CN111606681B - Paper-surface gypsum board and preparation method thereof - Google Patents

Abstract

The application discloses a paper-surface gypsum board and a preparation method thereof. The paper-surface gypsum board comprises: the desulfurization gypsum composition comprises, by weight, 55-70 parts of water, 0.0005-0.002 part of calcium oxide, 0.0005-0.002 part of meta-aluminate, 0.0002-0.0005 part of cyclic ether cation complex, 0.05-0.2 part of glass fiber, 0.2-1 part of retarder and 0.2-1 part of starch, wherein the meta-aluminate is selected from any one or more of alkali metal meta-aluminate and alkaline earth metal meta-aluminate, and the cyclic ether cation complex is selected from any one or more of crown ether and cryptate ether, based on 100 parts of desulfurization gypsum. The gypsum plaster board with excellent physical properties is prepared by using the low-grade desulfurized gypsum, and the utilization of the low-grade desulfurized gypsum is realized.

Description

Paper-surface gypsum board and preparation method thereof

Technical Field

The application relates to but is not limited to the field of building materials, in particular to but not limited to a paper-surface gypsum board and a preparation method thereof.

Background

The desulfurized gypsum is a product of flue gas desulfurization of a coal-fired power plant, and along with the popularization of a flue gas desulfurization project of the coal-fired power plant, the annual yield of the desulfurized gypsum in China is incredible. The desulfurized gypsum is widely used in industries such as building materials and the like, promotes the further development of national environmental protection circular economy, greatly reduces the exploitation amount of natural gypsum and protects resources.

At present, the technology for preparing the paper-surface gypsum board by utilizing the desulfurized gypsum is mature, but the quality of the paper-surface gypsum board is still influenced due to unstable gypsum quality. From chemical composition analysis, the desulfurized gypsum mainly comprises CaO and SO₃ ^2-And also includes Na₂O，K₂O，MgO，Cl^-And the like. Excessive water-soluble salt can bring quality problems of bonding, expansion, alkali resistance and the like to gypsum products, and the bonding of the protective paper of the gypsum plasterboard and the board core can be influenced by moisture absorption and crystallization of the water-soluble salt in a humid environment. Chloride ion energy and Ca²⁺And Mg²⁺A stable substance containing crystal water is formed, so that the desulfurized gypsum is not easy to dehydrate, and the calcining temperature and the calcining quality of the desulfurized gypsum are influenced; meanwhile, the high content of chloride ions can reduce the bonding performance of the protective paper and the board core in a humid environment, and the application of the gypsum board is influenced.

The raw materials of the desulfurized gypsum produced by power plants in China are generally low in quality, large in quality difference and different in product performance, so that all paper-surface gypsum board manufacturers strictly test the content of chloride ions when the desulfurized gypsum enters the factories, and the desulfurized gypsum with the content of chloride ions exceeding the standard is limited to be used.

Disclosure of Invention

The following is a summary of the subject matter described in detail herein. This summary is not intended to limit the scope of the claims.

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

The application provides a thistle board includes: the desulfurization gypsum composition comprises, by weight, 100 parts of desulfurization gypsum, 55-70 parts of water, 0.0005-0.002 part of calcium oxide, 0.0005-0.002 part of meta-aluminate, 0.0002-0.0005 part of cyclic ether cation complex, 0.05-0.2 part of glass fiber, 0.2-1 part of retarder and 0.2-1 part of starch, wherein the meta-aluminate is selected from any one or more of alkali metal meta-aluminate and alkaline earth metal meta-aluminate, and the cyclic ether cation complex is selected from any one or more of crown ether and cryptate ether.

In the embodiment of the application, the desulfurized gypsum can be flue gas desulfurized gypsum with the dry content of chloride ions in the range of 400mg/kg to 6000mg/kg (according to the national construction materials industry standard JC/T2074-2011 flue gas desulfurized gypsum, the technical requirement of the third-level desulfurized gypsum provides that the dry content of chloride ions is less than or equal to 400 mg/kg).

In the embodiment of the application, the grade of the desulfurized gypsum (i.e. the mass percentage of the calcium sulfate dihydrate in the dry desulfurized gypsum) can be 80-100%, the dry content of the water-soluble magnesium oxide can be less than or equal to 0.08%, and the dry content of the water-soluble sodium oxide can be less than or equal to 0.20% (according to the technical requirements of JC/T2074 plus 2011 flue desulfurized gypsum, the technical requirements of the third-level desulfurized gypsum that the dry content of the calcium sulfate dihydrate is more than or equal to 85%, the dry content of the water-soluble magnesium oxide is less than or equal to 0.08%, and the dry content of the water-soluble sodium oxide is less than or equal to 0.20%). The grade of the desulfurized gypsum in a common factory is limited to more than 90 percent, and the content of chloride ions is limited to 300 ppm. In the application, the grade of the desulfurized gypsum, the dry content of the water-soluble magnesium oxide and the dry content of the water-soluble sodium oxide are all expressed by mass fraction by the same expression method as JC/T2074-.

In the examples of the present application, the specific surface area of the desulfurized gypsum may be 3500cm²G to 4000cm²/g。

In the examples herein, the crown ether may be selected from any one or both of 18-crown-6 and 15-crown-5.

In embodiments herein, the cryptate may be selected from any one or more of cryptate [1,1,1], cryptate [2,2,1] and cryptate [2,2,2 ].

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

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

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

In 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-based retarders.

In an embodiment of the present application, the protein-based retarder may include a bone glue protein retarder and a protein-based gypsum retarder in which degraded polyamide is calcium-salted.

The application also provides a preparation method of the paper-surface gypsum board, which comprises the following steps:

weighing desulfurized gypsum and glass fiber, and uniformly mixing;

weighing water, a retarder, starch, a cyclic ether cationic complex, calcium oxide and metaaluminate, and uniformly mixing to obtain a mixed solution;

step three, adding the mixture obtained in the step one into the mixed liquid obtained in the step two to prepare gypsum slurry;

step four, attaching protective paper to the upper surface and the lower surface of the gypsum slurry which is uniformly stirred and forming;

step five, solidifying the formed wet plate, cutting off the wet plate, and drying the wet plate;

and step six, combining the dried boards, sawing edges, sealing edges and packaging to form the gypsum plaster board.

In an embodiment of the present application, the step four may include: and throwing the gypsum slurry which is uniformly stirred onto the protective paper under the action of centrifugal force, extruding by a forming cutter, folding the protective paper into a right angle, overlapping with another protective paper under the extrusion of a forming plate, firmly bonding to form a wet plate, and then leading out the wet plate to finish forming.

In the embodiment of this application, can get rid of the even ground paste of stirring under the centrifugal force effect on getting rid of the lower mask paper on the shaping bench, the ground paste is through the extrusion of shaping sword under the drive of solidification belt traction force, make under mask paper along its roller go out trace department fold into the right angle after, lower mask paper and ground paste together under the extrusion of shaping board with last mask paper overlap joint to glue firmly and form wet board, wet board is drawn forth under the traction of solidification belt afterwards, accomplishes the shaping.

In an embodiment of the present application, the drying of step five may include: three drying stages of 180-155 deg.c, 100-130 deg.c and 45-60 deg.c.

The paper-faced gypsum board can be prepared from low-quality desulfurized gypsum with high water-soluble salt content. Crown ether or crypt ether hole molecular structure complexing alkali metal ions; calcium oxide, sodium metaaluminate and water-soluble chloride ions in gypsum slurry react to generate calcium-aluminum-chloride layered compound Ca with extremely low solubility₄Al₂Cl₂(OH)₁₂Thereby removing magnesium oxide, sodium oxide and chloride ions.

The paper-surface gypsum board prepared by the method reaches the national standard in terms of single weight, longitudinal fracture load, transverse fracture load, stripping of the protective paper and the core material, edge hardness, end hardness and bonding performance, and is even superior to common paper-surface gypsum boards on the market, so that the utilization of low-quality desulfurized gypsum is realized.

Additional features and advantages of the application will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by the practice of the application. The objectives and other advantages of the application may be realized and attained by the structure particularly pointed out in the written description and claims hereof.

Detailed Description

Hereinafter, embodiments of the present application will be described in detail to make objects, technical solutions and advantages of the present application more apparent. It should be noted that the embodiments and features of the embodiments in the present application may be arbitrarily combined with each other without conflict.

In the following examples, the desulfurized gypsum clinker used is made of desulfurized gypsum from solid waste produced by flue gas desulfurization in power plants; the glass fiber is purchased from mineral products limited of Jinghang of Hebei Jing, is alkali-free glass fiber, and has the fiber length of 10mm and the fiber monofilament diameter of 10 mu m; crown ether, calcium oxide, sodium metaaluminate were purchased from chemical agents of national drug group, ltd; the modified starch is purchased from Jinan Yuan chemical Co., Ltd; the retarder is protein gypsum retarder formed by calcium calcification of degraded polyamide, Italy SISISIIT 2000 gypsum retarder plat Retard PE, purchased from Shanghai Qinzhi and chemical engineering Co.

Example 1

The grade of the desulfurized gypsum is 84 percent, and the specific surface area is 3587cm²The water-soluble magnesium oxide, the water-soluble sodium oxide and the chloride ions are mixed together, wherein the dry content of the water-soluble magnesium oxide is 0.08 percent, the dry content of the water-soluble sodium oxide is 0.19 percent and the dry content of the chloride ions is 1000 mg/kg.

The method for preparing the paper-surface gypsum board comprises the following specific steps:

step one, weighing 100 parts by weight of desulfurized gypsum and 0.06 part by weight of glass fiber, mechanically stirring and uniformly mixing.

Step two, weighing 57 parts by weight of water, 0.8 part by weight of retarder, 0.3 part by weight of modified starch, 18-crown-60.0003 parts by weight, 0.0006 part by weight of calcium oxide and 0.0006 part by weight of sodium metaaluminate, and uniformly mixing.

And step three, adding the mixture of the desulfurized gypsum and the glass fiber obtained in the step one into the mixed solution obtained in the step two to prepare gypsum slurry.

And step four, throwing the uniformly stirred slurry onto the lower protective paper on the forming table under the action of centrifugal force, extruding the slurry by a forming cutter under the driving of the traction force of a solidification belt, folding the lower protective paper into a right angle along the roller mark, overlapping the lower protective paper and the slurry with the upper protective paper under the extrusion of a forming plate, firmly bonding to form a wet plate, and then leading out the wet plate under the traction of the solidification belt to finish forming.

And step five, solidifying the wet plate on a conveying belt, cutting the wet plate, and then entering a dryer to be dried at the temperature of 180 ℃, 110 ℃ and 45 ℃.

Step six: and (4) combining the dried boards, sawing edges, sealing edges and packaging to form the gypsum plaster board.

Example 2

The grade of the desulfurized gypsum is 82 percent, and the specific surface area is 3873cm²The water-soluble magnesium oxide powder contains 0.06 percent of water-soluble magnesium oxide on a dry basis, 0.12 percent of water-soluble sodium oxide on a dry basis and 3000mg/kg of chloride ions on a dry basis.

The method for preparing the paper-surface gypsum board comprises the following specific steps:

step one, weighing 100 parts by weight of desulfurized gypsum and 0.18 part by weight of glass fiber, mechanically stirring and uniformly mixing.

Step two, weighing 65 parts by weight of water, 0.5 part by weight of retarder, 0.5 part by weight of modified starch, 18-crown-60.0004 parts by weight, 0.0012 part by weight of calcium oxide and 0.0012 part by weight of sodium metaaluminate, and uniformly mixing.

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

Example 3

The grade of the desulfurized gypsum is 80 percent, and the specific surface area is 3959cm²Per g, wherein the water-soluble magnesium oxide has a dry content of 0.04%, and the water-soluble sodium oxide has a dry contentThe content is 0.13 percent, and the dry basis content of the chloride ions is 6000 mg/kg.

The method for preparing the paper-surface gypsum board comprises the following specific steps:

step one, weighing 100 parts by weight of desulfurized gypsum and 0.1 part by weight of glass fiber, mechanically stirring and uniformly mixing.

Step two, weighing 68 parts of water, 0.25 part of retarder, 0.8 part of modified starch, 18-crown-60.0005 parts, 0.0018 part of calcium oxide and 0.0015 part of sodium metaaluminate, and uniformly mixing.

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

Example 4

The grade of the desulfurized gypsum is 93 percent, and the specific surface area is 3576cm²The water-soluble magnesium oxide powder contains 0.07 percent of water-soluble magnesium oxide on a dry basis, 0.05 percent of water-soluble sodium oxide on a dry basis and 527mg/kg of chloride ions on a dry basis.

The method for preparing the paper-surface gypsum board comprises the following specific steps:

step one, weighing 100 parts by weight of desulfurized gypsum and 0.12 part by weight of glass fiber, mechanically stirring and uniformly mixing.

Step two, weighing 66 parts of water, 0.9 part of retarder, 0.8 part of modified starch, 15-crown-50.0002 parts of calcium oxide, 0.0018 part of calcium oxide and 0.0015 part of sodium metaaluminate, and uniformly mixing.

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

Comparative example 1

The gypsum plasterboard prepared from the desulfurized gypsum of example 1 comprises the following specific steps:

step one, weighing 100 parts by weight of desulfurized gypsum and 0.06 part by weight of glass fiber, mechanically stirring and uniformly mixing.

And step two, weighing 57 parts by weight of water, 0.8 part by weight of retarder and 0.3 part by weight of modified starch, and uniformly mixing.

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

Comparative example 2

The gypsum plasterboard prepared from the desulfurized gypsum of example 2 was prepared by the same procedure as in example 2 except that crown ether, calcium oxide and sodium metaaluminate were not added, and the remaining components were the same as in example 2.

Comparative example 3

The gypsum plasterboard prepared from the desulfurized gypsum of example 3 was prepared without adding crown ether, calcium oxide and sodium metaaluminate, and the remaining components were the same as in example 3, and the procedure for preparing the gypsum plasterboard was the same as in example 3.

Comparative example 4

The gypsum plasterboard prepared from the desulfurized gypsum of example 4 was prepared without adding crown ether, calcium oxide and sodium metaaluminate, and the remaining components were the same as in example 4, and the procedure for preparing the gypsum plasterboard was the same as in example 4.

Comparative example 5

A gypsum plasterboard was produced by using the desulfurized gypsum of example 1, and the procedure for producing the gypsum plasterboard was the same as in example 1 except that crown ether was not added.

Comparative example 6

A gypsum plasterboard was produced by using the desulfurized gypsum of example 1, and the procedure for producing the gypsum plasterboard was the same as in example 1 except that calcium oxide was not added.

Comparative example 7

A gypsum plasterboard was prepared from the desulfurized gypsum of example 1, the remaining components were the same as in example 1 without adding sodium metaaluminate, and the procedure for producing the gypsum plasterboard was the same as in example 1.

Comparative example 8

Common paper-faced gypsum board is commercially available.

Test example 1

The gypsum plasterboards of examples and comparative examples were tested with reference to the chinese national standard GB/T9775-2008 "gypsum plasterboard", and the physical and mechanical properties of the gypsum plasterboards were measured, with the results shown in table 1.

Wherein, the adhesive property is divided into 5 grades, I grade: the paper boards are firmly bonded and are not separated after being lifted; II stage: a small part is separated, and a large part is intact; grade III: half of the adhesive is firmly adhered, and the other half of the adhesive is separated; stage IV: most of the materials are separated, and only a small part of the materials are firmly adhered; and V stage: the cardboard is totally separated.

TABLE 1 paper-faced gypsum board performance test results prepared in the examples and comparative examples of the present application

As can be seen from Table 1, the gypsum plasterboard prepared in the embodiment of the present application can meet the physical and mechanical properties required by the building material industry standard in terms of performance. Comparative examples 1, 2, 3 and 4 crown ether, calcium oxide and sodium metaaluminate were removed from examples 1, 2, 3 and 4, and other raw materials, raw material ratios and preparation steps were the same as those of examples 1, 2, 3 and 4, respectively, but the performances were lower than those of examples 1, 2, 3 and 4 and the standard requirements, and in particular, the adhesive properties were not satisfactory.

The mechanical properties of comparative examples 5, 6 and 7 without crown ether, calcium oxide or sodium metaaluminate are worse than that of example 1 and do not meet the standard requirements; compared with comparative example 1, the performance is similar, and the standard requirements are not met. The synergistic effect of crown ether, calcium oxide and sodium metaaluminate is proved to enable the performance of the gypsum plaster board prepared from the low-quality desulfurized gypsum to reach the national standard.

The performance index detection in the present application is based on national and industry standards. The paper-surface gypsum board produced by the low-quality desulfurized gypsum through the formula and the preparation process meets or is higher than the requirements of national standards, and has good bonding property.

Although the embodiments disclosed in the present application are described above, the descriptions are only for the convenience of understanding the present application, and are not intended to limit the present application. It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the disclosure as defined by the appended claims.

Claims (11)

1. A paper-faced gypsum board comprising: based on 100 parts by weight of desulfurized gypsum, 55 to 70 parts by weight of water, 0.0005 to 0.002 part by weight of calcium oxide, 0.0005 to 0.002 part by weight of meta-aluminate, 0.0002 to 0.0005 part by weight of cyclic ether cation complex, 0.05 to 0.2 part by weight of glass fiber, 0.2 to 1 part by weight of retarder and 0.2 to 1 part by weight of starch, wherein the grade of the desulfurized gypsum is 80 to 100 percent, the dry content of chloride ions in the desulfurized gypsum is within the range of 400 to 6000mg/kg, the dry content of water-soluble magnesium oxide is less than or equal to 0.08 percent, and the dry content of water-soluble sodium oxide is less than or equal to 0.20 percent; the meta-aluminate is selected from one or more of meta-aluminate of alkali metal and meta-aluminate of alkaline earth metal, and the cyclic ether cation complex is selected from one or more of crown ether and cryptate ether.

2. The paper-faced gypsum board of claim 1, 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 crypt ether [1,1,1], crypt ether [2,2,1] and crypt ether [2,2,2 ].

3. The gypsum plasterboard of claim 1, wherein the meta-aluminate is selected from any one or more of sodium meta-aluminate, potassium meta-aluminate and magnesium meta-aluminate.

4. The gypsum plasterboard of claim 1, wherein the desulphurised gypsum is flue gas desulphurised gypsum.

5. The gypsum plasterboard of claim 1 or 4, wherein the specific surface area of the desulphurized gypsum is 3500cm²G to 4000cm²/g。

6. The gypsum plasterboard of claim 1, wherein the glass fibres are selected from any one or more of medium alkali glass fibres, alkali-free glass fibres and alkali-resistant glass fibres.

7. The gypsum plasterboard of claim 1 or 6, wherein the glass fibres have a fibre length of 9 to 15mm and a fibre filament diameter of 10 to 15 μm.

8. The paper-faced gypsum board of claim 1, wherein the set retarder is selected from any one or more of citric acid, sodium citrate, sodium hexametaphosphate, borax, and protein-based set retarders.

9. The gypsum plasterboard of claim 8, wherein the protein-based retarder is selected from any one or more of a bone collagen protein retarder and a protein-based gypsum retarder in which degraded polyamide is calcium-salted.

10. A method of making the paper-faced gypsum board of any one of claims 1 to 9, the method of making comprising:

weighing desulfurized gypsum and glass fiber, and uniformly mixing;

weighing water, a retarder, starch, a cyclic ether cationic complex, calcium oxide and metaaluminate, and uniformly mixing to obtain a mixed solution;

step three, adding the mixture obtained in the step one into the mixed liquid obtained in the step two to prepare gypsum slurry;

step four, attaching protective paper to the upper surface and the lower surface of the gypsum slurry which is uniformly stirred and forming;

step five, solidifying the formed wet plate, cutting off the wet plate, and drying the wet plate;

and step six, combining the dried boards, sawing edges, sealing edges and packaging to form the gypsum plaster board.

11. The method of claim 10, wherein the drying of step five comprises three drying stages of 180 ℃ to 155 ℃, 100 ℃ to 130 ℃, 45 ℃ to 60 ℃.