CN102363929A - Method for improving hydrogen peroxide bleaching efficiency of paper pulp - Google Patents
Method for improving hydrogen peroxide bleaching efficiency of paper pulp Download PDFInfo
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- CN102363929A CN102363929A CN2011103883510A CN201110388351A CN102363929A CN 102363929 A CN102363929 A CN 102363929A CN 2011103883510 A CN2011103883510 A CN 2011103883510A CN 201110388351 A CN201110388351 A CN 201110388351A CN 102363929 A CN102363929 A CN 102363929A
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Abstract
The invention discloses a method for improving hydrogen peroxide bleaching efficiency of paper pulp, and belongs to the technical field of pulp preparation and papermaking. According to the method, a urea active agent and a chelating agent are simultaneously added in the alkali hydrogen peroxide bleaching process of chemical mechanical pulp or waste paper ink removed pulp, the consumption of the urea is 2.0 to 20 kilograms per ton of pulp, the consumption of ethylene diamine tetraacetic acid (EDTA) or diethylenetriamine pentaacetic acid (DTPA) serving as the chelating agent is 1 to 10 kilograms per ton of pulp, and hydrogen peroxide, sodium hydroxide and sodium silicate are simultaneously added during bleaching. In the alkali hydrogen peroxide bleaching process of the paper pulp, the urea serving as the active agent is added at the same time of adding the chelating agent, so that the hydrogen peroxide bleaching efficiency can be improved. Compared with a method without adding the urea serving as the active agent during bleaching, the method has the advantages that: the whiteness of the bleached pulp is obviously improved after the urea is added during bleaching, and the physical strength of the bleached pulp is basically as same as that of the pulp when the urea is not added.
Description
Technical field
The present invention relates to a kind of association with pulp bleaching technology, specifically is a kind of method that improves chemi-mechanical pulp and pulp from decoloured waste paper hydrogen peroxide bleaching efficiency, belongs to the pulp and paper technology field.
Background technology
High yield pulps such as chemi-mechanical pulp are because yield is high, production cost is low, and have advantages such as high opacity, bulk and deflection, in paper production, use more and more.In addition, in order to economize in raw materials, the use of pulp from decoloured waste paper is also more and more.At present high yield pulp such as chemi-mechanical pulp is starched bleaching process with deinking and is mainly adopted hydrogen peroxide bleaching, will add NaOH, sodium metasilicate etc. in the hydrogen peroxide bleaching process simultaneously, and bleaching is carried out under alkali condition.In paper pulp hydrogen peroxide bleaching process; Make paper pulp reach higher whiteness, then need higher hydrogen peroxide consumption, and when the whiteness of paper pulp acquires a certain degree; The consumption that continues the increase hydrogen peroxide is also not obvious to the raising of the whiteness of paper pulp, causes the bleaching efficiency of hydrogen peroxide low.
In paper pulp hydrogen peroxide bleaching process, many researcher's researchs add chemical assistant to improve the bleaching efficiency of hydrogen peroxide in bleaching process.In hydrogen peroxide bleaching, add of the invalid decomposition of chelating agents such as ethylenediamine tetra-acetic acid (EDTA), diethyl pentetic acid (DTPA) or sodium phosphate trimer the earliest exactly, improve the bleaching efficiency of hydrogen peroxide with the hydrogen peroxide of minimizing heavy metal ion catalysis.In addition, other many chemical assistants also are used to improve the bleaching efficiency of hydrogen peroxide as Activator of Peroxide Bleaching.Deng Yu and Feng Jianmin etc. are used for wheat straw chemical pulp hydrogen peroxide bleaching process with tetraacetyl ethylene diamine (TAED); The result shows; TAED can the activation hydrogen peroxide, and (referring to Deng Yu, Feng Jianmin, tetraacetyl ethylene diamine (TAED) is to the activation of paper pulp hydrogen peroxide bleaching to improve the bleaching effect of hydrogen peroxide; Southwest papermaking, 34 (1): 33 (2005)).People such as Cui Yu are used for the hydrogen peroxide bleaching of chemical pulp with a kind of double-core manganese complex, find that the double-core manganese complex can the activation hydrogen peroxide, and the bleaching effect that improves hydrogen peroxide is (referring to people such as Cui Yu; The sulfate of Mn (IV)-Me4DTNE catalysis-fear quinone pine slurry hydrogen peroxide bleaching dynamics research, timber is studied, and 54 (4): 413; 2000 (Yu Cui, Pratuang Puthson, Chen-Loung Chen et al.; Kinetic Study on Delignification of Kraft-AQ Pine Pulp with Hydrogen Peroxide Catalyzed by Mn (IV)-Me4DTNE; Holzforschung, 54 (4): 413,2000)).People's such as Zhao Jian research shows that molybdate can improve the acidic hydrogen peroxide bleaching effect that Eucalyptus oxygen floats NBSK effectively, but the viscosity of paper pulp decreases after the bleaching (build referring to Zhao, Shi Shulan and Hu Huiren etc., molybdate is to Eucalyptus KP slurry H
2O
2Bleaching improve effect, Chinese papermaking, 20 (1): 18,2001).Liang Fuzheng etc. are used for the hydrogen peroxide bleaching of kenaf whole stalk high yield pulp with dicyandiamide, and the result shows that dicyandiamide can be purchased the activation hydrogen peroxide, and (referring to Liang Fuzheng etc., several kinds of auxiliary agents are at the full stalk high yield pulp H of bluish dogbane to improve paper pulp hydrogen peroxide bleaching effect
2O
2Application in the bleaching, Heilungkiang papermaking, 4:5,2007).
Urea also has application as industrial a kind of common chemicals in pulping and papermaking processes.As in the chemical pulp digestion process, can add the performance that urea improves paper pulp.Santiago etc. add urea in Eucalyptus NBSK digestion process, the result shows in the boiling and to add the yield that urea can improve paper pulp.(, estimate the potential method that improves Eucalyptus sulfate pulp-making yield, chemistry and biotechnology, 82 (5): 424,2007 referring to people such as Santiago.(Santiago?A.S.，Pascoal?Neto?C.P.，Assessment?of?potential?approaches?to?improve?Eucalyptus?globulus?kraft?pulping?yield，Journal?of?Chemical?Technology?and?Biotechnology，82(5)：424，2007))。Tang Fenghua etc. add the urea preliminary treatment before poplar NBSK oxygen floats, the oxygen that discovery can improve paper pulp floats effect, and when in the hydrogen peroxide bleaching section, directly adding urea; Can not strengthen significantly hydrogen peroxide bleaching effect (referring to Tang Fenghua, Zhang Yunzhan, the State of Lu; Novel bleaching assistant-urea; International Paper, 22 (2): 22,2003).
US 4274912 (A) discloses the method for the high whiteness bleaching of a kind of NBSK.Mainly comprise step: 1. paper pulp is carried out chlorination with chlorine under 35 ℃-50 ℃, add urea during chlorination, time of chlorinating 30 seconds-45 minutes with respect to chlorine consumption 0.5-5%; 2. in the presence of oxidants such as hypochlorite or hydrogen peroxide, carry out the alkali extracting, pH value 8-12; 3. use chlorine dioxide treatment, pH5-9 down for 60 ℃-90 ℃.The waste water circulation in second step and/or the 3rd step is used for the middle washing of paper pulp.This invention technology can be floated paper pulp to very high whiteness, under the prerequisite that does not reduce pulp quality, reduces and pollutes.
Hydrogen peroxide is widely used in the bleaching of paper pulp at present; But if make paper pulp reach higher whiteness, then the consumption of hydrogen peroxide is high, after pulp brightness acquires a certain degree; Increase the raising DeGrain of the consumption of hydrogen peroxide, cause the bleaching efficiency of hydrogen peroxide low whiteness.For improving the bleaching efficiency of paper pulp hydrogen peroxide, in bleaching, can add chelating agents such as EDTA and DTPA to remove heavy metal ion, reduce the invalid decomposition of hydrogen peroxide.In the kraft bleaching process, adding auxiliary agent such as cyanamide, molybdate wait the activation hydrogen peroxide, improve the bleaching effect of hydrogen peroxide.In the bleaching of high yield pulp and deinking slurry, tetraacetyl ethylene diamine (TAED) can be used for improving the bleaching efficiency of hydrogen peroxide, but because the cost of these auxiliary agents is high, has limited its application in actual production.In the hydrogen peroxide bleaching process of high yield pulp and deinking slurry, also do not add the method that chelating agent and activator urea improve hydrogen peroxide bleaching efficiency, improve pulp brightness simultaneously at present.
China's chemi-mechanical pulp (like CTMP (CTMP) and mill preliminary treatment APMP (PRC-APMP)) and the production and the use amount of pulp from decoloured waste paper constantly increase at present; And the hydrogen peroxide bleaching that keeps the lignin formula is mainly adopted in the bleaching of chemi-mechanical pulp and deinking slurry; Therefore; Improve the bleaching efficiency of hydrogen peroxide, for the whiteness of improving paper pulp, reducing production costs has great importance.
Summary of the invention
The present invention is directed to chemi-mechanical pulp and the low problem of pulp from decoloured waste paper hydrogen peroxide bleaching efficiency, a kind of new method of improving hydrogen peroxide bleaching efficiency, improving pulp brightness is provided.When the paper pulp hydrogen peroxide bleaching, add activator simultaneously and chelating agent is bleached, activator adopts urea, and chelating agent refers to EDTA or DTPA or their combination.Employing the present invention can improve the bleaching efficiency of hydrogen peroxide, improves the bleaching effect of paper pulp, improves the whiteness of paper pulp, keeps the physical strength of paper pulp simultaneously.
The method and technology scheme that the present invention improves the paper pulp hydrogen peroxide bleaching efficiency is: in chemi-mechanical pulp or pulp from decoloured waste paper hydrogen peroxide bleaching process, when adding chelating agent, add activator urea; Amount of urea is 2.0～20kg/ ton slurry; Amount of chelant 1～10kg/ ton slurry adds H simultaneously during bleaching
2O
210～80kg/ ton slurry, NaOH 10～40kg/ ton slurry, sodium metasilicate 10～40kg/ ton slurry; Said pulp density is 8～35wt%, and bleaching temperature is 60～90 ℃, bleaching time 1.0～4h.
Described paper pulp is that needlebush, leaf wood chemi-mechanical pulp or both mix the chemi-mechanical pulp and the pulp from decoloured waste paper of production, and chemi-mechanical pulp comprises CTMP (CTMP) and mill preliminary treatment APMP (PRC-APMP).CTMP refers to the CTMP that do not float behind second section defibrination; Mill preliminary treatment APMP refers to first section brown stock behind the defibrination.Pulp from decoloured waste paper comprises that crushed news deinking slurry, deinking office waste paper slurry and Mixed Office WasteMOW deinking slurry and crushed news mix the deinking slurry of producing with magazine paper.Said chelating agent refers to EDTA, DTPA or their combination.
Urea of the present invention and chelating agent add in paper pulp hydrogen peroxide bleaching process.In the existing paper pulp hydrogen peroxide bleaching technology, be primarily aimed at hydrogen peroxide bleaching section in the NBSK multistage bleaching and add auxiliary agent such as activation hydrogen peroxide such as dicyandiamide, tetraacetyl ethylene diamine (TAED) or urea to improve the bleaching efficiency of hydrogen peroxide.And comprise in the hydrogen peroxide bleaching process of CTMP and PRC-APMP and deinking slurry at high yield pulp, generally only adopt chelating agent such as EDTA or DTPA to come the chelating heavy metal ion to reduce the invalid decomposition of hydrogen peroxide, improve the bleaching efficiency of hydrogen peroxide.When paper pulp being floated to higher whiteness, need the hydrogen peroxide consumption high, the bleaching efficiency of hydrogen peroxide is low.
Compared with prior art, excellent results of the present invention is following: in existing chemi-mechanical pulp and the deinking slurry alkaline hydrogen peroxide bleaching process, when not adding activator, hydrogen peroxide bleaching efficiency is lower.The present invention adds activator urea and chelating agent simultaneously in paper pulp alkaline hydrogen peroxide bleaching process, improve the bleaching efficiency of hydrogen peroxide.The adding of chelating agent can reduce the invalid decomposition of hydrogen peroxide, and the adding of activator urea can the activation hydrogen peroxide, generates the ion or the group that help bleaching, so the synergy of chelating agent and activator improves the bleaching efficiency of hydrogen peroxide significantly.Adopt the bleaching effect of paper pulp hydrogen peroxide after the technology of the present invention to improve, can reduce the hydrogen peroxide consumption, reduce production costs, perhaps under identical hydrogen peroxide consumption, obtain the higher paper pulp of whiteness, keep the physical strength of paper pulp simultaneously.In addition, residual urea can be used as the nitrogenous source that wastewater biochemical is handled in bleaching effluent, easily biological-degradable, and can reduce replenishing of nitrogenous source in the wastewater biochemical processing procedure (like urea).
The specific embodiment
Below in conjunction with embodiment the present invention is done further explanation, but be not limited thereto.
Embodiment 1:
Brown stock behind first section defibrination of poplar PRC-APMP, whiteness 54%ISO, in polyethylene plastic bag and be put in and carry out hydrogen peroxide bleaching in the water-bath, the bleaching medicine of adding is following: urea 10kg/ ton slurry, DTPA 1.5kg/ ton slurry, H
2O
250kg/ ton slurry, NaOH 25kg/ ton slurry, sodium metasilicate 30kg/ ton slurry, pulp density 30wt%, 85 ℃ of bleaching temperatures, bleaching time 2.0h, bleaching back pulp brightness 82%ISO.In bleaching process, do not add urea, when other medicines were all identical, the whiteness of gained bleached pulp was 80%ISO.The physical strength that adds the bleached pulp of gained behind the urea in the bleaching is basic identical with the control slurry that does not add urea.
Embodiment 2:
Poplar CTMP brown stock, whiteness 52%ISO, in polyethylene plastic bag and be put in and carry out hydrogen peroxide bleaching in the water-bath, the bleaching medicine of adding is following: urea 15kg/ ton slurry, EDTA 5kg/ ton slurry, H
2O
240kg/ ton slurry, NaOH 20kg/ ton slurry, sodium metasilicate 20kg/ ton slurry, pulp density 25wt%, 80 ℃ of bleaching temperatures, bleaching time 2.0h, bleaching back pulp brightness 79%ISO.In bleaching process, do not add urea, when other medicines were all identical, the whiteness of gained bleached pulp was 76.8%ISO.The physical strength that adds the bleached pulp of gained behind the urea in the bleaching is basic identical with the control slurry that does not add urea.
Embodiment 3:
Pine CTMP brown stock, whiteness 48%ISO, in polyethylene plastic bag and be put in and carry out hydrogen peroxide bleaching in the water-bath, the bleaching medicine of adding is following: urea 15kg/ ton slurry, EDTA 5kg/ ton slurry, H
2O
250kg/ ton slurry, NaOH 24kg/ ton slurry, sodium metasilicate 18kg/ ton slurry, pulp density 25wt%, 75 ℃ of bleaching temperatures, bleaching time 2.0h, bleaching back pulp brightness 75%ISO.In bleaching process, do not add urea, when other medicines were all identical, the whiteness of gained bleached pulp was 73%ISO.The physical strength that adds the bleached pulp of gained behind the urea in the bleaching is basic identical with the control slurry that does not add urea.
Embodiment 4:
Crushed news deinking slurry, whiteness 54%ISO, in polyethylene plastic bag and be put in and carry out hydrogen peroxide bleaching in the water-bath, the bleaching medicine of adding is following: urea 5kg/ ton slurry, DTPA 1.5kg/ ton slurry, H
2O
220kg/ ton slurry, NaOH 15kg/ ton slurry, sodium metasilicate 20kg/ ton slurry, pulp density 15wt%, 70 ℃ of bleaching temperatures, bleaching time 1.5h, bleaching back pulp brightness 59%ISO.In bleaching process, do not add urea, when other medicines were all identical, the whiteness of gained bleached pulp was 57.4%ISO.The physical strength that adds the bleached pulp of gained behind the urea in the bleaching is basic identical with the control slurry that does not add urea.
Embodiment 5: like embodiment 1, different is that the paper pulp that adopts is the brown stock behind first section defibrination of Eucalyptus PRC-APMP.
Embodiment 6: like embodiment 2, different is that the paper pulp that adopts is Eucalyptus CTMP brown stock.
Embodiment 7: like embodiment 1, the chelating agent that adds when different is bleaching is EDTA3.0kg/ ton slurry and DTPA1.0kg/ ton slurry.
Embodiment 8: like embodiment 2, the urea that adds when different is bleaching is 10kg/ ton slurry.
Embodiment 9: like embodiment 1, different is that the paper pulp that adopts is the brown stock 80% poplar mixes first section defibrination of PRC-APMP of producing with 20% pine after.
Embodiment 10: like embodiment 3, different is that the paper pulp that adopts is Mixed Office WasteMOW deinking slurry.
Claims (3)
1. method that improves the paper pulp hydrogen peroxide bleaching efficiency; It is characterized in that; In chemi-mechanical pulp or pulp from decoloured waste paper hydrogen peroxide bleaching process, when adding chelating agent, add activator urea; Amount of urea is 2.0～20kg/ ton slurry, and amount of chelant 1～10kg/ ton slurry adds H simultaneously during bleaching
2O
210～80kg/ ton slurry, NaOH 10～40kg/ ton slurry, sodium metasilicate 10～40kg/ ton slurry; Said pulp density is 8～35wt%, and bleaching temperature is 60～90 ℃, and bleaching time is 1.0～4h.
2. a kind of method that improves the paper pulp hydrogen peroxide bleaching efficiency as claimed in claim 1 is characterized in that, said chemi-mechanical pulp is that needlebush chemi-mechanical pulp, leaf wood chemi-mechanical pulp or both mix the chemi-mechanical pulp of production; Said pulp from decoloured waste paper is that crushed news deinking slurry, deinking office waste paper slurry, Mixed Office WasteMOW deinking slurry or crushed news mix the deinking slurry of producing with magazine paper; Said chelating agent is EDTA, DTPA or their combination.
3. according to claim 1 or claim 2 a kind of method that improves the paper pulp hydrogen peroxide bleaching efficiency is characterized in that said chemi-mechanical pulp is CTMP or mill preliminary treatment APMP.
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Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105723028A (en) * | 2013-11-06 | 2016-06-29 | 赢创德固赛有限公司 | Method for delignifying and bleaching pulp |
| CN106237946A (en) * | 2016-08-08 | 2016-12-21 | 湖北金民纤维材料科技有限公司 | A kind of microcapsule adapting to Deinking Pulp carbon-free body paper coating carbonless paper and production technology thereof |
| CN106245310A (en) * | 2016-08-16 | 2016-12-21 | 朱玲 | A kind of 6 amino 1 hexanol absorbent-type hydrogen peroxide bleaching stabilizers |
| CN110878483A (en) * | 2019-11-28 | 2020-03-13 | 大连中歆一品机械有限公司 | Technical method for bleaching biomass straw fibers |
| CN111636101A (en) * | 2020-04-24 | 2020-09-08 | 赛得利(九江)纤维有限公司 | Method for removing metal ions in waste cotton fabric dissolving pulp |
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Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105723028A (en) * | 2013-11-06 | 2016-06-29 | 赢创德固赛有限公司 | Method for delignifying and bleaching pulp |
| CN106237946A (en) * | 2016-08-08 | 2016-12-21 | 湖北金民纤维材料科技有限公司 | A kind of microcapsule adapting to Deinking Pulp carbon-free body paper coating carbonless paper and production technology thereof |
| CN106245310A (en) * | 2016-08-16 | 2016-12-21 | 朱玲 | A kind of 6 amino 1 hexanol absorbent-type hydrogen peroxide bleaching stabilizers |
| CN110878483A (en) * | 2019-11-28 | 2020-03-13 | 大连中歆一品机械有限公司 | Technical method for bleaching biomass straw fibers |
| CN111636101A (en) * | 2020-04-24 | 2020-09-08 | 赛得利(九江)纤维有限公司 | Method for removing metal ions in waste cotton fabric dissolving pulp |
| CN111636101B (en) * | 2020-04-24 | 2022-01-14 | 赛得利(九江)纤维有限公司 | Method for removing metal ions in waste cotton fabric dissolving pulp |
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Application publication date: 20120229 |