Light phosphogypsum wallboard and preparation method thereof

Abstract

The invention relates to the technical field of ardealite resource utilization, in particular to a light-weight ardealite wallboard and a preparation method thereof.The light-weight ardealite wallboard is characterized in that an admixture and a foaming agent are selected and added, the dosage ratio of ardealite, glass fibers and water is controlled, the dosage of ardealite reaches 85% or above, and when the water-gypsum ratio (the mass ratio of water to ardealite) is smaller than or equal to 35%, the light-weight ardealite wallboard is prepared. The ardealite wallboard can be rapidly formed, has excellent compressive strength and good hanging performance, improves the quality of the ardealite wallboard, and increases the consumption of ardealite.

Description

Technical Field

[0001] The invention relates to the technical field of phosphogypsum resource utilization, and in particular to a lightweight phosphogypsum wallboard and a preparation method thereof. Background Art

[0002] Phosphogypsum is an industrial solid waste discharged from the wet phosphoric acid process, which mainly contains impurities such as fluoride, phosphorus pentoxide, and phosphate. The traditional way to deal with phosphogypsum is to pile it up, which not only occupies land and causes secondary environmental pollution, but also makes it difficult to effectively utilize phosphogypsum resources. Therefore, the resource utilization of phosphogypsum has become an effective research approach to dispose of phosphogypsum.

[0003] At present, the technology for resource utilization of phosphogypsum is mainly divided into: ① Chemically treating phosphogypsum to prepare chemical products such as cement, ammonium sulfate, potassium sulfate and ammonium chloride as a by-product; ② Applying phosphogypsum to agricultural fertilizer fields such as fertilizer production and soil improvement production; ③ Processing phosphogypsum to prepare building materials such as stucco gypsum, gypsum blocks, cement retarders, unburned bricks or gypsum boards. For example: Patent application number 202011281340.8 uses thermosetting molding technology to prepare phosphogypsum-diatom mud foam concrete filling modules, which are made of modified phosphogypsum, diatom mud, ordinary Portland cement, fly ash, foaming agent, high-efficiency water reducer, activator and water for composite foaming, to achieve sound insulation and noise reduction after being loaded into the outer shell. Another example: Patent No. 202210565240.0 uses cement, water, activated fly ash, quartz sand, silica fume, gypsum, polyurethane foam, fiber, polycarboxylic acid water reducer, and wood powder reinforcement material to prepare partition boards; when using activated fly ash, add acetic acid ammonium to distilled water to dissolve it, spray acetic acid ammonium solution into the fly ash and cement granulation process, and cure and heat treat the result; achieve improved noise reduction and absorption effect, improved impact resistance, and reduced weight. Another example: Patent No. 202210359095.0 uses phosphogypsum, calcium carbonate, adhesive, water reducer, alum, cementitious material, foaming agent, etc. to mix evenly to prepare gypsum core layer material; then use surface paper, bottom paper and gypsum core layer material to prepare paper-faced gypsum, making it lightweight, porous, heat-insulating and sound-insulating. Another example: Patent application number 202310865730.7 uses phosphogypsum, methyl cellulose, polycarboxylic acid water reducer, polyolefin fiber, retarder, foaming agent, thixotropic agent, crystal transfer agent, and water to prepare phosphogypsum lightweight wall panels, so that the wall panels have higher strength, good sound insulation and excellent fire resistance.

[0004] It can be seen that the use of phosphogypsum in the field of building materials for the preparation of products such as gypsum boards or gypsum wallboards has been widely studied; however, when using phosphogypsum as a raw material to prepare gypsum products, it is usually necessary to add a large amount of water (the mass percentage of water to phosphogypsum reaches more than 40%) to ensure that the hydration degree of the phosphogypsum is complete, so as to improve the water seepage and bulging phenomenon of the phosphogypsum products in the later stage, otherwise it will affect the use environment of the phosphogypsum products; however, with the increase in water consumption, not only the maintenance period of the phosphogypsum products is extended, the cost of producing phosphogypsum products is increased, but also the compressive strength, hanging force and softening coefficient of the phosphogypsum board are affected, resulting in the overall poor quality of the phosphogypsum board. Summary of the invention

[0005] Based on the above technical problems, the present invention provides a lightweight phosphogypsum wallboard and a preparation method thereof, which adopts phosphogypsum powder, water, foaming agent, admixture and glass fiber as raw materials, and is prepared by stirring and mixing with a variable frequency stirring device and then molding. The phosphogypsum wallboard is lightweight, has good sound insulation and noise reduction effects, good thermal insulation effects, good fire resistance, excellent hanging force and other excellent properties.

[0006] The specific technical solution is:

[0007] Lightweight phosphogypsum wallboard, the raw material components are, by mass, 500 parts of phosphogypsum, 125-175 parts of water, 0.4-0.8 parts of foaming agent, 0.05-0.1 parts of admixture, and 2-5 parts of glass fiber; the foaming agent is a composite of sodium dodecyl sulfate and attapulgite mixed in a mass ratio of 1:0.1-0.5; the admixture is a polycarboxylate water reducer and / or sodium methyl silicate.

[0008] By selecting additives and foaming agents, combined with the dosage ratio of phosphogypsum, glass fiber and water, the phosphogypsum dosage reaches more than 85%, and when the water-to-paste ratio (water-to-phosphogypsum mass ratio) is ≤35%, the phosphogypsum wallboard can be quickly formed, has excellent compressive strength, and has good hanging performance, thereby improving the quality of the phosphogypsum wallboard and increasing the phosphogypsum consumption. The phosphogypsum used in the invention is phosphogypsum powder obtained by drying the phosphogypsum discharged from the wet phosphoric acid process to constant weight and grinding it.

[0009] Preferably, the raw material components are 500 parts of phosphogypsum, 150 parts of water, 0.5 parts of foaming agent, 0.07 parts of additive, and 3 parts of glass fiber in parts by mass.

[0010] More preferably, the foaming agent is a composite material of sodium dodecyl sulfate and attapulgite mixed in a mass ratio of 1:0.2.

[0011] Preferably, the admixture is a mixture of polycarboxylate water reducer and sodium methyl silicate in a mass ratio of 1:0.1-0.7.

[0012] More preferably, the admixture is a mixture of polycarboxylate water reducer and sodium methyl silicate in a mass ratio of 1:0.5.

[0013] The second purpose of the invention is to provide a method for preparing the above-mentioned lightweight phosphogypsum wallboard, wherein the raw materials are mixed according to mass parts, stirred for 100-120 seconds, poured into a mold, leveled, demoulded, and naturally cured. The wallboard production process is simple and easy to operate.

[0014] Preferably, the stirring process lasts for 110 seconds.

[0015] In order to improve the hanging property of the phosphogypsum wallboard, preferably, the leveling is to put the mold on a vibration table, pour the mixed material into the mold, and use a scraper to level and vibrate for 10-20 seconds. More preferably, the frequency of the vibration is 5000-10000 times / min.

[0016] In order to enhance the waterproofness and self-cleaning properties, the paper-faced phosphogypsum wallboard is preferably embedded in the mold with a unit area mass of 190-230g / m 2 Waterproof paper.

[0017] Compared with the prior art, the technical effects created by the present invention are embodied in:

[0018] By using a proper proportion of phosphogypsum, admixtures, foaming agents, glass fibers and water, combined with the selection of specific foaming agents and specific composite admixtures, the amount of phosphogypsum incorporated is increased, the water-to-paste ratio (the mass ratio of water to phosphogypsum) is reduced, the amount of water added is reduced, and the compressive strength, hanging force, softening coefficient and other properties of the phosphogypsum wallboard are ensured to be better, the processing cycle of the phosphogypsum wallboard is shortened, and the preparation cost of the phosphogypsum wallboard is reduced.

[0019] The invention has a simple process flow and is easy to operate. DETAILED DESCRIPTION

[0020] In order to facilitate those skilled in the art to correctly understand the present invention and enable those skilled in the art to fully understand the technical content of the present invention, the technical solution of the present invention is further explained below in conjunction with specific implementation methods. However, this explanation does not limit the scope of protection required for the present invention. The scope of protection of the present invention by those skilled in the art cannot be limited to the following explanations. Any equivalent substitutions or changes made by any those skilled in the art or persons familiar with the technology in the art based on the present invention and the technical solution and inventive concept thereof should be covered within the scope of protection of the present invention.

[0021] In some embodiments, the raw material components of the lightweight phosphogypsum wallboard are 500 parts of phosphogypsum, 125-175 parts of water, 0.4-0.8 parts of foaming agent, 0.05-0.1 parts of admixture, and 2-5 parts of glass fiber in parts by mass; for example: 500 parts of phosphogypsum, 125 parts of water, 0.4 parts of foaming agent, 0.05 parts of admixture, and 2 parts of glass fiber; another example: 500 parts of phosphogypsum, 175 parts of water, 0.8 parts of foaming agent, 0.1 parts of admixture, and 5 parts of glass fiber; another example: 500 parts of phosphogypsum, parts, 150 parts of water, 0.5 parts of foaming agent, 0.07 parts of admixture, 3 parts of glass fiber; another example: 500 parts of phosphogypsum, 175 parts of water, 0.4 parts of foaming agent, 0.1 parts of admixture, 2 parts of glass fiber, etc.; the foaming agent is a composite material of sodium dodecyl sulfate and attapulgite in a mass ratio of 1:0.1-0.5, for example: 1:0.1, 1:0.2, 1:0.3, 1:0.4, 1:0.5, etc.; the admixture is polycarboxylate water reducer and / or sodium methyl silicate.

[0022] Phosphogypsum wallboards are prepared by using a foaming agent composed of specific raw materials and specific admixtures with phosphogypsum, glass fiber and water, avoiding the addition of other ingredients and increasing the amount of phosphogypsum added, which helps to speed up the disposal of stockpiled phosphogypsum and reduce the pollution of the environment caused by phosphogypsum. At the same time, the water-to-gypsum ratio (the mass ratio of water to phosphogypsum) is reduced, the amount of water added is reduced, the strength, softening coefficient, hanging force and other properties of the phosphogypsum wallboards are improved, the quality of the phosphogypsum wallboards is improved, the maintenance period of the phosphogypsum wallboards is shortened, and the efficiency of the phosphogypsum wallboards being formed and shipped out of the factory is accelerated.

[0023] In some embodiments, the admixture is a mixture of polycarboxylate water reducer and sodium methyl silicate in a mass ratio of 1:0.1-0.7, for example, 1:0.1, 1:0.2, 1:0.3, 1:0.4, 1:0.5, 1:0.6 or 1:0.7, etc. This helps to enhance the waterproofness of the phosphogypsum wallboard and extend its service life.

[0024] In some embodiments, the method for preparing the lightweight phosphogypsum wallboard comprises mixing the raw materials according to parts by mass, stirring for 100-120 seconds, for example, 100 seconds, 110 seconds, 120 seconds, etc., pouring into a mold, leveling, demolding, and naturally curing. The process is simple and easy to operate.

[0025] In some embodiments, the leveling is to place the mold on a vibration table, pour the mixed material into the mold, use a scraper to level and vibrate for 10-20 seconds, for example: 10 seconds, 15 seconds, 20 seconds, etc. to improve the hanging property and bending failure load resistance of the phosphogypsum wallboard.

[0026] In some embodiments, the frequency of the vibration is 5000-10000 times / min, for example, 5000 times / min, 6000 times / min, 7000 times / min, 8000 times / min, 9000 times / min, 10000 times / min, etc. Strengthening the strength of phosphogypsum wallboard.

[0027] In some embodiments, a mold is embedded with a unit area mass of 190-230 g / m 2 Waterproof paper. Enhance the surface waterproofness of phosphogypsum wallboard and enhance moisture resistance.

[0028] In order to explore the technical effects that the invention can bring, the researchers conducted the following experimental studies:

[0029] Example 1

[0030] 5000g of phosphogypsum, 1250g of water, 4g of foaming agent, 0.5g of admixture and 20g of glass fiber are mixed, stirred for 100s, poured into a mold and flattened into a 90mm thickness, demolded, and naturally cured to obtain a phosphogypsum wallboard; the foaming agent is a composite material of sodium dodecyl sulfate and attapulgite mixed in a mass ratio of 1:0.1; the admixture is a polycarboxylic acid water reducer.

[0031] Example 2

[0032] On the basis of Example 1, 5000 g of phosphogypsum, 1500 g of water, 5 g of foaming agent, 0.7 g of admixture and 30 g of glass fiber were mixed, and the rest were the same as Example 1.

[0033] Example 3

[0034] On the basis of Example 1, 5000 g of phosphogypsum, 1750 g of water, 7 g of foaming agent, 0.8 g of admixture and 40 g of glass fiber were mixed, and the rest were the same as in Example 1.

[0035] Example 4

[0036] On the basis of Example 1, 5000 g of phosphogypsum, 1750 g of water, 8 g of foaming agent, 0.9 g of admixture and 50 g of glass fiber were mixed, and the rest were the same as in Example 1.

[0037] Example 5

[0038] On the basis of Example 1, the foaming agent is a composite material formed by mixing sodium dodecyl sulfate and attapulgite in a mass ratio of 1:0.3, and the rest are the same as Example 1.

[0039] Example 6

[0040] On the basis of Example 1, the foaming agent is a composite material formed by mixing sodium dodecyl sulfate and attapulgite in a mass ratio of 1:0.5, and the rest is the same as Example 1.

[0041] Example 7

[0042] On the basis of Example 1, the foaming agent is a composite material formed by mixing sodium dodecyl sulfate and attapulgite in a mass ratio of 1:1, and the rest is the same as Example 1.

[0043] Example 8

[0044] On the basis of Example 1, an equal mass of attapulgite is used as the foaming agent instead of sodium dodecyl sulfate, and the rest is the same as Example 1.

[0045] Example 9

[0046] On the basis of Example 1, an equal mass of sodium dodecyl sulfate was used instead of attapulgite as the foaming agent, and the rest was the same as Example 1.

[0047] Example 10

[0048] On the basis of Example 1, an equal mass of sodium methyl silicate was used to replace the polycarboxylate water reducer, and the rest was the same as Example 1.

[0049] Embodiment 11

[0050] On the basis of Example 8, an equal mass of sodium methyl silicate was used to replace the polycarboxylate water reducer, and the rest was the same as Example 8.

[0051] Example 12

[0052] On the basis of Example 9, an equal mass of sodium methyl silicate was used to replace the polycarboxylate water reducer, and the rest was the same as Example 9.

[0053] Embodiment 13

[0054] On the basis of Example 1, the admixture is a mixture of polycarboxylate water-reducing agent and sodium methyl silicate in a mass ratio of 1:0.1, and the rest is the same as Example 1.

[0055] Embodiment 14

[0056] On the basis of Example 1, the admixture is a mixture of polycarboxylate water-reducing agent and sodium methyl silicate in a mass ratio of 1:0.5, and the rest is the same as Example 1.

[0057] Embodiment 15

[0058] On the basis of Example 1, the admixture is a mixture of polycarboxylate water-reducing agent and sodium methyl silicate in a mass ratio of 1:0.7, and the rest is the same as Example 1.

[0059] Example 16

[0060] On the basis of Example 1, the admixture is a mixture of polycarboxylate water-reducing agent and sodium methyl silicate in a mass ratio of 1:1, and the rest is the same as Example 1.

[0061] Embodiment 17

[0062] On the basis of Example 1, the leveling process is to place the mold on a vibration table, pour the mixed material into the mold, use a scraper to level it, and vibrate it at 5000 times / min for 10 seconds. The rest is the same as Example 1.

[0063] Test 1: Performance testing

[0064] The phosphogypsum wallboard samples prepared in Examples 1 to 17 were tested for impact resistance (A, times), bending failure load (B, times), compressive strength (C, MPa), softening coefficient (D), drying shrinkage value (E, mm / m), hanging force (F, N) and other properties according to GB / T23450-2009, airborne sound insulation (G, dB) according to GB / T19889-2005, fire resistance (H, h) according to GB / T9978.1-2008, and heat transfer coefficient (I, W / (m 2 ·K)); and record the test results in the following Table 1, where each set of data is tested ten times and the average value is taken.

[0065] Table 1

[0066]

[0067] Conclusion: ① From Examples 1 to 4, it can be seen that as the amount of water added increases, the water-to-cement ratio increases, and the impact resistance, compressive strength and hanging performance of the phosphogypsum wallboard all have a significant downward trend. ② From Examples 1 and 5 to 9, it can be seen that the relative amount of sodium dodecyl sulfate and attapulgite in the foaming agent will have a serious impact on the impact resistance and hanging force of the phosphogypsum wallboard, and it will be improved with the increase of the relative amount of attapulgite, and then deteriorate with the increase of the relative amount of attapulgite; moreover, the use of sodium dodecyl sulfate or attapulgite alone in the foaming agent will cause the impact resistance and hanging of the phosphogypsum wallboard to deteriorate. It can be seen that sodium dodecyl sulfate and attapulgite have a synergistic enhancement effect. ③ From Examples 1, 8, 9 and 10 to 12, it can be seen that the use of sodium methyl silicate instead of polycarboxylate water reducer as an admixture has little effect on the overall performance of the phosphogypsum wallboard. ④ From Example 1, Example 8 to Example 12 and Example 13 to Example 16, it can be seen that sodium methyl silicate and polycarboxylate water reducer mixed into an admixture will help enhance the impact resistance, bending failure load, compressive strength and hanging performance of the phosphogypsum wallboard, and the combined use of sodium methyl silicate and polycarboxylate water reducer will produce a synergistic enhancement effect on the mechanical properties of the phosphogypsum wallboard. ⑤ From Example 1 and Example 17, it can be seen that after vibration treatment, it will help to improve the compactness of the phosphogypsum wallboard and improve the noise reduction and hanging properties.

[0068] Test 2: Moisture resistance test

[0069] When the phosphogypsum wallboards of Example 1, Example 4, Example 8, Example 9, Example 10, Example 13 and Example 17 were prepared, the obtained phosphogypsum wallboards were placed in a room (constant temperature and humidity) with a humidity of 25% and a temperature of 28° C., and after being placed for 48 hours, the weight difference of the phosphogypsum wallboards was weighed and calculated, and the moisture absorption rate (%) of the phosphogypsum wallboards was calculated using the following formula:

[0070] Moisture absorption rate = {(mass after placement - mass before placement) ÷ mass before placement} × 100%

[0071] The calculation results are recorded in the following Table 2:

[0072] Table 2

[0073]

[0074] It can be seen that the addition of sodium methyl silicate as an admixture can effectively enhance the moisture resistance of the phosphogypsum wallboard. Other matters not covered by the invention can be achieved by conventional technical means with reference to the prior art or common knowledge known to those skilled in the art.

Claims

1. A lightweight phosphogypsum wallboard, characterized in that: The raw material components are 500 parts by mass of phosphogypsum, 125-175 parts of water, 0.4-0.8 parts of foaming agent, 0.05-0.1 parts of admixture, and 2-5 parts of glass fiber; the foaming agent is a composite of sodium dodecyl sulfate and attapulgite mixed in a mass ratio of 1:0.1-0.5; the admixture is a polycarboxylate water reducer and / or sodium methyl silicate.

2. The lightweight phosphogypsum wallboard according to claim 1, characterized in that: The raw material components are 500 parts of phosphogypsum, 150 parts of water, 0.5 parts of foaming agent, 0.07 parts of additive, and 3 parts of glass fiber in parts by mass.

3. The lightweight phosphogypsum wallboard according to claim 1, characterized in that: The foaming agent is a composite material of sodium dodecyl sulfate and attapulgite mixed in a mass ratio of 1:0.

2.

4. The lightweight phosphogypsum wallboard according to claim 1, characterized in that: The admixture is a mixture of polycarboxylate water reducer and sodium methyl silicate in a mass ratio of 1:0.1-0.

7.

5. The lightweight phosphogypsum wallboard according to claim 1, characterized in that: The admixture is a mixture of polycarboxylate water reducer and sodium methyl silicate in a mass ratio of 1:0.

5.

6. The method for preparing the lightweight phosphogypsum wallboard according to any one of claims 1 to 5, characterized in that: The raw materials are mixed according to the mass parts, stirred for 100-120s, poured into the mold, leveled, demoulded, and naturally cured.

7. The method for preparing the lightweight phosphogypsum wallboard according to claim 6, characterized in that: The stirring process was continued for 110 s.

8. The method for preparing the lightweight phosphogypsum wallboard according to claim 6, characterized in that: The leveling process is to place the mold on a vibration table, pour the mixed material into the mold, and use a scraper to level the material and vibrate for 10-20 seconds.

9. The method for preparing the lightweight phosphogypsum wallboard according to claim 8, characterized in that: The frequency of the vibration is 5000-10000 times / min.

10. The method for preparing the lightweight phosphogypsum wallboard according to claim 6 or 8, characterized in that: The mold is embedded with a unit area mass of 190-230g / m 2 Waterproof paper.

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