CN100381636C - Bleaching method of cotton stalk chemical pulp - Google Patents
Bleaching method of cotton stalk chemical pulp Download PDFInfo
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- CN100381636C CN100381636C CNB2005100843037A CN200510084303A CN100381636C CN 100381636 C CN100381636 C CN 100381636C CN B2005100843037 A CNB2005100843037 A CN B2005100843037A CN 200510084303 A CN200510084303 A CN 200510084303A CN 100381636 C CN100381636 C CN 100381636C
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- cotton stalk
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- 238000004061 bleaching Methods 0.000 title claims abstract description 81
- 229920000742 Cotton Polymers 0.000 title claims abstract description 77
- 238000000034 method Methods 0.000 title claims abstract description 63
- 229920001131 Pulp (paper) Polymers 0.000 title claims abstract description 40
- 239000002994 raw material Substances 0.000 claims abstract description 26
- 241000193385 Geobacillus stearothermophilus Species 0.000 claims abstract description 6
- 239000003513 alkali Substances 0.000 claims description 57
- 238000009835 boiling Methods 0.000 claims description 53
- 239000002002 slurry Substances 0.000 claims description 43
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical group [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 claims description 36
- 238000010009 beating Methods 0.000 claims description 29
- 239000007788 liquid Substances 0.000 claims description 15
- 239000002585 base Substances 0.000 claims description 14
- 239000000284 extract Substances 0.000 claims description 14
- 239000007787 solid Substances 0.000 claims description 14
- 239000007844 bleaching agent Substances 0.000 claims description 13
- 238000005470 impregnation Methods 0.000 claims description 12
- 238000002803 maceration Methods 0.000 claims description 12
- ZAMOUSCENKQFHK-UHFFFAOYSA-N Chlorine atom Chemical compound [Cl] ZAMOUSCENKQFHK-UHFFFAOYSA-N 0.000 claims description 11
- 239000000460 chlorine Substances 0.000 claims description 11
- 229910052801 chlorine Inorganic materials 0.000 claims description 11
- 238000004537 pulping Methods 0.000 claims description 10
- 235000011121 sodium hydroxide Nutrition 0.000 claims description 10
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 10
- 238000004519 manufacturing process Methods 0.000 claims description 8
- 229920002472 Starch Polymers 0.000 claims description 7
- 239000002253 acid Substances 0.000 claims description 7
- 235000019698 starch Nutrition 0.000 claims description 7
- 239000008107 starch Substances 0.000 claims description 7
- 238000000605 extraction Methods 0.000 claims description 6
- 239000000126 substance Substances 0.000 claims description 6
- 238000009413 insulation Methods 0.000 claims description 5
- 238000009955 starching Methods 0.000 claims description 5
- CDBYLPFSWZWCQE-UHFFFAOYSA-L Sodium Carbonate Chemical compound [Na+].[Na+].[O-]C([O-])=O CDBYLPFSWZWCQE-UHFFFAOYSA-L 0.000 claims description 4
- 238000007598 dipping method Methods 0.000 claims description 4
- 238000007667 floating Methods 0.000 claims description 4
- 229920005610 lignin Polymers 0.000 claims description 4
- 239000000203 mixture Substances 0.000 claims description 4
- 238000012545 processing Methods 0.000 claims description 4
- 238000006424 Flood reaction Methods 0.000 claims description 3
- 230000029087 digestion Effects 0.000 claims description 3
- 230000014759 maintenance of location Effects 0.000 claims description 3
- 239000000463 material Substances 0.000 claims description 3
- 150000002972 pentoses Chemical class 0.000 claims description 3
- 238000005406 washing Methods 0.000 claims description 3
- 241000894006 Bacteria Species 0.000 claims description 2
- 238000013022 venting Methods 0.000 claims description 2
- 239000000835 fiber Substances 0.000 abstract description 20
- 241001668545 Pascopyrum Species 0.000 abstract 1
- 238000007781 pre-processing Methods 0.000 abstract 1
- 241000219146 Gossypium Species 0.000 description 60
- 238000005516 engineering process Methods 0.000 description 23
- WQYVRQLZKVEZGA-UHFFFAOYSA-N hypochlorite Chemical compound Cl[O-] WQYVRQLZKVEZGA-UHFFFAOYSA-N 0.000 description 8
- 238000005660 chlorination reaction Methods 0.000 description 7
- 239000010902 straw Substances 0.000 description 7
- 241000219000 Populus Species 0.000 description 6
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 6
- 230000000694 effects Effects 0.000 description 6
- 239000001301 oxygen Substances 0.000 description 6
- 229910052760 oxygen Inorganic materials 0.000 description 6
- ZKQDCIXGCQPQNV-UHFFFAOYSA-N Calcium hypochlorite Chemical compound [Ca+2].Cl[O-].Cl[O-] ZKQDCIXGCQPQNV-UHFFFAOYSA-N 0.000 description 5
- QAOWNCQODCNURD-UHFFFAOYSA-L Sulfate Chemical compound [O-]S([O-])(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-L 0.000 description 5
- 238000002360 preparation method Methods 0.000 description 5
- 238000004458 analytical method Methods 0.000 description 4
- 230000000052 comparative effect Effects 0.000 description 4
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- 241000209140 Triticum Species 0.000 description 3
- 235000021307 Triticum Nutrition 0.000 description 3
- 239000004753 textile Substances 0.000 description 3
- VTYYLEPIZMXCLO-UHFFFAOYSA-L Calcium carbonate Chemical compound [Ca+2].[O-]C([O-])=O VTYYLEPIZMXCLO-UHFFFAOYSA-L 0.000 description 2
- MHAJPDPJQMAIIY-UHFFFAOYSA-N Hydrogen peroxide Chemical compound OO MHAJPDPJQMAIIY-UHFFFAOYSA-N 0.000 description 2
- CBENFWSGALASAD-UHFFFAOYSA-N Ozone Chemical compound [O-][O+]=O CBENFWSGALASAD-UHFFFAOYSA-N 0.000 description 2
- KFSLWBXXFJQRDL-UHFFFAOYSA-N Peracetic acid Chemical compound CC(=O)OO KFSLWBXXFJQRDL-UHFFFAOYSA-N 0.000 description 2
- KWYUFKZDYYNOTN-UHFFFAOYSA-M Potassium hydroxide Chemical compound [OH-].[K+] KWYUFKZDYYNOTN-UHFFFAOYSA-M 0.000 description 2
- AEMOLEFTQBMNLQ-BKBMJHBISA-N alpha-D-galacturonic acid Chemical compound O[C@H]1O[C@H](C(O)=O)[C@H](O)[C@H](O)[C@H]1O AEMOLEFTQBMNLQ-BKBMJHBISA-N 0.000 description 2
- 235000014633 carbohydrates Nutrition 0.000 description 2
- 150000001720 carbohydrates Chemical class 0.000 description 2
- 238000010411 cooking Methods 0.000 description 2
- OSVXSBDYLRYLIG-UHFFFAOYSA-N dioxidochlorine(.) Chemical compound O=Cl=O OSVXSBDYLRYLIG-UHFFFAOYSA-N 0.000 description 2
- 238000002845 discoloration Methods 0.000 description 2
- 238000006073 displacement reaction Methods 0.000 description 2
- 239000000047 product Substances 0.000 description 2
- 238000004076 pulp bleaching Methods 0.000 description 2
- 238000010025 steaming Methods 0.000 description 2
- 241001494508 Arundo donax Species 0.000 description 1
- 241000282461 Canis lupus Species 0.000 description 1
- KZBUYRJDOAKODT-UHFFFAOYSA-N Chlorine Chemical compound ClCl KZBUYRJDOAKODT-UHFFFAOYSA-N 0.000 description 1
- 239000004155 Chlorine dioxide Substances 0.000 description 1
- NIPNSKYNPDTRPC-UHFFFAOYSA-N N-[2-oxo-2-(2,4,6,7-tetrahydrotriazolo[4,5-c]pyridin-5-yl)ethyl]-2-[[3-(trifluoromethoxy)phenyl]methylamino]pyrimidine-5-carboxamide Chemical compound O=C(CNC(=O)C=1C=NC(=NC=1)NCC1=CC(=CC=C1)OC(F)(F)F)N1CC2=C(CC1)NN=N2 NIPNSKYNPDTRPC-UHFFFAOYSA-N 0.000 description 1
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- AQUXGCLDPVSXHA-UHFFFAOYSA-N S(=O)(=O)(O)S(=O)(=O)O.S(=O)(O)O Chemical compound S(=O)(=O)(O)S(=O)(=O)O.S(=O)(O)O AQUXGCLDPVSXHA-UHFFFAOYSA-N 0.000 description 1
- 244000007853 Sarothamnus scoparius Species 0.000 description 1
- 229910000019 calcium carbonate Inorganic materials 0.000 description 1
- 239000000920 calcium hydroxide Substances 0.000 description 1
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- 125000002091 cationic group Chemical group 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
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Abstract
The present invention provides a bleaching method of cotton stalk chemical pulp. The bleaching pulp is obtained by using cotton stalks as a fiber raw material in an alkaline process. Before multistage bleaching is carried out, bacillus stearothermophilus is added to the pulp for preprocessing before the bleaching, and the adding quantity is from 5 to 50 g/m<3>, namely that 5 to 50g of bacillus stearothermophilus is added to the pulp per cubic meter; the strain number is AS1.999. The whiteness of final pulp after being bleached can reach more than 78%, and the final pulp has good pulp performance when being matched with wood pulp; the final pulp can also be singly used. The cotton stalk chemical pulp made by the method of the present invention has good bleaching properties, and cotton stalk chemical pulp can reach the index of wheatgrass bleached pulp, and can completely satisfy the requirement for making bleached chemical pulp. The bleaching method provides a valuable method for the effective utilization of cotton stalk resources.
Description
Technical field:
The present invention relates to a kind of method for bleaching of cotton stalk chemical pulp, belong to the pulping technology for paper-making field.
Background technology:
The whiteness of paper pulp is the main quality index of paper pulp.The method for bleaching of paper pulp is that the oxygen of handicraft production era floats the earliest.Up to Sweden chemist K.W in 1774, Sheele found just the chlorination bleaching technology to be used for textile and paper after chlorine and the strong discoloration thereof.Bleaching results when just having brought into use the chlorine bleaching technology is also bad, and the finished product damage is serious.
French chemist Berthollet finds that the bleaching liquor effect that potassium hydroxide (KOH) absorbs behind the chlorine is better, to the damage of finished product seldom.Begin postassium hypochlorite (KCIO) in 1789 and be used to bleach textiles.After several years, another one french chemist Labarraque finds to replace potassium hydroxide (KOH) can make similar bleaching liquor with NaOH (NaOH).
Scotland chemist C.Tennant in 1798 finds that absorbing chlorine with milk of lime can be made into after calcium hypochlorite is used for bleaching, and paper industry has just obtained bleaching agent with low cost.But the transportation of liquid bleaching liquor is very inconvenient, and 1799, C.Tennant made the bleaching powder of solid state, and one jumps and becomes the unique bleaching agent of textile and paper industry.Calcium hypochlorite is beginning in 1800 as the bleaching agent of paper pulp.U.S. Gilpin paper mill in 1804 is the paper mill of North America first hand with the bleaching powder bleaching, and bleaching is carried out under the dense 3-4% of slurry in beater.German Bellmer brother had reformed bleaching equipment in 1895, had made the Bel wheat Bellmer of using till today, and the bleached pulp of this equipment is dense brings up to 7%, therefore, has improved bleaching efficiency greatly.
1903, Rolm-Haas company proposed to use low sulphite (dithionate) and makes bleaching agent.Germany had proposed with hydrogen peroxide and chlorine multistage bleaching ground wood pulp in 1905.Began in 1919 to prepare the calcium hypochlorite bleaching liquor in the paper mill with liquid chlorine.Nineteen twenty has begun the hypochlorite multistage bleaching.Nineteen twenty-one U.S. Newton Falls papermaking company begins to adopt first high dense (15-25%) Bellmer (the horizontal Bellmer of Wolf).The dense continuous bleaching device of vertical height has appearred in nineteen twenty-five.Nineteen thirty begins to carry out the phase I of continuous chlorination as bleaching with elemental chlorine, obtained for the first time whiteness thus and be 70% float sulfate wood pulp entirely.Nineteen thirty-seven, Sweden used chlorine dioxide ClO for the first time in alkaline medium
2Bleaching agent as prebleaching paper pulp.Sweden in 1938 for the first time in acid medium with using ClO
2Bleaching agent as prebleaching paper pulp.1940, peroxide was used for bleached mechanical pulp and has reached perfect stage.Nineteen forty-six ClO
2Formally be used for the multistage bleaching production system, therefore to nineteen fifty, the whiteness of sulfate wood pulp can be floated to more than 90%.Nineteen fifty-two; Soviet Union wood chemistry expert NiKitin and AKim find that elemental oxygen has discoloration; but because of carbohydrate degradation seriously fails to be used for to produce; people such as French scientist Robert in 1964 find that magnesium salts has the effect of protection carbohydrate when oxygen floats; therefore, nineteen sixty-eight the pilot plant that continuous oxygen floats just occurred in the U.S., France and Sweden.Enstra paper mill, South Africa in 1970 has been built up in the world, and the oxygen of 220 tons of paper pulp of first daily output floats the workshop.Muskegon pulp mills of U.S. Scott papermaking company in 1972 build up the ozone bleaching pilot plant of 12 tons of paper pulp of daily output.1975, Scott company applied for the patent of chlorine-free bleaching, and had built up the CEDED displacement bleaching workshop of 500 tons of first daily outputs in the world in 1975.
From the history of association with pulp bleaching technical development, at first be to have developed chlorine bleach, comprise chlorination (technology code name C), hypochlorite bleaching (technology code name H) and ClO 2 bleaching (technology code name D) technology; Then develop oxygen bleach now, comprising oxygen-alkali bleaching (technology code name O), hydrogen peroxide bleaching (technology code name P), ozone bleaching (technology code name Z) and peracetic acid bleaching (technology code name Pa) technology etc.
Sulfate pulping adaptability is big, can utilize various assortments, and technical maturity can be produced high-intensity paper pulp.Therefore, it is the topmost pulping process that adopt countries in the world always.But the pulp brightness that sulfate process is produced is lower, and bleaching process is had relatively high expectations.In order to improve the whiteness of sulfate pulp, adopt the multistage bleaching technology usually; Wherein, the most commonly used is chlorination (technology code name C), alkali treatment (technology code name E), hypochlorite bleaching (technology code name H) tri-stage bleaching technology, i.e. CEH tri-stage bleaching technology.In paper pulp multistage bleaching process, chlorination and alkali treatment (also claiming the alkali extracting) are the stages that removes in a large number as residual lignin in the paper pulp, and how many whiteness of paper pulp do not obtain and improve, and therefore, chlorination and alkali treatment can not be used as bleaching process separately.But, chlorination and alkali treatment suitably whether, with the bleaching stage that directly has influence on thereafter.
In typical paper pulp multistage bleaching technology---in the CEH tri-stage bleaching technology, the main effect of alkali pretreatment is, removes with chlorlignin a part of indissoluble and the coloured dissolving that alkaline medium exists in the paper pulp after with chloridized.In this course of reaction, make chlorlignin dissolve equally in the alkali treatment stage.
Because developing rapidly of paper industry, caused the paper industry raw material unprecedentedly nervous, therefore, develop new paper-making pulping raw material and seem particularly important, Xinjiang of China, Gansu, Shanxi, Shandong, Henan, Shaanxi all have very abundant cotton stalk resource to can be used for papermaking.But for cotton stalk paper pulp, its pulp brightness is often undesirable, so, in order effectively to utilize cotton stalk resource, be necessary to study new cotton stalk dioxde pulp bleaching process.
Summary of the invention:
The object of the present invention is to provide a kind of method for bleaching of cotton stalk chemical pulp.
The paper pulp of bleaching of the present invention is that fibrous raw material obtains by soda pulping process with the cotton stalk.
Comprise before the bleaching of above-mentioned soda pulping process: with cotton stalk get the raw materials ready processing, impregnation process, by once boiling or secondary boiling, slightly starched, bleached then through pulp washing.
Simultaneously, the application of method for bleaching of the present invention is not limited to said process.
The described processing of getting the raw materials ready is that cotton stalk should be removed root before use, and carries out conquassation or break process.
Above-mentioned getting the raw materials ready handled after conquassation or break process, preferably further skin separated with bar, and skin and bar are carried out slurrying production respectively.
Because the difference of constituent structure, the alkali charge that uses cotton stalk bark is less than the alkali charge that uses the peeling cotton stalk separately, thereby separating treatment can be avoided because of the two difference on composition, and the one-tenth pulp yield that causes is low; Do not remove the peel cotton stalk when boiling, bigger than cotton stalk bark alkali charge, so, being regardless of defection and causing the serious or peeling cotton stalk steaming of cotton stalk bark degraded itself to separate deficiency, the one-tenth pulp yield that these all can cause is low.
Described impregnation process is that the cotton stalk after will get the raw materials ready handling floods with maceration extract, makes liquor ratio reach 1: (4-5.5), under normal pressure in insulation more than 85 degrees centigrade and mix more than 10 minutes, wherein in the condition insulation of 85-95 degree with mix 10-40 minute for well.
The content of alkali is the 25-35 grams per liter in the described maceration extract, and the weight ratio of over dry material quantity and the total liquid measure of maceration extract is 1: 2.5-3.6; The used black liquid consistency of impregnation process is 11-14 ° of Be ' (20 ℃ time), is preferably 12-14 ° of Be ' (20 ℃ time), and solid concentration 14-20% is preferably 16-20%.Said maceration extract is to contain the dense black liquor of certain alkali, is the mixed liquor of alkali and black liquor, and the Controllable Temperature of black liquor is between 80-95 ℃, and the alkali that adds in the black liquor can be caustic soda (NaOH), and addition is controlled at the 25-36 grams per liter, is preferably the 28-32 grams per liter.Black liquor can directly adopt the waste liquid that produces in the digestion process of preparation straw pulp, (liquor ratio reaches 1: 4-5.5) repetitive cycling is used the black liquor that produces in the preparation straw pulp under the condition of big liquor ratio like this, improve the extraction concentration of black liquor, reduce the discharge capacity of black liquor, thereby reach to concentrate and administer, alleviate the purpose of environmental pollution and water saving, also guaranteed simultaneously liquid phase cooking, the realization of circulation in the pot, displacement and heat washing.
The used black liquid consistency of this stage impregnation process is 11-14 ° of Be ' (20 ℃ time), is preferably 12-14 ° of Be ' (20 ℃ time), and solid concentration 14-20% is preferably 16-20%.Wherein, pH value is 11-14, preferred 11.8-13.3, and residual alkali number is the 8-12 grams per liter, is preferably the 8-10 grams per liter, COD is 150000-180000mg/l, is preferably 160000-180000mg/l.
Above-mentioned is 60-70% through holocellulose weight percentage in the cotton haulm raw material of dipping, and total lignin weight percentage is 12-20%, and the poly-pentose weight percentage is 20-25%, and yield is 86-92%.
Said yield is by after the 100 gram fibrous raw material impregnation process, dries the ratio of weighing with 100 gram raw materials again.
In the inventive method, the boiling before the bleaching can be an once boiling.
The process of once boiling is: cotton haulm raw material is put into boiling vessel, caustic soda concentration 400g/L, join alkali concn 78.8g/L, behind the preceding running of the once boiling 20min, in boiling vessel, feed water vapour, 40min once heats up, after making the interior pressure of boiling vessel reach 0.3-0.4Mpa, little pressure of exitting to boiling vessel is 0-0.02Mpa, feeds steam once more, make the pressure in the rotary spherical digester reach 0.3-0.4Mpa, carry out secondary temperature elevation under the pressure condition of 0.3-0.4Mpa, the secondary temperature elevation time is 40 minutes, temperature retention time 75-95min under the pressure of 0.3-0.4Mpa, spurt 25min then, discharge opeing.
Behind the once boiling, the residual alkali 14.88-16.43g/L of black liquor that extracts, hardness K value is 10.5-12.7, slurry 23-26 ° of SR of beating degree when the horizontal belt wash engine, weight in wet base 2.0-2.5g, hardness 14, residual alkali 0.08g/L when starching out the horizontal belt wash engine, beating degree 25-28 ° SR when decker, weight in wet base 1.9-2.0g, hardness 12.6-13.
In the inventive method, the boiling before the bleaching also can be the secondary boiling, and it adds alkali and is operating as: caustic soda concentration 400g/L, join alkali concn 47.2-51.6g/L, and it is 17% that one-level is boiled alkali charge, row's black liquor amount 5-7m
3, secondary boils and adds alkali number 0.8-0.95m
3, secondary boils alkali charge 10%;
Secondary boiling operating process is: cotton haulm raw material is packed in the boiling vessel, running 10min before one-level is boiled, add steam and carry out once boiling, behind the heating-up time 30min, once little venting 10min, add the steam 40min that heats up for the second time again, pressure black liquor 90min carries out secondary again and boils and add alkali, carries out intensification 40-60min behind the 20min three times, secondary boils temperature retention time 100-130min, spurts 15-20min.
The residual alkali 17.8-21.21g/L of boiling, hardness K value is 12.2-15, slurry is 22-25 ° of SR of beating degree when the horizontal belt wash engine, weight in wet base 2.1-2.7g, hardness 10.5-13.3, residual alkali 0.04-0.2g/L when starching out the horizontal belt wash engine, slurry beating degree 24-25 ° SR before floating, weight in wet base 2.0-2.7g, hardness 10.1-11.7.
No matter be to adopt once boiling or secondary boiling, black digestion liquid should have following index:
COD at horizontal belt wash engine extraction black liquor behind the once boiling is 144530mg/L, and the pH value is 13, Baume degrees (15 ℃) 11.604, and solid content is 14.57%, viscosity is 5.4cps/19.2 ℃, acid non-soluble substance 51700mg/L;
The COD of the one-level row black liquor of secondary boiling is 181390-187210mg/L, the pH value is 13.05-13.44, Baume degrees (15 ℃) 14.078-14.656, and solid content is 18.55-19.19%, viscosity is 7.7-8.5cps/ (18.3-19.0 ℃), acid non-soluble substance 66000-78700mg/L;
COD at horizontal belt wash engine extraction black liquor after the secondary boiling is 154230-157140mg/L, the pH value is 13.11-13.15, Baume degrees (15 ℃) 12.052-12.078, and solid content is 15.61-16.09%, viscosity is 4.7-5.5cps/18.0 ℃, acid non-soluble substance 64700-70000mg/L;
It is 853.6mg/L that one-level is boiled middle section water COD, and SS is 530mg/L;
It is 582-853.6mg/L that secondary boils middle section water COD, and SS is 450-460mg/L.
Method for bleaching of the present invention is the CEH tri-stage bleaching, and its pipeline floats logical chlorine dose 60-80kg/ ton slurry, and pipeline floats logical alkali number 9-13kg/ ton slurry, Hardness Control was 4.1-5.0K before the H section was floated, starch the dense 4.5-5.0% that is before floating, bleaching concentration is 30g/L, the bleaching liquor addition 0.06-0.1m of every side's slurry
3, bleaching time 130-210min, bleachability is 3.0-7.0%, floats pond whiteness 74.6-78.5%, floats the residual chlorine 0.17-0.31g/L in back, final whiteness can be reached for 78.9-82.0%.
Before carrying out multistage bleaching, in paper pulp, add bacillus stearothermophilus and float preceding preliminary treatment, its addition is 5-50g/m
3, promptly adding the bacillus stearothermophilus of 5-50g in every cube of paper pulp, bacterium numbering is: AS 1.999.
The cotton stalk pulp intensity index that obtains after the bleaching:
The once boiling making beating: beating degree is 31-47 ° of SR, weight in wet base 1.6-2.6g, quantitatively 59.3-60.1g/m
2, bulk 1.871-2.248cm
3/ g, fracture length 3.768-4.986Km, folding strength 11-22 time, tearability 742-774mN.
Secondary boiled making beating: beating degree is 29-46 ° of SR, weight in wet base 1.6-2.7g, quantitatively 58.5-60.3g/m
2, bulk 1.800-2.193cm
3/ g, fracture length 3.529-5.320Km, folding strength 5-20 time, tearability 225-286mN.
The final pulp brightness in bleaching back can reach more than 78%, is used with wood pulp to have good pulp property, also can use separately.
Traditional view thinks and uses cotton stalk slurrying, and resulting slurry quality is undesirable, and pulp yield is low, and alkali charge is big, and of low quality by its finished paper that makes; Researcher of the present invention has obtained the desirable cotton stalk chemical pulp of performance indications by cotton haulm raw material being carried out preliminary treatment, conditions of cooking, conditions of bleaching being improved, and can not make traditional prejudice of starching thereby abandoned cotton stalk.
Use the cotton stalk chemical pulp of the inventive method preparation, bleachability is good, can reach the index of wheat straw bleached pulp, satisfies the preparation requirement of bleach chemical pulp fully.
The cotton stalk chemical pulp of the inventive method preparation is used to join copies finished paper, and every index does not have significant change, can be used for substituting the poplar slurry fully, has alleviated the shortage of timber resources, provides valuable method to effective utilization of cotton stalk resource.
The specific embodiment:
Embodiment 1
Cotton stalk pulp boiling cost analysis:
7 balls are produced in test altogether, 11.0644 tons of output, 29.32 tons of consumption over dry cotton stalk amounts, yield rate 37.74%.
Experimental example 1
Once boiling record data table:
Secondary boiled record data table:
The cotton stalk bark fibre average length is 2.0mm, average diameter 20um; The average length of wooden core fibre is 0.74mm, and average diameter is 16um; It is more that the cotton stalk bast contains pectic substance, can find out during the course, and the pectic substance degradation product is present in the slurry in a large number, need not add starch indicator when detecting hardness; Therefore, cotton stalk preferably stores more than half a year before using, and in order to spontaneous fermentation, saves boiling alkali.
Alkali lye is difficult for infiltration during the direct boiling of cotton stalk, and raw material carries out conquassation or break process, helps improving the penetrating power of alkali lye, makes boiling more even, also will significantly reduce thick slag or fibre bundle.Present embodiment with cotton stalk fully conquassation smash, so the alkali lye dipping effect is good;
Can find out that by present embodiment cotton stalk is got the raw materials ready pulp quality is had very big influence; The difficult steaming of cotton stalk root separated, and improving alkali charge can not pulping, removes at the big sieve place of jumping substantially, and cotton stalk bark etc. easily steam to be separated component and then degrade seriously, is lowered into pulp yield, and this can hang down from the pulping weight in wet base and embody; Therefore, for guaranteeing stock quality and yield, can suitably reduce alkali charge.
Experimental example 2
Enter float the pond before, 4 slurries that float the pond add 5g/m respectively
3, 10g/m
3, 20g/m
3, 50g/m
3Bacillus stearothermophilus AS 1.999 kept under the state of stirring 8,4,2,1 hours, bleached then, and the bleaching data are as follows:
No. 1 pond is the once boiling slurry, and all the other are secondary boiled slurry, floats the back pulp brightness to be: 78.9%, 79.7%, 82.0%, 80.2%.
Experimental example 3
Cotton rod boiling black liquor index detects table:
Black liquor:
Middle section water:
Indexs such as cotton stalk black liquor of pulp making COD, Baume degrees, solid content are all than giantreed, wheat straw index height, and middle section water COD, SS are very low, illustrate that the cotton stalk pulp black liquid extraction is effective, help black liquid extraction and reduce the clear water consumption.
Experimental example 4
The intensity index data:
The making beating of once boiling laboratory:
The making beating of secondary boiled laboratory:
The fibre analysis tables of data:
1, frequency of fibers distributes (%), cotton stalk once boiling slurry laboratory defibrination
| Length of interval | (31，2.6) | (35，2.2) | (40，2.2) | (47，1.6) |
| 0.07～0.42 | 66.30 | 65.78 | 68.68 | 68.99 |
| 0.42～0.82 | 27.85 | 27.75 | 25.35 | 24.28 |
| 0.82～1.22 | 4.85 | 4.90 | 4.53 | 4.85 |
| 1.22～1.62 | 0.75 | 1.03 | 0.93 | 0.83 |
| 1.62～2.02 | 0.30 | 0.33 | 0.20 | 0.30 |
| 2.02 more than | 0.23 | 0.23 | 0.33 | 0.20 |
2, fibre morphology analysis
3, the secondary boiled slurry of frequency of fibers distribution (%) 3# workshop cotton stalk laboratory defibrination
| Length of interval | (29.0，2.7) | (34.5，2.6) | (43.0，1.7) | (46.5，1.6) |
| 0.07～0.42 | 64.33 | 64.35 | 65.25 | 65.45 |
| 0.42～0.82 | 29.23 | 29.65 | 28.70 | 29.05 |
| 0.82～1.22 | 5.03 | 4.90 | 4.82 | 4.43 |
| 1.22～1.62 | 0.90 | 0.43 | 0.75 | 0.68 |
| 1.62～2.02 | 0.30 | 0.15 | 0.40 | 0.18 |
| 2.02 more than | 0.23 | 0.23 | 0.08 | 0.23 |
4, fibre morphology analysis
Analyze from the fibre analysis data: the cotton stem pulp of once boiling is after beating degree reaches 40 ° of SR, 0.42mm following fiber content obviously increases, 0.42-0.82mm between fiber content obviously reduce, after this pull an oar the cutting action of fiber is strengthened, the intensity index of slurry descends, in the making beating curve same result is arranged also, slurry intensity index when 40 ° of SR left and right sides of beating degree is best.In low beating degree scope, the fibre length fall of slurry is less, can find out also that from the making beating curve weight in wet base of slurry changes not obvious, this illustrates that also the cotton stalk slurry easily pulls an oar, the suction swollen performance of fiber is good, the easy wire-dividing broom purification of fiber, and the intensity index of slurry is better.
This is tested secondary boiled slurry and compares with the once boiling slurry, and tearability changes greatly, and is different with the result that pulled an oar for several times in the past, and these group data await further checking.
Comparative example 1-3 is that cotton stalk pulp is joined and copied art paper experiment, in process of the test, has carried out joining of 20%, 30%, 40% 3 proportioning of cotton stalk pulp copying test, stablize the consumption of needle slurry 31%, straw pulp 29% simultaneously, cotton stalk pulp and poplar is starched compare; Starch, CaCO in the slurry
3And other various auxiliary dosages remain unchanged.
Comparative example 1
Production technology is according to 128g/m
2Art paper carries out, and wet end furnish is:
| Project | Unit | 1 | 2 | 3 | 4 |
| Needle slurry consumption | ％ | 31 | 31 | 31 | 31 |
| Poplar slurry consumption | ％ | 40 | 20 | 10 | 0 |
| The cotton stalk pulp consumption | ％ | 0 | 20 | 30 | 40 |
| The straw pulp consumption | ％ | 29 | 29 | 29 | 29 |
| Starch consumption in the slurry | Kg/ ton slurry | 18.8 | 18.8 | 18.8 | 18.8 |
| The P47 consumption | ppm | 500 | 500 | 500 | 500 |
| CaCO 3Consumption | Kg/ ton slurry | 140 | 140 | 140 | 140 |
Beating process requires:
Testing result:
Can know according to above result, because the cotton stalk pulp fiber is soft, making beating easily.
Learn that from the making beating curve cotton stalk pulp easily divides silk, brooming, bond strength is good between the fiber, beating degree about 40 ° of SR in, cotton stalk pulp has best intensity index; So when the control refining pulp quality, will select the making beating of moderate strength, guarantee that fiber well divides silk, brooming, and too do not cut off; Microscopic examination after the production process making beating, the cotton stalk pulp fiber produces a desired effect.
Comparative example 2
Paper machine technological parameter:
| Index | Unit | No cotton stalk pulp | 20% cotton stalk pulp | 30% cotton stalk pulp | 40% cotton stalk pulp |
| The speed of a motor vehicle | m/min | 186 | 186 | 189.9 | 190.9 |
| Couch roll vacuum | MPa | 0.08 | 0.08 | 0.075 | 0.076 |
| Suction moves roller vacuum | MPa | 0.06 | 0.06 | 0.06 | 0.06 |
| One pressure pressure | MPa | 0.45/0.46 | 0.45/0.46 | 0.46/0.45 | 0.46/0.45 |
| Two pressure pressures | MPa | 0.45/0.45 | 0.45/0.45 | 0.45/0.45 | 0.45/0.45 |
| Positive pressure pressure | MPa | 0.48/0.48 | 0.48/0.48 | 0.48/0.44 | 0.48/0.45 |
| Optical pressure pressure | MPa | 0.05/0 | 0.05/0 | 0.04/0 | 0.05/0 |
| Coating vapour pressure the last period | MPa | 0.281 | 0.333 | 0.313 | 0.336 |
| Be coated with the first two section vapour pressure | MPa | 0.074 | 0.124 | 0.101 | 0.112 |
| Be coated with back one section vapour pressure | MPa | 0.302 | 0.312 | 0.301 | 0.336 |
Become the paper achievement data:
By last table data as seen, after slurry partly replaces the poplar slurry, become the paper folding strength to improve, all the other indexs change little, and page tries seal on four look Heidelberg printing machines respond well, do not have bad effect and produce, and printed patterns is clear.
Comparative example 3
Cotton stalk is joined and is copied electro-photographic paper, and production technology is according to 60 gram/m
2Electro-photographic paper carries out.
Batching:
Cationic starch (KG/T slurry): 8
AKD (KG/T slurry): 10-12
Calcium carbonate (KG/T slurry): 150
Cotton stalk pulp with 66% replaces the poplar slurry fully, the straw pulp self-control, and other production technologies remain unchanged, and paper machine speed is controlled at 138-140m/min, the one-tenth paper index before and after the contrast.Become paper index such as following table:
After cotton stalk pulp was used for electro-photographic paper and replaces poplar slurry fully, it was little to become the paper index to change.
Claims (10)
1. the method for bleaching of a cotton stalk chemical pulp, it is characterized in that, the described paper pulp of bleaching is that fibrous raw material obtains by soda pulping process with the cotton stalk, comprise before the soda pulping process bleaching: with the cotton stalk processing of getting the raw materials ready, impregnation process, by once boiling or secondary boiling, slightly starched, bleach then through pulp washing, described method for bleaching is the CEH tri-stage bleaching, its pipeline floats logical chlorine dose 60-80kg/ ton slurry, pipeline floats logical alkali number 9-13kg/ ton slurry, Hardness Control was 4.1-5.0K before the H section was floated, starch the dense 4.5-5.0% that is before floating, bleaching concentration is 30g/L, the bleaching liquor addition 0.06-0.1m of every side's slurry
3, bleaching time 130-210min, bleachability is 3.0-7.0%, floats pond whiteness 74.6-78.5%, floats the residual chlorine 0.17-0.31g/L in back, final whiteness is 78.9-82.0%.
2. method for bleaching according to claim 1 is characterized in that, the described processing of getting the raw materials ready is that cotton stalk should be removed root before use, and carries out conquassation or break process.
3. method for bleaching according to claim 2 is characterized in that, described getting the raw materials ready handled after conquassation or break process, and skin is separated with bar, and skin and bar are carried out slurrying production respectively.
4. method for bleaching according to claim 1, it is characterized in that, described impregnation process is that the cotton stalk of will get the raw materials ready after handling floods with maceration extract, make liquor ratio reach 1: 4-5.5, under normal pressure in more than 85 degrees centigrade the insulation and mix more than 10 minutes, the content of alkali is the 25-35 grams per liter in the described maceration extract, and the weight ratio of over dry material quantity and the total liquid measure of maceration extract is 1: 2.5-3.6; The used black liquid consistency of impregnation process is 11-14 ° of Be ', and solid concentration 14-20%, described maceration extract contain the dense black liquor of certain alkali, it is the mixed liquor of alkali and black liquor, the temperature of black liquor is controlled between 80-95 ℃, and the alkali that adds in the black liquor is caustic soda, and addition is controlled at the 25-36 grams per liter; The used black liquid consistency of described impregnation process is 11-14 ° of Be ', solid concentration 14-20%; Wherein, the pH value is 11-14, and residual alkali number is the 8-12 grams per liter, and COD is 150000-180000mg/l; Described is 60-70% through holocellulose weight percentage in the cotton haulm raw material of dipping, and total lignin weight percentage is 12-20%, and the poly-pentose weight percentage is 20-25%, and yield is 86-92%.
5. method for bleaching according to claim 4 is characterized in that, described impregnation process is that the cotton stalk after will get the raw materials ready handling floods with maceration extract, makes liquor ratio reach 1: 4-5.5, under normal pressure in the condition insulation of 85-95 degree with mixed 10-40 minute; The content of alkali is the 25-35 grams per liter in the described maceration extract, and the weight ratio of over dry material quantity and the total liquid measure of maceration extract is 1: 2.5-3.6; The used black liquid consistency of impregnation process is 12-14 ° of Be ', and solid concentration is 16-20%; Described maceration extract is to contain the dense black liquor of certain alkali, is the mixed liquor of alkali and black liquor, and the temperature of black liquor is controlled between 80-95 ℃, and the alkali that adds in the black liquor is caustic soda, and addition is controlled at the 28-32 grams per liter; The used black liquid consistency of described impregnation process is 12-14 ° of Be ', and solid concentration is 16-20%; Wherein, the pH value is 11.8-13.3, and residual alkali number is the 8-10 grams per liter, and COD is 160000-180000mg/l; Described is 60-70% through holocellulose weight percentage in the cotton haulm raw material of dipping, and total lignin weight percentage is 12-20%, and the poly-pentose weight percentage is 20-25%, and yield is 86-92%.
6. method for bleaching according to claim 1, it is characterized in that, the process of described once boiling is: cotton haulm raw material is put into boiling vessel, caustic soda concentration 400g/L, join alkali concn 78.8g/L, behind the preceding running of the once boiling 20min, in boiling vessel, feed water vapour, 40min once heats up, after making the interior pressure of boiling vessel reach 0.3-0.4Mpa, little pressure of exitting to boiling vessel is 0-0.02Mpa, feeds steam once more, make the pressure in the rotary spherical digester reach 0.3-0.4Mpa, carry out secondary temperature elevation under the pressure condition of 0.3-0.4Mpa, the secondary temperature elevation time is 40 minutes, temperature retention time 75-95min under the pressure of 0.3-0.4Mpa, spurt 25min then, discharge opeing; Behind the once boiling, the residual alkali 14.88-16.43g/L of black liquor, starch degree K value is 10.5-12.7, slurry is 23-26 ° of SR of beating degree when the horizontal belt wash engine, the weight in wet base 2.0-2.5g of this moment, hardness 14, residual alkali 0.08g/L when starching out the horizontal belt wash engine, beating degree 25-28 ° SR when decker, weight in wet base 1.9-2.0g, hardness 12.6-13.
7. method for bleaching according to claim 1 is characterized in that, described secondary boiling, and it adds alkali and is operating as: caustic soda concentration 400g/L, join alkali concn 47.2-51.6g/L, it is 17% that one-level is boiled alkali charge, row's black liquor amount 5-7m
3, secondary boils and adds alkali number 0.8-0.95m
3, alkali charge 10%; Secondary boiling operating process is: cotton haulm raw material is packed in the boiling vessel, running 10min before one-level is boiled, one-level is boiled heating-up time 30min, carries out little venting 10min afterwards, the beginning secondary temperature elevation, time 40min, pressure black liquor 90min, secondary boils and adds alkali then, carry out intensification 40-60min behind the 20min three times, begin insulation afterwards, time 100-130min spurts 15-20min again; The residual alkali 17.8-21.21g/L of boiling, hardness K value is 12.2-15, slurry is 22-25 ° of SR of beating degree when the horizontal belt wash engine, weight in wet base 2.1-2.7, hardness 10.5-13.3, residual alkali 0.04-0.2g/L when starching out the horizontal belt wash engine, slurry beating degree 24-25 ° SR before floating, weight in wet base 2.0-2.7g, hardness 10.1-11.7.
8. according to claim 6 or 7 described method for bleaching, it is characterized in that described black digestion liquid should have following index:
Once boiling extracts black liquor on the horizontal belt wash engine COD is 144530mg/L, and the pH value is 13, and Baume degrees 11.604 in the time of 15 ℃, solid content are 14.57%, and viscosity is 5.4cps/19.2 ℃, acid non-soluble substance 51700mg/L;
The COD that the one-level of secondary boiling is boiled row's black liquor is 181390-187210mg/L, the pH value is 13.05-13.44, Baume degrees 14.078-14.656 in the time of 15 ℃, and solid content is 18.55-19.19%, viscosity is 7.7-8.5cps/ (18.3-19.0 ℃), acid non-soluble substance 66000-78700mg/L;
COD at horizontal belt wash engine extraction black liquor after the secondary boiling is 154230-157140mg/L, the pH value is 13.11-13.15, Baume degrees 12.052-12.078 in the time of 15 ℃, and solid content is 15.61-16.09%, viscosity is 4.7-5.5cps/18.0 ℃, acid non-soluble substance 64700-70000mg/L;
It is 853.6mg/L that one-level is boiled middle section water COD, and SS is 530mg/L;
It is 582-853.6mg/L that secondary boils middle section water COD, and SS is 450-460mg/L.
9. method for bleaching according to claim 1 is characterized in that, and is described before carrying out tri-stage bleaching, adds bacillus stearothermophilus and float preceding preliminary treatment in paper pulp, and its addition is 5-50g/m
3, promptly adding the bacillus stearothermophilus of 5-50g in every cube of paper pulp, bacterium numbering is: AS 1.999.
10. method for bleaching according to claim 1 is characterized in that, the cotton stalk pulp intensity index that obtains after the described bleaching:
The once boiling making beating: beating degree is 31-47 ° of SR, weight in wet base 1.6-2.6g, quantitatively 59.3-60.1g/m
2, bulk 1.871-2.248cm
3/ g, fracture length 3.768-4.986Km, folding strength 11-22 time, tearability 742-774mN;
Secondary boiling making beating: beating degree is 29-46 ° of SR, weight in wet base 1.6-2.7g, quantitatively 58.5-60.3g/m
2, bulk 1.800-2.193cm
3/ g, fracture length 3.529-5.320Km, folding strength 5-20 time, tearability 225-286mN;
The final pulp brightness in bleaching back reaches more than 78%.
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Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1115816A (en) * | 1995-06-20 | 1996-01-31 | 吴南松 | Cotton stalk pulping process |
| CN1293284A (en) * | 1999-10-13 | 2001-05-02 | 鱼京淑 | Technology for preparing paper pulp from corn stalk |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1115816A (en) * | 1995-06-20 | 1996-01-31 | 吴南松 | Cotton stalk pulping process |
| CN1293284A (en) * | 1999-10-13 | 2001-05-02 | 鱼京淑 | Technology for preparing paper pulp from corn stalk |
Non-Patent Citations (4)
| Title |
|---|
| 以CEH漂白稻草浆生产高白度胶印书刊纸. 李春良.黑龙江造纸，第4期. 1999 * |
| 全棉秆制文化用纸工艺的探索. 雷建民.纸和造纸，第4期. 1996 * |
| 微生物制浆漂白研究进展. 刘向华，邹冬生.中国生态农业学报，第10卷第2期. 2002 * |
| 棉杆造纸浅论. 邓竹湘.湖南造纸，第3期. 1995 * |
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