CN114873982B

CN114873982B - Gypsum block with high waterproof strength and preparation method thereof

Info

Publication number: CN114873982B
Application number: CN202210351624.2A
Authority: CN
Inventors: 张赫; 李帆; 丛宇
Original assignee: China National Building Materials Innovation and Technology Research Institute Co Ltd
Current assignee: China National Building Materials Innovation and Technology Research Institute Co Ltd
Priority date: 2022-04-02
Filing date: 2022-04-02
Publication date: 2023-01-06
Anticipated expiration: 2042-04-02
Also published as: CN114873982A

Abstract

A gypsum block with high waterproof strength and a preparation method thereof are disclosed, wherein the preparation raw materials of the gypsum block comprise: 100 parts of gypsum clinker, 0.35 to 3 parts of impurity ion curing agent, 1 to 10 parts of cement, 5 to 10 parts of fly ash, 0.1 to 1.5 parts of fiber and 50 to 90 parts of water. The gypsum block of this application embodiment is lower to the requirement of gypsum raw materials, can adopt the gypsum that contains high concentration impurity ion to prepare the gypsum block that is difficult for returning the frost to wet, water-proof effects is good, intensity is higher.

Description

Gypsum block with high waterproof strength and preparation method thereof

Technical Field

The application relates to but is not limited to the field of gypsum products, in particular to a gypsum block with high waterproof strength and a preparation method thereof.

Background

The gypsum block has the advantages of low production energy consumption, low density, fire resistance, heat preservation and the like, and is a good environment-friendly material. The main raw material of the gypsum block is desulfurized gypsum. K contained in desulfurized gypsum ⁺ 、Na ⁺ 、Mg ²⁺ 、Cl ^- The foreign ions can have adverse effects on the strength of the gypsum block, and cause the block to easily generate adverse phenomena such as frost return, dampness and the like in the subsequent application process. In the past researches, a water washing method is generally adopted to reduce or remove soluble impurities in industrial by-product gypsum, or a high-quality gypsum raw material is selected from a source, but the water washing method has high treatment cost and great influence on the environment, and the production cost of the gypsum block can be increased by selecting the high-quality gypsum raw material.

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 present application.

The embodiment of the application provides a gypsum block with high waterproof strength and a preparation method thereof, the preparation method has low requirements on gypsum raw materials, and gypsum containing high-concentration impurity ions can be adopted to prepare the gypsum block which is not easy to return frost and wet, has a good waterproof effect and is high in strength.

The embodiment of the application provides a gypsum block that waterproof strength is high, gypsum block's preparation raw materials includes:

in the embodiment of the application, the gypsum clinker may contain chloride ions, potassium ions, sodium ions and magnesium ions, the concentration of the chloride ions may be 600ppm to 3000ppm, and the concentration of the potassium ions, the sodium ions and the magnesium ions may be 200ppm to 3000ppm.

In the embodiment of the present application, the impurity ion curing agent may be selected from any one or more of polyvinyl alcohol, polyvinylpyrrolidone, and ethylene-vinyl acetate copolymer.

In the present embodiment, the degree of polymerization of the polyvinyl alcohol may be 3 to 70, and the degree of alcoholysis may be 85 to 89.

In the present embodiment, the cement may be selected from any one or more of portland cement, for example, the cement may be selected from any one or more of portland cement 42.5, portland cement 42.5R, portland cement 52.5, and portland cement 52.5R.

In embodiments herein, the fly ash may be a class I fly ash.

In embodiments of the present application, the fibers may be glass fibers, for example, the fibers may be chopped glass fibers.

The embodiment of the application also provides a preparation method of the gypsum block with high waterproof strength, which comprises the following steps: and doping the impurity ion curing agent into the gypsum block by adopting a dry doping mode.

In an embodiment of the present application, the preparation method may include:

dry-mixing the impurity ion curing agent with gypsum clinker, cement and fly ash to obtain a dry mixture;

adding the dry mixture and the fibers into water, and uniformly stirring to obtain slurry;

and injecting the slurry into a mold, standing, demolding and drying to obtain the gypsum block.

According to the gypsum block and the preparation method thereof, the raw materials are doped with the impurity ion curing agent, and the impurity ion curing agent can effectively control soluble impurity ions (such as chloride ions, potassium ions, sodium ions and magnesium ions) in the gypsum raw materials to migrate to the outer layer of the gypsum block, so that the requirement on the gypsum raw materials can be reduced, and the gypsum block which is not easy to return frost and wet and has higher strength can be prepared by adopting gypsum containing high-concentration impurity ions; and moreover, the impurity ion curing agent can also effectively reduce the permeation of water molecules into the gypsum block, so that the gypsum block obtains a better waterproof effect.

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. Other advantages of the present application may be realized and attained by the instrumentalities and combinations particularly pointed out in the specification and the drawings.

Drawings

The accompanying drawings are included to provide an understanding of the present disclosure and are incorporated in and constitute a part of this specification, illustrate embodiments of the disclosure and together with the examples serve to explain the principles of the disclosure and not to limit the disclosure.

FIG. 1 is a schematic view of gypsum block layering;

FIG. 2 is a graph comparing potassium ion concentrations of layers of gypsum blocks of examples and comparative examples of the present application;

FIG. 3 is a graph comparing the magnesium ion concentration of each layer of gypsum blocks of examples and comparative examples of the present application;

FIG. 4 is a graph comparing the sodium ion concentration of each layer of gypsum blocks of the examples and comparative examples;

FIG. 5 is a graph comparing the chloride ion concentration of each layer of gypsum blocks of the examples and comparative examples;

fig. 6 is a partial external view of gypsum blocks of example 1 of the present application and comparative example 1 after 20 days of storage in the same environment.

Detailed Description

To make the objects, technical solutions and advantages of the present application more apparent, embodiments of the present application will be described in detail below with reference to the accompanying drawings. 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 embodiment of the application, the preparation raw materials of the gypsum block can consist of the following components:

in the embodiment of the application, the gypsum clinker can contain chloride ions, potassium ions, sodium ions and magnesium ions, the concentration of the chloride ions can be 600ppm to 3000ppm, and the concentration of the potassium ions, the sodium ions and the magnesium ions can be 200ppm to 3000ppm.

In the present embodiment, the polyvinyl alcohol may be 0.35 to 3 parts by weight, for example, 0.35, 0.5, 0.75, 1, 1.5 parts by weight, based on 100 parts by weight of the gypsum clinker.

In the present embodiment, the polymerization degree of the polyvinyl alcohol may be 3 to 70, and for example, may be 3, 5, 7, 10, 20, 24, 26, 30, 40, 50, 60, 70; the degree of alcoholysis of the polyvinyl alcohol can be between 85 and 89 and can be, for example, 88.

In the present embodiment, the cement may be selected from any one or more of portland cements.

In the present embodiment, the cement may be selected from any one or more of Portland cement 42.5, portland cement 42.5R, portland cement 52.5 and Portland cement 52.5R.

In the embodiments of the present application, the fly ash may be a class I fly ash.

In the present embodiment, the fibers may be glass fibers.

In embodiments of the present application, the fibers may be chopped glass fibers, for example, chopped glass fibers having a length of about 3mm to 12 mm.

The embodiment of the application also provides a preparation method of the gypsum block with high waterproof strength, which comprises the following steps: and adding the impurity ion curing agent into the gypsum block in a dry doping manner.

In an embodiment of the present application, the impurity ion curing agent may be added to the gypsum block by dry doping, and the preparation method may include:

The desulfurized gypsum used in the following examples and comparative examples for preparing desulfurized gypsum clinker was obtained from north new materials (Tianjin) Co., ltd., wherein the concentrations of chloride ions, potassium ions, sodium ions and magnesium ions were all 1000ppm; the polyvinyl alcohol PVA 2488 is from Shanghai minister-started chemical engineering Co., ltd, and the PVA2688 is from Shanghai minister-started chemical engineering Co., ltd; the ordinary portland cement is from Yongan cement, inc. in Henan; the fly ash is I-grade fly ash and is derived from Yu Union power plants in consolidated city in Henan province; glass fibers were sourced from taansheng composites ltd.

Example 1

The gypsum block of the present example was made from 100 parts by weight of desulfurized gypsum clinker, 0.35 parts by weight of an impurity ion curing agent, 3 parts by weight of cement, 7.5 parts by weight of fly ash, 0.5 parts by weight of glass fiber, and 63 parts by weight of water.

Wherein the impurity ion curing agent is polyvinyl alcohol PVA 2488;

the length of the glass fiber is 4.5mm;

the cement is ordinary Portland cement 42.5R.

The preparation process of the gypsum block of the embodiment comprises the following steps:

(1) Dry-mixing the impurity ion curing agent with gypsum clinker, cement and fly ash to obtain a dry mixture;

(2) Adding the dry mixture and the glass fiber into water, and uniformly stirring to obtain slurry;

(3) Spraying a release agent on a mold, injecting the slurry into the mold with the size of 600mm multiplied by 500mm multiplied by 150mm, standing, demolding and drying to obtain the gypsum block.

Example 2

The gypsum block of the present example was made from 100 parts by weight of desulfurized gypsum clinker, 0.5 parts by weight of an impurity ion curing agent, 2.5 parts by weight of cement, 5 parts by weight of fly ash, 0.5 parts by weight of glass fiber, and 64.5 parts by weight of water.

Wherein the impurity ion curing agent is polyvinyl alcohol PVA 2488;

the length of the glass fiber is 6mm;

the cement is ordinary Portland cement 42.5R.

The gypsum block of this example was prepared in the same manner as in example 1.

Example 3

The gypsum block of the present embodiment is made of 100 parts by weight of desulfurized gypsum clinker, 0.35 part by weight of an impurity ion curing agent, 5 parts by weight of cement, 10 parts by weight of fly ash, 0.3 part by weight of glass fiber, and 60 parts by weight of water.

Wherein the impurity ion curing agent is polyvinyl alcohol PVA 2688;

the length of the glass fiber is 4.5mm;

the cement is ordinary Portland cement 42.5.

Comparative example 1

This comparative example differs from example 1 only in that: no curing agent for impurity ions was added.

Comparative example 2

This comparative example differs from example 2 only in that: the mixing amount of the impurity ion curing agent is 0.2 part by weight; the content of the glass fiber is 0.1 part by weight.

Comparative example 3

This comparative example differs from example 3 only in that: the mixing amount of the impurity ion curing agent is 0.1 part by weight.

Comparative example 4

This comparative example differs from example 1 only in that: the addition mode of the impurity ion curing agent is wet doping, and the preparation process of the gypsum block of the comparative example comprises the following steps:

(1) Dissolving the impurity ion curing agent in water, wherein the weight ratio of the impurity ion curing agent to the water for dissolution is 1;

(2) Dry-mixing gypsum clinker, cement and fly ash to obtain a dry mixture;

(3) Adding the impurity ion curing agent solution obtained in the step (1), the dry mixture obtained in the step (2) and the glass fiber into the residual water, and uniformly stirring to obtain slurry;

Performance detection

1. Curing effect of impurity ions

Cutting off a part of the gypsum block dried to constant weight, and carrying out layered sampling; fig. 1 is a schematic layering view of a gypsum block, as shown in fig. 1, the outermost layer 1, the secondary outer layer 2, the secondary inner layer 3 and the inner core 4 are sequentially arranged from outside to inside during sampling, and the weight of the four layers is approximately the same. And respectively detecting the concentrations of potassium ions, sodium ions, magnesium ions and chloride ions of each layer according to the Chinese building material industry standard JC/T2074-2011 flue gas desulfurization gypsum. The detection results are shown in fig. 2 to 5.

It can be seen that the gypsum blocks prepared by dry doping impurity ion curing agents are adopted in the examples 1 to 3 and the comparative examples 1 to 3, but the concentrations of potassium, sodium, magnesium and chloride ions of the outermost layers of the gypsum blocks of the examples 1 to 3 are far lower than those of the comparative examples; in contrast, the concentrations of potassium, sodium, magnesium and chloride ions in the secondary outer layers of the gypsum blocks of examples 1 to 3 are higher than those in the comparative examples, which indicates that the impurity ion curing agent with a proper doping amount can effectively cure the impurity ions in the blocks, thereby effectively preventing the impurity ions from migrating to the surface layer, and thus solving the problems of block frost return and the like.

Comparing example 1 with comparative example 4, it can be seen that the mixing amount of the impurity ion curing agent in the gypsum block of comparative example 4 is the same as that of example 1, but the curing effect of the impurity ion curing agent of comparative example 4 on the impurity ions is obviously inferior to that of example 1, which shows that the impurity ion curing agent doped in a wet doping manner is not uniformly distributed in the gypsum block, and the migration of the impurity ions is difficult to regularly and effectively prevent. In addition, comparative example 4 it took about 24 to 48 hours to completely dissolve polyvinyl alcohol in water during the preparation of gypsum block, and thus the incorporation of the impurity ion curing agent in a wet incorporation manner greatly reduced the production efficiency of gypsum block.

2. Strength of gypsum block

The mechanical properties of the gypsum blocks prepared in the above examples and comparative examples were tested according to the Chinese building material industry Standard JC/T6982010 "Gypsum Block". The results are shown in Table 1.

TABLE 1 Gypsum block mechanical property test results

It can be seen that the mechanical strength of the gypsum block doped with the impurity ion curing agent in the embodiment in a dry doping manner is obviously superior to that of the gypsum block not doped with the impurity ion curing agent in the comparative example or in a wet doping manner, wherein the breaking load of the gypsum block doped with the impurity ion curing agent in the embodiment in a dry doping manner is obviously superior to that of the gypsum block doped with the impurity ion curing agent in the Chinese building material industry standard JC/T6982010 gypsum block, which is more than or equal to 2000N for the breaking load of the solid block.

3. Waterproof performance of building block

Drying the gypsum blocks to constant weight, completely immersing the gypsum blocks in water for 2 hours after weighing, wiping the surfaces of the gypsum blocks by a wet towel, weighing, and detecting the water absorption rate of the gypsum blocks. The results are shown in Table 2.

TABLE 2 Gypsum Block Water absorption

Name(s)	Dry weight/kg of gypsum block	After the gypsum building block is soaked in water for 2 hours, the weight of the gypsum building block is per kg	Water absorption/%)
				Example 1	52.5	60.7	15.6
Example 2	52.6	61.5	16.9
				Example 3	52.6	61.6	17.1
Comparative example 1	54.8	68.1	24.2
				Comparative example 2	54.2	66.7	23.1
Comparative example 3	54.4	66.8	22.9
				Comparative example 4	52.8	64.2	21.6

It can be seen that, in the examples 1 to 3, the impurity ion curing agents with different doping amounts are added, and the water absorption of the building block after being soaked for 2 hours can be controlled below 18%; and comparative examples 1 to 3 do not or a small amount of impurity ion curing agent is added, the water absorption of the building block after being soaked for 2 hours is over 22%, and the water absorption of the building block without any impurity ion curing agent is the largest, which shows that the proper amount of impurity ion curing agent can effectively improve the waterproof effect of the gypsum building block. In comparative example 4, the impurity ion curing agent was added by wet mixing, which is difficult to prevent water molecules from permeating effectively, because of the problems of uneven mixing, more bubbles, etc. compared with dry mixing. Therefore, the dry doped impurity ion curing agent can effectively reduce the permeation of water molecules into the gypsum block, and has better waterproof effect.

4. Experimental chart for solving problem of frost return

Fig. 6 is a partial external view of the gypsum block of example 1 of the present application and the gypsum block of comparative example 1 after 20 days of storage in the same environment, wherein the left figure is the gypsum block of example 1 and the right figure is the gypsum block of comparative example 1.

It can be seen that the obvious phenomenon of returning frost does not appear on the surface of the gypsum block in embodiment 1 of the present application, and the obvious phenomenon of returning frost appears on the surface of the gypsum block in comparative embodiment 1, which indicates that the impurity ion curing agent can effectively control the migration of soluble impurity ions to the outer layer of the gypsum block.

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

1. A gypsum block with high waterproof strength is prepared from the following raw materials:

the gypsum block is obtained by using the following preparation method:

doping the impurity ion curing agent into the gypsum block in a dry doping mode;

the impurity ion curing agent is selected from one or more of polyvinyl alcohol, polyvinylpyrrolidone and ethylene-vinyl acetate copolymer.

2. The gypsum block of claim 1, wherein the gypsum clinker comprises chloride ions, potassium ions, sodium ions and magnesium ions, wherein the concentration of the chloride ions is 600ppm to 3000ppm, and the concentration of the potassium ions, the sodium ions and the magnesium ions is 200ppm to 3000ppm.

3. The gypsum block of claim 1, wherein the polyvinyl alcohol has a degree of polymerization of 3 to 70 and a degree of alcoholysis of 85 to 89.

4. A gypsum block according to any one of claims 1 to 3, wherein the cement is selected from any one or more of Portland cement 42.5, portland cement 42.5R, portland cement 52.5 and Portland cement 52.5R.

5. The gypsum block of any one of claims 1 to 3, wherein said fly ash is class I fly ash.

6. The gypsum block of any one of claims 1 to 3, wherein said fibers are glass fibers.

7. The gypsum block of claim 6, wherein said fibers are chopped glass fibers.

8. The gypsum block of claim 1, wherein said method of making comprises: