Deep purification equipment and method for high-purity quartz sand

Abstract

The invention provides deep purification equipment and method for high-purity quartz sand, the deep purification equipment comprises a vertical reactor shell, a gas uniform distribution chamber, an electric heating section, a reaction section and an expansion section are sequentially arranged in the reactor shell from bottom to top, a gas inlet is formed in the gas uniform distribution chamber, and a gas outlet is formed in the gas uniform distribution chamber; a high-purity quartz sand feeding hole and a gas outlet are formed in the reactor shell and positioned at the top of the expansion section, a cooling device is arranged inside / outside the expansion section, and a finished product discharging hole is formed in the bottom of the reaction section. According to the equipment disclosed by the invention, after entering the uniform distribution chamber, gas upwards enters the electric heating section, so that chlorine gas can be well ensured to be uniformly distributed and heated in the heating section. After being heated to 1000-1200 DEG C in the heating section, gas passes through the reaction section, and gas flow passes through the high-purity quartz sand layer to be fluidized to generate a fluidized bed, so that the specific surface area of gas-solid reaction is greatly increased, and the reaction rate is improved, thereby ensuring that a product can be continuously and stably extracted from the discharging pipeline.

Description

Technical Field

[0001] The present invention relates to the fields of high-purity quartz sand processing and purification, and specifically, to a deep purification device and method for high-purity quartz sand. Background Art

[0002] High-purity quartz sand generally refers to quartz and its products with a SiO2 content greater than 99.9% and extremely low impurity element content, and is the material basis for high-end products in the silicon industry. The unique molecular structure, crystal shape, and lattice characteristics of high-purity quartz endow it with characteristics such as low thermal conductivity, good thermal shock resistance, high deformation and softening temperatures, low dielectric loss, and high light transmittance, and it has a very wide range of application fields. With the rapid development of strategic emerging industries, high-purity quartz has become one of the basic raw materials in many cutting-edge fields such as the electronic information industry, intelligent manufacturing equipment industry, photovoltaic and semiconductor industries. The demand in the photovoltaic and semiconductor fields has grown rapidly in recent years, but the production capacity of high-end products with a purity grade above 4N5 (SiO2 = �9.995%) is small, and it is mainly used to manufacture quartz crucibles, quartz tubes, quartz rods, quartz boats, and quartz ingots. Among them, the inner layer of the quartz crucible has higher requirements for the purity of high-purity quartz sand, and the purity grade needs to reach 4N8 (SiO2 = �9.998%) and above.

[0003] The main impurity elements in high-purity quartz sand are Al, Fe, Ga, Mg, Li, Na, K, Ti, B, Ni, etc., and the occurrence states of impurities can be divided into three categories: gangue mineral impurities, gas-liquid inclusion impurities, and isomorphic impurities. Among them, impurities existing in the isomorphic state, such as impurity elements such as Al, Fe, Ti, Li, and B, are difficult to remove. Impurity elements have a great impact on the quality of high-purity quartz products, and the content of the above metal elements is a key index for high-purity quartz raw materials.

[0004] The existing high-purity quartz sand purification process mainly goes through steps such as hand selection, calcination and water quenching, crushing and classification, weak magnetic separation, flotation, pickling, cleaning, drying, strong magnetic separation, etc., and finally produces high-purity quartz sand products with a metal impurity content less than 50 ppm. To further improve the product quality and stabilize the total amount of metal ion impurities below 20 ppm, the above high-purity quartz sand needs to be further deeply purified, so a new technical solution needs to be provided to solve this problem. Summary of the Invention

[0005] The purpose of the present invention is to provide a deep purification device and method for high-purity quartz sand that removes metal impurities in high-purity quartz sand to improve its purity.

[0006] The present invention is implemented as follows:

[0007] The present invention provides a deep purification device for high-purity quartz sand, which is characterized in that it includes a vertical reactor shell. Inside the reactor shell, there are successively arranged a gas distribution chamber, an electric heating section, a reaction section, and an enlarged section from bottom to top. An air inlet is provided at the gas distribution chamber. On the reactor shell, a high-purity quartz sand feed inlet and an air outlet are arranged at the top of the enlarged section. A cooling device is arranged inside and / or outside the enlarged section, and a finished product discharge port is arranged at the bottom of the reaction section.

[0008] In some alternative embodiments, the heating section is heated by electrode energization and filled with spherical carbon particles.

[0009] In some alternative embodiments, a gas distribution plate is arranged between the electric heating section and the reaction section. A plurality of air holes are evenly arranged on the gas distribution plate, and each air hole is equipped with a wind cap.

[0010] In some alternative embodiments, thermometers are respectively arranged at the gas distribution chamber, the reaction section, and the enlarged section.

[0011] In some alternative embodiments, a weighing and metering tank is arranged at the top of the reactor shell. The metering tank pads solid materials into the reaction section through the feed inlet in a spiral feeding form.

[0012] In some alternative embodiments, the reactor shell successively includes a heat insulation layer, a high-temperature resistant layer, and a steel plate layer from inside to outside.

[0013] A method for deeply purifying high-purity quartz sand by using the above-mentioned deep purification device for high-purity quartz sand is characterized in that it includes the following steps:

[0014] Step 1: Pre-dry the raw material quartz sand at 100 - 150 °C until its dew point < 40 °C is detected, and then detect the bulk density of the dried material, and control its bulk density to be 1.5 - 1.85 g / cm 2 ;

[0015] Step 2: Pad 500 ± 50 mm thick solid materials into the reaction section through the reactor feed inlet;

[0016] Step 3: Start the electric heater to raise the temperature of the carbon particles in the heating section to 1000 - 1200 °C for standby;

[0017] Step 4: Then introduce chlorine gas with a purity of 99.9% through the air inlet at the bottom of the reactor. After the chlorine gas is evenly distributed through the gas distribution chamber, it enters the heating section;

[0018] Step 5: The chlorine gas is heated to 1000 - 1200 °C in the heating section and then enters the reaction section;

[0019] Step 6: When chlorine gas passes through the reaction section, the solid material is blown up to form a fluidized state. After the chlorine gas reacts with the impurities in the material, it rises with the gas flow. After being depressurized through the expansion section and cooled by the jacket water to 300 - 500 °C, it enters the post-treatment system from the gas outlet.

[0020] Step 7: After reacting for a period of time, the purified high-purity quartz sand product in the reaction section starts to be discharged through the discharge port into the product metering tank. At the same time, the top feed port starts to feed through the raw material metering tank to ensure the stable material level in the material layer (i.e., w 进料 ≈w 出料 ), to avoid damaging the fluidized state.

[0021] In some alternative embodiments, the chlorine gas flow rate is controlled as: u mf <u0<u t， where u0 is the chlorine gas flow rate, u mf is the initial fluidization velocity, and u t is the escape velocity of the quartz sand particles;

[0022] The chlorine gas flow rate is controlled as: u mf <u0<u t， where u0 is the chlorine gas flow rate, u mf is the initial fluidization velocity, and u t is the escape velocity of the quartz sand particles;

[0023] When the resistance when the gas flows through the solid bed layer of the reactor is equal to the weight of the quartz sand particles, the particles in the bed layer start to flow. At this time, the gas flow rate is the initial fluidization velocity u mf , for the quartz sand particles where d p is the average particle size of the quartz sand particles, ρ p is the density of the quartz sand particles, ρ is the density of chlorine gas, μ is the viscosity of chlorine gas, and g is the acceleration due to gravity; when the gas flow rate > u mf , the bed layer particles reach the fluidized state. If the gas flow rate is too large, the quartz sand particles will be carried out of the reactor. Therefore, it is also necessary to satisfy that the gas flow rate is less than the escape velocity of the quartz sand particles That is: the chlorine gas flow rate is controlled as: u mf <u0<u t .

[0024] In some alternative embodiments, the chlorine gas flow rate is 0.01 - 0.05 m / s.

[0025] In some alternative embodiments, in Step 7: Keep the inlet and outlet rates of the reactor at 6.5 - 7.5 kg / min, and control the pressure difference between the upper and lower ends of the reaction chamber at 5 - 8 kPa.

[0026] The melting point of the high-purity quartz sand provided by the present invention is 1750 °C. Under certain temperature and atmosphere conditions, when chlorine gas is introduced, the impurity component ions can be converted into low-boiling chlorides while the high-purity quartz sand will not be reacted, thereby separating the impurity components.

[0027] The beneficial effects of the present invention are as follows:

[0028] 1. Through the equipment of the present invention, after the gas enters the distribution chamber, it enters the electric heating section upward, which can well ensure the uniform distribution and heating of chlorine gas in the heating section. After the gas is heated to 1000 - 1200 °C in the heating section, it passes through the reaction section. The gas flow passes through the high-purity quartz sand material layer to make it in a fluidized state, generating a fluidized bed, greatly increasing the gas-solid reaction specific surface area, improving the reaction rate, thus ensuring that the product can be continuously and stably withdrawn from the discharge pipeline, and greatly improving the production efficiency.

[0029] 2. The heating section uses electrode-powered heating and is filled with spherical carbon particles. When powered on, the spherical carbon particles generate heat to heat the gas, effectively improving the thermal energy utilization rate and achieving the purpose of energy saving.

[0030] 3. Entering the electric heating section upward through the gas distributor can well ensure the uniform distribution and heating of chlorine gas in the heating section. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following will briefly introduce the drawings required to be used in the embodiments. It should be understood that the following drawings only show some embodiments of the present invention, and therefore should not be regarded as limiting the scope. For those of ordinary skill in the art, without creative efforts, other related drawings can also be obtained based on these drawings.

[0032] Figure 1 The front view of a deep purification device for high-purity quartz sand provided by an embodiment of the present invention;

[0033] Figure 2 The top view of the gas distribution plate provided by an embodiment of the present invention.

[0034] Figure 3 The main sectional view of the gas distribution plate provided by an embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0036] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. Usually, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0037] Accordingly, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely represents selected embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present invention without creative efforts shall fall within the scope of protection of the present invention.

[0038] It should be noted that like reference numerals and letters denote like items in the following drawings. Therefore, once an item is defined in one drawing, it does not require further definition and explanation in subsequent drawings.

[0039] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship in which the product of this application is customarily placed during use. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation of the present invention. In addition, the terms "first", "second", "third", etc. are only used for descriptive distinction and should not be construed as indicating or implying relative importance.

[0040] In addition, the terms "horizontal", "vertical", "hanging", etc. do not mean that the components are required to be absolutely horizontal or hanging, but may be slightly inclined. For example, "horizontal" only means that its direction is more horizontal relative to "vertical", and does not mean that the structure must be completely horizontal, but may be slightly inclined.

[0041] In the description of the present invention, it should also be noted that unless otherwise clearly specified and defined, the terms "set", "installed", "connected", "connected" should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0042] In the present invention, unless otherwise clearly specified and defined, the first feature being "above" or "below" the second feature may include the direct contact between the first and second features, or may include the situation where the first and second features are not in direct contact but in contact through additional features therebetween. Moreover, the first feature being "above", "over" and "on top of" the second feature includes that the first feature is directly above and obliquely above the second feature, or merely indicates that the horizontal height of the first feature is higher than that of the second feature. The first feature being "below", "beneath" and "underneath" the second feature includes that the first feature is directly below and obliquely below the second feature, or merely indicates that the horizontal height of the first feature is lower than that of the second feature.

[0043] The features and performance of the present invention will be further described in detail below in conjunction with embodiments.

[0044] Embodiment 1:

[0045] This embodiment provides a deep purification device for high-purity quartz sand, which includes a vertical reactor shell 1. Inside the reactor shell 1, a gas distribution chamber 121, an electric heating section 122, a reaction section 123 and an expansion section 124 are successively arranged from bottom to top. An air inlet 11 is provided at the gas distribution chamber 121, an electrode 2 is provided in the electric heating section 122, a finished product discharge port (12, 13) is arranged at the bottom of the reaction section, a cooling device 3 is arranged inside and / or outside the expansion section, a high-purity quartz sand feed port 14, an air outlet 15 and a manhole 4 are arranged at the top of the expansion section on the reactor shell 1, and thermometers (11, 112, 113) are respectively arranged at the gas distribution chamber, the reaction section and the expansion section.

[0046] In this embodiment, a gas distribution plate (16, 17) is arranged between the electric heating section and the reaction section. As Figure 2 shown, a plurality of air holes 131 are uniformly arranged on the plate body 130 of the gas distribution plate, and each air hole is configured with a wind cap 132. The wind cap is designed in an umbrella shape, that is, the top of the wind cap is in a closed state, and there are 4 air holes with a diameter of 6 mm symmetrically arranged around it. In this way, while ensuring the ventilation volume, the blockage of the air holes can be effectively organized.

[0047] In this embodiment, the reactor shell is made of a high-temperature resistant material, which successively includes a heat insulation layer, a high-temperature resistant layer and a steel plate layer from the inside to the outside.

[0048] In this embodiment, a weighing and metering tank is arranged at the top of the reactor shell, and the metering tank feeds solid materials into the reaction section through the feed port in a spiral feeding form.

[0049] During production operation, a certain amount of high-purity quartz sand is added to the reaction section through the top feeding pipe. Chlorine gas enters the gas distribution chamber 121 from the air inlet, then passes through the electric heating section 122 and is heated to 1000 - 1200 °C. The high-temperature chlorine gas enters the reaction section 123, reacts with the impurities existing in the solid raw materials, and then is cooled to 300 - 500 °C through the expansion section 124. It is discharged from the air outlet 15 and enters the subsequent process. The finished high-purity quartz sand after the reaction is continuously discharged from the reaction section discharge port.

[0050] In the above reactor, after the gas enters the distribution chamber, it enters the electric heating section 122 upward through the gas distributor 121, which can well ensure the uniform distribution and heating of chlorine gas in the heating section. The heating section is heated by the electrode 2 and filled with spherical carbon particles. Under the energized condition, the spherical carbon particles generate heat to heat the gas, effectively improving the thermal energy utilization rate and achieving the purpose of energy saving. After the gas is heated to 1000 - 1200 °C in the heating section, it passes through the reaction section. The gas flow passes through the high-purity quartz sand layer to make it in a fluidized state, generating a fluidized bed. That is, in the fluidized state, the solid powder is blown up into a discrete state. In this state, the contact area between the solid powder and chlorine gas is greatly increased, the gas-solid reaction specific surface area is greatly increased, and the reaction rate is improved, thus ensuring that the product can be continuously and stably taken out from the discharge pipeline.

[0051] The heating section 122 of this embodiment is located between the upper and lower gas distribution trays, with an overall height of 1800 mm. There are two layers of graphite electrodes (connected to the power supply to provide heat source) arranged up and down, and the number of electrodes in each layer is 6, evenly distributed. The remaining space is filled with spherical carbon particles. Under the energized condition, the heat generated by the electrodes is conducted to the carbon particles. The carbon particles in the heating section are calcined petroleum coke, and the calcination temperature is generally about 1300 °C, which has the characteristics of high density, high purity, high strength, low ablation amount, low thermal expansion coefficient, and good thermal conductivity. The carbon particle diameter is preferably 2 - 5 mm. Such calcined petroleum coke filled in the heating section can effectively conduct the thermal energy generated by the graphite electrodes, improve the thermal energy utilization rate, and its particle gaps are conducive to the passage of gas and achieve the purpose of uniform gas distribution. Because of its large porosity, there will be no too much resistance when the gas passes through. In this way, the temperature of the gas can be raised to 1000 - 1200 °C when passing through the 1800 mm carbon particle layer.

[0052] This embodiment also provides a method for deep purification of high-purity quartz sand using the above-mentioned deep purification equipment for high-purity quartz sand, including the following steps:

[0053] Step 1: Pre-dry the raw material quartz sand at 100 °C until its dew point < 40 °C is detected, and then detect the bulk density of the dried material, and control its bulk density to be 1.5 g / cm 2 ;

[0054] Step 2: Pad 500 mm thick solid materials into the reaction section through the reactor feed port;

[0055] Step 3: Start the electric heater to raise the temperature of the carbon particles in the heating section to 1100 °C for standby;

[0056] Step 4: Then introduce chlorine gas with a purity of 99.9% through the air inlet at the bottom of the reactor. After being evenly distributed by the gas distribution chamber, the chlorine gas enters the heating section;

[0057] Step 5: The chlorine gas is heated to 1100 °C in the heating section and then enters the reaction section;

[0058] Step 6: When the chlorine gas passes through the reaction section, the solid materials are blown up to form a fluidized state. After the chlorine gas reacts with the impurities in the materials, it rises with the gas flow. After being depressurized by the expansion section and cooled by the jacket water to 300 °C (Ideal gas state equation PV = nRT, the temperature decreases when the volume expands), it enters the post-treatment system from the gas outlet;

[0059] Step 7: After reacting for a period of time, the purified high-purity quartz sand product in the reaction section starts to be discharged through the discharge port into the product metering tank. At the same time, the top feed port starts to feed through the raw material metering tank, keeping the inlet and outlet rates of the reactor at 6.5 kg / min and keeping the pressure difference between the upper and lower ends of the reaction chamber controlled at 5 kPa, so as to ensure the stability of the material layer level (i.e., w 进料 ≈w 出料 ), and avoid the destruction of the fluidized state.

[0060] Control the chlorine gas flow rate as: u mf <u0<u t， where u0 is the chlorine gas flow rate, u mf is the initial fluidization velocity, and u t is the escape velocity of the quartz sand particles;

[0061] When the resistance when the gas flows through the solid bed layer of the reactor is equal to the weight of the quartz sand particles, the particles in the bed layer start to flow, and the gas flow rate at this time is the initial fluidization velocity u mf For the quartz sand particles where d p is the average particle size of the quartz sand particles, ρ p is the density of the quartz sand particles, ρ is the density of the chlorine gas, μ is the viscosity of the chlorine gas, and g is the acceleration of gravity; when the gas flow rate > u mf , the bed layer particles reach the fluidized state. If the gas flow rate is too large, the quartz sand particles will be carried out of the reactor. Therefore, it is also necessary to ensure that the gas flow rate is less than the escape velocity of the quartz sand particles That is: Control the chlorine gas flow rate as: u mf <u0<u t .

[0062] Combined with various particle sizes of quartz sand in the market, the gas flow rate is selected to be 0.01 - 0.05 m / s, and preferably the space velocity of 0.015 - 0.03 m / s is added to the reactor.

[0063] The metal impurity content of the high-purity quartz sand product processed from the above examples can be effectively controlled within 20 ppm (specific experimental data refer to Table 1), meeting the requirements of the photovoltaic and semiconductor fields.

[0064] Table 1: Comparison of element content in Sample 1 before and after processing

[0065]

[0066] Example 2:

[0067] The structure of the deep purification equipment in this example is basically the same as that in Example 1, except for the purification method; specifically: the purification method includes the following steps:

[0068] Step 1: Pre-dry the raw material quartz sand at 150 °C until its dew point < 40 °C is detected, and then detect the bulk density of the dried material, and control its bulk density to be 1.85 g / cm 2 ;

[0069] Step 2: Pad 550 mm thick solid material into the reaction section through the reactor feed port;

[0070] Step 3: Start the electric heater to raise the temperature of the carbon particles in the heating section to 1200 °C for standby;

[0071] Step 4: Then introduce chlorine gas with a purity of 99.9% through the air inlet at the bottom of the reactor. After being evenly distributed by the air distribution chamber, the chlorine gas enters the heating section;

[0072] Step 5: The chlorine gas is heated to 1200 °C in the heating section and then enters the reaction section;

[0073] Step 6: When the chlorine gas passes through the reaction section, the solid material is blown up to form a fluidized state. After the chlorine gas reacts with the impurities in the material, it rises with the gas flow. After being depressurized by the expansion section and cooled by the jacket water to 500 °C (Ideal gas state equation PV = nRT, the temperature decreases when the volume expands), it enters the post-treatment system from the air outlet;

[0074] Step 7: After reacting for a period of time, the high-purity quartz sand product purified in the reaction section starts to be discharged through the discharge port into the product metering tank. At the same time, the top feed port starts to feed through the raw material metering tank, keeping the feeding and discharging rates of the reactor at 7.5 kg / min, and keeping the pressure difference between the upper and lower ends of the reaction chamber controlled at 8 kPa, so as to ensure the stability of the material layer level (i.e., w 进料 ≈w 出料 ), and avoid the destruction of the fluidized state.

[0075] The metal impurity content of the high-purity quartz sand product processed from the above examples can be effectively controlled within 20 ppm (for specific experimental data, refer to Table 2), meeting the requirements of the photovoltaic and semiconductor fields.

[0076] Table 2: Comparison of element content in Sample 2 before and after processing

[0077]

[0078] Example 3:

[0079] The deep purification equipment structure in this example is basically the same as that in Example 1, with the difference lying in the purification method; specifically: the purification method includes the following steps:

[0080] Step 1: Pre-dry the raw material quartz sand at 120 °C until its dew point < 40 °C is detected, and then measure the bulk density of the dried material, controlling its bulk density to be 1.7 g / cm 2 ;

[0081] Step 2: Pad 520 mm thick solid material into the reaction section through the reactor feed port;

[0082] Step 3: Start the electric heater to raise the temperature of the carbon particles in the heating section to 1000 °C for standby;

[0083] Step 4: Then introduce chlorine gas with a purity of 99.9% through the gas inlet at the bottom of the reactor. After being evenly distributed by the gas distribution chamber, the chlorine gas enters the heating section;

[0084] Step 5: The chlorine gas is heated to 1100 °C in the heating section and then enters the reaction section;

[0085] Step 6: When the chlorine gas passes through the reaction section, the solid material is blown up to form a fluidized state. After the chlorine gas reacts with the impurities in the material, it rises with the gas flow. After being depressurized through the expansion section and cooled by the jacket water to 400 °C (Ideal gas state equation PV = nRT, the temperature decreases when the volume expands), it enters the post-treatment system from the gas outlet;

[0086] Step 7: After reacting for a period of time, the high-purity quartz sand product purified in the reaction section starts to be discharged through the discharge port into the product metering tank. At the same time, the top feed port starts to feed through the raw material metering tank, maintaining the inlet and outlet rates of the reactor at 7 kg / min and controlling the pressure difference between the upper and lower ends of the reaction chamber at 6 kPa, so as to ensure the stability of the material layer level (i.e., w 进料 ≈w 出料 ), avoiding the destruction of the fluidized state.

[0087] The metal impurity content of the high-purity quartz sand products processed from the above embodiments can be effectively controlled within 20 ppm (specific experimental data are shown in Table 3), meeting the requirements of the photovoltaic and semiconductor fields.

[0088] Table 3: Comparison of element content in Sample 3 before and after processing

[0089] Element (ppm) Al Ca Co Cr Cu Fe K Li Mn Na Ni Ti Mg B ∑ Before processing 27.9 0.95 0.06 0.06 0.04 7.88 0.62 0.83 0.29 1.72 0.67 1.99 0.16 1.34 44.51 After processing 13.7 0.25 0.01 0.01 0.01 0.53 0.12 0.12 0.01 0.36 0.01 1.24 0.01 0.03 16.41

[0090] The embodiments described above are some, but not all, of the embodiments of the present invention. The detailed description of the embodiments of the present invention is not intended to limit the scope of the claimed invention, but merely represents selected embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts fall within the scope of protection of the present invention.

Claims

1. A deep purification device for high-purity quartz sand, characterized in that, It includes a vertical reactor shell. Inside the reactor shell, there are successively arranged from bottom to top a gas distribution chamber, an electric heating section, a reaction section, and an enlarged section. An air inlet is provided at the gas distribution chamber. A high-purity quartz sand feed port and an air outlet are arranged at the top of the enlarged section on the reactor shell. A cooling device is arranged inside and / or outside the enlarged section. A finished product discharge port is arranged at the bottom of the reaction section.

2. The deep purification equipment for high-purity quartz sand according to claim 1, characterized in that The heating section is heated by electrode energization and filled with spherical carbon particles.

3. The deep purification equipment for high-purity quartz sand according to claim 2, characterized in that, A gas distribution plate is arranged between the electric heating section and the reaction section. A plurality of air holes are evenly arranged on the gas distribution plate, and each air hole is equipped with a wind cap.

4. The deep purification equipment for high-purity quartz sand according to claim 2, wherein, Thermometers are respectively arranged at the gas distribution chamber, the reaction section, and the enlarged section.

5. The deep purification equipment for high-purity quartz sand according to claim 3, characterized in that, A weighing and metering tank is arranged at the top of the reactor shell. The metering tank conveys solid materials to the reaction section through the feed port in a spiral feeding form.

6. The deep purification equipment for high-purity quartz sand according to claim 4, characterized in that, The reactor shell successively includes a heat preservation layer, a high-temperature resistant layer, and a steel plate layer from the inside to the outside.

7. A method for deeply purifying high-purity quartz sand by using the deep purification equipment for high-purity quartz sand described in any one of claims 1 to 6, characterized in that, It includes the following steps: Step 1: Pre-dry the raw material quartz sand at 100-150°C until its dew point < 40°C is detected, and then measure the bulk density of the dried material, controlling the bulk density to be 1.5-1.85 g / cm 2 ; Step 2: Pad 500 ± 50 mm thick solid materials into the reaction section through the reactor feed port. Step 3: Start the electric heater to raise the temperature of the carbon particles in the heating section to 1000 - 1200 °C for standby. Step 4: Then introduce chlorine with a purity of 99.9% through the air inlet at the bottom of the reactor. After the chlorine is evenly distributed through the gas distribution chamber, it enters the heating section. Step 5: The chlorine is heated to 1000 - 1200 °C in the heating section and then enters the reaction section. Step 6: When the chlorine passes through the reaction section, the solid materials are blown up to form a fluidized state. After the chlorine reacts with the impurities in the materials, it rises with the air flow. After being depressurized through the enlarged section and cooled by the jacket water to 300 - 500 °C, it enters the post-treatment system from the air outlet. Step 7: After reacting for a period of time, the purified high-purity quartz sand product in the reaction section starts to be discharged through the discharge port to the product metering tank. At the same time, the top feed port starts to feed through the raw material metering tank to ensure the stable material level of the material layer and avoid damaging the fluidized state.

8. The method for deep purification of high-purity quartz sand according to claim 7, characterized in that: The chlorine gas flow rate is controlled to be: u mf <u0 < u t， where u0 is the chlorine gas flow rate, and u mf is the initial fluidization velocity, and u t is the escape velocity of the quartz sand particles; When the resistance of the gas flowing through the solid bed of the reactor is equal to the weight of the quartz sand particles, the particles in the bed start to flow, and the gas velocity at this time is the initial fluidization velocity u mf For quartz sand particles where d p is the average particle size of quartz sand particles, ρ p is the density of quartz sand particles, ρ is the density of chlorine gas, μ is the viscosity of chlorine gas, and g is the acceleration of gravity; When the gas flow rate > u mf At this time, the bed particles reach the fluidized state. If the gas flow rate is too large, the quartz sand particles will be carried out of the reactor. Therefore, it is necessary to simultaneously ensure that the gas flow rate is less than the escape velocity of the quartz sand particles That is: the chlorine gas flow rate is controlled as: u mf <u0<u t .

9. The method for deep purification of high-purity quartz sand according to claim 8, characterized in that: The chlorine gas flow rate is 0.01 - 0.05 m / s.

10. The method for deep purification of high-purity quartz sand according to claim 7, characterized in that: In Step 7: Keep the inlet and outlet rates of the reactor at 6.5 - 7.5 kg / min, and control the pressure difference between the upper and lower ends of the reaction chamber at 5 - 8 kPa.

Images