阅读说明：本技术 一种纸浆纤维的制备方法 (Preparation method of paper pulp fiber ) 是由 齐卫民 齐天洋 贾金伟 朱治强 权桂琴 尹寒松 于 2020-12-24 设计创作，主要内容包括：本发明公开了一种纸浆纤维的制备方法,包括以下步骤：在常温常压下进行(S1)切割：将秸秆切断和移除杂质得到切割后草料；(S2)破碎：将切割后草料放入破碎机进行进一步破碎；(S3)预浸：将(S2)中进一步破碎后的秸秆用螺旋预浸机加第一药水；第一药水包括NaOH 2-8％和催化剂0.1％以液比1:2组成；(S4)浸泡：将(S3)中预浸后的草料放入反应仓浸泡20小时后控干残液；(S5)脱水：将草料放入螺旋脱水机进一步脱出残液；(S6)初步研磨；(S7)二次研磨；(S8)三次研磨：将完成二次研磨的草料放入第三研磨机研磨达到所需纤维的叩解度并在第三研磨机的料仓滞留1小时得半成品；(S9)以逆流方式洗涤干净后得到成品。本发明节能环保,高收率低污染。(The invention discloses a preparation method of paper pulp fibers, which comprises the following steps: cutting (S1) at normal temperature and pressure: cutting off the straws and removing impurities to obtain cut forage; (S2) crushing: placing the cut forage into a crusher for further crushing; (S3) pre-dipping: adding a first liquid medicine into the straw which is further crushed in the step (S2) by using a spiral pre-soaking machine; the first liquid medicine comprises 2-8% of NaOH and 0.1% of catalyst in a liquid ratio of 1: 2; (S4) soaking: placing the forage presoaked in the step (S3) into a reaction bin, soaking for 20 hours, and draining residual liquid; (S5) dehydration: putting the forage into a spiral dehydrator to further remove residual liquid; (S6) preliminary grinding; (S7) secondary grinding; (S8) three times of milling: grinding the forage which is subjected to the secondary grinding in a third grinding machine to reach the required fiber beating degree, and staying in a bin of the third grinding machine for 1 hour to obtain a semi-finished product; (S9) washing in a counter-current mode to obtain a finished product. The invention is energy-saving and environment-friendly, and has high yield and low pollution.)

1. A preparation method of pulp fiber is characterized in that: the method comprises the following steps:

(S1) cutting: the method comprises the following steps of (1) bundling straws serving as raw materials by a bundling machine, cutting the straws into a straw cutter according to 3-4cm, removing mineral dust and light impurities of the straws by a six-roller dust remover to obtain cut straws;

(S2) crushing: placing the cut forage in (S1) into a crusher for further crushing;

(S3) pre-dipping: adding a first liquid medicine into the straw which is further crushed in the step (S2) by using a spiral pre-soaking machine; the first liquid medicine comprises 2-8% of NaOH and 0.1-1% of catalyst in a liquid ratio of 1: 2-6;

(S4) soaking: placing the forage presoaked in the step (S3) into a reaction bin, soaking for 20 hours, and draining residual liquid;

(S5) dehydration: putting the forage into a spiral dehydrator to further remove residual liquid;

(S6) primary grinding: conveying the material from which residual liquid is further removed to a first mill by a screw conveyer, mixing and adding a second liquid medicine for mixing and grinding, wherein the second liquid medicine comprises 2-4% of NaOH and 0.1-1% of catalyst in a liquid ratio of 1: 0.5-2;

(S7) secondary grinding: placing the forage subjected to primary grinding into a second grinding machine, mixing and grinding, feeding into a bin of the second grinding machine, and staying for 1 hour, and improving the beating degree and swelling of the slurry;

(S8) three times of milling: grinding the forage which is subjected to the secondary grinding in a third grinding machine to reach the required fiber beating degree, and staying in a bin of the third grinding machine for 1 hour to obtain a semi-finished product;

(S9) washing: putting the semi-finished product after the three-time grinding into 3 series-connected dewaterers, and washing in a counter-current mode to obtain a finished product;

the (S1) to (S9) are performed at normal temperature and pressure.

2. The method for producing pulp fibers according to claim 1, characterized in that: the straw is one or more of wheat straw, rice straw, reed or cotton stalk.

3. The method for producing pulp fibers according to claim 1, characterized in that: the straw is multiple of wheat straw, rice straw, reed or cotton stalk.

4. The method for producing pulp fibers according to claim 1, characterized in that: the raw material also comprises bamboo.

5. The method for producing pulp fibers according to claim 1, characterized in that: the liquid generated in the preparation process is recycled by adopting a liquid circulation mode; the liquid circulation comprises the following steps:

(1) water collection: collecting liquid generated by the reaction bin and the dehydrator, and pumping the liquid to a micro-filter through a water collecting tank for filtering;

(2) and (3) filtering: the lost fiber filtered by the micro-filter is sent to a dehydrator for dehydration, and the dehydrated fiber by the micro-filter automatically flows into an acidification primary sedimentation tank;

(3) primary precipitation: reducing COD, BOD, SS and precipitated sludge by an acidification primary sedimentation tank, and enabling obtained supernatant to automatically overflow to an aerobic aeration tank through an upper water outlet of the acidification primary sedimentation tank;

(4) aeration: after COD, BOD and SS are reduced again in the aerobic aeration tank under the action of aeration and aerobic bacteria, the obtained supernatant automatically overflows to the reflux tank through the upper water outlet of the aerobic aeration tank for sedimentation, and then the supernatant automatically overflows to the flocculation sedimentation tank through the upper water outlet of the reflux tank;

(5) flocculation and precipitation: adding a flocculating agent into the flocculation sedimentation tank for sedimentation, and pumping supernatant into an air floatation tank;

(6) removing dirt in the air floatation tank: after sludge is scraped off in the air flotation tank, supernatant fluid automatically overflows to a reuse water tank through an upper water outlet of the air flotation tank;

the dosage liquid used for the fiber extraction process is recycled, and the liquid does not need to be discharged.

Technical Field

The invention relates to the technical field of straw pulping, in particular to a preparation method of paper pulp fibers.

Background

Paper pulp (pulp) is a fibrous substance prepared by using plant fibers as raw materials and adopting different processing methods. Mechanical pulp, chemical pulp and chemimechanical pulp can be classified according to the processing method; the fiber raw materials can also be divided into wood pulp, straw pulp, hemp pulp, reed pulp, cane pulp, bamboo pulp, rag pulp and the like according to the used fiber raw materials. And can be divided into refined pulp, bleached pulp, unbleached pulp, high-yield pulp, semi-chemical pulp and the like according to different purities. Are commonly used in the manufacture of paper and paperboard. Refined pulp is often used as a raw material for producing cellulose derivatives such as cellulose esters and cellulose ethers, in addition to specialty paper. Also used in the fields of artificial fiber, plastic, paint, film, gunpowder and the like.

Conventional pulping refers to a process of dissociating plant fiber raw materials into natural color or bleached pulp using chemical methods, mechanical methods, or a combination thereof. The commonly adopted technical process is that the plant fiber raw material is crushed, steamed, washed, screened, bleached, purified and dried. A novel biological pulping method is developed in modern times, and is characterized in that a lignin structure is specifically and directionally decomposed by using special strains (white-rot fungi, brown-rot fungi and soft-rot fungi), then the rest cellulose is dissociated by a mechanical or chemical method, and then bleaching is carried out.

However, in the process of implementing the technical solution in the prior art, the applicant finds that the following technical problems exist in the technical solution in the prior art:

the straw and bamboo mostly need high temperature, high pressure and high alkali in the process of producing pulp fiber, and the yield is low by 35-55%. Producing one ton of unbleached pulp fiber typically requires 12% NaOH, 0.1% anthraquinone, 800kg standard coal, and a high pressure vessel. Due to the low harvest rate, a large amount of lignin and hemicellulose are dissolved out, so that the pressure of alkali recovery and water treatment is huge. The yield is 35-55% lower. The production of one ton of natural color pulp fiber usually needs 12% NaOH, 0.1% anthraquinone and 800kg standard coal, which seriously increases the production cost, but also has lower production efficiency and increases the cost of smoke dust treatment.

In addition, there is a common recognition in the prior art that it is difficult to obtain a uniformly softened slurry at a low alkali content of 12% at 0.5MPa or less. The two factors mentioned above are the main reasons for this consensus. The prior art generally softens and swells under the conditions of 0.5-0.7MPa and more than 12 percent of alkali consumption.

Disclosure of Invention

The invention aims to provide a preparation method of paper pulp fibers, which solves the technical problems of high energy consumption, low yield and environmental pollution in the prior art, and achieves the technical effects of energy conservation, environmental protection, high yield and low pollution.

In order to solve the technical problems, the technical scheme of the invention is as follows:

a preparation method of pulp fiber comprises the following steps:

(S1) cutting: the method comprises the following steps of (1) bundling straws serving as raw materials by a bundling machine, cutting the straws into a straw cutter according to 3-4cm, removing mineral dust and light impurities of the straws by a six-roller dust remover to obtain cut straws;

(S2) crushing: putting the cut forage obtained in the step (S1) into a crusher for further crushing so as to increase the specific surface area of the fiber;

(S3) pre-dipping: adding a first liquid medicine into the straw which is further crushed in the step (S2) by using a spiral pre-soaking machine; the first liquid medicine comprises 2-8% of NaOH and 0.1-1% of catalyst in a liquid ratio of 1: 2-6;

(S4) soaking: placing the forage presoaked in the step (S3) into a reaction bin, soaking for 20 hours, and draining residual liquid;

(S5) dehydration: putting the forage into a spiral dehydrator to further remove residual liquid;

(S6) primary grinding: conveying the material from which residual liquid is further removed to a first mill by a screw conveyer, mixing and adding a second liquid medicine for mixing and grinding, wherein the second liquid medicine comprises 2-4% of NaOH and 0.1-1% of catalyst in a liquid ratio of 1: 0.5-2;

(S7) secondary grinding: placing the forage subjected to primary grinding into a second grinding machine for mixing and grinding, and feeding the forage into a bin of the second grinding machine for staying for 1 hour, so as to improve the beating degree and swelling of the slurry;

(S8) three times of milling: grinding the forage which is subjected to the secondary grinding in a third grinding machine to reach the required fiber beating degree, and staying in a bin of the third grinding machine for 1 hour to obtain a semi-finished product;

(S9) washing: putting the semi-finished product after the three-time grinding into 3 series-connected dewaterers, and washing in a counter-current mode to obtain a finished product;

the (S1) to (S9) are performed at normal temperature and pressure.

Preferably, the straw is one or more of wheat straw, rice straw, reed or cotton stalk.

More preferably, the straw is a plurality of wheat straw, rice straw, reed or cotton stalk.

Particularly preferably, the raw material further comprises bamboo.

Particularly preferably, the liquid generated in the preparation process is recycled in a liquid circulation mode; the liquid circulation comprises the following steps:

(1) water collection: collecting liquid generated by the reaction bin and the dehydrator, and pumping the liquid to a micro-filter through a water collecting tank for filtering;

(2) and (3) filtering: the lost fiber filtered by the micro-filter is sent to a dehydrator for dehydration, and the dehydrated fiber by the micro-filter automatically flows into an acidification primary sedimentation tank;

(3) primary precipitation: reducing COD, BOD, SS and precipitated sludge by an acidification primary sedimentation tank, and enabling obtained supernatant to automatically overflow to an aerobic aeration tank through an upper water outlet of the acidification primary sedimentation tank;

(4) aeration: after COD, BOD and SS are reduced again in the aerobic aeration tank under the action of aeration and aerobic bacteria, the obtained supernatant automatically overflows to the reflux tank through the upper water outlet of the aerobic aeration tank for sedimentation, and then the supernatant automatically overflows to the flocculation sedimentation tank through the upper water outlet of the reflux tank;

(5) flocculation and precipitation: adding a flocculating agent into the flocculation sedimentation tank for sedimentation, and pumping supernatant into an air floatation tank;

(6) removing dirt in the air floatation tank: after sludge is scraped off in the air flotation tank, supernatant fluid automatically overflows to a reuse water tank through an upper water outlet of the air flotation tank; the dosage liquid used for the fiber extraction process is recycled, and the liquid does not need to be discharged.

One or more technical solutions provided by the present application have at least the following technical effects or advantages:

above-mentioned technical scheme, owing to adopt to cut the grass, the screening is purified, carry out after the breakage once more and carry out the normal atmospheric temperature liquid medicine circulation and spray and soak and soften 20 hours and grind a series of technological means such as utilization that combines the detention time at different grinders many times, make and grind the specific surface area that further increases the fibre through first grinder, it is favorable to the reentrant of liquid medicine to add medicine and get into the grinder and mix the heat that grinds production and further soften the fibre with the mill, after the detention time of 1 hour through the feed bin softens moist and rises once more, add medicine and get into the second grinder and mix and rub the mill, grind through the second grinder and in order to reach the used qualified fibre of production, the heat that utilizes the second grinder to grind the production further softens. The technical problems of high energy consumption, low yield and environmental pollution in the prior art are effectively solved, and the technical effects of energy conservation, environmental protection, high yield and low pollution are further realized.

Detailed Description

The following further describes the embodiments of the present invention. It should be noted that the description of the embodiments is provided to help understanding of the present invention, but the present invention is not limited thereto. In addition, the technical features involved in the embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.

According to the technical scheme of the embodiment of the application, the problems of high energy consumption, low yield and environmental pollution in the prior art are solved, and the beneficial effects of energy conservation, environmental protection, high yield and low pollution are realized under a series of technical means of cutting grass, screening, purifying, crushing again, performing normal-temperature liquid medicine circulation spraying, soaking and softening for 20 hours, grinding in different grinding machines for multiple times, combining the utilization of detention time and the like.

The general idea of the embodiment of the invention for solving the technical problems is as follows:

the method is characterized in that a series of technical means such as cutting grass, screening and purifying, crushing again, then circularly spraying and soaking the liquid medicine at normal temperature for softening for 20 hours, grinding and combining the retention time of the liquid medicine in different grinding machines for a plurality of times are adopted, so that the specific surface area of the fiber is further increased by grinding through a first grinding machine, the fiber is further immersed in the liquid medicine, adding the medicine into the grinding machine, mixing and grinding the fiber, further softening the fiber by utilizing the heat generated by grinding through the grinding machine, softening and lubricating the fiber after the retention time of the storage bin is softened for the second time, adding the medicine into a second grinding machine, mixing and grinding through the second grinding machine, grinding through the second grinding machine to achieve the qualified fiber used for production, and further softening.

The preparation method changes the conventional high-temperature and high-pressure process and saves the combustion and carbon emission of coal by cutting grass, screening, purifying, crushing again, and then circularly spraying, soaking and softening the liquid medicine at normal temperature for 20 hours. After the dehydration screw is used and the raw materials enter the metering bin to uniformly feed and dehydrate the dehydrator to control and extrude residual liquid medicine in a dry mode, the specific surface area of the fiber is further increased by rubbing and grinding through the first grinding machine, the secondary immersion of the liquid medicine is facilitated, the medicine is added to enter the first grinding machine to mix and rub and grind the fiber by utilizing the heat generated by grinding through the grinding machine, the retention time of the bin of the first grinding machine is softened and moistened again, the medicine is added to enter the second grinding machine to mix and rub and grind the fiber, the qualified fiber used for production is ground through the second grinding machine, the heat generated by grinding through the second grinding machine is further softened and moistened, and the fiber is softened again after the retention time of the bin of the second grinding machine is 1 hour, and the fiber reaches the requirements for producing decorative density boards, corrugated base paper, natural color mouth cup base. (whether enter the third and grind the machine feed bin according to the needs of the product degree of kowtowing) utilize the hydroextractor to connect in series and can get into the link that the fibre was used after the reverse washing, carry out the screening according to the requirement of low reaches use and purify.

The produced liquid is recycled after being treated by a water treatment system, and 1.5-2 tons of clear water is required to be added in the production process of each ton of fiber finished products because the final water content of the product is 75 percent.

The total alkali consumption of the preparation method is 3-12%, the mechanical grinding and softening are mainly used as main raw materials, the yield of the straw and the wheat straw is 78-85%, the yield of the cotton stalk, the reed and the bamboo is 85-92%, the method has high yield and small water treatment difficulty, and the straw and the wheat straw can be recycled after treatment. In the pretreatment stage, the process of increasing the specific surface area of the fiber and the catalyst is adopted to ensure that the forage is softened, moistened and swelled more uniformly and sufficiently, and the high-temperature and high-pressure traditional high pressure is replaced by the normal-temperature soaking for 20 hours. Therefore, the whole production process has no sewage discharge, no boiler heating and no smoke discharge. The method not only overcomes the technical bias of the prior art, but also can effectively reduce the production cost, improve the production efficiency, effectively reduce the energy consumption of production, save energy, reduce emission and be beneficial to environmental protection. Meanwhile, the product prepared by the preparation method has longer and more uniform fiber, stronger fiber bonding force, good surface flatness of the product and good ring crush index.

In order to better understand the above technical solutions, the following detailed descriptions will be provided with reference to specific embodiments.

Example 1

A preparation method of pulp fiber comprises the following steps:

(S1) cutting: the method comprises the following steps of (1) bundling straws serving as raw materials by a bundling machine, cutting the straws into straws by a straw cutter according to 3cm, and removing mineral dust and light impurities of the straws by a six-roller dust remover to obtain cut straws;

(S2) crushing: putting the cut forage obtained in the step (S1) into a crusher for further crushing so as to increase the specific surface area of the fiber;

(S3) pre-dipping: adding a first liquid medicine into the straw which is further crushed in the step (S2) by using a spiral pre-soaking machine; the first liquid medicine comprises 2-8% of NaOH and 0.1% of catalyst in a liquid ratio of 1: 2;

(S4) soaking: placing the forage presoaked in the step (S3) into a reaction bin, soaking for 20 hours, and draining residual liquid;

(S5) dehydration: putting the forage into a spiral dehydrator to further remove residual liquid;

(S6) primary grinding: conveying the material from which residual liquid is further removed to a first mill by a screw conveyer, mixing and adding a second liquid medicine for mixing and grinding, wherein the second liquid medicine comprises 2% of NaOH and 0.1% of catalyst in a liquid ratio of 1: 0.5;

(S7) secondary grinding: placing the forage subjected to primary grinding into a second grinding machine, mixing and grinding, feeding into a bin of the second grinding machine, and staying for 1 hour, and improving the beating degree and swelling of the slurry;

(S8) three times of milling: grinding the forage which is subjected to the secondary grinding in a third grinding machine to reach the required fiber beating degree, and staying in a bin of the third grinding machine for 1 hour to obtain a semi-finished product;

(S9) washing: putting the semi-finished product after the three-time grinding into 3 series-connected dewaterers, and washing in a counter-current mode to obtain a finished product;

(S1) - (S9) is carried out at normal temperature and pressure.

Specifically, the straw is selected from wheat straw, rice straw, reed and cotton stalk.

More specifically, the raw material also comprises bamboo.

Particularly preferably, the liquid generated in the preparation process is recycled in a liquid circulation mode; the liquid circulation comprises the following steps:

(1) water collection: collecting liquid generated by the reaction bin and the dehydrator, and pumping the liquid to a micro-filter through a water collecting tank for filtering;

(2) and (3) filtering: the lost fiber filtered by the micro-filter is sent to a dehydrator for dehydration, and the dehydrated fiber by the micro-filter automatically flows into an acidification primary sedimentation tank;

(3) primary precipitation: reducing COD, BOD, SS and precipitated sludge by an acidification primary sedimentation tank, and enabling obtained supernatant to automatically overflow to an aerobic aeration tank through an upper water outlet of the acidification primary sedimentation tank;

(4) aeration: after COD, BOD and SS are reduced again in the aerobic aeration tank under the action of aeration and aerobic bacteria, the obtained supernatant automatically overflows to the reflux tank through the upper water outlet of the aerobic aeration tank for sedimentation, and then the supernatant automatically overflows to the flocculation sedimentation tank through the upper water outlet of the reflux tank;

(5) flocculation and precipitation: adding a flocculating agent into the flocculation sedimentation tank for sedimentation, and pumping supernatant into an air floatation tank;

(6) removing dirt in the air floatation tank: after sludge is scraped off in the air flotation tank, supernatant fluid automatically overflows to a reuse water tank through an upper water outlet of the air flotation tank; the dosage liquid used for the fiber extraction process is recycled, and the liquid does not need to be discharged.

One or more technical solutions of this embodiment have at least the following technical effects or advantages:

above-mentioned technical scheme, owing to adopt to cut the grass, the screening is purified, carry out after the breakage once more and carry out the normal atmospheric temperature liquid medicine circulation and spray and soak and soften 20 hours and grind a series of technological means such as utilization that combines the detention time at different grinders many times, make and grind the specific surface area that further increases the fibre through first grinder, it is favorable to the reentrant of liquid medicine to add medicine and get into the grinder and mix the heat that grinds production and further soften the fibre with the mill, after the detention time of 1 hour through the feed bin softens moist and rises once more, add medicine and get into the second grinder and mix and rub the mill, grind through the second grinder and in order to reach the used qualified fibre of production, the heat that utilizes the second grinder to grind the production further softens. The technical problems of high energy consumption, low yield and environmental pollution in the prior art are effectively solved, and the technical effects of energy conservation, environmental protection, high yield and low pollution are further realized.

Example 2

A preparation method of pulp fiber comprises the following steps:

(S1) cutting: the method comprises the following steps of (1) bundling straws serving as raw materials by a bundling machine, cutting the straws into a straw cutter according to 3.5cm, removing mineral dust and light impurities of the straws by a six-roller dust remover to obtain cut straws;

(S2) crushing: putting the cut forage obtained in the step (S1) into a crusher for further crushing so as to increase the specific surface area of the fiber;

(S3) pre-dipping: adding a first liquid medicine into the straw which is further crushed in the step (S2) by using a spiral pre-soaking machine; the first liquid medicine comprises 1-8% of NaOH and 0.5% of catalyst in a liquid ratio of 1: 4;

(S4) soaking: placing the forage presoaked in the step (S3) into a reaction bin, soaking for 20 hours, and draining residual liquid;

(S5) dehydration: putting the forage into a spiral dehydrator to further remove residual liquid;

(S6) primary grinding: conveying the material from which residual liquid is further removed to a first mill by a screw, mixing and adding a second liquid medicine, mixing and grinding, wherein the second liquid medicine comprises 1-8% of NaOH and 0.5% of catalyst in a liquid ratio of 1: 1.5;

(S7) secondary grinding: placing the forage subjected to primary grinding into a second grinding machine, mixing and grinding, feeding into a bin of the second grinding machine, and staying for 1 hour, and improving the beating degree and swelling of the slurry;

(S8) three times of milling: grinding the forage which is subjected to the secondary grinding in a third grinding machine to reach the required fiber beating degree, and staying in a bin of the third grinding machine for 1 hour to obtain a semi-finished product;

(S9) washing: putting the semi-finished product after the three-time grinding into 3 series-connected dewaterers, and washing in a counter-current mode to obtain a finished product;

(S1) - (S9) is carried out at normal temperature and pressure.

Specifically, the straw is selected from wheat straw, rice straw, reed and cotton stalk.

More specifically, the raw material also comprises bamboo.

Particularly preferably, the liquid generated in the preparation process is recycled in a liquid circulation mode; the liquid circulation comprises the following steps:

(1) water collection: collecting liquid generated by the reaction bin and the dehydrator, and pumping the liquid to a micro-filter through a water collecting tank for filtering;

(2) and (3) filtering: the lost fiber filtered by the micro-filter is sent to a dehydrator for dehydration, and the dehydrated fiber by the micro-filter automatically flows into an acidification primary sedimentation tank;

(3) primary precipitation: reducing COD, BOD, SS and precipitated sludge by an acidification primary sedimentation tank, and enabling obtained supernatant to automatically overflow to an aerobic aeration tank through an upper water outlet of the acidification primary sedimentation tank;

(4) aeration: after COD, BOD and SS are reduced again in the aerobic aeration tank under the action of aeration and aerobic bacteria, the obtained supernatant automatically overflows to the reflux tank through the upper water outlet of the aerobic aeration tank for sedimentation, and then the supernatant automatically overflows to the flocculation sedimentation tank through the upper water outlet of the reflux tank;

(5) flocculation and precipitation: adding a flocculating agent into the flocculation sedimentation tank for sedimentation, and pumping supernatant into an air floatation tank;

(6) removing dirt in the air floatation tank: after sludge is scraped off in the air flotation tank, supernatant fluid automatically overflows to a reuse water tank through an upper water outlet of the air flotation tank; the dosage liquid used for the fiber extraction process is recycled, and the liquid does not need to be discharged.

One or more technical solutions of this embodiment have at least the following technical effects or advantages:

above-mentioned technical scheme, owing to adopt to cut the grass, the screening is purified, carry out after the breakage once more and carry out the normal atmospheric temperature liquid medicine circulation and spray and soak and soften 20 hours and grind a series of technological means such as utilization that combines the detention time at different grinders many times, make and grind the specific surface area that further increases the fibre through first grinder, it is favorable to the reentrant of liquid medicine to add medicine and get into the grinder and mix the heat that grinds production and further soften the fibre with the mill, after the detention time of 1 hour through the feed bin softens moist and rises once more, add medicine and get into the second grinder and mix and rub the mill, grind through the second grinder and in order to reach the used qualified fibre of production, the heat that utilizes the second grinder to grind the production further softens. The technical problems of high energy consumption, low yield and environmental pollution in the prior art are effectively solved, and the technical effects of energy conservation, environmental protection, high yield and low pollution are further realized.

Example 3

A preparation method of pulp fiber comprises the following steps:

(S1) cutting: the method comprises the following steps of (1) bundling straws serving as raw materials by a bundling machine, cutting the straws into a straw cutter according to 4cm, and removing mineral dust and light impurities of the straws by a six-roller dust remover to obtain cut straws;

(S2) crushing: putting the cut forage obtained in the step (S1) into a crusher for further crushing so as to increase the specific surface area of the fiber;

(S3) pre-dipping: adding a first liquid medicine into the straw which is further crushed in the step (S2) by using a spiral pre-soaking machine; the first liquid medicine comprises 2-8% of NaOH and 1% of catalyst in a liquid ratio of 1: 6;

(S4) soaking: placing the forage presoaked in the step (S3) into a reaction bin, soaking for 20 hours, and draining residual liquid;

(S5) dehydration: putting the forage into a spiral dehydrator to further remove residual liquid;

(S6) primary grinding: conveying the material from which residual liquid is further removed to a first mill by a screw conveyer, mixing, adding a second liquid medicine, mixing and grinding, wherein the second liquid medicine comprises 1-8% of NaOH and 1% of catalyst in a liquid ratio of 1: 2;

(S7) secondary grinding: placing the forage subjected to primary grinding into a second grinding machine, mixing and grinding, feeding into a bin of the second grinding machine, and staying for 1 hour, and improving the beating degree and swelling of the slurry;

(S8) three times of milling: grinding the forage which is subjected to the secondary grinding in a third grinding machine to reach the required fiber beating degree, and staying in a bin of the third grinding machine for 1 hour to obtain a semi-finished product;

(S9) washing: putting the semi-finished product after the three-time grinding into 3 series-connected dewaterers, and washing in a counter-current mode to obtain a finished product;

(S1) - (S9) is carried out at normal temperature and pressure.

Specifically, the straw is selected from wheat straw, rice straw, reed and cotton stalk.

More specifically, the raw material also comprises bamboo.

Particularly preferably, the liquid generated in the preparation process is recycled in a liquid circulation mode; the liquid circulation comprises the following steps:

(1) water collection: collecting liquid generated by the reaction bin and the dehydrator, and pumping the liquid to a micro-filter through a water collecting tank for filtering;

(2) and (3) filtering: the lost fiber filtered by the micro-filter is sent to a dehydrator for dehydration, and the dehydrated fiber by the micro-filter automatically flows into an acidification primary sedimentation tank;

(3) primary precipitation: COD, BOD, SS and precipitated sludge are reduced by the acid precipitation primary sedimentation tank, and the obtained supernatant is pumped to the anaerobic tower through the upper water outlet of the acid precipitation primary sedimentation tank and automatically overflows to the aerobic aeration tank;

(4) aeration: after COD, BOD and SS are reduced again in the aerobic aeration tank under the action of aeration and aerobic bacteria, the obtained supernatant automatically overflows to the reflux tank through the upper water outlet of the aerobic aeration tank for sedimentation, and then the supernatant automatically overflows to the flocculation sedimentation tank through the upper water outlet of the reflux tank;

(5) flocculation and precipitation: adding a flocculating agent into the flocculation sedimentation tank for sedimentation, and pumping supernatant into an air floatation tank;

(6) removing dirt in the air floatation tank: after sludge is scraped off in the air flotation tank, supernatant fluid automatically overflows to a reuse water tank through an upper water outlet of the air flotation tank; the dosage liquid used for the fiber extraction process is recycled, and the liquid does not need to be discharged.

One or more technical solutions of this embodiment have at least the following technical effects or advantages:

above-mentioned technical scheme, owing to adopt to cut the grass, the screening is purified, carry out after the breakage once more and carry out the normal atmospheric temperature liquid medicine circulation and spray and soak and soften 20 hours and grind a series of technological means such as utilization that combines the detention time at different grinders many times, make and grind the specific surface area that further increases the fibre through first grinder, it is favorable to the reentrant of liquid medicine to add medicine and get into the grinder and mix the heat that grinds production and further soften the fibre with the mill, after the detention time of 1 hour through the feed bin softens moist and rises once more, add medicine and get into the second grinder and mix and rub the mill, grind through the second grinder and in order to reach the used qualified fibre of production, the heat that utilizes the second grinder to grind the production further softens. The technical problems of high energy consumption, low yield and environmental pollution in the prior art are effectively solved, and the technical effects of energy conservation, environmental protection, high yield and low pollution are further realized.

Comparison of examples 1-3 with the prior art:

the technological parameters of the prior art are as follows:

1. high temperature and high pressure (0.6-0.7 mpa),

2. strong alkali 12-16% (NaOH), about 65% more alkali extract,

3. the black liquor is difficult to treat,

4. the yield is low (35%),

5. high water consumption of 100 ton/ton pulp

6. High pollution

The embodiment of the application has the following comparative advantages:

01. normal temperature and pressure to reduce energy consumption

02. Less alkali (NaOH 2-8%)

03. Liquid recovery with reduced emissions

04. High yield (more than 78 percent)

05. Low water consumption (because the final water content of the product is 75 percent, 1.5 to 2 tons of clean water are needed to be added in the production process of each ton of fiber finished product.)

06. Low pollution

The embodiments of the present invention have been described in detail, but the present invention is not limited to the described embodiments. It will be apparent to those skilled in the art that various changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the invention, and the scope of protection is still within the scope of the invention.