Summary of the invention
Therefore, the object of the present invention is to provide a kind of oxygen delignify treating method of grass high rigidity group unbleached chemical pulp, be that the grass chemical pulp is carried out oxygen delignification before not by bleaching, this method can either effectively remove lignin, reduce the chemicals usage of blanching step, and can also obtain intensity height, slurry that drainability is good.
In order to realize purpose of the present invention, a kind of oxygen delignify treating method of grass high rigidity group unbleached chemical pulp is provided, after boiling and before the bleaching, chemical pulp is carried out oxygen delignification, it is characterized in that, the hardness of described chemical pulp before carrying out oxygen delignification is permanganate number 16-28, be equivalent to card uncle valency 26-50, the hardness after oxygen delignification is permanganate number 10-14, is equivalent to card uncle valency 13-18; The hardness of preferred described chemical pulp before carrying out oxygen delignification is permanganate number 20-26, is equivalent to card uncle valency 31-46, and the hardness after oxygen delignification is permanganate number 11-13, is equivalent to card uncle valency 12.5-17.
The beating degree of the also preferred described chemical pulp of the present invention before carrying out oxygen delignification is 20-26 ° of SR, and the beating degree after oxygen delignification is 28-40 ° of SR; The beating degree of more preferably described chemical pulp before carrying out oxygen delignification is 22-25 ° of SR, and the beating degree after oxygen delignification is 28-36 ° of SR.
In order to realize purpose of the present invention, a kind of oxygen delignify treating method of grass high rigidity group unbleached chemical pulp is provided, after boiling and before the bleaching, chemical pulp is carried out oxygen delignification, this oxygen delignification comprises:
(1) hardness that obtains by boiling is permanganate number 16-28, is equivalent to the chemical pulp of card uncle valency 26-50;
(2) this chemical pulp is pumped to the oxygen delignification reaction tower, and feeds NaOH and oxygen; And
(3) this chemical pulp carries out delignification reaction in this oxygen delignification reaction tower, and obtaining hardness is permanganate number 10-14, is equivalent to the chemical pulp of card uncle valency 13-18.
Wherein, the chemical pulp hardness permanganate number in the preferred steps (1) is 20-26, is equivalent to card uncle valency 31-46, and the chemical pulp hardness in the step (3) is permanganate number 11-13, is equivalent to card uncle valency 12.5-17.
The beating degree of the chemical pulp in the also preferred described step of the present invention (1) is 20-26 ° of SR, and the beating degree of the chemical pulp in the step (3) is 28-40 ° of SR; The beating degree of the chemical pulp in the more preferably described step (1) is 22-25 ° of SR, and the beating degree of the chemical pulp in the step (3) is 28-36 ° of SR.
Chemical pulp of the present invention is increased to 28-36 ° of SR through the oxygen delignification beating degree by 22-25 ° of SR, the amplitude that raises is less, and lower through the beating degree of the grass chemical pulp behind the oxygen delignification, only be 28-36 ° of SR, for the drainability that improves the finished product chemical pulp lays the foundation.
The concentration of the preferred chemical pulp of the present invention before carrying out oxygen delignification is 8-18%.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 high; Slurry concentration is lower, and the corrosion of equipment is few, also the danger of not burning in oxygen.
The preferred described oxygen delignification of the present invention is the single hop oxygen delignification, use an oxygen delignification reaction tower, chemical pulp is the 95-100 degree in the temperature of this reaction tower import department, pressure is 0.9-1.2MPa, the temperature in exit is the 100-105 degree, and pressure is 0.2-0.6MPa, and the addition of NaOH is the 2-4% of oven dry stock weight in the oxygen delignification, the addition of oxygen is a 20-40kg slurry per ton, and the reaction time of chemical pulp in this reaction tower is 75-90 minute.Adopting the single hop oxygen delignification mainly is the intensity that guarantees paper pulp for further, relative multistage oxygen delignification, and single hop is less to cellulosic degradation.Generally speaking temperature is lower for the technological parameter of the preferred single hop oxygen delignification of the present invention, comparatively speaking the time longer, mainly be for the gentle more delignification reaction that carries out, avoid cellulosic degraded as far as possible.
The present invention also preferably was transported to a slurry with this chemical pulp and manages before described oxygen delignification, and the air that in this slurry pipe chemical pulp is carried out in the modifier treatment eliminating slurry makes it fluidization.The further preferred conveying worm that adopts is heated to 70-80 ℃ and be transported to this slurry and manage with chemical pulp.
The preferred magnesium salts of oven dry stock weight 0.2-1% that adds is as protective agent in the oxygen delignification process of the present invention.
The delignification rate is 86-98% in the preferred oxygen delignification process of the present invention.This delignification rate obtains with the ratio of the weight percentage of the lignin that contains in starching before 1 weight percentage that deducts the lignin that contains in the slurry behind the oxygen delignification and the oxygen delignification.
The raw material of chemical pulp of the present invention is the grass kind plant fiber, can be one or more the combination in straw, wheat straw, cotton stalk, bagasse or the reed.
The invention has the beneficial effects as follows:, just carry out oxygen delignification then, and the hardness of grass chemical pulp is reduced to permanganate number 10-14 owing to guarantee that before bleaching the hardness of grass group unbleached chemical pulp is permanganate number 16-28.Owing under high rigidity, grass group unbleached chemical pulp is carried out oxygen delignification, reduce to permanganate number 10-14 until hardness, both made that lignin is wherein effectively removed, reduced degradation of fiber again as far as possible.Such condition has guaranteed that the key reaction of grass chemical pulp in the oxygen delignification step is delignification, rather than cellulosic degraded, delignification rate 86-98% in its oxygen delignification process.The present invention also makes the process of bleaching later become simply, and can significantly reduce the consumption of chemicals in the follow-up bleaching process.As adopt hypochlorite bleaching, can reduce hypochlorite consumption 45-50%.And the grass chemical pulp intensity height, the water filtering performance that obtain after the final bleaching are good, and the fracture length of slurry can reach 4500-8000 rice, and folding number can reach 20-70 time.
The specific embodiment
Embodiment 1
With the boiling of wheat straw process ammonium sulfite, be specially pre-preg and adopt 4% sodium hydroxide solution, the ammonium sulfite solution addition is 10% of an over dry material quantity, liquor ratio 1: 4, heat temperature raising to 110 ℃ for the first time, insulation is 20 minutes under this temperature, littler steam bleeding 20-30 minute, post bake heat up 30 minutes to temperature be 168 ℃, be incubated 90 minutes.Slurry after the boiling is through washing, and transferring and obtaining hardness after dense is permanganate number 20, and in card primary valency 31, beating degree is 22 ° of SR, and concentration is 10% group unbleached chemical pulp, heats this slurry to 70 ℃ and is transported to middle underflow pipe by conveying worm then.This slurry makes it fluidization at the air that middle underflow Guan Zhongxian gets rid of in the slurry through modifier treatment, after centrifugal middle underflow pump is transported to the oxygen delignification reaction tower.This slurry mixed with the oxygen of the 20kg slurry per ton that adds and the NaOH of oven dry stock weight 4% in pipeline before entering reaction tower, and feeding steam should be starched heat temperature raising in pipeline.This slurry enters the oxygen delignification reaction tower after fully mixed in blender afterwards; protective agent is a magnesium sulfate; addition is 1% of an oven dry stock weight; inlet temperature 95 degree; pressure 0.9Mpa; stop and made this slurry can carry out sufficient delignification reaction in 75 minutes, tower top temperature is 100 degree, and pressure remains 0.5MPa.After finishing dealing with this slurry is spurted stock tank and dilution, this moment, the hardness of slurry was reduced to permanganate number 10, was equivalent to card uncle valency 13, and beating degree is 30 ° of SR.With pump the stock pump of dilution is gone into two sections vacuum pulp washing machine washings afterwards, traditional CEH tri-stage bleaching is adopted in the back, and be specially: C section chlorine dosage is 3% of an oven dry stock, and the concentration of slurry is 3.2%, and the temperature of bleaching is 55 ℃, and the time of bleaching is 45 minutes; The amount that the E section adds NaOH is an oven dry stock amount 2.5%, and the concentration of slurry is 12%, and bleaching temperature is 50 ℃, and the time is 120 minutes; The addition of H section clorox is 3% of an oven dry stock amount, and the temperature of bleaching is 30 ℃, and the time of bleaching is 120 minutes, and can obtain whiteness is 82%ISO, 6500 meters of fracture lengths, the high quality wheat straw pulp that folding strength is 45 times.
Embodiment 2
With the boiling of straw process caustic soda-anthraquinone method, the addition that is specially soda bath is 10% of an over dry material quantity, the anthraquinone addition is 0.7% of an over dry material quantity, liquor ratio 1: 4, heat temperature raising to 110 ℃ for the first time, insulation is 20 minutes under this temperature, littler steam bleeding 20-30 minute, for the second time heat temperature raising 30 minutes to temperature is 168 ℃, is incubated 90 minutes.Slurry after the boiling is through washing, transferring and obtaining hardness after dense is permanganate number 22, is equivalent to card uncle valency 35, and beating degree is 24 ° of SR, concentration is 12% group unbleached chemical pulp, heats this slurry to 70 ℃ then and is transported to the oxygen delignification reaction tower by the positive displacement middle underflow pump.This slurry mixed with the oxygen of the 40kg slurry per ton that adds and the NaOH of oven dry stock weight 2% in pipeline before entering reaction tower, and feeding steam should be starched heat temperature raising in pipeline.This slurry enters the oxygen delignification reaction tower after fully mixed in blender afterwards, inlet temperature 100 degree, and pressure 1.2Mpa stops in 90 minutes and makes this slurry can carry out sufficient delignification reaction, and tower top temperature is 105 to spend, and pressure remains 0.2MPa.After finishing dealing with this slurry is spurted stock tank and dilution, this moment, the hardness (permanganate number) of slurry was reduced to 14, was equivalent to card uncle valency 19, and beating degree is 28 ° of SR.With pump the stock pump of dilution is gone into two sections vacuum pulp washing machine washings afterwards, traditional CEH tri-stage bleaching is adopted in the back, and be specially: C section chlorine dosage is 4% of an oven dry stock, and the concentration of slurry is 3%, and the temperature of bleaching is 55 ℃, and the time of bleaching is 50 minutes; The amount that the E section adds NaOH is an oven dry stock amount 2%, and the concentration of slurry is 12%, and bleaching temperature is 52 ℃, and the time is 100 minutes; The addition of H section clorox is 3% of an oven dry stock amount, and the temperature of bleaching is 32 ℃, and the time of bleaching is 100 minutes, and can obtain whiteness is 74%ISO, 4500 meters of fracture lengths, the grain quality rice straw pulp that folding strength is 20 times.
Embodiment 3
Cotton stalk through the Arbiso process boiling, is specially adding total acid 5%, the cooking liquor of combined acid 1.0-3.0%, heat temperature raising to 115 ℃ for the first time, insulation is 20 minutes under this temperature, littler steam bleeding 20-30 minute, for the second time heat temperature raising 30 minutes to temperature is 165 ℃, is incubated 60 minutes.Slurry after the boiling is through washing, and transferring and obtaining hardness after dense is 16, and beating degree is 26 ° of SR, and concentration is 18% group unbleached chemical pulp, heats this slurry to 80 ℃ then and is transported to the slurry tower.The air that this slurry is got rid of in the slurry through modifier treatment earlier in the slurry tower makes it fluidization, after centrifugal middle underflow pump is transported to the first oxygen delignification reaction tower, advances the NaOH of the oxygen that adds 15kg slurry per ton before the tower and oven dry stock weight 2% and in pipeline, feed steam and should starch heat temperature raising.This slurry enters the first oxygen delignification reaction tower after fully mixed in blender afterwards; protective agent is a magnesium sulfate; addition is 1% of an oven dry stock weight; inlet temperature 90 degree, pressure 1.2Mpa stopped 30 minutes; tower top temperature is 95 degree; pressure remains 0.2MPa, this stock pump is gone into the second oxygen delignification tower again, advances the NaOH of the oxygen that adds 5kg slurry per ton before the tower and oven dry stock weight 1% and feed steam in pipeline and should starch heat temperature raising.This slurry enters the second oxygen delignification reaction tower after fully mixed in blender afterwards, inlet temperature 95 degree, pressure 1.0Mpa, stopped 40 minutes, tower top temperature is 100 degree, and pressure remains 0.6MPa, and this slurry is spurted stock tank and dilution, this moment, the hardness K (permanganate number) of slurry was reduced to 12, and beating degree is 31 ° of SR.With pump the stock pump of dilution is gone into two sections vacuum pulp washing machine washings afterwards, traditional CEH tri-stage bleaching is adopted in the back, and be specially: C section chlorine dosage is 5% of an oven dry stock, and the concentration of slurry is 3%, and the temperature of bleaching is 52 ℃, and the time of bleaching is 60 minutes; The amount that the E section adds NaOH is an oven dry stock amount 2%, and the concentration of slurry is 12%, and bleaching temperature is 55 ℃, and the time is 100 minutes; The addition of H section clorox is 2.5% of an oven dry stock amount, and the temperature of bleaching is 35 ℃, and the time of bleaching is 100 minutes, and can obtain whiteness is 78%ISO, fracture length 6600, the high-quality dogstail slurry that folding strength is 41 times.
Embodiment 4
Through soda cooking, being specially sodium hydroxide solution was 13% of over dry raw material, liquor ratio 1: 3 after straw, wheat straw mixed according to 1: 1, logical steam is heated to 110 ℃, is incubated 20 minutes, heats up 30 minutes, after the little steam bleeding, be warming up to 165 ℃, be incubated 60 minutes.Slurry after the boiling is through washing, and transferring and obtaining hardness after dense is permanganate number 24, is equivalent to card primary valency 39, and beating degree is 25 ° of SR, and concentration is 15% group unbleached chemical pulp, heats this slurry to 80 ℃ and is transported to middle underflow pipe by conveying worm then.This slurry makes it fluidization at the air that middle underflow Guan Zhongxian gets rid of in the slurry through modifier treatment, after centrifugal middle underflow pump is transported to the first oxygen delignification reaction tower, advances the NaOH of the oxygen that adds 20kg slurry per ton before the tower and oven dry stock weight 2% and in pipeline, feed steam and should starch heat temperature raising.This slurry enters the first oxygen delignification reaction tower after fully mixed in blender afterwards; protective agent is a magnesium sulfate; addition is 0.5% of an oven dry stock weight; inlet temperature 90 degree, pressure 0.9Mpa stopped 35 minutes; tower top temperature is 95 degree; pressure remains 0.3MPa, this stock pump is gone into the second oxygen delignification tower again, advances the NaOH of the oxygen that adds 10kg slurry per ton before the tower and oven dry stock weight 1% and feed steam in pipeline and should starch heat temperature raising.This slurry enters the second oxygen delignification reaction tower after fully mixed in blender afterwards, inlet temperature 100 degree, pressure 0.7Mpa, stopped 45 minutes, tower top temperature is 105 degree, and pressure remains 0.5MPa, this slurry is spurted stock tank and dilution, this moment, the hardness (permanganate number) of slurry was reduced to 10, was equivalent to card uncle valency 12, and beating degree is 37 ° of SR.With pump the stock pump of dilution is gone into two sections vacuum pulp washing machine washings afterwards, traditional CEH tri-stage bleaching is adopted in the back, and be specially: C section chlorine dosage is 5% of an oven dry stock, and the concentration of slurry is 3.2%, and the temperature of bleaching is 50 ℃, and the time of bleaching is 60 minutes; The amount that the E section adds NaOH is an oven dry stock amount 2.5%, and the concentration of slurry is 10%, and bleaching temperature is 55 ℃, and the time is 120 minutes; The addition of H section clorox is 2% of an oven dry stock amount, and the temperature of bleaching is 35 ℃, and the time of bleaching is 120 minutes, and can obtain whiteness is 76%ISO, fracture length 6100, the grain quality rice wheat straw mixed pulp that folding strength is 40 times.
Embodiment 5
After wheat straw and reed mixed according to 1: 2 through ammonium sulfite-anthraquinone boiling, be specially the sodium hydroxide solution hybrid infusion of using over dry raw material 4%, send into rotary spherical digester then, add the ammonium sulfite solution to over dry material quantity 11.5%, the anthraquinone addition is 0.8% of an over dry material quantity, liquor ratio 1: 3, heat temperature raising to 100 ℃ for the first time, insulation is 20 minutes under this temperature, littler steam bleeding 20-30 minute, for the second time heat temperature raising 30 minutes to temperature is 165 ℃, is incubated 60 minutes.Slurry after the boiling is through washing, and transferring and obtaining hardness after dense is permanganate number 22, is equivalent to card primary valency 35, and beating degree is 26 ° of SR, and concentration is 10% group unbleached chemical pulp, heats this slurry to 70 ℃ then and is transported to the oxygen delignification reaction tower through the positive displacement middle underflow pump.This slurry mixed with the oxygen of the 30kg slurry per ton that adds and the NaOH of oven dry stock weight 3% in pipeline before entering reaction tower, and feeding steam should be starched heat temperature raising in pipeline.This slurry enters the oxygen delignification reaction tower after fully mixed in blender afterwards; protective agent is a magnesium sulfate; addition is 0.2% of an oven dry stock weight; inlet temperature 98 degree; pressure 1.0Mpa; stop in 80 minutes and make this slurry can carry out sufficient delignification reaction, tower top temperature is 102 degree, and pressure remains 0.4MPa.After finishing dealing with this slurry is spurted stock tank and dilution, this moment, the hardness (permanganate number) of slurry was reduced to 13, was equivalent to card uncle valency 18, and beating degree is 32 ° of SR.With pump the stock pump of dilution is gone into two sections vacuum pulp washing machine washings afterwards, traditional CEH tri-stage bleaching is adopted in the back, and be specially: C section chlorine dosage is 4% of an oven dry stock, and the concentration of slurry is 3.5%, and the temperature of bleaching is 50 ℃, and the time of bleaching is 50 minutes; The amount that the E section adds NaOH is an oven dry stock amount 3%, and the concentration of slurry is 10%, and bleaching temperature is 52 ℃, and the time is 150 minutes; The addition of H section clorox is 2% of an oven dry stock amount, and the temperature of bleaching is 32 ℃, and the time of bleaching is 150 minutes, and can obtain whiteness is 80%ISO, 8000 meters of fracture lengths, the high-quality reed wheat straw mixed pulp that folding strength is 70 times.
Embodiment 6
Straw and bagasse were mixed after the persulfuric acid bisulfite cooking according to 1: 1, be specially sodium hydroxide solution and the black liquor mixed liquor hybrid infusion used over dry material quantity 4%, send into rotary spherical digester then, add the soda bath to over dry material quantity 12%, sulphidity is 10%, liquor ratio 1: 2.5, heat temperature raising to 140 ℃ for the first time, insulation is 40 minutes under this temperature, littler steam bleeding 20-30 minute, for the second time heat temperature raising 30 minutes to temperature is 173 ℃, is incubated 90 minutes.Slurry after the boiling is through washing, transferring and obtaining hardness after dense is permanganate number 28, be equivalent to card uncle valency 50, beating degree is 20 ° of SR, concentration is 25% group unbleached chemical pulp, heats this slurry to 80 ℃ by conveying worm then and is transported to slurry pipe chute and is transported to the first oxygen delignification reaction tower by single rotor formula high density stock pump.Adding the oxygen of 5kg slurry per ton and the NaOH of oven dry stock weight 2% in the reaction tower mixes; and feeding steam should be starched heat temperature raising in pipeline; this slurry enters this first oxygen delignification reaction tower after fully mixed in blender afterwards; protective agent is a magnesium sulfate, and addition is 0.2% of an oven dry stock weight, inlet temperature 90 degree; pressure 1.0Mpa; stopped 30 minutes, tower top temperature is 100 degree, and pressure remains 0.2MPa.Again this stock pump is gone into the second oxygen delignification tower, add the NaOH of the oxygen of 5kg slurry per ton and oven dry stock weight 0.5% and in pipeline, feed steam and should starch heat temperature raising.This slurry enters the second oxygen delignification reaction tower after fully mixed in blender, inlet temperature 100 degree, pressure 0.6Mpa, stopped 20 minutes, tower top temperature is 105 degree, and pressure remains 0.4MPa, this slurry is spurted stock tank and dilution, this moment, the hardness (permanganate number) of slurry was reduced to 12, was equivalent to card uncle valency 16, and beating degree is 34 ° of SR.With pump the stock pump of dilution is gone into two sections vacuum pulp washing machine washings afterwards, traditional CEH tri-stage bleaching is adopted in the back, and be specially: C section chlorine dosage is 3% of an oven dry stock, and the concentration of slurry is 3.5%, and the temperature of bleaching is 52 ℃, and the time of bleaching is 45 minutes; The amount that the E section adds NaOH is an oven dry stock amount 3%, and the concentration of slurry is 11%, and bleaching temperature is 50 ℃, and the time is 150 minutes; The addition of H section clorox is 2.5% of an oven dry stock amount, and the temperature of bleaching is 30 ℃, and the time of bleaching is 150 minutes, and can obtain whiteness is 78%ISO, fracture length 6500, the high-quality straw that folding strength is 44 times and bagasse mixed pulp.
Embodiment 7
After wheat straw, straw and reed mixed according to 1: 1: 2 through ammonium sulfite-anthraquinone boiling, be specially the ammonium sulfite solution that adds in the rotary spherical digester over dry material quantity 13%, the anthraquinone addition is 0.8% of an over dry material quantity, liquor ratio 1: 3, heat temperature raising to 100 ℃ for the first time, insulation is 20 minutes under this temperature, littler steam bleeding 20-30 minute, for the second time heat temperature raising 30 minutes to temperature is 165 ℃, is incubated 60 minutes.Slurry after the boiling is through washing, transferring and obtaining hardness after dense is permanganate number 26, be equivalent to card uncle valency 18, beating degree is 22 ° of SR, concentration is 20% group unbleached chemical pulp, heats this slurry to 70 ℃ then and is transported to the oxygen delignification reaction tower and feeds steam in pipeline through the gear type high density stock pump and should starch heat temperature raising.Add the oxygen of 15kg slurry per ton and the NaOH of oven dry stock weight 2.5% in the reaction tower; protective agent is a magnesium sulfate; addition is 0.5% of an oven dry stock weight; inlet temperature 100 degree; pressure 1.1Mpa; stop in 60 minutes and make this slurry can carry out sufficient delignification reaction, tower top temperature is 105 degree, and pressure remains 0.5MPa.After finishing dealing with this slurry is spurted stock tank and dilution, this moment, the hardness (permanganate number) of slurry was reduced to 10, was equivalent to card uncle valency 12, and beating degree is 36 ° of SR.With pump the stock pump of dilution is gone into two sections vacuum pulp washing machine washings afterwards, traditional CEH tri-stage bleaching is adopted in the back, and be specially: C section chlorine dosage is 3% of an oven dry stock, and the concentration of slurry is 3%, and the temperature of bleaching is 52 ℃, and the time of bleaching is 50 minutes; The amount that the E section adds NaOH is an oven dry stock amount 3%, and the concentration of slurry is 12%, and bleaching temperature is 50 ℃, and the time is 100 minutes; The addition of H section clorox is 2.5% of an oven dry stock amount, and the temperature of bleaching is 32 ℃, and the time of bleaching is 150 minutes, and can obtain whiteness is 78%ISO, 6300 meters of fracture lengths, the high-quality wheat straw that folding strength is 42 times, straw and reed mixed pulp.
Embodiment 8
To mix after the persulfuric acid bisulfite cooking according to 1: 1: 1, be specially in the dipping screw machine with to the sodium hydroxide solution and the black liquor mixed liquor hybrid infusion of over dry material quantity 4%, send into rotary spherical digester then, add soda bath in the rotary spherical digester to over dry material quantity 9%, sulphidity is 15%, liquor ratio 1: 3, afterwards, logical steam carries out the heat temperature raising first time, is warming up to 120 ℃, and insulation is 20 minutes under this temperature, again little steam bleeding 20-30 minute, heating for the second time begins logical steam, heat up 30 minutes to temperature be 165 ℃, be incubated 60 minutes.Slurry after the boiling is through washing, and transferring and obtaining hardness after dense is permanganate number 22, is equivalent to card primary valency 35, and beating degree is 24 ° of SR, and concentration is 23% group unbleached chemical pulp, heats this slurry to 80 ℃ then and is transported to the oxygen delignification reaction tower through the positive displacement high density stock pump.Add the oxygen of 30kg slurry per ton and the NaOH of oven dry stock weight 3% in the reaction tower, and feeding steam should be starched heat temperature raising in pipeline.Protective agent is a magnesium sulfate, and addition is 0.8% of an oven dry stock weight, inlet temperature 100 degree, and pressure 0.9Mpa stops in 55 minutes and makes this slurry can carry out sufficient delignification reaction, and tower top temperature is 108 to spend, and pressure remains 0.6MPa.After finishing dealing with this slurry is spurted stock tank and dilution, this moment, the hardness (permanganate number) of slurry was reduced to 10, was equivalent to card uncle valency 13, and beating degree is 38 ° of SR.With pump the stock pump of dilution is gone into two sections vacuum pulp washing machine washings afterwards, traditional CEH tri-stage bleaching is adopted in the back, and be specially: C section chlorine dosage is 4% of an oven dry stock, and the concentration of slurry is 3.2%, and the temperature of bleaching is 50 ℃, and the time of bleaching is 45 minutes; The amount that the E section adds NaOH is an oven dry stock amount 3%, and the concentration of slurry is 12%, and bleaching temperature is 52 ℃, and the time is 120 minutes; The addition of H section clorox is 2% of an oven dry stock amount, and the temperature of bleaching is 30 ℃, and the time of bleaching is 150 minutes, and can obtain whiteness is 81%ISO, 6800 meters of fracture lengths, the high-quality straw that folding strength is 46 times, bagasse and reed mixed pulp.
Embodiment 9
Bagasse through the ammonium sulfite boiling, is specially the ammonium sulfite solution that adds in the rotary spherical digester over dry material quantity 11%, and liquor ratio 1: 4 is filled the back rotary spherical digester and was dallied 20 minutes; Afterwards, logical steam carries out the heat temperature raising first time, is warming up to 110 ℃, and insulation is 20 minutes under this temperature, and littler steam bleeding 20-30 minute, heating for the second time began logical steam, heat up 30 minutes to temperature be 168 ℃, be incubated 90 minutes.Slurry after the boiling is through washing, and transferring and obtaining hardness after dense is permanganate number 21, is equivalent to card primary valency 33, and beating degree is 26 ° of SR, and concentration is 12% group unbleached chemical pulp, heats this slurry to 70 ℃ and is transported to middle underflow pipe by conveying worm then.This slurry makes it fluidization at the air that middle underflow Guan Zhongxian gets rid of in the slurry through modifier treatment, after centrifugal middle underflow pump is transported to the oxygen delignification reaction tower.This slurry mixed with the oxygen of the 40kg slurry per ton that adds and the NaOH of oven dry stock weight 4% in pipeline before entering reaction tower, and feeding steam should be starched heat temperature raising in pipeline.This slurry enters the oxygen delignification reaction tower after fully mixed in blender afterwards, inlet temperature 100 degree, and pressure 1.2Mpa stops in 90 minutes and makes this slurry can carry out sufficient delignification reaction, and tower top temperature is 105 to spend, and pressure remains 0.5MPa.After finishing dealing with this slurry is spurted stock tank and dilution, this moment, the hardness (permanganate number) of slurry was reduced to 11, was equivalent to card uncle valency 14, and beating degree is 36 ° of SR.With pump the stock pump of dilution is gone into two sections vacuum pulp washing machine washings afterwards, traditional CEH tri-stage bleaching is adopted in the back, and be specially: C section chlorine dosage is 5% of an oven dry stock, and the concentration of slurry is 3.5%, and the temperature of bleaching is 52 ℃, and the time of bleaching is 50 minutes; The amount that the E section adds NaOH is an oven dry stock amount 2%, and the concentration of slurry is 10%, and bleaching temperature is 55 ℃, and the time is 150 minutes; The addition of H section clorox is 2.5% of an oven dry stock amount, and the temperature of bleaching is 32 ℃, and the time of bleaching is 100 minutes, and can obtain whiteness is 77%ISO, 5500 meters of fracture lengths, the high-quality dogstail slurry that folding strength is 35 times.
Embodiment 10
With the ammonium sulfite-anthraquinone boiling of reed process, be specially through the cotton stalk behind the dry raw material preparation through the dipping screw machine, in the dipping screw machine with to the sodium hydroxide solution and the black liquor mixed liquor hybrid infusion of over dry material quantity 4%, send into rotary spherical digester then, adding adds ammonium sulfite solution to over dry material quantity 12% in the rotary spherical digester to the over dry material quantity, liquor ratio 1: 2.5, afterwards, logical steam carries out the heat temperature raising first time, is warming up to 120 ℃, and insulation is 40 minutes under this temperature, again little steam bleeding 20-30 minute, heating for the second time begins logical steam, heat up 30 minutes to temperature be 173 ℃, be incubated 90 minutes.Slurry after the boiling is through washing, and transferring and obtaining hardness after dense is permanganate number 23, is equivalent to card primary valency 38, and beating degree is 21 ° of SR, and concentration is 10% group unbleached chemical pulp, heats this slurry to 70 ℃ and is transported to middle underflow pipe by conveying worm then.This slurry makes it fluidization at the air that middle underflow Guan Zhongxian gets rid of in the slurry through modifier treatment, after centrifugal middle underflow pump is transported to the oxygen delignification reaction tower.This slurry mixed with the oxygen of the 30kg slurry per ton that adds and the NaOH of oven dry stock weight 3% in pipeline before entering reaction tower, and feeding steam should be starched heat temperature raising in pipeline.This slurry enters the oxygen delignification reaction tower after fully mixed in blender afterwards; protective agent is a magnesium sulfate; addition is 0.5% of an oven dry stock weight; inlet temperature 95 degree; pressure 0.9Mpa; stop in 90 minutes and make this slurry can carry out sufficient delignification reaction, tower top temperature is 104 degree, and pressure remains 0.5MPa.After finishing dealing with this slurry is spurted stock tank and dilution, this moment, the hardness (permanganate number) of slurry was reduced to 14, was equivalent to card uncle valency 19.5, and beating degree is 28 ° of SR.With pump the stock pump of dilution is gone into two sections vacuum pulp washing machine washings afterwards, traditional CEH tri-stage bleaching is adopted in the back, and be specially: C section chlorine dosage is 4% of an oven dry stock, and the concentration of slurry is 3%, and the temperature of bleaching is 55 ℃, and the time of bleaching is 60 minutes; The amount that the E section adds NaOH is an oven dry stock amount 2.5%, and the concentration of slurry is 10%, and bleaching temperature is 52 ℃, and the time is 100 minutes; The addition of H section clorox is 3% of an oven dry stock amount, and the temperature of bleaching is 35 ℃, and the time of bleaching is 120 minutes, and can obtain whiteness is 80%ISO, 7100 meters of fracture lengths, the high-quality dogstail slurry that folding strength is 60 times.
Above embodiment is used to explain the present invention, and unrestricted the present invention.Simple change as the method for oxygen delignification, the method for boiling, the method for bleaching etc. all should belong to protection scope of the present invention.