Phosphogypsum-based building material and preparation method and application thereof

Abstract

The application belongs to the technical field of engineering materials, and provides a phosphogypsum-based building material and a preparation method and application thereof, which is prepared from raw materials containing the following components in parts by mass: carbonized medical slag 100-200 parts, sodium oleate 5-8 parts, aggregate 40-50 parts, coupling agent 20-30 parts, phosphogypsum 350-450 parts, hexadecyl trimethoxysilane 40-60 parts, cement 30-35 parts, and water 80-90 parts. The phosphogypsum and carbonized medical slag are comprehensively utilized, the medical slag contains a large amount of microporous structure after carbonization, and the medical slag is modified by sodium oleate to graft a large amount of groups; the phosphogypsum and hexadecyl trimethoxysilane are mixed and treated to connect the organic groups on the surface of the phosphogypsum to the maximum extent; and the medical slag and the phosphogypsum are tightly and firmly combined together through the group combination mode, so that the material looseness is fundamentally avoided, and the compressive strength and the thermal insulation performance of the material are improved.

Description

Technical Field

[0001] This invention relates to the field of engineering materials technology, and in particular to a phosphogypsum-based building material, its preparation method, and its application. Background Technology

[0002] Phosphogypsum is an industrial byproduct, primarily a solid waste generated during the production of phosphate fertilizers or the processing of phosphate rock. Its main component is calcium sulfate. As a solid waste, phosphogypsum can only be disposed of through stockpiling. This method not only occupies large amounts of land but also generates significant amounts of leachate that pollutes the soil under the influence of rainwater. This necessitates substantial investment in the treatment of both the phosphogypsum and the resulting wastewater, significantly increasing production costs and environmental pressure. Furthermore, with the accelerating pace of modern life, the annual stockpiled amount of phosphogypsum is gradually increasing. Therefore, how to rationally utilize phosphogypsum to reduce production costs and environmental impact has become an urgent problem to be solved. Summary of the Invention

[0003] The purpose of this invention is to overcome the deficiencies in the prior art and provide a phosphogypsum-based building material, its preparation method, and its application.

[0004] To achieve the above-mentioned objectives, the present invention provides the following technical solution:

[0005] This invention provides a phosphogypsum-based building material, prepared from raw materials comprising the following parts by weight:

[0006] 100-200 parts carbonized drug residue, 5-8 parts sodium oleate, 40-50 parts aggregate, 20-30 parts coupling agent, 350-450 parts phosphogypsum, 40-60 parts hexadecyltrimethoxysilane, 30-35 parts cement, and 80-90 parts water.

[0007] Preferably, the carbonized medicinal residue has a particle size of 600-800 mesh.

[0008] Preferably, the aggregate has a particle size ≤ 0.3 mm;

[0009] The aggregate comprises coal gasification slag and quartz sand; the mass ratio of the coal gasification slag to quartz sand is 1 to 2:1.

[0010] Preferably, the fineness of the phosphogypsum is 200-400 mesh.

[0011] The present invention also provides a method for preparing the phosphogypsum-based building material, comprising the following steps:

[0012] (1) The modified carbonized drug residue is obtained by mixing carbonized drug residue, sodium oleate and water in the first part;

[0013] (2) The aggregate and coupling agent are mixed to obtain the treated aggregate;

[0014] (3) Phosphogypsum and hexadecyltrimethoxysilane are mixed to obtain modified phosphogypsum;

[0015] (4) Mix the modified carbonized drug residue, treated aggregate, modified phosphogypsum and the remaining raw materials to obtain the phosphogypsum-based building material.

[0016] Preferably, the ultrasonic power of the mixture in step (1) is 150-200W and the time is 15-25min;

[0017] In step (1), the mass of the first portion of water is 40-50% of the total water mass.

[0018] Preferably, the mixing speed in step (2) is 200-300 rpm and the time is 30-40 min.

[0019] Preferably, the mixing power in step (3) is 150-200W, the time is 10-20min, and the temperature is 40-50℃.

[0020] Preferably, the mixing speed in step (4) is 1500-2000 rpm and the time is 10-15 min.

[0021] The present invention also provides the application of the phosphogypsum-based building material in thermal insulation materials.

[0022] This invention provides a phosphogypsum-based building material, prepared from raw materials comprising the following parts by weight: 100-200 parts carbonized medicinal residue, 5-8 parts sodium oleate, 40-50 parts aggregate, 20-30 parts coupling agent, 350-450 parts phosphogypsum, 40-60 parts hexadecyltrimethoxysilane, 30-35 parts cement, and 80-90 parts water. This invention utilizes a combined approach of solid waste utilization, integrating phosphogypsum and carbonized medicinal residue, thus avoiding the large-scale accumulation of the residue. After carbonization, the residue contains a large number of microporous structures. Modification with sodium oleate allows for the grafting of numerous inorganic and organic groups. The mixing of phosphogypsum and hexadecyltrimethoxysilane maximizes the attachment of organic groups to the phosphogypsum surface. The residue and phosphogypsum are tightly and firmly bonded together through group bonding, fundamentally preventing material loosening and improving the material's compressive strength and thermal insulation performance. Moreover, due to the presence of aggregates, some aggregates can enter the micropores of carbonized medicinal residues, enhancing the compressive strength of the modified residues and expanding the application range of composite materials.

[0023] This invention utilizes solid waste to treat large quantities of accumulated phosphogypsum, thereby increasing industrial value and showing broad application prospects. Detailed Implementation

[0024] This invention provides a phosphogypsum-based building material, prepared from raw materials comprising the following parts by weight:

[0025] 100-200 parts carbonized drug residue, 5-8 parts sodium oleate, 40-50 parts aggregate, 20-30 parts coupling agent, 350-450 parts phosphogypsum, 40-60 parts hexadecyltrimethoxysilane, 30-35 parts cement, and 80-90 parts water.

[0026] In this invention, the mass fraction of the carbonized medicinal residue is preferably 120-180 parts, more preferably 130-170 parts, and even more preferably 140-160 parts.

[0027] In this invention, the sodium oleate is preferably 5.5 to 7.5 parts by mass, more preferably 5.6 to 7.4 parts by mass, and even more preferably 6 to 7 parts by mass.

[0028] In this invention, the mass fraction of the aggregate is preferably 42 to 48 parts, more preferably 43 to 47 parts, and even more preferably 44 to 46 parts.

[0029] In this invention, the coupling agent is preferably 22 to 28 parts by mass, more preferably 23 to 27 parts by mass, and even more preferably 25 to 26 parts by mass.

[0030] In this invention, the preferred mass fraction of the phosphogypsum is 360-440 parts, more preferably 380-420 parts, and even more preferably 390-410 parts.

[0031] In this invention, the mass fraction of the hexadecyltrimethoxysilane is preferably 42 to 58 parts, more preferably 44 to 56 parts, and even more preferably 48 to 52 parts.

[0032] In this invention, the cement is preferably 31 to 34 parts by mass, more preferably 32 to 33 parts by mass, and even more preferably 32.4 to 32.5 parts by mass.

[0033] In this invention, the water is preferably 82 to 88 parts by mass, more preferably 83 to 87 parts, and even more preferably 84 to 85 parts by mass.

[0034] In this invention, the particle size of the carbonized medicinal residue is preferably 600-800 mesh, more preferably 650-750 mesh, and even more preferably 680-720 mesh.

[0035] In this invention, the collected medicinal residue is washed in water. The preferred mass ratio of medicinal residue to water is 1:6-8, more preferably 1:6.5-7.5, and even more preferably 1:6.6-7. The ultrasonic power for washing is preferably 1000-1200W, more preferably 1050-1150W, and even more preferably 1080-1120W. The preferred time is 30-60 min, more preferably 40-50 min, and even more preferably 45-48 min. After washing, the residue is dried to constant weight and then carbonized. The preferred carbonization temperature is 200-300℃, more preferably 220-280℃, and even more preferably 240-260℃. The preferred time is 2.5-4.5 h, more preferably 3-4 h, and even more preferably 3.5-3.8 h. The preferred liquid-to-solid ratio is 10-20:1, more preferably 12-18:1, and even more preferably 14-16:1. After carbonization, the residue is filtered and separated to obtain the carbonized medicinal residue.

[0036] In this invention, the particle size of the aggregate is preferably ≤0.3mm, more preferably ≤0.2mm, and even more preferably ≤0.1mm.

[0037] In this invention, the aggregate comprises coal gasification slag and quartz sand; the mass ratio of the coal gasification slag to quartz sand is preferably 1 to 2:1, more preferably 1.2 to 1.8:1, and even more preferably 1.4 to 1.6:1.

[0038] In this invention, the coupling agent is preferably KH550 and / or KH560.

[0039] In this invention, the fineness of the phosphogypsum is preferably 200-400 mesh, more preferably 220-380 mesh, and even more preferably 260-340 mesh.

[0040] The present invention also provides a method for preparing the phosphogypsum-based building material, comprising the following steps:

[0041] (1) The modified carbonized drug residue is obtained by mixing carbonized drug residue, sodium oleate and water in the first part;

[0042] (2) The aggregate and coupling agent are mixed to obtain the treated aggregate;

[0043] (3) Phosphogypsum and hexadecyltrimethoxysilane are mixed to obtain modified phosphogypsum;

[0044] (4) Mix the modified carbonized drug residue, treated aggregate, modified phosphogypsum and the remaining raw materials to obtain the phosphogypsum-based building material.

[0045] In this invention, the ultrasonic power of the mixture in step (1) is preferably 150-200W, more preferably 160-190W, and even more preferably 170-180W; the time is preferably 15-25min, more preferably 16-24min, and even more preferably 18-22min.

[0046] In this invention, the mass of the first portion of water in step (1) is preferably 40-50% of the water mass, more preferably 42-48%, and even more preferably 44-46%.

[0047] In this invention, the mixing speed in step (2) is preferably 200-300 rpm, more preferably 220-280 rpm, and even more preferably 240-260 rpm; the mixing time is preferably 30-40 min, more preferably 32-38 min, and even more preferably 34-36 min.

[0048] In this invention, the mixing power in step (3) is preferably 150-200W, more preferably 160-190W, and even more preferably 170-180W; the time is preferably 10-20min, more preferably 12-18min, and even more preferably 14-16min; the temperature is preferably 40-50℃, more preferably 42-48℃, and even more preferably 44-46℃.

[0049] In this invention, the mixing speed in step (4) is preferably 1500-2000 rpm, more preferably 1600-1900 rpm, and even more preferably 1700-1800 rpm; the mixing time is preferably 10-15 min, more preferably 11-14 min, and even more preferably 12-13 min.

[0050] The present invention also provides the application of the phosphogypsum-based building material in thermal insulation materials.

[0051] The technical solutions provided by the present invention will be described in detail below with reference to the embodiments, but they should not be construed as limiting the scope of protection of the present invention.

[0052] Example 1

[0053] The collected dregs were placed in water at a mass ratio of 1:7 and then washed at 1200W for 40 minutes. After washing, the dregs were dried to constant weight. The liquid-solid ratio was controlled at 15:1 and the dregs were carbonized at 240℃ for 4 hours. After carbonization, the carbonized dregs were obtained by filtration.

[0054] Take 150 parts of carbonized drug residue, 7 parts of sodium oleate, 45 parts of aggregate, 24 parts of coupling agent, 360 parts of phosphogypsum, 50 parts of hexadecyltrimethoxysilane, 34 parts of cement, and 85 parts of water. The carbonized drug residue has a particle size of 700 mesh, the aggregate particle size is ≤0.2 mm, and the mass ratio of coal gasification slag to quartz sand is 1:1. The phosphogypsum has a fineness of 300 mesh, the cement is silicate cement, and the coupling agent is KH550.

[0055] Carbonized drug residue, sodium oleate, and the first portion of water (40% of the total water mass) were mixed and stirred at 150W for 20 minutes to obtain modified carbonized drug residue. Aggregate and coupling agent were stirred at 250rpm for 30 minutes to obtain treated aggregate. Phosphogypsum and hexadecyltrimethoxysilane were mixed and stirred at 150W and 45℃ for 15 minutes to obtain modified phosphogypsum. Modified carbonized drug residue, treated aggregate, modified phosphogypsum, and the remaining raw materials were mixed and stirred at 1600rpm for 15 minutes to obtain phosphogypsum-based building materials.

[0056] Example 2

[0057] The collected dregs were placed in water at a mass ratio of 1:6 and then washed for 60 minutes at 1000W. After washing, the dregs were dried to constant weight. The liquid-solid ratio was controlled at 12:1, and the dregs were carbonized at 280℃ for 4.5 hours. After carbonization, the carbonized dregs were obtained by filtration.

[0058] The following ingredients were used: 120 parts carbonized drug residue, 6 parts sodium oleate, 42 parts aggregate, 27 parts coupling agent, 410 parts phosphogypsum, 48 parts hexadecyltrimethoxysilane, 31 parts cement, and 83 parts water. The carbonized drug residue had a particle size of 650 mesh, the aggregate particle size was ≤0.3 mm, and the mass ratio of coal gasification slag to quartz sand was 1.2:1. The phosphogypsum had a fineness of 400 mesh, the cement was silicate cement, and the coupling agent was KH560.

[0059] Carbonized drug residue, sodium oleate, and a first portion of water (50% of the total water mass) were mixed and stirred at 190W for 15 min to obtain modified carbonized drug residue. Aggregate and coupling agent were stirred at 240 rpm for 40 min to obtain treated aggregate. Phosphogypsum and hexadecyltrimethoxysilane were mixed and stirred at 190W and 40℃ for 10 min to obtain modified phosphogypsum. Modified carbonized drug residue, treated aggregate, modified phosphogypsum, and the remaining raw materials were mixed and stirred at 1700 rpm for 13 min to obtain phosphogypsum-based building materials.

[0060] Example 3

[0061] The collected dregs were placed in water at a mass ratio of 1:7.5 and then washed for 50 minutes at 1050W. After washing, the dregs were dried to constant weight. The liquid-solid ratio was controlled at 18:1 and the dregs were carbonized at 220℃ for 3 hours. After carbonization, the carbonized dregs were obtained by filtration.

[0062] The following ingredients were used: 160 parts carbonized drug residue, 5.6 parts sodium oleate, 44 parts aggregate, 27 parts coupling agent, 410 parts phosphogypsum, 42 parts hexadecyltrimethoxysilane, 31 parts cement, and 88 parts water. The carbonized drug residue had a particle size of 800 mesh, the aggregate particle size was ≤0.1 mm, the mass ratio of coal gasification slag to quartz sand was 2:1, the phosphogypsum had a fineness of 340 mesh, the cement was silicate cement, and the coupling agent was KH550.

[0063] Carbonized drug residue, sodium oleate, and the first portion of water (50% of the total water mass) were mixed and stirred at 190W for 24 min to obtain modified carbonized drug residue; aggregate and coupling agent were stirred at 300 rpm for 40 min to obtain treated aggregate; phosphogypsum and hexadecyltrimethoxysilane were mixed and stirred at 190W and 50℃ for 20 min to obtain modified phosphogypsum; modified carbonized drug residue, treated aggregate, modified phosphogypsum, and the remaining raw materials were mixed and stirred at 1900 rpm for 12 min to obtain phosphogypsum-based building materials.

[0064] The phosphogypsum-based building materials prepared in Examples 1-3 were subjected to performance testing. Samples of 100mm×100mm×100mm were prepared and tested on a flexural testing machine and a compressive testing machine, respectively. A flat plate thermal conductivity meter was used, with the hot plate initial temperature set at 30℃, the cold plate initial temperature set at 2℃, and the power set at 3W. The thermal conductivity was tested and the results are recorded in Table 1.

[0065] Table 1 Performance test results of phosphogypsum-based building materials

[0066]

[0067] As can be seen from the above embodiments, the present invention provides a phosphogypsum-based building material. This invention utilizes solid waste in combination, comprehensively utilizing phosphogypsum and carbonized medicinal residue, thus avoiding the large-scale accumulation of the residue. After carbonization, the medicinal residue contains a large number of microporous structures. Modification of the residue with sodium oleate allows for the grafting of numerous inorganic and organic groups. Mixing phosphogypsum with hexadecyltrimethoxysilane maximizes the attachment of organic groups to the phosphogypsum surface. The residue and phosphogypsum are tightly and firmly bonded together through group bonding, fundamentally preventing material loosening and improving the material's compressive strength and thermal insulation performance. Furthermore, due to the presence of aggregates, some aggregates can enter the micropores of the carbonized medicinal residue, enhancing the compressive strength of the modified residue and expanding the application range of the composite material. As can be seen from the results of the embodiments, the phosphogypsum-based building material provided by the present invention has a dry compressive strength of 283.43 N, a compressive strength of 61.2 MPa, and a thermal conductivity as low as 0.034 W / (m·k), making it a phosphogypsum-based composite material with excellent comprehensive performance.

[0068] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A phosphogypsum-based building material, characterized in that, It is prepared from raw materials comprising the following parts by mass: Carbonized drug residue 100-200 parts, sodium oleate 5-8 parts, aggregate 40-50 parts, coupling agent 20-30 parts, phosphogypsum 350-450 parts, hexadecyltrimethoxysilane 40-60 parts, cement 30-35 parts, water 80-90 parts; The preparation method of the phosphogypsum-based building material includes the following steps: (1) The modified carbonized drug residue is obtained by mixing carbonized drug residue, sodium oleate and water from the first part; (2) The aggregate and coupling agent are mixed to obtain the treated aggregate; (3) Mix phosphogypsum and hexadecyltrimethoxysilane to obtain modified phosphogypsum; (4) Mix the modified carbonized drug residue, treated aggregate, modified phosphogypsum and the remaining raw materials to obtain the phosphogypsum-based building material.

2. The phosphogypsum-based building material as described in claim 1, characterized in that, The particle size of the carbonized medicinal residue is 600-800 mesh.

3. The phosphogypsum-based building material as described in claim 1 or 2, characterized in that, The aggregate has a particle size ≤ 0.3 mm; The aggregate comprises coal gasification slag and quartz sand; the mass ratio of the coal gasification slag to the quartz sand is 1~2:

1.

4. The phosphogypsum-based building material as described in claim 3, characterized in that, The fineness of the phosphogypsum is 200-400 mesh.

5. A method for preparing the phosphogypsum-based building material according to any one of claims 1 to 4, characterized in that, Includes the following steps: (1) The modified carbonized drug residue is obtained by mixing carbonized drug residue, sodium oleate and water in the first part; (2) The aggregate and coupling agent are mixed to obtain the treated aggregate; (3) Mix phosphogypsum and hexadecyltrimethoxysilane to obtain modified phosphogypsum; (4) Mix the modified carbonized drug residue, treated aggregate, modified phosphogypsum and the remaining raw materials to obtain the phosphogypsum-based building material.

6. The preparation method according to claim 5, characterized in that, The ultrasonic power used in step (1) is 150~200W and the time is 15~25min; In step (1), the mass of the first portion of water is 40-50% of the total water mass.

7. The preparation method according to claim 5 or 6, characterized in that, The mixing speed in step (2) is 200~300 rpm and the time is 30~40 min.

8. The preparation method according to claim 7, characterized in that, The mixing power in step (3) is 150~200W, the time is 10~20min, and the temperature is 40~50℃.

9. The preparation method according to claim 5, characterized in that, The mixing speed in step (4) is 1500~2000 rpm and the time is 10~15 min.

10. The application of the phosphogypsum-based building material according to any one of claims 1 to 4 in thermal insulation materials.

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