Admixture, lightweight plaster and preparation method thereof

Abstract

The present invention discloses an admixture, a lightweight plaster gypsum and a preparation method thereof, and belongs to the technical field of gypsum. The admixture includes an air entraining agent and a stabilizer. The lightweight plaster gypsum, calculated based on a total of 1000 parts by weight, includes 0 to 500 parts of filler, 0 to 10 parts of water-retaining agent, 0 to 5 parts of retarder, 0.1 to 10 parts of admixture, and the rest is gypsum. The preparation method of the lightweight plaster gypsum includes the following steps: gypsum powder, filler, water-retaining agent, retarder and admixture are sequentially put into a mixer and mixed. The admixture proposed by the present invention is added to gypsum to obtain lightweight plaster gypsum without using light aggregate, and the mixing time can be shortened to 4 minutes, the finishing gypsum process is reduced in interior wall construction, and the strength is higher.

Description

Technical Field

[0001] The invention relates to the technical field of gypsum, and in particular to an admixture, a lightweight plaster gypsum and a preparation method thereof. Background Art

[0002] With the continuous development and progress of plastering gypsum, the plastering gypsum on the market has gradually become lighter, which has led to the production and sales of lightweight aggregates.

[0003] According to the standard requirements of GB / T 28627-2023 "Plastering Gypsum", the biggest feature of lightweight plastering gypsum is that its bulk density is less than 1000kg / m 3 As the main cementitious material, gypsum has a loose bulk density of 800 kg / m 3 ~1000kg / m 3 In order to make the plaster lighter, the most direct way is to add lightweight aggregate.

[0004] Lightweight aggregates mainly include vitrified microspheres, expanded perlite, ceramsite, pumice, expanded vermiculite, etc. The loose bulk density is generally 60kg / m 3 ~600kg / m 3 The main feature is generally an internal porous cavity structure.

[0005] Vitrified microspheres have become a commonly used lightweight aggregate in lightweight indoor plaster gypsum in the construction industry due to their many advantages such as thermal insulation, fire resistance, sound absorption and environmental protection. Some regions also use lightweight aggregates such as expanded perlite, expanded clay and pumice.

[0006] Commercially available lightweight plaster primarily consists of building gypsum powder (hereafter referred to as gypsum powder), vitrified microspheres, and other additives. In actual production, mortar plants first mix the gypsum powder and additives, then add the vitrified microspheres and continue mixing until the powder is uniform. Generally, using a 3m³ mixer at a mixing speed of 40 rpm, the production and mixing process for one ton of lightweight plaster takes approximately 25 minutes.

[0007] Lightweight plasters, which incorporate vitrified microspheres as lightweight aggregate, feel light and easy to apply. However, after hardening, the surface of this type of lightweight plaster is rough and uneven, requiring workers to apply one or two coats of topcoat plaster to cover the unevenness before applying primer and topcoat putty.

[0008] In summary, the main drawbacks of adding vitrified microspheres as lightweight aggregate to lightweight plaster are: the loose bulk density of vitrified microspheres is only 80kg / m 3 ~200kg / m 3, occupies a large area, and the loading and unloading dust pollution is large; when mixed with gypsum and other powders, it is not easy to stir evenly due to the large difference in density; the feeding and mixing time is long, and the production efficiency is low; the surface is rough after construction, and multiple subsequent processes are required to obtain a fine surface; and the strength of lightweight plaster gypsum is low, and its anti-bending dry strength is generally only 1MPa~1.5MPa; in addition, the production of vitrified microspheres is mainly concentrated in the Central Plains. Due to their low density and large volume, the transportation cost is very high, which seriously limits the promotion and application of industrial by-product gypsum.

[0009] Therefore, how to avoid the drawbacks of using vitrified microspheres in lightweight plastering gypsum is an issue that needs to be addressed urgently. Summary of the Invention

[0010] The purpose of the present invention is to overcome the above technical deficiencies and provide an admixture, a lightweight plastering gypsum and a preparation method thereof, which solve the technical drawbacks of the existing lightweight plastering gypsum using vitrified microspheres as lightweight aggregate.

[0011] In order to achieve the above technical purpose, the technical solution of the present invention provides an admixture including an air entraining agent and a stabilizer.

[0012] Furthermore, the additive comprises 40 to 60 parts of air entraining agent and 40 to 60 parts of stabilizer in parts by weight. More preferably, the additive comprises 50 parts of air entraining agent and 50 parts of stabilizer.

[0013] Furthermore, the air-entraining agent is at least one of rosin-based air-entraining agents, alkylbenzene sulfonate-based air-entraining agents, saponin-based air-entraining agents, fatty alcohol sulfonate-based air-entraining agents, and fatty alcohol polyoxyethylene ether-based air-entraining agents. Further preferably, the air-entraining agent is at least one of rosin-based air-entraining agents, alkylbenzene sulfonate-based air-entraining agents, and saponin-based air-entraining agents.

[0014] Furthermore, the stabilizer is at least one of starch ether, magnesium aluminum silicate, polyvinyl alcohol, xanthan gum, guar gum, redispersible latex powder, and modified starch. Further preferably, the stabilizer is at least one of polyvinyl alcohol, modified starch, and xanthan gum.

[0015] As a preferred embodiment, the admixture is 50 parts of rosin-based air entraining agent and 50 parts of polyvinyl alcohol stabilizer, or 50 parts of saponin-based air entraining agent and 50 parts of modified starch stabilizer, or 50 parts of alkylbenzene sulfonate-based air entraining agent and 50 parts of xanthan gum stabilizer.

[0016] Furthermore, the fineness of the admixture is 60 mesh to 400 mesh, and the loose bulk density is 200 kg / m 3 ~1000kg / m 3 , pH value is 6 to 9. Further preferably, the fineness of the admixture is 120 mesh to 200 mesh, and the loose bulk density is 550 kg / m 3~650kg / m 3 , pH value is 7.

[0017] The present invention also provides a lightweight plastering gypsum, which comprises, based on a total of 1,000 parts by weight, 0-500 parts of filler, 0-10 parts of water-retaining agent, 0-5 parts of retarder, 0.1-10 parts of the aforementioned admixtures, and the remainder being gypsum powder. More preferably, the filler comprises 0-300 parts, the water-retaining agent comprises 2-3 parts, the retarder comprises 0.5-2 parts, the admixtures comprise 0.2-2 parts, and the remainder being gypsum powder.

[0018] Furthermore, the filler is at least one of calcium carbonate powder, fly ash and slag powder, with a mesh size of 60 to 800 mesh. Further preferably, the filler is calcium carbonate powder, with a mesh size of 180 to 350 mesh and a loose bulk density of 1000 kg / m 3 ~1 200kg / m 3 .

[0019] Furthermore, the water-retaining agent is at least one of hydroxypropyl methylcellulose ether, hydroxyethyl methylcellulose ether and hydroxyethyl cellulose ether. Further preferably, the water-retaining agent is hydroxypropyl methylcellulose ether.

[0020] Furthermore, the retarder is at least one of animal protein, modified amino acid, EDTA and tartaric acid. More preferably, the retarder is modified amino acid.

[0021] Furthermore, the gypsum powder is at least one of building gypsum powder, natural gypsum, desulfurized gypsum, phosphogypsum, citric acid gypsum, and salt gypsum. Further preferably, the gypsum is phosphogypsum, and has a flexural dry strength of 5.0 MPa to 8.0 MPa and a compressive dry strength of 12.0 MPa to 18.0 MPa.

[0022] Furthermore, the present invention also provides a method for preparing the above-mentioned lightweight plaster gypsum, comprising the following steps: sequentially putting gypsum powder, filler, water-retaining agent, retarder and admixture into a mixer and mixing them.

[0023] Furthermore, the mixing speed is 40 to 150 r / min, and the mixing time is 4 to 8 minutes. More preferably, the mixing speed is 120 r / min, and the mixing time is 4 minutes.

[0024] The admixture provided by the present invention is added to gypsum to obtain lightweight plastering gypsum without using light aggregates such as vitrified microspheres.

[0025] Furthermore, after adding a predetermined amount of water, the lightweight plastering gypsum is mechanically stirred to obtain gypsum mortar that can be used by workers for construction.

[0026] Furthermore, the applicant unexpectedly discovered that during the process of adding water and stirring in the lightweight plaster, the air entraining agent in the admixture is rapidly dispersed, and dense small bubbles are formed in the mortar system under high-speed stirring.

[0027] Furthermore, after the stabilizer is dissolved, it can maintain the stability of the bubbles and prevent the bubbles from bursting, thereby obtaining a plaster with uniform pores.

[0028] Furthermore, the applicant has proved through a large number of experiments that the amount of bubbles formed and the stability of the bubbles are directly related to the mixing ratio of the air entraining agent and the stabilizer in the admixture.

[0029] Furthermore, due to the addition of dense bubbles in the mortar system, the above-mentioned gypsum mortar without the addition of lightweight aggregate has achieved the basic technical characteristics of the gypsum mortar with the addition of lightweight aggregate such as vitrified microspheres.

[0030] Furthermore, because the bubbles formed by the admixture replace the porous cavity structure of the vitrified microspheres, the volume density of the obtained gypsum mortar is reduced.

[0031] Compared with the prior art, the present invention has the following beneficial effects:

[0032] The lightweight plastering gypsum preparation method proposed in the present invention does not require the purchase of vitrified microspheres; there is no vitrified microsphere dust pollution; the feeding and mixing time during production can be shortened to 4 minutes; the plastering process is reduced during interior wall construction; the flexural dry strength is 1.8MPa to 3.0MPa, the compressive dry strength is 3.0MPa to 8.0MPa, and the bulk density is less than 1000kg / m 3 ; It can promote the promotion and application of industrial by-product gypsum; and significantly reduce the overall cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 This is a picture of a gypsum specimen made from the lightweight plaster gypsum of Example 4 of the present invention;

[0034] Figure 2 This is a picture of a gypsum specimen made from the lightweight plaster gypsum of Example 7 of the present invention.

[0035] Figure 3 1 is a cross-sectional picture of the lightweight plastering gypsum of Example 4 of the present invention and Comparative Example 1;

[0036] Figure 4 This is a picture of a gypsum specimen made from the lightweight plastering gypsum of Comparative Example 1 of the present invention after being scraped with the topcoat plaster;

[0037] Figure 5 This is a picture of a gypsum specimen made from the lightweight plastering gypsum of Example 4 of the present invention after being scraped and coated with primer putty. DETAILED DESCRIPTION

[0038] This specific embodiment provides an admixture including an air entraining agent and a stabilizer.

[0039] In certain embodiments, the composition comprises 40-60 parts by weight of an air-entraining agent and 40-60 parts by weight of a stabilizer. Furthermore, the air-entraining agent is at least one of rosin-based air-entraining agents, alkylbenzene sulfonate-based air-entraining agents, saponin-based air-entraining agents, fatty alcohol sulfonate-based air-entraining agents, and fatty alcohol polyoxyethylene ether-based air-entraining agents. Further preferably, the air-entraining agent is one of rosin-based air-entraining agents, alkylbenzene sulfonate-based air-entraining agents, and saponin-based air-entraining agents. The stabilizer is at least one of starch ether, magnesium aluminum silicate, polyvinyl alcohol, xanthan gum, guar gum, redispersible latex powder, and modified starch. Further preferably, the stabilizer is one of polyvinyl alcohol, modified starch, and xanthan gum.

[0040] Furthermore, the admixture, calculated by weight, comprises 50 parts of an air entraining agent and 50 parts of a stabilizer; the admixture is 50 parts of a rosin-based air entraining agent and 50 parts of a polyvinyl alcohol stabilizer, or the admixture is 50 parts of a saponin-based air entraining agent and 50 parts of a modified starch stabilizer, or the admixture is 50 parts of an alkylbenzene sulfonate-based air entraining agent and 50 parts of a xanthan gum stabilizer; the fineness of the admixture is 120 mesh to 200 mesh, and the loose bulk density is 550 kg / m 3 ~650kg / m 3 , pH value is 7.

[0041] This embodiment also provides a lightweight plastering gypsum, which, calculated by weight, comprises 0-300 parts filler, 2-3 parts water-retaining agent, 0.5-2 parts retarder, 0.2-2 parts of the aforementioned admixtures, and the remainder being gypsum powder. Furthermore, the filler is at least one of calcium carbonate powder, fly ash, and slag powder, with a mesh size of 60-800 mesh. Furthermore, the water-retaining agent is at least one of hydroxypropyl methylcellulose ether, hydroxyethyl methylcellulose ether, and hydroxyethyl cellulose ether. Furthermore, the retarder is at least one of animal protein, modified amino acids, EDTA, and tartaric acid. Furthermore, the gypsum powder is at least one of building gypsum powder, natural gypsum, desulfurized gypsum, phosphogypsum, citric acid gypsum, and salt gypsum.

[0042] In some embodiments, the filler is calcium carbonate powder with a mesh size of 180 to 350 mesh and a loose bulk density of 1000 kg / m 3 ~1 200kg / m 3The water-retaining agent is hydroxypropyl methylcellulose ether, the viscosity of the water-retaining agent ranges from 10,000 cps to 20,000 cps, and the water retention rate is greater than 90%; the retarder is a modified amino acid; the gypsum powder is phosphogypsum, with a dry flexural strength of 5.0 MPa to 8.0 MPa and a dry compressive strength of 12.0 MPa to 18.0 MPa.

[0043] In addition, this specific embodiment also provides a method for preparing the aforementioned lightweight plaster, comprising the following steps: sequentially adding gypsum powder, filler, water-retaining agent, retarder, and admixture into a mixer and mixing; the mixing speed is 20 to 150 r / min, and the mixing time is 4 to 8 minutes. The mixer for mixing can be a plowshare mixer, a ribbon mixer, a dual-shaft zero-gravity mixer, or the like, and has a volume of 1 to 10 m³. The packaging equipment can be a valve-type dry mortar packaging machine or an open-type dry mortar packaging machine. The packaging bags can be valve bags or open-type bags.

[0044] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention will be further described in detail below in conjunction with the accompanying drawings and examples. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. The filler in the following examples or comparative examples is calcium carbonate powder with a mesh size of 325 and a loose bulk density of 1000 kg / m 3 ~1 200kg / m 3 The water-retaining agent is hydroxypropyl methylcellulose ether with a viscosity range of 10,000 cps to 20,000 cps and a water retention rate of >90%; the retarder is a modified amino acid; the gypsum is phosphogypsum with a flexural dry strength of 5.0 MPa to 8.0 MPa and a compressive dry strength of 12.0 MPa to 18.0 MPa.

[0045] Example 1

[0046] This embodiment proposes an admixture, which includes 50 parts of an air entraining agent and 50 parts of a stabilizer, calculated by weight. The air entraining agent is a rosin-based air entraining agent; and the stabilizer is polyvinyl alcohol.

[0047] The fineness of the admixture proposed in this embodiment is 120 mesh to 200 mesh, and the loose bulk density is 600 kg / m 3 , pH value is 7.

[0048] Example 2

[0049] This embodiment proposes an admixture, which includes 50 parts of an air entraining agent and 50 parts of a stabilizer, calculated by weight. The air entraining agent is a saponin-based air entraining agent; and the stabilizer is modified starch.

[0050] The fineness of the admixture proposed in this embodiment is 120 mesh to 200 mesh, and the loose bulk density is 550 kg / m 3 , pH value is 7.

[0051] Example 3

[0052] This embodiment proposes an admixture, which includes 50 parts of an air entraining agent and 50 parts of a stabilizer, calculated by weight. The air entraining agent is an alkylbenzene sulfonate air entraining agent; and the stabilizer is xanthan gum.

[0053] The fineness of the admixture proposed in this embodiment is 120 mesh to 200 mesh, and the loose bulk density is 650 kg / m 3 , pH value is 7.

[0054] Example 4

[0055] This embodiment provides a lightweight plaster gypsum, which, calculated in parts by weight, includes 2.5 parts of a water-retaining agent, 2 parts of a retarder, 1 part of the admixture of Example 1, and the remainder is gypsum powder; the water-retaining agent is hydroxypropyl methylcellulose ether; the retarder is a modified amino acid; and the gypsum powder is phosphogypsum.

[0056] The preparation method comprises the following steps: sequentially putting gypsum powder, water retaining agent, retarder and admixture into a mixer and mixing them; the mixing speed is 120r / min, the mixing time is 4min, and after the powder is evenly mixed, it can be packaged for use.

[0057] Example 5

[0058] This embodiment provides a lightweight plaster gypsum, which, calculated by weight in total of 1,000 parts, includes 300 parts of filler, 2.5 parts of water-retaining agent, 1.5 parts of retarder, 1 part of the admixture of Example 1, and the remainder is gypsum powder; the water-retaining agent is hydroxypropyl methylcellulose ether; the retarder is a modified amino acid; and the gypsum powder is phosphogypsum.

[0059] The preparation method comprises the following steps: sequentially putting gypsum powder, filler, water retaining agent, retarder and admixture into a mixer and mixing them; the mixing speed is 120r / min, the mixing time is 4min, and after the powder is evenly mixed, it can be packaged for use.

[0060] Example 6

[0061] This embodiment provides a lightweight plaster gypsum, which, calculated by weight in total of 1,000 parts, includes 2.5 parts of a water-retaining agent, 2 parts of a retarder, 1 part of the admixture of Example 2, and the remainder is gypsum powder; the water-retaining agent is hydroxypropyl methylcellulose ether; the retarder is a modified amino acid; and the gypsum powder is phosphogypsum.

[0062] The preparation method comprises the following steps: sequentially putting gypsum powder, water retaining agent, retarder and admixture into a mixer and mixing them; the mixing speed is 120r / min, the mixing time is 4min, and after the powder is evenly mixed, it can be packaged for use.

[0063] Example 7

[0064] This embodiment provides a lightweight plaster gypsum, which, calculated in parts by weight, includes 300 parts of filler, 2.5 parts of water-retaining agent, 1.5 parts of retarder, 1 part of the admixture of Example 2, and the rest is gypsum powder; the water-retaining agent is hydroxypropyl methylcellulose ether; the retarder is a modified amino acid; and the gypsum powder is phosphogypsum.

[0065] The preparation method comprises the following steps: sequentially putting gypsum powder, filler, water retaining agent, retarder and admixture into a mixer and mixing them; the mixing speed is 120r / min, the mixing time is 4min, and after the powder is evenly mixed, it can be packaged for use.

[0066] Example 8

[0067] This embodiment provides a lightweight plaster gypsum, which, calculated by weight, comprises 2.5 parts of a water-retaining agent, 2 parts of a retarder, 1 part of the admixture of Example 3, and the remainder being gypsum powder. The water-retaining agent is hydroxypropyl methylcellulose ether; the retarder is a modified amino acid; and the gypsum powder is phosphogypsum.

[0068] The preparation method comprises the following steps: sequentially putting gypsum powder, water retaining agent, retarder and admixture into a mixer and mixing them; the mixing speed is 120r / min, the mixing time is 4min, and after the powder is evenly mixed, it can be packaged for use.

[0069] Example 9

[0070] This embodiment provides a lightweight plaster gypsum, which, calculated by weight, comprises 300 parts of filler, 2.5 parts of water-retaining agent, 1.5 parts of retarder, 1 part of the admixture of Example 3, and the remainder is gypsum powder. The water-retaining agent is hydroxypropyl methylcellulose ether; the retarder is a modified amino acid; and the gypsum powder is phosphogypsum.

[0071] The preparation method comprises the following steps: sequentially putting gypsum powder, filler, water retaining agent, retarder and admixture into a mixer and mixing them; the mixing speed is 120r / min, the mixing time is 4min, and after the powder is evenly mixed, it can be packaged for use.

[0072] Comparative Example 1

[0073] The difference between this comparative example and Example 9 is that 60 parts of vitrified microspheres are used instead of 60 parts of filler. Specifically, this example provides a lightweight plaster gypsum, which, calculated by weight, comprises 240 parts of filler, 60 parts of vitrified microspheres, 2.5 parts of water-retaining agent, 1.5 parts of retarder, and the remainder is gypsum; the water-retaining agent is hydroxypropyl methylcellulose ether; the retarder is a modified amino acid; and the gypsum powder is phosphogypsum.

[0074] The preparation method includes the following steps: gypsum powder, filler, water-retaining agent and retarder are sequentially put into a mixer and mixed at a mixing speed of 120 r / min, and the feeding and mixing time is 4 minutes; then the mixing speed is reduced to 40 r / min, and vitrified microbeads are added and mixed until the powder is uniform. To prevent the vitrified microbeads from breaking during the mixing process, the mixing speed is 40 r / min and the mixing time is 16 minutes.

[0075] In this comparative example, the light aggregate of the lightweight plaster is vitrified microspheres with a particle size of 40 to 140 meshes and a loose bulk density of 120 kg / m 3 , the volume water absorption rate is 40%.

[0076] Comparative Example 2

[0077] The only difference between this comparative example and Example 9 is that there is no stabilizer in the admixture.

[0078] Comparative Example 3

[0079] The only difference between this comparative example and Example 9 is that the air entraining agent in the admixture is 80 parts and the stabilizer is 20 parts.

[0080] Comparative Example 4

[0081] The only difference between this comparative example and Example 9 is that the air entraining agent in the admixture is 20 parts and the stabilizer is 80 parts.

[0082] Related trials

[0083] The lightweight plastering gypsum proposed in Examples 4 to 9 and Comparative Examples 1 to 4 was mixed with water to prepare gypsum test pieces for performance testing. The test results are shown in Tables 1 and 2.

[0084] Table 1 Gypsum performance test results of each embodiment and comparative example 1

[0085]

[0086] Table 2 Gypsum performance test results of Example 9 and comparative examples

[0087]

[0088] As can be seen from Table 1, according to the standard requirements of GB / T 28627-2023 "Plastering Gypsum", the flexural strength of lightweight plastering gypsum is not less than 1.0 MPa, the compressive strength is not less than 2.5 MPa, and the bulk density is less than 1 000 kg / m 3 The strength of the gypsums of Examples 4 to 9 all meet the requirements, and the bulk density meets the requirements of lightweight plaster. However, in Comparative Example 1, vitrified microspheres are added, and although the bulk density is slightly lower, the strength is also lower.

[0089] As shown in Table 2, in Comparative Examples 2 and 3, where no stabilizer or a low amount of stabilizer were used, the lightweight plaster thickened rapidly, resulting in a short working time and failing to meet construction requirements. Comparative Example 4 also suffered from insufficient air entrainment, a high wet density, a heavy feel during construction, and the product easily sagged on the wall. This demonstrates that the technical effectiveness of the admixture proposed in this invention is the result of the combined effects of the components in specific amounts.

[0090] The gypsum of Examples 4 and 7 was used to prepare gypsum test pieces. Figure 1 and 2 As shown, it can be seen that the surface of the gypsum specimen is relatively smooth.

[0091] The cross section of the gypsum mortar of Example 4 and Comparative Example 1 is as follows Figure 3 As shown, the left is Example 4 and the right is Comparative Example 1. It can be observed that the internal pores in the left picture are evenly dispersed, while the right picture has glass beads and a small amount of large bubbles.

[0092] The gypsum test piece prepared from the gypsum of Comparative Example 1 is as follows Figure 4 As shown, the surface is rough and needs to be treated with a covering plaster before the base putty can be applied. The plaster specimen prepared in Example 4 is as shown in FIG. Figure 5 As shown, the surface is flat and can be leveled by applying primer putty without the need for a covering, thus saving the material for the covering plaster.

[0093] Other beneficial effects of the present invention:

[0094] 1) Reduce the use of natural resources. This not only significantly reduces the use of natural resources such as vitrified microspheres, which is equivalent to protecting the natural ecology, but also increases the comprehensive utilization rate of solid waste gypsum, contributing to national environmental protection.

[0095] 2) Reduced feeding and mixing time. By feeding and mixing the materials once and evenly, the feeding and mixing time for producing one ton of plaster gypsum mortar using the same 3m³ mixing equipment is shortened to approximately 4 minutes.

[0096] 3) Reduce equipment cleaning. There is no need to completely clean out the equipment when producing other dry mortars, and there is no need to worry about contamination from vitrified microspheres.

[0097] 4) Widely increase the strength of lightweight plaster. Increase the strength of mortar while ensuring the construction feel and coating rate.

[0098] 5) Reduce the number of internal wall plastering and plastering construction processes. Reduce the number of plastering and plastering processes.

[0099] 6) Reduce the overall cost of interior wall plastering. By using a synthetic admixture to replace lightweight aggregates such as vitrified microspheres and ceramsite to produce lightweight plaster, the material cost of lightweight plaster in areas without vitrified microspheres is reduced, and the material of the finishing plaster is saved.

[0100] The specific embodiments of the present invention described above do not limit the scope of protection of the present invention. Any other corresponding changes and modifications made based on the technical concept of the present invention should be included in the scope of protection of the claims of the present invention.

Claims

1. A lightweight plastering gypsum, characterized in that: The invention relates to a novel composite material comprising 1,000 parts by weight, including 0 to 500 parts of filler, 0 to 10 parts of water-retaining agent, 0 to 5 parts of retarder and 0.1 to 10 parts of admixture, with the remainder being gypsum powder. The amount of filler, water-retaining agent and retarder is not zero. The admixture comprises 40 to 60 parts of air-entraining agent and 40 to 60 parts of stabilizer, calculated by weight. The air-entraining agent is at least one of rosin-based air-entraining agent, alkylbenzene sulfonate-based air-entraining agent, saponin-based air-entraining agent, fatty alcohol sulfonate-based air-entraining agent and fatty alcohol polyoxyethylene ether-based air-entraining agent. The stabilizer is at least one of starch ether, magnesium aluminum silicate, xanthan gum, guar gum and modified starch. The fineness of the admixture is 60 mesh to 400 mesh, and the loose bulk density is 200 kg / m 3 ~1 000kg / m 3 , pH value is 6-9; the water retaining agent is at least one of hydroxypropyl methyl cellulose ether, hydroxyethyl methyl cellulose ether and hydroxyethyl cellulose ether; the retarder is at least one of animal protein, modified amino acid, EDTA and tartaric acid; the filler is at least one of calcium carbonate powder, fly ash and slag powder; Described lightweight plastering gypsum is prepared by following steps: The gypsum powder, filler, water retaining agent, retarder and admixture are sequentially put into a mixer and mixed at a mixing speed of 40 to 150 r / min and a mixing time of 4 to 8 minutes.

2. The lightweight plaster according to claim 1, characterized in that The gypsum powder is building gypsum powder.

3. The lightweight plaster according to claim 2, characterized in that The building gypsum powder is obtained from at least one of natural gypsum, desulfurized gypsum, phosphogypsum, citric acid gypsum and salt gypsum.

4. A method for preparing the lightweight plaster according to any one of claims 1 to 3, characterized in that: The following steps are involved: The gypsum powder, filler, water retaining agent, retarder and admixture are sequentially put into a mixer and mixed to obtain the product.

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