Glass ceramic preparation process based on phosphogypsum and glass ceramic

Abstract

The invention provides a phosphogypsum-based microcrystalline glass preparation process and microcrystalline glass. The phosphogypsum-based glass ceramic preparation process comprises the following steps: raw material blending, high-temperature smelting, glass melt treatment and plate heat treatment, and after the heat treatment is completed, the plate is naturally cooled to room temperature to obtain the glass ceramic. Wherein the heat treatment comprises the following steps: in a temperature interval of 500-590 DEG C, carrying out heat preservation on the plate for 0.5-1 hour, and carrying out pretreatment; then, the temperature is increased to 600-790 DEG C, and nucleation heat treatment is conducted on the plate; and finally, performing crystallization heat treatment on the plate in a high-temperature environment of 800-950 DEG C. According to the method, the operation of desulfurization treatment on ardealite when the ardealite is conventionally utilized is omitted, and the technological process is simple; the ardealite is efficiently utilized, so that the obtained microcrystalline glass material is high in strength and extremely low in sulfur content, and the microcrystalline glass can be widely applied to building materials and other applications.

Description

Technical Field

[0001] This invention belongs to the field of solid waste recycling and application technology, specifically relating to a microcrystalline glass preparation process based on phosphogypsum and microcrystalline glass. Background Technology

[0002] Phosphogypsum is an industrial solid waste mainly generated during the production of phosphate fertilizers. In industrial production, approximately four to five tons of phosphogypsum are produced for every ton of phosphoric acid produced, resulting in extremely large emissions. With the continuous development of the phosphate chemical industry, the accumulation of phosphogypsum is constantly increasing, becoming an environmental problem that urgently needs to be addressed.

[0003] Currently, there are two main methods for industrially treating phosphogypsum: stockpiling and comprehensive utilization. Stockpiling is a traditional and common practice, but it occupies a large amount of land, and phosphogypsum contains soluble and harmful components. Long-term stockpiling poses a risk of leakage, which can pollute soil and water sources, damage the ecosystem, and harm animals, plants, and human health. For comprehensive utilization, phosphogypsum can be used in building material production (such as gypsum board and cement retarder) and agricultural soil improvement. However, pretreatment is required to remove harmful substances, especially sulfur. The removal process is complex, increases costs, and limits the scope and efficiency of utilization. Furthermore, existing methods have limited capacity and are difficult to process large quantities of phosphogypsum. In addition, improper treatment can lead to sulfur pollution of the atmosphere as sulfur-containing waste gas.

[0004] Meanwhile, as a novel material with excellent properties, microcrystalline glass has broad application prospects in construction, decoration, electronics, and other fields. However, in existing microcrystalline glass production processes, factors such as fluctuations in raw material composition and insufficient precision in heat treatment process control often lead to unstable quality of the produced microcrystalline glass, resulting in large performance differences and numerous defects, which seriously affects the promotion and application of microcrystalline glass. How to efficiently and safely process and utilize phosphogypsum, reduce its negative environmental impact, and at the same time improve the production quality and stability of microcrystalline glass is currently an urgent problem to be solved. Summary of the Invention

[0005] Aiming to solve the technical problem of how to efficiently and safely process and utilize phosphogypsum in the aforementioned commonly used technologies, reduce its negative environmental impact, and improve the production quality and stability of glass-ceramics, this invention provides a phosphogypsum-based glass-ceramic preparation process, including the following steps:

[0006] Raw material preparation: Prepare mixed raw materials according to the following mass percentages: phosphogypsum 10%-50%, quartz sand 30%-60%, soda ash 4%-10%, sodium fluorosilicate 4%-10%, feldspar 5%-30%, borax 0%-5%, calcite 0%-20%, and defoamer 1%-5%.

[0007] High-temperature smelting: The mixed raw materials are placed in a high-temperature furnace for smelting to generate low-impurity glass melt and sulfur-containing waste gas;

[0008] Glass melt processing: The cooled low-impurity glass melt is formed into sheets through a molding process;

[0009] Heat treatment of the sheet material: The sheet material is pretreated by holding it at a temperature range of 500-590℃ for 0.5-1 hour; then, the temperature is raised to 600-790℃ and the sheet material is subjected to nucleation heat treatment for 1-3 hours; finally, the sheet material is subjected to crystallization heat treatment at a high temperature of 800-950℃ for 1-3 hours to form a uniform microcrystalline structure.

[0010] After the heat treatment is completed, allow the plate to cool naturally to room temperature to obtain microcrystalline glass.

[0011] Furthermore, the defoamer accounts for 1.2%-4.6% of the mass of the mixed raw materials.

[0012] Furthermore, the defoamer comprises antimony powder and NaNO3;

[0013] The antimony powder constitutes 0.2%-0.6% of the mass of the mixed raw materials, and the sodium nitrate constitutes 1%-4% of the mass of the mixed raw materials.

[0014] Furthermore, the temperature of the smelting process is controlled at 1400-1600℃, and the duration is 480-500 min.

[0015] Furthermore, the pretreatment temperature is 500-550℃; the nucleation heat treatment temperature is 600-750℃.

[0016] Furthermore, the treatment of the sulfur-containing waste gas includes the following steps: treating the sulfur-containing waste gas with ammonia water in stages to obtain crude ammonium sulfate product.

[0017] Furthermore, the ammonia water segmented spray treatment includes a dilute ammonia water pre-spray treatment and a concentrated ammonia water post-spray treatment.

[0018] The concentration of the dilute ammonia solution is 5%-10%; the concentration of the concentrated ammonia solution is 15%-25%.

[0019] Furthermore, obtaining the cooled low-impurity glass melt includes the step of: slowly cooling the low-impurity glass melt to 1050-1150°C.

[0020] Furthermore, the forming process includes calendering.

[0021] This invention provides a microcrystalline glass, prepared by the microcrystalline glass preparation process based on phosphogypsum as described in any one of the above claims.

[0022] Compared with the prior art, the present invention has at least the following advantages:

[0023] This invention provides a process for preparing glass-ceramics based on phosphogypsum. In the raw material preparation step, phosphogypsum is explicitly designated as a key raw material, prepared as a mixed raw material at a mass percentage of 10%-50%. By introducing phosphogypsum into the glass-ceramics preparation process, a new approach is provided for the large-scale utilization of phosphogypsum. This increases the dosage of phosphogypsum in glass-ceramics production, achieves high-value utilization of phosphogypsum, reduces dependence on other raw materials, minimizes environmental pollution caused by phosphogypsum accumulation, and solves the problems of low utilization rate, high cost, and limited comprehensive utilization scope of traditional treatment methods.

[0024] This invention provides a process for preparing microcrystalline glass based on phosphogypsum. In the heat treatment steps of the sheet material, the temperature range and time of pretreatment, nucleation heat treatment, and crystallization heat treatment are precisely controlled. Pretreatment is carried out at 500-590℃ for 0.5-1 hour to create stable conditions for subsequent treatments; nucleation heat treatment at 600-790℃ lasts for 1-3 hours to promote the formation of crystal nuclei within the sheet material; crystallization heat treatment at 800-950℃ is held for 1-3 hours to allow the crystal nuclei to grow and form a uniform microcrystalline structure. By precisely controlling the heat treatment process parameters, the produced microcrystalline glass is ensured to have a uniform microcrystalline structure and stable physical and chemical properties, improving product quality and reliability and solving the problem of unstable microcrystalline glass quality in existing production processes. Attached Figure Description

[0025] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0026] Figure 1 This is a physical image of the microcrystalline glass plate prepared in Embodiment 1 of the present invention;

[0027] Figure 2 This is a physical image of the microcrystalline glass plate prepared in Embodiment 2 of the present invention;

[0028] Figure 3 This is a physical image of the microcrystalline glass plate prepared in Embodiment 3 of the present invention;

[0029] Figure 4 This is a physical image of the microcrystalline glass plate prepared in Embodiment 4 of the present invention;

[0030] Figure 5 This is a physical image of the microcrystalline glass plate prepared in Comparative Example 1 of the present invention;

[0031] Figure 6 This is a physical image of the microcrystalline glass plate prepared in Comparative Example 2 of the present invention;

[0032] Figure 7 This is a physical image of the microcrystalline glass plate prepared in Comparative Example 3 of the present invention;

[0033] Figure 8 This is a physical image of the microcrystalline glass plate prepared in Comparative Example 4 of the present invention. Detailed Implementation

[0034] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0035] Furthermore, the technical solutions of the various embodiments of the present invention can be combined with each other, but only if they are based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed by the present invention.

[0036] When numerical ranges are given in the embodiments, it should be understood that, unless otherwise stated in the present invention, both endpoints of each numerical range and any value between the two endpoints may be selected. Unless otherwise defined, all technical and scientific terms used in this invention, as well as the prior art known to those skilled in the art and the description of the invention, may be implemented using any prior art methods, devices, and materials similar to or equivalent to the methods, devices, and materials in the embodiments of the present invention.

[0037] This invention provides a process for preparing microcrystalline glass based on phosphogypsum, comprising the following steps:

[0038] S1. Raw material preparation: Prepare mixed raw materials according to the following mass percentages: phosphogypsum 10%-50%, quartz sand 30%-60%, soda ash 4%-10%, sodium fluorosilicate 4%-10%, feldspar 5%-30%, borax 0%-5%, calcite 0%-20%, and defoamer 1%-5%.

[0039] In some embodiments, the mixed raw materials may include the following components by mass fraction: 10%-50% phosphogypsum, 30%-60% quartz sand, 4%-10% soda ash, 4%-10% sodium fluorosilicate, 5%-30% feldspar, and 1%-5% defoamer.

[0040] In some specific embodiments, the mixed raw materials may include the following components by mass fraction: 30%-50% phosphogypsum, 30%-60% quartz sand, 4%-10% soda ash, 4%-10% sodium fluorosilicate, 5%-20% feldspar, and 1%-5% defoamer.

[0041] In some embodiments of the present invention, the mass percentage of the defoamer in the mixed raw materials is controlled to be 1.2%-4.6%.

[0042] In some embodiments of the present invention, the defoamer comprises antimony powder and NaNO3. In some more specific embodiments, the defoamer comprises 0.2%-0.6% antimony powder and 1%-4% sodium nitrate, based on the mass percentage of the mixed raw materials.

[0043] S2. High-temperature smelting: The mixed raw materials are placed in a high-temperature furnace for smelting to generate low-impurity glass melt and sulfur-containing waste gas.

[0044] In some embodiments of the present invention, the temperature of the smelting process is controlled to be 1400-1600°C and the duration is 480-500 min.

[0045] In some embodiments of the present invention, the treatment of the sulfur-containing waste gas includes the steps of: treating the sulfur-containing waste gas with ammonia water in stages to obtain crude ammonium sulfate product; in some more specific embodiments, the ammonia water staged spray treatment includes a dilute ammonia water pre-stage spray treatment and a concentrated ammonia water post-stage spray treatment.

[0046] The concentration of the dilute ammonia solution is 5%-10%; the concentration of the concentrated ammonia solution is 15%-25%.

[0047] After sulfur-containing waste gas is generated during the high-temperature smelting process, a segmented spray treatment process of ammonia water is used to convert sulfur into crude ammonium sulfate, which reduces environmental pollution while realizing the recovery and utilization of sulfur, improves the comprehensive utilization rate of resources, and solves the problem of sulfur-containing waste gas polluting the environment.

[0048] S3. Glass melt treatment: The cooled low-impurity glass melt is formed into a sheet through a molding process.

[0049] In some embodiments of the present invention, obtaining the cooled low-impurity glass melt includes the step of: slowly cooling the low-impurity glass melt to 1050-1150°C.

[0050] In some embodiments of the present invention, the forming process includes calendering.

[0051] In some embodiments of the present invention, the heating rate during the glass melt treatment process is 1-10℃ / min. If the heating rate is too low, the efficiency is too low; if the heating rate is too high, the temperature difference between the surface and the interior of the plate will increase, which will lead to inconsistent crystallization and even surface melting deformation.

[0052] S4. Heat treatment of the plate: The plate is pretreated by holding it at a temperature range of 500-590℃ for 0.5-1 hours; then, the temperature is raised to 600-790℃ and the plate is subjected to nucleation heat treatment for 1-3 hours; finally, the plate is subjected to crystallization heat treatment at a high temperature of 800-950℃ for 1-3 hours to form a uniform microcrystalline structure.

[0053] In some embodiments of the present invention, the pretreatment temperature is 500-550°C; the nucleation heat treatment temperature is 600-750°C.

[0054] S5. After the heat treatment is completed, allow the plate to cool naturally to room temperature to obtain microcrystalline glass.

[0055] The present invention also provides a microcrystalline glass, which is prepared by the microcrystalline glass preparation process based on phosphogypsum as described in any one of the above claims.

[0056] To facilitate a further understanding of the present invention by those skilled in the art, the following examples are provided:

[0057] Example 1

[0058] S1. Raw material preparation: Prepare mixed raw materials according to the following mass percentages: phosphogypsum 40%, quartz sand 30%, soda ash 7%, sodium fluorosilicate 8%, feldspar 10%, defoamer 4.6% (antimony powder 0.6%, NaNO3 4%), totaling 2 tons.

[0059] S2. High-temperature melting: The components in the above composition are mixed and then fed into a glass furnace in batches for melting to obtain low-impurity glass melt and sulfur-containing waste gas; in this embodiment, the melting temperature is 1500℃ and the melting time is 480min; the generated sulfur-containing waste gas is passed into a desulfurization device containing two-stage spray components, 5% dilute ammonia water is added to the front spray component, and 15% concentrated ammonia water is added to the rear spray component; crude ammonium sulfate product can be obtained.

[0060] S3. Glass melt treatment: The low-impurity glass melt is slowly cooled to 1150°C at a rate of 3°C / min, and then rolled into a sheet by a rolling mill.

[0061] S4. Heat treatment of the sheet material: The obtained sheet material is sent to a heat treatment kiln and pretreated at 500°C for 1 hour. Then, nucleation heat treatment is performed, in which the sheet material obtained by the forming process is nucleated at 650°C for 1.5 hours. Finally, crystallization heat treatment is performed on the sheet material at 850°C for 2 hours.

[0062] S5. Cool to room temperature to obtain the microcrystalline glass plate.

[0063] In this embodiment, please refer to the physical image of the microcrystalline glass plate. Figure 1 As can be seen, the microcrystalline glass panel is smooth and free of obvious defects. Performance testing revealed that the microcrystalline glass panel has a bending strength of 126 MPa, far exceeding the national building materials standard of 30 MPa.

[0064] Example 2

[0065] S1. Raw material preparation: Prepare mixed raw materials according to the following mass percentages: phosphogypsum 35%, quartz sand 35%, soda ash 7%, sodium fluorosilicate 7%, feldspar 13%, defoamer 3% (antimony powder 0.5%, NaNO3 2.5%), totaling 2 tons.

[0066] S2. High-temperature melting: The components in the above composition are mixed and then fed into a glass furnace in batches for melting to obtain low-impurity glass melt and sulfur-containing flue gas. In this embodiment, the melting temperature is 1500℃ and the melting time is 500min. The generated sulfur-containing flue gas is passed into a desulfurization device containing two-stage spray components. 5% dilute ammonia water is added to the first spray component, and 15% concentrated ammonia water is added to the second spray component to obtain crude ammonium sulfate product.

[0067] S3. Glass melt treatment: The low-impurity glass melt is slowly cooled to 1100℃ at a rate of 5℃ / min, and then rolled into a sheet by a rolling mill.

[0068] S4. Heat treatment of the sheet material: The obtained sheet material is sent into a heat treatment kiln and pretreated by holding it at 500°C for 1 hour in the kiln; then nucleation heat treatment is performed by nucleating the sheet material obtained by the forming process at 650°C for 1.5 hours; finally, crystallization heat treatment is performed at 850°C for 2 hours.

[0069] S5. Cool to room temperature to obtain the microcrystalline glass plate.

[0070] In this embodiment, please refer to the physical image of the microcrystalline glass plate. Figure 2 As can be seen, the microcrystalline glass panel is smooth and free of obvious defects. Performance testing revealed that the microcrystalline glass panel has a bending strength of 117 MPa, far exceeding the national building materials standard of 30 MPa.

[0071] Example 3

[0072] S1. Raw material preparation: Prepare mixed raw materials according to the following mass percentages: phosphogypsum 20%, quartz sand 50%, soda ash 6%, sodium fluorosilicate 6%, feldspar 14%, defoamer 4% (antimony powder 0.8%, NaNO3 3.2%), totaling 2 tons.

[0073] S2. High-temperature melting: The components in the above composition are mixed and then fed into a glass furnace in batches for melting to obtain low-impurity glass melt and sulfur-containing flue gas; in this embodiment, the melting temperature is 1490℃ and the melting time is 490min. The generated sulfur-containing flue gas is passed into a desulfurization device containing two-stage spray components. 5% dilute ammonia water is added to the first spray component; 15% concentrated ammonia water is added to the second spray component; crude ammonium sulfate product can be obtained.

[0074] S3. Glass melt treatment: The low-impurity glass melt is slowly cooled to 1130°C at a rate of 3°C / min, and then rolled into a sheet by a rolling mill.

[0075] S4. Heat treatment of the sheet material: The obtained sheet material is sent into a heat treatment kiln and pretreated at 500°C for 1 hour. Then, nucleation heat treatment is performed, in which the sheet material obtained by the forming process is nucleated at 650°C for 2 hours. Finally, crystallization treatment is performed at 800°C for 2 hours.

[0076] S5. Cool to room temperature to obtain the microcrystalline glass plate.

[0077] In this embodiment, please refer to the physical image of the microcrystalline glass plate. Figure 3 As can be seen, the microcrystalline glass panel is smooth and free of obvious defects. Performance testing revealed that the microcrystalline glass panel has a bending strength of 129 MPa, far exceeding the national building materials standard of 30 MPa.

[0078] Example 4

[0079] Compared to Example 1, all other conditions remain the same in this example, except that the pretreatment temperature is adjusted from 500°C to 590°C and the nucleation heat treatment temperature is adjusted from 650°C to 790°C.

[0080] S1. Raw material preparation: Prepare mixed raw materials according to the following mass percentages: phosphogypsum 40%, quartz sand 30%, soda ash 7%, sodium fluorosilicate 8%, feldspar 10%, defoamer 4.6% (antimony powder 0.6%, NaNO3 4%), totaling 2 tons.

[0081] S2. High-temperature melting: The components in the above composition are mixed and then fed into a glass furnace in batches for melting to obtain low-impurity glass melt and sulfur-containing waste gas; in this embodiment, the melting temperature is 1500℃ and the melting time is 480min; the generated sulfur-containing waste gas is passed into a desulfurization device containing two-stage spray components, 5% dilute ammonia water is added to the front spray component, and 15% concentrated ammonia water is added to the rear spray component; crude ammonium sulfate product can be obtained.

[0082] S3. Glass melt treatment: The low-impurity glass melt is slowly cooled to 1150°C at a rate of 3°C / min, and then rolled into a sheet by a rolling mill.

[0083] S4. Heat treatment of the sheet material: The obtained sheet material is sent to a heat treatment kiln and pretreated at 590°C for 1 hour. Then, nucleation heat treatment is performed, in which the sheet material obtained by the forming process is nucleated at 690°C for 1.5 hours. Finally, crystallization heat treatment is performed on the sheet material at 850°C for 2 hours.

[0084] S5. Cool to room temperature to obtain the microcrystalline glass plate.

[0085] In this embodiment, please refer to the physical image of the microcrystalline glass plate. Figure 4 As can be seen, the microcrystalline glass panel is smooth and without obvious defects. Performance testing revealed that the microcrystalline glass panel's bending strength reached 104 MPa, still far exceeding the national building materials standard of 30 MPa. However, its bending strength is slightly lower, likely due to a slightly higher nucleation treatment temperature, resulting in fewer precipitated micronuclei.

[0086] Comparative Example 1

[0087] Compared to Example 1, only the ingredients and the composition of the defoamer were changed, while the rest of the steps remained the same. That is, the mixed raw materials were prepared according to the following mass percentages: 60% phosphogypsum, 10% quartz sand, 7% soda ash, 8% sodium fluorosilicate, 10% feldspar, and 5% defoamer (1% antimony powder and 4% sodium nitrate), totaling 2 tons.

[0088] The resulting glass plate has a total mass of 1.2 tons.

[0089] See the actual image of the glass plate. Figure 5 It can be seen that the material of this glass plate is relatively... Figure 1 The microcrystalline glass panel contained obvious impurities such as spots and patterns. Performance tests were conducted on the panel, and its flexural strength reached 36 MPa, slightly exceeding the national building materials standard of 30 MPa.

[0090] Comparative Example 2

[0091] Compared to Example 1, only the melting temperature was changed; all other steps remained the same. That is, the melting temperature was 1300°C.

[0092] The product glass plate was obtained, and the total mass of the glass plate was 1.5 tons.

[0093] See the actual image of the glass plate. Figure 6 It can be seen that the material of this glass plate is relatively... Figure 1 The microcrystalline glass panel exhibits uneven structure. Performance tests revealed that its flexural strength reached 44 MPa, slightly exceeding the national building materials standard of 30 MPa.

[0094] Comparative Example 3

[0095] Compared to Example 1, all other conditions in this comparative example remain unchanged, except that the pretreatment temperature in step S4 is adjusted from 500°C to 600°C. That is:

[0096] S4. Heat treatment of the sheet material: The obtained sheet material is sent into a heat treatment kiln and pretreated by holding it at 600°C for 1 hour. Then, nucleation heat treatment is performed, which involves nucleating the sheet material obtained by the forming process at 650°C for 1.5 hours. Finally, crystallization heat treatment is performed on the sheet material at 850°C for 2 hours.

[0097] The product glass plate was obtained, and the total mass of the glass plate was 1.5 tons.

[0098] See the actual image of the glass plate. Figure 7 It can be seen that the material of this glass plate is relatively... Figure 1 The microcrystalline glass exhibits uneven structure. Performance tests revealed that the flexural strength of this microcrystalline glass plate was only 43 MPa.

[0099] Comparative Example 4

[0100] Compared to Example 1, all other conditions remain unchanged in this comparative example, except that the nucleation heat treatment temperature in step S4 is adjusted from 650°C to 800°C. That is:

[0101] S4. Heat treatment of the sheet material: The obtained sheet material is sent to a heat treatment kiln and pretreated at 500°C for 1 hour. Then, nucleation heat treatment is performed, in which the sheet material obtained by the forming process is nucleated at 800°C for 1.5 hours. Finally, crystallization heat treatment is performed on the sheet material at 850°C for 2 hours.

[0102] The product glass plate was obtained, and the total mass of the glass plate was 1.5 tons.

[0103] See the actual image of the glass plate. Figure 8 It can be seen that the material of this glass plate is relatively... Figure 1The crystallization was uneven. Performance tests on the microcrystalline glass plate showed that its flexural strength was only 38 MPa.

[0104] The above technical solutions of the present invention are merely preferred embodiments of the present invention and do not limit the patent scope of the present invention. All equivalent structural transformations made under the technical concept of the present invention using the contents of the present invention specification and drawings, or direct / indirect applications in other related technical fields, are included in the patent protection scope of the present invention.

Claims

1. A process for the preparation of phosphogypsum-based microcrystalline glass, characterized by, The method comprises the steps of: Raw material preparation: prepare mixed raw materials in the following mass percentages: phosphogypsum 10%-50%, quartz sand 30%-60%, soda ash 4%-10%, sodium fluorosilicate 4%-10%, feldspar 5%-30%, borax 0%-5%, calcite 0%-20%, and defoaming agent 1%-5%; High-temperature smelting: place the mixed raw materials in a high-temperature smelting furnace for smelting treatment to generate a low-impurity glass melt and a sulfur-containing waste gas; Glass melt treatment: the cooled low-impurity glass melt is subjected to forming treatment to form a plate; Plate heat treatment: pre-treat the plate at a temperature of 500-590℃ for 0.5-1 hours; then, raise the temperature to 600-790℃, and subject the plate to nucleation heat treatment for 1-3 hours; finally, subject the plate to crystallization heat treatment at a high temperature of 800-950℃ for 1-3 hours to form a uniform microcrystalline structure; After the heat treatment is completed, allow the plate to cool naturally to room temperature to obtain the microcrystalline glass.

2. The phosphogypsum-based glass-ceramic production process according to claim 1, characterized in that, The mass percentage of the defoaming agent in the mixed raw materials is 1.2%-4.6%.

3. The phosphogypsum-based glass-ceramic production process according to claim 2, characterized in that, The composition of the defoaming agent comprises antimony powder and NaNO3. The mass percentage of the antimony powder in the mixed raw materials is 0.2%-0.6%, and the mass percentage of the sodium nitrate in the mixed raw materials is 1%-4%.

4. The phosphogypsum-based glass-ceramic production process according to claim 1, characterized in that, The temperature of the smelting treatment is controlled to be 1400-1600℃, and the time length is 480-500 minutes.

5. The phosphogypsum-based glass-ceramic production process according to claim 1, characterized in that, The temperature of the pre-treatment is 500-550℃, and the temperature of the nucleation heat treatment is 600-750℃.

6. The phosphogypsum-based glass-ceramic production process according to claim 1, characterized in that, The treatment of the sulfur-containing waste gas comprises the steps of: treating the sulfur-containing waste gas by using ammonia water in stages to obtain a crude ammonium sulfate product.

7. The phosphogypsum-based glass-ceramic production process according to claim 6, characterized in that, The ammonia water treatment in stages comprises a dilute ammonia water front-stage spraying treatment and a concentrated ammonia water rear-stage spraying treatment. The concentration of the dilute ammonia water is 5%-10%, and the concentration of the concentrated ammonia water is 15%-25%.

8. The phosphogypsum-based glass-ceramic production process according to claim 1, characterized in that, The acquisition of the cooled low-impurity glass melt comprises the step of: slowly cooling the low-impurity glass melt to 1050-1150℃.

9. The phosphogypsum-based glass-ceramic production process according to claim 1, characterized in that, The forming treatment comprises calendering treatment.

10. A microcrystalline glass characterized by, The microcrystalline glass based on phosphogypsum is prepared by the preparation process according to any one of claims 1-9.

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