Granulation method and system for improving bulk density of synthesized high-purity quartz sand

Abstract

The invention discloses a granulation method and system for improving the bulk density of synthesized high-purity quartz sand, and the method comprises the following steps: carrying out spraying treatment on silica sol to form silica sol liquid drops, and meanwhile, carrying out microwave drying on the silica sol liquid drops to uniformly heat the inside and outside of the silica sol liquid drops to obtain preliminarily dried gel particles; and putting the gel particles into drying equipment for drying treatment to obtain a granulated product. The hollow rate of the granulated product can be greatly reduced, so that the stacking density of the synthesized high-purity quartz sand product is improved, a solid particle product with few defects is prepared, the number of bubbles in a downstream product is effectively reduced, and meanwhile, the bubble size in the downstream product can be effectively reduced.

Description

Technical Field

[0001] The invention belongs to the technical field of quartz sand, and in particular relates to a granulation method and a system for improving the bulk density of synthetic high-purity quartz sand. Background Art

[0002] Quartz manufacturing and photovoltaic materials industries require solid granular quartz sand. Quartz sand that is too small or too large cannot be used in the production and manufacturing of quartz products. At present, there is a technology of spray granulation to prepare quartz sand particles with uniform particle size. However, due to the particularity of the production process, the quartz sand particles prepared by the current spray granulation technology are hollow particles with low strength. The produced quartz products have many bubbles and do not meet the product requirements of the industry. Therefore, how to produce solid granular quartz sand has become an urgent problem to be solved in the current industry.

[0003] Common spray granulation is a method of obtaining solid particles by heating (cooling) the material particles from the outside under the action of hot (cold) airflow. Under the action of airflow, this method usually causes the material particles to solidify on the outside first and then sink and collapse inward, resulting in a large number of overfine particles and pore defects in the particles.

[0004] Vibration spray granulation is a granulation technology that produces uniform droplets by applying vibration or periodic disturbance to the jet. Compared with other granulation technologies, this technology can greatly improve the particle size distribution, improve product quality, and reduce environmental pollution and product losses caused by fine particles being entrained by air. However, the existing conventional vibration spray granulation equipment uses a refrigerant to cool the material. It is suitable for cooling and granulating molten materials. If it is used to process materials such as silica sol for dry granulation, the temperature inside and outside the droplets will be different, and the outside will dry to form a hard shell, which will make the internal liquid unable to be effectively separated, resulting in the formation of hollow particles. In addition, the production efficiency of the existing vibration granulation equipment is low and it does not use industrial production. Summary of the invention

[0005] The technical problem to be solved by the present invention is to provide a granulation method and system for improving the packing density of synthetic high-purity quartz sand in view of the above-mentioned deficiencies in the prior art, which can greatly reduce the hollow rate of the granulated product, thereby improving the packing density of the synthetic high-purity quartz sand product, and producing a solid particle product with fewer defects, effectively reducing the number of bubbles in downstream products, and at the same time effectively reducing the size of bubbles in downstream products.

[0006] The technical solution of the present invention to solve the above technical problems is:

[0007] According to one aspect of the present invention, there is provided a granulation method for improving the bulk density of synthetic high-purity quartz sand, comprising:

[0008] The silica sol is sprayed to form silica sol droplets, and at the same time, the silica sol droplets are microwave dried to make the silica sol droplets evenly heated inside and outside to obtain preliminarily dried gel particles;

[0009] The gel particles are placed in a drying device for drying to obtain a granulated product.

[0010] Optionally, the spray treatment uses a plurality of nozzles, and the plurality of nozzles are distributed in an array, and the size range of each nozzle is ≤2 mm.

[0011] Optionally, the size of each nozzle ranges from 0.6 to 1.6 mm.

[0012] Optionally, the size of each nozzle is 0.6 mm, 0.8 mm, 1.0 mm, 1.2 mm, 1.4 mm or 1.6 mm, and the nozzles of each size are distributed in a circular ring shape, and the rings formed by the nozzles of different sizes are arranged in concentric rings.

[0013] Optionally, the silica sol is a high-purity silica sol, wherein the purity of the silicon dioxide is

[0014] >6N.

[0015] Optionally, before spraying the silica sol, the method further comprises: adjusting the pH of the silica sol to make the pH of the silica sol be 5.0 to 10.0.

[0016] Optionally, the power of the microwave drying is adjusted according to the inlet air temperature of the spray treatment to control the inlet air temperature to be 60°C to 150°C.

[0017] Optionally, the drying treatment is carried out at a temperature of 80-170°C.

[0018] According to another aspect of the present invention, there is provided a granulation system for improving the bulk density of synthetic high-purity quartz sand, comprising a vibrating spray granulation device, a microwave heating device and a drying device, wherein:

[0019] The vibration spray granulation equipment is used to spray silica sol to form silica sol droplets, and the vibration spray granulation equipment has a plurality of nozzles, the plurality of nozzles are distributed in an array, and the size range of each nozzle is ≤2mm. At the same time, the vibration spray granulation equipment is provided with a microwave introduction port;

[0020] The microwave heating device is arranged at the microwave inlet and is used to feed microwaves into the spray granulation device to perform microwave drying on the silica sol droplets, so that the silica sol droplets are evenly heated inside and outside to obtain preliminarily dried gel particles;

[0021] The drying equipment is used to receive the gel particles and dry them to obtain granulated products.

[0022] Optionally, the size of each nozzle is 0.6 mm, 0.8 mm, 1.0 mm, 1.2 mm, 1.4 mm or 1.6 mm, and the nozzles of each size are distributed in a circular ring shape, and the rings formed by the nozzles of different sizes are arranged in concentric rings.

[0023] Beneficial effects:

[0024] The granulation method and system for improving the packing density of synthetic high-purity quartz sand of the present invention improves the conventional vibration spray granulation equipment, creatively combines the preparation of quartz sand particles by silica sol with the conventional vibration spray granulation equipment, and realizes the purpose of quartz sand granulation by using the vibration granulation principle. Compared with the prior art, it can avoid the unfavorable factors such as hollow spherical particles produced by ordinary spray granulation under the action of airflow, which leads to low packing density of quartz sand, and can greatly reduce the hollow rate of granulated products, thereby improving the packing density of synthetic high-purity quartz sand products, and obtaining solid particle products with fewer defects, effectively reducing the number of bubbles in downstream products, and at the same time can effectively reduce the size of bubbles in downstream products.

[0025] At the same time, this method can also effectively avoid the various shortcomings of the traditional quartz sand granulation method using mechanical crushing, grinding, etc., which causes uneven particle distribution, excessive subdivision, introduction of unnecessary impurities, and destruction of particle strength.

[0026] In addition, the method has high production efficiency, high feasibility, easy adjustment and control of key parameters, convenient operation, and is very suitable for industrial scale-up and mass production. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 A schematic structural diagram of a granulation system for improving the bulk density of synthetic high-purity quartz sand according to an embodiment of the present invention;

[0028] Figure 2 Schematic diagram of nozzle distribution according to an embodiment of the present invention.

[0029] In the figure: 1. material; 2. vibration mechanism; 3. drying chamber; 4. microwave inlet; 5. nozzle infusion channel; 6-vibration generator; 7-nozzle. DETAILED DESCRIPTION

[0030] In order to enable those skilled in the art to better understand the technical solution of the present invention, the technical solution of the present invention will be clearly and completely described below in conjunction with the drawings in the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work belong to the protection scope of the present invention.

[0031] Aiming at the problems that the conventional spray granulation method using silica sol as raw material in the prior art has large particle hollow ratio, low product hardness, low strength, low bulk density, etc., the present invention discloses a granulation method for improving the bulk density of synthetic high-purity quartz sand, comprising:

[0032] The silica sol is sprayed to form silica sol droplets, and at the same time, the silica sol droplets are microwave dried to make the silica sol droplets evenly heated inside and outside to obtain preliminarily dried gel particles;

[0033] The gel particles are placed in a drying device for drying to obtain a granulated product.

[0034] Accordingly, the present invention also provides a granulation system for improving the bulk density of synthetic high-purity quartz sand used in the above granulation method.

[0035] Example 1

[0036] This embodiment discloses a granulation method for improving the bulk density of synthetic high-purity quartz sand, comprising:

[0037] The silica sol is sprayed to form silica sol droplets, and at the same time, the silica sol droplets are microwave dried to make the silica sol droplets evenly heated inside and outside to obtain preliminarily dried gel particles;

[0038] The gel particles are placed in a drying device for drying to obtain a granulated product.

[0039] Specifically, if Figure 1 As shown, the spray treatment adopts a vibration spray granulation device, which has a plurality of nozzles 7 distributed in an array, and the size range of each nozzle 7 is ≤2mm.

[0040] Meanwhile, the drying chamber 3 (bottom) of the vibration spray granulation equipment is provided with a microwave inlet 4 for feeding microwaves. Compared with the conventional vibration spray granulation equipment which uses a refrigerant for cooling and granulation and is only applicable to cooling and granulation of molten materials, the present method improves the vibration spray granulation equipment and uses microwave radiation heating for drying and granulation, so that it can be suitable for silica sol granulation, and solves the problem of hollow particles existing in the conventional spray granulation method, and obtains uniform and solid quartz sand particles.

[0041] In some embodiments, the size of each nozzle 7 is in the range of 0.6 to 1.6 mm.

[0042] In some more specific embodiments, the size of each nozzle 7 is 0.6 mm, 0.8 mm, 1.0 mm, 1.2 mm, 1.4 mm or 1.6 mm, but is not limited thereto, and may also be other combinations, which are specifically adjusted according to the process requirements and will not be described one by one here. Nozzles of various sizes are distributed in circular rings. The rings formed by nozzles of different sizes are arranged in concentric rings. By arranging nozzles of different apertures according to a certain pattern, it is possible to reasonably control the production of droplets of different particle sizes, and at the same time, the particle size distribution range of the final gel particles can be adjusted, which plays a vital role in the quality control of the product.

[0043] In this embodiment, Figure 2 As shown, the ring formed by the nozzle 7 with a large size is in the outermost layer, the ring formed by the nozzle 7 with a slightly smaller size is in the inner side thereof, and so on, the ring formed by the nozzle with the smallest size is in the innermost layer.

[0044] Specifically, the sizes of the nozzles from the outside to the inside of the ring are: 1.6mm, 1.4mm, 1.0mm, 0.6mm, with an interval of 0.8mm.

[0045] In some embodiments, the silica sol is a high-purity silica sol, wherein the purity of silicon dioxide is >6N (ie, 99.9999%).

[0046] In some embodiments, in order to promote the subsequent gelation of silica sol droplets under microwave drying conditions to better obtain gel particles, the method further includes:

[0047] The pH of the silica sol is adjusted using acid or alkali, that is, the acidic silica sol is adjusted with alkali, and the alkaline silica sol is adjusted with acid, so that the pH of the silica sol is 5.0-10.0, and the silica sol after the pH adjustment is transported to the nozzle through the feeding system for granulation.

[0048] In this embodiment, the pH of the silica sol is preferably 6.0-9.0. More preferably, the pH of the silica sol is adjusted to neutral, that is, pH 7.

[0049] In some embodiments, the power of the microwave drying is adjusted according to the inlet air temperature of the spray treatment to control the inlet air temperature to be 60-150°C.

[0050] In this embodiment, the inlet air temperature is preferably controlled to be 75-120°C.

[0051] In some embodiments, the temperature of the drying process is 80-170° C. In addition, the form of the drying equipment is not limited, and it is preferred to have material rotation function and ventilation function.

[0052] In this embodiment, the temperature of the drying process is preferably 90-120°C.

[0053] The granulation method for improving the packing density of synthetic high-purity quartz sand in this embodiment improves the conventional vibration spray granulation equipment, creatively combines the preparation of quartz sand particles by silica sol with the equipment, and realizes the purpose of quartz sand granulation by the vibration granulation principle. Compared with the prior art, it can avoid the unfavorable factors such as hollow spherical particles produced by ordinary spray granulation under the action of airflow, which leads to low packing density of quartz sand, and can greatly reduce the hollow rate of the granulated product, thereby improving the packing density of the synthetic high-purity quartz sand product, and obtaining a solid particle product with fewer defects, effectively reducing the number of bubbles in downstream products, and at the same time can effectively reduce the size of bubbles in downstream products.

[0054] At the same time, this method can also effectively avoid the various shortcomings of the traditional quartz sand granulation method using mechanical crushing, grinding, etc., which causes uneven particle distribution, excessive subdivision, introduction of unnecessary impurities, and destruction of particle strength.

[0055] In addition, the method has high production efficiency, high feasibility, easy adjustment and control of key parameters, convenient operation, and is very suitable for industrial scale-up and mass production.

[0056] Example 2

[0057] This embodiment discloses a granulation system for improving the bulk density of synthetic high-purity quartz sand, which is used in the above-mentioned granulation method for improving the bulk density of synthetic high-purity quartz sand. The granulation system includes a vibrating spray granulation device, a microwave heating device and a drying device, wherein:

[0058] The vibration spray granulation equipment is used for spraying silica sol to form silica sol droplets, and the vibration spray granulation equipment has a plurality of nozzles, the plurality of nozzles are distributed in an array, and the size range of each nozzle is ≤2mm. At the same time, a microwave introduction port 4 is provided at the bottom of the vibration spray granulation equipment;

[0059] A microwave heating device is provided at the microwave inlet 4 and is used to feed microwaves into the spray granulation device to perform microwave drying on the silica sol droplets, so that the silica sol droplets are evenly heated inside and outside to obtain preliminarily dried gel particles;

[0060] The drying equipment is used for receiving the gel particles and drying them to obtain granulated products.

[0061] Specifically, if Figure 1As shown, the vibration spray granulation equipment includes a drying chamber 3, a vibration mechanism 2, a vibration generator 6 and a nozzle 7. The feeding system is connected to the nozzle 7 through the nozzle infusion channel 5, and the material 1 enters the nozzle infusion channel 5. Due to the pressure of the nozzle infusion pipeline, the material is squeezed out of the nozzle 7 to form a jet. A discharge port is provided at the bottom of the drying chamber 3 to collect gel particles. The nozzle 7 and the vibration mechanism 2 are both installed on the drying chamber 3, and the vibration mechanism 2 is connected to the nozzle 7, and the vibration generator 6 is connected to the vibration mechanism 2. After the vibration mechanism is driven by the vibration generator, the nozzle is driven to vibrate at high frequency, so that the silica sol jet sprayed from the nozzle is separated into silica sol droplets of uniform size under the dual control of high-frequency vibration and gravity.

[0062] In some embodiments, the size of each nozzle 7 is in the range of 0.6 to 1.6 mm.

[0063] In some more specific embodiments, the size of each nozzle 7 is 0.6 mm, 0.8 mm, 1.0 mm, 1.2 mm, 1.4 mm or 1.6 mm, but is not limited thereto. Other combinations are also possible, which are adjusted according to the process requirements and will not be described in detail here. Nozzles of different sizes are distributed in a circular ring shape. The rings formed by nozzles of different sizes are arranged in concentric rings.

[0064] In this embodiment, Figure 2 As shown, the ring formed by the nozzle 7 with a large size is in the outermost layer, the ring formed by the nozzle 7 with a slightly smaller size is in the inner side thereof, and so on, the ring formed by the nozzle with the smallest size is in the innermost layer.

[0065] Specifically, the sizes of the nozzles from the outside to the inside of the ring are: 1.6mm, 1.4mm, 1.0mm, 0.6mm, with an interval of 0.8mm.

[0066] Compared with the prior art, the granulation system for improving the packing density of synthetic high-purity quartz sand in this embodiment can avoid the unfavorable factors such as hollow spherical particles produced by ordinary spray granulation under the action of airflow, which leads to low packing density of quartz sand, and can greatly reduce the hollow rate of the granulated product, thereby improving the packing density of the synthetic high-purity quartz sand product, producing a solid particle product with fewer defects, effectively reducing the number of bubbles in downstream products, and at the same time effectively reducing the size of bubbles in downstream products.

[0067] At the same time, this system can also effectively avoid the various shortcomings of traditional quartz sand granulation methods such as mechanical crushing and grinding, which cause uneven particle distribution, excessive subdivision, introduction of excess impurities, and destruction of particle strength.

[0068] In addition, the system has high production efficiency, high feasibility, easy adjustment and control of key parameters, convenient operation, and is very suitable for industrial scale-up and mass production.

[0069] Example 3

[0070] This embodiment discloses a granulation method for improving the bulk density of synthetic high-purity quartz sand, the steps comprising:

[0071] 1. The granulation system described in the above embodiment is used, wherein the nozzle sizes are selected to be arranged in concentric circles of 0.6 mm, 0.8 mm, and 1.0 mm;

[0072] 2. Select acidic silica sol with a total content of 583ppb (i.e., silica purity > 99.9999%) of 12 metal elements (Al, Ca, Cr, Cu, Fe, K, Li, Mg, Mn, Na, Ni, Ti, Zn, Ba) as raw material, adjust the pH value to 8.0, and then deliver it to the nozzle through the nozzle infusion channel;

[0073] 3. Start the power of the microwave heating equipment, control the air inlet temperature to 115°C, make the silica sol material flow out from the nozzle, and drive the nozzle to vibrate at high frequency through the vibration mechanism to disperse the jet from the nozzle into silica sol droplets, which lose the solvent after being heated and dried in the drying chamber to form gel particles;

[0074] 4. The collected gel particles are transported to a rotary tube furnace through a transport pipeline;

[0075] 5. Two temperature zones of 100°C and 120°C are set in the rotary tube furnace. Air or nitrogen is introduced in reverse, so that the gel particle material is first treated in the 100°C temperature zone for 0.5 h and then in the 120°C temperature zone for 1.5 h. After drying, the material flows out of the rotary tube furnace to the collection bin to obtain quartz sand products.

[0076] After testing, the total content of 12 metal elements in the quartz sand product is 720ppb and the bulk density is 0.46g / cm3.

[0077] Example 4

[0078] This embodiment discloses a granulation method for improving the bulk density of synthetic high-purity quartz sand, the steps comprising:

[0079] 1. The granulation system described in the above embodiment is used, wherein the nozzle sizes are selected to be arranged in concentric circles of 0.8 mm, 1.0 mm, and 1.2 mm;

[0080] 2. Alkaline silica sol with a total content of 450ppb (i.e., silica purity > 99.9999%) of 12 metal elements (Al, Ca, Cr, Cu, Fe, K, Li, Mg, Mn, Na, Ni, Ti, Zn, Ba) is selected as the raw material, and after adjusting the pH value to 7.0, it is transported to the nozzle through the nozzle infusion channel;

[0081] 3. Start the power of the microwave heating equipment, control the air inlet temperature to 85°C, make the silica sol material flow out from the nozzle, and drive the nozzle to vibrate at high frequency through the vibration mechanism to disperse the jet from the nozzle into silica sol droplets, which lose the solvent after being heated and dried in the drying chamber to form gel particles;

[0082] 4. The collected gel particles are transported to a rotary tube furnace through a transport pipeline;

[0083] 5. The rotary tube furnace is provided with three temperature zones of 90°C, 105°C and 120°C, and air or nitrogen is introduced in reverse, so that the gel particle material is treated in the 90°C temperature zone for 1 hour, in the 105°C temperature zone for 2 hours, and in the 120°C temperature zone for 3 hours. After drying, the material flows out of the rotary tube furnace to the collecting bin to obtain a quartz sand product;

[0084] After testing, the total content of 12 metal elements in the quartz sand product is 843ppb and the bulk density is 0.48g / cm3.

[0085] Comparative Example 1

[0086] This comparative example discloses a granulation method for improving the bulk density of synthetic high-purity quartz sand. Compared with Example 3, it is not necessary to start the power supply of the microwave heating device and microwave drying is not performed. The steps include:

[0087] 1. The granulation system described in the above embodiment is used, wherein the nozzle sizes are selected to be arranged in concentric circles of 0.6 mm, 0.8 mm, and 1.0 mm;

[0088] 2. Select acidic silica sol with a total content of 583ppb (i.e., silica purity > 99.9999%) of 12 metal elements (Al, Ca, Cr, Cu, Fe, K, Li, Mg, Mn, Na, Ni, Ti, Zn, Ba) as raw material, adjust the pH value to 8.0, and then deliver it to the nozzle through the nozzle infusion channel;

[0089] 3. Control the air inlet temperature to 115°C, so that the silica sol material flows out from the nozzle, and the vibration mechanism drives the nozzle to vibrate at a high frequency so that the jet sprayed from the nozzle is dispersed into silica sol droplets, and the solvent is lost in the drying chamber to form gel particles;

[0090] 4. The collected gel particles are transported to a rotary tube furnace through a transport pipeline;

[0091] 5. Two temperature zones of 100°C and 120°C are set in the rotary tube furnace, and air or nitrogen is introduced in reverse, so that the gel particle material is treated in the 100°C temperature zone for 0.5 h and in the 120°C temperature zone for 1.5 h. After drying, the material flows out of the rotary tube furnace to the collection bin to obtain a quartz sand product.

[0092] After testing, the total content of 12 metal elements in the quartz sand product is 735ppb and the bulk density is 0.23g / cm3.

[0093] Comparative Example 2

[0094] This comparative example discloses a granulation method for improving the bulk density of synthetic high-purity quartz sand. Compared with Example 4, it is not necessary to start the power supply of the microwave heating device and microwave drying is not performed. The steps include:

[0095] 1. The granulation system described in the above embodiment is used, wherein the nozzle sizes are selected to be arranged in concentric circles of 0.8 mm, 1.0 mm, and 1.2 mm;

[0096] 2. Alkaline silica sol with a total content of 450ppb (i.e., silica purity > 99.9999%) of 12 metal elements (Al, Ca, Cr, Cu, Fe, K, Li, Mg, Mn, Na, Ni, Ti, Zn, Ba) is selected as the raw material, and after adjusting the pH value to 7.0, it is transported to the nozzle through the nozzle infusion channel;

[0097] 3. Control the air inlet temperature to 85°C, so that the silica sol material flows out from the nozzle, and the vibration mechanism drives the nozzle to vibrate at a high frequency so that the jet sprayed from the nozzle is dispersed into silica sol droplets, which lose the solvent after being heated and dried in the drying chamber to form gel particles;

[0098] 4. The collected gel particles are transported to a rotary tube furnace through a transport pipeline;

[0099] 5. The rotary tube furnace is provided with three temperature zones of 90°C, 105°C and 120°C, and air or nitrogen is introduced in reverse, so that the gel particle material is treated in the 90°C temperature zone for 1 hour, in the 105°C temperature zone for 2 hours, and in the 120°C temperature zone for 3 hours. After drying, the material flows out of the rotary tube furnace to the collecting bin to obtain a quartz sand product;

[0100] After testing, the total content of 12 metal elements in the quartz sand product is 812ppb and the bulk density is 0.26g / cm3.

[0101] It is to be understood that the above embodiments are merely exemplary embodiments used to illustrate the principles of the present invention, but the present invention is not limited thereto. For those of ordinary skill in the art, various modifications and improvements can be made without departing from the spirit and essence of the present invention, and these modifications and improvements are also considered to be within the scope of protection of the present invention.

Claims

1. A granulation method for improving the bulk density of synthetic high-purity quartz sand, characterized in that: include: The silica sol is sprayed to form silica sol droplets, and at the same time, the silica sol droplets are microwave dried to make the silica sol droplets evenly heated inside and outside to obtain preliminarily dried gel particles; The gel particles are placed in a drying device for drying to obtain a granulated product.

2. The granulation method for improving the bulk density of synthetic high-purity quartz sand according to claim 1, characterized in that: The spray treatment uses a plurality of nozzles, which are distributed in an array, and the size range of each nozzle is ≤2 mm.

3. The granulation method for improving the bulk density of synthetic high-purity quartz sand according to claim 2, characterized in that: The size of each nozzle ranges from 0.6 to 1.6 mm.

4. The granulation method for improving the bulk density of synthetic high-purity quartz sand according to claim 2, characterized in that: The sizes of the nozzles are 0.6 mm, 0.8 mm, 1.0 mm, 1.2 mm, 1.4 mm or 1.6 mm, respectively, and the nozzles of different sizes are distributed in a circular ring shape, and the rings formed by the nozzles of different sizes are arranged in concentric rings.

5. The granulation method for improving the bulk density of synthetic high-purity quartz sand according to claim 1, characterized in that: The silica sol is a high-purity silica sol, in which the purity of silicon dioxide is greater than 6N.

6. The granulation method for improving the bulk density of synthetic high-purity quartz sand according to claim 1, characterized in that: Before the silica sol is sprayed, the method further comprises: The pH of the silica sol is adjusted to be 5.0 to 10.

0.

7. The granulation method for improving the bulk density of synthetic high-purity quartz sand according to claim 1, characterized in that: The power of the microwave drying is adjusted according to the inlet air temperature of the spray treatment to control the inlet air temperature to be 60°C to 150°C.

8. The granulation method for improving the bulk density of synthetic high-purity quartz sand according to claim 1, characterized in that: The temperature of the drying treatment is 80-170°C.

9. A granulation system for improving the bulk density of synthetic high-purity quartz sand, characterized in that: Including vibration spray granulation equipment, microwave heating equipment and drying equipment, The vibration spray granulation equipment is used to spray silica sol to form silica sol droplets, and the vibration spray granulation equipment has a plurality of nozzles, the plurality of nozzles are distributed in an array, and the size range of each nozzle is ≤2mm. At the same time, the vibration spray granulation equipment is provided with a microwave introduction port; The microwave heating device is arranged at the microwave inlet and is used to feed microwaves into the spray granulation device to perform microwave drying on the silica sol droplets, so that the silica sol droplets are evenly heated inside and outside to obtain preliminarily dried gel particles; The drying equipment is used to receive the gel particles and dry them to obtain granulated products.

10. The granulation method for improving the bulk density of synthetic high-purity quartz sand according to claim 9, characterized in that: The sizes of the nozzles are 0.6 mm, 0.8 mm, 1.0 mm, 1.2 mm, 1.4 mm or 1.6 mm, respectively, and the nozzles of different sizes are distributed in a circular ring shape, and the rings formed by the nozzles of different sizes are arranged in concentric rings.

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