washer in a washing department. - The
second pulp flow 2 is a combination of thefirst pulp flow 1 and theliquid 12 from theprocess unit 103, which are combined inwasher 101. Thus theliquid 12 will act as the washing liquid of thefirst washer 101. - A washing liquid 3 will also enter the
second washer 102, this washing liquid being combined with thesecond pulp flow 2 coming from thefirst washer 101. The alkaline filtrate displaced by the washing liquid 3 in thesecond washer 102 is separated from thesecond pulp flow 2 and the washedthird pulp flow 5 is removed by proceeding in the process. If necessary, thepulp flow 5 can be subjected to any further treatment. If thealkaline filtrate 4 contains a large amount of fibres, the filtrate is advantageously filtrated before any further treatment in order to minimise fibre losses. - The
alkaline filtrate 4 separated from the washedsecond pulp flow 2 in thesecond washer 102 is divided into two part flows 6 and 7. Thealkaline filtrate 4 may be divided into e.g. 2/3 first part flows 6 and 1/3second part flow 7. Thesecond part flow 7 ofalkaline filtrate 4 is further treated in the process by combining it with anacidifier 8, such as e.g. carbon dioxide (CO2) in order to drop the pH of the part flow. The pH of thesecond part flow 7 of thefiltrate 4 can be dropped e.g. to 7 (neutral pH), which is optimal with a view to further treatment of thepart flow 7. Next thepart flow 9 treated with carbon dioxide is taken to processunit 103. The use of carbon dioxide in pH regulation does not alter the chemical balance of the process. Instead of carbon dioxide, one could use e.g. mineral acids as acidifiers. The first part flow 6 of thealkaline filtrate 4 proceeds untreated in the process. - The
filtrate 4 from thewasher 102 can be divided intopart flows sludge 10 to be removed and thus of detrimental substances. - In
process unit 103, extractives, metals and other detrimental substances are removed frompart flow 9 with the use of any methods known per se (coagulation, flocculation, flotation or the like). When the pH ofpart flow 9 is approx. 7, the optimal situation in terms of e.g. flotation has been achieved inprocess unit 103. Thesludge 10 produced during the treatment, which contains the detrimental substances, is removed fromprocess unit 103. The purifiedpart flow 11 is combined afterprocess unit 103 with thefirst part flow 6 of thealkaline filtrate 4, producingwashing liquid 12, which is taken towasher 101. The liquid produced by recombination of thefirst part flow 6 and thesecond part flow 7 of thealkaline filtrate 4 is consequently recycled to the process and it is used as thewashing liquid 12 of the first washer. Addition ofwashing liquid 12 to thepulp flow 1 inwasher 101 does not drop the pH of the pulp flow substantially nor does it cause problems, such as undesired reactions of residual lignin. Similarly,washing liquid 12 displaces filtrate 13 inwasher 101, andfiltrate 13 can be treated in a manner similar to that offiltrate 4 ofwasher 102, if desired. - Figure 2 shows an example of a preferred option of washing sulphate cellulose pulp. The
pulp flow 2 reaching thewasher 102 is illustrated withfibres 21 andliquid 22 as separate parts. Thepulp flow 2 enteringwasher 102 contains 6.80/Adt of substances to be removed. Thefiltrate 4 displaced by the washing agent fromwasher 102 contains 4.20 kg/Adt of substances to be eliminated and the washedpulp flow 5 2.60 kg/Adt accordingly. The fibres of thepulp flow 5 then contains about 0.28% of extractives. In this example, 1/3 of the filtrate is treated inprocess unit 103, theliquid 9 reaching this unit containing 1.388 kg/Adt of substances to be removed. After the treatment, 75% of the substances reaching theprocess unit 103 are removed from the process, i.e. 1.04 kg/Adt as indicated byarrow 10. The untreated portion 6 (2/3) of thefiltrate 4, which contains 2.814 kg/Adt of detrimental substances, is combined with theportion 11 purified inprocess unit 103 and is recycled to thewasher 101. In this example, thewashing liquid 12 ofwasher 101 contains 3.16 kg/Adt of detrimental substances. - Next follows a practical example of the treatment of an alkaline filtrate of birch pulp at a sulphate cellulose mill with the method of the invention by means of the reduction percentages thus achieved. In the first case, the
part flow 7 offiltrate 4 has been acidified to reduce its pH to 9.4, and in the second case, to 7.0, whereas theoriginal filtrate 4 had a pH > 10. The results achieved with the method of the invention are summarised in the table of figure 3. With pH 9.4 of the liquid, the reduction percentages were 0% for fatty acid, 13% for resinoic acid, 30% for calcium and 21% for magnanium, respectively. Accordingly, with the pH of the liquid dropped to 7.0, the reduction percentages were 86% for fatty acid, 66% for resinoic acid, 69% for calcium and 75% for magnanium. The reduction percentages have been calculated on the part flow passing through process unit 103 (incoming flow 9 and outgoing flow 11) with the flotation method used for purification in the process unit. - The purpose of the method exemplified above is to maintain the pH of the pulp main flow and to remove detrimental substances from the process merely by dropping the pH of a part flow of the filtrate to a low level, and to recycle the purified filtrate to the main flow. Dropping the pH of a small part flow alone does not have a substantial impact on the pH value of the entire pulp flow, and hence it is possible to avoid problems relating e.g. to residual lignin occurring in known methods.
Claims (7)
- A method for washing an alkaline liquid in the washing department of a sulphate cellulose mill, the method comprising the following steps in the order below:- conducting a first pulp flow (1) to a first washer (101), where a washing liquid (12) is combined with the first pulp flow (1),- conducting a second pulp flow (2) from the first washer (101) to a second washer (102), where a washing liquid (3) is combined with the second pulp flow (2),- proceeding the washed pulp flow (5) from the second washer (102) in the process and recycling the filtrate (4) displaced by the washing agent (3) to the process,characterised in- dividing the filtrate (4) displaced by the washing agent (3) from the washer (102) into a first part flow (6) and a second part flow (7),- decreasing the pH of the second part flow (7) by combining an acidifier (8) with the second part flow (7)- conducting the acidified part flow (9) to a process unit (103) where the sludge (10) containing extractives and metals is removed from the part flow (9) and the entire process- combining the part flow (11) treated in the process unit (103) with the first part flow (6) and recycling it to the process for use as the washing liquid (12) of the first washer (101).
- A method as defined in claim 1, characterised in that the filtrate (4) from the washer (102) is divided into a first part flow (6) and a second part flow (7) in the ratio 1:1, 2:1, 3:1, 4:1 or 5:1.
- A method as defined in claim 2, characterised in that the pH of the second part flow (7) of the filtrate (4) is decreased to the range 6 to 8.
- A method as defined in claim 2, characterised in that the pH of the second part flow (7) of the filtrate (4) is decreased to the range 6.5 to 7.5.
- A method as defined in claim 3 or 4, characterised in that carbon dioxide, mineral acids or other similar substances are used as an acidifier (8).
- A method as defined in claim 5, characterised in that the washer (101) is the one before the last and the washer (102) is the last washer.
- A method as defined in claim 6, characterised in that the extractives and metals are removed from the process unit (103) by coagulation, flocculation and flotation or any similar methods.
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
FI20030522A FI115977B2 (en) | 2003-04-07 | 2003-04-07 | Purification of alkaline washing liquid |
PCT/FI2004/000210 WO2004090225A1 (en) | 2003-04-07 | 2004-04-06 | Purification of alkaline washing liquid |
Publications (2)
Publication Number | Publication Date |
---|---|
EP1611281A1 EP1611281A1 (en) | 2006-01-04 |
EP1611281B1 true EP1611281B1 (en) | 2006-12-06 |
Family
ID=8565931
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP04725953A Expired - Lifetime EP1611281B1 (en) | 2003-04-07 | 2004-04-06 | Purification of alkaline washing liquid |
Country Status (8)
Country | Link |
---|---|
US (1) | US20070039702A1 (en) |
EP (1) | EP1611281B1 (en) |
JP (1) | JP2006522235A (en) |
AT (1) | ATE347636T1 (en) |
DE (1) | DE602004003573T2 (en) |
ES (1) | ES2278312T3 (en) |
FI (1) | FI115977B2 (en) |
WO (1) | WO2004090225A1 (en) |
Families Citing this family (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP4825709B2 (en) * | 2007-03-15 | 2011-11-30 | 三菱製紙株式会社 | Foaming and pitch trouble suppression method |
Family Cites Families (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5509999A (en) * | 1993-03-24 | 1996-04-23 | Kamyr, Inc. | Treatment of bleach plant effluents |
US5489363A (en) * | 1993-05-04 | 1996-02-06 | Kamyr, Inc. | Pulping with low dissolved solids for improved pulp strength |
SE9303762L (en) * | 1993-11-15 | 1995-05-16 | Eka Nobel Ab | Ways to purify process water from pulp production |
FI990127A0 (en) * | 1999-01-22 | 1999-01-22 | Ahlstrom Machinery Oy | Process for treating pulp |
SE519342C2 (en) * | 1999-10-25 | 2003-02-18 | Andritz Oy | Pulping process with recirculation of filtrate from washing step, involves temperature conditioning the mixture of soap and filtrate before separating the soap from the filtrate |
US6752903B2 (en) * | 2001-07-27 | 2004-06-22 | Craig A. Bianchini | Method for mitigating the interference caused by high-molecular weight by-products in pulping processes |
-
2003
- 2003-04-07 FI FI20030522A patent/FI115977B2/en not_active IP Right Cessation
-
2004
- 2004-04-06 EP EP04725953A patent/EP1611281B1/en not_active Expired - Lifetime
- 2004-04-06 WO PCT/FI2004/000210 patent/WO2004090225A1/en active IP Right Grant
- 2004-04-06 ES ES04725953T patent/ES2278312T3/en not_active Expired - Lifetime
- 2004-04-06 US US10/552,435 patent/US20070039702A1/en not_active Abandoned
- 2004-04-06 AT AT04725953T patent/ATE347636T1/en active
- 2004-04-06 DE DE602004003573T patent/DE602004003573T2/en not_active Expired - Lifetime
- 2004-04-06 JP JP2006505631A patent/JP2006522235A/en active Pending
Also Published As
Publication number | Publication date |
---|---|
FI115977B (en) | 2005-08-31 |
JP2006522235A (en) | 2006-09-28 |
DE602004003573D1 (en) | 2007-01-18 |
WO2004090225A1 (en) | 2004-10-21 |
EP1611281A1 (en) | 2006-01-04 |
ES2278312T3 (en) | 2007-08-01 |
US20070039702A1 (en) | 2007-02-22 |
ATE347636T1 (en) | 2006-12-15 |
FI20030522A0 (en) | 2003-04-07 |
FI115977B2 (en) | 2019-03-29 |
FI20030522A (en) | 2004-10-08 |
DE602004003573T2 (en) | 2007-09-27 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US5503709A (en) | Environmentally improved process for preparing recycled lignocellulosic materials for bleaching | |
US6569284B1 (en) | Elemental-chlorine-free bleaching process having an initial Eo or Eop stage | |
US5853535A (en) | Process for manufacturing bleached pulp including recycling | |
JPH08503750A (en) | A method for delignification of pulp containing lignocellulose | |
JPH08260371A (en) | Organo-solve pulp containing no chlorine | |
US5234544A (en) | Cleaning and bleaching of secondary fiber | |
JPH08509781A (en) | Pulp bleaching with chlorine-free chemicals | |
EP1611281B1 (en) | Purification of alkaline washing liquid | |
AU665461B2 (en) | Method of treating process water | |
RU2097463C1 (en) | Method of bleaching of delignification lignocellulose-containing pulp | |
US20100175839A1 (en) | Process for adjusting the ph of a cellulosic pulp, production of pulp or paper from cellulosic pulp and use of (bi)carbonate removal for reducing the consumption of acid | |
EP0937173A1 (en) | Prebleaching of paperpulp before a peroxide bleaching stage | |
EP0720676A1 (en) | Improved method for bleaching lignocellulosic pulp | |
EP1311722A1 (en) | Two-stage chlorine bleaching process with filtrate recirculation | |
JP3275271B2 (en) | Bleaching method of chemical pulp | |
Liu et al. | Using Mg (OH) 2 in peroxide bleaching of wheat straw soda-AQ pulp | |
US5700350A (en) | Processes of retaining chelant-containing effluent within pulp bleach plants | |
US5980689A (en) | Method of separating metal ions from pulp using a chelating agent | |
FI122773B (en) | Preparation of pulp | |
JPH05247864A (en) | Bleaching of cellulose pulp | |
SK117593A3 (en) | Process for bleaching of lignocellulose containing pulp | |
AU726599B2 (en) | Treatment of pulp with a chelating agent without using a bleaching tower | |
JP2546224B2 (en) | Method for removing organochlorine compounds in effluent | |
WO1998017857A1 (en) | Removal of metals from treatment fluids in a cellulose pulp mill | |
WO2001073195A1 (en) | Treatment of bleach plant filtrates |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
PUAI | Public reference made under article 153(3) epc to a published international application that has entered the european phase |
Free format text: ORIGINAL CODE: 0009012 |
|
17P | Request for examination filed |
Effective date: 20051014 |
|
AK | Designated contracting states |
Kind code of ref document: A1 Designated state(s): AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HU IE IT LI LU MC NL PL PT RO SE SI SK TR |
|
AX | Request for extension of the european patent |
Extension state: AL HR LT LV MK |
|
RIN1 | Information on inventor provided before grant (corrected) |
Inventor name: PIGG, PASI Inventor name: SONNI, HANNU Inventor name: TOEROENEN, MARJO |
|
GRAP | Despatch of communication of intention to grant a patent |
Free format text: ORIGINAL CODE: EPIDOSNIGR1 |
|
DAX | Request for extension of the european patent (deleted) | ||
GRAS | Grant fee paid |
Free format text: ORIGINAL CODE: EPIDOSNIGR3 |
|
GRAA | (expected) grant |
Free format text: ORIGINAL CODE: 0009210 |
|
AK | Designated contracting states |
Kind code of ref document: B1 Designated state(s): AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HU IE IT LI LU MC NL PL PT RO SE SI SK TR |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: LI Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20061206 Ref country code: SI Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20061206 Ref country code: CH Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20061206 Ref country code: RO Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20061206 Ref country code: NL Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20061206 Ref country code: SK Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20061206 Ref country code: BE Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20061206 Ref country code: CZ Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20061206 Ref country code: DK Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20061206 Ref country code: PL Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20061206 Ref country code: IT Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT;WARNING: LAPSES OF ITALIAN PATENTS WITH EFFECTIVE DATE BEFORE 2007 MAY HAVE OCCURRED AT ANY TIME BEFORE 2007. THE CORRECT EFFECTIVE DATE MAY BE DIFFERENT FROM THE ONE RECORDED. Effective date: 20061206 |
|
REG | Reference to a national code |
Ref country code: GB Ref legal event code: FG4D |
|
REG | Reference to a national code |
Ref country code: CH Ref legal event code: EP |
|
REG | Reference to a national code |
Ref country code: IE Ref legal event code: FG4D |
|
REF | Corresponds to: |
Ref document number: 602004003573 Country of ref document: DE Date of ref document: 20070118 Kind code of ref document: P |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: BG Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20070306 |
|
REG | Reference to a national code |
Ref country code: SE Ref legal event code: TRGR |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: PT Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20070507 |
|
NLV1 | Nl: lapsed or annulled due to failure to fulfill the requirements of art. 29p and 29m of the patents act | ||
PLBI | Opposition filed |
Free format text: ORIGINAL CODE: 0009260 |
|
REG | Reference to a national code |
Ref country code: CH Ref legal event code: PL |
|
ET | Fr: translation filed | ||
26 | Opposition filed |
Opponent name: METSO FIBER KARLSTAD AB Effective date: 20070529 |
|
REG | Reference to a national code |
Ref country code: ES Ref legal event code: FG2A Ref document number: 2278312 Country of ref document: ES Kind code of ref document: T3 |
|
PLAX | Notice of opposition and request to file observation + time limit sent |
Free format text: ORIGINAL CODE: EPIDOSNOBS2 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: GR Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20070307 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: IE Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20070410 |
|
GBPC | Gb: european patent ceased through non-payment of renewal fee |
Effective date: 20080406 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: EE Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20061206 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: MC Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20070430 |
|
PLAY | Examination report in opposition despatched + time limit |
Free format text: ORIGINAL CODE: EPIDOSNORE2 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: GB Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20080406 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: CY Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20061206 Ref country code: LU Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20070406 |
|
PLBC | Reply to examination report in opposition received |
Free format text: ORIGINAL CODE: EPIDOSNORE3 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: TR Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20061206 Ref country code: HU Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20070607 |
|
PLAB | Opposition data, opponent's data or that of the opponent's representative modified |
Free format text: ORIGINAL CODE: 0009299OPPO |
|
R26 | Opposition filed (corrected) |
Opponent name: METSO FIBER KARLSTAD AB Effective date: 20070529 |
|
PLCK | Communication despatched that opposition was rejected |
Free format text: ORIGINAL CODE: EPIDOSNREJ1 |
|
APBM | Appeal reference recorded |
Free format text: ORIGINAL CODE: EPIDOSNREFNO |
|
APBP | Date of receipt of notice of appeal recorded |
Free format text: ORIGINAL CODE: EPIDOSNNOA2O |
|
APAH | Appeal reference modified |
Free format text: ORIGINAL CODE: EPIDOSCREFNO |
|
APBQ | Date of receipt of statement of grounds of appeal recorded |
Free format text: ORIGINAL CODE: EPIDOSNNOA3O |
|
REG | Reference to a national code |
Ref country code: FR Ref legal event code: PLFP Year of fee payment: 13 |
|
REG | Reference to a national code |
Ref country code: FR Ref legal event code: PLFP Year of fee payment: 14 |
|
REG | Reference to a national code |
Ref country code: DE Ref legal event code: R100 Ref document number: 602004003573 Country of ref document: DE |
|
APBU | Appeal procedure closed |
Free format text: ORIGINAL CODE: EPIDOSNNOA9O |
|
PLBN | Opposition rejected |
Free format text: ORIGINAL CODE: 0009273 |
|
STAA | Information on the status of an ep patent application or granted ep patent |
Free format text: STATUS: OPPOSITION REJECTED |
|
27O | Opposition rejected |
Effective date: 20180126 |
|
REG | Reference to a national code |
Ref country code: FR Ref legal event code: PLFP Year of fee payment: 15 |
|
PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: ES Payment date: 20180525 Year of fee payment: 15 Ref country code: FI Payment date: 20180419 Year of fee payment: 15 Ref country code: DE Payment date: 20180420 Year of fee payment: 15 |
|
PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: AT Payment date: 20180419 Year of fee payment: 15 Ref country code: FR Payment date: 20180420 Year of fee payment: 15 |
|
PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: SE Payment date: 20180418 Year of fee payment: 15 |
|
REG | Reference to a national code |
Ref country code: DE Ref legal event code: R119 Ref document number: 602004003573 Country of ref document: DE |
|
REG | Reference to a national code |
Ref country code: SE Ref legal event code: EUG |
|
REG | Reference to a national code |
Ref country code: AT Ref legal event code: MM01 Ref document number: 347636 Country of ref document: AT Kind code of ref document: T Effective date: 20190406 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: AT Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20190406 Ref country code: SE Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20190407 Ref country code: DE Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20191101 Ref country code: FI Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20190406 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: FR Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20190430 |
|
REG | Reference to a national code |
Ref country code: ES Ref legal event code: FD2A Effective date: 20200828 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: ES Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20190407 |