Non-autoclaved artificial aggregate and preparation method thereof

Abstract

The application provides a kind of artificial aggregate of steam-free curing and a preparation method thereof, the artificial aggregate includes mixture and water; the mixture includes the following components by mass percentage: cementitious material 15-85%, fly ash 0-65% and stone powder 10-85%; the amount of water is 10% to 30% of the total mass of the mixture. The application uses cement or gypsum and other cementitious materials, adds industrial by-products such as fly ash and stone powder to prepare coarse aggregate, mixes the cementitious material with fly ash and stone powder, granulates, and forms artificial aggregate with high structural strength after rotary solid particle and dry granular drying. The prepared coarse aggregate can replace traditional coarse aggregate such as stone, reduce the consumption of natural resources and reduce costs. Compared with traditional coarse aggregate, the artificial aggregate of the application has the advantages of no flaky and needle-shaped particles, zero mud content, high sphericity and easy construction.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of aggregate preparation, and particularly relates to a non-autoclaved artificial aggregate and a preparation method thereof. BACKGROUND

[0002] Aggregate with a particle size greater than 4.75 mm is called coarse aggregate, commonly known as stone. Commonly used are broken stone and pebble. Aggregate with a particle size less than 4.75 mm is called fine aggregate, commonly known as sand. Sand is divided into two categories according to the source: natural sand and artificial sand. Natural sand includes river sand, lake sand, mountain sand and desalination sea sand. Artificial sand is a general term for machine-made sand and mixed sand after soil removal. However, with the increasingly strict management of the exploitation of natural sandstone and other traditional natural coarse aggregates by the state policy, the price of natural sandstone continues to rise, and high-quality sandstone resources are even more scarce. At the same time, the state is increasingly strengthening the management of solid waste, and the demand gap for sandstone in the construction industry and other industries is becoming larger and larger. Therefore, the preparation of artificial aggregate to replace natural aggregate has become the main research content in the industry.

[0003] The commonly used artificial aggregate includes industrial waste, industrial by-products, construction waste (concrete), etc., such as shale ceramsite, clay ceramsite and other artificial lightweight aggregate, slag, natural coal gangue, fly ash ceramsite and other industrial waste lightweight aggregate. Among them, the aggregate prepared from construction waste has low cylinder compressive strength, poor firmness, uncontrollable needle-shaped and flaky particles, and needs to be calcined, which has a complex process and high preparation cost; the preparation method of shale ceramsite, clay ceramsite and other artificial lightweight aggregate also involves a sintering step, which has a complex process and high preparation cost.

[0004] Therefore, it is necessary to provide an improved technical solution to overcome the above-mentioned deficiencies of the prior art. SUMMARY

[0005] The purpose of the present application is to provide a non-autoclaved artificial aggregate and a preparation method thereof, to solve the problems of shortage of natural coarse aggregate and complex preparation process of existing artificial aggregate.

[0006] In order to achieve the above-mentioned purpose, the present application provides the following technical solutions:

[0007] The present application provides a non-autoclaved artificial aggregate, which comprises a mixture and water; the mixture comprises the following raw material components in mass percentage: cementitious material 15-85%, fly ash 0-65% and stone powder 10-85%; the amount of water is 10% to 30% of the total mass of the mixture.

[0008] Preferably, the artificial aggregate comprises a mixture and water; the mixture comprises the following raw material components in mass percentage: cementitious material 15-85%, fly ash 5-65% and stone powder 10-85%; the amount of water is 10% to 30% of the total mass of the mixture; the cementitious material is cement or building gypsum powder.

[0009] Preferably, when the cementitious material is cement, the mixture comprises the following raw material components in percentage by mass: cement 15-50%, fly ash 30-65% and stone powder 20-85%; the amount of water is 10% to 20% of the total mass of the mixture.

[0010] Preferably, when the cementitious material is building gypsum powder, the mixture comprises the following raw material components in percentage by mass: building gypsum powder 60-85%, fly ash 5-30% and stone powder 10-40%; the amount of water is 20% to 30% of the total mass of the mixture.

[0011] Preferably, when the cementitious material is building gypsum powder, the artificial aggregate further comprises a gypsum retarder, and the amount of the gypsum retarder is 0.1% to 0.4% of the mass of the building gypsum powder.

[0012] Preferably, the cement is ordinary Portland cement, which meets the performance requirements of P·O52.5 in GB 175-2007 "General Portland Cement";

[0013] The building gypsum powder meets the performance requirements of grade 4.0 in GB / T 9776-2022 "Building Gypsum";

[0014] The stone powder meets the lower limit performance requirements of GB / T 35164-2017 "Limestone Powder for Use in Cement, Mortar and Concrete";

[0015] The fly ash meets the performance requirements of grade I in GB / T 1596-2017 "Fly Ash for Use in Cement and Concrete";

[0016] The gypsum retarder is an amino acid type retarder or a protein type retarder.

[0017] The application provides a preparation method of the artificial aggregate for non-autoclaved curing, and the preparation method comprises the following steps:

[0018] Step 1, homogenization:

[0019] The raw materials and water are weighed according to the proportion and added into a mixer, the raw materials are uniformly stirred and then sent into a homogenization bin, and the raw materials are homogenized for 10-30 min, and the water content of the mixed raw materials after homogenization is 9% to 16%;

[0020] Step 2, granulation:

[0021] The mixed raw materials in the homogenization bin are sent into a granulator through conveying equipment, and the mixed raw materials are granulated, and after the granulation is completed, screening is performed to obtain a semi-finished product;

[0022] Step 3, solidification:

[0023] The semi-finished material is rotated in the rotary drum to reinforce the semi-finished material, i.e. the solid particle operation;

[0024] Step 4, drying:

[0025] The semi-finished material is sent to the granular area, and then is subjected to hot air drying and dry powder drying to obtain the mixed material with clear particles.

[0026] Step 5, screening:

[0027] The granular mixed material is screened and then packaged to obtain the artificial aggregate with different particle size ranges.

[0028] Preferably, in step 2, the material is atomized and added with water during the granulation, and the water spraying mode is intermittent, and the water spraying time is 5-10s.

[0029] Preferably, in step 2, the inclination angle of the granulation disc is 30-60°, the radius of the granulation disc is 1.8-2.0m, the rotation speed of the granulation disc is 20-30r / min, the granulation time is 4-6min, and the particle size of the semi-finished material is 5-20mm.

[0030] In step 3, the rotation speed of the rotary motion is 20-25r / min, the radius of the rotary drum is 0.6-0.8m, the solid particle time is 240-300s, and the forward moving speed of the semi-finished material is 0.5-1.0m / min.

[0031] Preferably, in step 4, the temperature of the hot air drying is 80-150℃, and the hot air drying time is 0.5-2min.

[0032] The dry powder drying adopts the spraying mode, the spraying speed is 40-60kg / min, and the spraying time is 0.5-2min.

[0033] The sprayed dry powder is any one or a mixture of multiple of cement powder, gypsum powder or fly ash powder.

[0034] Beneficial effects:

[0035] The present application uses cement or gypsum and other cementitious materials, adds industrial by-products such as fly ash and stone powder to prepare coarse aggregate, and the prepared coarse aggregate can replace traditional coarse aggregate such as stone, and compared with the traditional coarse aggregate, the artificial aggregate has the advantages of no flaky and needle-shaped particles, zero mud content, high sphericity, and convenient construction.

[0036] The artificial aggregate of the present application is formed by mixing cementing material and fly ash and stone powder, granulating, and drying the granulated material, and has high structural strength, and can be used to replace natural sand and gravel, reduce the consumption of natural resources, and reduce the cost.

[0037] The semi-finished product formed by granulation is subjected to rotary motion, which can improve the density and strength of the particles, and the particles have high sphericity and high molding rate after hot air drying and dry powder drying, and the artificial aggregate prepared has a cylinder compression strength of more than 4.0 MPa and a bulk density of not more than 1000 g / L, and the gypsum-based artificial aggregate has a cylinder compression strength of more than 3.0 MPa and a bulk density of not more than 700 g / L, which meets the use requirements.

[0038] The artificial aggregate can be combined with gypsum-based self-leveling for ground leveling, and the combined ground has better overall stability and is less likely to crack, and the artificial aggregate can be added to lightweight concrete, and the pumping capacity of the concrete is greatly improved due to the spherical shape of the artificial aggregate. BRIEF DESCRIPTION OF DRAWINGS

[0039] The drawings accompanying the specification of the present application serve to provide a further understanding of the present application, and the illustrative embodiments of the present application and their descriptions serve to explain the present application, and do not constitute an improper limitation on the present application. Among them:

[0040] Figure 1 The artificial aggregate obtained in Example 3 of the present application is shown in the figure. DETAILED DESCRIPTION

[0041] The technical solutions in the embodiments of the present application will be described clearly and completely below, and obviously, the described embodiments are only a part of the embodiments of the present application, but not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art belong to the scope of protection of the present application.

[0042] The present application will be described in detail below in combination with the embodiments. It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict.

[0043] The artificial aggregate provided by the application is prepared by mixing the mixture and water, wherein the mixture comprises cementitious material 15-85% (for example, 15%, 30%, 50%, 60%, 70%, 80% or 85%), fly ash 0-65% (for example, 0%, 5%, 10%, 20%, 30%, 35%, 50% or 65%) and stone powder 10-85% (for example, 10%, 20%, 35%, 50%, 70% or 85%) by mass percentage, and the water is used in an amount of 10%-30% (for example, 10%, 12.5%, 13%, 13.5%, 14%, 20% or 30%) of the total mass of the mixture.

[0044] If the cementitious material is continuously reduced below the lower limit of the above formula, the aggregate forming rate is low and the powder content is high (the forming rate is not more than 70%) under the same production process; if the cementitious material is continuously increased above the upper limit of the above formula, the aggregate is prone to clumping during the forming process, and the material cost of the aggregate is relatively high. Too little or too much water is not conducive to uniform mixing of the materials and granule forming during the granulation process.

[0045] In specific embodiments of the application, the artificial aggregate comprises a mixture and water, wherein the mixture comprises the following raw material components by mass percentage: cementitious material 15-85% (for example, 15%, 30%, 50%, 60%, 70%, 80% or 85%), fly ash 5-65% (for example, 5%, 10%, 20%, 30%, 35%, 50% or 65%) and stone powder 10-85% (for example, 10%, 20%, 35%, 50%, 70% or 85%); the water is used in an amount of 10%-30% (for example, 10%, 12.5%, 13%, 13.5%, 14%, 20% or 30%) of the total mass of the mixture; and the cementitious material is cement or building gypsum powder.

[0046] In specific embodiments of the application, when the cementitious material is cement, the mixture comprises the following raw material components by mass percentage: cement 15-50% (for example, 15%, 30% or 50%), fly ash 30-65% (for example, 30%, 35%, 50% or 65%) and stone powder 20-85% (for example, 20%, 35%, 50%, 70% or 85%); and the water is used in an amount of 10%-20% (for example, 10%, 12.5%, 13%, 13.5%, 14%, 17% or 20%) of the total mass of the mixture.

[0047] In specific embodiments of the present application, when the cementitious material is building gypsum powder, the mixture comprises the following raw material components in percentage by mass: building gypsum powder 60-85% (for example, 60%, 70%, 80%, or 85%), fly ash 5-30% (for example, 5%, 10%, 20%, or 30%), and stone powder 10-40% (for example, 10%, 20%, 30%, or 40%); and the amount of water is 20%-30% (for example, 20%, 24%, 25%, or 30%) of the total mass of the mixture.

[0048] In specific embodiments of the present application, when the cementitious material is building gypsum powder, the artificial aggregate further comprises a gypsum retarder, and the amount of the gypsum retarder is 0.1%-0.4% (for example, 0.1%, 0.18%, 0.2%, 0.3%, or 0.4%) of the mass of the building gypsum powder.

[0049] In specific embodiments of the present application,

[0050] The cement is ordinary portland cement, which meets the performance requirements of P·O52.5 in GB 175-2007 “General Portland Cement”;

[0051] The building gypsum powder meets the performance requirements of grade 4.0 in GB / T 9776-2022 “Building Gypsum”;

[0052] The stone powder meets the lower limit performance requirements in GB / T 35164-2017 “Limestone Powder for Use in Cement, Mortar and Concrete”;

[0053] The fly ash meets the performance requirements of grade I in GB / T 1596-2017 “Fly Ash for Use in Cement and Concrete”;

[0054] The gypsum retarder is an amino acid type retarder (for example, ZJ-G19 from Jiangsu Zhaojia Building Material Technology Co., Ltd.) or a protein type retarder (for example, ZJ-G20 from Jiangsu Zhaojia Building Material Technology Co., Ltd.).

[0055] The present application also provides a preparation method of the non-autoclaved artificial aggregate, which comprises the following steps:

[0056] Step 1, homogenization:

[0057] The raw materials and water are weighed according to the ratio and added to a mixer, and after the raw materials are uniformly stirred, they are sent to a homogenization bin, and the raw materials are homogenized for 10-30 min, and the water content of the homogenized raw materials is 9%-16%;

[0058] Step 2, granulation:

[0059] The raw materials in the homogenization bin are sent to a granulator through a conveying device, and the raw materials are granulated, and after the granulation is completed, the semi-finished product is obtained through screening.

[0060] Step 3, solid particles:

[0061] The semi-finished material is subjected to rotary motion in the rotary drum, and the semi-finished material is consolidated, that is, the solid particle operation is performed;

[0062] Step 4, drying:

[0063] The semi-finished material is sent to the bulk material area, and is subjected to hot air drying and dry powder drying to obtain a mixed material with clear particles.

[0064] Step 5, screening:

[0065] The mixed material after bulk material is screened and divided into zones, and then is packaged to obtain artificial aggregates in different particle size ranges.

[0066] In the specific embodiment of the present application, in step 2, the material is atomized and watered during the granulation process, and the water spraying mode is intermittent, and the water spraying time is 5-10s each time.

[0067] In the granulator, the material at the bottom of the granulator is continuously cleaned to prevent the material from adhering to the bottom of the granulator. The inside of the granulator is provided with a nozzle to atomize water on the material, which can supplement water in time when the material is dried. The atomized watering method can be beneficial to the formation of particles and improve the strength of the particles.

[0068] In the specific embodiment of the present application, in step 2, the inclination angle of the granulating disc during granulation is 30°-60°, the radius of the granulating disc is 1.8-2.0m, the rotating speed of the granulating disc is 20-30r / min, the granulation time is 4-6min, and the particle size of the semi-finished material is 5-20mm.

[0069] During granulation, more than 70% of the raw material particles need to rise to a height exceeding the radius of the granulating disc, and the raw material particles blocked by the blocking plate are not more than 20%.

[0070] The granulated raw material can enter the upper rotary horizontal screening drum, the inner layer screen mesh has a pore size equal to the maximum particle size of the product, the outer layer screen mesh has a pore size equal to the minimum size of the product, and the feeding end of the double-layer rotary horizontal screening drum is higher than the discharging end by a part, so as to ensure that the particles thrown out of the granulator enter the inner layer screen mesh of the double-layer rotary horizontal screening drum. After screening, the semi-finished material is formed in the particle size range of 5-20mm, and small particle material and large particle material. The small particle material reenters the granulator, and the large particle material enters the granulator again after being crushed.

[0071] In the specific embodiment of the present application, the particle formation rate of the semi-finished material obtained after granulation reaches more than 80%.

[0072] In the specific embodiment of the present application, the rotating speed of the rotating movement in step 3 is 20-25 r / min, the radius of the rotating cylinder is 0.6-0.8 m, the solidification time of the solid particles is 240-300 s, and the forward moving speed of the semi-finished material is 0.5-1.0 m / min (the semi-finished material moves through the solidification zone, the drying zone and the screening zone in this order at this forward moving speed).

[0073] The rotating cylinder is a cylinder body that is inclined downward along the process direction, and the cylinder body can rotate and is sequentially provided with a solid particle zone, a loose particle zone and a particle separation zone along the process direction. Under the action of gravity, the particles in the rotating cylinder move forward slowly as a whole, and the particles are pressed against each other in the process of moving, so that the particles are more compact, and the solidification process of the particles is completed.

[0074] When the particles are solidified, more than 90% of the particles of the semi-finished material rise with the rotating cylinder to a height exceeding the radius of the rotating cylinder, while ensuring that the particles do not tightly adhere to the inner wall of the rotating cylinder and move along the entire circumference of the rotating cylinder.

[0075] In the specific embodiment of the present application, the temperature of the hot air drying is 80-150℃, and the time of the hot air drying is 0.5-2 min.

[0076] In the specific embodiment of the present application, the dry powder drying is performed by spraying, the spraying speed is 40-60 kg / min, and the spraying time is 0.5-2 min.

[0077] The sprayed dry powder is any one or a mixture of more than one of cement powder, gypsum powder or fly ash powder.

[0078] The hot air drying and the dry powder drying are both performed during the rotating movement of the material, and after the material particles are dried by the hot air, the particles are no longer bonded to each other. In order to further reduce the bonding effect between the particles, the particles are sprayed with dry powder to ensure that the particles are in a dispersed state.

[0079] In the specific embodiment of the present application, particles with a particle size in the range of 5-10 mm, 10-15 mm and 15-20 mm are obtained.

[0080] The present application relates to a kind of artificial aggregate of non-autoclaved and its preparation method, and the artificial aggregate is prepared by the following steps.

[0081] The raw materials used in the following examples are as follows:

[0082] The cement is ordinary Portland cement, which meets the performance requirements of P·O52.5 in GB 175-2007 "General Portland Cement", and the bulk density is 1133 g / L.

[0083] The building gypsum powder meets the performance requirements of 4.0 grade in GB / T 9776-2022 "Building Gypsum", wherein the bulk density is 905 g / L;

[0084] The stone powder meets the lower limit performance requirements of GB / T 35164-2017 "Limestone Powder for Use in Cement, Mortar and Concrete", wherein the bulk density is 1038 g / L;

[0085] The fly ash meets the performance requirements of grade I in GB / T 1596-2017 "Fly Ash for Use in Cement and Concrete", wherein the bulk density is 948 g / L.

[0086] The gypsum retarder is an amino acid type retarder (Jiangsu Zhaojia Building Material Technology Co., Ltd., ZJ-G19).

[0087] Example 1

[0088] The preparation method of the non-autoclaved artificial aggregate provided in this embodiment includes the following steps:

[0089] The preparation method of the non-autoclaved artificial aggregate provided in this embodiment includes the following steps:

[0090] Step 1, homogenization:

[0091] The raw materials and water are weighed according to the proportion and added to the mixer. After the raw materials are uniformly stirred, they are sent to the homogenization bin. The raw materials are homogenized for 20 min, and the water content of the homogenized raw materials is 13%;

[0092] Step 2, granulation:

[0093] The raw materials in the homogenization bin are sent to the granulator through the conveying equipment, and the raw materials are granulated. After granulation, the semi-finished product is obtained by screening;

[0094] The inclination angle of the granulating disc is 45°, the radius of the granulating disc is 2.0 m, the rotation speed of the granulating disc is 25 r / min, the granulation time is 5 min, and the particle size of the semi-finished product is 5-20 mm;

[0095] During the granulation process, the material is atomized and water is added. The water spraying method is intermittent, and each spraying time is 5 s. The particle forming rate of the semi-finished product obtained after granulation reaches more than 80%;

[0096] Step 3, solidification:

[0097] The semi-finished product is subjected to solidification operation in the rotary drum, i.e., the semi-finished product is subjected to solidification operation in the rotary drum.

[0098] Wherein, the rotating speed of the rotary motion is 25r / min, the radius of the rotary cylinder is 0.8m, the time of the solid particles is 280s, and the forward moving speed of the semi-finished product is 1.0mm / min.

[0099] Step 4, drying:

[0100] The semi-finished product of the end of the solid material is sent to the granular area, and hot air drying and dry powder drying are respectively carried out to obtain the mixed material with clear particles;

[0101] Wherein, the temperature of the hot air drying is 120℃, and the time of the hot air drying is 1min; the dry powder drying adopts the spraying mode, the spraying speed is 50kg / min, the spraying time is 1min; and the sprayed dry powder is cement powder.

[0102] Step 5, screening:

[0103] The mixed material after granulation is screened and divided into areas, and then packaged to obtain the artificial aggregate (particle size range is 5-10mm, 10-15mm, 15-20mm).

[0104] The artificial aggregate prepared in the embodiment of the application is tested for performance, wherein the bulk density test method is carried out according to the 6th item of the bulk density method in GB / T 17431.2-2010 “Lightweight Aggregate and Its Test Methods Part 2: Test Methods for Lightweight Aggregate”; and the cylinder compressive strength test method is carried out according to the 9th item of the cylinder compressive strength method in GB / T 17431.2-2010 “Lightweight Aggregate and Its Test Methods Part 2: Test Methods for Lightweight Aggregate”.

[0105] The cylinder compressive strength of the artificial aggregate prepared in the embodiment of the application is 4.2MPa, and the bulk density is 784g / L (5-10mm), wherein the larger the average particle size, the smaller the bulk density, and the bulk density of the 10-20mm aggregate is 85%~90% of the bulk density of the 5-10mm aggregate.

[0106] Example 2

[0107] The difference between the embodiment and example 1 is that the formula of the artificial aggregate is different, and the preparation method of the artificial aggregate is the same as that of example 1, which will not be repeated here.

[0108] The formula of the artificial aggregate used in the embodiment is as follows:

[0109] The artificial aggregate comprises mixed material and water; the mixed material comprises the following components in mass percentage: cement 15%, fly ash 35% and stone powder 50%; and the amount of water is 14% of the total mass of the mixed material.

[0110] The cylinder compressive strength of the artificial aggregate prepared in the embodiment is 4.8 MPa, and the bulk density is 820 g / L (5-10 mm) by using the same test method as in Embodiment 1.

[0111] Embodiment 3

[0112] The difference between the embodiment and Embodiment 1 is that the formula of the artificial aggregate is different, and the preparation method of the artificial aggregate is the same as that of Embodiment 1, which will not be repeated here.

[0113] The formula of the artificial aggregate used in the embodiment is as follows:

[0114] The artificial aggregate comprises a mixture and water; the mixture comprises the following components in percentage by mass: cement 50%, fly ash 30%, and stone powder 20%; the amount of water is 13% of the total mass of the mixture.

[0115] The cylinder compressive strength of the artificial aggregate prepared in the embodiment is 9.5 MPa, and the bulk density is 862 g / L (5-10 mm) by using the same test method as in Embodiment 1.

[0116] Embodiment 4

[0117] The difference between the embodiment and Embodiment 1 is that the formula of the artificial aggregate is different, and the preparation method of the artificial aggregate is the same as that of Embodiment 1, which will not be repeated here.

[0118] The formula of the artificial aggregate used in the embodiment is as follows:

[0119] The artificial aggregate comprises a mixture and water; the mixture comprises the following components in percentage by mass: cement 30%, fly ash 35%, and stone powder 35%; the amount of water is 13.5% of the total mass of the mixture.

[0120] The cylinder compressive strength of the artificial aggregate prepared in the embodiment is 7.3 MPa, and the bulk density is 854 g / L (5-10 mm) by using the same test method as in Embodiment 1.

[0121] Embodiment 5

[0122] The difference between the embodiment and Embodiment 1 is that the formula of the artificial aggregate is different, and the preparation method of the artificial aggregate is the same as that of Embodiment 1, which will not be repeated here.

[0123] The formula of the artificial aggregate used in the embodiment is as follows:

[0124] The artificial aggregate comprises a mixture, a gypsum retarder and water; the mixture comprises the following components in percentage by mass: 60% of building gypsum powder, 20% of fly ash and 20% of stone powder; the amount of water is 24% of the total mass of the mixture; the amount of the gypsum retarder is 0.18% of the mass of the building gypsum powder.

[0125] The cylinder compressive strength of the artificial aggregate prepared in the embodiment is 3.2 MPa, and the bulk density is 682 g / L (5-10 mm) by using the same test method as in Embodiment 1.

[0126] Embodiment 6

[0127] The difference between the embodiment and Embodiment 1 is that the formula of the artificial aggregate is different, and the preparation method of the artificial aggregate is the same as that of Embodiment 1, which is not described herein.

[0128] The formula of the artificial aggregate used in the embodiment is as follows:

[0129] The artificial aggregate comprises a mixture, a gypsum retarder and water; the mixture comprises the following components in percentage by mass: 60% of building gypsum powder, 20% of fly ash and 20% of stone powder; the amount of water is 24% of the total mass of the mixture; the amount of the gypsum retarder is 0.18% of the mass of the building gypsum powder.

[0130] The cylinder compressive strength of the artificial aggregate prepared in the embodiment is 3.2 MPa, and the bulk density is 682 g / L (5-10 mm) by using the same test method as in Embodiment 1.

[0131] Embodiment 7

[0132] The difference between the embodiment and Embodiment 1 is that the formula of the artificial aggregate is different, and the preparation method of the artificial aggregate is the same as that of Embodiment 1, which is not described herein.

[0133] The formula of the artificial aggregate used in the embodiment is as follows:

[0134] The artificial aggregate comprises a mixture, a gypsum retarder and water; the mixture comprises the following components in percentage by mass: 60% of building gypsum powder, 20% of fly ash and 20% of stone powder; the amount of water is 24% of the total mass of the mixture; the amount of the gypsum retarder is 0.18% of the mass of the building gypsum powder.

[0135] The cylinder compressive strength of the artificial aggregate prepared in the embodiment is 3.2 MPa, and the bulk density is 682 g / L (5-10 mm) by using the same test method as in Embodiment 1.

[0136] Comparative Examples 1-7, the bulk density test results of the cement, building gypsum powder, stone powder, fly ash used in Examples 1-7 are 1133 g / L, 905 g / L, 1038 g / L, 948 g / L, respectively, and the bulk density of the product is greatly related to the bulk density of the raw materials used when the production process is unchanged. As can be seen from the test data, the bulk density of cement is the largest, followed by stone powder, fly ash, and gypsum powder. In Comparative Examples 1-7, the greater the proportion of raw materials with high bulk density, the greater the bulk density of the product under the same production process. The cylinder compressive strength is directly related to the content of cementitious materials. Generally speaking, the higher the proportion of cementitious materials, the greater the strength.

[0137] Comparative Example 1

[0138] The difference between the present comparative example and Example 1 is that the formulation of the artificial aggregate is different, and the preparation method of the artificial aggregate is the same as that of Example 1, which will not be repeated here.

[0139] The formulation of the artificial aggregate used in the present comparative example is as follows, in terms of mass percentage:

[0140] Cement 10%, fly ash 55%, and stone powder 35%; the amount of water is 13% of the total mass of the mixture.

[0141] Due to the low content of cementitious material cement, the aggregate forming rate is low (less than 70%) under the same production process, and the powder is more, so the material is not easy to form during preparation and is easy to scatter. Using the same test method as in Example 1, the cylinder compressive strength of the artificial aggregate prepared in the present comparative example is 2.7 MPa, and the bulk density is 790 g / L (5-10 mm).

[0142] Comparative Example 2

[0143] The difference between the present comparative example and Example 1 is that the formulation of the artificial aggregate is different, and the preparation method of the artificial aggregate is the same as that of Example 1, which will not be repeated here.

[0144] The formulation of the artificial aggregate used in the present comparative example is as follows, in terms of mass percentage:

[0145] Cement 60%, fly ash 20%, and stone powder 20%; the amount of water is 13% of the total mass of the mixture.

[0146] Due to the high content of cementitious material cement, it is easy to form a large lump during the forming process, and the material cost of the aggregate is relatively high. Using the same test method as in Example 1, the cylinder compressive strength of the artificial aggregate prepared in the present comparative example is 12.6 MPa, and the bulk density is 896 g / L (5-10 mm).

[0147] The above merely illustrates the preferred embodiments of the present application, and is not used to limit the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A non-autoclaved artificial aggregate, characterized by, The artificial aggregate comprises a mixture and water; the mixture comprises cementitious material, fly ash and stone powder; the cementitious material is cement or building gypsum powder; When the cementitious material is cement, the mixture comprises the following raw material components in percentage by mass: cement 15-50%, fly ash 30-65% and stone powder 20-85%; the amount of water is 10%-20% of the total mass of the mixture; When the cementitious material is building gypsum powder, the mixture comprises the following raw material components in percentage by mass: building gypsum powder 60-85%, fly ash 5-30%, stone powder 10-40% and gypsum retarder; the amount of water is 20%-30% of the total mass of the mixture; the amount of gypsum retarder is 0.1%-0.4% of the mass of the building gypsum powder; The preparation method of the non-autoclaved artificial aggregate comprises the following steps: Step 1, homogenization: According to the proportion, each raw material and water are weighed and added into a mixer, the raw materials are uniformly stirred and then sent into a homogenization bin, and the raw materials are homogenized for 10-30 min, and the water content of the homogenized mixture is 9%-16%; Step 2, granulation: The mixture in the homogenization bin is sent into a granulator through conveying equipment, and the mixture is granulated, and after granulation, screening is performed to obtain semi-finished products; Step 3, solidification: The semi-finished products are subjected to rotary motion in a rotary cylinder to consolidate the semi-finished products, i.e., solidification operation; Step 4, drying: The semi-finished products after solidification are sent into a bulk zone, and hot air drying is performed first, and then dry powder drying is performed to obtain a mixture with clear particles; Step 5, screening: The bulk mixture is screened and then packaged to obtain artificial aggregates in different particle size ranges.

2. The non-autoclaved artificial aggregate according to claim 1, characterized in that The cement is ordinary Portland cement, which meets the performance requirements of P·O52.5 in GB 175-2007 “General Portland Cement”; The building gypsum powder meets the performance requirements of grade 4.0 in GB / T 9776-2022 “Building Gypsum”; The stone powder meets the lower limit performance requirements in GB / T 35164-2017 “Limestone Powder for Use in Cement, Mortar and Concrete”; The fly ash meets the performance requirements of grade I in GB / T 1596-2017 “Fly Ash for Use in Cement and Concrete”; The gypsum retarder is an amino acid type or a protein type.

3. The non-autoclaved artificial aggregate according to claim 1, wherein In step 2, water is added to the material during granulation by intermittent spraying, and each spraying time is 5-10 s.

4. The non-autoclaved artificial aggregate according to claim 1, wherein In step 2, the inclination angle of the granulation disc during granulation is 30°-60°, the radius of the granulation disc is 1.8-2.0 m, the rotation speed of the granulation disc is 20-30 r / min, the granulation time is 4-6 min, and the particle size of the semi-finished products is 5-20 mm; In step 3, the rotation speed of the rotary motion is 20-25 r / min, the radius of the rotary cylinder is 0.6-0.8 m, the solidification time is 240-300 s, and the forward movement speed of the semi-finished products is 0.5-1.0 m / min.

5. The non-autoclaved artificial aggregate according to claim 1, wherein In step 4, the temperature of the hot air drying is 80-150℃, and the time of the hot air drying is 0.5-2min; The dry powder is sprayed, and the spraying speed is 40-60kg / min, and the spraying time is 0.5-2min; The sprayed dry powder is any one or a mixture of more than one of cement powder, gypsum powder or fly ash powder.

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