A device for deep purification of quartz sand and its application method

Abstract

A device for deep purification of quartz sand and its method of use are disclosed, relating to the field of quartz sand purification. The purification device includes a reactor with a body and a lid. The inner wall of the reactor is sequentially arranged from the inside out with a passivation film, a roughened layer, a polytetrafluoroethylene (PTFE) layer, and a stainless steel mesh. The passivation film is located on the surface of the inner wall. The stainless steel mesh is fixed to the inner wall by spaced weld points and coated with PTFE. A glass sand-holding tank is provided inside the reactor, with a gas-carrying gap between the sand-holding tank and the corrosion-resistant layer. The lid has multiple through holes for material conveying pipes to pass through and extend into the reactor. This invention achieves deep purification of static quartz sand by controlling the temperature and pressure inside the reactor, causing a breathing effect.

Description

Technical Field

[0001] This invention relates to the field of quartz sand purification, specifically to a device for deep purification of quartz sand and its usage method. Background Technology

[0002] Quartz sand is widely used due to its excellent heat resistance, corrosion resistance, abundant resources, and low price. Quartz sand is one of the most common non-metallic mineral raw materials in nature. With the rapid development of the national economy and science and technology, the application of quartz sand is no longer limited to traditional fields such as glass products and building materials where the quality requirements of raw materials are not high. It is increasingly entering the high-tech industry. For ordinary glass and building sand, the quality requirements are very low or even non-existent; however, for sand used in some electronic materials, quartz crucibles, and other fine, high-performance materials, the quality requirements of raw materials are strict, requiring high-purity and ultra-pure quartz sand with very low total impurity content.

[0003] Acid washing is a crucial step in the purification of quartz sand. In existing acid washing equipment, traditional processes mostly employ immersion purification, which involves soaking the quartz sand in a washing tank filled with acid for an extended period to remove impurities. However, immersion purification only removes impurities from the surface of the quartz sand and is not effective in removing impurities from the crevices and interior of the sand. Therefore, the purification effect needs further improvement.

[0004] The prior art discloses a Chinese invention patent with application number CN202211735125.X, entitled "A Quartz Sand Acid Quenching Purification Device and Its Usage Method". The device includes an acid quenching chamber and a material hopper located above the acid quenching chamber. The bottom wall of the acid quenching chamber is equipped with an acid pool. The falling quartz sand is heated by an annular heating mixer. The high temperature of the quartz sand will produce a gas equation effect, causing the gas in the fissures of the heated quartz sand to expand and produce a gas extrusion effect. When the quartz sand moves out of the heating zone, its temperature will drop and it will shrink. This process can make the quartz sand breathe. The heated quartz sand falls into the acid pool and comes into contact with the aqua regia in the acid pool. During the contact process, the high temperature of the quartz sand will cause the aqua regia around the quartz sand to evaporate, producing rising acid vapor. The quartz sand in the gas-absorbing state comes into contact with the rising acid vapor and will draw the acid vapor into the fissures of the quartz sand. The acid vapor will then corrode the impurities in the fissures, thereby achieving the effect of internal purification.

[0005] However, the existing purification method is to deeply purify dynamic quartz sand (i.e., quartz sand as it passes through the feeding channel). After passing through the feeding channel, the quartz sand falls into the acid quenching chamber. The quartz sand falls at a relatively fast speed, so the time for deep purification is limited. Moreover, the falling process is unidirectional and irreversible, so it is impossible to repeatedly purify the quartz sand. Therefore, the applicant provides a device and method that can deeply purify static quartz sand. Summary of the Invention

[0006] The present invention aims to provide a device for deep purification of quartz sand and a method for using it, so as to highly purify static quartz sand.

[0007] To solve the above technical problems, the specific solution adopted by the present invention is as follows: a deep purification device for quartz sand, including a reaction vessel, the reaction vessel having a vessel body and a cover, the inner wall of the vessel body being provided with a passivation film, a roughening layer, a polytetrafluoroethylene layer and a stainless steel mesh in sequence from the inside to the outside, the passivation film being located on the surface of the inner wall of the vessel body, the stainless steel mesh being fixed to the inner wall of the vessel body by spaced welding points, the surface of the stainless steel mesh being coated with polytetrafluoroethylene, a glass sand holding tank being provided in the vessel body, and a gas-carrying gap being left between the sand holding tank and the corrosion-resistant layer; the cover having multiple through holes for material conveying pipes to pass through and extend into the vessel body.

[0008] As a further optimization of the above technical solution: there are five conveying pipes, namely air inlet pipe, acid inlet pipe, water inlet pipe, water outlet pipe and exhaust pipe. The air inlet pipe, acid inlet pipe, water inlet pipe and water outlet pipe can reach the bottom of the sand holding tank, and the lower end of the exhaust pipe is higher than the upper edge of the sand holding tank.

[0009] As a further optimization of the above technical solution: the stainless steel mesh is fixed to the inner wall of the reactor by spot welding.

[0010] As a further optimization of the above technical solution: the mesh diameter of the stainless steel mesh is 20.0 to 40.0 mm, and the wire diameter is 2.0 mm to 3.2 mm.

[0011] As a further optimization of the above technical solution: the material conveying tube is made of glass.

[0012] A method for deep purification of quartz sand, the method being based on the above-mentioned purification apparatus, includes the following steps:

[0013] S1: Add quartz sand mortar into the sand container and cover it with the cap;

[0014] S2: Insert the material delivery pipe into the quartz sand mortar;

[0015] S3: Compressed air is introduced into the reactor through the feed pipe, increasing the pressure inside the reactor so that the moisture in the quartz sand slurry is discharged through another feed pipe; then drying gas is introduced into the reactor through the feed pipe to dry the quartz sand and heat the reactor.

[0016] S4: Acid solution is added into the reactor through the feed pipe. The acid solution evaporates into acid vapor to acid quench the quartz sand. At the same time, the reactor is subjected to pressure swing treatment.

[0017] S5: Reduce the pressure and temperature of the reactor, and introduce clean water to float the quartz sand;

[0018] S6: Repeat steps S3-S5 N times to complete the purification of quartz sand.

[0019] As a further optimization of the above technical solution: in step S2, the material conveying pipe is fed into the quartz sand mortar by air pressure drilling.

[0020] As a further optimization of the above technical solution: in step S3, the temperature inside the reactor after heating is 180-190℃.

[0021] As a further optimization of the above technical solution: In step S4, the pressure swing treatment specifically involves: raising the pressure inside the reactor to 0.1–0.4 MPa, maintaining the pressure for 6–20 minutes, then introducing pure water and raising the pressure to 0.6 MPa. After the water in the quartz sand flows out, drying gas is introduced into the reactor. The temperature after heating is 180–190°C. After drying the quartz sand, a vacuum is drawn inside the reactor. The temperature after depressurization is 140–160°C, and the pressure is 5000–8000 Pa.

[0022] As a further optimization of the above technical solution: the amount of acid added to the reactor is 0.5 to 2.5% of the amount of quartz sand.

[0023] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0024] This invention provides a sand-holding tank inside the reactor, with a gas-holding gap between the sand-holding tank and the inner wall of the reactor. This ensures that the internal and external gas pressures of the sand-holding tank remain consistent, preventing excessive pressure difference between the inside and outside of the sand-holding tank under high pressure conditions, which could cause rupture and affect the purification process. Furthermore, the gas-holding gap also ensures that the internal and external temperatures of the sand-holding tank remain consistent, and a stable temperature environment contributes to the smooth progress of the reaction.

[0025] This invention achieves high purification of quartz sand by controlling the temperature and pressure within the reactor to induce a breathing effect. When acid gas enters the fissures of the quartz sand, it deeply acid-quenches impurities deep within the fissures. Drying gas is introduced into the quartz sand within the reactor, drying it and simultaneously causing the fissures to expand due to heat, expelling the gas within. After drying, acid gas is introduced into the reactor while maintaining a certain pressure. The acid gas either enters or escapes from the fissures during the pressure-switching process of the reactor. Through multiple pressure-switching processes, static quartz sand can be deeply purified.

[0026] By roughening the inner wall of the reactor, its roughness is increased, and the resulting burrs help to trap more PTFE during impregnation. Fixing a stainless steel mesh to the inner wall of the reactor further enhances its corrosion resistance; besides the mesh itself being coated with PTFE, the mesh also traps PTFE in the gap between it and the inner wall, thus improving corrosion resistance. Furthermore, the flexibility of the stainless steel mesh also allows it to protect glass sand containers.

[0027] During the descent of the conveying pipe, pneumatic drilling is used. Compressed air is used to impact the mortar before the pipe is lowered, which can protect the conveying pipe and prevent it from being damaged during the descent. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the structure of the present invention;

[0029] Figure 2 This is a schematic diagram of the protective layer structure;

[0030] Figure 3 This is a top view of the lid;

[0031] Attached reference numerals: 1. Cover, 2. Reactor body, 3. Flange, 4. Feed pipe, 401. Exhaust pipe, 402. Air inlet pipe, 403. Acid inlet pipe, 404. Water inlet pipe, 405. Water outlet pipe, 5. Protective layer, 501. Stainless steel mesh, 502. Polytetrafluoroethylene layer, 503. Textured layer, 6. Sand tank, 7. Quartz sand, 8. Weld point. Detailed Implementation

[0032] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. Parts not described or disclosed in detail in the following embodiments of the present invention should be understood as prior art known or should be known by those skilled in the art.

[0033] like Figure 1 , 3 As shown, the present invention discloses a deep purification device for quartz sand, including a reaction vessel, which has a vessel body 2 and a cover 1. The vessel body 2 and the cover 1 are connected by a flange 3 so that the inside of the reaction vessel remains sealed after the cover 1 is placed on the vessel body 2.

[0034] The vessel body 2 is equipped with a sand holding tank 6, which is used to hold the quartz sand 7 to be purified. The size of the sand holding tank 6 is slightly smaller than the inner cavity of the vessel body 2, and a gas-carrying gap is left between the sand holding tank 6 and the inner wall of the vessel body 2.

[0035] The cover 1 has multiple through holes for the material conveying pipe 4 to pass through. The material conveying pipe 4 is used to insert into the sand holding tank 6 and is sealed to the cover 1. Since glass has high corrosion resistance, both the material conveying pipe 4 and the sand holding tank 6 in this embodiment are made of glass.

[0036] Both the vessel body 2 and the lid 1 are made of 316L steel, and the inner walls of both the vessel body 2 and the lid 1 are provided with a protective layer 5. For example... Figure 2 As shown, the protective layer 5 includes a stainless steel mesh 501 fixed to the inner wall of the vessel body 2 and a polytetrafluoroethylene (PTFE) layer 502 located between the stainless steel mesh 501 and the inner wall of the vessel body 2. The stainless steel mesh 501 is coated with PTFE. Through the corrosion resistance of PTFE, the reactor can be protected during the purification of quartz sand 7. Simultaneously, the stainless steel mesh 501, with its flexibility, can also protect the glass sand-containing tank 6. PTFE is a typical soft and weak polymer with low intermolecular attraction, resulting in low stiffness, hardness, and strength; therefore, its mechanical properties are relatively soft. The coating of the stainless steel mesh 501 with PTFE and the PTFE layer 502 between the stainless steel mesh 501 and the inner wall of the vessel body 2 both prevent corrosion of the inner wall of the vessel body 2 and protect the glass sand-containing tank 6.

[0037] The fabrication process of protective layer 5 is as follows: First, the inner wall of the vessel body 2 is passivated. Then, the passivated inner wall of the vessel body 2 is roughened to form a roughened layer 503, increasing the roughness of the inner wall of the vessel body 2. The specific passivation process and roughening process adopt existing technologies and will not be described in detail here. Next, a stainless steel mesh 501 is fixed to the inner wall of the vessel body 2. The mesh diameter of the stainless steel mesh 501 is 20.0-40.0 mm, and the wire diameter is 2.0 mm-3.2 mm. Finally, the inner wall of the vessel body 2 and the stainless steel mesh 501 thereon are impregnated with polytetrafluoroethylene and dried to form protective layer 5. At the location of welding point 8, the stainless steel mesh 501 is in direct contact with the inner wall of the vessel body 2. At locations other than welding point 8, a gap is formed between the stainless steel mesh 501 and the inner wall of the vessel body 2. When impregnating with polytetrafluoroethylene (PTFE), the gap between the stainless steel mesh 501 and the inner wall of the vessel 2 is covered by the stainless steel mesh 501. On the one hand, the stainless steel mesh 501 itself is covered with PTFE, and on the other hand, the stainless steel mesh 501 can lock the PTFE in the gap, thus forming a PTFE interlayer. Due to the roughening treatment of the inner wall of the vessel 2, the roughness of the inner wall of the vessel 2 is increased, which increases the degree of PTFE adhesion. The roughening protrusions can also lock the PTFE, thereby increasing the thickness of the protective layer 5, that is, the amount of PTFE adhesion, improving corrosion resistance and the protective effect on the sand tank 6.

[0038] Because the purification process of quartz sand 7 requires a specific atmospheric pressure and temperature environment, if the quartz sand 7 is directly placed in a glass sand-holding tank 6 for sealing and pressure maintenance, the glass sand-holding tank 6 will be subject to internal pressure, posing a potential risk of breakage. In this invention, the glass sand-holding tank 6 is placed inside the reactor, with a gas-filled gap between the reactor and the sand-holding tank 6. This maintains a certain pressure environment between the inner and outer walls of the sand-holding tank 6, preventing damage due to inconsistent internal and external pressures. Since both the reactor body 2 and the lid are made of stainless steel, the reactor has high pressure resistance, preventing the reactor's quality from being affected by inconsistent internal and external strengths. The flexible properties of the protective layer 5 (stainless steel mesh 501 and polytetrafluoroethylene) provide good protection for the sand-holding tank 6, ensuring the smooth progress of the purification process. In this invention, the quartz sand 7 is purified using acid vapor, resulting in some acid vapor escaping into the gas-filled gap. The protective layer 5 is used to resist the invasion of acid vapor and protect the inner wall of the reactor.

[0039] The number of through holes can be set according to the size of the reactor. In this embodiment, there are five through holes for the feed pipes 4 to pass through, and the five through holes are distributed at intervals on the cover 1, so the corresponding number of feed pipes 4 is also five. The five feed pipes 4 are respectively the air inlet pipe 402, acid inlet pipe 403, water inlet pipe 404, water outlet pipe 405, and exhaust pipe 401. The depth of the feed pipes 4 into the reactor is controllable. In order to maintain a better purification effect, the air inlet pipe 402, acid inlet pipe 403, water inlet pipe 404, and water outlet pipe 405 can reach the bottom of the sand tank 6, so as to facilitate the introduction of reactants and corresponding gases into the sand tank 6 through the feed pipes 4, and the discharge of wastewater and waste gas after the reaction through the feed pipes 4. The lower end of the exhaust pipe 401 is higher than the upper edge of the sand tank 6. After the feed pipes 4 are inserted into the sand tank 6, the feed pipes 4 and the exhaust holes are sealed together. This is the prior art and will not be described in detail here.

[0040] It should be noted that the feed pipes 4 used for supplying water, air, and acid to the reactor can be set up separately as described in this embodiment, or different material sources can be connected sequentially through a single feed pipe 4 as the purification process proceeds. That is, water, air, or acid sources can be connected sequentially through a single feed pipe 4 according to the actual application scenario to complete the operation of supplying water, air, or acid. However, it is necessary to ensure that there is at least one water outlet pipe 405 and one exhaust pipe 401.

[0041] This invention discloses a method for purifying high-purity quartz sand. The method, based on the aforementioned purification apparatus, includes the following steps:

[0042] S1: Add quartz sand mortar into the sand tank 6, cover the cap 1, and keep the connection between the cap 1 and the vessel body 2 sealed.

[0043] S2: Insert the material conveying pipe 4 into the quartz sand mortar;

[0044] Specifically, the feed pipe 4 is inserted into the quartz sand slurry using pneumatic drilling. Pneumatic drilling involves introducing compressed air into the quartz sand slurry through the feed pipe 4 as it descends. The compressed air displaces the quartz sand slurry, creating space for the feed pipe 4 to descend further. The feed pipe 4 can then penetrate deep into the quartz sand slurry without encountering significant resistance. Since the feed pipe 4 is made of glass, this pneumatic drilling method protects it from damage during its descent. The pneumatic drilling method simulates well drilling by sequentially lowering the feed pipe 4 until it is inserted into the bottom of the sand-collecting tank 6. The lower end of the feed pipe 4 is located at the bottom of the quartz sand slurry. The feed pipe 4 is used to introduce appropriate materials into the sand-collecting tank 6 or to discharge waste materials after the reaction. One feed pipe 4 is used to discharge gas from the reactor; therefore, this feed pipe 4 is located at the top of the quartz sand slurry. The power to control the lifting of the feed pipe 4 can be achieved through a vertical lifting mechanism. For example, if the hollow tube is fixed on the slider, the vertical lifting of the slider can be achieved through a slide rail, cylinder, etc. The specific structure will not be described in detail.

[0045] S3: Compressed air is introduced into the reactor through the feed pipe 4, increasing the pressure inside the reactor body 2 so that the moisture in the quartz sand slurry is discharged through another feed pipe 4; then, drying gas is introduced into the reactor through the feed pipe 4 to dry the quartz sand 7 and heat up the reactor.

[0046] Specifically, compressed air is introduced into the reactor through the air inlet pipe 402. The introduction of compressed air increases the pressure inside the reactor, causing the quartz sand slurry in the sand-holding tank 6 to shift under pressure. At this time, the water outlet pipe 405 remains open, allowing the moisture in the quartz sand slurry to overflow from the water outlet pipe 405. It should be noted that a filter screen is installed at the lower end of the water outlet pipe 405 to intercept the quartz sand 7, preventing it from flowing out with the water outlet pipe 405. After the moisture in the quartz sand 7 has flowed out, drying gas is introduced into the reactor, causing the moisture on the surface of the quartz sand 7 to heat up and form water vapor. The water vapor rises and is discharged through the exhaust pipe 401, completing the drying of the quartz sand 7. The temperature after heating is 180-190℃. After drying the quartz sand 7, a vacuum is drawn into the reactor, and the temperature after depressurization is 140-160℃, with a pressure of 5000-8000 Pa.

[0047] S4: Acid solution is dripped into the reactor through the feed pipe 4. The acid solution evaporates into acid vapor to acid quench the quartz sand 7. The added acid solution is hydrochloric acid first, with an acid concentration of 30% to 36%; then nitric acid is added, with an acid concentration of 36% to 48%. Since acid vapor is used to acid wash the quartz sand 7 in this invention, a relatively small amount of acid solution is needed to effectively purify the quartz sand 7. The amount of acid solution added is 0.5% to 2.5% of the amount of quartz sand 7.

[0048] After the acid solution is added to the reactor, the reactor is subjected to pressure-switching treatment. The pressure inside the reactor is increased to 0.1–0.4 MPa and maintained for 6–20 minutes. Then, pure water is introduced, and the pressure is increased to 0.6 MPa. At this time, the water outlet pipe 405 is kept open, and the water in the quartz sand slurry will overflow from the water outlet pipe 405. It should be noted that a filter screen is installed at the lower end of the water outlet pipe 405 to intercept the quartz sand 7 and prevent it from flowing out with the water outlet pipe 405. After the water in the quartz sand 7 flows out, drying gas is introduced into the reactor, so that the water on the surface of the quartz sand 7 is heated and turns into water vapor. The water vapor rises and is discharged from the exhaust pipe 401 to complete the drying of the quartz sand 7. The temperature after heating is 180–190℃. After the quartz sand 7 is dried, the reactor is evacuated. The temperature after depressurization is 140–160℃ and the pressure is 5000–8000 Pa.

[0049] Repeat this process 2 to 3 times.

[0050] S5: Reduce the pressure and temperature of the reactor. The temperature after the pressure reduction and cooling is 90℃ and the pressure is 0.1MPa. Then, clean water is introduced through the water inlet pipe 404 to float the quartz sand 7. The impurities quenched by acid are separated from the quartz sand 7 by the flotation, thereby improving the purity of the quartz sand 7.

[0051] S6: Repeat steps S3-S5 N times to complete the purification of quartz sand 7. After the final flotation, drain and dry the quartz sand 7 in the same way as in S3 to obtain high-purity quartz sand 7. According to the deep purification method of this invention, steps S3-S5 are generally repeated four times, and then the flotated quartz sand 7 is drained and dried to complete the deep purification of quartz sand 7. Then, the feed pipe 4 is removed from the reactor, and the purified quartz sand is removed from the reactor.

[0052] In this invention, after adding the quartz sand to be purified, the cap 1 is closed, and then the feed pipe 4 is installed. After purification is completed, the feed pipe 4 is removed first, and then the cap 1 is opened. Therefore, the feed pipe 4 will not interfere with the closing or opening of the cap 1 during the reaction process. The cap 1 can be moved horizontally to open or close the reactor, which enhances the convenience of operation and facilitates the entry and exit of quartz sand from the reactor.

[0053] This invention achieves deep purification of quartz sand 7 by controlling the temperature and pressure within the reactor to induce a breathing effect. When acid gas enters the fissures of the quartz sand 7, it deeply acid-quenches impurities deep within the fissures. Drying gas is introduced into the quartz sand 7 within the reactor, both to dry the sand and to cause the fissures to expand due to heat, expelling the gas within. After drying, acid gas is introduced into the reactor while maintaining a certain pressure. The acid gas enters or escapes from the fissures of the quartz sand 7 during the pressure-switching process, purifying the impurities within the fissures. Through this deep purification method, the purity of the quartz sand 7 can reach 99.999%, and the use of acid gas for acid quenching significantly reduces the amount of acid used.

[0054] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for deep purification of quartz sand, characterized in that: This method is based on a deep purification device for quartz sand. The quartz sand deep purification device includes a reactor, which has a vessel body (2) and a cover (1). The inner wall of the vessel body (2) is provided with a passivation film, a roughened layer, a polytetrafluoroethylene layer (502) and a stainless steel mesh (501) from the inside to the outside. The passivation film is located on the surface of the inner wall of the vessel body (2). The stainless steel mesh (501) is fixed to the inner wall of the vessel body (2) by spaced welding points (8). The surface of the stainless steel mesh (501) is coated with polytetrafluoroethylene. A glass sand-holding tank (6) is provided inside the vessel body (2). A gas-holding gap is left between the sand-holding tank (6) and the corrosion-resistant layer. The cap (1) has multiple through holes through which the material conveying pipes (4) pass and extend into the vessel body (2); There are five conveying pipes (4), namely air inlet pipe (402), acid inlet pipe (403), water inlet pipe (404), water outlet pipe (405) and exhaust pipe (401). The air inlet pipe (402), acid inlet pipe (403), water inlet pipe (404) and water outlet pipe (405) can reach the bottom of the sand holding tank (6), and the lower end of the exhaust pipe (401) is higher than the upper edge of the sand holding tank (6). The mesh diameter of stainless steel mesh (501) is 20.0~40.0mm, and the wire diameter is 2.0mm~3.2mm; The stainless steel mesh (501) is fixed to the inner wall of the vessel body (2) by spot welding. The stainless steel mesh (501) at the location of the welding point (8) is in direct contact with the inner wall of the vessel body (2), and a gap is formed between the stainless steel mesh (501) and the inner wall of the vessel body (2) at the location outside the welding point (8). The method for deep purification of quartz sand includes the following steps: S1: Add quartz sand mortar into the sand container (6) and close the cover (1); S2: Insert the material conveying pipe (4) into the quartz mortar; S3: Compressed air is introduced into the reactor through the feed pipe (4), and the pressure inside the reactor body (2) increases so that the water in the quartz sand (7) slurry is discharged through another feed pipe (4); then drying gas is introduced into the reactor through the feed pipe (4) to dry the quartz sand (7) and heat the reactor. S4: Acid solution is added into the reactor through the feed pipe (4). The acid solution evaporates into acid vapor to acid quench the quartz sand (7) and at the same time, the reactor is subjected to pressure transformation treatment. S5: Reduce the pressure and temperature of the reactor, and introduce clean water to float the quartz sand (7); S6: Repeat steps S3-S5 N times to complete the purification of quartz sand (7); The material conveying pipe (4) is fed into the quartz sand mortar by air pressure drilling; In step S4, the pressure change process is as follows: the pressure inside the reactor is increased to 0.1~0.4MPa, and the pressure is maintained for 6~20 minutes. Then, pure water is introduced and the pressure is increased to 0.6 MPa. After the water in the quartz sand (7) flows out, drying gas is introduced into the reactor. The temperature after heating is 180~190℃. After drying the quartz sand (7), the reactor is evacuated. The temperature after decompression is 140~160℃ and the pressure is 5000~8000Pa. The acid solution added is hydrochloric acid first, with an acid concentration of 30%~36%; then nitric acid is added, with an acid concentration of 36%~48%; the amount of acid added is 0.5~2.5% of the amount of quartz sand. After the acid solution is added to the reactor, the reactor is subjected to pressure swing treatment.

2. The method for deep purification of quartz sand according to claim 1, characterized in that: The material conveying pipe (4) is made of glass.

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