CN117401686A - Quartz sand microwave purification device, purification method and high-purity quartz sand - Google Patents

Abstract

The invention provides a quartz sand microwave purification device, a purification method and high-purity quartz sand. The device comprises a microwave generating mechanism, a material placing mechanism and a shell, wherein an ellipsoidal cavity is formed by enclosing the inner wall of the shell, the device comprises an upper shell and a lower shell which are detachably connected, the upper shell is provided with an air outlet pipe and a feeding pipe which extend into the ellipsoidal cavity, and a material placing mechanism positioning piece is arranged at the position, corresponding to a long half shaft of the ellipsoidal cavity, of the lower shell; the microwave generating mechanism stretches into the ellipsoidal cavity from the position of the upper shell corresponding to the long half shaft of the ellipsoidal cavity, and the microwave generating position of the microwave generating mechanism is positioned at the upper focus of the ellipsoidal cavity; the material placing mechanism comprises a material carrying disc with an opening at the bottom and a storage groove connected with the material carrying disc and positioned below the material carrying disc. According to the invention, through the design of matching the ellipsoidal cavity double-focus structure with the microwave generation position of the microwave generation mechanism, the material carrying tray, the material storage groove and the like, the microwave-water quenching-acid washing integration is realized, the microwave utilization rate and the heating efficiency are improved, the purification efficiency is improved, the energy consumption is low, and the cost is low.

Description

A quartz sand microwave purification device, purification method and high-purity quartz sand

Technical Field

The invention relates to the technical field of quartz sand purification, and in particular to a quartz sand microwave purification device, a purification method and high-purity quartz sand.

Background Art

High-purity quartz sand is the basic raw material for high-end manufacturing industries such as photovoltaics, semiconductors, communications, and national defense and military industries. With the rapid development of these application fields, high-quality and high-purity natural quartz resources are in short supply, and deep purification of ordinary low-grade natural quartz ores has become the mainstream direction for obtaining high-purity quartz sand. However, ordinary natural quartz ores are affected by magma movement and geological conditions, and the impurity content and distribution, fluid inclusion types, and chemical elements are different. The quality of quartz ores in different regions or even in the same region is not uniform. Under a certain purification cycle, the quality of quartz sand obtained after purification by existing purification technology is different. Many of the purified quartz sands cannot meet the use requirements of high-end manufacturing industries such as photovoltaics, semiconductors, communications, and national defense and military industries. In order to meet the required requirements, it is necessary to extend the purification cycle, which consumes a lot of energy and has high costs. Even if the purification cycle is extended, it is still impossible to obtain quartz sand that meets the use requirements of high-end manufacturing industries such as photovoltaics, semiconductors, communications, and national defense and military industries. Therefore, there is an urgent need in the art for a quartz sand purification method with low energy consumption, low cost and high efficiency, and a purification device that can implement the purification method.

Summary of the invention

The invention provides a quartz sand microwave purification device, a purification method and high-purity quartz sand, so as to solve the problems of high energy consumption, high cost and low purification efficiency in the existing quartz sand purification method.

On the one hand, the present invention provides a quartz sand microwave purification device, comprising a microwave generating mechanism, a feeding mechanism and a shell, the inner wall of the shell forms an ellipsoidal cavity, the shell comprises an upper shell and a lower shell, the upper shell and the lower shell are detachably connected, the upper shell is provided with an air outlet pipe extending into the ellipsoidal cavity and a plurality of feeding pipes extending into the ellipsoidal cavity, the lower shell is provided with a feeding mechanism positioning piece at a position corresponding to the long semi-axis of the ellipsoidal cavity; the microwave generating mechanism extends into the ellipsoidal cavity from the position of the upper shell corresponding to the long semi-axis of the ellipsoidal cavity, and the microwave generating position of the microwave generating mechanism is located at the upper focus of the ellipsoidal cavity; the feeding mechanism comprises a loading tray and a storage trough located below the loading tray, the loading tray is connected to the storage trough, and an opening is provided at the bottom of the loading tray.

Compared with the prior art, the present invention has the following beneficial effects: the shell of the purification device of the present invention has an ellipsoidal cavity, and through the dual-focus structure of the ellipsoidal cavity, the microwave generating position is set at the upper focus of the ellipsoidal cavity in coordination with the microwave generating position of the microwave generating mechanism. After the microwave generating mechanism is started, the microwave is emitted from the microwave generating position of the upper focus, and after being reflected in the ellipsoidal cavity, it will eventually converge to the lower focus position of the ellipsoidal cavity, thereby realizing high-frequency, high-power, and low-loss microwave transmission. The microwave receiving rate at the lower focus is close to 100%. Based on the specific wavelengths of different microwave frequencies, microwave plasma spherical areas of different sizes are formed with the lower focus as the center. In coordination with the position of the loading tray, the microwave plasma spherical area covers the material holding area of the loading tray, and the quartz sand in the loading tray is heated with the greatest efficiency, so that the quartz sand is rapidly heated. The temperature is raised to improve the microwave utilization rate and heating efficiency, with low energy consumption and low cost. On this basis, with the help of the selective heating effect of microwave plasma, the temperature and pressure of impurities such as gas-liquid inclusions in quartz sand rise sharply, causing the impurities to burst or generate microcracks at the interface between the impurities and the quartz sand matrix, so that the quartz sand state meets the water purification requirements in a very short time. With the design of the storage tank (the storage tank can store acid solution), the quartz sand with microcracks falls into the acid solution stored in the storage tank, and the microcracks of impurities such as gas-liquid inclusions are extended through water quenching, and the impurities in the gas-liquid inclusions are removed through acid washing, which greatly saves time and cost, realizes the integration of microwave-water quenching-acid washing, and improves the purification efficiency. It can also be combined with chlorination treatment, and chlorination treatment is performed after the quartz sand is rapidly heated with the help of microwaves to improve the purification effect.

In some embodiments of the present invention, the open ends of the upper shell and the lower shell are both provided with flanges, and the upper shell and the lower shell are connected by means of bolt and nut structures through the mounting openings on the flanges; and/or, one end of the feed pipe extending into the ellipsoidal cavity faces the lower focus of the ellipsoidal cavity; and/or, the positioning piece of the feeding mechanism is in the shape of a groove, and the shape of the positioning piece of the feeding mechanism matches the outer surface of the storage tank, and the storage tank can be embedded in the positioning piece of the feeding mechanism. The flange facilitates the connection and disassembly of the upper shell and the lower shell; the feed pipe faces the lower focus of the ellipsoidal cavity, which facilitates the control of the input direction of the material, facilitates the passage of quartz sand into the loading tray, and facilitates the full contact between the quartz sand and the introduced gas. The positioning piece of the feeding mechanism facilitates the positioning of the feeding mechanism.

In some embodiments of the present invention, the microwave generating mechanism adopts a 2.45GHz solid-state microwave source or a 915MHz solid-state microwave source; when the material placing mechanism is placed on the material placing mechanism positioning member by means of the storage tank, the material placing mechanism is located on the long semi-axis of the ellipsoidal cavity; and when the microwave generating mechanism adopts a 2.45GHz solid-state microwave source, the distance between the upper surface of the material loading plate and the lower focus of the ellipsoidal cavity is 30 to 45mm, and 5cm≤the diameter of the upper end surface of the material loading plate≤10cm; when the microwave generating mechanism adopts a 915MHz solid-state microwave source, the distance between the upper surface of the material loading plate and the lower focus of the ellipsoidal cavity is 75 to 125mm, and 5cm≤the diameter of the upper end surface of the material loading plate≤15cm. Using a 2.45GHz solid-state microwave source or a 915MHz solid-state microwave source, the microwave heating effect is better and more conducive to the rapid heating of quartz sand. When a 2.45GHz solid-state microwave source is used, the corresponding wavelength is 12.24cm, and the diameter of the microwave plasma sphere centered on the lower focus is Dmax=λ/2=6.12cm. The distance between the upper surface of the loading plate and the lower focus of the ellipsoidal cavity is designed to be 30-45mm while satisfying 5cm≤the diameter of the upper end face of the loading plate≤10cm, so that the microwave plasma spherical area can cover the loading plate holding area, and the quartz sand in the loading plate can be heated with maximum efficiency. When a 915MHz solid-state microwave source is used, the corresponding wavelength is 33cm, and the diameter of the microwave plasma sphere centered on the lower focus is Dmax=λ/2=16.5cm. The distance between the upper surface of the loading plate and the lower focus of the ellipsoidal cavity is designed to be 75-125mm while satisfying 5cm≤the diameter of the upper end face of the loading plate≤15cm, so that the microwave plasma spherical area can cover the loading plate holding area, and the quartz sand in the loading plate can be heated with maximum efficiency.

In some embodiments of the present invention, the loading tray is detachably connected to the storage tank, a loading tray connection seat is provided at intervals on the outer surface of the loading tray, a storage tank connection seat is provided at intervals on the upper part of the storage tank, and both the loading tray connection seat and the storage tank connection seat are provided with mounting through holes, and the loading tray and the storage tank can be connected by elastic members of different specifications via the mounting through holes. The loading tray and the storage tank are detachably connected, which facilitates the replacement of elastic members of different lengths to adjust the distance between the loading tray and the storage tank, thereby achieving the adjustment of the distance between the upper surface of the loading tray and the lower focus of the ellipsoidal cavity.

In some embodiments of the present invention, a feeding channel is also connected below the loading tray, and the feeding channel is connected to the opening at the bottom of the loading tray, and the length of the feeding channel is ≤20cm; an opening switch is provided at the opening, and a vibration mechanism is provided on the feeding channel. The feeding channel provides a channel for the quartz sand to fall into the storage tank, preventing the quartz sand from falling directly from the opening, causing the quartz sand to scatter and be unable to fall into the storage tank; the length of the feeding channel is ≤20cm, which can prevent the long falling distance from causing excessive cooling and affecting the water pickling effect; the opening switch can control whether the opening is opened or not, and it is opened after the quartz sand is heated to the required temperature, which is convenient for controlling the temperature of the quartz sand when falling; the vibration mechanism provides the loading tray with a vibration function, and the quartz sand is evenly spread on the loading tray and falls along the way through vibration, so as to control the time and temperature of the quartz sand after microwave plasma treatment.

On the other hand, the present invention also provides a quartz sand microwave purification method, comprising the following steps: S1, crushing-screening treatment: crushing and screening the quartz ore to obtain quartz raw sand of a preset size; S2, initial purification treatment: initially purifying the quartz raw sand by a purification method including magnetic separation, flotation, and acid washing; S3, microwave-water purification-acid washing integrated purification treatment: using any of the above-mentioned quartz sand microwave purification devices, placing an acid solution in a storage tank, placing a feeding mechanism on a feeding mechanism positioning member of a lower shell, closing the upper shell and the lower shell to make the ellipsoidal cavity in a sealed state, evacuating the ellipsoidal cavity through an air outlet pipe until the air pressure in the ellipsoidal cavity reaches a first preset air pressure, introducing HCl gas into the ellipsoidal cavity through a feed pipe until the air pressure in the ellipsoidal cavity reaches a second preset air pressure, and starting the microwave generator. S4, microwave-chlorination purification treatment: using another quartz sand microwave purification device described in any one of the above items, placing the feeding mechanism on the feeding mechanism positioning member of the lower shell, closing the upper shell and the lower shell to make the ellipsoidal cavity in a sealed state, and after vacuuming the ellipsoidal cavity through the air outlet pipe until the air pressure in the ellipsoidal cavity reaches a third preset air pressure, extracting the gas in the ellipsoidal cavity from the air outlet pipe of the quartz sand microwave purification device applied in S3, and passing the extracted gas into the ellipsoidal cavity through any feeding pipe of the quartz sand microwave purification device applied in S4, and at the same time, introducing O into the ellipsoidal cavity through other feeding pipes. ₂ and Cl ₂ until the gas pressure in the ellipsoidal cavity reaches a fourth preset gas pressure, the microwave generating mechanism is started, and the extracted gas, O ₂ , Cl ₂ and the quartz sand obtained after the previous purification step are respectively introduced into the ellipsoidal cavity through different feeding pipes, the quartz sand falls into the loading tray and is heated by the microwave generating mechanism, and then falls into the storage tank through the opening, completing the microwave-chlorination purification treatment.

Compared with the prior art, the present invention has the following beneficial effects: the microwave purification method for quartz sand of the present invention uses the microwave purification device for quartz sand of the present invention in both the microwave-water purification-acid washing integrated purification treatment and the microwave-chlorination purification treatment stage, so that the temperature of the quartz sand is rapidly increased. In the microwave-water purification-acid washing integrated purification treatment stage, with the help of the selective heating effect of microwave plasma, the temperature and pressure of impurities such as gas-liquid inclusions in the quartz sand rise sharply, and then thermal explosion occurs, or the difference in thermal expansion coefficient with the quartz sand matrix causes microcracks to be generated between the impurities and the matrix interface, so that the quartz sand reaches the water state in a very short time. According to the requirements of purification, in conjunction with the design of the storage tank, the prepared quartz sand falls into the acid solution stored in the storage tank, and the microcracks generated at the interface are extended by water quenching, and the impurities in the gas-liquid inclusions are removed by pickling, with high purification efficiency and high degree of purification, and the quartz sand after treatment has higher purity; in the microwave-chlorination purification stage, the quartz sand can also be rapidly heated, and then the impurities are purified by chlorination with the help of the reaction gas, and the reaction gas can use the gas in the ellipsoidal cavity after the integrated purification treatment of microwave-water purification-pickling is completed, which can be reused to reduce costs, and has high purification efficiency and high degree of purification, and the quartz sand after treatment has higher purity.

The present invention introduces a chlorinating agent (HCl gas), which can be combined with impurities in quartz sand to convert them into gas phase or condensed phase in the microwave-water scavenging-pickling integrated purification treatment stage, thereby separating impurities from quartz sand, preliminarily removing a certain amount of metal impurities, preparing for the next step of water scavenging and pickling, and improving removal efficiency and probability; at the same time, HCl gas can be used as one of the working gases in the next stage of microwave-chlorination purification treatment, thereby reducing costs; in addition, the quartz sand sample that is insulated after microwave roasting does not need to be transferred out, avoiding heat loss, and directly undergoes water quenching and pickling treatment, ensuring the quenching effect, which is conducive to the extension of cracks, thereby improving the efficiency of pickling. In the microwave-chlorination purification treatment stage, compared with a solid chlorine source, the introduction of a gaseous chlorine source can completely wrap the surface of quartz sand, greatly increasing the contact area between the chlorine source and the impurities in the quartz sand, and is more conducive to condensing with the impurity phase to separate the impurity phase from the quartz sand matrix, thereby improving the efficiency of chlorination roasting. The purification method of the present invention is suitable for purifying quartz ores of uneven quality in different regions and the same region. Compared with the prior art, the purification effect is good, and the purified quartz sand can obtain better purity.

In some embodiments of the present invention, the preset size is 50-425 μm; and/or, the acid solution in S3 is a mixed aqueous solution of hydrochloric acid and nitric acid, wherein the weight ratio of hydrochloric acid to nitric acid in the acid solution is 1:(1-1.5), the concentration of hydrochloric acid is 1.5-2.0 mol/L, the concentration of nitric acid is 1.5-2.0 mol/L, and the weight ratio of quartz sand falling into the storage tank to the acid solution is 1:(3-8); and/or, when S3-S4 is introduced into the quartz sand obtained after the previous step of purification, the loading tray is vibrated by a vibration mechanism on a feeding channel connected to the bottom of the loading tray and connected to the opening at the bottom of the loading tray; and/or, the first preset air pressure and the third preset air pressure are both ≤1×10 ^-2 Pa, the second preset air pressure is 13333-34666Pa, and the fourth preset air pressure is 6666.5-23000Pa. Quartz sand screening to a size of 50-425 μm is conducive to improving the purification efficiency and purification effect of the microwave-water purification-pickling integrated purification treatment and microwave-chlorination purification treatment stages. The acid solution is a mixed aqueous solution of hydrochloric acid and nitric acid. The strong oxidizing property of nitric acid causes the metal impurities on the surface of the quartz sand to react with it to form nitrates. The nitrates of metal ions have a high solubility in water. After a long period of pickling, the impurity nitrates can be separated from the quartz sand. In addition, hydrochloric acid can provide a strong acidic environment and remove Fe in the quartz sand at the same time. The combination of the two acids can not only avoid damage to the quartz sand, but also improve the impurity removal effect. The design of the acid solution and the amount of quartz sand and the acid solution can fully guarantee the pickling effect and efficiency of the quartz sand. Excessive acid solution will cause unnecessary additional costs, and too little acid solution will result in poor pickling effect. The vibration mechanism provides a vibration function, which realizes the uniform paving and falling of the quartz sand on the loading tray through vibration, so as to control the time and temperature of the quartz sand after microwave plasma treatment/chlorination treatment.

In some embodiments of the present invention, when the microwave generating mechanism adopts a 2.45 GHz solid-state microwave source, the flow rate of HCl gas introduced into S3 is 0.1 to 1.5 L/min, the speed of introducing the quartz sand obtained after the previous step of purification is 0.5 to 2.5 kg/min, and the quartz sand is heated to 950 to 1200°C by the microwave generating mechanism; the flow ratio of _O2 introduced into S4 to the gas introduced into the ellipsoidal cavity of S3 is (0.1 to 2.4):100, the flow ratio of _Cl2 introduced to the gas introduced into the ellipsoidal cavity of S3 is (3 to 20):100, the speed of introducing the quartz sand obtained after the previous step of purification is 0.5 to 2.5 kg/min, and the quartz sand is heated to 800 to 1000°C by the microwave generating mechanism.

In some embodiments of the present invention, when the microwave generating mechanism adopts a solid-state microwave source of 915 MHz, the flow rate of HCl gas introduced into S3 is 0.35-6.5 L/min, the speed of introducing the quartz sand obtained after the previous step of purification is 1.5-10 kg/min, and the quartz sand is heated to 950-1200°C by the microwave generating mechanism; the flow ratio of _O2 introduced into S4 to the gas introduced into the ellipsoidal cavity of S3 is (0.1-2.4):100, the flow ratio of _Cl2 introduced to the gas introduced into the ellipsoidal cavity of S3 is (3-20):100, the speed of introducing the quartz sand obtained after the previous step of purification is 1.5-10 kg/min, and the quartz sand is heated to 800-1000°C by the microwave generating mechanism.

When the present invention adopts a 2.45 GHz solid-state microwave source or a 915 MHz solid-state microwave source, and performs microwave-water purification-acid washing integrated purification treatment and microwave-chlorination purification treatment stages with the above-mentioned gas flow rate, quartz sand introduction speed, heating temperature, reaction gas flow ratio, etc., the microwave has a better heating effect on the quartz sand, the contact timing between the quartz sand and the reaction gas, acid solution, etc. is better, and it is more conducive to the purification of the quartz sand.

On the other hand, the present invention also provides a high-purity quartz sand, which is purified according to any of the above-mentioned quartz sand microwave purification methods. The high-purity quartz sand of the present invention has high purity and meets the use requirements of high-end manufacturing industries such as photovoltaics, semiconductors, communications, and national defense.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings required for use in the embodiments of the present invention will be described below.

FIG1 is a perspective view of a quartz sand microwave purification device according to an embodiment of the present invention, wherein a material placement mechanism positioning member, a material loading tray connection seat, a storage tank connection seat and an elastic member are not shown;

2 is a cross-sectional view of a quartz sand microwave purification device according to an embodiment of the present invention, taken along a plane where its long semi-axis and the center of a feed pipe are located;

FIG3 is a flow chart of a method for microwave purification of quartz sand according to an embodiment of the present invention, wherein a schematic diagram of a microwave purification device for quartz sand according to an embodiment of the present invention is shown in the microwave-water purification-acid washing integrated purification process and the microwave-chlorination purification process;

Figure 4 is a comparison diagram of quartz sand purified by a quartz sand microwave purification method according to an embodiment of the present invention and unpurified quartz sand after heating and bubbling, wherein Figure 4(a) is a diagram of the bubbling state of unpurified quartz sand after heating, and Figure 4(b) is a diagram of the bubbling state of quartz sand purified by a quartz sand microwave purification method according to an embodiment of the present invention after heating.

DETAILED DESCRIPTION

In order to make the objectives, technical solutions and advantages of the present invention more clear, various aspects of the present invention will be described in detail in conjunction with specific embodiments below, but these specific embodiments are only used to illustrate the present invention and do not constitute any limitation on the scope of protection and essential content of the present invention.

Example 1

The present embodiment provides a quartz sand microwave purification device, as shown in Fig. 1-2, comprising a microwave generating mechanism 1, a feeding mechanism 2 and a shell 3. The inner wall of the shell 3 forms an ellipsoidal cavity, and the shell 3 comprises an upper shell 31 and a lower shell 32, which are detachably connected, and the upper shell 31 is provided with an air outlet pipe 311 extending into the ellipsoidal cavity and a plurality of feeding pipes 312 extending into the ellipsoidal cavity, and the lower shell 32 is provided with a feeding mechanism positioning member 321 corresponding to the position of the long semi-axis of the ellipsoidal cavity. In the present embodiment, the number of feeding pipes 312 is not limited and can be set as needed; preferably, valve switches are provided on the air outlet pipe 311 and the feeding pipe 312 to control the opening and closing of the air outlet pipe 311 and the feeding pipe 312; preferably, one end of the feeding pipe 312 extending into the ellipsoidal cavity faces the lower focus of the ellipsoidal cavity. In this embodiment, the detachable connection method of the upper shell 31 and the lower shell 32 is not restricted. For example, the open ends of the upper shell 31 and the lower shell 32 are provided with flanges 33, and the upper shell 31 and the lower shell 32 are connected by means of bolt and nut structures through the mounting openings on the flanges 33; preferably, a seal can be provided at the connection.

In this embodiment, the microwave generating mechanism 1 extends into the ellipsoidal cavity from the position of the upper shell 31 corresponding to the long semi-axis of the ellipsoidal cavity, and the microwave generating position 11 of the microwave generating mechanism 1 is located at the upper focus of the ellipsoidal cavity. In this embodiment, the specific structure of the microwave generating mechanism 1 is not limited, and commercially available products can be used. In this embodiment, preferably, the microwave generating mechanism 1 uses a 2.45 GHz solid-state microwave source or a 915 MHz solid-state microwave source.

In this embodiment, the material placement mechanism 2 includes a material loading tray 21 and a storage tank 22 located below the material loading tray 21, the material loading tray 21 is connected to the storage tank 22, and an opening is provided at the bottom of the material loading tray 21. In this embodiment, preferably, the material placement mechanism positioning member 321 is in the shape of a groove, the shape of the material placement mechanism positioning member 321 matches the outer surface of the storage tank 22, and the storage tank 22 can be embedded in the material placement mechanism positioning member 321.

In this embodiment, when the material placement mechanism 2 is placed on the material placement mechanism positioning member 321 by means of the storage tank 22, the material placement mechanism 2 is located on the long semi-axis of the ellipsoidal cavity, and the material loading plate 21 is located below the lower focus. When the microwave generating mechanism 1 adopts a 2.45GHz solid-state microwave source, the distance H between the upper surface of the material loading plate 21 and the lower focus of the ellipsoidal cavity is 30 to 45mm, and 5cm≤the diameter of the upper end surface of the material loading plate≤10cm; when the microwave generating mechanism 1 adopts a 915MHz solid-state microwave source, the distance H between the upper surface of the material loading plate 21 and the lower focus of the ellipsoidal cavity is 75 to 125mm, and 5cm≤the diameter of the upper end surface of the material loading plate≤15cm.

In this embodiment, the loading tray 21 and the storage tank 22 are detachably connected, the outer surface of the loading tray 21 is provided with a loading tray connection seat 211, and the upper part of the storage tank 22 is provided with a storage tank connection seat, and the loading tray connection seat 211 and the storage tank connection seat are provided with mounting through holes, and the loading tray 21 and the storage tank 22 can be connected by elastic members 23 of different specifications through the mounting through holes. In this embodiment, the elastic members 23 of different specifications can be springs of different lengths, so as to adjust the distance between the upper surface of the loading tray 21 and the lower focus of the ellipsoidal cavity according to actual needs.

In this embodiment, a material discharge channel 24 is also connected below the loading tray 21, and the material discharge channel 24 is connected to the opening at the bottom of the loading tray 21, and the length of the material discharge channel is ≤20cm. An opening switch 25 is provided at the opening. In this embodiment, the specific form of the opening switch is not limited, as long as it can block the opening and open the opening. Preferably, the opening switch is electrically connected to an external control device; or, the opening switch can also be a switch that is opened by bearing weight, for example, the opening switch is a valve-shaped switch, and the valve-shaped switch includes a number of springs arranged circumferentially around the inner wall of the opening, one end of the spring is connected to the inner wall of the opening, and the end of the spring away from the inner wall of the opening is a free end. In this embodiment, preferably, a vibration mechanism 26 is provided on the material discharge channel 24, and the specific form of the vibration mechanism is not limited, and a commercially available product can be used; preferably, the vibration mechanism is electrically connected to an external control device to control its vibration frequency. In this embodiment, preferably, a temperature sensor can be provided on the outer surface of the loading tray 21, and the temperature sensor is electrically connected to an external control device, so as to accurately obtain the opening time of the opening switch.

This embodiment also provides a quartz sand microwave purification method, as shown in FIG3, comprising the following steps:

S1. Crushing-screening treatment: crushing and screening the quartz ore to obtain quartz raw sand of preset size. In this embodiment, the quartz ore can be crushed by three processes: jaw, cone, and roller; the crushed quartz sand is screened to a suitable particle size, generally controlled within a preset size of 50 to 425 μm, and the matching screen specification corresponds to a mesh number ∈ [300, 40] mesh, preferably, the preset size ∈ [75, 250] μm, and the screen specification ∈ [200, 60] mesh.

S2. Initial purification treatment: The quartz raw sand is initially purified by purification methods including magnetic separation, flotation, and pickling. In this embodiment, the quartz raw sand of a preset size obtained after screening is subjected to magnetic separation using a strong magnetic separator to remove weakly magnetic impurity minerals, and then flotation is performed to remove non-magnetic associated impurity minerals. Finally, the quartz sand is pickled by a mixed acid of hydrochloric acid and nitric acid using the relatively stable chemical properties of quartz to further chemically treat and purify the surface of the quartz sand.

S3. Integrated purification treatment by microwave-water purification-pickling: Using the microwave purification device for quartz sand of the present embodiment, an acid solution is placed in a storage tank, a feeding mechanism is placed on a feeding mechanism positioning member of the lower shell, the upper shell and the lower shell are closed to seal the ellipsoidal cavity, and after vacuuming the ellipsoidal cavity through an air outlet pipe until the air pressure in the ellipsoidal cavity reaches a first preset air pressure, HCl gas is introduced into the ellipsoidal cavity through a feeding pipe until the air pressure in the ellipsoidal cavity reaches a second preset air pressure, the microwave generating mechanism is started, and HCl gas and the quartz sand obtained after the previous purification step are introduced into the ellipsoidal cavity through different feeding pipes respectively, the quartz sand falls into a loading tray and is heated by the microwave generating mechanism, and then falls into the acid solution in the storage tank through an opening for water purification and pickling.

In this embodiment, the acid solution in S3 is a mixed aqueous solution of hydrochloric acid and nitric acid, wherein the weight ratio of hydrochloric acid to nitric acid in the acid solution is 1:(1-1.5), the concentration of hydrochloric acid is 1.5-2.0 mol/L, the concentration of nitric acid is 1.5-2.0 mol/L, and the weight ratio of the quartz sand falling into the storage tank to the acid solution is 1:(3-8); and/or, when S3 is passed through the quartz sand obtained after the previous step of purification, the loading tray is vibrated by a vibration mechanism on a feeding channel connected to the bottom of the loading tray and connected to the opening at the bottom of the loading tray; and/or, the first preset air pressure is ≤1×10 ^-2 Pa, and the second preset air pressure is 13333-34666 Pa; and/or, the loading tray is a quartz loading tray, and the material is high-purity quartz glass or ceramic with a purity of ≥99.995%.

In this embodiment, when the microwave generating mechanism adopts a 2.45 GHz solid-state microwave source, the flow rate of HCl gas introduced into S3 is 0.1 to 1.5 L/min, the speed of introducing the quartz sand obtained after the previous step of purification is 0.5 to 2.5 kg/min, and the quartz sand is heated to 950 to 1200° C. by the microwave generating mechanism. When the microwave generating mechanism adopts a 915 MHz solid-state microwave source, the flow rate of HCl gas introduced into S3 is 0.35 to 6.5 L/min, the speed of introducing the quartz sand obtained after the previous step of purification is 1.5 to 10 kg/min, and the quartz sand is heated to 950 to 1200° C. by the microwave generating mechanism. Specifically, according to different microwave source specifications, the relationship between process parameters is shown in Table 1 below.

Table 1 Process parameters of step S3 under different microwave source specifications

S4, microwave-chlorination purification treatment: another quartz sand microwave purification device of the present embodiment is used, the feeding mechanism is placed on the feeding mechanism positioning piece of the lower shell, the upper shell and the lower shell are closed to make the ellipsoidal cavity in a sealed state, and after the air pressure in the ellipsoidal cavity reaches the third preset air pressure through the air outlet pipe, the gas in the ellipsoidal cavity is extracted from the air outlet pipe of the quartz sand microwave purification device used in S3, and the extracted gas is introduced into the ellipsoidal cavity through any feed pipe of the quartz sand microwave purification device used in S4, and _O2 and _Cl2 are introduced into the ellipsoidal cavity through other feed pipes until the air pressure in the ellipsoidal cavity reaches the fourth preset air pressure, the microwave generating mechanism is started, and the extracted gas, _O2 , _Cl2 and the quartz sand obtained after the previous purification are respectively introduced into the ellipsoidal cavity through different feed pipes, the quartz sand falls into the loading tray and is heated by the microwave generating mechanism and then falls into the storage tank through the opening, completing the microwave-chlorination purification treatment.

In this embodiment, the gas in the S3 ellipsoidal cavity can be extracted and stored in a gas storage device. When the pressure in the S3 ellipsoidal cavity is around normal pressure, the shell is opened to take out the quartz sand in the acid solution, dry it and use it as the purification object of S4. The gas extracted from the S3 ellipsoidal cavity is extracted from the gas storage device and passed into the quartz sand microwave purification device used in S4.

In this embodiment, when S4 is introduced into the quartz sand obtained after the previous step of purification, the loading tray is vibrated by a vibration mechanism on a feeding channel connected to the bottom of the loading tray and connected to an opening at the bottom of the loading tray; and/or, the third preset air pressure is ≤1×10 ^-2 Pa, and the fourth preset air pressure is 6666.5～23000Pa.

In this embodiment, when the microwave generating mechanism adopts a 2.45 GHz solid-state microwave source, the flow ratio of _O2 introduced into S4 and the gas introduced into the S3 ellipsoidal cavity is (0.1-2.4):100, the flow ratio of _Cl2 introduced into the S3 ellipsoidal cavity is (3-20):100, the speed of introducing the quartz sand obtained after the previous step of purification is 0.5-2.5 kg/min, and the quartz sand is heated to 800-1000°C by the microwave generating mechanism. When the microwave generating mechanism adopts a 915MHz solid-state microwave source, the flow ratio of _O2 introduced into S4 to the gas introduced into the S3 ellipsoidal cavity is (0.1-2.4):100, the flow ratio of _Cl2 introduced to the gas introduced into the S3 ellipsoidal cavity is (3-20):100, the speed of introducing the quartz sand obtained after the previous step of purification is 1.5-10kg/min, and the quartz sand is heated to 800-1000°C by the microwave generating mechanism. Specifically, according to different microwave source specifications, the relationship between process parameters is shown in Table 2 below.

Table 2 Process parameters of step S4 under different microwave source specifications

In this embodiment, preferably, steps S2-S4 can be cycled again or multiple times according to actual conditions until the purity of the quartz sand is qualified.

This embodiment also provides a high-purity quartz sand, which is purified according to the quartz sand microwave purification method of this embodiment.

Example 2

This embodiment provides a quartz sand microwave purification device, a quartz sand microwave purification method using the quartz sand microwave purification device, and high-purity quartz sand purified by using the quartz sand microwave purification method. This embodiment differs from Example 1 only in some process parameters of the quartz sand microwave purification method, and the similarities are not repeated here, and only the differences are described.

In the quartz sand microwave purification method of the present embodiment:

S1. Crushing-screening process: crushing and screening the quartz ore to obtain quartz raw sand with a preset size of 75 μm.

The weight ratio of hydrochloric acid to nitric acid in the acid solution in S3 is 1:1, the concentration of hydrochloric acid is 1.5 mol/L, the concentration of nitric acid is 1.5 mol/L, and the weight ratio of quartz sand falling into the storage tank to the acid solution is 1:3; the first preset air pressure is ≤1×10 ^-2 Pa, and the second preset air pressure is 13333 Pa. The microwave generating mechanism adopts a 2.45 GHz solid-state microwave source, the flow rate of HCl gas introduced into S3 is 0.1 L/min, the speed of introducing the quartz sand obtained after the previous step of purification is 0.5 kg/min, and the quartz sand is heated to 950°C by the microwave generating mechanism. Specifically, the relationship between the process parameters is shown in Table 3 below.

Table 3 Process parameters of step S3

Microwave source specifications 2.45GHz Microwave output power 4kw HCl gas flow rate 0.1L/min Quartz feeding amount 0.5kg/min Controlling the temperature of quartz sand microwave heating 950℃ Distance between the quartz carrier plate ellipsoid and the lower focus 30mm Quartz carrier plate vibration frequency 1Hz

The third preset gas pressure in S4 is ≤1×10 ^-2 Pa, and the fourth preset gas pressure is 6666.5 Pa. The microwave generating mechanism adopts a 2.45GHz solid-state microwave source, the flow ratio of O ₂ introduced into S4 to the gas introduced into the S3 ellipsoidal cavity is 0.1:100, the flow ratio of Cl ₂ introduced to the gas introduced into the S3 ellipsoidal cavity is 3:100, the speed of introducing the quartz sand obtained after the previous step of purification is 0.5kg/min, and the quartz sand is heated to 800°C by the microwave generating mechanism. Specifically, the relationship between the process parameters is shown in Table 4 below.

Table 4 S4 step process parameters

In this embodiment, the number of cycles of steps S2-S4 is 2 times.

Example 3

This embodiment provides a quartz sand microwave purification device, a quartz sand microwave purification method using the quartz sand microwave purification device, and high-purity quartz sand purified by using the quartz sand microwave purification method. This embodiment differs from Example 2 only in some process parameters of the quartz sand microwave purification method, and the similarities are not repeated here, and only the differences are described.

In the quartz sand microwave purification method of the present embodiment:

The microwave generating mechanism in S3 uses a solid-state microwave source of 915 MHz, the flow rate of HCl gas introduced into S3 is 0.35 L/min, and the speed of introducing the quartz sand obtained after the previous step of purification is 1.5 kg/min. Specifically, the relationship between the process parameters is shown in Table 5 below.

Table 5 S3 step process parameters

The microwave generating mechanism in S4 uses a solid-state microwave source of 915 MHz, and the speed of introducing the quartz sand obtained after the previous step of purification into S4 is 1.5 kg/min. Specifically, the relationship between the process parameters is shown in Table 6 below.

Table 6 Process parameters of step S4

Microwave source specifications 915MHz Microwave output power 12kw Quartz feeding amount 1.5kg/min Distance between the quartz carrier plate ellipsoid and the lower focus 75mm Quartz carrier plate vibration frequency 0.1Hz

Example 4

This embodiment provides a quartz sand microwave purification device, a quartz sand microwave purification method using the quartz sand microwave purification device, and high-purity quartz sand purified by using the quartz sand microwave purification method. This embodiment differs from Example 1 only in some process parameters of the quartz sand microwave purification method, and the similarities are not repeated here, and only the differences are described.

In the quartz sand microwave purification method of the present embodiment:

S1. Crushing-screening process: crushing and screening the quartz ore to obtain quartz raw sand with a preset size of 150 μm.

The weight ratio of hydrochloric acid to nitric acid in the acid solution in S3 is 1:1.25, the concentration of hydrochloric acid is 1.7 mol/L, the concentration of nitric acid is 1.7 mol/L, and the weight ratio of quartz sand falling into the storage tank to the acid solution is 1:5; the first preset air pressure is ≤1×10 ^{- 2} Pa, and the second preset air pressure is 20000 Pa. The microwave generating mechanism adopts a 2.45GHz solid-state microwave source, the flow rate of HCl gas introduced into S3 is 1.0L/min, the speed of introducing the quartz sand obtained after the previous step of purification is 1.5kg/min, and the quartz sand is heated to 1000°C by the microwave generating mechanism. Specifically, the relationship between the process parameters is shown in Table 7 below.

Table 7 Process parameters of step S3

The third preset gas pressure in S4 is ≤1×10 ^-2 Pa, and the fourth preset gas pressure is 10000 Pa. The microwave generating mechanism adopts a 2.45GHz solid-state microwave source, the flow ratio of O ₂ introduced into S4 to the gas introduced into the S3 ellipsoidal cavity is 1:100, the flow ratio of Cl ₂ introduced to the gas introduced into the S3 ellipsoidal cavity is 10:100, the speed of introducing the quartz sand obtained after the previous step of purification is 1.5kg/min, and the quartz sand is heated to 900°C by the microwave generating mechanism. Specifically, the relationship between the process parameters is shown in Table 8 below.

Table 8 S4 step process parameters

In this embodiment, the number of cycles of steps S2-S4 is 3 times.

Example 5

This embodiment provides a quartz sand microwave purification device, a quartz sand microwave purification method using the quartz sand microwave purification device, and high-purity quartz sand purified by using the quartz sand microwave purification method. This embodiment differs from Example 4 only in some process parameters of the quartz sand microwave purification method, and the similarities are not repeated here, and only the differences are described.

In the quartz sand microwave purification method of the present embodiment:

The microwave generating mechanism in S3 uses a solid-state microwave source of 915 MHz, the flow rate of HCl gas introduced into S3 is 3.5 L/min, and the speed of introducing the quartz sand obtained after the previous step of purification is 5 kg/min. Specifically, the relationship between the process parameters is shown in Table 9 below.

Table 9S3 step process parameters

The microwave generating mechanism in S4 uses a solid-state microwave source of 915 MHz, and the speed of introducing the quartz sand obtained after the previous step of purification into S4 is 5 kg/min. Specifically, the relationship between the process parameters is shown in Table 10 below.

Table 10 Process parameters of step S4

Microwave source specifications 915MHz Microwave output power 35kw Quartz feeding amount 5kg/min Distance between the quartz carrier plate ellipsoid and the lower focus 90mm Quartz carrier plate vibration frequency 8Hz

Example 6

This embodiment provides a quartz sand microwave purification device, a quartz sand microwave purification method using the quartz sand microwave purification device, and high-purity quartz sand purified by using the quartz sand microwave purification method. This embodiment differs from Example 1 only in some process parameters of the quartz sand microwave purification method, and the similarities are not repeated here, and only the differences are described.

In the quartz sand microwave purification method of the present embodiment:

S1. Crushing-screening process: crushing and screening the quartz ore to obtain quartz raw sand with a preset size of 250 μm.

The weight ratio of hydrochloric acid to nitric acid in the acid solution in S3 is 1:1.5, the concentration of hydrochloric acid is 2.0 mol/L, the concentration of nitric acid is 2.0 mol/L, and the weight ratio of quartz sand falling into the storage tank to the acid solution is 1:8; the first preset air pressure is ≤1×10 ^-2 Pa, and the second preset air pressure is 34666 Pa. The microwave generating mechanism adopts a 2.45 GHz solid-state microwave source, the flow rate of HCl gas introduced into S3 is 1.5 L/min, the speed of introducing the quartz sand obtained after the previous step of purification is 2.5 kg/min, and the quartz sand is heated to 1200°C by the microwave generating mechanism. Specifically, the relationship between the process parameters is shown in Table 11 below.

Table 11 Process parameters of step S3

The third preset gas pressure in S4 is ≤1×10 ^-2 Pa, and the fourth preset gas pressure is 23000 Pa. The microwave generating mechanism adopts a 2.45GHz solid-state microwave source, the flow ratio of O ₂ introduced into S4 to the gas introduced into the S3 ellipsoidal cavity is 2.4:100, the flow ratio of Cl ₂ introduced to the gas introduced into the S3 ellipsoidal cavity is 20:100, the speed of introducing the quartz sand obtained after the previous step of purification is 2.5kg/min, and the quartz sand is heated to 1000°C by the microwave generating mechanism. Specifically, the relationship between the process parameters is shown in Table 12 below.

Table 12S4 step process parameters

In this embodiment, the number of cycles of steps S2-S4 is 3 times.

In this embodiment, impurity detection is performed on the high-purity quartz sand obtained by the quartz sand microwave purification method of this embodiment. The detection results are shown in Table 13 below.

Table 13 Comparison of impurity content of original quartz ore and high-purity quartz sand purified in this example

As shown in Table 13, compared with the original quartz ore that has not been purified, the high-purity quartz sand obtained after purification in this embodiment has extremely low impurity content, and some of the original impurities are not detected after purification, which further illustrates that the purification effect is good when the purification device of this embodiment is used for purification. FIG4 shows a comparison diagram of quartz sand purified by the quartz sand microwave purification method of this embodiment and bubbling after heating the unpurified quartz sand. As shown in FIG4, the original quartz ore (unpurified quartz sand) contains a large amount of impurities, and the quartz sand purified by the quartz sand microwave purification method of this embodiment has extremely low impurity content. The purification effect is good when the purification device of this embodiment is used for purification.

Example 7

This embodiment provides a quartz sand microwave purification device, a quartz sand microwave purification method using the quartz sand microwave purification device, and high-purity quartz sand purified by using the quartz sand microwave purification method. This embodiment differs from Example 6 only in some process parameters of the quartz sand microwave purification method, and the similarities are not repeated here, and only the differences are described.

In the quartz sand microwave purification method of the present embodiment:

The microwave generating mechanism in S3 uses a solid-state microwave source of 915 MHz, the flow rate of HCl gas introduced into S3 is 6.5 L/min, and the speed of introducing the quartz sand obtained after the previous step of purification is 10 kg/min. Specifically, the relationship between the process parameters is shown in Table 14 below.

Table 14 Process parameters of step S3

The microwave generating mechanism in S4 uses a solid-state microwave source of 915 MHz, and the speed of introducing the quartz sand obtained after the previous step of purification into S4 is 10 kg/min. Specifically, the relationship between the process parameters is shown in Table 15 below.

Table 15 Process parameters of step S4

Microwave source specifications 915MHz Microwave output power 70kw Quartz feeding amount 10kg/min Distance between the quartz carrier plate ellipsoid and the lower focus 125mm Quartz carrier plate vibration frequency 15Hz

The present invention has been described above in conjunction with specific embodiments. These specific embodiments are merely exemplary and cannot be used to limit the scope of protection of the present invention. Those skilled in the art may make various modifications, changes or substitutions without departing from the essence of the present invention. Therefore, various equivalent changes made according to the present invention still fall within the scope covered by the present invention.

Claims (10)

1. A quartz sand microwave purifying device is characterized by comprising a microwave generating mechanism, a material placing mechanism and a shell,

the inner wall of the shell encloses an ellipsoidal cavity, the shell comprises an upper shell and a lower shell, the upper shell and the lower shell are detachably connected, the upper shell is provided with an air outlet pipe extending into the ellipsoidal cavity and a plurality of feeding pipes extending into the ellipsoidal cavity, and a positioning part of a material placing mechanism is arranged at the position of the lower shell corresponding to a long half shaft of the ellipsoidal cavity;

the microwave generating mechanism stretches into the ellipsoidal cavity from the position of the upper shell corresponding to the long half shaft of the ellipsoidal cavity, and the microwave generating position of the microwave generating mechanism is positioned at the upper focus of the ellipsoidal cavity;

the material placing mechanism comprises a material carrying disc and a storage groove positioned below the material carrying disc, the material carrying disc is connected with the storage groove, and an opening is formed in the bottom of the material carrying disc.

2. The quartz sand microwave purifying device according to claim 1, wherein the opening ends of the upper shell and the lower shell are respectively provided with a flange, and the upper shell and the lower shell are connected by a bolt and nut structure through mounting holes on the flanges; and/or one end of the feeding pipe extending into the ellipsoidal cavity faces to the lower focus of the ellipsoidal cavity; and/or the positioning piece of the material placing mechanism is in a groove shape, the shape of the positioning piece of the material placing mechanism is matched with the outer surface of the storage groove, and the storage groove can be embedded into the positioning piece of the material placing mechanism.

3. The quartz sand microwave purification apparatus of claim 1, wherein the microwave generation mechanism employs a 2.45GHz solid state microwave source or a 915MHz solid state microwave source;

when the material placing mechanism is placed on the material placing mechanism positioning piece by means of the storage groove, the material placing mechanism is positioned on the long half shaft of the ellipsoidal cavity; when the microwave generating mechanism adopts a 2.45GHz solid microwave source, the distance between the upper surface of the material carrying disc and the lower focus of the ellipsoidal cavity is 30-45 mm, and the diameter of the upper end surface of the material carrying disc is less than or equal to 5cm and less than or equal to 10cm; when the microwave generating mechanism adopts a 915MHz solid-state microwave source, the distance between the upper surface of the material carrying tray and the lower focus of the ellipsoidal cavity is 75-125 mm, and the diameter of the upper end surface of the material carrying tray is less than or equal to 5cm and less than or equal to 15cm.

4. The quartz sand microwave purifying device according to claim 1, wherein the loading tray is detachably connected with the storage tank, the outer surface of the loading tray is provided with loading tray connecting seats at intervals, the upper part of the storage tank is provided with storage tank connecting seats at intervals, mounting through holes are formed in the loading tray connecting seats and the storage tank connecting seats, and the loading tray and the storage tank can be connected through elastic pieces with different specifications by means of the mounting through holes.

5. The quartz sand microwave purification device according to claim 1, wherein a blanking channel is further connected below the loading tray, the blanking channel is communicated with an opening at the bottom of the loading tray, and the length of the blanking channel is less than or equal to 20cm;

The opening is provided with an opening switch, and the blanking channel is provided with a vibrating mechanism.

6. The quartz sand microwave purification method is characterized by comprising the following steps of:

s1, crushing-screening treatment: crushing and screening quartz ores to obtain quartz raw sand with preset size;

s2, initial purification treatment: the quartz raw sand is initially purified in a purification mode comprising magnetic separation, flotation and acid washing;

s3, microwave-water extraction-acid washing integrated purification treatment: applying the quartz sand microwave purification device according to any one of claims 1-5, placing an acid solution in a storage tank, placing a material placing mechanism on a material placing mechanism positioning piece of a lower shell, sealing the upper shell and the lower shell to enable an ellipsoidal cavity to be in a sealed state, vacuumizing through an air outlet pipe until the air pressure in the ellipsoidal cavity reaches a first preset air pressure, introducing HCl gas into the ellipsoidal cavity through a feed pipe until the air pressure in the ellipsoidal cavity reaches a second preset air pressure, starting a microwave generating mechanism, introducing HCl gas into the ellipsoidal cavity through different feed pipes and obtaining quartz sand after the previous purification, wherein the quartz sand falls into a material carrying disc and is heated by the microwave generating mechanism and then falls into the acid solution in the storage tank through an opening for water extraction and acid washing;

S4, microwave-chlorination purification treatment: use of the other claim1-5, placing a material placing mechanism on a material placing mechanism positioning piece of a lower shell, sealing the upper shell and the lower shell to enable an ellipsoidal cavity to be in a sealing state, vacuumizing through an air outlet pipe until the air pressure in the ellipsoidal cavity reaches a third preset air pressure, extracting air in the ellipsoidal cavity from the air outlet pipe of the quartz sand microwave purifying device applied by S3, introducing the extracted air into the ellipsoidal cavity through any one of the feed pipes of the quartz sand microwave purifying device applied by S4, and introducing O into the ellipsoidal cavity through other feed pipes ₂ And Cl ₂ Starting the microwave generating mechanism until the air pressure in the ellipsoidal cavity reaches a fourth preset air pressure, and respectively introducing the extracted air and O into the ellipsoidal cavity through different feeding pipes ₂ 、Cl ₂ And quartz sand obtained after the purification in the last step falls into a material carrying disc, is heated by a microwave generating mechanism and falls into a storage tank through an opening, and thus the microwave-chlorination purification treatment is completed.

7. The quartz sand microwave purification method of claim 6, wherein the preset size is 50-425 μm; and/or the acid solution in the S3 is a mixed aqueous solution of hydrochloric acid and nitric acid, wherein the weight ratio of the hydrochloric acid to the nitric acid in the acid solution is 1 (1-1.5), the concentration of the hydrochloric acid is 1.5-2.0 mol/L, the concentration of the nitric acid is 1.5-2.0 mol/L, and the weight ratio of quartz sand falling into the storage tank to the acid solution is 1 (3-8); and/or, when S3-S4 is introduced into the quartz sand obtained after the purification in the previous step, vibrating the material carrying disc through a vibrating mechanism on a discharging channel connected below the material carrying disc and communicated with an opening at the bottom of the material carrying disc; and/or, the first preset air pressure and the third preset air pressure are both less than or equal to 1 multiplied by 10 ^-2 Pa, the second preset air pressure is 13333-34666 Pa, and the fourth preset air pressure is 6666.5-23000 Pa.

8. The method for purifying quartz sand by microwave as claimed in claim 6, wherein when the microwave generating mechanism adopts a 2.45GHz solid microwave source, the flow rate of HCl gas introduced in S3 is 0.1-1.5L/min, and the velocity of quartz sand obtained after the previous purification is 0.5 d2.5kg/min, heating quartz sand to 950-1200 ℃ by a microwave generating mechanism; o introduced in S4 ₂ The flow ratio of the gas to the gas in the S3 ellipsoidal cavity is (0.1-2.4): 100, and the Cl is introduced ₂ The flow ratio of the quartz sand to the gas in the introduced S3 ellipsoidal cavity is (3-20): 100, the speed of the quartz sand obtained after the purification in the last step is 0.5-2.5 kg/min, and the quartz sand is heated to 800-1000 ℃ by a microwave generating mechanism.

9. The quartz sand microwave purification method as claimed in claim 6, wherein when the microwave generating mechanism adopts a 915MHz solid microwave source, the flow rate of HCl gas introduced in S3 is 0.35-6.5L/min, the velocity of quartz sand obtained after the previous purification is 1.5-10 kg/min, and the quartz sand is heated to 950-1200 ℃ by the microwave generating mechanism; o introduced in S4 ₂ The flow ratio of the gas to the gas in the S3 ellipsoidal cavity is (0.1-2.4): 100, and the Cl is introduced ₂ The flow ratio of the quartz sand to the gas in the introduced S3 ellipsoidal cavity is (3-20): 100, the speed of the quartz sand obtained after the purification in the last step is 1.5-10 kg/min, and the quartz sand is heated to 800-1000 ℃ by a microwave generating mechanism.

10. A high purity silica sand, characterized in that it is purified by the silica sand microwave purification method according to any one of claims 6 to 9.