WO2021016860A1

WO2021016860A1 - Paper faced gypsum board and preparation method therefor

Info

Publication number: WO2021016860A1
Application number: PCT/CN2019/098365
Authority: WO
Inventors: 尹东杰; 王鹏起; 谭丹君; 王莹; 简铭; 何亮; 武发德
Original assignee: 北新集团建材股份有限公司
Priority date: 2019-07-30
Filing date: 2019-07-30
Publication date: 2021-02-04

Abstract

A paper faced gypsum board, comprising: desulfuration gypsum, water, calcium oxide, sodium metaaluminate, crown ether, glass fiber, a retarder, and starch. Further provided is a preparation method for the paper faced gypsum board. The paper faced gypsum board can be prepared from low-grade desulfuration gypsum, and the physical performance of the paper faced gypsum board is excellent so that the utilization of the low-grade desulfuration gypsum is implemented.

Description

Paper-faced gypsum board and preparation method thereof

Technical field

This application relates to but not limited to the field of building materials, and particularly relates to but not limited to a paper-faced gypsum board and a preparation method thereof.

Background technique

Desulfurized gypsum is the product of flue gas desulfurization in coal-fired power plants. With the promotion of flue gas desulfurization projects in coal-fired power plants, the annual output of desulfurized gypsum in my country is amazing. Desulfurized gypsum is widely used in building materials and other industries, which promotes the further development of the country's environmental protection and circular economy, and also greatly reduces the amount of natural gypsum mining and protects resources.

At present, the technology of using desulfurized gypsum to prepare gypsum board is relatively mature, but the unstable quality of gypsum will still affect the quality of gypsum board. From the analysis of chemical composition, desulfurized gypsum mainly includes CaO, SO ₃ ^2- , and also includes Na ₂ O, K ₂ O, MgO, Cl ^- and other impurities. Excessive water-soluble salt will cause quality problems such as adhesion, swelling, and anti-alkali to gypsum products. In a humid environment, moisture absorption and crystallization of water-soluble salt will affect the bonding of gypsum board cover paper and board core. . Chloride ions can form a stable substance containing crystal water with Ca ²⁺ and Mg ²⁺ , making desulfurized gypsum difficult to dehydrate, affecting the calcining temperature and calcining quality of desulfurized gypsum; at the same time, high chloride ion content will reduce the surface protection paper and The bonding performance of the board core affects the application of gypsum board.

The raw materials for desulfurization gypsum produced by Chinese power plants are generally of low quality, with large differences in quality and different product performance. Therefore, all paper-faced gypsum board manufacturers strictly test the chloride ion content when the desulfurization gypsum enters the plant. limited use.

Summary of the invention

The following is an overview of the topics detailed in this article. This summary is not intended to limit the scope of protection of the claims.

The present application provides a paper-faced gypsum board and a preparation method thereof. The paper-faced gypsum board can be prepared by using low-quality desulfurized gypsum, which expands the application range of the main raw material for producing the paper-faced gypsum board, the desulfurized gypsum.

This application provides a paper-faced gypsum board, which includes: desulfurized gypsum, water, calcium oxide, metaaluminate, cyclic ether cationic complex, glass fiber, retarder and starch, Wherein, the metaaluminate is selected from any one or more of alkali metal metaaluminate and alkaline earth metal metaaluminate, and the cyclic ether cation complex is selected from crown ethers and cavities. Any one or more of ethers.

In an embodiment of the present application, the gypsum board may include: based on 100 parts by weight of desulfurized gypsum, 55 parts by weight to 70 parts by weight of water, 0.0005 parts by weight to 0.002 parts by weight of calcium oxide, 0.0005 parts by weight of metaaluminate Parts by weight to 0.002 parts by weight, cyclic ether cationic complex from 0.0002 parts by weight to 0.0005 parts by weight, glass fiber 0.05 parts by weight to 0.2 parts by weight, retarder 0.2 parts by weight to 1 part by weight, starch 0.2 parts by weight to 1 part by weight Parts by weight.

In the embodiment of the present application, the desulfurized gypsum may be flue gas desulfurized gypsum with a dry basis content of chloride ions in the range of 400 mg/kg to 6000 mg/kg (according to the People’s Republic of China Building Materials Industry Standard JC/T 2074-2011 "Flue Gas Desulfurization Gypsum", the technical requirements for three-level desulfurization gypsum stipulate: the dry basis content of chloride ions ≤ 400mg/kg).

In the embodiment of the present application, the grade of the desulfurized gypsum (that is, the mass percentage of calcium sulfate dihydrate in the dry-based desulfurized gypsum) may be 80% to 100%, and the dry-based content of water-soluble magnesium oxide may be ≤0.08% , The dry basis content of water-soluble sodium oxide can be ≤0.20% (according to JC/T 2074-2011 "flue gas desulfurization gypsum", the technical requirements of tertiary desulfurization gypsum stipulate: the dry basis content of calcium sulfate dihydrate is ≥85%, water soluble The dry basis content of magnesia ≤0.08%, water-soluble sodium oxide ≤0.20%). The general factory limits the grade of desulfurized gypsum above 90%, and the chloride ion content is limited to less than 300ppm. In this application, the grade of the desulfurized gypsum, the dry basis content of the water-soluble magnesium oxide, and the dry basis content of the water-soluble sodium oxide are the same as those of JC/T 2074-2011 "Flue Gas Desulfurization Gypsum" Representation method, in terms of mass score.

In an embodiment of the present application, a specific surface area of the gypsum may be 3500cm ² / g to 4000cm ² / g.

In the embodiment of the present application, the crown ether can be selected from any one or two of 18-crown-6 and 15-crown-5.

In the embodiment of the present application, the cryptate can be selected from any one of cryptate [1,1,1], cryptate [2,2,1] and cryptate [2,2,2] or Many kinds.

In the embodiments of the present application, the metaaluminate may be selected from any one or more of sodium metaaluminate, potassium metaaluminate and magnesium metaaluminate.

In the embodiments of the present application, the glass fiber may be selected from any one or more of medium-alkali glass fibers, alkali-free glass fibers and alkali-resistant glass fibers.

In the embodiment of the present application, the fiber length of the glass fiber may be 9 mm to 15 mm, and the fiber monofilament diameter may be 10 μm to 15 μm.

In the embodiments of the present application, the retarder may be selected from any one or more of citric acid, sodium citrate, sodium hexametaphosphate, borax and protein retarders.

In the embodiments of the present application, the protein-based retarder may include a bone glue protein retarder and a protein-based gypsum retarder formed by calcium salting of degraded polyamide.

In the embodiment of the present application, the paper-faced gypsum board may also include a foaming agent and a pure aldehyde agent, and based on 100 parts by weight of desulfurized gypsum, the foaming agent is 0.1 to 2 parts by weight, The aldehyde agent is 0.5 to 5 parts by weight.

As a bulk building material, gypsum board is widely used in interior decoration. It is necessary to develop plasterboard with formaldehyde purification function. At present, the pure aldehyde gypsum board realizes its aldehyde purification function mainly by mixing adsorption substances or spraying photocatalyst materials. Simple adsorption can reduce the formaldehyde content in a short time, but there is the problem of secondary release of pollution sources after the adsorption is saturated. This application aims to solve the problem of formaldehyde adsorption in the plasterboard by adding a pure formaldehyde agent to the plasterboard After being saturated, it will be released into the air again and endanger human health.

In the embodiment of the present application, the aldehyde scavenger may be selected from any one or more of titanium dioxide, tetrapod-shaped zinc oxide whiskers, tin oxide and cadmium sulfide.

The application also provides a method for preparing the gypsum board as described above, and the preparation method includes:

Step 1. Weigh desulfurized gypsum and glass fiber and mix them evenly;

Step 2. Optionally, mix the foaming agent and the clean aldehyde agent evenly;

Step 3: Weigh water, retarder, starch, cyclic ether cationic complex, calcium oxide, and metaaluminate, and mix them evenly to obtain a mixed solution;

Step 4. Add the mixture obtained in step one to the mixture obtained in step three, and optionally, add the mixture obtained in step two to make a gypsum slurry;

Step 5: Attach masking paper to the upper and lower surfaces of the evenly stirred gypsum slurry and shape it;

Step 6. The formed wet plate is solidified and dried after being cut;

Step 7. The dried boards are combined, sawed, sealed and packaged to form the gypsum board.

In the embodiment of the present application, the step 5 may include: throwing the evenly stirred gypsum slurry onto the face protection paper under the action of centrifugal force, and then squeezing it with a forming knife, after folding the face protection paper into a right angle, The forming plate is squeezed and overlapped with another face protection paper and adhered firmly to form a wet plate, and then the wet plate is drawn out to complete the forming.

In the embodiment of the present application, the evenly stirred slurry can be thrown onto the lower surface protection paper on the forming table under the action of centrifugal force, and the slurry is squeezed by the forming knife under the traction force of the solidification belt to make the lower surface protection After the paper is folded at right angles along the roller traces, the lower protective paper and the slurry are lapped with the upper protective paper under the squeeze of the forming plate and adhered firmly to form a wet plate, and then the wet plate is drawn on the solidified belt The bottom is led out and the molding is completed.

In the embodiment of the present application, the drying in step 6 may include three drying stages: 180°C to 155°C, 100°C to 130°C, and 45°C to 60°C.

The gypsum board of the present application can be prepared by using low-quality desulfurized gypsum with high water-soluble salt content. The hole molecular structure of crown ether or cryptether complexes alkali metal ions; calcium oxide and sodium metaaluminate react with water-soluble chloride ions in gypsum slurry to produce calcium aluminum chloride layered compound Ca ₄ Al with extremely small solubility ₂ Cl ₂ (OH) ₁₂ to remove magnesium oxide, sodium oxide and chloride ions.

The paper-faced gypsum board prepared by this application has reached national standards in terms of single weight, longitudinal breaking load, transverse breaking load, peeling of the protective paper and core material, edge hardness, end hardness, and bonding performance, and even better than the market. The ordinary paper-faced gypsum board above realizes the use of low-quality desulfurized gypsum.

When the gypsum board of the present application contains an aldehyde detergent, it can effectively purify the formaldehyde in the room, and the purification effect is long-lasting.

Other features and advantages of the present application will be described in the following description, and partly become obvious from the description, or understood by implementing the present application. The purpose and other advantages of this application can be realized and obtained through the structures specifically pointed out in the specification and claims.

Detail

In order to make the purpose, technical solutions, and advantages of the present application clearer, the embodiments of the present application will be described in detail below. It should be noted that the embodiments in this application and the features in the embodiments can be combined with each other arbitrarily if there is no conflict.

In the following examples, the desulfurized gypsum clinker used is made of solid waste desulfurized gypsum produced by power plant flue gas desulfurization; the glass fiber was purchased from Beijing Hangzhou Mineral Products Co., Ltd., and is an alkali-free glass fiber with a fiber length of 10 mm. The fiber monofilament diameter is 10μm; crown ether, calcium oxide and sodium metaaluminate are purchased from Sinopharm Chemical Reagent Co., Ltd.; modified starch is purchased from Jinan Yuantong Chemical Co., Ltd.; retarder is made of degraded polyamide by calcium salting Protein gypsum retarder—Italy SICIT2000 gypsum retarder Plast Retard PE, purchased from Shanghai Qinhe Chemical Co., Ltd.; the foaming agent is sodium bicarbonate, purchased from Jinan Yihao Chemical Co., Ltd., and the aldehyde agent is four injections Shaped zinc oxide whiskers.

Example 1

The grade of desulfurized gypsum is 84% and the specific surface area is 3587cm ² /g. The dry basis content of water-soluble magnesium oxide is 0.08%, the dry basis content of water-soluble sodium oxide is 0.19%, and the dry basis content of chloride ion is 1000mg/kg.

The specific steps for preparing gypsum board are as follows:

Step 1. Weigh 100 parts by weight of desulfurized gypsum and 0.06 parts by weight of glass fiber, mechanically stir and mix uniformly.

Step 2. Weigh 57 parts by weight of water, 0.8 parts by weight of retarder, 0.3 parts by weight of modified starch, 18-crown ether-6, 0.0003 parts by weight, 0.0006 parts by weight of calcium oxide, 0.0006 parts by weight of sodium metaaluminate, and mix well .

Step 3: Add the mixture of desulfurized gypsum and glass fiber obtained in Step 1 to the mixed solution obtained in Step 2 to prepare a gypsum slurry.

Step 4. Throw the evenly stirred slurry onto the lower masking paper on the forming table under the action of centrifugal force. The slurry is squeezed by the forming knife under the traction force of the solidification belt to make the lower masking paper roll along its roll After the traces are folded at a right angle, the lower protective paper and the slurry are lapped with the upper protective paper under the squeeze of the forming plate, and glued to form a wet plate, and then the wet plate is pulled by the solidified belt Lead out and complete the molding.

Step 5. The wet plate is solidified on the conveyor belt, and after being cut, it enters the dryer and goes through three drying stages at 180°C, 110°C and 45°C.

Step 6: The dried boards are combined, sawed, sealed, and packaged to form gypsum board.

Example 2

The grade of desulfurized gypsum is 82%, and the specific surface area is 3873cm ² /g. The dry basis content of water-soluble magnesium oxide is 0.06%, the dry basis content of water-soluble sodium oxide is 0.12%, and the dry basis content of chloride ion is 3000mg/kg.

The specific steps for preparing gypsum board are as follows:

Step 1: Weigh 100 parts by weight of desulfurized gypsum and 0.18 parts by weight of glass fiber, mechanically stir and mix uniformly.

Step 2. Weigh 65 parts by weight of water, 0.5 parts by weight of retarder, 0.5 parts by weight of modified starch, 18-crown ether-6 0.0004 parts by weight, 0.0012 parts by weight of calcium oxide, 0.0012 parts by weight of sodium metaaluminate, and mix well .

Steps three to six are the same as in Example 1.

Example 3

The grade of desulfurized gypsum is 80%, and the specific surface area is 3959cm ² /g, of which the dry basis content of water-soluble magnesium oxide is 0.04%, the dry basis content of water-soluble sodium oxide is 0.13%, and the dry basis content of chloride ions is 6000mg/kg.

The specific steps for preparing gypsum board are as follows:

Step 1. Weigh 100 parts by weight of desulfurized gypsum and 0.1 parts by weight of glass fiber, mechanically stir and mix uniformly.

Step 2. Weigh 68 parts by weight of water, 0.25 parts by weight of retarder, 0.8 parts by weight of modified starch, 18-crown ether-6 0.0005 parts by weight, 0.0018 parts by weight of calcium oxide, 0.0015 parts by weight of sodium metaaluminate, and mix well .

Steps three to six are the same as in Example 1.

Example 4

The grade of desulfurized gypsum is 93% and the specific surface area is 3576cm ² /g. The dry basis content of water-soluble magnesium oxide is 0.07%, the dry basis content of water-soluble sodium oxide is 0.05%, and the dry basis content of chloride ion is 527mg/kg.

The specific steps for preparing gypsum board are as follows:

Step 1. Weigh 100 parts by weight of desulfurized gypsum and 0.12 parts by weight of glass fiber, mechanically stir and mix uniformly.

Step 2. Weigh 66 parts by weight of water, 0.9 parts by weight of retarder, 0.8 parts by weight of modified starch, 15-crown ether-5 0.0002 parts by weight, 0.0018 parts by weight of calcium oxide, 0.0015 parts by weight of sodium metaaluminate, and mix well .

Steps three to six are the same as in Example 1.

Comparative example 1

Using the desulfurized gypsum of Example 1 to prepare paper-faced gypsum board, the specific steps are as follows:

Step 2: Weigh 57 parts by weight of water, 0.8 parts by weight of retarder, and 0.3 parts by weight of modified starch, and mix them evenly.

Steps three to six are the same as in Example 1.

Comparative example 2

The desulfurized gypsum of Example 2 was used to prepare gypsum board without adding crown ether, calcium oxide, sodium metaaluminate, and the remaining components were the same as in Example 2. The steps for preparing gypsum board were also the same as in Example 2.

Comparative example 3

The desulfurized gypsum board of Example 3 was used to prepare gypsum board without adding crown ether, calcium oxide, sodium metaaluminate, and the remaining components were the same as in Example 3. The steps for preparing gypsum board were also the same as in Example 3.

Comparative example 4

The desulfurized gypsum board of Example 4 was used to prepare gypsum board without adding crown ether, calcium oxide, sodium metaaluminate, and the remaining components were the same as in Example 4. The steps for preparing gypsum board were also the same as in Example 4.

Comparative example 5

The desulfurized gypsum board in Example 1 was used to prepare gypsum board without adding crown ether, and the remaining components were the same as in Example 1. The steps for preparing gypsum board were also the same as in Example 1.

Comparative example 6

The desulfurized gypsum board in Example 1 was used to prepare gypsum board without adding calcium oxide, and the remaining components were the same as in Example 1. The steps for preparing gypsum board were also the same as in Example 1.

Comparative example 7

The paper-faced gypsum board was prepared by using the desulfurized gypsum of Example 1, without adding sodium metaaluminate, and the remaining components were the same as in Example 1, and the steps of preparing the paper-faced gypsum board were also the same as in Example 1.

Comparative example 8

Commercially available ordinary gypsum board.

Test case 1

With reference to the Chinese national standard GB/T9775-2008 "Paper-faced Gypsum Board", the gypsum boards of the above examples and comparative examples were tested to detect the physical and mechanical properties of the gypsum board. The results are shown in Table 1.

Among them, the bonding performance is divided into 5 levels. Level I: The cardboard is firmly bonded and does not separate after being lifted; Level II: A small part is separated, most of which are intact; Level III: Half is adhered and half is separated; Level IV: Most of the separation , Only a small part sticks firmly; Grade V: all the cardboard is separated.

Table 1 Performance test results of gypsum board prepared in the examples and comparative examples of the application

It can be seen from Table 1 that the paper-faced gypsum boards prepared in Examples 1 to 4 of the present application can meet the physical and mechanical properties required by the building materials industry standards in terms of performance. In Comparative Examples 1, 2, 3, and 4, crown ether, calcium oxide and sodium metaaluminate were removed on the basis of Examples 1, 2, 3, and 4. Other raw materials, raw material ratios and preparation steps were respectively the same as those of Example 1, 2, 3, 4 are the same, but the performance is lower than the requirements of Examples 1, 2, 3, 4 and the standard, especially the bonding performance is unqualified.

The mechanical properties of Comparative Examples 5, 6, and 7 without adding crown ether, or calcium oxide, or sodium metaaluminate are inferior to Example 1, and do not meet the standard requirements; compared with Comparative Example 1, the performance is similar, and none of them meets the standard Claim. It shows that the synergistic effect of crown ether, calcium oxide and sodium metaaluminate can make the performance of paper-faced gypsum board prepared from low-quality desulfurized gypsum meet national standards.

Example 5

The specific steps for preparing gypsum board are as follows:

Step 1: Weigh 100 parts by weight of desulfurized gypsum and 0.06 parts by weight of glass fiber, mechanically stir, and mix evenly.

Step 2: Weigh 0.4 parts by weight of foaming agent and 0.8 parts by weight of aldehyde agent, and stir fully.

Step 3. Weigh 57 parts by weight of water, 0.8 parts by weight of retarder, 0.3 parts by weight of modified starch, 18-crown ether-6, 0.0003 parts by weight, 0.0006 parts by weight of calcium oxide and 0.0006 parts by weight of sodium metaaluminate, and mix well .

Step 4: Inject the mixture of steps 2 and 3 into the mixture of step 2 to make a gypsum slurry.

Step 5. Throw the evenly stirred slurry onto the lower masking paper on the forming table under the action of centrifugal force. The slurry is squeezed by the forming knife under the traction of the solidification belt to make the lower masking paper roll along its roll After the traces are folded at a right angle, the lower protective paper and the slurry are lapped with the upper protective paper under the squeeze of the forming plate, and glued to form a wet plate, and then the wet plate is pulled by the solidified belt Lead out and complete the molding.

Step 6. The wet plate is solidified on the conveyor belt. After being cut, it enters the dryer and goes through three drying stages at 180°C, 110°C and 45°C.

Step 7: The dried boards are combined, sawed, sealed, and packaged to form gypsum board.

Example 6

The specific steps for preparing gypsum board are as follows:

Step 2: Weigh 1 part by weight of foaming agent and 2 parts by weight of aldehyde agent, and stir fully.

Step 3. Weigh 65 parts by weight of water, 0.5 parts by weight of retarder, 0.5 parts by weight of modified starch, 18-crown ether-6 0.0004 parts by weight, 0.0012 parts by weight of calcium oxide and 0.0012 parts by weight of sodium metaaluminate, and mix well .

Step four to step seven are the same as in Example 5.

Example 7

The specific steps for preparing gypsum board are as follows:

Step 2: Weigh 2 parts by weight of foaming agent and 4 parts by weight of aldehyde agent, and stir fully.

Step 3. Weigh 68 parts by weight of water, 0.25 parts by weight of retarder, 0.8 parts by weight of modified starch, 18-crown ether-6 0.0005 parts by weight, 0.0018 parts by weight of calcium oxide and 0.0015 parts by weight of sodium metaaluminate, and mix well .

Step four to step seven are the same as in Example 5.

Example 8

The specific steps for preparing gypsum board are as follows:

Step 2: Weigh 1.5 parts by weight of foaming agent and 5 parts by weight of aldehyde agent, and stir fully.

Step 3. Weigh 66 parts by weight of water, 0.9 parts by weight of retarder, 0.8 parts by weight of modified starch, 15-crown ether-5 0.0002 parts by weight, 0.0018 parts by weight of calcium oxide and 0.0015 parts by weight of sodium metaaluminate, and mix them evenly .

Step four to step seven are the same as in Example 5.

Comparative example 9

The desulfurized gypsum board of Example 5 was used to prepare gypsum board without adding crown ether, calcium oxide and sodium metaaluminate, and the remaining components were the same as in Example 5. The steps for preparing gypsum board were also the same as in Example 5.

Comparative example 10

The desulfurized gypsum board of Example 6 was used to prepare gypsum board without adding crown ether, calcium oxide and sodium metaaluminate, and the remaining components were the same as in Example 6, and the steps for preparing gypsum board were also the same as in Example 6.

Comparative example 11

The desulfurized gypsum of Example 7 was used to prepare gypsum board without adding crown ether, calcium oxide and sodium metaaluminate, and the remaining components were the same as in Example 7, and the steps for preparing gypsum board were also the same as in Example 7.

Comparative example 12

The desulfurized gypsum of Example 8 was used to prepare gypsum board without adding crown ether, calcium oxide and sodium metaaluminate, and the remaining components were the same as in Example 8. The steps for preparing gypsum board were also the same as in Example 8.

Comparative example 13

The desulfurized gypsum of Example 5 was used to prepare gypsum board without adding crown ether, and the remaining components were the same as in Example 5. The steps for preparing gypsum board were also the same as in Example 5.

Comparative example 14

The desulfurized gypsum board of Example 5 is used to prepare gypsum board without adding calcium oxide, and the remaining components are the same as in Example 5. The steps for preparing gypsum board are also the same as in Example 5.

Comparative example 15

The desulfurized gypsum board of Example 5 was used to prepare gypsum board without adding sodium metaaluminate, and the remaining components were the same as in Example 5. The steps for preparing gypsum board were also the same as in Example 5.

Comparative example 16

Commercially available net aldehyde gypsum board.

Test case 2

Refer to the Chinese national standard GB/T9775-2008 "Paper-faced Gypsum Board" to test the gypsum board of Example 5 to Example 8 and Comparative Example 9 to Comparative Example 16 to detect the physical and mechanical properties of the gypsum board. As shown in table 2.

Table 2 Performance test results of the gypsum boards of Examples 5 to 8 and Comparative Examples 9 to 16

It can be seen from Table 2 that the paper-faced gypsum board prepared in the examples of this application can meet the physical and mechanical properties required by the building materials industry standards in terms of performance. Comparative Examples 9, 10, 11, and 12 are based on Examples 5, 6, 7, and 8, respectively. Crown ether, calcium oxide and sodium metaaluminate are removed. Other raw materials, raw material ratios and preparation steps are respectively the same as those of Example 5. , 6, 7, and 8 are the same, but the performance is lower than that of Examples 5, 6, 7, 8 and the standard requirements, especially the bonding performance is unqualified.

The mechanical properties of Comparative Examples 13, 14, and 15 without adding crown ether, or calcium oxide, or sodium metaaluminate are worse than Example 5, which does not meet the standard requirements; compared with Comparative Example 9, the performance is similar, and none of them meets the standard. The requirements indicate that the synergistic effect of crown ether, calcium oxide and sodium metaaluminate can make the mechanical properties of paper-faced gypsum boards prepared from low-quality desulfurized gypsum meet national standards.

Test case 3

With reference to the standard JCT-1074-2008-Indoor air purification function coating material purification performance, test the purification efficiency and formaldehyde purification effect of the gypsum board of Example 1, Example 5 to Example 8, and Comparative Example 8 to Comparative Example 16. Persistence. The results are shown in Table 3.

Table 3 Test results of purification efficiency and purification durability of the gypsum boards of Example 1, Examples 5 to 8 and Comparative Examples 8 to 16

It can be seen from Table 3 that in Comparative Examples 9, 10, 11, and 12, only the crown ether, calcium oxide and sodium metaaluminate were removed from the formulations of Examples 5, 6, 7, and 8, respectively. The purification performance of formaldehyde is improved. But it is lower than Examples 5, 6, 7, and 8, indicating that low-quality desulfurized gypsum does not undergo pretreatment such as impurity ion suppression, and directly used to produce pure aldehyde gypsum board will weaken the pure aldehyde effect of aldehyde gypsum board. Analysis The reason may be that the low-quality desulfurized gypsum is not treated, which affects the internal structure of the gypsum board core, and then affects the adsorption effect of formaldehyde.

From the perspective of formaldehyde purification effect, Example 5>Comparative Example 13, Comparative Example 14, Comparative Example 15>Comparative Example 9, indicating the effect of using crown ether, calcium oxide, and sodium metaaluminate to treat low-quality desulfurized gypsum> The effect of using crown ether, calcium oxide, and sodium metaaluminate to treat low-quality desulfurized gypsum>the effect of not treating low-quality desulfurized gypsum. By comparing Example 5 with Example 1, it can be seen that by treating low-quality desulfurized gypsum and adding an aldehyde-cleaning agent, the aldehyde-cleaning effect can be better exerted.

In addition, the formaldehyde purification rate and the durability of the formaldehyde purification effect of the paper-faced gypsum board prepared by the embodiment of the present application are better than those of the commercially available pure formaldehyde gypsum board. At the same time, by comparing the single weight, breaking load, hardness and adhesion of the gypsum board of Example 1 and Example 5, Example 2 and Example 6, Example 3 and Example 7, Example 4 and Example 8. It can be seen from the performance that the addition of foaming agent and aldehyde agent has little effect on these properties of gypsum board.

The performance index testing in this application is based on national and industry standards. The paper-faced gypsum board produced by the low-quality desulfurized gypsum through the formulation and preparation process of this application meets or exceeds the requirements of national standards and has good bonding performance.

The present disclosure is an example of the principles of the embodiments of the application, and does not limit the application in any form or substance, or limit the application to specific embodiments. To those skilled in the art, it is obvious that the elements, methods, and systems of the technical solutions of the embodiments of the present application can be changed, changed, modified, and evolved without departing from the embodiments and technical solutions of the present application as described above. , As defined in the claims, the principle, spirit and scope. The implementation schemes of these changes, changes, modifications, and evolutions are all included in the equivalent embodiments of the present application, and these equivalent embodiments are all included in the scope defined by the claims of the present application. Although the embodiments of the present application can be embodied in many different forms, some embodiments of the present application are described in detail here. In addition, the examples of the present application include any possible combination of some or all of the various embodiments described herein, and are also included in the scope of the present application defined by the claims. All patents, patent applications and other cited materials mentioned in this application or anywhere in any cited patent, cited patent application or other cited materials are hereby incorporated by reference in their entirety.

The above disclosure is provided as illustrative rather than exhaustive. For those skilled in the art, this description will suggest many changes and alternatives. All these alternatives and variations are intended to be included within the scope of the claims, where the term "including" means "including, but not limited to."

This completes the description of the alternative embodiments of the application. Those skilled in the art may recognize other equivalent transformations of the embodiments described herein, and these equivalent transformations are also encompassed by the claims attached herein.

Claims

A paper-faced gypsum board, comprising: desulfurized gypsum, water, calcium oxide, metaaluminate, cyclic ether cationic complex, glass fiber, retarder and starch, wherein the metaaluminate is selected from Any one or more of alkali metal metaaluminate and alkaline earth metal metaaluminate, and the cyclic ether cation complex is selected from any one or more of crown ethers and cryptethers.
The gypsum board according to claim 1, wherein the gypsum board comprises: based on 100 parts by weight of desulfurized gypsum, 55 parts by weight to 70 parts by weight of water, 0.0005 parts by weight to 0.002 parts by weight of calcium oxide, Metaaluminate 0.0005 parts by weight to 0.002 parts by weight, cyclic ether cationic complex 0.0002 parts by weight to 0.0005 parts by weight, glass fiber 0.05 parts by weight to 0.2 parts by weight, retarder 0.2 parts by weight to 1 part by weight, starch 0.2 parts by weight to 1 part by weight.
The gypsum board according to claim 1 or 2, wherein the crown ether is selected from any one or two of 18-crown-6 and 15-crown-5, and the crypt ether is selected from Any one or two of cryptate [1,1,1], cryptate [2,2,1] and cryptate [2,2,2].
The gypsum board according to any one of claims 1 to 3, wherein the metaaluminate is selected from any one or more of sodium metaaluminate, potassium metaaluminate and magnesium metaaluminate .
The paper-faced gypsum board according to any one of claims 1 to 4, wherein the desulfurized gypsum is flue gas desulfurized gypsum with a dry basis content of chloride ions in the range of 400 mg/kg to 6000 mg/kg.
The gypsum board according to any one of claims 1 to 5, wherein the grade of the desulfurized gypsum is 80% to 100%, the dry content of water-soluble magnesium oxide is ≤0.08%, and the content of water-soluble sodium oxide is The dry basis content is ≤0.20%.
The gypsum board 1 according to claim 6, wherein said gypsum specific surface area of 3500cm 2 / g to 4000cm 2 / g.
The gypsum board according to any one of claims 1 to 7, wherein the glass fiber is selected from any one or more of medium-alkali glass fiber, alkali-free glass fiber and alkali-resistant glass fiber.
The gypsum board according to any one of claims 1 to 8, wherein the fiber length of the glass fiber is 9 mm to 15 mm, and the fiber monofilament diameter is 10 μm to 15 μm.
The gypsum board according to any one of claims 1 to 9, wherein the retarder is selected from any one of citric acid, sodium citrate, sodium hexametaphosphate, borax and protein retarders Kind or more.
The gypsum board according to claim 10, wherein the protein type retarder comprises a bone glue protein retarder and a protein type gypsum retarder formed by calcium salting of degraded polyamide.
The paper-faced gypsum board according to any one of claims 1 to 11, further comprising a foaming agent and an aldehyde agent, and based on 100 parts by weight of desulfurized gypsum, the foaming agent is 0.1 to 2 parts by weight The amount of the pure aldehyde agent is 0.5 to 5 parts by weight.
The gypsum board according to claim 12, wherein the aldehyde-cleaning agent is selected from any one or more of titanium dioxide, tetrapod zinc oxide whiskers, tin oxide and cadmium sulfide.
The method for preparing gypsum board according to any one of claims 1 to 13, comprising:

Step 1. Weigh desulfurized gypsum and glass fiber and mix them evenly;

Step 2. Optionally, mix the foaming agent and the clean aldehyde agent evenly;

Step 3: Weigh water, retarder, starch, cyclic ether cationic complex, calcium oxide, and metaaluminate, and mix them evenly to obtain a mixed solution;

Step 4. Add the mixture obtained in step one to the mixture obtained in step three, and optionally, add the mixture obtained in step two to make a gypsum slurry;

Step 5: Attach masking paper to the upper and lower surfaces of the evenly stirred gypsum slurry and shape it;

Step 6. The formed wet plate is solidified and dried after being cut;

Step 7. The dried boards are combined, sawed, sealed and packaged to form the gypsum board.
The method for preparing gypsum board according to claim 14, wherein the drying in step 6 includes three drying stages of 180°C to 155°C, 100°C to 130°C, and 45°C to 60°C.