阅读说明：本技术 一种干损纸的回收工艺 (Recovery process of dry broke ) 是由 李文斌 于 2020-12-31 设计创作，主要内容包括：本发明公开了一种干损纸的回收工艺。包括以下步骤：(1)干损纸预处理；(2)进一步处理；(3)使用。本发明的回收工艺采用解离剂将干损纸表面的胶黏剂从干损纸表面剥离,从而方便干损纸成浆,再采用絮凝剂将胶黏剂沉淀,过滤之后,得到能够直接利用的纸浆,纸浆直接泵送至混合浆池,减少了再一次筛选、净化、浓缩、热分散等处理流程,有效降低能耗,同时减少了纤维流失。(The invention discloses a recovery process of dry broke. The method comprises the following steps: (1) pretreating dry broke; (2) further processing; (3) the preparation is used. According to the recovery process, the adhesive on the surface of the dry broke is stripped from the surface of the dry broke by using the dissociating agent, so that the dry broke is convenient to form pulp, the adhesive is precipitated by using the flocculating agent, the pulp capable of being directly utilized is obtained after filtration, and the pulp is directly pumped to the mixed pulp tank, so that the treatment processes of secondary screening, purification, concentration, thermal dispersion and the like are reduced, the energy consumption is effectively reduced, and the fiber loss is reduced.)

1. A recovery process of dry broke is characterized by comprising the following steps:

(1) pretreatment of dry broke: collecting dry broke produced in the papermaking process, soaking and breaking the dry broke into pulp to obtain broke pulp;

(2) and (3) further processing: adding a dissociating agent into the damaged paper pulp, stirring and mixing, then adding a flocculating agent, fully mixing, and filtering to obtain paper pulp; the dissociation agent comprises aluminum oxide, hydrogen peroxide, sodium carboxymethylcellulose and water;

(3) use of: and (3) directly pumping the paper pulp obtained in the step (2) to a mixed pulp tank, mixing the paper pulp with the normally processed paper pulp, and then carrying out papermaking operation.

2. The recycling process of dry broke according to claim 1, wherein the debonding agent comprises the following raw materials in parts by weight: 10-15 parts of alumina, 40-50 parts of hydrogen peroxide, 3-8 parts of sodium carboxymethylcellulose and 120 parts of water.

3. The process according to claim 2, wherein the debonding agent is added in an amount of 10-15 kg/ton dry broke.

4. The recycling process of dry broke according to claim 1, characterized in that the flocculant comprises the following raw materials in parts by weight: 15-25 parts of polyacrylamide, 10-15 parts of stearamide and 10-15 parts of modified diatomite.

5. The process according to claim 4, characterized in that said modified starch is obtained by the following steps: soaking the diatomite in a sulfuric acid solution for 30-40min, filtering, adding the filtered diatomite, acrylic acid grafted starch and water, mixing under an ultrasonic condition, centrifugally filtering, then placing the mixture in a roasting furnace for roasting, and cooling to obtain the modified diatomite.

6. The process according to claim 5, characterized in that said acrylic acid grafted starch is obtained by the following steps: mixing starch and water at 60-80 deg.C for 30-40min, maintaining the temperature at 60-80 deg.C, adding acrylic acid, reacting under shaking for 60-80min, and oven drying at 90-100 deg.C to obtain acrylic acid grafted starch; the weight portions of the water and the acrylic acid are respectively 120 portions and 50-60 portions based on 100 portions of the starch.

7. The recycling process of dry broke according to claim 4 or 5, wherein the weight parts of the diatomite are 100 parts, and the weight parts of the other raw materials are respectively as follows: 30-40 parts of acrylic acid grafted starch and 300 parts of water.

8. A process according to claim 4 or 5, characterized in that the flocculant is added in an amount of 10-12 kg per ton of dry broke.

Technical Field

The invention relates to a recovery process of dry broke, belonging to the technical field of papermaking.

Background

The papermaking system can produce two types of broke, namely dry broke and wet broke, wherein the wet broke is broke produced at a forming wire couch roll, and the dry broke is broke produced in a press section and subsequent sections of a paper machine. The wet broke has high water content because of not being dried, and the fibers are mainly combined together under the action of weak hydrogen bonds, so the wet broke has low strength and is easy to process. The dry broke has the moisture evaporated due to the drying effect, the distance between fiber hydroxyl groups is greatly shortened, the hydroxyl groups also complete the process of directional arrangement, and the condition of forming hydrogen bond bonding force is provided. Under the auxiliary action of hydrogen bonds, other binding forces and chemicals, the strength, tightness and water resistance of the dry broke are greatly improved, and the treatment of the dry broke becomes difficult.

If the dry broke can be returned to the papermaking process again, on one hand, the production cost of paper is reduced, and the waste is reduced; on the other hand, the consumption of fresh pulp can be reduced, and resources are saved, so that a recovery process of dry broke is necessary.

Disclosure of Invention

In order to overcome the defects of the prior art, the invention provides a dry broke recycling process.

The invention is realized by the following technical scheme:

a process for recycling dry broke, comprising the steps of:

(1) pretreatment of dry broke: collecting dry broke produced in the papermaking process, soaking and breaking the dry broke into pulp to obtain broke pulp;

(2) and (3) further processing: adding a dissociating agent into the damaged paper pulp, stirring and mixing, then adding a flocculating agent, fully mixing, and filtering to obtain paper pulp; the dissociation agent comprises aluminum oxide, hydrogen peroxide, sodium carboxymethylcellulose and water;

(3) use of: and (3) directly pumping the paper pulp obtained in the step (2) to a mixed pulp tank, mixing the paper pulp with the normally processed paper pulp, and then carrying out papermaking operation.

The recovery process of the dry broke paper comprises the following raw materials in parts by weight: 10-15 parts of alumina, 40-50 parts of hydrogen peroxide, 3-8 parts of sodium carboxymethylcellulose and 120 parts of water.

According to the dry broke recovery process, the addition amount of the dissociation agent is 10-15 kg/ton of dry broke.

The recovery process of the dry broke comprises the following raw materials in parts by weight: 15-25 parts of polyacrylamide, 10-15 parts of stearamide and 10-15 parts of modified diatomite.

The recovery process of the dry broke paper comprises the following steps of: soaking the diatomite in a sulfuric acid solution for 30-40min, filtering, adding the filtered diatomite, acrylic acid grafted starch and water, mixing under an ultrasonic condition, centrifugally filtering, then placing the mixture in a roasting furnace for roasting, and cooling to obtain the modified diatomite.

The recovery process of the dry broke paper comprises the following steps of: mixing starch and water at 60-80 deg.C for 30-40min, maintaining the temperature at 60-80 deg.C, adding acrylic acid, reacting under shaking for 60-80min, and oven drying at 90-100 deg.C to obtain acrylic acid grafted starch; the weight portions of the water and the acrylic acid are respectively 120 portions and 50-60 portions based on 100 portions of the starch.

The recovery process of the dry broke paper comprises the following raw materials in parts by weight, based on 100 parts by weight of diatomite: 30-40 parts of acrylic acid grafted starch and 300 parts of water.

According to the recovery process of the dry broke, the addition amount of the flocculating agent is 10-12 kg/ton of dry broke.

The invention achieves the following beneficial effects:

according to the recovery process, the adhesive on the surface of the dry broke is stripped from the surface of the dry broke by using the dissociating agent, so that the dry broke is convenient to form pulp, the adhesive is precipitated by using the flocculating agent, the pulp capable of being directly utilized is obtained after filtration, and the pulp is directly pumped to the mixed pulp tank, so that the treatment processes of secondary screening, purification, concentration, thermal dispersion and the like are reduced, the energy consumption is effectively reduced, and the fiber loss is reduced.

The recovery process of the invention is adopted to recover the dry broke, the secondary utilization rate of the dry broke is improved, the unit consumption of raw materials of the waste paper is reduced by 2 percent, the power consumption is reduced by about 50 percent, the annual power consumption is saved by about 180 ten thousand yuan, and the quality of the finished paper meets the requirements of the national standard GB/T13024-one 2016.

Detailed Description

The invention is further described below. The following examples are only for illustrating the technical solutions of the present invention more clearly, and the protection scope of the present invention is not limited thereby.

Example 1

A process for recycling dry broke, comprising the steps of:

(1) pretreatment of dry broke: collecting dry broke produced in the papermaking process, soaking and breaking the dry broke into pulp to obtain broke pulp;

(2) and (3) further processing: adding a dissociating agent into the damaged paper pulp, stirring and mixing, then adding a flocculating agent, fully mixing, and filtering to obtain paper pulp; the dissociation agent comprises aluminum oxide, hydrogen peroxide, sodium carboxymethylcellulose and water;

(3) use of: and (3) directly pumping the paper pulp obtained in the step (2) to a mixed pulp tank, mixing the paper pulp with the normally processed paper pulp, and then carrying out papermaking operation.

The dissociation agent comprises the following raw materials in parts by weight: 10 parts of aluminum oxide, 40 parts of hydrogen peroxide, 8 parts of sodium carboxymethylcellulose and 100 parts of water. The addition of the debonding agent was 15 kg/ton dry broke.

The flocculant comprises the following raw materials in parts by weight: 15 parts of polyacrylamide, 10 parts of stearamide and 15 parts of modified diatomite. The addition of the flocculant is 10kg per ton of dry broke.

The modified starch is obtained by the following steps: soaking the diatomite in a sulfuric acid solution for 30-40min, filtering, adding the filtered diatomite, acrylic acid grafted starch and water, mixing under an ultrasonic condition, centrifugally filtering, then placing the mixture in a roasting furnace for roasting, and cooling to obtain the modified diatomite. The diatomite is 100 parts by weight, and the rest raw materials are respectively as follows: 30 parts of acrylic acid grafted starch and 200 parts of water.

The acrylic acid grafted starch is obtained by the following steps: mixing starch and water at 60-80 deg.C for 30-40min, maintaining the temperature at 60-80 deg.C, adding acrylic acid, reacting under shaking for 60-80min, and oven drying at 90-100 deg.C to obtain acrylic acid grafted starch; the weight parts of the water and the acrylic acid are respectively 100 parts and 50 parts based on 100 parts of the starch.

The dissociation agent of the invention uses hydrogen peroxide and alumina to strip the adhesive on the surface of the dry broke paper, strips the adhesive on the surface of the dry broke paper from the surface of the dry broke paper, adopts sodium carboxymethyl cellulose to disperse the stripped adhesive, and is convenient for the fiber of the dry broke paper to be scattered

The flocculating agent disclosed by the invention adopts polyacrylamide, stearamide and modified diatomite, has a good flocculating effect, can precipitate an adhesive, is treated by acid and then treated by acrylic acid grafted starch, has a large specific surface area, is matched with the acrylic acid grafted starch with good adhesion, and can adsorb the adhesive. The acrylic acid grafted starch of the invention has simple preparation and good adhesion.

Example 2

A process for recycling dry broke, comprising the steps of:

(1) pretreatment of dry broke: collecting dry broke produced in the papermaking process, soaking and breaking the dry broke into pulp to obtain broke pulp;

(2) and (3) further processing: adding a dissociating agent into the damaged paper pulp, stirring and mixing, then adding a flocculating agent, fully mixing, and filtering to obtain paper pulp; the dissociation agent comprises aluminum oxide, hydrogen peroxide, sodium carboxymethylcellulose and water;

(3) use of: and (3) directly pumping the paper pulp obtained in the step (2) to a mixed pulp tank, mixing the paper pulp with the normally processed paper pulp, and then carrying out papermaking operation.

The dissociation agent comprises the following raw materials in parts by weight: 15 parts of aluminum oxide, 50 parts of hydrogen peroxide, 3 parts of sodium carboxymethylcellulose and 120 parts of water. The addition of the debonding agent was 10 kg/ton dry broke.

The flocculant comprises the following raw materials in parts by weight: 25 parts of polyacrylamide, 15 parts of stearamide and 10 parts of modified diatomite. The addition of the flocculant is 12 kg per ton of dry broke.

The modified starch is obtained by the following steps: soaking the diatomite in a sulfuric acid solution for 30-40min, filtering, adding the filtered diatomite, acrylic acid grafted starch and water, mixing under an ultrasonic condition, centrifugally filtering, then placing the mixture in a roasting furnace for roasting, and cooling to obtain the modified diatomite. The diatomite is 100 parts by weight, and the rest raw materials are respectively as follows: 40 parts of acrylic acid grafted starch and 300 parts of water.

The acrylic acid grafted starch is obtained by the following steps: mixing starch and water at 60-80 deg.C for 30-40min, maintaining the temperature at 60-80 deg.C, adding acrylic acid, reacting under shaking for 60-80min, and oven drying at 90-100 deg.C to obtain acrylic acid grafted starch; the weight portions of the water and the acrylic acid are respectively 120 parts and 60 parts based on 100 parts of the starch.

Example 3

A process for recycling dry broke, comprising the steps of:

(1) pretreatment of dry broke: collecting dry broke produced in the papermaking process, soaking and breaking the dry broke into pulp to obtain broke pulp;

(2) and (3) further processing: adding a dissociating agent into the damaged paper pulp, stirring and mixing, then adding a flocculating agent, fully mixing, and filtering to obtain paper pulp; the dissociation agent comprises aluminum oxide, hydrogen peroxide, sodium carboxymethylcellulose and water;

(3) use of: and (3) directly pumping the paper pulp obtained in the step (2) to a mixed pulp tank, mixing the paper pulp with the normally processed paper pulp, and then carrying out papermaking operation.

The dissociation agent comprises the following raw materials in parts by weight: 12 parts of aluminum oxide, 45 parts of hydrogen peroxide, 5 parts of sodium carboxymethylcellulose and 110 parts of water. The addition of the debonding agent was 11 kg/ton dry broke.

The flocculant comprises the following raw materials in parts by weight: 20 parts of polyacrylamide, 12 parts of stearamide and 12 parts of modified diatomite. The addition of the flocculant is 11 kg/ton dry broke.

The modified starch is obtained by the following steps: soaking the diatomite in a sulfuric acid solution for 30-40min, filtering, adding the filtered diatomite, acrylic acid grafted starch and water, mixing under an ultrasonic condition, centrifugally filtering, then placing the mixture in a roasting furnace for roasting, and cooling to obtain the modified diatomite. The diatomite is 100 parts by weight, and the rest raw materials are respectively as follows: 35 parts of acrylic acid grafted starch and 280 parts of water.

The acrylic acid grafted starch is obtained by the following steps: mixing starch and water at 60-80 deg.C for 30-40min, maintaining the temperature at 60-80 deg.C, adding acrylic acid, reacting under shaking for 60-80min, and oven drying at 90-100 deg.C to obtain acrylic acid grafted starch; the weight portions of the water and the acrylic acid are respectively 110 parts and 55 parts based on 100 parts of the starch.

The above description is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, several modifications and variations can be made without departing from the technical principle of the present invention, and these modifications and variations should also be regarded as the protection scope of the present invention.