Gypsum plaster board, preparation method thereof and treatment method of low-quality gypsum

Abstract

The invention relates to a gypsum plaster board, a preparation method thereof and a treatment method of low-quality gypsum, the gypsum plaster board comprises a board core and surface protection paper, and the board core comprises the following raw materials: gypsum raw material, zeolite, metakaolin and cement. The gypsum plaster board has the properties of high strength, heat preservation, heat insulation, light weight and the like.

Description

Technical Field

[0001] The present invention relates to but is not limited to building material technology, and in particular to but is not limited to a gypsum board and a preparation method thereof. The gypsum board is specifically a functional (high-strength, heat-insulating, thermally insulating, and lightweight) paper-faced gypsum board. Background Art

[0002] As we all know, gypsum board is a building decoration material with good performance. With the reduction of natural gypsum storage, industrial by-product gypsum (especially desulfurized gypsum) gradually replaces natural gypsum as the main raw material for preparing gypsum board. Due to the uneven desulfurization technology and process level of domestic power plants, desulfurized gypsum contains a certain amount of soluble impurities (such as sodium ions, magnesium ions and chloride ions). Desulfurized gypsum with high impurity ion content has an adverse effect on the performance of gypsum products. For example, gypsum board prepared with desulfurized gypsum with high impurity ion content is prone to problems such as separation of the board core and the paper core and surface frost. In recent years, many domestic scientific research units have successively carried out research on the treatment and purification of industrial by-product gypsum (desulfurized gypsum, phosphogypsum, fluorinated gypsum, etc.) and the preparation of gypsum-based products. However, there are few reports on the use of low-quality desulfurized gypsum with high impurity ion content to prepare functional boards with excellent performance.

[0003] Therefore, using low-quality desulfurized gypsum with high impurity ion content to prepare new functional boards is a new way to realize the resource utilization of industrial by-product gypsum. Summary of the invention

[0004] The following is an overview of the subject matter described in detail herein. This overview is not intended to limit the scope of protection of this application.

[0005] The present application provides a gypsum-based paper-faced gypsum board prepared by using low-quality desulfurized gypsum, wherein the paper-faced gypsum board has the properties of high strength, heat preservation, thermal insulation, light weight, etc.

[0006] The first aspect of the present application provides a paper-faced gypsum board, which includes a board core and a facing paper, and the raw materials of the board core include: gypsum raw material, zeolite, metakaolin and cement.

[0007] In an exemplary embodiment, the weight ratio of the gypsum raw material, zeolite, metakaolin and cement is 100:(0.1 to 5):(0.1-5):(0.2-10).

[0008] In an exemplary embodiment, the particle size of the gypsum raw material is 80 mesh to 100 mesh. When the particle size of the gypsum raw material is within this range, a gypsum-based board with better performance can be obtained.

[0009] In an exemplary embodiment, the particle size of the zeolite is 200 mesh to 1500 mesh.

[0010] In an exemplary embodiment, the cement may be selected from aluminate cement, sulphoaluminate cement, silicate cement or other types of cement; preferably, the cement is silicate cement.

[0011] In an exemplary embodiment, the thickness of the gypsum board is 9.5 mm to 12 mm.

[0012] In an exemplary embodiment, the raw materials of the board core further include polyvinyl alcohol, starch, a water reducing agent and a foaming agent.

[0013] In an exemplary embodiment, the weight ratio of the gypsum raw material, the polyvinyl alcohol, the starch, the water reducing agent and the foaming agent is 100:(0 to 3):(0 to 1):(0 to 0.3):(0 to 0.05);

[0014] Preferably, the weight ratio of the gypsum raw material, the polyvinyl alcohol, the starch, the water reducing agent and the foaming agent is 100:(0.3 to 3):(0.3 to 1):(0.04 to 0.3):(0.01 to 0.05).

[0015] In an exemplary embodiment, the gypsum raw material is low-quality gypsum; specifically, the gypsum raw material is low-quality desulfurization gypsum, and the low-quality gypsum raw material here does not meet the impurity ion content specified in the technical requirements for tertiary desulfurization gypsum in the JC / T 2074-2011 "Flue Gas Desulfurization Gypsum" standard.

[0016] In an exemplary embodiment, the Cl in the low-quality gypsum - The content is between 0.03wt.% and 0.9wt.%, Mg 2+ Ion content is not higher than 1000ppmw, Na + The ion content is not higher than 700ppmw.

[0017] In an exemplary embodiment, the starch is modified starch; optionally, the starch has a gelatinization temperature of 60-75° C. and a viscosity of 5-20 mPa.s.

[0018] In an exemplary embodiment, the water reducer is selected from one or more of a polycarboxylic acid-based water reducer and a melamine-based sulfonated polycondensate water reducer.

[0019] In an exemplary embodiment, the polyvinyl alcohol is selected from any one or more of polyvinyl alcohol PVA2488 and polyvinyl alcohol PVA1788.

[0020] In an exemplary embodiment, the foaming agent is an anionic surfactant; optionally, the anionic surfactant is selected from sodium dodecylbenzene sulfonate (such as K12), sodium dodecyl sulfate, BASF One or more of SASN 812, 3110.

[0021] The second aspect of the present application provides a method for preparing the above-mentioned gypsum board, comprising the following steps:

[0022] 1) mixing gypsum raw material, zeolite and metakaolin uniformly and calcining the mixture to obtain a mixture 1;

[0023] 2) mixing silicate cement and the mixture 1 uniformly to obtain a premixed powder;

[0024] 3) uniformly mixing the premixed powder with polyvinyl alcohol, starch and a water reducing agent to obtain a mixed powder and testing the standard consistency spread thereof to obtain a standard consistency water consumption of the mixed powder;

[0025] 4) determining mixing water according to the standard consistency water amount in step 3), and uniformly mixing the mixing water and the foaming agent, and then uniformly mixing the mixing water with the mixed powder to obtain gypsum slurry;

[0026] 5) overlapping and bonding the gypsum slurry with the upper and lower facing papers to form a wet gypsum board;

[0027] 6) Drying the wet gypsum board to obtain the gypsum board.

[0028] In an exemplary embodiment, in step 6), the drying comprises the following steps:

[0029] The wet gypsum board is cured at room temperature and relative humidity of 50-90% for 1-3 days; and dried at 80-120° C. for 30-90 minutes;

[0030] Dry at 40-50℃ until the board is completely dry to obtain paper-faced gypsum board.

[0031] The third aspect of the present application provides a method for processing low-quality gypsum, comprising the following steps: mixing the low-quality gypsum with zeolite, metakaolin and cement, calcining, aging, cooling and setting aside.

[0032] In an exemplary embodiment, the low-quality gypsum is low-quality desulfurization gypsum, and the low-quality gypsum here does not meet the impurity ion content specified in the technical requirements for tertiary desulfurization gypsum in the JC / T 2074-2011 "Flue Gas Desulfurization Gypsum" standard.

[0033] In an exemplary embodiment, the Cl in the low-quality gypsum- The content is between 0.03wt.% and 0.9wt.%, Mg 2+ Ion content is not higher than 1000ppmw, Na + The ion content is not higher than 700ppmw.

[0034] In an exemplary embodiment, the cement may be selected from aluminate cement, sulphoaluminate cement, silicate cement or other types of cement; preferably, the cement is silicate cement.

[0035] The technical solution of this application has the following advantages:

[0036] 1. Gypsum board uses low-quality desulfurized gypsum with high impurity content as its main raw material. Low-quality desulfurized gypsum contains a large amount of Mg 2+ , Cl - By treating low-quality desulfurized gypsum, the Mg 2+ , Cl - The impurity ions solidify and the morphology of the desulfurized gypsum changes, thus realizing the resource utilization of low-quality desulfurized gypsum and also making it have good performance, thereby obtaining a decorative functional paper-faced gypsum board.

[0037] 2. The obtained gypsum board has good board strength and light weight.

[0038] 3. Can solidify impurity ions.

[0039] 4. The obtained paper-faced gypsum board has good thermal insulation performance and can effectively reduce the energy consumption of building envelope structures; at the same time, it has good sound insulation performance.

[0040] 5. The obtained paper-faced gypsum board has a temperature regulating function, which can effectively reduce the fluctuation range of indoor temperature and improve living comfort.

[0041] 6. The various raw material components of the obtained gypsum board have good compatibility and are easy to adjust and control.

[0042] Other features and advantages of the present application will be described in the following description, and partly become apparent from the description, or be understood by implementing the present application. Other advantages of the present application can be invented and obtained by the schemes described in the description. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] The accompanying drawings are used to provide an understanding of the technical solution of the present application and constitute a part of the specification. Together with the embodiments of the present application, they are used to explain the technical solution of the present application and do not constitute a limitation on the technical solution of the present application.

[0044] Figure 1This is the SEM morphology of the low-quality desulfurized gypsum after treatment in Example 1. Through SEM scanning, it can be seen that compared with the granular low-quality desulfurized gypsum before treatment, there are many long columns or rod-shaped crystals in the desulfurized gypsum after treatment. Such morphological features have positive significance for the strength of gypsum products or gypsum boards. DETAILED DESCRIPTION

[0045] In order to make the purpose, technical solution and advantages of the present application more clear, the embodiments of the present application are described in detail below. It should be noted that the embodiments and features in the embodiments of the present application can be combined with each other arbitrarily without conflict.

[0046] In the examples and comparative examples of the present application:

[0047] The low-quality desulfurization gypsum raw material comes from a power plant in Ninghai;

[0048] Zeolite was purchased from Guotou Shengshi Technology Co., Ltd.;

[0049] The cement was commercially available Zuan brand 425# silicate cement;

[0050] Metakaolin was from Shanxi Chaopai Calcined Kaolin Co., Ltd., model K1100;

[0051] Polyvinyl alcohol was polyvinyl alcohol PVA2488, purchased from Kuraray Co., Ltd., Japan;

[0052] Starch was purchased from a company in Zhuozhou. The gelatinization temperature of starch was 75°C and the viscosity was 8.5mpa.s.

[0053] The water reducer is a polycarboxylate water reducer purchased from BASF. 5691F brand;

[0054] The foaming agent is sodium dodecylbenzene sulfonate, purchased from Shandong Jujin Chemical Materials Co., Ltd., brand K12.

[0055] In the following specific examples, the operations involved, if the conditions are not specified, are all carried out under conventional conditions or conditions recommended by the manufacturer. The raw materials used, if the manufacturers and specifications are not specified, are all conventional products that can be obtained from the market.

[0056] Example 1

[0057] (1) Select 1kg (Mg) of gypsum raw material 2+ Content 500ppmw, Na + Content 600ppmw, Cl - Content 0.1wt.%) ball mill for 5min until the particle size passes through 80 mesh sieve, zeolite 325 mesh 40g, metakaolin 30g, mix well, calcine at 150℃ for 2h, age, cool and set aside;

[0058] (2) Weigh 50 g of Portland cement;

[0059] (3) mixing the powders obtained in step (1) and step (2) to prepare a premixed powder for later use;

[0060] (4) The premixed powder obtained in step (3) is mixed with 5 g of polyvinyl alcohol, 5 g of starch, and 0.5 g of a water reducing agent to obtain a mixed powder and its standard consistency water consumption is tested. The mixing water is determined according to the standard consistency water consumption; 0.2 g of a foaming agent is added to the mixing water and stirred evenly;

[0061] (5) The mixed powder and mixing water are mixed evenly to prepare gypsum slurry, and the prepared gypsum slurry is overlapped and bonded with the upper and lower facing papers to form a gypsum board; the gypsum board is placed in a 25° C., 90% RH humidity environment for 24 hours, and then placed in an oven and dried at a temperature of 80° C. for 120 minutes; the temperature is lowered to 45° C. and the drying is continued until the board is completely dry.

[0062] Example 2

[0063] The difference between this embodiment and embodiment 1 is only step (2):

[0064] (2) Weigh 70 g of Portland cement.

[0065] Example 3

[0066] The difference between this embodiment and embodiment 1 is only step (2):

[0067] (2) Weigh 20 g of Portland cement.

[0068] Example 4

[0069] The difference between this embodiment and embodiment 1 is only step (1):

[0070] (1) Select 1kg (Mg) of gypsum raw material 2+ Content 500ppmw, Na + Content 600ppmw, Cl - Content 1000ppmw), ball mill for 5min until the particle size passes through 80 mesh sieve, 4g zeolite 325 mesh, 10g metakaolin, mix evenly, calcine at 150℃ for 2h, age, cool and set aside.

[0071] Example 5

[0072] (1) Select 1kg (Mg) of gypsum raw material 2+ Content 400ppmw, Na + Content 600ppmw, Cl -Content 0.05wt.%) ball mill for 5min until the particle size passes through 80 mesh sieve, zeolite 325 mesh 2g, metakaolin 6g, mix well, calcine at 150℃ for 2h, age, cool and set aside.

[0073] (2) Weigh 10 g of Portland cement,

[0074] (3) mixing the powders obtained in step (1) and step (2) to prepare a premixed powder for later use;

[0075] (4) The premixed powder obtained in step (3) is mixed with 3 g of polyvinyl alcohol, 5 g of starch, and 0.5 g of a water reducing agent to obtain a mixed powder and its standard consistency water consumption is tested; the mixing water is determined according to the standard consistency water consumption, 0.2 g of a foaming agent is added to the mixing water, and the mixture is stirred evenly;

[0076] (5) Mix the mixed powder and mixing water evenly to prepare a slurry, and overlap and bond the prepared slurry with the upper and lower face papers to form a gypsum board; place the gypsum board in a 25° C., 90% RH humidity environment for 24 hours, then place it in an oven and dry it at 80° C. for 120 minutes; reduce the temperature to 45° C. and continue drying until the board is completely dry.

[0077] Comparative Example 1

[0078] The raw materials and preparation method are the same as those in Example 1, except that there is no step (2).

[0079] Comparative Example 2

[0080] The raw materials and preparation method are the same as those in Example 1, except that there is no step (2) and no zeolite is added in step (1).

[0081] Comparative Example 3

[0082] The raw materials and preparation method are the same as those in Example 5, except that there is no step (2).

[0083] Comparative Example 4

[0084] The raw materials and preparation method are the same as those in Example 5, except that there is no step (2) and no zeolite is added in step (1).

[0085] Comparative Example 5

[0086] (1) Select 1kg (Mg) of gypsum raw material 2+ Content 400ppmw, Na + Content 600ppmw, Cl - Content 500ppmw), calcined at 150℃ for 2h, aged, cooled and used;

[0087] (2) testing the standard consistency water consumption, and determining the mixing water according to the standard consistency water consumption; uniformly mixing the gypsum raw material and mixing water of step (1) to prepare a slurry, and overlapping and bonding the prepared slurry with the upper and lower face papers to form a gypsum board; placing the paper-faced gypsum board in an environment of 25° C. and 90% RH for 24 hours, and then placing it in an oven and drying it at a temperature of 80° C. for 120 minutes; lowering the temperature to 45° C. and continuing to dry until the board is completely dry.

[0088] Performance Testing

[0089] 1. Mechanical properties test: According to the Chinese national standard GB / T17669.3-1999 standard method, the slurries prepared in the examples and comparative examples were made into 40 mm*40 mm*160 mm test blocks, and their mechanical properties were tested. The results are shown in Table 1.

[0090] Table 1 Mechanical properties test of test blocks prepared by slurry in the examples and comparative examples

[0091]

[0092] 2. Board breaking load test: The breaking loads of the gypsum boards prepared in the examples and comparative examples were tested according to the standard method of Chinese national standard GB / T9775-2008. The results are shown in Table 2.

[0093] Table 2 Mechanical properties test of gypsum board prepared by slurry in the examples and comparative examples

[0094]

[0095]

[0096] 3. Frosting

[0097] After the board was placed at room temperature for 180 days, the surface paper was peeled off and its surface was observed. It was found that there was no frosting on the surface of Examples 1-5, but there was frosting on the surface of Comparative Examples 2, 4 and 5, and there was slight frosting on the surface of Comparative Examples 1 and 3.

[0098] 4. Fire resistance stability test: The fire stability of the gypsum boards prepared in the examples and comparative examples was tested according to the method of Chinese national standard GB / T9775-2008 "Gypsum Board". The results are shown in Table 3.

[0099] Table 3 Fire stability of gypsum boards prepared in the examples and comparative examples

[0100] Fire stability / min Example 1 350 Example 2 260 Example 3 200 Example 4 120 Example 5 89 Comparative Example 1 59 Comparative Example 2 45 Comparative Example 3 40 Comparative Example 4 42 Comparative Example 5 35

[0101] 5. Adhesion performance test:

[0102] 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, and most of it is intact; Level III: half is firmly bonded and half is separated; Level IV: most of it is separated, and only a small part is firmly bonded; Level V: the cardboard is completely separated.

[0103] The gypsum boards of the embodiments and comparative examples were tested with reference to the Chinese national standard GB / T9775-2008 "Gypsum Board" to detect the dry bonding performance of the gypsum boards.

[0104] The wet heat bonding performance test method is as follows: the prepared gypsum board is placed in a 100°C water bath for hot steam curing for 12 minutes, and the bonding performance of the gypsum board is tested by drawing an equilateral triangle, and the test is completed within 1 minute.

[0105] High humidity environment test: The prepared gypsum board is cured under high humidity conditions (temperature is (23±2)℃, relative humidity is 90±3). After reaching the specified age for one week, the bonding performance of the gypsum board is tested by drawing an equilateral triangle.

[0106] Table 4 Comparison of bonding properties

[0107]

[0108] 6. After the test blocks are prepared from the slurry, they are placed at room temperature for 1 year, placed in an oven (45°C) and dried to constant weight, and then the mechanical properties are tested: According to the standard method of the Chinese national standard GB / T17669.3-1999, the slurry used to prepare the gypsum board in the test examples and comparative examples was made into 40mm*40mm*160mm test blocks, and their mechanical properties were tested. The results are shown in Table 5.

[0109] Table 5 Mechanical properties test of test blocks prepared by slurry in the examples and comparative examples

[0110]

[0111]

[0112] It can be seen from this that the mechanical properties of the paper-faced gypsum board provided in the present application are significantly improved, the bonding performance of the board is good, and the mechanics of the board is significantly improved after being placed for a long time.

[0113] Although the embodiments disclosed in this application are as above, the contents described are only embodiments adopted to facilitate understanding of this application and are not intended to limit this application. Any technician in the field to which this application belongs can make any modifications and changes in the form and details of implementation without departing from the spirit and scope disclosed in this application, but the scope of patent protection of this application shall still be based on the scope defined in the attached claims.

Claims

1. A paper-faced gypsum board, the gypsum board comprising a board core and a facing paper, the raw materials of the board core comprising: Gypsum raw material, zeolite, metakaolin and cement; The weight ratio of the gypsum raw material, zeolite, metakaolin and cement is 100:(0.1 to 5):(0.1-5):(0.2-10).

2. The gypsum board according to claim 1, wherein: The raw materials of the board core also include polyvinyl alcohol, starch, water reducing agent and foaming agent; Optionally, the weight ratio of the gypsum raw material, the polyvinyl alcohol, the starch, the water reducing agent and the foaming agent is 100:(0 to 3):(0 to 1):(0 to 0.3):(0 to 0.05); Preferably, the weight ratio of the gypsum raw material, the polyvinyl alcohol, the starch, the water reducing agent and the foaming agent is 100:(0.3 to 3):(0.3 to 1):(0.04 to 0.3):(0.01 to 0.05).

3. The gypsum board according to claim 1 or 2, wherein: The gypsum raw material is low-quality desulfurized gypsum; Optionally, Cl in the gypsum raw material - The content is between 0.03wt.% and 0.9wt.%, Mg 2+ Ion content is not higher than 1000ppmw, Na + Ion content is not higher than 700ppmw; Optionally, the particle size of the gypsum raw material is 80 mesh to 100 mesh.

4. The gypsum board according to claim 1 or 2, wherein: The particle size of the zeolite is 200 mesh to 1500 mesh; and / or The cement may be selected from aluminate cement, sulphoaluminate cement, silicate cement or other types of cement; preferably, the cement is silicate cement.

5. The gypsum board according to claim 2, wherein: The starch is modified starch; Optionally, the gelatinization temperature of the starch is 60-75°C; Optionally, the starch viscosity is 5-20 mPa.s.

6. The gypsum board according to claim 2 or 5, wherein: The water reducer is selected from one or more of a polycarboxylic acid water reducer and a melamine type sulfonated polycondensate water reducer.

7. The gypsum board according to claim 2 or 5, wherein: The polyvinyl alcohol is selected from any one or more of polyvinyl alcohol PVA2488 and polyvinyl alcohol PVA1788.

8. The gypsum board according to claim 2 or 5, wherein: The foaming agent is an anionic surfactant; Optionally, the anionic surfactant is selected from sodium dodecylbenzene sulfonate, sodium dodecyl sulfate, BASF One or more of SASN812, 3110.

9. The method for preparing a gypsum board according to any one of claims 2 to 8, comprising the following steps: 1) mixing gypsum raw material, zeolite and metakaolin uniformly and calcining the mixture to obtain a mixture 1; 2) mixing silicate cement and the mixture 1 uniformly to obtain a premixed powder; 3) uniformly mixing the premixed powder with polyvinyl alcohol, starch and a water reducing agent to obtain a mixed powder and testing the standard consistency spread thereof to obtain a standard consistency water consumption of the mixed powder; 4) determining mixing water according to the standard consistency water amount in step 3), and uniformly mixing the mixing water and the foaming agent, and then uniformly mixing the mixing water with the mixed powder to obtain gypsum slurry; 5) overlapping and bonding the gypsum slurry with the upper and lower facing papers to form a wet gypsum board; 6) drying the wet gypsum board to obtain the gypsum board; Optionally, the drying in step 6) comprises the following steps: curing the wet gypsum board at room temperature and a relative humidity of 50-90% for 1-3 days; drying at 80-120° C. for 30-90 minutes; and drying at 40-50° C. until the board is completely dry to obtain the gypsum board.

10. A method for treating low-quality gypsum, comprising the following steps: The low-quality gypsum is mixed with zeolite, metakaolin and cement, calcined, aged and cooled for later use; wherein the low-quality gypsum is low-quality desulfurized gypsum, and Cl in the low-quality gypsum is - The content is between 0.03wt.% and 0.9wt.%, Mg 2+ Ion content is not higher than 1000ppmw, Na + The ion content is not higher than 700ppmw.

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