Artificial aggregate based on desert sand and preparation method thereof
By adding internal and surface reinforcement materials to desert sand, artificial aggregates with excellent performance are prepared, which solves the problems of low density and insufficient strength in the existing technology, effectively utilize resources and reduce costs, and expands the scope of application.
Patent Information
- Application Number
- CN202510517442.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-23
- Publication Date
- 2025-07-08
AI Technical Summary
The existing artificial aggregate has low density and strength, high water absorption rate, which cannot meet the application in a wide range of scenarios, and the shortage of natural aggregate resources leads to increased costs and ecological damage.
Desert sand is used as the main matrix material, and artificial aggregates are prepared to improve their performance by co-strengthening of internal reinforcement materials (silica fume, lignin fiber, sodium silicate and CaO) and surface reinforcement materials (fly ash-cement mixed slurry).
Successfully prepared artificial aggregates with good performance, which can replace traditional natural sand and gravel aggregates, reduce production costs, expand the scope of engineering application, and realize resource utilization in desert areas.
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Figure CN120271307A_ABST
Abstract
Description
Technical Field
[0001] The present invention belongs to the technical field of building materials, and particularly relates to an artificial aggregate based on desert sand and a preparation method thereof. Background Art
[0002] Concrete is the largest volume of building materials in the world today. Among them, coarse aggregate is an important component of concrete, and its volume fraction is as high as 30% - 50%. At present, under the conditions of environmental protection requirements and resource scarcity, the raw materials of natural aggregates are seriously short of supply or even exhausted, resulting in the destruction of ecology and sustainability and a sharp increase in the cost of concrete. There is an urgent need to find a product that can replace natural aggregates.
[0003] As a substitute for natural aggregates, artificial aggregates are an excellent building material and have been widely used in the construction field in China. The concrete made from them has good volume stability and workability. Artificial aggregates are an industrial product obtained by processing powdery waste. However, currently, the density and strength of artificial aggregates are generally low, and the water absorption rate is also high, which cannot meet the application requirements in a wide range of scenarios. Desert sand, as a rich natural resource, is widely distributed and has a huge reserve. However, due to its fine particles and smooth surface, desert sand is usually not suitable for directly being used as the aggregate of concrete. Summary of the Invention
[0004] In order to solve the above problems, the purpose of the present invention is to provide an artificial aggregate based on desert sand and a preparation method thereof. Using desert sand as the main matrix material of the artificial aggregate, through internal and surface layer co-strengthening, the performance of the desert sand artificial aggregate is improved, which can replace traditional natural sand and gravel aggregates, realize the utilization of resources in desert areas, not only reduce the production cost of artificial aggregates, but also expand the engineering application scope of artificial aggregates.
[0005] In order to achieve the above technical purpose, the present invention adopts the following technical solutions:
[0006] A preparation method of an artificial aggregate based on desert sand, comprising the following steps:
[0007] (1) Mix desert sand, a binder and an internal strengthening material to obtain a mixture; perform granulation treatment on the mixture, and obtain aggregate particles after standard curing;
[0008] The internal strengthening material is composed of silica fume, lignin fiber, sodium silicate and CaO;
[0009] (2) Mix the aggregate particles with a surface layer strengthening material, and obtain artificial aggregates after carbonization curing and standard curing;
[0010] The surface layer strengthening material is a fly ash - cement mixed slurry.
[0011] Further, in step (1), the particle size of the desert sand is 0.070 - 0.695 mm.
[0012] Further, in step (1), the binder is ordinary Portland cement of PO42.5.
[0013] Further, in step (1), by weight, the dosage of desert sand is 70 - 80 parts, the dosage of binder is 20 - 25 parts; based on the binder, the dosage of silica fume is 3 - 8 wt%, the dosage of lignin fiber is 0.8 - 1.5 wt%, the dosage of sodium silicate is 0.5 - 0.8 wt%, and the dosage of CaO is 2 - 2.5 wt%.
[0014] Further, in step (1), the specific process of granulation treatment is: batch - feed the mixture into a disk granulator for granulation, and spray water during the granulation process. The total water consumption accounts for 10 - 15 wt% of the mass of the mixture;
[0015] The disk inclination angle of the disk granulator is 40 - 50°, and the rotation speed is 40 - 55 rpm;
[0016] The instrument for spraying water is a manual pneumatic high - pressure atomizing sprayer;
[0017] The duration of granulation treatment is 9 - 15 min.
[0018] Further, in step (1), the conditions for standard curing are: the temperature is 17 - 23 °C, and the humidity is above 90%.
[0019] Further, in step (2), the mass ratio of fly ash to cement in the fly ash - cement slurry is 10 - 15%:85 - 90%, and the water - binder ratio of the slurry is 0.35 - 0.45.
[0020] Further, in step (2), the conditions for carbonation curing are: the CO2 concentration is 20 ± 2%, the relative humidity is 70 ± 5%, and the temperature is 20 ± 2%; the conditions for standard curing are: the temperature is 17 - 23 °C, and the humidity is above 90%.
[0021] The present invention also provides artificial aggregates prepared by the above - mentioned preparation method.
[0022] Compared with the prior art, the present invention has the following beneficial effects:
[0023] The present invention uses desert sand as the main matrix material of artificial aggregate. Through internal and surface strengthening, desert sand with a particle size of 0.070 - 0.695 mm is successfully prepared into artificial aggregate with good performance for the first time. It can replace traditional natural sand and gravel aggregate, avoid over-exploitation of natural aggregate, processing and long-distance transportation of solid waste, realize resource utilization in desert areas, reduce the production cost of artificial aggregate, expand the engineering application range of artificial aggregate, and can be widely used in building materials such as concrete and mortar, with broad market application prospects. BRIEF DESCRIPTION OF THE DRAWINGS
[0024] Figure 1 It is a physical picture of the desert sand used in the present invention.
[0025] Figure 2 It is a physical picture of the artificial aggregate prepared in Example 1 of the present invention.
[0026] Figure 3 It is a process flow chart of the desert sand artificial aggregate in Example 1 of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS
[0027] The present invention will be further described below in conjunction with embodiments. It should be understood that these embodiments are only used to illustrate the present invention and not to limit the scope of the present invention. The experimental methods without specific conditions noted in the following embodiments are usually carried out according to conventional conditions or according to the conditions recommended by the manufacturer. In addition, unless otherwise defined, all professional and scientific terms used in the present invention have the same meaning as those familiar to skilled personnel in the field.
[0028] The reagents or raw materials used in the present invention can all be obtained through conventional channels. Unless otherwise specified, the reagents or raw materials used in the present invention are used in the conventional manner in the art or according to the product instructions. In addition, any methods and materials similar or equivalent to the described content can be applied to the method of the present invention. The preferred implementation methods and materials described in the present invention are only for demonstration purposes.
[0029] In the present invention, the conditions in the carbonation curing box are: CO2 concentration is 20 ± 2%, relative humidity is 70 ± 5%, and temperature is 20 ± 2%; the conditions in the standard curing box are: temperature is 17 - 23 °C, and humidity is above 90%.
[0030] Example 1
[0031] Components (parts by weight): 75 parts of desert sand, 22.85 parts of ordinary Portland cement of PO42.5, 1.25 parts of silica fume, 0.25 part of lignin fiber, 0.15 part of sodium silicate, 0.5 part of CaO, and 12 parts of water.
[0032] Preparation method:
[0033] (1) Weigh 1125 g of desert sand, 343 g of ordinary Portland cement, 19 g of silica fume, 4 g of lignin fiber, 2 g of sodium silicate, 7 g of CaO, and 180 g of water for granulation;
[0034] (2) Put the desert sand, ordinary Portland cement, silica fume, lignin fiber, sodium silicate, and CaO into a mixer and stir evenly to obtain a mixture;
[0035] (3) Put 700 g of the mixture into a disk granulator and moisten it in advance with a sprayer;
[0036] (4) Adjust the inclination angle of the disk granulator to 45° and the rotation speed to 40 rpm, and start the disk granulator;
[0037] (5) After running for 5 minutes, continue to slowly put in the remaining mixture, and at the same time continue to spray water. When there is 100 g of the mixture left, stop spraying water. Slowly add the last remaining mixture to wrap the wet surface of the aggregate. After continuing to rotate for 2 minutes, turn off the disk granulator. The duration of the granulation process is 12 min;
[0038] (6) Place the aggregate obtained by granulation at room temperature for 24 h, and then put it into a standard curing room for curing to 7 d to obtain aggregate particles;
[0039] (7) Immerse the aggregate particles in a fly ash - cement slurry (the mass ratio of fly ash to cement is 15:85, and the water - binder ratio of the slurry is 0.4), stir evenly and wait for 30 min, then take them out, place them at room temperature for 24 h, and then put them into a carbonation curing box for curing to 7 d to obtain complete aggregates;
[0040] (8) Put the complete aggregates into a standard curing room and cure them to 28 d to obtain artificial desert sand aggregates.
[0041] According to the test, the results are shown in Table 1. The single - particle compressive strength of the artificial desert sand aggregates obtained in this example reaches 8.94 MPa; the cylinder compressive strength reaches 5.6 MPa; the 24 - h water absorption rate is 2.67%; the apparent density is 2.32 g / cm 3 .
[0042] Comparative Example 1
[0043] Components (parts by weight): 75 parts of desert sand, 25 parts of ordinary Portland cement, and 12 parts of water.
[0044] Preparation method:
[0045] (1) Weigh 1125 g of desert sand, 375 g of ordinary Portland cement, and 180 g of water for granulation;
[0046] (2) Put the desert sand and ordinary Portland cement into a mixer and stir evenly to obtain a mixture;
[0047] (3) Put 700 g of the mixture into a disk granulator and moisten it in advance with a sprinkling can.
[0048] (4) Adjust the inclination angle of the disk granulator to 45° and the rotation speed to 40 rpm, and start the disk granulator.
[0049] (5) After running for 5 minutes, continue to slowly put in the remaining mixture while continuing to spray water. When there is 100 g of the mixture left, stop spraying water, slowly add the last remaining mixture to wrap the moist surface of the aggregate, continue to rotate for 2 minutes, then turn off the disk granulator. The duration of the granulation process is 12 min.
[0050] (6) Place the aggregate particles obtained by granulation at room temperature for 24 h, and then put them into a standard curing room for curing until 28 d to obtain artificial aggregates.
[0051] According to the test, the results are shown in Table 1. The single-particle compressive strength of the artificial aggregates of desert sand obtained in this comparative example reaches 5.40 MPa; the cylinder compressive strength reaches 4.3 MPa; the 24-h water absorption rate is 3.89%; the apparent density is 2.47 g / cm 3 .
[0052] Comparative Example 2
[0053] Components (parts by weight): 75 parts of desert sand, 22.85 parts of ordinary Portland cement, 1.25 parts of silica fume, 0.25 part of lignin fiber, 0.15 part of sodium silicate, 0.5 part of CaO, and 12 parts of water.
[0054] Preparation method:
[0055] (1) Weigh 1125 g of desert sand, 343 g of ordinary Portland cement, 19 g of silica fume, 4 g of lignin fiber, 2 g of sodium silicate, 7 g of CaO, and 180 g of water for granulation.
[0056] (2) Put the desert sand, ordinary Portland cement, silica fume, lignin fiber, sodium silicate, and CaO into a mixer and stir evenly to obtain a mixture.
[0057] (3) Put 700 g of the mixture into a disk granulator and moisten it in advance with a sprinkling can.
[0058] (4) Adjust the inclination angle of the disk granulator to 45° and the rotation speed to 40 rpm, and start the disk granulator.
[0059] (5) After running for 5 minutes, continue to slowly add the remaining mixture, while continuing to spray water. When the remaining mixture is 100 g, stop spraying water. Slowly add the last remaining mixture to wrap the wet surface of the aggregate, and continue to rotate for 2 minutes. Then, turn off the disc granulator. The duration of the granulation process is 12 min;
[0060] (6) Place the aggregate particles obtained by granulation at room temperature for 24 h, and then put them into the standard curing room for curing until 28 d to obtain artificial aggregates.
[0061] According to the test, the results are shown in Table 1. The single-particle compressive strength of the artificial aggregates of desert sand obtained in this comparative example reaches 6.59 MPa; the cylinder compressive strength reaches 4.7 MPa; the 24-h water absorption rate is 3.42%; the apparent density is 2.38 g / cm 3 .
[0062] Comparative Example 3
[0063] Components (parts by weight): 75 parts of desert sand, 25 parts of ordinary Portland cement, and 12 parts of water.
[0064] Preparation method:
[0065] (1) Weigh 1125 g of desert sand, 375 g of ordinary Portland cement, and 180 g of water for granulation;
[0066] (2) Put the desert sand and ordinary Portland cement into a mixer and stir evenly to obtain a mixture;
[0067] (3) Put 700 g of the mixture into a disc granulator and wet it in advance with a spray bottle;
[0068] (4) Adjust the inclination angle of the disc granulator to 45° and the rotation speed to 45 rpm, and start the disc granulator;
[0069] (5) After running for 5 minutes, continue to slowly add the remaining mixture, while continuing to spray water. When the remaining mixture is 100 g, stop spraying water. Slowly add the last remaining mixture to wrap the wet surface of the aggregate, and continue to rotate for 2 minutes. Then, turn off the disc granulator. The duration of the granulation process is 12 min;
[0070] (6) Place the aggregate obtained by granulation at room temperature for 24 h, and then put it into the standard curing room for curing until 7 d to obtain aggregate particles;
[0071] (7) Immerse the aggregate particles in a fly ash-cement slurry (the mass ratio of fly ash to cement is 15:85, and the water-binder ratio of the slurry is 0.4), stir evenly and wait for 30 min, then take them out, place them at room temperature for 24 h, and then put them into a carbonation curing box for curing until 7 d to obtain complete aggregates;
[0072] (8) Put the complete aggregate into the standard curing room and cure it for 28 days to obtain artificial desert sand aggregate.
[0073] According to the test, the results are shown in Table 1. The single-particle compressive strength of the artificial desert sand aggregate obtained in this comparative example reaches 7.36 MPa; the cylinder compressive strength reaches 4.9 MPa; the 24-hour water absorption rate is 3.05%; the apparent density is 2.42 g / cm 3 .
[0074] Comparative Example 4
[0075] Components (parts by weight): 75 parts of desert sand, 23.1 parts of ordinary Portland cement of PO42.5, 1.25 parts of silica fume, 0.15 parts of sodium silicate, 0.5 parts of CaO and 12 parts of water.
[0076] Preparation method:
[0077] (1) Weigh 1125 g of desert sand, 346 g of ordinary Portland cement, 19 g of silica fume, 2 g of sodium silicate, 7 g of CaO, and 180 g of water for granulation;
[0078] (2) Put the desert sand, ordinary Portland cement, silica fume, sodium silicate and CaO into a mixer and stir evenly to obtain a mixture;
[0079] (3) Put 700 g of the mixture into a disk granulator and moisten it in advance with a sprayer;
[0080] (4) Adjust the inclination angle of the disk granulator to 45° and the rotation speed to 40 rpm, and start the disk granulator;
[0081] (5) After running for 5 minutes, continue to slowly put in the remaining mixture, and at the same time continue to spray water. When there is 100 g of the mixture left, stop spraying water, slowly add the last remaining mixture to wrap the wet surface of the aggregate, and continue to rotate for 2 minutes, then turn off the disk granulator. The duration of the granulation treatment is 12 min;
[0082] (6) After placing the granulated aggregate at room temperature for 24 h, put it into the standard curing room and cure it for 7 days to obtain aggregate particles;
[0083] (7) Immerse the aggregate particles in fly ash-cement slurry (the mass ratio of fly ash to cement is 15:85, and the water-binder ratio of the slurry is 0.4), stir evenly and wait for 30 min, then take them out, place them at room temperature for 24 h, and then put them into a carbonation curing box and cure them for 7 days to obtain complete aggregate;
[0084] (8) Put the complete aggregate into the standard curing room and cure it for 28 days to obtain artificial desert sand aggregate.
[0085] According to the detection, the results are shown in Table 1. The single-particle compressive strength of the artificial desert sand aggregate obtained in this example reaches 8.5 MPa; the cylinder compressive strength reaches 5.0 MPa; the 24-hour water absorption rate is 2.70%; the apparent density is 2.29 g / cm 3 .
[0086] Comparative Example 5
[0087] Components (parts by weight): 75 parts of desert sand, 23 parts of ordinary Portland cement of PO42.5, 1.25 parts of silica fume, 0.25 part of lignin fiber, 0.5 part of CaO and 12 parts of water.
[0088] Preparation method:
[0089] (1) Weigh 1125 g of desert sand, 345 g of ordinary Portland cement, 19 g of silica fume, 4 g of lignin fiber, 7 g of CaO, and 180 g of water for granulation;
[0090] (2) Put the desert sand, ordinary Portland cement, silica fume, lignin fiber and CaO into a mixer and stir evenly to obtain a mixture;
[0091] (3) Put 700 g of the mixture into a disk granulator and moisten it in advance with a sprayer;
[0092] (4) Adjust the inclination angle of the disk granulator to 45° and the rotation speed to 40 rpm, and start the disk granulator;
[0093] (5) After running for 5 minutes, continue to slowly put in the remaining mixture, and continue to spray water at the same time. When 100 g of the mixture remains, stop spraying water, slowly add the last remaining mixture to wrap the wet surface of the aggregate, continue to rotate for 2 minutes, then turn off the disk granulator, and the granulation treatment duration is 12 min;
[0094] (6) Place the granulated aggregate at room temperature for 24 h, and then put it into a standard curing room for curing to 7 d to obtain aggregate particles;
[0095] (7) Immerse the aggregate particles in a fly ash-cement slurry (the mass ratio of fly ash to cement is 15:85, and the water-binder ratio of the slurry is 0.4), stir evenly and wait for 30 min, then take them out, place them at room temperature for 24 h, and then put them into a carbonation curing box for curing to 7 d to obtain complete aggregates;
[0096] (8) Put the complete aggregates into a standard curing room and cure them to 28 d to obtain artificial desert sand aggregates.
[0097] According to the test, the results are shown in Table 1. The single-particle compressive strength of the artificial desert sand aggregate obtained in this example reaches 8.20 MPa; the cylinder compressive strength reaches 4.8 MPa; the 24-hour water absorption rate is 2.75%; the apparent density is 2.31 g / cm 3 .
[0098] Comparative Example 6
[0099] Components (parts by weight): 75 parts of desert sand, 22.85 parts of ordinary Portland cement of PO42.5, 1.25 parts of silica fume, 0.25 part of lignin fiber, 0.15 part of sodium silicate, 0.5 part of CaO, and 12 parts of water.
[0100] Preparation method:
[0101] (1) Weigh 1125 g of desert sand, 343 g of ordinary Portland cement, 19 g of silica fume, 4 g of lignin fiber, 2 g of sodium silicate, 7 g of CaO, and 180 g of water for granulation;
[0102] (2) Put the desert sand, ordinary Portland cement, silica fume, lignin fiber, sodium silicate, and CaO into a mixer and stir evenly to obtain a mixture;
[0103] (3) Put 700 g of the mixture into a disk granulator and moisten it in advance with a spray bottle;
[0104] (4) Adjust the inclination angle of the disk granulator to 45° and the rotation speed to 40 rpm, and start the disk granulator;
[0105] (5) After running for 5 minutes, continue to slowly put in the remaining mixture, and at the same time continue to spray water. When there is 100 g of the mixture left, stop spraying water. Slowly add the last remaining mixture to wrap the wet surface of the aggregate, and continue to rotate for 2 minutes, then turn off the disk granulator. The duration of the granulation process is 12 min;
[0106] (6) Place the granulated aggregate at room temperature for 24 h, and then put it into a standard curing room and cure it for 7 d to obtain aggregate particles;
[0107] (7) Immerse the aggregate particles in a fly ash-cement slurry (the mass ratio of fly ash to cement is 15:85, and the water-binder ratio of the slurry is 0.4), stir evenly and wait for 30 min, then take them out, place them at room temperature for 24 h, and then put them into a standard curing room and cure them to 28 d to obtain the artificial desert sand aggregate.
[0108] According to the test, the results are shown in Table 1. The single-particle compressive strength of the artificial desert sand aggregate obtained in this example reaches 7.60 MPa; the cylinder compressive strength reaches 4.9 MPa; the 24-hour water absorption rate is 3.00%; the apparent density is 2.35 g / cm 3 .
[0109] Table 1 Performance test results of Example 1 and Comparative Examples 1-6
[0110]
Claims
1. A preparation method of artificial aggregate based on desert sand, characterized in that, It includes the following steps: (1) Mix desert sand, a binder, and internal strengthening materials to obtain a mixture; granulate the mixture, and obtain aggregate particles after standard curing; The internal strengthening materials are composed of silica fume, lignin fiber, sodium silicate, and CaO; (2) Mix the aggregate particles with surface strengthening materials, and obtain artificial aggregates after carbonation curing and standard curing; The surface strengthening material is a fly ash - cement mixed slurry.
2. The preparation method according to claim 1, characterized in that, In step (1), the particle size of the desert sand is 0.070 - 0.695 mm.
3. The preparation method according to claim 1, characterized in that, In step (1), the binder is ordinary Portland cement of PO42.
5.
4. The preparation method according to claim 1, characterized in that, In step (1), by weight, the dosage of desert sand is 70 - 80 parts, the dosage of the binder is 20 - 25 parts; based on the binder, the dosage of silica fume is 3 - 8 wt%, the dosage of lignin fiber is 0.8 - 1.5 wt%, the dosage of sodium silicate is 0.5 - 0.8 wt%, and the dosage of CaO is 2 - 2.5 wt%.
5. The preparation method according to claim 1, characterized in that, In step (1), the specific process of granulation is: put the mixture into a disk granulator in batches for granulation, and spray water during the granulation process. The total water consumption accounts for 10 - 15 wt% of the mass of the mixture; The disk inclination angle of the disk granulator is 40 - 50°, and the rotation speed is 40 - 55 rpm; The instrument for spraying water is a manual pneumatic high - pressure atomizing sprayer; The duration of granulation is 9 - 15 min.
6. The preparation method according to claim 1, characterized in that, In step (1), the conditions for standard curing are: the temperature is 17 - 23 °C, and the humidity is above 90%.
7. The preparation method according to claim 1, characterized in that, In step (2), the mass ratio of fly ash to cement in the fly ash - cement mixed slurry is 10 - 15%:85 - 90%, and the water - binder ratio of the mixed slurry is 0.35 - 0.
45.
8. The preparation method according to claim 1, characterized in that, In step (2), the conditions for carbonation curing are: the CO2 concentration is 20 ± 2%, the relative humidity is 70 ± 5%, and the temperature is 20 ± 2%; the conditions for standard curing are: the temperature is 17 - 23 °C, and the humidity is above 90%.
9. Artificial aggregates prepared by the preparation method according to any one of claims 1 - 8.