Method for preparing glassy single cavity hollow particles using perlite tailings

Abstract

The application provides a method for preparing glassy single-cavity hollow particles by using perlite tailings, which can process the perlite tailings with a particle size less than 300 mesh into glassy single-cavity hollow particles with good roundness and high strength, so that the glassy single-cavity hollow particles can be used to make light aggregate thermal refractory materials, composite materials and filling materials of various engineering materials, etc., so that the waste resource of the perlite tailings with a particle size less than 300 mesh can be recycled, so as to avoid resource waste and ecological environment destruction. Moreover, the method for preparing glassy single-cavity hollow particles by using perlite tailings in the embodiment of the application adopts vertical roasting furnace bottom feeding, and realizes disaggregation and agglomeration of particles by adding triethanolamine, so that the perlite micro-powder raw material has good fluidity and dispersity, the agglomeration of the perlite micro-powder raw material with a particle size less than 300 mesh in the roasting process can be effectively prevented, and the perlite micro-powder raw material is prevented from being bonded on the side wall of the hearth to cause the hearth blockage.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of glass hollow particle processing, in particular, relates to a method for preparing glass single-cavity hollow particles by using perlite tailings. BACKGROUND

[0002] Perlite is a kind of acidic lava formed by rapid cooling of volcanic eruption, and when producing expanded perlite products, perlite tailings smaller than 120 mesh will be produced. The perlite tailings are generally discarded, which not only wastes resources but also affects the ecological environment.

[0003] Currently, vitrified microbead production uses vertical auxiliary radiation heating furnaces for calcination. The perlite material is heated after being fed from the top feeder and forms a finished product by relying on the gravity of the perlite particles. However, when the perlite particles are smaller than 200 mesh, the thermal air buoyancy generated during calcination in the heating furnace will be greater than the self-gravity of the perlite particles, which will cause the perlite to quickly adhere to the side wall of the heating furnace, resulting in the blockage of the heating furnace. In addition, vitrified microbead particles processed by vertical auxiliary radiation heating furnaces are generally irregular spherical particles with a multi-cavity loose structure, resulting in poor roundness and low strength of the vitrified microbead particles. SUMMARY

[0004] Based on the above problems in the prior art, the purpose of the embodiments of the present application is to provide a method for preparing glass single-cavity hollow particles by using perlite tailings. The perlite tailings smaller than 300 mesh are calcined by a vertical calcination furnace to prepare glass single-cavity hollow particles with good roundness and high strength.

[0005] To achieve the above purpose, the technical solution adopted by the present application is to provide a method for preparing glass single-cavity hollow particles by using perlite tailings, comprising the following steps:

[0006] Step S01: mixing perlite and perlite tailings to obtain perlite premix;

[0007] Step S02: feeding the perlite premix into a superfine grinding mill and spraying triethanolamine during the grinding process of the premix in the superfine grinding mill to obtain a material to be used with a particle size of less than 300 mesh after grinding;

[0008] Step S03: feeding the material to be used, glass micro-powder and fluorite into a strong fluidized gas drying furnace to obtain dispersed perlite micro-powder raw material;

[0009] Step S04: The pearl stone micro-powder raw material is placed into a strong fluidized gas drying furnace for drying, and neutral silica sol liquid is sprayed into the strong fluidized gas drying furnace by using an ultra-micro atomization method, and the pearl stone micro-powder particles coated with the neutral silica sol on the surface are obtained after drying.

[0010] Step S05: The pearl stone micro-powder particles coated with the neutral silica sol on the surface are placed into a vertical calcining furnace for calcination, and the glassy single-cavity hollow particles are prepared.

[0011] Optionally, in the step S01, the mass ratio of the pearl stone to the pearl stone tailings is (2-3):(7-8), and the mass of the triethanolamine sprayed accounts for 0.08%-0.1% of the total mass of the pearl stone and the pearl stone tailings.

[0012] Optionally, in the step S03, the particle size of the to-be-used material is 300-800 mesh, the particle size of the glass micro-powder is 1500-3000 mesh, and the particle size of the fluorite is 1500-3000 mesh.

[0013] Optionally, in the step S03, the mass percentage of the to-be-used material is 80%-94.5%, the mass percentage of the glass micro-powder is 5%-20%, and the mass percentage of the fluorite is 0.5%-1%, based on the total mass of the to-be-used material, the glass micro-powder and the fluorite being 100%.

[0014] Optionally, in the step S04, the volume ratio of the pearl stone micro-powder particles to the neutral silica sol liquid is (5-7):(13-15).

[0015] Optionally, in the step S04, the concentration of the neutral silica sol liquid is 15%-25%.

[0016] Optionally, in the step S05, the length-diameter ratio of the vertical calcining furnace is (1-1.5):6, and the distance between the inner liner of the vertical calcining furnace and the outer shell of the vertical calcining furnace is greater than or equal to 200 mm.

[0017] Optionally, in the step S05, the volume ratio of the settling chamber of the vertical calcining furnace to the hearth of the vertical calcining furnace is greater than 7:1.

[0018] Optionally, in the step S05, a plurality of burners are arranged on the vertical calcining furnace, the plurality of burners are arranged at intervals along the circumference of the vertical calcining furnace, and the number of the burners is odd.

[0019] Optionally, the hydrostatic pressure strength of the glassy single-cavity hollow particles is greater than 1.5 MPa, and the thermal conductivity of the glassy single-cavity hollow particles is lower than 0.043 W / (m·K).

[0020] Compared with the prior art, one or more technical solutions in the embodiments of the present invention have at least one of the following beneficial effects:

[0021] The method for preparing glassy single-cavity hollow particles using perlite tailings in this embodiment of the invention can process perlite tailings with a particle size of less than 300 mesh into glassy single-cavity hollow particles with better roundness and higher strength. These glassy single-cavity hollow particles can then be used to produce lightweight aggregate insulation and refractory materials, composite materials, and fillers for various engineering materials. This allows for the recycling and reuse of perlite tailings with a particle size of less than 300 mesh, avoiding resource waste and environmental damage. Furthermore, the method for preparing glassy single-cavity hollow particles using perlite tailings in this embodiment of the invention employs bottom feeding in a vertical roasting furnace and adds triethanolamine to deagglomerate the particles. This gives the perlite powder raw material good flowability and dispersibility, effectively preventing agglomeration of perlite powder with a particle size of less than 300 mesh during roasting and avoiding furnace blockage caused by agglomerated perlite powder adhering to the furnace sidewalls. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the main structure of a production line for preparing glassy single-cavity hollow particles using perlite tailings, provided in an embodiment of the present invention.

[0023] Figure 2 This is a schematic diagram of the main structure of a vertical calcining furnace for preparing glassy single-cavity hollow particles using perlite tailings, provided in an embodiment of the present invention.

[0024] Figure 3 This is a bottom view of the vertical roasting furnace for preparing glassy single-cavity hollow particles using perlite tailings, as provided in an embodiment of the present invention.

[0025] The figures in the diagram are labeled as follows:

[0026] 1-Raw material silo; 2-Variable frequency screw weigher;

[0027] 3-Vertical roasting furnace; 31-Furnace chamber; 32-Settling chamber;

[0028] 4-Cyclone dust collector; 5-Pulse jet bag filter; 6-Exhaust fan;

[0029] 7-Feeding blower; 8-Storage silo; 9-High temperature blower;

[0030] 10 - Feed pipe; 20 - Burner. Detailed Implementation

[0031] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present application more clear and explicit, the present application is further described in detail below in combination with the drawings and examples. It should be understood that the specific examples described herein are only used to explain the present application and do not limit the present application.

[0032] The method for preparing glassy single cavity hollow particles by using perlite tailings provided by the embodiment of the present application comprises the following steps:

[0033] Step S01: mixing perlite and perlite tailings to obtain perlite premix.

[0034] Step S02: putting the perlite premix into the ultrafine grinding mill, and spraying triethanolamine during the grinding process of the premix in the ultrafine grinding mill, and obtaining the material to be used with a particle size less than 300 mesh after grinding. By adding triethanolamine, the agglomerated perlite particles are depolymerized, so that the perlite particles have good fluidity and dispersibility, which is beneficial to the calcination processing of the perlite particles in the vertical calcination furnace 3 later.

[0035] Step S03: putting the material to be used, glass micro powder and fluorite into the strong fluidized gas drying furnace to obtain dispersed perlite micro powder raw material. The strong fluidized gas drying furnace is used for drying, the purpose of which is to prevent the perlite micro powder raw material particles from agglomerating again and reduce the good fluidity and dispersibility of the perlite micro powder raw material, so as to further overcome the defect that the perlite micro powder raw material with a particle size less than 300 mesh agglomerates during the calcination process.

[0036] Step S04: putting the perlite micro powder raw material into the strong fluidized gas drying furnace for drying, and spraying neutral silica sol solution into the strong fluidized gas drying furnace by using the ultrafine atomization method, and obtaining perlite micro powder particles coated with neutral silica sol on the surface after drying;

[0037] Step S05: putting the perlite micro powder particles coated with neutral silica sol into the vertical calcination furnace 3 for calcination, and glassy single cavity hollow particles can be prepared.

[0038] Compared with the prior art, the method for preparing glassy single-cavity hollow particles from perlite tailings provided by the embodiment of the present application can process perlite tailings with particle size less than 300 mesh into glassy single-cavity hollow particles with better roundness and higher strength, so that the glassy single-cavity hollow particles can be used to make light aggregate thermal insulation refractory materials, composite materials and filling materials of various engineering materials, etc., so that the waste resource of perlite tailings with particle size less than 300 mesh can be recycled, so as to avoid resource waste and damage to the ecological environment. Moreover, in the method for preparing glassy single-cavity hollow particles from perlite tailings, the bottom of the vertical roasting furnace 3 is used for feeding, and triethanolamine is added to realize the deagglomeration of the agglomerated particles, so that the perlite micro-powder raw material has good fluidity and dispersibility, which can effectively prevent the agglomeration of the perlite micro-powder raw material with particle size less than 300 mesh during the roasting process, and avoid the agglomerated perlite micro-powder raw material from being bonded on the side wall of the hearth to cause the hearth to be blocked.

[0039] It should be noted that in step S01, the mass ratio of perlite to perlite tailings is (2-3):(7-8), and the mass of the sprayed triethanolamine accounts for 0.08%-0.1% of the total mass of the perlite and the perlite tailings. When the perlite pre-mixed material composed of perlite and perlite tailings is ground into perlite particles with particle size less than 300 mesh, agglomeration is easy to occur and snowflake-shaped agglomerates are formed, so that the particles are not easy to disperse. By controlling the dosage ratio of perlite to perlite tailings and adding triethanolamine matching the total dosage of perlite and perlite tailings, the agglomerated perlite particles can be effectively deagglomerated, so that the perlite particles have good fluidity and dispersibility, which is beneficial to improve the quality of the perlite particles during the later roasting process in the vertical roasting furnace 3.

[0040] It should be noted that in step S02, after the perlite pre-mixed material is ground into the material to be used with particle size less than 300 mesh, the material to be used can be classified, the material to be used with particle size of 300-800 mesh is classified as A-grade material, and the material to be used with particle size less than 800 mesh is classified as B-grade material, so as to facilitate processing according to the different particle sizes of the material to be used, and improve the consistency of the volume of the perlite after roasting and expansion.

[0041] It should be noted that in step S03, the particle size of the material to be used is 300-800 mesh, the particle size of the glass powder is 1500-3000 mesh, and the particle size of the fluorite is 1500-3000 mesh. Among them, the mass percentage of the material to be used is 80%-94.5%, the mass percentage of the glass powder is 5%-20%, and the mass percentage of the fluorite is 0.5%-1%, based on the total mass of the material to be used, the glass powder and the fluorite being 100%. By controlling the particle size and amount of the material to be used, the glass powder and the fluorite, and by drying in the strong fluidized gas drying furnace under the synergistic action of the material to be used, the glass powder and the fluorite, a well-dispersed pearl stone powder raw material can be obtained.

[0042] It should be noted that in step S04, the volume ratio of pearl stone powder particles to neutral silica sol solution is (5-7):(13-15), and by controlling the volume of pearl stone powder particles and neutral silica sol solution, the neutral silica sol uniformly coats the surface of the pearl stone powder particles.

[0043] It should be noted that in step S04, the concentration of the neutral silica sol solution is 15%-25%, and the water content of the pearl stone powder particles coated with the neutral silica sol is controlled at 1.8%-2.2%, which is conducive to the uniform coating of the silica sol droplets on the surface of the pearl stone powder particles by ultra-micro atomization, and is conducive to improving the roundness and smoothness of the glassy single-cavity hollow particles.

[0044] It should be noted that in step S05, the length-diameter ratio of the vertical roasting furnace 3 is (1-1.5):6, and the distance between the inner shell of the vertical roasting furnace 3 and the outer shell of the vertical roasting furnace 3 is greater than or equal to 200mm, which is conducive to the sufficient roasting of pearl stone powder particles with a particle size less than 300 mesh in the vertical roasting furnace 3, and reduces the possibility of agglomeration of pearl stone powder particles with a particle size less than 300 mesh in the hearth 31 and the formation of snowflake-like agglomerates. Moreover, the inner shell is made of 310S austenitic chromium-nickel stainless steel, and the outer shell is made of 6-8mm heat-resistant steel plate.

[0045] It should be noted that in step S05, the volume ratio of the settling chamber 32 of the vertical roasting furnace 3 to the hearth 31 of the vertical roasting furnace 3 is greater than 7:1. The function of the settling chamber 32 is to properly cool the molten pearl stone powder particles to prevent sudden cooling and cause micro-cracks on the surface of the pearl stone powder particles, resulting in a decrease in strength. By setting the volume ratio of the settling chamber 32 of the vertical roasting furnace 3 to the hearth 31 of the vertical roasting furnace 3 to be greater than 7:1, the molten pearl stone powder particles can be cooled quickly and sufficiently, and agglomeration of the molten pearl stone powder particles can be prevented.

[0046] It should be noted that in step S05, the vertical roasting furnace 3 is provided with a plurality of burners 20, and the plurality of burners 20 are arranged at intervals along the circumference of the vertical roasting furnace 3. The number of burners 20 is odd, which prevents the flames generated by the symmetrically arranged burners 20 from interfering with each other. The elevation angle of the burners 20 can be freely adjusted within an angle range of 0-15°, and the elevation angle of the burners 20 can be adjusted to produce glassy single-cavity hollow particle products of different particle sizes and different bulk densities. The greater the elevation angle of the burners 20, the greater the upward thermal air buoyancy of the perlite powder particle material, the flow rate increases, and the glassy single-cavity hollow particle product produced has a low bulk density and a small thermal conductivity. The glassy single-cavity hollow particle product with a small elevation angle of the burners 20 has a large bulk density.

[0047] It should be noted that the hydrostatic pressure strength of the glassy single-cavity hollow particle is greater than 1.5 MPa, and the thermal conductivity of the glassy single-cavity hollow particle is less than 0.043 W / (m·K).

[0048] The embodiment of the present application also provides a glassy single-cavity hollow particle prepared by the method for preparing the glassy single-cavity hollow particle from the perlite tailings according to any one of the above embodiments. The glassy single-cavity hollow particle prepared by the method for preparing the glassy single-cavity hollow particle from the perlite tailings has a hydrostatic pressure strength greater than 1.5 MPa and a thermal conductivity less than 0.043 W / (m·K), so that the glassy single-cavity hollow particle can be used to make light aggregate thermal insulation refractory materials, composite materials or various engineering material fillers, etc., so that the perlite tailings with a particle size less than 300 mesh, which is a waste resource, can be recycled, so as to avoid resource waste and damage to the ecological environment.

[0049] The embodiment of the present application also provides a production line for preparing glassy single-cavity hollow particles by using perlite tailings, which comprises a raw material bin 1 for storing perlite micro-powder raw materials, a variable-frequency screw scale 2 for weighing the perlite micro-powder raw materials, a vertical calcining furnace 3 for calcining the perlite micro-powder raw materials, a feeding pipe 10 for conveying the weighed perlite micro-powder raw materials from the bottom of the vertical calcining furnace 3 to the hearth 31 of the vertical calcining furnace 3, a cyclone dust collector 4 connected with the top discharge port of the vertical calcining furnace 3, a pulse bag dust collector 5 connected with the cyclone dust collector 4, an induced draft fan 6 connected with the pulse bag dust collector 5, a feeding fan 7 connected with the feeding pipe 10 and the vertical calcining furnace 3, a storage bin 8 for storing glassy single-cavity hollow particle products, and a high-temperature fan 9 connected with the feeding pipe 10, the top discharge port of the vertical calcining furnace 3 and the cyclone dust collector 4. The perlite micro-powder raw materials are conveyed into the hearth 31 of the vertical calcining furnace 3 through the feeding pipe 10 from the bottom of the vertical calcining furnace 3. Since the softening temperature of the perlite is 800 DEG C and the melting temperature is greater than 1080 DEG C, the melting temperature range of the perlite is 280 DEG C. The perlite micro-powder raw materials can be high-temperature melted in the hearth 31 at a temperature range of 800 DEG C to 1080 DEG C, and a spherical shell is formed under the surface tension of the perlite micro-powder raw materials. When the glass cools down to below the softening temperature, it is condensed into a cavity structure, thereby forming glassy single-cavity hollow particles. Due to the unique glassy single-cavity hollow characteristics, the perlite can be made into lightweight aggregate thermal insulation refractory materials, composite materials and the like, or prepared into various functional fillers after surface treatment.

[0050] In order to make the above-mentioned implementation details and operations of the present application be clearly understood by those skilled in the art, and the further performance of the method for preparing glassy single-cavity hollow particles by using perlite tailings provided by the embodiment of the present application be significantly embodied, the following will illustrate the implementation of the present application by examples.

[0051] Example 1

[0052] (1) The perlite and the perlite tailings are mixed according to a mass ratio of 1:4 to obtain perlite premix;

[0053] (2) The perlite premix is put into the ultra-fine grinding mill, and triethanolamine is sprayed into the ultra-fine grinding mill during the grinding process of the premix. The mass of the sprayed triethanolamine accounts for 0.1% of the total mass of the perlite and the perlite tailings. After grinding, the obtained material to be used has a particle size of less than 300 mesh. Then, the material to be used is divided into A-grade material with a particle size of 300-800 mesh and B-grade material with a particle size of less than 800 mesh;

[0054] (3) The 300-800 mesh to-be-used material, 1500 mesh glass powder and 1500 mesh fluorite are mixed according to the mass ratio of 180:19:1, and then are put into the strong fluidization gas drying furnace to obtain the dispersed pearl stone powder raw material;

[0055] (4) The pearl stone powder raw material is put into the strong fluidization gas drying furnace for drying, and the neutral silica sol solution with a concentration of 25% is sprayed into the strong fluidization gas drying furnace by using the ultra-micro atomization method, the volume ratio of the pearl stone powder particles to the neutral silica sol solution is 1:3, and the pearl stone powder particles coated with the neutral silica sol on the surface are obtained after drying, and the water content of the pearl stone powder particles coated with the neutral silica sol on the surface is 2.2%.

[0056] (5) The pearl stone powder particles coated with the neutral silica sol on the surface are put into the vertical calcining furnace for calcination, and the glassy single-cavity hollow particles are prepared.

[0057] The glassy single-cavity hollow particles in the example have a particle size of 100-400 mesh, a circularity greater than 90%, a hydrostatic pressure strength greater than 5 MPa and a thermal conductivity coefficient lower than 0.047 W / (m·K).

[0058] Example 2

[0059] (1) The pearl stone and the pearl stone tailings are mixed according to the mass ratio of 3:7 to obtain the pearl stone premix;

[0060] (2) The pearl stone premix is put into the ultra-fine powder mill, and triethanolamine is sprayed into the ultra-fine powder mill during the grinding of the premix, the mass of the sprayed triethanolamine accounts for 0.08% of the total mass of the pearl stone and the pearl stone tailings, and the to-be-used material with a particle size less than 300 mesh is obtained after grinding, and then the to-be-used material is divided into A-grade material with a particle size of 300-800 mesh and B-grade material with a particle size less than 800 mesh;

[0061] (3) The 300-800 mesh to-be-used material, 3000 mesh glass powder and 3000 mesh fluorite are mixed according to the mass ratio of 80:19:1, and then are put into the strong fluidization gas drying furnace to obtain the dispersed pearl stone powder raw material;

[0062] (4) The pearl stone powder raw material is put into the strong fluidization gas drying furnace for drying, and the neutral silica sol solution with a concentration of 15% is sprayed into the strong fluidization gas drying furnace by using the ultra-micro atomization method, the volume ratio of the pearl stone powder particles to the neutral silica sol solution is 7:13, and the pearl stone powder particles coated with the neutral silica sol on the surface are obtained after drying, and the water content of the pearl stone powder particles coated with the neutral silica sol on the surface is 2%.

[0063] (5) The pearl stone micropowder particles coated with neutral silica sol on the surface are put into a vertical calcining furnace for calcination, and glassy single-cavity hollow particles are prepared.

[0064] The glassy single-cavity hollow particles in the example have a particle size of less than 325 mesh, a circularity of greater than 95%, a hydrostatic pressure strength of greater than 10 MPa, and a thermal conductivity of less than 0.05 W / (m·K).

[0065] Example 3

[0066] (1) Pearl stone and pearl stone tailings are mixed in a mass ratio of 3:10 to obtain pearl stone premix;

[0067] (2) The pearl stone premix is put into a superfine powder mill, and triethanolamine is sprayed into the superfine powder mill during the grinding of the premix, the mass of the sprayed triethanolamine accounting for 0.09% of the total mass of the pearl stone and the pearl stone tailings, and the resulting material after grinding has a particle size of less than 300 mesh, which is then divided into A-grade material with a particle size of 300-800 mesh and B-grade material with a particle size of less than 800 mesh;

[0068] (3) The pearl stone micropowder raw material is obtained by putting the pearl stone micropowder raw material, glass micropowder with a particle size of 2000 mesh, and fluorite with a particle size of 2000 mesh into a strong fluidized gas drying furnace in a mass ratio of 189:10:1;

[0069] (4) The pearl stone micropowder raw material is dried in the strong fluidized gas drying furnace, and a neutral silica sol solution with a concentration of 20% is sprayed into the strong fluidized gas drying furnace by using an ultramicro-atomization method, the volume ratio of the pearl stone micropowder particles to the neutral silica sol solution being 7:16, and the resulting pearl stone micropowder particles coated with neutral silica sol on the surface have a water content of 1.8% after drying.

[0070] (5) The pearl stone micropowder particles coated with neutral silica sol on the surface are put into a vertical calcining furnace for calcination, and glassy single-cavity hollow particles are prepared.

[0071] The glassy single-cavity hollow particles in the example have a particle size of less than 150 mesh, a circularity of greater than 60%, a hydrostatic pressure strength of greater than 1.5 MPa, and a thermal conductivity of less than 0.043 W / (m·K).

[0072] Comparative Example 1

[0073] (1) Pearl stone and pearl stone tailings are mixed in a mass ratio of 3:10 to obtain pearl stone premix;

[0074] (2) the pearl stone premix is put into the ultra-fine grinding mill, and the obtained material with particle size less than 300 mesh is divided into A material with particle size of 300-800 mesh and B material with particle size less than 800 mesh;

[0075] (3) the material with particle size of 300-800 mesh is put into the strong fluidized gas drying furnace, and the dispersed pearl stone micro-powder raw material is obtained;

[0076] (4) the pearl stone micro-powder raw material is put into the strong fluidized gas drying furnace for drying, and the neutral silica sol solution with a concentration of 25% is sprayed into the strong fluidized gas drying furnace by using the ultra-micro atomization method, the volume ratio of the pearl stone micro-powder particles to the neutral silica sol solution is 1:3, and the pearl stone micro-powder particles coated with the neutral silica sol on the surface are obtained after drying, and the water content of the pearl stone micro-powder particles coated with the neutral silica sol on the surface is 2.2%.

[0077] (5) the pearl stone micro-powder particles coated with the neutral silica sol on the surface are put into the vertical auxiliary radiation heating furnace from the top of the vertical auxiliary radiation heating furnace by using the top material distributor for calcination, and the vitrified microbeads are obtained.

[0078] It is tested that the vitrified microbeads in the comparative example 1 are irregular spherical particles with a multi-cavity loose structure, the particle size is 95-360 mesh, the circularity is less than 60%, the hydrostatic strength is less than 1.4 MPa, and the thermal conductivity is higher than 0.053 W / (m·K).

[0079] The test results of the glassy single-cavity hollow particles in the above examples 1-3 and the vitrified microbeads in the comparative example 1 are shown in Table 1.

[0080] Table 1 Test results of the glassy single-cavity hollow particles in the examples 1-3 and the vitrified microbeads in the comparative example 1

[0081] Test item Example 1 Example 2 Example 3 Comparative Example 1 Is it a single-cavity compact structure? Yes Yes Yes No Is it a multi-cavity loose structure? No No No Yes Circularity (%) >90 >95 >60 <60 Hydrostatic strength (MPa) >5 >10 >1.5 <1.4 Thermal conductivity (W / m-K) <0.047 <0.05 <0.043 >0.53 Particle size (mesh) 100～400 <325 <150 95～360

[0082] It can be seen from Table 1 that, compared with the vitrified microbeads in the comparative example 1, the glassy single-cavity hollow particles prepared in the examples 1-3 have a single-cavity tight structure, better circularity, higher strength and lower thermal conductivity, and can be made into light aggregate thermal and refractory materials, composite materials and the like, or prepared into various functional fillers after surface treatment.

[0083] The above only describes the preferred embodiments of the present application, and is not used to limit the present application, any modification, equivalent replacement and improvement made within the spirit and principle of the present application should be included in the protection scope of the present application.

Claims

1. A method for preparing glassy single-cavity hollow particles using perlite tailings, characterized in that, Includes the following steps: Step S01: Mix the pearlite and pearlite tailings to obtain a pearlite premix; Step S02: The perlite premix is ​​fed into an ultrafine mill, and triethanolamine is sprayed in during the milling process. After milling, a material with a particle size of less than 300 mesh is obtained. Step S03: The materials to be used, glass micro powder and fluorite are fed into a high-intensity fluidized bed gas drying furnace to obtain dispersed perlite micro powder raw material; Step S04: The perlite powder raw material is placed in a high-power fluidized gas drying oven for drying, and a neutral silica sol solution is sprayed into the high-power fluidized gas drying oven using an ultra-micro atomization method. After drying, perlite powder particles with a surface coated with neutral silica sol are obtained. Step S05: The perlite micro-powder particles coated with neutral silica sol are placed into a vertical calcining furnace for calcination to obtain glassy single-cavity hollow particles. In step S01, the mass ratio of the perlite to the perlite tailings is (2-3):(7-8), and the mass of the triethanolamine injected accounts for 0.08% to 0.1% of the total mass of the perlite and the perlite tailings. In step S03, based on the total mass of the material to be used, the glass micro powder, and the fluorite as 100%, the mass percentage of the material to be used is 80% to 94.5%, the mass percentage of the glass micro powder is 5% to 20%, and the mass percentage of the fluorite is 0.5% to 1%. In step S04, the volume ratio of the perlite microparticles to the neutral silica sol is (5-7):(13-15). In step S04, the concentration of the neutral silica sol solution is 15% to 25%.

2. The method for preparing glassy single-cavity hollow particles using perlite tailings as described in claim 1, characterized in that, In step S03, the particle size of the material to be used is 300-800 mesh, the particle size of the glass micro powder is 1500-3000 mesh, and the particle size of the fluorite is 1500-3000 mesh.

3. The method for preparing glassy single-cavity hollow particles using perlite tailings as described in claim 1, characterized in that, In step S05, the length-to-diameter ratio of the vertical roasting furnace is (1~1.5):6, and the distance between the inner liner of the vertical roasting furnace and the outer shell of the vertical roasting furnace is greater than or equal to 200mm.

4. The method for preparing glassy single-cavity hollow particles using perlite tailings as described in claim 1, characterized in that, In step S05, the ratio of the settling chamber volume to the furnace volume of the vertical roasting furnace is greater than 7:

1.

5. The method for preparing glassy single-cavity hollow particles using perlite tailings as described in claim 1, characterized in that, In step S05, the vertical roasting furnace is provided with multiple burners, which are arranged at intervals along the circumference of the vertical roasting furnace, and the number of burners is odd.

6. The method for preparing glassy single-cavity hollow particles using perlite tailings as described in any one of claims 1 to 5, characterized in that, The hydrostatic pressure of the glassy single-cavity hollow particles is greater than 1.5 MPa, and the thermal conductivity of the glassy single-cavity hollow particles is less than 0.043 W / (m·K).

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