Easy-to-disperse, high-workability and light-weight plastering gypsum material, slurry and preparation method thereof

Abstract

The invention provides an easy-to-disperse and high-workability lightweight plastering gypsum material, slurry and a preparation method thereof, and belongs to the technical field of building materials. The easy-to-disperse and high-workability lightweight plastering gypsum material comprises building gypsum powder, a reaction activity regulator, a volcanic ash active material, a mineral powder filler, an expanded lightweight aggregate, a setting time regulator and a premixed master batch. The light plastering gypsum material has the advantages of being easy to disperse after being added with water, capable of being rapidly stirred into uniform slurry without caking, good in slurry workability, long in operable time, smooth in smearing performance and the like, and solves the problems that existing light plastering gypsum is not easy to disperse after being added with water and stirred, the slurry is not uniform and has caking, the operable time is short, the smearing performance is poor, and the plastering effect is poor. And the construction survival efficiency is low.

Description

Technical Field

[0001] The invention belongs to the technical field of building materials, and relates to a gypsum-based wall plastering and leveling material, in particular to an easily dispersible, highly workable and lightweight plastering gypsum material, a slurry and a preparation method thereof. Background Art

[0002] Gypsum is a green and environmentally friendly building material, and its production energy consumption is only one-fourth of that of cement. Using lightweight plastering gypsum as a plastering and leveling material for walls and ceilings in non-humid areas of indoor buildings can greatly reduce the amount of high-energy cement, save energy and reduce carbon emissions, and expand the comprehensive utilization of industrial by-product gypsum.

[0003] With the continuous improvement of my country's process equipment level and labor costs, the high construction efficiency and economic benefits of lightweight plaster gypsum are prompting the transformation of wall leveling materials from traditional cement mortar to lightweight plaster gypsum that is easy to disperse and has high workability and can be sprayed mechanically. Lightweight plaster gypsum that is easy to disperse and has good workability can be used by adding water and mixing it manually or by machine at the construction site. It can be quickly constructed, reduce the number of times the ruler is scraped and leveled, and improve construction efficiency. However, with the current application and promotion of lightweight plaster gypsum, the products on the market have the disadvantages of not being easy to disperse evenly after adding water, easy to clump together, thickening of the slurry in the later stage and becoming slag, easy to produce plastic cracking and adhesion and falling off. Summary of the invention

[0004] In order to solve the above-mentioned technical problems, the present invention provides an easily dispersible, highly workable lightweight plastering gypsum material, slurry and a preparation method thereof. The easily dispersible, highly workable lightweight plastering gypsum material of the present invention is easily dispersed when stirred with water, and can be quickly stirred into a uniform slurry without agglomerates, with a long open time and superior construction and workability, which can be quickly applied to the wall for leveling, reducing the number of times construction workers apply and scrape the slurry; in addition, since the dry powder has the property of being easily dispersed when adding water, the lightweight plastering gypsum material of the present invention can be mechanically sprayed for construction, further improving the efficiency of construction operations.

[0005] To solve the above problems, the present invention is implemented through the following technical solutions:

[0006] The first invention object of the present invention is:

[0007] Provided is a light-weight plastering gypsum material that is easily dispersible and highly workable, comprising the following components in parts by weight:

[0008] 50.0-95.0 parts of building gypsum powder, 0.5-10.0 parts of reaction activity regulator, 0-30.0 parts of volcanic ash active material, 0.5-40.0 parts of mineral powder filler, 3.0-15.0 parts of expanded lightweight aggregate, 0.05-0.2 parts of setting time regulator, and 2.0 parts of premixed masterbatch;

[0009] The premixed masterbatch comprises the following components in parts by weight:

[0010] 5.0-20.0 parts of cellulose ether, 1.0-5.0 parts of etherified starch, 0-40.0 parts of bentonite, 2.5-10.0 parts of polyalkylene oxide block copolymer, 0.1-1.0 parts of α-olefin sulfonate, 0.5-2.5 parts of modified polycarboxylate, and 21.5-91.0 parts of mineral powder filler;

[0011] The polyalkylene oxide block copolymer is a powdery type based on a nonionic polyalkylene oxide block copolymer;

[0012] The further optimization of the easily dispersible, highly workable and lightweight plastering gypsum material of the present invention is as follows:

[0013] It includes one or more of the following features:

[0014] The building gypsum powder is any one of natural gypsum, desulfurized gypsum, phosphogypsum or a mixture of the gypsum powder and the calcined gypsum powder, the calcination temperature range is 140-220°C, the initial setting time is ≥3min, the final setting time is ≤30min, the chloride ion content is ≤900ppm, and the specific surface area is 500-900m 2 / kg, anhydrous phase AⅢ content ≤5.0%, semi-aqueous phase content ≥75%, dihydrate phase content ≤4.0%;

[0015] The reaction activity regulator is one or a mixture of slaked lime, silicate cement, sulphoaluminate cement and aluminium sulfate;

[0016] The volcanic ash active material is one or a mixture of fly ash from power plants, ground blast furnace slag powder, silica fume, and high-altitude land;

[0017] The mineral powder filler is one or a mixture of limestone powder, dolomite powder and talcum powder, and the fineness is 200-400 mesh;

[0018] The cellulose ether is one or a mixture of hydroxyethyl methyl cellulose HEMC and hydroxypropyl methyl cellulose HPMC;

[0019] The etherified starch is made from natural polysaccharides and is highly etherified and modified.

[0020] The bentonite is sodium-based bentonite with a specific surface area of ​​15 to 25 m 2 / g;

[0021] The polyalkylene oxide block copolymer is a surfactant of a non-ionic polyalkylene oxide block copolymer;

[0022] The α-olefin sulfonate is sodium α-olefin sulfonate;

[0023] The modified polycarboxylate is a modified polycarboxylic acid high-efficiency water reducing agent.

[0024] The further optimization of the easily dispersible, highly workable and lightweight plastering gypsum material of the present invention is as follows:

[0025] The expanded lightweight aggregate is closed-cell expanded perlite baked in a gas furnace or an electric furnace; and / or

[0026] The closed-cell expanded perlite has a main particle size distribution of 20 mesh to 120 mesh; and / or

[0027] The closed-cell expanded perlite has a loose bulk density of 80 to 120 kg / m 3 .

[0028] The further optimization of the easily dispersible, highly workable and lightweight plastering gypsum material of the present invention is as follows:

[0029] The setting time regulator is:

[0030] Calcium sulfate, added with one or more of modified amino acid salts, citric acid and its salts, tartaric acid and its salts, boric acid and its salts, phosphates; and / or

[0031] The calcium sulfate has a specific surface area of ​​6000 to 9000 m 2 / kg of calcium sulfate dihydrate powder; and / or

[0032] The calcium sulfate dihydrate powder is one or a mixture of ultra-finely ground natural dihydrate gypsum, desulfurized gypsum and phosphogypsum.

[0033] The further optimization of the easily dispersible, highly workable and lightweight plastering gypsum material of the present invention is as follows:

[0034] The method for preparing the premixed masterbatch comprises the following preparation steps:

[0035] S1. Weigh cellulose ether, etherified starch, bentonite, polyalkylene oxide block copolymer, α-olefin sulfonate, modified polycarboxylate in proportion, and balance to 100 parts with mineral powder filler;

[0036] S2. Add the weighed raw materials into a small mixer and stir for 15 to 30 minutes. Take out 10 portions of the premix and add them into the mixer again and stir for 5 to 10 minutes to prepare a premix masterbatch.

[0037] The second object of the present invention is:

[0038] Provided is a method for preparing the above-mentioned easily dispersible, highly workable and lightweight plastering gypsum material, which comprises the following preparation steps:

[0039] S1. The building gypsum powder, the reactive regulator, the volcanic ash active material, the mineral powder filler, the setting time regulator and the premixed masterbatch are respectively metered and transported to the mixer for high-speed mixing;

[0040] S2. The expanded lightweight aggregate is metered into a mixer and mixed evenly to prepare a lightweight plaster gypsum material that is easily dispersed and highly workable.

[0041] The third invention object of the present invention is:

[0042] Provided is an easily dispersible, highly workable, lightweight plastering gypsum slurry prepared by using the aforementioned easily dispersible, highly workable, lightweight plastering gypsum material:

[0043] The invention is mainly prepared by mixing the easily dispersible, highly workable and lightweight plastering gypsum material and water, and the weight ratio thereof is (1.2-2.5):1.

[0044] The easily dispersible, highly workable and lightweight plastering gypsum material of the present invention has the following outstanding effects:

[0045] 1. The powder is easily dispersed when stirred with water, and is evenly distributed without agglomeration, which solves the existing plastering gypsum. The good workability can be mechanized for continuous spraying construction, greatly improving construction efficiency and shortening the construction period.

[0046] 2. In addition, good workability is also reflected in the fact that the slurry has low resistance to application, does not stick to the knife, does not sag, has a long open time, is easy to scrape and smooth, and greatly improves on-site construction efficiency.

[0047] 3. According to GB / T 28627-2012 "Plastering Gypsum" test, the physical properties are qualified, including operating time ≥60min, water retention rate ≥80%, flexural strength ≥1.3MPa, compressive strength ≥2.6MPa, tensile bond strength ≥0.35MPa, bulk density ≤1000kg / m 3 In particular, the tensile bonding strength with the base layer is high, and the tensile failure mode is cohesive failure of the plaster, which solves the problem of easy hollowing of the existing plaster.

[0048] 4. By modifying and optimizing the gypsum powder particles, adjusting the particle size of the lightweight aggregate in the formula, and optimizing the particle grading of the overall formula, the problem of plastic cracking of lightweight plastering gypsum is solved. The initial intense hydration degree of gypsum is further inhibited by the reaction activity regulator, reducing the plastic cracking caused by the rapid initial water loss of lightweight plastering gypsum slurry.

[0049] 5. The synergistic effect of the selected medium-low viscosity modified cellulose ether and etherified starch in the premixed masterbatch increases the anti-sagging type and superior construction feel of the lightweight plaster gypsum slurry. The principle is to improve the yield stress of the lightweight plaster gypsum slurry through the adsorption of branched etherified starch and gelling materials. The layered silicate mineral powder in the premixed masterbatch improves the smoothness of the lightweight plaster gypsum slurry and further improves the thixotropy of the slurry. The premixed masterbatch contains polyalkylene oxide block copolymers and α-olefin sulfonates to improve the wettability of the lightweight plaster gypsum powder after adding water. The premixed masterbatch contains modified polycarboxylates, whose molecules are composed of two parts: hydrophilic groups and hydrophobic groups. The hydrophobic groups are directional adsorbed on the surface of gypsum particles, and the hydrophilic groups point to the aqueous solution, so that the surface of the gypsum particles has the same charge. The repulsive force separates the gypsum particles, releases the flocculated structure ions, and increases the fluidity. The various substances in the premixed masterbatch work together to improve the mixing and dispersibility of lightweight plaster gypsum, especially solving the problem of phosphogypsum with fine powder particles being easy to agglomerate. The lime in the formula and cement adjust the reactivity of calcium sulfate and improve the performance stability of the formula.

[0050] The present invention improves the dispersibility of light plaster gypsum materials when adding water through all or part of the above corresponding technical measures, and can be quickly stirred into a uniform, non-agglomerated, highly thixotropic slurry, which has the advantages of good slurry workability, long operability time, smooth application, etc., and solves the problems of existing light plaster gypsum that it is difficult to disperse when adding water and stirring, the slurry is uneven and agglomerated, the operability time is short, the application is poor, and the construction efficiency is low. The product prepared by the present invention can be applied manually or mechanically sprayed. When the manual application is used, the slurry is easy to stir evenly, the slurry has good thixotropy, and the construction efficiency is improved. When mechanical spraying is used, the slurry is smooth, easy to extrude and spray, and the wear on the pipe wall is small, and the slurry sprayed on the wall does not flow or fall. DETAILED DESCRIPTION

[0051] In order to make the application, technical scheme and advantages of the present invention clearer, the present invention is described in detail in conjunction with specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not limited to the present invention. All simple improvements to the preparation method of the present invention under the premise of the present invention are within the protection scope of the present invention.

[0052] Example 1

[0053] A method for preparing an easily dispersible, highly workable and lightweight plaster gypsum slurry, comprising the following preparation steps:

[0054] S1. The building gypsum powder, the reactive modifier, the volcanic ash active material, the mineral powder filler, the setting time modifier and the premixed masterbatch are respectively measured and transported to the mixer for high-speed mixing;

[0055] S2. The expanded lightweight aggregate is metered into a mixer and mixed evenly to prepare an easily dispersible, highly workable lightweight plaster gypsum material;

[0056] S3. Mix the easily dispersible, highly workable lightweight plastering gypsum material prepared in step S2 with water to prepare a lightweight plastering gypsum slurry, wherein the weight ratio is: (1.2-2.5):1.

[0057] Used in Example 1:

[0058] The building gypsum powder is the gypsum powder calcined at 175℃ from the desulfurized gypsum of the power plant. The gypsum powder after aging treatment has an initial setting time of 11min, a final setting time of 16min, an anhydrous phase AⅢ content of 2%, a hemihydrate calcium sulfate content of 91%, a dihydrate calcium sulfate content of 2.0%, and a specific surface area of ​​550m 2 / kg, chloride ion content 360ppm; (desulfurized gypsum contains 5-10% impurities)

[0059] The reaction activity regulator is slaked lime with a fineness of 400 mesh;

[0060] The volcanic ash active material was purchased from fly ash from a power plant, with a fineness of 325 mesh;

[0061] The mineral powder filler is limestone powder with a fineness of 250 mesh;

[0062] The expanded lightweight aggregate is a closed-cell expanded perlite baked in a gas furnace, and its free bulk density is 100kg / m 3 , the main particle size distribution is 40-70 mesh;

[0063] The setting time regulator has a specific surface area of ​​6500m 2 / kg natural dihydrate gypsum powder and tartaric acid gypsum retarder mixed powder, the mixing ratio is 1:9;

[0064] The premixed masterbatch 1 is premixed by the following materials in parts by weight, specifically 7.5 parts of hydroxyethyl methyl cellulose ether (HEMC), 1 part of etherified starch, 2.5 parts of polyalkylene oxide block copolymer, 0.1 part of α-olefin sulfonate, 0.5 part of modified polycarboxylate, and 88.4 parts of mineral powder filler.

[0065] The premixed masterbatch 2 is premixed by the following materials in parts by weight, specifically 15 parts of hydroxyethyl methyl cellulose ether (HEMC), 2.5 parts of etherified starch, 20 parts of bentonite, 5 parts of polyalkylene oxide block copolymer, 0.5 parts of α-olefin sulfonate, 1 part of modified polycarboxylate, and 56 parts of mineral powder filler.

[0066] The method for preparing the premixed masterbatch comprises the following preparation steps:

[0067] S1. Weighing cellulose ether, etherified starch, bentonite, polyalkylene oxide block copolymer, α-olefin sulfonate, modified polycarboxylate and mineral powder filler in proportion;

[0068] S2. Add the weighed raw materials into a small mixer and stir for 15 to 30 minutes. Take out 10 portions of the premix and add them into the mixer again and stir for 5 to 10 minutes to prepare a premix masterbatch.

[0069] Table 1 Composition by weight of easily dispersible, highly workable lightweight plaster gypsum slurry

[0070]

[0071] The physical properties of the lightweight plastering gypsum material in the above-mentioned embodiment are tested according to the method specified in GB / T 28627-2012 "Plastering Gypsum" standard, and the results are shown in Table 2 below.

[0072] Table 2 Test results

[0073]

[0074]

[0075] The test results of the embodiments and comparative examples in Table 2 show that the bulk density and volume density of the lightweight plaster gypsum material prepared by the present invention after adding a large amount of lightweight aggregate are both less than 1000 kg / m 3 , the mechanical properties meet the standard requirements. Compared with the comparative example, the premixed masterbatch in the embodiment formula contains polyalkylene oxide block copolymer, α-olefin sulfonate and modified polycarboxylate components, which improves the specific surface area of ​​the mixing water and enhances the wettability of the mixing water to the lightweight plaster gypsum dry powder, so that the lightweight plaster gypsum material of the present invention is easy to stir evenly after adding water, and there is no agglomeration in the slurry, and the slurry after stirring contains a proper amount of pores with uniform pore size. These evenly distributed pores together with gypsum cementitious materials, lightweight aggregates, fillers, etc. constitute a hardened body structure after the lightweight plaster gypsum solidifies and hardens. Although the flexural compressive strength test results of the embodiment are lower than those of the comparative example, under the premise of meeting the standard requirements, the "compression-flexural ratio" of the embodiment is lower than that of the comparative example, which reflects to a certain extent that the lightweight plaster gypsum material of the embodiment of the present invention has better flexibility. It is well known that in the building wall leveling layer material, the flexibility of the covering layer material from the base wall to the finishing layer is required to be higher than that of the base material. Such a structural combination can reduce the generation of wall cracks to a certain extent. In addition, compared with other leveling mortar materials, under the condition of equivalent mechanical properties, the lightweight plaster gypsum material prepared by the present invention exhibits the characteristics of "lightweight and high strength", which can reduce the building load and improve the building's seismic fortification level in construction applications.

[0076] The light plastering gypsum material prepared by the present invention is prepared by modifying raw materials, optimizing the dosage of each raw material, and using technical means such as the hydration mechanism of gypsum cementitious materials and the action principle of premixed masterbatch. Tests show that the light plastering gypsum prepared by the present invention is easy to quickly disperse evenly when mixed with water, has no agglomerates in the slurry, has good slurry workability, and has high construction efficiency.

[0077] To sum up, the embodiments of the present invention are only preferred examples of the present invention and do not limit the present invention in any form. Any equivalent changes made by technicians familiar with the profession without departing from the scope of the technical solution of the present invention using the disclosed technical content are regarded as equivalent examples of the present invention. At the same time, any equivalent changes, modifications and evolutions made to the above embodiments based on the essential technology of the present invention are still within the protection scope of the technical solution of the present invention.

[0078] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0079] The experimental methods without specific conditions in the present invention are usually carried out under conventional conditions or conditions recommended by the manufacturer.

[0080] Unless otherwise stated, the various optimization technical solutions in the present invention can be combined with each other.

[0081] Unless otherwise indicated, percentages and parts are by weight.

[0082] Experimental methods without specific conditions specified in the instructions and examples are usually carried out under conventional conditions or conditions recommended by the manufacturers.

[0083] Unless otherwise defined, all professional and scientific terms used herein have the same meaning as those familiar to those skilled in the art. In addition, any method and material similar or equivalent to the described content can be applied to the method of the present invention.

Claims

1. An easily dispersible, highly workable and lightweight plastering gypsum material, characterized in that: It includes the following components in parts by weight: 50.0-95.0 parts of building gypsum powder, 0.5-10.0 parts of reaction activity regulator, 0-30.0 parts of volcanic ash active material, 0.5-40.0 parts of mineral powder filler, 3.0-15.0 parts of expanded lightweight aggregate, 0.05-0.2 parts of setting time regulator, and 2.0 parts of premixed masterbatch; The premixed masterbatch comprises the following components in parts by weight: 5.0-20.0 parts of cellulose ether, 1.0-5.0 parts of etherified starch, 0-40.0 parts of bentonite, 2.5-10.0 parts of polyalkylene oxide block copolymer, 0.1-1.0 parts of α-olefin sulfonate, 0.5-2.5 parts of modified polycarboxylate, and 21.5-91.0 parts of mineral powder filler.

2. The easily dispersible, highly workable and lightweight plastering gypsum material according to claim 1 is characterized in that: It includes one or more of the following features: The building gypsum powder is any one of natural gypsum, desulfurized gypsum, phosphogypsum or a mixture of several calcined gypsum powder, the calcination temperature range is 140-220°C, the initial setting time is ≥3min, the final setting time is ≤30min, the chloride ion content is ≤900ppm, the specific surface area is 500-900㎡ / kg, the anhydrous phase AⅢ content is ≤5.0%, the semi-aqueous phase content is ≥75%, and the dihydrate phase content is ≤4.0%; The reaction activity regulator is one or a mixture of slaked lime, silicate cement, sulphoaluminate cement and aluminium sulfate; The volcanic ash active material is one or a mixture of fly ash from power plants, ground blast furnace slag powder, silica ash, and high-altitude land; The mineral powder filler is one or a mixture of limestone powder, dolomite powder and talcum powder, and the fineness is 200-400 mesh; The cellulose ether is one or a mixture of hydroxyethyl methyl cellulose HEMC and hydroxypropyl methyl cellulose HPMC; The etherified starch is made from natural polysaccharides and is highly etherified and modified. The bentonite is sodium bentonite with a specific surface area of ​​15 to 25 m 2 / g; The polyalkylene oxide block copolymer is a surfactant of a nonionic polyalkylene oxide block copolymer; The α-olefin sulfonate is sodium α-olefin sulfonate; The modified polycarboxylate is a modified polycarboxylic acid high-efficiency water reducing agent.

3. The easily dispersible, highly workable and lightweight plastering gypsum material according to claim 1 is characterized in that: The expanded lightweight aggregate is closed-cell expanded perlite baked in a gas furnace or an electric furnace; and / or The closed-cell expanded perlite has a main particle size distribution of 20 mesh to 120 mesh; and / or The closed-cell expanded perlite has a loose bulk density of 80 to 120 kg / m 3 .

4. The easily dispersible, highly workable and lightweight plastering gypsum material according to claim 1 is characterized in that: The setting time regulator is: Calcium sulfate, added with one or more of modified amino acid salts, citric acid and its salts, tartaric acid and its salts, boric acid and its salts, phosphates; and / or The calcium sulfate is calcium sulfate dihydrate powder with a specific surface area of ​​6000 to 9000 m2 / kg; and / or The calcium sulfate dihydrate powder is one or a mixture of ultra-finely ground natural dihydrate gypsum, desulfurized gypsum and phosphogypsum.

5. The easily dispersible, highly workable and lightweight plastering gypsum material according to claim 1 is characterized in that: The method for preparing the premixed masterbatch comprises the following preparation steps: S1. Weigh cellulose ether, etherified starch, bentonite, polyalkylene oxide block copolymer, α-olefin sulfonate, modified polycarboxylate in proportion, and balance to 100 parts with mineral powder filler; S2. Add the weighed raw materials into a small mixer and stir for 15 to 30 minutes. Take out 10 portions of the premix and add them into the mixer again and stir for 5 to 10 minutes to prepare a premix masterbatch.

6. A method for preparing the easily dispersible, highly workable and lightweight plastering gypsum material according to claim 1, characterized in that: It comprises the following preparation steps: S1. The building gypsum powder, the reactive regulator, the volcanic ash active material, the mineral powder filler, the setting time regulator and the premixed masterbatch are respectively metered and transported to the mixer for high-speed mixing; S2. The expanded lightweight aggregate is metered into a mixer and mixed evenly to prepare a lightweight plaster gypsum material that is easily dispersed and highly workable.

7. An easily dispersible, highly workable, lightweight plastering gypsum slurry prepared by using the easily dispersible, highly workable, lightweight plastering gypsum material according to any one of claims 1 to 6, characterized in that: The invention is mainly prepared by mixing the easily dispersible, highly workable and lightweight plastering gypsum material and water, and the weight ratio thereof is (1.2-2.5):1.

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