Summary of the invention
The object of the present invention is to provide a kind of paper pulp by the cornstalk preparation, this paper pulp has good performance parameter, can replace conventional wood pulp.
Another object of the present invention is to provide a kind of and prepare the method for quality pulp by maize straw, wherein the temperature retention time of boiling is short, pulp yield is high, is a kind of economy, environmental protection, to cellulose and the little preparation method of hemicellulose damage.
The 3rd purpose of the present invention is to provide a kind of cultural paper and paper for daily use by the maize straw pulp preparation.
To achieve these goals, the technical scheme of the present invention's employing is:
A kind of maize straw paper pulp, said corn stalk paper pulp is raw material with maize straw integral body, and the whiteness of said maize straw paper pulp is 38-60%ISO, and bulk is 1.8-2.5cm
3/ g, tensile index are 35-65N.m/g, and folding strength is 10-40 time, and fracture length is 4.0-6.5km, and air permeability is 70-200ml/min, and ash content is 5-10%, and tearability is 180-260mN, and the tearability index is 3.0-4.2mN.m
2/ g.
Said maize straw paper pulp is preferably: whiteness is 40-58%ISO, and bulk is 1.9-2.3cm
3/ g, tensile index are 45-60N.m/g, and folding strength is 15-30 time, and fracture length is 4.5-6.0km, and air permeability is 80-150ml/min, and ash content is 6-7%, and tearability is 200-240mN, and the tearability index is 3.5-4.0mN.m
2/ g.
Said maize straw paper pulp further is preferably: whiteness is 48-53%ISO, and bulk is 1.9-2.15cm
3/ g, tensile index are 47-53N.m/g, and folding strength is 20-30 time, and fracture length is 4.95-6.00km, and air permeability is 85-130ml/min, and ash content is 6.6%, and tearability is 220-240mN, and the tearability index is 3.5-3.9mN.m
2/ g.
Said maize straw paper pulp most preferably is: whiteness is 52%ISO, and bulk is 1.901cm
3/ g, tensile index are 52.13N.m/g, and folding strength is 25 times, and fracture length is 5.32km, and air permeability is 92ml/min, and tearability is 240mN, and the tearability index is 3.862mN.m
2/ g.
The preparation method of described maize straw paper pulp comprise get the raw materials ready, the step of boiling, black liquid extraction, the temperature retention time of said boiling is 0-50 minute, is preferably 0~40 minute, most preferably is 10~40 minutes.In the digestion process, digestion time is heating-up time and temperature retention time sum, and among the present invention, the heating-up time is 50~60 minutes, and total digestion time is 60~100 minutes, and preferred digestion time is less than 90 minutes greater than 60 minutes.
Said getting the raw materials ready is dry raw material preparation, or dry and wet stock preparation, during dry and wet stock preparation, through dewatering, being squeezed to mass dryness fraction more than 40%.
Said boiling is preferably caustic soda-anthraquinone method, Ammonium Sulfite Method or sodium carbonate method:
Said caustic soda-anthraquinone method is: in the maize straw raw material of handling well, add cooking liquor; By weight; Wherein alkali charge is in the 12-20% of NaOH to the over dry material quantity, preferred 13-15% and 17-20%, and the anthraquinone addition is 0.08% of an over dry material quantity; Liquor ratio is 1: 2.8-10, preferred 1: 2.8-4 and 1: 6-10; Feed steam and heat, heat temperature raising is incubated 0-40 minute to 120-140 ℃, preferred 20-30 minute.
Said Ammonium Sulfite Method is: in the maize straw raw material of handling well, add cooking liquor, by weight, wherein the ammonium sulfite consumption is over dry material quantity 14-22%; Preferred 16-20%; Ammonia volume is over dry material quantity 3-7%, preferred 4-6%, and the anthraquinone addition is 0.08% of an over dry material quantity; Liquor ratio is 1: 2.8-10, preferred 1: 2.8-4 and 1: 6-10; Feed steam and heat, heat temperature raising is incubated 10-50 minute to 160-175 ℃, preferred 10-40 minute.
Said sodium carbonate method is: in the maize straw raw material of handling well, add cooking liquor, by weight, wherein sodium carbonate amount is over dry material quantity 15-22%, preferred 17-22%, and liquor ratio is 1: 2.8-10, preferred 1: 2.8-4 and 1: 6-9; Feed steam and heat, be warming up to 140-155 ℃, be incubated 10-50 minute, preferred 10-40 minute.
The above-mentioned maize straw raw material of handling well is after boiling finishes; The hardness that soda processes and Ammonium Sulfite Method obtain slurry is permanganate number 16-28; Preferred hardness is permanganate number 18-23; It is permanganate number 30-35 that sodium carbonate method obtains slurry hardness, and preferred hardness is the slurry of permanganate number 31-35, and most preferably hardness is the slurry of permanganate number 32-35.
Boiling is carried out black liquid extraction to thick slurry after finishing, and obtaining concentration is the clean slurry of 8-12%.
Among the described preparation method, also comprise the step of oxygen delignification or bleaching.
Among the above-mentioned preparation method,, can select bleaching to handle again getting the raw materials ready, after the boiling, black liquid extraction, both can selecting oxygen delignification.
With concentration is that the clean slurry of 8-12% is steam heated to 90-100 ℃; Deliver to the oxygen delignification reaction tower, and add NaOH and oxygen, tower top pressure is 0.3-0.5Mpa; Adopt single hop oxygen delignification, two sections oxygen delignifications or three sections oxygen delignifications, the reaction time is 60-240min.
Said single hop oxygen delignification is: by weight, sodium hydroxide concentration is the 2-3% of oven dry stock amount, and flow of oxygen is the 20-35Kg/t slurry, H
20
2Consumption is the 0-25Kg/t slurry, and reaction temperature is 90-100 ℃, and the reaction time is 60-90min.
Said two sections oxygen delignifications are: by weight, one section oxygen delignification sodium hydroxide concentration is the 2-3% of oven dry stock amount, and flow of oxygen is the 20-35Kg/t slurry, and reaction temperature is 90-100 ℃, and the reaction time is 45-60min; Two sections oxygen delignification sodium hydroxide concentrations are the 2-3% of oven dry stock amount, and flow of oxygen is the 20-35Kg/t slurry, H
20
2Consumption is the 10-25Kg/t slurry, and reaction temperature is 110-130 ℃, and the reaction time is 60-90min, and every section centre is not provided with washing.
Said three sections oxygen delignifications are: by weight, one section oxygen delignification sodium hydroxide concentration is the 2-3% of oven dry stock amount, and flow of oxygen is the 20-35Kg/t slurry, and reaction temperature is 90-100 ℃, and the reaction time is 45-60min; Two sections oxygen delignification sodium hydroxide concentrations are the 2-3% of oven dry stock amount, and flow of oxygen is the 20-35Kg/t slurry, and reaction temperature is 100-110 ℃; Reaction time is 60-90min; Three sections oxygen delignification sodium hydroxide concentrations are the 2-3% of oven dry stock amount, and flow of oxygen is the 20-35Kg/t slurry, and reaction temperature is 100-110 ℃; Reaction time is 60-90min, and every section centre is not provided with washing section.
Described method for bleaching comprises H
2O
2Technology and CEH tri-stage bleaching.
Said H
2O
2Technology is: by weight, and H
2O
2Consumption be the oven dry stock amount 2-5%, alkali charge in NaOH to the 1-1.5% of oven dry stock amount, 0.1-0.2%, magnesium sulfate consumption that amount of chelant is the oven dry stock amount be the oven dry stock amount 0.2%, temperature is that 90-95 ℃, reaction time are 90-120min.
In the said CEH tri-stage bleaching, by weight, chloridization process is: slurry concentration is 5-8%, and the pH value is smaller or equal to 2, and the effective chlorine consumption is the 4-7% of oven dry stock amount, reaction temperature 35-50 ℃, and 1 hour reaction time; Alkali pretreatment is: the alkali consumption is counted 2% of oven dry stock amount with NaOH, slurry concentration 10%, and the pH value is 10, and reaction temperature is 35-50 ℃, and the reaction time is 1 hour; Hypochlorite bleaching is: the pH value is 9, and the effective chlorine consumption is the 2.5-4% of oven dry stock amount, and reaction temperature is 35-50 ℃, and the reaction time is 1.5-2 hour.
H
2O
2Maize straw paper pulp after the technology bleaching does not contain fluorescent whitening agent, organohalogen compounds, safety and environmental protection, the preferred H of the present invention
2O
2The technology bleaching.
Said maize straw paper pulp can be used for cultural paper, paper for daily use.
Below be detailed description of the present invention:
Because cellulosic content is higher than wheat straw in the corn stalk skin, help improving the intensity of paper pulp pulp yield and paper, and lignin content is low than wheat straw; Help boiling and bleaching, and cellulosic content is lower than wheat straw in the whole maize straw, so mostly the paper mill is that adopting the corn stalk skin is raw pulp papermaking; The one, in order to improve pulp yield; The 2nd, the pulp brightness for preparing after the adding corn stalk stalks of rice, wheat, etc. is low, and color is dark, is difficult for bleaching.When adopting corn stalk leather slurry the skin stalks of rice, wheat, etc. is separated, melting process is complicated, has increased production cost, also is difficult to realize large-scale industrialization production.Laboratory research finds that after a certain amount of modification straw stalks of rice, wheat, etc. of adding, the tensile index of prepared paper pulp, folding strength and tearability index all increase in the corn stalk skin; But this method also is after earlier maize straw skin-stalk being separated, the corn stalk stalks of rice, wheat, etc. to be carried out modification handle; The straw skin and the straw stalks of rice, wheat, etc. mix back slurrying according to certain proportioning then, and this method is only as a kind of laboratory research, and pulping process is complicated; Production cost is high, also is not suitable for the large-scale production in paper mill.
Maize straw paper pulp provided by the invention is to be raw material with maize straw integral body, and not disleaf of maize straw does not remove the stalks of rice, wheat, etc., need not carry out modification to the corn stalk stalks of rice, wheat, etc. and handle, and the method for getting the raw materials ready is simple, and the utilization rate of maize straw is high.Though maize straw cellulose content is relatively low; But hemicellulose level is higher, and the present invention has reduced the temperature retention time of the high temperature in the digestion process through improving and optimal preparation technology; Significantly alleviated half-and-half cellulosic degraded and damage of cooking liquor in the digestion process; Improved the pulp yield of maize straw paper pulp, reduced energy consumption, and the maize straw paper pulp various aspects of performance parameter of preparation is good; Meet the requirement of high-quality cultural paper and paper for daily use, can substitute wood pulp fully paper pulp parameters parameter.In view of the maize straw raw material has that the source is wide, cost is low, do not destroy advantage such as ecological environment, maize straw paper pulp has development prospect preferably.
In the art; Also have and think that oxygen delignification also is the part of association with pulp bleaching, for fear of ambiguity, in the present invention; The bleaching of maize straw paper pulp is carried out as giving a definition: the bleaching of the maize straw paper pulp described in the present invention is meant; If maize straw paper pulp of the present invention need bleaching, only be meant that the mode of other bleachings is bleached beyond the oxygen delignification mode.
The maize straw raw material requires homogeneity as much as possible when getting the raw materials ready, preferably adopt dry and wet stock preparation, with maize straw prescind, grating rubbing makes it to disperse, and screens to go out dust and impurity again, maize straw is made fines as far as possible.If moisture content changes greatly in the dry raw material preparation supplied materials, then must control the moisture content in the raw material, carry out dry and wet stock preparation; On the basis of dry raw material preparation, adopt the mode of pre-preg to adjust, the process of pre-preg comprises that the waterpower Straw-crumbling machine to washing and rubbing that maize straw carries out, had both helped further reducing the ash content in the maize straw; Can guarantee that also the maize straw dipping is all even fully; After dipping is accomplished,, be squeezed to mass dryness fraction more than 40% through dehydration; Help cooking liquor like this and evenly flood, liquor ratio could be relatively stable.
Maize straw is different from raw materials such as wheat straw, reed or timber; Maize straw is a skin stalks of rice, wheat, etc. structure; The content of different chemical composition there are differences in the skin and the stalks of rice, wheat, etc.; The main component of corn stalk skin is cellulose and lignin, and hemicellulose level is abundant relatively in the straw stalks of rice, wheat, etc., lignin content is lower, institutional framework is loose, and generally speaking lignin content content relatively low, hemicellulose is higher relatively for stalk.Contain a certain amount of hemicellulose in the paper pulp and benefit, not only can improve the yield of slurry, the performance of the others of paper pulp is also had optimum influence.In digestion process,, consider that hemicellulose level is higher in the corn stalk stalks of rice, wheat, etc. because the hemicellulose ratio is easier to degraded; And institutional framework is loose; Therefore, be raw pulp with the maize straw, the maximum temperature and the digestion time of the boiling method in its digestion process, cooking liquor consumption, boiling; The temperature retention time of high temperature in the digestion process particularly, all has remarkable influence to the pulp yield and the pulp quality of paper pulp at half-and-half cellulosic degraded and damage.No matter be in the corn stalk leather slurry or the prior art of maize straw slurrying; There is the problem that the cooking liquor consumption is big, boiling temperature is high, digestion time is long; Half-and-half cellulosic degraded and damage are particularly remarkable under HTHP for the overlong time of soak particularly, soup.And in the method for the invention; Consider the difference of chemical composition content in skin stalks of rice, wheat, etc. structure and the skin stalks of rice, wheat, etc. of maize straw; Studied the influence to lignin and half fiber degradation situation of the process conditions such as maximum temperature, intensification and insulation of cooking liquor consumption, liquor ratio, boiling, the process conditions of the boilings such as maximum temperature through adjustment soup consumption, liquor ratio, boiling have significantly reduced time of insulation; The time that makes maize straw be in HTHP shortens; Under the process conditions that reduce the damage hemicellulose as far as possible, carry out boiling, improved the pulp yield of maize straw paper pulp, reduced energy consumption and production cost.In addition; Because the hemicellulose in the maize straw and the hydroxyl of hydroxyl on the starch and cellulose surface have formed hydrogen bond, have increased the hydrogen bond quantity on the fiber combining face, thereby have increased interfibrous internal bond strength; Because the temperature retention time of high temperature is short in the digestion process; The destruction of the hydrogen bond that cooking liquor forms the hydroxyl of hydroxyl on hemicellulose and the starch and cellulose surface and damage for a short time, interfibrous internal bond strength is high, thereby has improved the physical strength performance of slurry.
Seeing that the content of lignin is lower than wheat straw in the maize straw, the content of hemicellulose, carbohydrate, crude fat, crude protein is higher relatively, and pigment content is higher; Maize straw pulp brightness after the boiling is low; And alkaline process-anthraquinone stronger with the ability sodium carbonate method delignification, little to the hemicellulose damage, pulp yield is high; Thick pulp color after the boiling is shallow, helps improving the whiteness of paper pulp; The pulping with ammonium sulfite method paper pulp yield is high, becomes the product cost low, and the thick pulp color after the boiling is shallow; Help improving the whiteness of paper pulp, paper pulp gas permeability and drainability are good, and nitrogen content and content of organics are higher relatively in the black liquor that obtains; The compoiste fertilizer fertilizer efficiency that this black liquor is processed is outstanding, effect of increasing production is very remarkable; The damage of double fiber of sodium carbonate method is little, and paper pulp yield is high, so the present invention preferred alkaline process of boiling method-anthraquinone, Ammonium Sulfite Method or sodium carbonate method when slurrying.
In the caustic soda-anthraquinone method of the present invention, alkali charge is that the anthraquinone addition is 0.08% of an over dry material quantity in the 12-20% of NaOH to the over dry material quantity; Liquor ratio is 1: 2.8-10, and at this moment, heat temperature raising is incubated boiling to 120-140 ℃; Temperature retention time can be reduced to 0-40 minute greatly, and the slurry hardness that obtains after the caustic soda-anthraquinone method boiling is permanganate number 16-28, and the slurry after the boiling is carried out black liquid extraction; Obtaining concentration is the clean slurry of 8-12%, and pulp yield is 48-55%; In the Ammonium Sulfite Method, the ammonium sulfite consumption is over dry material quantity 14-22%, and ammonia volume is over dry material quantity 3-7%, and the anthraquinone addition is 0.08% of an over dry material quantity, and liquor ratio is 1: 2.8-10; Feeding steam heats; Heat temperature raising is to 160-175 ℃; Temperature retention time can be reduced to 10-50 minute greatly, and the slurry hardness that obtains after the Ammonium Sulfite Method boiling is permanganate number 16-28, and the slurry after the boiling is carried out black liquid extraction; Obtaining concentration is the clean slurry of 8-12%, and pulp yield is 48-55%; In the sodium carbonate method, sodium carbonate amount is over dry material quantity 15-22%, and liquor ratio is 1: 2.8-10; Insulation after being warming up to 140-155 ℃, temperature retention time can be reduced to 10-50 minute, and this moment, stalk still kept original shape; Fiber does not separate, and is permanganate number 30-35 through discongesting disposed slurry hardness, then slurry is carried out black liquid extraction; Obtaining concentration is the clean slurry of 8-12%, pulp yield 65-70%.After soak 0-50 minute, most lignin is degraded in the raw material during boiling, and the degree of injury of hemicellulose is lighter; If continue to prolong temperature retention time, the degraded of hemicellulose and degree of injury will aggravate, and particularly the part hemicellulose with lignin chemical bond has taken place and is connected in the maize straw; Formed compound, under the situation that boiling constantly continues, along with lignin is constantly degraded and stripping; Must also to lose this part hemicellulose; Preparation method's of the present invention main improvement is greatly to have shortened the temperature retention time of high temperature in the digestion process, has obtained the paper pulp of high rigidity after boiling finishes, and the pulp yield of paper pulp is high.
All added anthraquinone in caustic soda-anthraquinone method among the present invention and the Ammonium Sulfite Method, the anthraquinone addition is 0.08% of an over dry material quantity, the reducing end group that anthraquinone both can carbohydrate oxidation using; Make it to avoid peeling reaction; Improve the yield of paper pulp, again can with lignin reaction, promote the degraded of lignin and remove; Reduce alkali consumption and imonium consumption, shorten digestion time.
Ammonium Sulfite Method is bigger to the corrosion of digesting apparatus, through shortening digestion time, has alleviated the corrosion consumption of cooking liquor to digesting apparatus greatly among the present invention.
The digesting apparatus that adopts during boiling is a kind of in ball-type boiling vessel, vertical digester, transverse tube type continuous steamer and the vertical continuous steamer:
(1) in the ball-type boiling vessel during boiling:
Described caustic soda-anthraquinone method is: in the maize straw raw material of handling well, add cooking liquor; Alkali charge is in the 12-16% of NaOH to the over dry material quantity; The anthraquinone addition is 0.08% of an over dry material quantity, and liquor ratio is 1: 2.8-4 feeds steam afterwards and heats; Heat temperature raising is incubated 0-30min to 120-140 ℃;
Described Ammonium Sulfite Method is: in the maize straw raw material of handling well, add cooking liquor; Wherein the ammonium sulfite consumption is over dry material quantity 14-20%; Ammonia volume is over dry material quantity 3-6%, and the anthraquinone addition is 0.08% of an over dry material quantity, and liquor ratio is 1: 2.8-4; Feed steam and heat, heat temperature raising is incubated 10-40 minute to 160-175 ℃.
Said sodium carbonate method is: in the maize straw raw material of handling well, add cooking liquor, wherein sodium carbonate amount is over dry material quantity 15-22%, and liquor ratio is 1: 2.8-10; Feed steam and heat, be warming up to 140-155 ℃ after insulation 10-50 minute, preferred 10-40 minute.
(2) in vertical digester during boiling:
Described caustic soda-anthraquinone method is: in the maize straw raw material of handling well, add cooking liquor; Alkali charge is in the 15-20% of NaOH to the over dry material quantity; The anthraquinone addition is 0.08% of an over dry material quantity, and liquor ratio is 1: 6-10 feeds steam afterwards and heats; Heat temperature raising is incubated 0-40min to 120-140 ℃;
Described Ammonium Sulfite Method is: in the maize straw raw material of handling well, add cooking liquor; Wherein the ammonium sulfite consumption is over dry material quantity 14-22%; Ammonia volume is over dry material quantity 4-7%, and the anthraquinone addition is 0.08% of an over dry material quantity, and liquor ratio is 1: 6-10; Feed steam and heat, heat temperature raising is incubated minute 10-50min to 160-175 ℃, preferred 10-40 minute.
Said sodium carbonate method is: in the maize straw raw material of handling well, add cooking liquor, wherein sodium carbonate amount is over dry material quantity 15-22%, and liquor ratio is 1: 6-9; Feed steam and heat, be warming up to 140-155 ℃ after insulation 10-50 minute, preferred 10-40 minute.
(3) in the transverse tube type continuous steamer during boiling:
Described caustic soda-anthraquinone method is: in the maize straw raw material of handling well, add cooking liquor; Alkali charge is in the 12-16% of NaOH to the over dry material quantity; The anthraquinone addition is 0.08% of an over dry material quantity, and liquor ratio is 1: 2.8-4 feeds steam afterwards and heats; Heat temperature raising is to 120-140 ℃, digestion time 20-40min;
Described Ammonium Sulfite Method is: in the maize straw raw material of handling well, add cooking liquor; Wherein the ammonium sulfite consumption is over dry material quantity 14-20%; Ammonia volume is over dry material quantity 3-6%, and the anthraquinone addition is 0.08% of an over dry material quantity, and liquor ratio is 1: 2.8-4; Feed steam and heat, heat temperature raising is to 160-175 ℃, digestion time 30-40min.
Said sodium carbonate method is: in the maize straw raw material of handling well, add cooking liquor, wherein sodium carbonate amount is over dry material quantity 15-22%, and liquor ratio is 1: 2.8-4; Feed steam and heat, be warming up to 140-155 ℃ after insulation 10-50 minute, preferred 10-40 minute.
(4) in vertical continuous steamer during boiling:
Described caustic soda-anthraquinone method is: in the maize straw raw material of handling well, add cooking liquor; Alkali charge is in the 15-20% of NaOH to the over dry material quantity; The anthraquinone addition is 0.08% of an over dry material quantity, and liquor ratio is 1: 6-10 feeds steam afterwards and heats; Heat temperature raising is incubated 0-40min to 120-140 ℃;
Described Ammonium Sulfite Method is: in the maize straw raw material of handling well, add cooking liquor; Wherein the ammonium sulfite consumption is over dry material quantity 14-22%; Ammonia volume is over dry material quantity 4-7%, and the anthraquinone addition is 0.08% of an over dry material quantity, and liquor ratio is 1: 6-10; Feed steam and heat, heat temperature raising is incubated 10-50 minute to 160-175 ℃, preferred 10-40 minute.
Said sodium carbonate method is: in the maize straw raw material of handling well, add cooking liquor, wherein sodium carbonate amount is over dry material quantity 15-22%, and liquor ratio is 1: 6-9; Feed steam and heat, be warming up to 140-155 ℃ after insulation 10-50 minute, preferred 10-40 minute.
Adopt the transverse tube type continuous steamer to also have following advantage: yield, the saving fibrous raw material that can improve slurry; The intensity of finished product slurry is good, and size performance is stable and all fair, and drainability is good, favourable to pulp washing, can improve exerting oneself of wash engine; The consumption of alkaline boiling soup is low; Steam consumption is low, steam does not have peak load, and promptly load is average, can alleviate the high cutting edge of a knife or a sword load of boiler.In the present invention, preferably adopt the transverse tube type continuous steamer to carry out boiling.
Thick slurry after caustic soda-anthraquinone method and the Ammonium Sulfite Method boiling, the religion of fiber dispersion ground is thin, need not discongest, and can directly get into black liquid extraction workshop section, discongests to make that fiber dispersion ground is thinner, increases the beating degree of slurry, increases the difficulty of wash engine; The thick slurry that obtains after the sodium carbonate method boiling gets into black liquid extraction workshop section after discongesting.Thick slurry after the boiling obtains the clean slurry that concentration is 8-12% through black liquid extraction with after washing; Get into the oxygen delignification reaction tower; Oxygen delignification is the most key continuously to the quality of paper pulp and technology, when thick slurry after black liquid extraction and washing, the efficient of oxygen delignification has just improved.
Oxygen delignification mainly is in order further to reduce the hardness of paper pulp; Oxygen delignification can adopt single hop oxygen delignification, two sections oxygen delignifications or three sections oxygen delignifications among the present invention; Be fit to after caustic soda-anthraquinone method and the Ammonium Sulfite Method boiling adopt single hop oxygen delignification or two sections oxygen delignifications, be fit to adopt three sections oxygen delignifications after the sodium carbonate method boiling.
The concentration of sending into the slurry of oxygen delignification reaction tower is 8-12%, slurry in carry out oxygen delignification under the dense condition, in the major advantage of dense oxygen delignification be: invest less; Since in the success of dense mixing and pumping technology, the processing of slurry is dense more much easier than height; Slurry concentration is lower, and corrosion on Equipment is few, the danger of also in oxygen, not burning.
Compared with prior art, beneficial effect of the present invention is:
The present invention is raw material with the maize straw; Through optimizing and improving boiling method, greatly shortened digestion time, the shortening of digestion time has reduced the degraded and the loss of needed hemicellulose in the paper pulp on to greatest extent; Improved the yield of paper pulp; Obtained high-hardness pulp, and prepared maize straw pulp strength parameter can compare favourably with hardwood pulp, be a kind of high-grade paper pulp; Can be made into high-grade cultural paper and paper for daily use, but maize straw has that the source is wide, cost is low, do not destroy advantage such as ecological environment.In addition, utilize whole maize straw slurrying, the maize straw utilization rate is high; The shortening of digestion time has not only reduced energy consumption and production cost to a great extent, has improved production efficiency; Simultaneously also alleviated the consumption of cooking liquor, improved the output of digesting apparatus digesting apparatus.
Maize straw paper pulp provided by the invention; Its whiteness is 38-60%ISO, and the color of cultural paper is off-white color, rice white, paddy white more, and color and luster is soft; Eyesight there is the certain protection effect; The wood-free paper of processing with this paper pulp have a better balanced more physicochemical property, as: pliability is better, opacity is high, drainability is poorer, but the cost balance is high, texture and bulk is good, original copy is Well-recovered after folding, printing adaptability and the printing.
The specific embodiment
Following embodiment further specifies the present invention, but the present invention is not limited to this.
Embodiment 1
The maize straw raw material is packed into after getting the raw materials ready in the vertical digester, adopt caustic soda-anthraquinone method.In vertical digester, add cooking liquor, alkali charge in NaOH to 20% of over dry material quantity, the anthraquinone addition is 0.08% of an over dry material quantity; Liquor ratio is 1: 6, feeds steam afterwards and heats, heat temperature raising to 140 ℃; Be incubated 0 minute, obtaining hardness is the thick slurry of permanganate number 26, and thick slurry is carried out black liquid extraction, pulp washing; Obtain concentration and be 12% clean slurry, pulp yield is 55%.
The whiteness of the maize straw paper pulp that obtains is 38%ISO, and bulk is 1.8cm
3/ g, tensile index are 47N.m/g, and folding strength is 10 times, and fracture length is 4.0km, and air permeability is 85ml/min, and ash content is 10%, and tearability is 180mN, and the tearability index is 3.1mN.m
2/ g.
Embodiment 2
The maize straw raw material is packed into after getting the raw materials ready in the vertical digester, adopt Ammonium Sulfite Method.In vertical digester, add cooking liquor, the ammonium sulfite consumption is an over dry material quantity 22%, and ammonia volume is an over dry material quantity 7%, and the anthraquinone addition is 0.08% of an over dry material quantity, and liquor ratio is 1: 6; Feed steam and heat, heat temperature raising to 175 ℃ is incubated 50 minutes, and obtaining hardness is the thick slurry of permanganate number 16.Thick slurry is carried out black liquid extraction, pulp washing, obtain concentration and be 8% clean slurry, pulp yield is 48%.
The whiteness of prepared maize straw paper pulp is 40%ISO, and bulk is 1.8cm
3/ g, tensile index are 45N.m/g, and folding strength is 15 times, and fracture length is 4.5km, and air permeability is 70ml/min, and ash content is 7%, and tearability is 200mN, and the tearability index is 3.0mN.m
2/ g.
Embodiment 3
The maize straw raw material is packed into after getting the raw materials ready in the transverse tube type continuous steamer, adopt caustic soda-anthraquinone method.In the transverse tube type continuous steamer, add cooking liquor, alkali charge in NaOH to 16% of over dry material quantity, the anthraquinone addition is 0.08% of an over dry material quantity; Liquor ratio is 1: 2.8, feeds steam afterwards and heats, heat temperature raising to 140 ℃; Be incubated 40 minutes, obtaining hardness is the thick slurry of permanganate number 17, and thick slurry is carried out black liquid extraction, pulp washing; Obtain concentration and be 12% clean slurry, pulp yield is 49%.
The whiteness of prepared maize straw paper pulp is 48%ISO, and bulk is 1.9cm
3/ g, tensile index are 35N.m/g, and folding strength is 10 times, and fracture length is 4.0km, and air permeability is 80ml/min, and ash content is 7%, and tearability is 188mN, and the tearability index is 3.2mN.m
2/ g.
Embodiment 4
The maize straw raw material is packed into after getting the raw materials ready in the ball-type boiling vessel, adopt Ammonium Sulfite Method.In the ball-type boiling vessel, add cooking liquor, the ammonium sulfite consumption is an over dry material quantity 20%, and ammonia volume is an over dry material quantity 6%, and the anthraquinone addition is 0.08% of an over dry material quantity, and liquor ratio is 1: 2.8; Feed steam and heat, heat temperature raising to 175 ℃ is incubated 10 minutes, and obtaining hardness is the thick slurry of permanganate number 23.Thick slurry is carried out black liquid extraction, pulp washing, obtain concentration and be 10% clean slurry, pulp yield is 53%.
The whiteness of prepared maize straw paper pulp is 41%ISO, and bulk is 1.85cm
3/ g, tensile index are 37N.m/g, and folding strength is 14 times, and fracture length is 4.5km, and air permeability is 85ml/min, and ash content is 7%, and tearability is 190mN, and the tearability index is 3.2mN.m
2/ g.
Embodiment 5
The maize straw raw material is packed into after getting the raw materials ready in the ball-type boiling vessel, adopt caustic soda-anthraquinone method.In the ball-type boiling vessel, add cooking liquor; Alkali charge in NaOH to 12% of over dry material quantity, the anthraquinone addition is 0.08% of an over dry material quantity, liquor ratio is 1: 2.8; Feeding steam afterwards heats; Heat temperature raising to 120 ℃ is incubated 30 minutes, and can obtain hardness is the thick slurry of permanganate number 18.Thick slurry is carried out black liquid extraction, pulp washing, obtain concentration and be 8% clean slurry, pulp yield is 53%.To clean slurry afterwards and carry out the CEH tri-stage bleaching, wherein, chloridization process is: slurry concentration is 5%, and the pH value is 2, and the effective chlorine consumption is 4% of an oven dry stock amount, 50 ℃ of reaction temperatures, 1 hour reaction time; Alkali pretreatment is: the alkali consumption is counted 2% of oven dry stock amount with NaOH, slurry concentration 10%, and the pH value is 10, and reaction temperature is 35 ℃, and the reaction time is 1 hour; Hypochlorite bleaching is: the pH value is 9, and the effective chlorine consumption is 4% of an oven dry stock amount, and reaction temperature is 35 ℃, and the reaction time is 1.5 hours.
The maize straw paper pulp that obtains, its whiteness are 60%ISO, and bulk is 2.5cm
3/ g, tensile index are 53N.m/g, and folding strength is 20 times, and fracture length is 4.95km, and air permeability is 100ml/min, and ash content is 5%, and tearability is 200mN, and the tearability index is 3.5mN.m
2/ g.
Embodiment 6
The maize straw raw material is packed into after getting the raw materials ready in the vertical digester, adopt caustic soda-anthraquinone method.In vertical digester, add cooking liquor; Alkali charge in NaOH to 15% of over dry material quantity, the anthraquinone addition is 0.08% of an over dry material quantity, liquor ratio is 1: 10; Feeding steam afterwards heats; Behind the heat temperature raising to 120 ℃, be incubated 40 minutes, obtaining hardness is the thick slurry of permanganate number 18.Thick slurry is carried out black liquid extraction, pulp washing, obtain concentration and be 12% clean slurry, pulp yield is 52%.To clean slurry and be heated to 100 ℃, and deliver to the oxygen delignification reaction tower, and carry out the single hop oxygen delignification, wherein sodium hydroxide concentration is 3% of an oven dry stock amount, and flow of oxygen is the 35Kg/t slurry, H
20
2Consumption is the 0Kg/t slurry, and reaction temperature is 100 ℃, and the reaction time is 90min, and tower top pressure is 0.3Mpa.After finishing dealing with this slurry is spurted stock tank and dilution, after washing, screen, purifying, obtain maize straw paper pulp.
The whiteness of the maize straw paper pulp of preparation is 53%ISO, and bulk is 2.15cm
3/ g, tensile index are 47N.m/g, and folding strength is 25 times, and fracture length is 6.00km, and air permeability is 130ml/min, and ash content is 6%, and tearability is 240mN, and the tearability index is 3.9mN.m
2/ g.
Embodiment 7
The maize straw raw material is packed into after getting the raw materials ready in the transverse tube type continuous steamer, adopt caustic soda-anthraquinone method.In the transverse tube type continuous steamer, add cooking liquor; Alkali charge in NaOH to 12% of over dry material quantity, the anthraquinone addition is 0.08% of an over dry material quantity, liquor ratio is 1: 4; Feeding steam afterwards heats; Heat temperature raising to 120 ℃ is incubated 20 minutes, and obtaining hardness is the thick slurry of permanganate number 23.Thick slurry is carried out black liquid extraction, pulp washing, obtain concentration and be 8% clean slurry, pulp yield is 54%.To clean slurry and be heated to 100 ℃, and deliver to the oxygen delignification reaction tower, and carry out the single hop oxygen delignification, wherein sodium hydroxide concentration is 2% of an oven dry stock amount, and flow of oxygen is the 30Kg/t slurry, H
20
2Consumption is the 15Kg/t slurry, and reaction temperature is 95 ℃, and the reaction time is 80min, and tower top pressure is 0.5Mpa.
The whiteness of the maize straw paper pulp of preparation is 52%ISO, and bulk is 1.901cm
3/ g, tensile index are 52.13N.m/g, and folding strength is 23 times, and fracture length is 5.32km, and air permeability is 100ml/min, and ash content is 6.6%, and tearability is 240mN, and the tearability index is 3.862mN.m
2/ g.
Embodiment 8
The maize straw raw material is packed into after getting the raw materials ready in the vertical continuous steamer, adopt caustic soda-anthraquinone method.In vertical continuous steamer, add cooking liquor; Alkali charge in NaOH to 20% of over dry material quantity, the anthraquinone addition is 0.08% of an over dry material quantity, liquor ratio is 1: 10; Feeding steam afterwards heats; Heat temperature raising to 140 ℃ is incubated 0 minute, and can obtain hardness is the thick slurry of permanganate number 28.Thick slurry is carried out black liquid extraction, pulp washing, obtain concentration and be 8% clean slurry, pulp yield is 55%.To clean slurry and be heated to 90 ℃, deliver to the oxygen delignification reaction tower, carry out two sections oxygen delignifications; Tower top pressure is 0.5Mpa, and wherein one section oxygen delignification sodium hydroxide concentration is 2% of an oven dry stock amount, and flow of oxygen is the 20Kg/t slurry; Reaction temperature is 90 ℃, and the reaction time is 45min; Two sections oxygen delignification sodium hydroxide concentrations are 3% of oven dry stock amount, and flow of oxygen is the 20Kg/t slurry, H
20
2Consumption is the 10Kg/t slurry, and reaction temperature is 110 ℃, and the reaction time is 90min, and two sections centres are not provided with washing.After finishing dealing with this slurry is spurted stock tank and dilution, after washing, screen, purifying, obtain maize straw paper pulp.
The whiteness of the maize straw paper pulp of preparation is 60%ISO, and bulk is 2.3cm
3/ g, tensile index are 65N.m/g, and folding strength is 40 times, and fracture length is 4.0km, and air permeability is 150ml/min, and ash content is 7%, and tearability is 220mN, and the tearability index is 3.5mN.m
2/ g.
Embodiment 9
The maize straw raw material is packed into after getting the raw materials ready in the ball-type boiling vessel, adopt Ammonium Sulfite Method.In the ball-type boiling vessel, add cooking liquor, the ammonium sulfite consumption is an over dry material quantity 14%, and ammonia volume is an over dry material quantity 3%, and the anthraquinone addition is 0.08% of an over dry material quantity, and liquor ratio is 1: 4; Feed steam and heat, heat temperature raising to 160 ℃ is incubated 40 minutes, and obtaining hardness is the thick slurry of permanganate number 18.Thick slurry is carried out black liquid extraction, pulp washing, obtain concentration and be 8% clean slurry, pulp yield is 50%.To clean slurry and be heated to 90 ℃, and deliver to the oxygen delignification reaction tower, and carry out the single hop oxygen delignification, wherein sodium hydroxide concentration is 2% of an oven dry stock amount, and flow of oxygen is the 20Kg/t slurry, H
20
2Consumption is the 25Kg/t slurry, and reaction temperature is 90 ℃, and the reaction time is 60min, and tower top pressure is 0.4Mpa.After finishing dealing with this slurry is spurted stock tank and dilution, after washing, screen, purifying, obtain maize straw paper pulp.
The whiteness of the maize straw paper pulp that obtains is 58%ISO, and bulk is 2.15cm
3/ g, tensile index are 60N.m/g, and folding strength is 30 times, and fracture length is 6.00km, and air permeability is 110ml/min, and ash content is 6.6%, and tearability is 240mN, and the tearability index is 3.9mN.m
2/ g.
Embodiment 10
The maize straw raw material is packed into after getting the raw materials ready in the vertical digester, adopt Ammonium Sulfite Method.In vertical digester, add cooking liquor, the ammonium sulfite consumption is an over dry material quantity 14%, and ammonia volume is an over dry material quantity 4%, and the anthraquinone addition is 0.08% of an over dry material quantity, and liquor ratio is 1: 10; Feed steam and heat, heat temperature raising to 160 ℃ is incubated 10 minutes, and obtaining hardness is the thick slurry of permanganate number 28.Thick slurry is carried out black liquid extraction, pulp washing, obtain concentration and be 8% clean slurry, pulp yield is 54%.To clean slurry and be heated to 100 ℃, and deliver to the oxygen delignification reaction tower, tower top pressure is 0.5Mpa; Adopt two sections oxygen delignifications: one section oxygen delignification sodium hydroxide concentration is 3% of an oven dry stock amount; Flow of oxygen is the 35Kg/t slurry, and reaction temperature is 100 ℃, and the reaction time is 60min; Two sections oxygen delignification sodium hydroxide concentrations are 2% of oven dry stock amount, and flow of oxygen is the 35Kg/t slurry, H
20
2Consumption is the 25Kg/t slurry, and reaction temperature is 130 ℃, and the reaction time is 60min, and every section centre is not provided with washing.After finishing dealing with this slurry is spurted stock tank and dilution, after washing, screen, purifying, obtain maize straw paper pulp.
The whiteness of the maize straw paper pulp of preparation is 60%ISO, and bulk is 2.15cm
3/ g, tensile index are 60N.m/g, and folding strength is 27 times, and fracture length is 6.5km, and air permeability is 130ml/min, and ash content is 7%, and tearability is 240mN, and the tearability index is 4.2mN.m
2/ g.
Embodiment 11
The maize straw raw material is packed into after getting the raw materials ready in the transverse tube type continuous steamer, adopt Ammonium Sulfite Method.In the transverse tube type continuous steamer, add cooking liquor, the ammonium sulfite consumption is an over dry material quantity 20%, and ammonia volume is an over dry material quantity 6%, and the anthraquinone addition is 0.08% of an over dry material quantity, and liquor ratio is 1: 4; Feed steam and heat, heat temperature raising to 160 ℃ is incubated 30 minutes, and obtaining hardness is the thick slurry of permanganate number 18.Thick slurry is carried out black liquid extraction, pulp washing, obtain concentration and be 12% clean slurry, pulp yield is 50%.Carry out H afterwards
2O
2Bleaching process: H
2O
2Consumption be the oven dry stock amount 2%, alkali charge in NaOH to the oven dry stock amount 1%, amount of chelant be the oven dry stock amount 0.2%, the magnesium sulfate consumption be the oven dry stock amount 0.2%, temperature is that 90 ℃, reaction time are 90min.
The whiteness of prepared maize straw paper pulp is 58%ISO, and bulk is 2.0cm
3/ g, tensile index are 45N.m/g, and folding strength is 30 times, and fracture length is 4.5km, and air permeability is 130ml/min, and ash content is 6.6%, and tearability is 200mN, and the tearability index is 4.0mN.m
2/ g.
Embodiment 12
The maize straw raw material is packed into after getting the raw materials ready in the vertical continuous steamer, adopt Ammonium Sulfite Method.In vertical continuous steamer, add cooking liquor, the ammonium sulfite consumption is an over dry material quantity 14%, and ammonia volume is an over dry material quantity 7%, and the anthraquinone addition is 0.08% of an over dry material quantity, and liquor ratio is 1: 6; Feed steam and heat, heat temperature raising to 175 ℃ is incubated 50 minutes, and obtaining hardness is the thick slurry of permanganate number 20.Thick slurry is carried out black liquid extraction, pulp washing, obtain concentration and be 8% clean slurry, pulp yield is 52%.To clean slurry and be heated to 95 ℃, and deliver to the oxygen delignification reaction tower, and carry out two sections oxygen delignifications: tower top pressure is 0.5Mpa; One section oxygen delignification sodium hydroxide concentration is 2.5% of an oven dry stock amount; Flow of oxygen is the 25Kg/t slurry, and reaction temperature is 95 ℃, and the reaction time is 50min; Two sections oxygen delignification sodium hydroxide concentrations are 2% of oven dry stock amount, and flow of oxygen is the 30Kg/t slurry, H
20
2Consumption is the 15Kg/t slurry, and reaction temperature is 120 ℃, and the reaction time is 70min, and every section centre is not provided with washing.After finishing dealing with this slurry is spurted stock tank and dilution, after washing, screen, purifying, obtain maize straw paper pulp.
The whiteness of the maize straw paper pulp of preparation is 59%ISO, and bulk is 1.901cm
3/ g, tensile index are 50N.m/g, and folding strength is 24 times, and fracture length is 5.32km, and air permeability is 92ml/min, and ash content is 6.6%, and tearability is 260mN, and the tearability index is 3.94mN.m
2/ g.
Embodiment 13
The maize straw raw material is packed into after getting the raw materials ready in the transverse tube type continuous steamer, adopt Ammonium Sulfite Method.In the transverse tube type continuous steamer, add cooking liquor, the ammonium sulfite consumption is an over dry material quantity 14%, and ammonia volume is an over dry material quantity 3%, and the anthraquinone addition is 0.08% of an over dry material quantity, and liquor ratio is 1: 2.8; Feed steam and heat, heat temperature raising to 175 ℃ is incubated 40 minutes, and obtaining hardness is the thick slurry of permanganate number 18.Thick slurry is carried out black liquid extraction, pulp washing, obtain concentration and be 12% clean slurry, pulp yield is 50%.To clean slurry afterwards and carry out the CEH tri-stage bleaching, wherein, chloridization process is: slurry concentration is 8%, and the pH value is 1.5, and the effective chlorine consumption is 7% of an oven dry stock amount, 35 ℃ of reaction temperatures, 1 hour reaction time; Alkali pretreatment is: the alkali consumption is counted 2% of oven dry stock amount with NaOH, slurry concentration 10%, and the pH value is 10, and reaction temperature is 50 ℃, and the reaction time is 1 hour; Hypochlorite bleaching is: the pH value is 9, and the effective chlorine consumption is 2.5% of an oven dry stock amount, and reaction temperature is 50 ℃, and the reaction time is 2 hours.
The whiteness of prepared maize straw paper pulp is 60%ISO, and bulk is 1.85cm
3/ g, tensile index are 53N.m/g, and folding strength is 24 times, and fracture length is 5.4km, and air permeability is 95ml/min, and ash content is 6%, and tearability is 241mN, and the tearability index is 3.86mN.m
2/ g.
Embodiment 14
The maize straw raw material is packed into after getting the raw materials ready in the ball-type boiling vessel, adopt sodium carbonate method.In the ball-type boiling vessel, add cooking liquor, wherein sodium carbonate amount is an over dry material quantity 15%, and liquor ratio is 1: 2.8; Feed steam and heat, be warming up to 155 ℃, be incubated 50 minutes, obtaining hardness is the thick slurry of permanganate number 31.Thick slurry is carried out black liquid extraction, pulp washing, obtain concentration and be 12% clean slurry, pulp yield is 68%.To clean slurry and be heated to 100 ℃, and deliver to the oxygen delignification reaction tower, and carry out three sections oxygen delignifications: tower top pressure is 0.5Mpa; One section oxygen delignification sodium hydroxide concentration is 3% of an oven dry stock amount; Flow of oxygen is the 35Kg/t slurry, and reaction temperature is 100 ℃, and the reaction time is 60min; Two sections oxygen delignification sodium hydroxide concentrations are 2% of oven dry stock amount, and flow of oxygen is the 20Kg/t slurry, and reaction temperature is 100 ℃, and the reaction time is 60min; Three sections oxygen delignification sodium hydroxide concentrations are 2% of oven dry stock amount, and flow of oxygen is the 20Kg/t slurry, and reaction temperature is 100 ℃, and the reaction time is 60min, and every section centre is not provided with washing section.
The whiteness of prepared maize straw paper pulp is 60%ISO, and bulk is 1.9cm
3/ g, tensile index are 52.13N.m/g, and folding strength is 24 times, and fracture length is 5.32km, and air permeability is 92ml/min, and ash content is 6%, and tearability is 241mN, and the tearability index is 3.87mN.m
2/ g.
Embodiment 15
The maize straw raw material is packed into after getting the raw materials ready in the vertical digester, adopt sodium carbonate method.In vertical digester, add cooking liquor, wherein sodium carbonate amount is an over dry material quantity 22%, and liquor ratio is 1: 9; Feed steam and heat, be warming up to 140 ℃, be incubated 10 minutes, obtaining hardness is the thick slurry of permanganate number 35.Thick slurry is carried out black liquid extraction, pulp washing, obtain concentration and be 8% clean slurry, pulp yield is 70%.To clean slurry and be heated to 90 ℃, and deliver to the oxygen delignification reaction tower, and carry out three sections oxygen delignifications: tower top pressure is 0.3Mpa; One section oxygen delignification sodium hydroxide concentration is 2% of an oven dry stock amount; Flow of oxygen is the 20Kg/t slurry, and reaction temperature is 90 ℃, and the reaction time is 45min; Two sections oxygen delignification sodium hydroxide concentrations are 3% of oven dry stock amount, and flow of oxygen is the 35Kg/t slurry, and reaction temperature is 110 ℃, and the reaction time is 90min; Three sections oxygen delignification sodium hydroxide concentrations are 3% of oven dry stock amount, and flow of oxygen is the 35Kg/t slurry, and reaction temperature is 110 ℃, and the reaction time is 90min, and every section centre is not provided with washing section.
The whiteness of prepared maize straw paper pulp is 58%ISO, and bulk is 1.901cm
3/ g, tensile index are 52.13N.m/g, and folding strength is 23 times, and fracture length is 5.32km, and air permeability is 92ml/min, and ash content is 6.6%, and tearability is 240mN, and the tearability index is 3.86mN.m
2/ g.
Embodiment 16
The maize straw raw material is packed into after getting the raw materials ready in the vertical digester, adopt sodium carbonate method.In vertical digester, add cooking liquor, wherein sodium carbonate amount is an over dry material quantity 15%, and liquor ratio is 1: 6; Feed steam and heat, be warming up to 155 ℃, be incubated 50 minutes, obtaining hardness is the thick slurry of permanganate number 30.Thick slurry is carried out black liquid extraction, pulp washing, obtain concentration and be 8% clean slurry, pulp yield is 65%.To clean slurry and be heated to 90 ℃, and deliver to the oxygen delignification reaction tower, and carry out three sections oxygen delignifications: tower top pressure is 0.5Mpa; One section oxygen delignification sodium hydroxide concentration is 2% of an oven dry stock amount; Flow of oxygen is the 20Kg/t slurry, and reaction temperature is 90 ℃, and the reaction time is 45min; Two sections oxygen delignification sodium hydroxide concentrations are 3% of oven dry stock amount, and flow of oxygen is the 35Kg/t slurry, and reaction temperature is 110 ℃, and the reaction time is 90min; Three sections oxygen delignification sodium hydroxide concentrations are 3% of oven dry stock amount, and flow of oxygen is the 35Kg/t slurry, and reaction temperature is 110 ℃, and the reaction time is 90min, and every section centre is not provided with washing section.After finishing dealing with this slurry is spurted stock tank and dilution, after washing, screen, purifying, obtain maize straw paper pulp.
The whiteness of prepared maize straw paper pulp is 56%ISO, and bulk is 1.901cm
3/ g, tensile index are 52.13N.m/g, and folding strength is 23 times, and fracture length is 5.32km, and air permeability is 92ml/min, and ash content is 6.6%, and tearability is 240mN, and the tearability index is 3.86mN.m
2/ g.
Embodiment 17
The maize straw raw material is packed into after getting the raw materials ready in the transverse tube type continuous steamer, adopt sodium carbonate method.In the transverse tube type continuous steamer, add cooking liquor, wherein sodium carbonate amount is an over dry material quantity 22%, and liquor ratio is 1: 4; Feed steam and heat, be warming up to 140 ℃, be incubated 50 minutes, obtaining hardness is the thick slurry of permanganate number 30.Thick slurry is carried out black liquid extraction, pulp washing, obtain concentration and be 12% clean slurry, pulp yield is 65%.To clean slurry and be heated to 100 ℃, and deliver to the oxygen delignification reaction tower, and carry out three sections oxygen delignifications: tower top pressure is 0.5Mpa; One section oxygen delignification sodium hydroxide concentration is 2% of an oven dry stock amount; Flow of oxygen is the 20Kg/t slurry, and reaction temperature is 100 ℃, and the reaction time is 45min; Two sections oxygen delignification sodium hydroxide concentrations are 2% of oven dry stock amount, and flow of oxygen is the 20Kg/t slurry, and reaction temperature is 110 ℃, and the reaction time is 90min; Three sections oxygen delignification sodium hydroxide concentrations are 2% of oven dry stock amount, and flow of oxygen is the 35Kg/t slurry, and reaction temperature is 110 ℃, and the reaction time is 60min, and every section centre is not provided with washing section.After finishing dealing with this slurry is spurted stock tank and dilution, after washing, screen, purifying, obtain maize straw paper pulp.
The whiteness of prepared maize straw paper pulp is 60%ISO, and bulk is 1.901cm
3/ g, tensile index are 53N.m/g, and folding strength is 26 times, and fracture length is 6.21km, and air permeability is 110ml/min, and ash content is 6%, and tearability is 241mN, and the tearability index is 3.862mN.m
2/ g.
Embodiment 18
The maize straw raw material is packed into after getting the raw materials ready in the transverse tube type continuous steamer, adopt sodium carbonate method.In the transverse tube type continuous steamer, add cooking liquor, wherein sodium carbonate amount is an over dry material quantity 15%, and liquor ratio is 1: 2.8; Feed steam and heat, be warming up to 155 ℃, be incubated 10 minutes, obtaining hardness is the thick slurry of permanganate number 34.Thick slurry is carried out black liquid extraction, pulp washing, obtain concentration and be 12% clean slurry, pulp yield is 70%.To clean slurry and be heated to 100 ℃, and deliver to the oxygen delignification reaction tower, and carry out three sections oxygen delignifications: tower top pressure is 0.5Mpa; One section oxygen delignification sodium hydroxide concentration is 2.5% of an oven dry stock amount; Flow of oxygen is the 30Kg/t slurry, and reaction temperature is 100 ℃, and the reaction time is 50min; Two sections oxygen delignification sodium hydroxide concentrations are 2% of oven dry stock amount, and flow of oxygen is the 20Kg/t slurry, and reaction temperature is 110 ℃, and the reaction time is 90min; Three sections oxygen delignification sodium hydroxide concentrations are 2% of oven dry stock amount, and flow of oxygen is the 35Kg/t slurry, and reaction temperature is 110 ℃, and the reaction time is 60min, and every section centre is not provided with washing section.After finishing dealing with this slurry is spurted stock tank and dilution, after washing, screen, purifying, obtain maize straw paper pulp.
The whiteness of prepared maize straw paper pulp is 60%ISO, and bulk is 1.901cm
3/ g, tensile index are 53N.m/g, and folding strength is 26 times, and fracture length is 6.21km, and air permeability is 110ml/min, and ash content is 6%, and tearability is 241mN, and the tearability index is 3.862mN.m
2/ g.
Embodiment 19
The maize straw raw material is packed into after getting the raw materials ready in the vertical continuous steamer, adopt sodium carbonate method.In vertical continuous steamer, add cooking liquor, wherein sodium carbonate amount is an over dry material quantity 22%, and liquor ratio is 1: 6; Feed steam and heat, be warming up to 155 ℃, be incubated 10 minutes, obtaining hardness is the thick slurry of permanganate number 35.Thick slurry is carried out black liquid extraction, pulp washing, obtain concentration and be 12% clean slurry, pulp yield is 70%.To clean slurry and be heated to 100 ℃, and deliver to the oxygen delignification reaction tower, and carry out three sections oxygen delignifications: tower top pressure is 0.5Mpa; One section oxygen delignification sodium hydroxide concentration is 2% of an oven dry stock amount; Flow of oxygen is the 20Kg/t slurry, and reaction temperature is 100 ℃, and the reaction time is 45min; Two sections oxygen delignification sodium hydroxide concentrations are 2% of oven dry stock amount, and flow of oxygen is the 20Kg/t slurry, and reaction temperature is 110 ℃, and the reaction time is 60min; Three sections oxygen delignification sodium hydroxide concentrations are 2% of oven dry stock amount, and flow of oxygen is the 35Kg/t slurry, and reaction temperature is 110 ℃, and the reaction time is 60min, and every section centre is not provided with washing section.After finishing dealing with this slurry is spurted stock tank and dilution, after washing, screen, purifying, obtain maize straw paper pulp.
The whiteness of prepared maize straw paper pulp is 53%ISO, and bulk is 2.01cm
3/ g, tensile index are 53N.m/g, and folding strength is 25 times, and fracture length is 6.00km, and air permeability is 90ml/min, and ash content is 6.6%, and tearability is 240mN, and the tearability index is 3.5mN.m
2/ g.
Embodiment 20
The maize straw raw material is packed into after getting the raw materials ready in the ball-type boiling vessel, adopt sodium carbonate method.In the ball-type boiling vessel, add cooking liquor, wherein sodium carbonate amount is an over dry material quantity 22%, and liquor ratio is 1: 10; Feed steam and heat, be warming up to 140 ℃, be incubated 10 minutes, obtaining hardness is the thick slurry of permanganate number 34.Thick slurry is carried out black liquid extraction, pulp washing, obtain concentration and be 12% clean slurry, pulp yield is 69%.To clean slurry and be heated to 100 ℃, and deliver to the oxygen delignification reaction tower, and carry out three sections oxygen delignifications: tower top pressure is 0.3Mpa; One section oxygen delignification sodium hydroxide concentration is 3% of an oven dry stock amount; Flow of oxygen is the 35Kg/t slurry, and reaction temperature is 100 ℃, and the reaction time is 60min; Two sections oxygen delignification sodium hydroxide concentrations are 2% of oven dry stock amount, and flow of oxygen is the 20Kg/t slurry, and reaction temperature is 100 ℃, and the reaction time is 90min; Three sections oxygen delignification sodium hydroxide concentrations are 2% of oven dry stock amount, and flow of oxygen is the 35Kg/t slurry, and reaction temperature is 100 ℃, and the reaction time is 60min, and every section centre is not provided with washing section.After finishing dealing with this slurry is spurted stock tank and dilution, after washing, screen, purifying, obtain maize straw paper pulp.
The whiteness of prepared maize straw paper pulp is 58%ISO, and bulk is 1.901cm
3/ g, tensile index are 52.13N.m/g, and folding strength is 28 times, and fracture length is 4.95km, and air permeability is 100ml/min, and ash content is 6.6%, and tearability is 241mN, and the tearability index is 3.9mN.m
2/ g.
Embodiment 21
The maize straw raw material is packed into after getting the raw materials ready in the vertical continuous steamer, adopt caustic soda-anthraquinone method.In vertical continuous steamer, add cooking liquor, alkali charge in NaOH to 15% of over dry material quantity, the anthraquinone addition is 0.08% of an over dry material quantity; Liquor ratio is 1: 9; Feed steam afterwards and heat, heat temperature raising to 140 ℃ is incubated 50 minutes; Can obtain hardness is the thick slurry of permanganate number 16, and pulp yield is 49%.Thick slurry is carried out black liquid extraction, pulp washing, obtain concentration and be 8% clean slurry.Carry out H afterwards
2O
2Bleaching process: H
2O
2Consumption be the oven dry stock amount 2%, alkali charge in NaOH to the oven dry stock amount 1%, amount of chelant be the oven dry stock amount 0.2%, the magnesium sulfate consumption be the oven dry stock amount 0.2%, temperature is that 90 ℃, reaction time are 90min.
The whiteness of resulting paper pulp is 60%ISO, and bulk is 1.8cm
3/ g, tensile index are 53N.m/g, and folding strength is 40 times, and fracture length is 4.0km, and air permeability is 150ml/min, and ash content is 6.6%, and tearability is 245mN, and the tearability index is 3.9mN.m
2/ g.
Embodiment 22
The maize straw raw material is packed into after getting the raw materials ready in the vertical continuous steamer, adopt Ammonium Sulfite Method.In vertical continuous steamer, add cooking liquor, the ammonium sulfite consumption is an over dry material quantity 22%, and ammonia volume is an over dry material quantity 4%, and the anthraquinone addition is 0.08% of an over dry material quantity, and liquor ratio is 1: 10; Feed steam and heat, heat temperature raising to 160 ℃ is incubated 10 minutes, and obtaining hardness is the thick slurry of permanganate number 23.Thick slurry is carried out black liquid extraction, pulp washing, obtain concentration and be 8% clean slurry, pulp yield is 52%.To clean slurry and be heated to 95 ℃, and deliver to the oxygen delignification reaction tower, and carry out two sections oxygen delignifications: tower top pressure is 0.3Mpa; One section oxygen delignification sodium hydroxide concentration is 3% of an oven dry stock amount; Flow of oxygen is the 20Kg/t slurry, and reaction temperature is 95 ℃, and the reaction time is 50min; Two sections oxygen delignification sodium hydroxide concentrations are 2% of oven dry stock amount, and flow of oxygen is the 30Kg/t slurry, and the H202 consumption is the 20Kg/t slurry, and reaction temperature is 120 ℃, and the reaction time is 70min, and every section centre is not provided with washing.After finishing dealing with this slurry is spurted stock tank and dilution, after washing, screen, purifying, obtain maize straw paper pulp.
The whiteness of resulting paper pulp is 60%ISO, and bulk is 1.9cm
3/ g, tensile index are 45N.m/g, and folding strength is 25 times, and fracture length is 6.22km, and air permeability is 115ml/min, and ash content is 8%, and tearability is 260mN, and the tearability index is 4.2mN.m
2/ g.
Embodiment 23
The maize straw raw material is packed into after getting the raw materials ready in the ball-type boiling vessel, adopt caustic soda-anthraquinone method.In the ball-type boiling vessel, add cooking liquor; Alkali charge in NaOH to 16% of over dry material quantity, the anthraquinone addition is 0.08% of an over dry material quantity, liquor ratio is 1: 4; Feeding steam afterwards heats; Heat temperature raising to 140 ℃ is incubated 0 minute, and can obtain hardness is the thick slurry of permanganate number 28.Thick slurry is carried out black liquid extraction, pulp washing, obtain concentration and be 8% clean slurry, pulp yield is 55%.To clean slurry and be heated to 95 ℃, and deliver to the oxygen delignification reaction tower, and carry out two sections oxygen delignifications: tower top pressure is 0.3Mpa; One section oxygen delignification sodium hydroxide concentration is 2% of an oven dry stock amount; Flow of oxygen is the 35Kg/t slurry, and reaction temperature is 95 ℃, and the reaction time is 50min; Two sections oxygen delignification sodium hydroxide concentrations are 2% of oven dry stock amount, and flow of oxygen is the 30Kg/t slurry, and the H202 consumption is the 15Kg/t slurry, and reaction temperature is 120 ℃, and the reaction time is 70min, and every section centre is not provided with washing.After finishing dealing with this slurry is spurted stock tank and dilution, after washing, screen, purifying, obtain maize straw paper pulp.
The maize straw paper pulp that obtains, its whiteness are 58%ISO, and bulk is 2.5cm
3/ g, tensile index are 53N.m/g, and folding strength is 15 times, and fracture length is 4.95km, and air permeability is 200ml/min, and ash content is 5%, and tearability is 200mN, and the tearability index is 3.5mN.m
2/ g.
Embodiment 24
Manufacture paper with pulp after the bleaching commercial wood pulp of the maize straw paper pulp of the embodiment of weight portion 75% 7 preparations and 25% mixed, obtain natural color offset plate printing paper.Described natural color offset plate printing paper quantitatively is 56g/m
2, opacity 83.7%, fracture length (in length and breadth to average) is 3.11km, and whiteness is 62.6%ISO, and laterally folding strength is 6 times, lateral extensometer shrinkage≤2.8%.