Preparation process of ultrahigh-purity 7N-grade synthetic quartz sand

Abstract

The invention relates to a preparation technology of ultra-high-purity 7N-grade synthetic quartz sand, belongs to the field of synthetic quartz sand preparation, and aims to solve the problems that in the preparation process of existing synthetic quartz sand, ultra-high-purity preparation of quartz sand cannot be carried out; the device solves the problems that in the prior art, multiple preparation steps of synthetic quartz sand cannot be completed through one device, the working efficiency is low, the preparation cost is high, and the energy consumption is high in the prior art, and comprises a device shell, a sealing door is installed on the device shell, and a hydraulic rod is fixedly installed on the bottom end face of the interior of the device shell; a mounting plate is fixedly connected to the top end of the hydraulic rod, an efficient stirring assembly is mounted on the mounting plate, and an energy-saving drying assembly is mounted on the mounting plate. Through cooperation of the efficient stirring assembly and the energy-saving drying assembly, treatment work of multiple steps can be efficiently completed, the structure is simple, cost is low, energy waste is effectively avoided, and the effects of saving cost and energy consumption are achieved.

Description

Technical Field

[0001] The invention relates to a process for preparing ultra-high purity 7N grade synthetic quartz sand, and belongs to the field of synthetic quartz sand preparation. Background Art

[0002] Synthetic quartz sand refers to a colorless, transparent, high-hardness, high-wear-resistant, and chemically stable quartz sand that is synthesized through a special process using high-purity silicon oxide as raw material. Compared with natural quartz sand, synthetic quartz sand has no impurities, no color difference, uniform particle size, and high hardness. It is suitable for high-precision semiconductor manufacturing and special fields. With the development of the Internet of Things, 5G, and information technology, the demand for high-purity quartz sand is increasing, and its application prospects are very broad.

[0003] In the preparation process of existing synthetic quartz sand, high-purity quartz sand ore is usually used as raw material. However, due to the complex composition of the ore and the type and content of impurities in natural quartz will directly affect the purity of the final product, it is impossible to purify the quartz sand to ultra-high purity, and thus it is impossible to prepare the quartz sand to ultra-high purity; and the preparation process of synthetic quartz sand is cumbersome, so it is necessary to use a variety of processing equipment to complete the preparation process of synthetic quartz sand, which leads to low work efficiency, high preparation cost and high energy consumption. Therefore, we have made improvements on this and proposed a preparation process for ultra-high purity 7N grade synthetic quartz sand. Summary of the invention

[0004] (I) The technical problem to be solved by the present invention is that the existing synthetic quartz sand cannot be prepared with ultra-high purity during the preparation process; and it is not possible to use one device to complete multiple preparation steps of synthetic quartz sand, resulting in low work efficiency, high preparation cost and high energy consumption.

[0005] (II) Technical solution In order to achieve the above-mentioned object of the invention, the present invention provides a process for preparing ultra-high purity 7N grade synthetic quartz sand, comprising the following steps: A. Solution preparation and reaction: Add ethanol and tetraethoxysilane to the integrated energy-saving treatment equipment, mix tetraethoxysilane and ethanol, and stir them evenly through the integrated energy-saving preparation device; during the stirring process, slowly add water and hydrochloric acid to perform hydrolysis and condensation reactions, and generate silicate; as the hydrolysis and condensation reactions proceed, the silicate begins to gel and form a sol, and as the reaction proceeds, the viscosity of the solution gradually increases, and finally a gel network structure is formed; B. Heat treatment: After the gel is gelled, the gel is dried by an integrated energy-saving preparation device to remove moisture from the gel; the dried gel is then calcined at high temperature. During the calcination process, the silica gel is converted into a dense silica material to obtain high-purity silica; C. Purification treatment: The silicon dioxide is acid-washed, water-washed, neutralized and dried through an integrated energy-saving preparation device; D. High temperature sintering: Silica is sintered at high temperature in a vacuum environment to further improve the purity of quartz sand. The sintered silica is crushed and screened to control the particle size and morphology to obtain ultra-high purity 7N grade synthetic quartz sand.

[0006] Wherein, in step A, the volume ratio of tetraethoxysilane:ethanol is 1:3-1:5, and the volume ratio of ethanol:water is 1:1-1:4.

[0007] Among them, the concentration of hydrochloric acid in step A is 0.1mol / L~1mol / L, and the amount of hydrochloric acid is 1-2ml. Hydrochloric acid plays a catalytic role in the reaction, helps promote the hydrolysis reaction and controls the pH value of the sol, and controls the pH value of the sol to be between 4 and 5.

[0008] Among them, the hydrolysis reaction formula in step A is: Si(OC2H5)4+4H2O→Si(OH)4+4C2H5OH, and the condensation reaction formula is Si(OH)4→Si-O-Si+H2O. As the reaction proceeds, the Si-O-Si bonds continue to increase, the viscosity of the solution gradually increases, and finally a gel network structure is formed.

[0009] Wherein, the drying temperature in step B is 50-150°C, and the drying time is 12-24 hours.

[0010] Wherein, the sintering temperature in step B is 1400-1600°C, and the sintering time is 3-6 hours.

[0011] The pickling solution used in step C is a mixed acid solution of concentrated nitric acid and concentrated hydrochloric acid, the volume ratio of concentrated nitric acid: concentrated hydrochloric acid is 1:3, and the neutralization solution used in step C is a sodium hydroxide solution.

[0012] Wherein, the calcination temperature in step D is 500-1000° C., and the calcination time is 4-48 hours.

[0013] The integrated energy-saving preparation device described in any one of steps A to C of the above-mentioned ultra-high purity 7N grade synthetic quartz sand preparation process comprises: The device shell has a sealing door installed on the device shell, a hydraulic rod is fixedly installed on the inner bottom end surface of the device shell, the top end of the hydraulic rod is fixedly connected to a mounting plate, a high-efficiency stirring component is installed on the mounting plate, and an energy-saving drying component is installed on the mounting plate. A positioning frame is welded and fixed on the inner bottom end surface of the device shell, a fourth spring is welded and fixed on the outer wall of the positioning frame, and a clamping rod is welded and fixed on the other end of the fourth spring, the clamping rod is slidably connected to the positioning frame, a processing frame is arranged in the positioning frame, a clamping groove is provided at the bottom side end of the processing frame, the end of the clamping rod is clamped and connected in the clamping groove, a drain pipe is connected to the bottom of the processing frame, the drain pipe is slidably connected to the bottom of the device shell, an electromagnetic valve is installed on the drain pipe, and the bottom end surface of the processing frame is in contact with the inner bottom end surface of the device shell.

[0014] Among them, the high-efficiency stirring assembly includes a support rod, the bottom end of the support rod is welded and fixed on the top surface of the mounting plate, a servo motor is welded and fixed on the top of the support rod, the output end of the servo motor is connected with a rotating shaft, the rotating shaft and the mounting plate are rotatably connected, a connecting rod is welded and fixed to the bottom end of the rotating shaft, a stirring rod is hinged on the connecting rod, a guide rod is welded and fixed on the stirring rod, a connecting plate is welded and fixed on the connecting rod, a first spring is welded and fixed on the bottom end surface of the connecting plate, a support plate is welded and fixed on the bottom end of the first spring, and the connecting rod is slidably connected to the support plate.

[0015] Among them, the cross-section of the connecting rod is rectangular, the connecting rod is connected to the center of the support plate, the stirring rods are arranged in four groups, the four groups of stirring rods are distributed on the connecting rod at equal angles, each group of stirring rods is distributed on the connecting rod at equal distances, and the guide rods are symmetrically distributed on both sides of the stirring rod.

[0016] Among them, a limit plate is welded and fixed on the support plate, a guide groove is opened on the limit plate, a guide groove is penetrated through the limit plate, the guide rod is limited and slidably connected in the guide groove, a push rod is welded and fixed on the top surface of the support plate, a liquid storage tank is welded and fixed on the mounting plate, a fixing pipe is connected to the top side end of the liquid storage tank, a push block is welded and fixed on the bottom surface of the liquid storage tank, a feeding pipe is connected to the bottom of the liquid storage tank, a magnetic sleeve is sleeved on the feeding pipe, the bottom end surface of the magnetic sleeve is in contact with the top surface of the support plate, and the support plate and the magnetic sleeve are magnetically adsorbed.

[0017] Among them, the top end surface of the limit plate is flush with the top end surface of the support plate, the limit plates are arranged in four groups, each group of limit plates is arranged with two limit plates, the four groups of limit plates are distributed at equal angles on the support plate, the two limit plates of each group are symmetrically distributed on both sides of each group of stirring rods, the guide grooves correspond to the guide rods one by one, the push rods and liquid storage tanks are arranged in four, four push rods are distributed at equal angles on the support plate, four liquid storage tanks are distributed at equal angles on the mounting plate, the liquid storage tanks correspond to the push blocks and the discharge pipes one by one respectively, the bottom end surface of the liquid storage tanks is flush with the bottom end surface of the mounting plate, the end surface of the push block is arc-shaped, and the discharge pipes correspond to the magnetic sleeves one by one.

[0018] Among them, the energy-saving drying component includes a second spring, a first magnetic plate, a first filter plate and a dehumidification screen plate, one end of the second spring is welded and fixed on the rotating shaft, the other end of the second spring is welded and fixed with a clamping block, the rotating shaft is rotatably connected with a sleeve through a bearing, a limiting groove is provided in the sleeve, one end of the clamping block is rotatably connected to the rotating shaft, the other end of the clamping block is engaged and connected in the limiting groove, a first gear is welded and fixed on the sleeve, a second gear is meshed and connected to the first gear, a driven shaft is welded and fixed on the second gear, an exhaust fan is welded and fixed on the driven shaft, the bottom end of the driven shaft is fixedly connected with a rubber rod, and an insulation box is welded and fixed on the mounting plate.

[0019] Among them, the second springs are distributed at equal angles on the rotating shaft, the second springs correspond to the blocking blocks one by one, the inner diameter of the sleeve is larger than the diameter of the rotating shaft, the limiting grooves are distributed at equal angles in the sleeve, the internal space of the limiting grooves is a right triangle, the second gears are symmetrically distributed on both sides of the first gear, and the second gears correspond to the temperature isolation box one by one through the driven shaft.

[0020] Among them, a first ventilation pipe is fixedly connected to the top of the thermal insulation box, a fixed mesh plate is welded and fixed in the first ventilation pipe, the driven shaft is rotatably connected to the fixed mesh plate, the fixed mesh plate is a large-aperture mesh plate, and a second ventilation pipe is connected to the bottom of the thermal insulation box, the bottom of the second ventilation pipe is inclined, an electric heating pipe is installed in the thermal insulation box, a through groove is opened on the thermal insulation box, a positioning rod is welded and fixed on the outer wall of the thermal insulation box, a third spring is welded and fixed in the positioning rod, a stopper is welded and fixed to the other end of the third spring, and the stopper is limited and slidably connected in the positioning rod.

[0021] Among them, the electric heating tubes are equidistantly distributed in the thermal insulation box, the positioning rod is fixed at the middle part of the side end of the thermal insulation box, the through grooves are symmetrically distributed on the upper and lower sides of the positioning rod, the third springs are symmetrically distributed on both sides inside the positioning rod, the third springs correspond to the blocks one by one, and the end cross-section of the block is a right-angled trapezoid.

[0022] Among them, a first positioning groove is opened through the first magnetic plate, the positioning rod is limited and slidably connected in the first positioning groove, a second positioning groove is opened on the first magnetic plate, the side ends of the first filter plate and the side ends of the dehumidification screen plate are fixedly connected with the second magnetic plate, the second magnetic plate is snap-connected in the second positioning groove, a collecting groove is opened on the first filter plate, the first magnetic plate is fitted with the insulation box, the insulation box and the first magnetic plate are magnetically adsorbed, the cross-section of the positioning rod and the cross-section of the first positioning groove are both rectangular, the collecting grooves are distributed at equal angles on the first filter plate, and the top end surface of the first filter plate is fitted with the bottom end surface of the rubber rod.

[0023] Beneficial Effects The invention provides a process for preparing ultra-high purity 7N grade synthetic quartz sand, which has the following beneficial effects: 1. By mixing tetraethoxysilane with ethanol and combining it with an integrated energy-saving preparation device, high-purity silica raw materials can be easily and efficiently prepared under mild conditions. Selecting relatively pure silica raw materials as the initial raw materials can greatly reduce the difficulty of the subsequent purification process, thereby effectively improving the purity and preparation efficiency of quartz sand. Combined with subsequent multiple purification treatments, the efficient preparation of ultra-high purity 7N grade synthetic quartz sand is conveniently and stably achieved.

[0024] 2. Through the clockwise rotation of the set rotating shaft, the various stirring rods can be driven to rotate stably through the connecting rod without driving the energy-saving drying component. At the same time, the connecting rod can drive the support plate to rotate synchronously, and then drive the various push rods and various push blocks to contact intermittently. Combined with the first spring, it can drive the support plate to automatically and stably reciprocate up and down during the rotation process. The stirring rod on the guide rod can be driven to swing up and down during the rotation process through the guide groove on the limit plate, thereby achieving efficient and uniform mixing of tetraethoxysilane and ethanol and mixing effect, and effectively improving the preparation efficiency; and during the rotation of the support plate, it can drive the guide grooves on each group of limit plates to be intermittently aligned with each feed pipe. At this time, the water and hydrochloric acid in the liquid storage tank are automatically and intermittently transported to the processing frame, and efficient and uniform mixing can be performed at the same time, ensuring the stability and efficiency of the hydrolysis and condensation reactions. Moreover, under the guiding effect of the guide groove, splashing during the transportation process can be avoided to cause environmental pollution.

[0025] 3. Driven by the hydraulic rod, the high-efficiency stirring assembly can be lifted and separated from the processing frame in combination with the mounting plate. At this time, under the counterclockwise rotation of the rotating shaft, the first gear on the sleeve can be driven to rotate stably through the block, and then the exhaust fan on the driven shaft can be driven to rotate stably in the corresponding first ventilation duct through the second gears on both sides, thereby driving the air to circulate inside the device; and during the air flow, the air can be filtered, dehumidified and heated through the first filter plate, the dehumidification mesh plate and the electric heating tube, thereby achieving efficient drying of the reacted gel, and utilizing the circulating flow of air to effectively avoid heat loss, avoid energy waste, and save energy consumption.

[0026] 4. Through the rotation of the exhaust fan, the rubber rod can be driven to rotate synchronously through the driven shaft, and then the dust and impurities filtered on the first filter plate can be moved to the collection tank for automatic collection, thereby realizing the automatic cleaning of the first filter plate and avoiding the problem that the first filter plate is easily blocked during long-term operation, thereby affecting the subsequent filtering work; and by utilizing the cooperation of the positioning rod and the block, combined with the first magnetic plate and the second magnetic plate, the first filter plate and the dehumidification screen plate can be easily disassembled and installed, thereby ensuring the convenience of subsequent cleaning and replacement of the first filter plate and the dehumidification screen plate, thereby ensuring the stability of the first filter plate and the dehumidification screen plate in a long-term working state and improving the service life of the device.

[0027] 5. The servo motor can be used to control the rotation of the rotating shaft to rotate forward and reverse, so that the efficient stirring component can be driven alone or the efficient stirring component and the energy-saving drying component can be driven at the same time. By driving the efficient stirring component alone, tetraethoxysilane and ethanol can be mixed, water and hydrochloric acid can be automatically and intermittently conveyed, and subsequent efficient mixing can be performed. By lifting the efficient stirring component and driving the energy-saving drying component, the gel formed by the reaction can be dried in an energy-saving and efficient manner. Similarly, by driving the efficient stirring component through the rotating shaft, the mixed acid solution, water and neutralization solution can be automatically and intermittently conveyed, and the silicon dioxide can be acid-washed, washed with water and neutralized in turn in combination with the efficient stirring component. Moreover, by driving the efficient stirring component and the energy-saving drying component at the same time, the silicon dioxide after purification is stirred and dried at the same time, which effectively improves the drying efficiency and drying effect of the silicon dioxide and effectively improves the working efficiency of the device. In summary, through the cooperation of the efficient stirring component and the energy-saving drying component, multiple steps of processing can be completed efficiently, the structure is simple, the cost is low, and energy waste is effectively avoided, achieving the effect of saving cost and saving energy consumption. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0029] Figure 1 It is a schematic diagram of the process flow of the present invention; Figure 2 It is a schematic diagram of the three-dimensional structure of the housing of the device of the present invention; Figure 3 This is a schematic diagram of the connection structure between the support rod and the servo motor of the present invention; Figure 4 This is a schematic diagram of the connection structure between the first gear and the second gear of the present invention; Figure 5 It is a schematic diagram of the connection structure between the liquid storage tank and the push block of the present invention; Figure 6 It is a schematic diagram of the connection structure between the hydraulic rod and the mounting plate of the present invention; Figure 7 This is a schematic diagram of the connection structure between the support plate and the limiting plate of the present invention; Figure 8 For the present invention Figure 7 The enlarged structural diagram at A in the middle; Fig. 9 For the present invention Figure 7 The enlarged structural diagram at B in the middle; Fig.10 This is a schematic diagram of the connection structure of the connecting rod and the stirring rod of the present invention; Fig.11 This is a schematic diagram of the main cross-sectional structure of the sleeve of the present invention; Fig.12 It is a schematic diagram of the top view of the sleeve structure of the present invention; Fig.13 This is a schematic diagram of the main cross-sectional structure of the first ventilation pipe of the present invention; Fig.14 This is a schematic diagram of the connection structure of the third spring and the stopper of the present invention; Fig.15 This is a schematic diagram of the connection structure between the heat insulation box and the electric heating tube of the present invention; Fig.16 This is a schematic diagram of the connection structure between the first magnetic plate and the first positioning groove of the present invention; Fig.17 This is a schematic diagram of the connection structure between the second magnetic plate and the filter plate of the present invention; Fig.18 This is a schematic diagram of the connection structure between the processing frame and the drain pipe of the present invention; Fig.19 It is a schematic diagram of the connection structure between the liquid discharge pipe and the device housing of the present invention.

[0030] In the figure: 1. device housing; 2. sealing door; 3. hydraulic rod; 4. mounting plate; 5. high-efficiency stirring assembly; 501. support rod; 502. servo motor; 503. rotating shaft; 504. connecting rod; 505. stirring rod; 506. guide rod; 507. connecting plate; 508. first spring; 509. supporting plate; 510. limiting plate; 511. guide groove; 512. guide groove; 513. push rod; 514. liquid storage tank; 515. fixed pipe; 516. push block; 517. feeding pipe; 518. magnetic sleeve; 6. energy-saving drying assembly; 601. second spring; 602. block; 603. sleeve; 604. limiting groove; 605. first Gear; 606, second gear; 607, driven shaft; 608, exhaust fan; 609, temperature insulation box; 610, first ventilation duct; 611, fixed mesh plate; 612, second ventilation duct; 613, electric heating tube; 614, through groove; 615, positioning rod; 616, third spring; 617, stopper; 618, first magnetic plate; 619, first positioning groove; 620, second positioning groove; 621, second magnetic plate; 622, first filter plate; 623, collecting groove; 624, dehumidification mesh plate; 625, rubber rod; 7, positioning frame; 8, fourth spring; 9, clamping rod; 10, processing frame; 11, clamping groove; 12, drain pipe; 13, second filter plate. DETAILED DESCRIPTION

[0031] The specific implementation of the present invention is further described in detail below in conjunction with the accompanying drawings and examples of the specification. The following examples are only used to illustrate the present invention, but cannot be used to limit the scope of the present invention.

[0032] Embodiment 1: like Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 5 , Figure 6 , Figure 7 , Figure 8 , Fig. 9 , Fig.10 , Fig.11 , Fig.12 , Fig.13 , Fig.14 , Fig.15 , Fig.16 , Fig.17 , Fig.18 , Fig.19 As shown, this embodiment proposes a process for preparing ultra-high purity 7N grade synthetic quartz sand, comprising the following steps: A. Solution preparation and reaction: Add ethanol and tetraethoxysilane to the integrated energy-saving treatment equipment, mix tetraethoxysilane and ethanol, and stir them evenly through the integrated energy-saving preparation device; during the stirring process, slowly add water and hydrochloric acid to perform hydrolysis and condensation reactions, and generate silicate; as the hydrolysis and condensation reactions proceed, the silicate begins to gel and form a sol, and as the reaction proceeds, the viscosity of the solution gradually increases, and finally a gel network structure is formed; B. Heat treatment: After the gel is gelled, the gel is dried by an integrated energy-saving preparation device to remove moisture from the gel; the dried gel is then calcined at high temperature. During the calcination process, the silica gel is converted into a dense silica material to obtain high-purity silica; C. Purification treatment: The silicon dioxide is acid-washed, water-washed, neutralized and dried through an integrated energy-saving preparation device; D. High temperature sintering: Silica is sintered at high temperature in a vacuum environment to further improve the purity of quartz sand. The sintered silica is crushed and screened to control the particle size and morphology to obtain ultra-high purity 7N grade synthetic quartz sand.

[0033] In step A, the volume ratio of tetraethoxysilane: ethanol is 1:3-1:5, and the volume ratio of ethanol: water is 1:1-1:4; the concentration of hydrochloric acid in step A is 0.1 mol / L-1 mol / L, and the amount of hydrochloric acid is 1-2 ml. Hydrochloric acid plays a catalytic role in the reaction, helps promote the hydrolysis reaction and controls the pH value of the sol, and controls the pH value of the sol between 4 and 5; the hydrolysis reaction formula in step A is: Si(OC2H5)4+4H2O→Si(OH)4+4C2H5OH, and the condensation reaction formula is Si(OH)4→Si-O-Si+H2O. As the reaction proceeds, the Si-O-Si bonds continue to increase, the viscosity of the solution gradually increases, and finally a gel network structure is formed.

[0034] The drying temperature in step B is 50-150°C, and the drying time is 12-24 hours; the sintering temperature in step B is 1400-1600°C, and the sintering time is 3-6 hours.

[0035] The pickling solution used in step C is a mixed acid solution of concentrated nitric acid and concentrated hydrochloric acid, the volume ratio of concentrated nitric acid: concentrated hydrochloric acid is 1:3, and the neutralization solution used in step C is a sodium hydroxide solution.

[0036] The calcination temperature in step D is 500-1000° C. and the calcination time is 4-48 hours.

[0037] The integrated energy-saving preparation device described in any one of steps A to C of the above-mentioned ultra-high purity 7N grade synthetic quartz sand preparation process comprises: The device shell 1 is provided with a sealing door 2, a hydraulic rod 3 is fixedly installed on the inner bottom end surface of the device shell 1, a mounting plate 4 is fixedly connected to the top of the hydraulic rod 3, a high-efficiency stirring component 5 is installed on the mounting plate 4, an energy-saving drying component 6 is installed on the mounting plate 4, a positioning frame 7 is welded and fixed on the inner bottom end surface of the device shell 1, a fourth spring 8 is welded and fixed on the outer wall of the positioning frame 7, a clamping rod 9 is welded and fixed on the other end of the fourth spring 8, the clamping rod 9 penetrates and is slidably connected to the positioning frame 7, a processing frame 10 is arranged in the positioning frame 7, a clamping groove 11 is provided at the bottom side end of the processing frame 10, the end of the clamping rod 9 is clamped and connected in the clamping groove 11, a drain pipe 12 is connected to the bottom of the processing frame 10, the drain pipe 12 penetrates and is slidably connected to the bottom of the device shell 1, a solenoid valve is installed on the drain pipe 12, the bottom end surface of the processing frame 10 is fitted with the inner bottom end surface of the device shell 1, by mixing tetraethoxysilane with ethanol, Furthermore, the high-efficiency stirring component 5 can complete the mixing of tetraethoxysilane and ethanol, the automatic intermittent delivery of water and hydrochloric acid, and the subsequent high-efficiency mixing work under mild conditions; and the energy-saving drying component 6 can perform energy-saving and high-efficiency drying treatment on the gel formed by the reaction; at the same time, the mixed acid solution, water and neutralization solution can be automatically and intermittently delivered, and the silicon dioxide can be acid-washed, water-washed and neutralized in turn in combination with the high-efficiency stirring component 5; and by driving the high-efficiency stirring component 5 and the energy-saving drying component 6 at the same time, the silicon dioxide after the purification treatment is stirred and dried at the same time, which effectively improves the drying efficiency and drying effect of the silicon dioxide, and effectively improves the working efficiency of the device; in summary, through the cooperation of the high-efficiency stirring component 5 and the energy-saving drying component 6, multiple steps of processing work can be completed efficiently, the structure is simple, the cost is low, and the waste of energy is effectively avoided, achieving the effect of saving cost and saving energy consumption.

[0038] Embodiment 2: The solution in Example 1 is further introduced below in combination with a specific working method, as described below: like Figure 3 , Figure 4 , Figure 5 , Figure 6 , Figure 7 , Figure 8 , Fig. 9 and Fig.10As shown, as a preferred embodiment, on the basis of the above method, further, the high-efficiency stirring component 5 includes a support rod 501, the bottom end of the support rod 501 is welded and fixed on the top surface of the mounting plate 4, the top of the support rod 501 is welded and fixed with a servo motor 502, the output end of the servo motor 502 is connected with a rotating shaft 503, the rotating shaft 503 is rotatably connected with the mounting plate 4, the bottom end of the rotating shaft 503 is welded and fixed with a connecting rod 504, a stirring rod 505 is hinged on the connecting rod 504, a guide rod 506 is welded and fixed on the stirring rod 505, a connecting plate 507 is welded and fixed on the connecting rod 504, a first spring 508 is welded and fixed on the bottom end surface of the connecting plate 507, and the first spring 50 A support plate 509 is welded and fixed to the bottom end of 8, and a connecting rod 504 is slidably connected to the support plate 509. The cross-section of the connecting rod 504 is rectangular, and the connecting rod 504 is connected to the center of the support plate 509. Four groups of stirring rods 505 are arranged, and the four groups of stirring rods 505 are distributed at equal angles on the connecting rod 504. Each group of stirring rods 505 is equidistantly distributed on the connecting rod 504, and the guide rods 506 are symmetrically distributed on both sides of the stirring rods 505. By utilizing the clockwise rotation of the rotating shaft 503, the connecting rod 504 can drive each stirring rod 505 to rotate stably without driving the energy-saving drying component 6, thereby stirring tetraethoxysilane and ethanol, thereby ensuring the stability of subsequent reaction preparation work.

[0039] like Figure 5 , Figure 6 , Figure 7 , Figure 8 , Fig. 9 and Fig.10As shown, as a preferred embodiment, on the basis of the above method, further, a limit plate 510 is welded and fixed on the support plate 509, a guide groove 511 is opened on the limit plate 510, a guide groove 512 is opened through the limit plate 510, and the guide rod 506 is limited and slidably connected in the guide groove 512, a push rod 513 is welded and fixed on the top surface of the support plate 509, a liquid storage tank 514 is welded and fixed on the mounting plate 4, a fixing pipe 515 is connected to the top side end of the liquid storage tank 514, a push block 516 is welded and fixed on the bottom end surface of the liquid storage tank 514, and a feed pipe 517 is connected to the bottom of the liquid storage tank 514. The upper sleeve is provided with a magnetic sleeve 518, the bottom end surface of the magnetic sleeve 518 is in contact with the top end surface of the support plate 509, the support plate 509 and the magnetic sleeve 518 are attracted by magnetism, the top end surface of the limit plate 510 is flush with the top end surface of the support plate 509, and the limit plates 510 are provided in four groups, each group of limit plates 510 is provided with two, and the four groups of limit plates 510 are distributed at equal angles on the support plate 509, and the two limit plates 510 of each group are symmetrically distributed on both sides of each group of stirring rods 505, the guide grooves 512 correspond to the guide rods 506 one by one, and the push rods 513 and the liquid storage tank 514 are provided with four, and the four push rods 513 are distributed at equal angles on the support plate 509. On the plate 509, four liquid storage tanks 514 are distributed at equal angles on the mounting plate 4, and the liquid storage tanks 514 correspond to the push blocks 516 and the feed tubes 517 one by one, respectively. The bottom end surface of the liquid storage tank 514 is flush with the bottom end surface of the mounting plate 4, the end surface of the push block 516 is arc-shaped, and the feed tube 517 corresponds to the magnetic sleeve 518 one by one. The connecting rod 504 can drive the support plate 509 to rotate synchronously, and then can drive each push rod 513 and each push block 516 to contact intermittently, and combined with the first spring 508, it can drive the support plate 509 to perform automatic and stable up and down reciprocating motion during the rotation process, and can be brought to the guide groove 512 on the limit plate 510. The stirring rod 505 on the movable guide rod 506 swings up and down during the rotation process, thereby achieving efficient and uniform mixing of tetraethoxysilane and ethanol and a mixing effect, and effectively improving the preparation efficiency; and during the rotation of the support plate 509, it can drive the guide grooves 511 on each group of limit plates 510 to be intermittently aligned with each feed pipe 517. At this time, the water and hydrochloric acid in the liquid storage tank 514 are automatically and intermittently transported to the processing frame 10, and at the same time, efficient and uniform mixing can be performed, ensuring the stability and efficiency of the hydrolysis and condensation reactions, and under the guiding effect of the guide groove 511, splashing during the transportation process can be avoided to cause environmental pollution.

[0040] like Figure 3 , Figure 4 , Fig.11 , Fig.12 , Fig.13 and Fig.14As shown, as a preferred embodiment, on the basis of the above method, further, the energy-saving drying component 6 includes a second spring 601, a first magnetic plate 618, a first filter plate 622 and a moisture removal screen plate 624, one end of the second spring 601 is welded and fixed on the rotating shaft 503, and the other end of the second spring 601 is welded and fixed with a block 602, and the rotating shaft 503 is rotatably connected with a sleeve 603 through a bearing, and a limiting groove 604 is provided in the sleeve 603, and one end of the block 602 is rotatably connected to the rotating shaft 503 The other end of the card block 602 is engaged and connected in the limit groove 604, the sleeve 603 is welded and fixed with a first gear 605, the first gear 605 is meshed and connected with a second gear 606, the second gear 606 is welded and fixed with a driven shaft 607, the driven shaft 607 is welded and fixed with an exhaust fan 608, the bottom end of the driven shaft 607 is fixedly connected with a rubber rod 625, the mounting plate 4 is welded and fixed with a temperature isolation box 609, the second spring 601 is equiangularly distributed on the rotating shaft 503, and the second spring 601 and the card block 606 are connected. 02 one-to-one correspondence, the inner diameter of the sleeve 603 is larger than the diameter of the rotating shaft 503, the limiting grooves 604 are distributed at equal angles in the sleeve 603, the internal space of the limiting grooves 604 is a right triangle, the second gear 606 is symmetrically distributed on both sides of the first gear 605, the second gear 606 is one-to-one correspondence with the insulation box 609 through the driven shaft 607, the top of the insulation box 609 is fixedly connected with a first ventilation pipe 610, a fixed mesh plate 611 is welded and fixed in the first ventilation pipe 610, and the driven shaft 607 is rotatably connected to the fixed mesh plate On the plate 611, the fixed mesh plate 611 is a large-aperture mesh plate, and the bottom of the temperature isolation box 609 is connected to a second ventilation duct 612. The bottom of the second ventilation duct 612 is inclined. Under the counterclockwise rotation of the rotating shaft 503, the first gear 605 on the sleeve 603 can be driven to rotate stably through the block 602, and then the exhaust fan 608 on the driven shaft 607 can be driven to rotate stably in the corresponding first ventilation duct 610 through the second gears 606 on both sides, thereby driving the air to circulate inside the device.

[0041] like Figure 4 , Figure 5 , Fig.14 and Fig.15As shown, as a preferred embodiment, on the basis of the above-mentioned method, further, an electric heating tube 613 is installed in the insulation box 609, a through groove 614 is opened on the insulation box 609, a positioning rod 615 is welded and fixed on the outer wall of the insulation box 609, a third spring 616 is welded and fixed in the positioning rod 615, a stopper 617 is welded and fixed at the other end of the third spring 616, the stopper 617 is limitedly slidably connected in the positioning rod 615, the electric heating tubes 613 are equidistantly distributed in the insulation box 609, the positioning rod 615 is fixed in the middle part of the side end of the insulation box 609, and the through grooves 614 are symmetrically distributed in the positioning rod 615. On the upper and lower sides of the positioning rod 615, the third spring 616 is symmetrically distributed on both sides inside the positioning rod 615, and the third spring 616 corresponds to the block 617 one by one. The end cross-section of the block 617 is a right-angled trapezoid. By utilizing the cooperation of the positioning rod 615 and the block 617, combined with the first magnetic plate 618 and the second magnetic plate 621, the first filter plate 622 and the dehumidification screen plate 624 can be easily disassembled and installed, thereby ensuring the convenience of subsequent cleaning and replacement of the first filter plate 622 and the dehumidification screen plate 624, thereby ensuring the stability of the first filter plate 622 and the dehumidification screen plate 624 in long-term working conditions.

[0042] like Figure 4 , Fig.16 and Fig.17 As shown, as a preferred embodiment, on the basis of the above method, further, a first positioning groove 619 is opened on the first magnetic plate 618, the positioning rod 615 is limitedly slidably connected in the first positioning groove 619, the first magnetic plate 618 is opened with a second positioning groove 620, the side end of the first filter plate 622 and the side end of the dehumidification screen plate 624 are fixedly connected with the second magnetic plate 621, the second magnetic plate 621 is snap-connected in the second positioning groove 620, the first filter plate 622 is opened with a collecting groove 623, the first magnetic plate 618 is in contact with the insulation box 609, and the insulation box 609 is in contact with the first The magnetic plates 618 are magnetically adsorbed to each other, the cross-sections of the positioning rod 615 and the first positioning groove 619 are both rectangular, the collecting grooves 623 are equiangularly distributed on the first filter plate 622, and the top end surface of the first filter plate 622 fits with the bottom end surface of the rubber rod 625. During the air flow, the air can be filtered, dehumidified and heated by the first filter plate 622, the dehumidification mesh plate 624 and the electric heating tube 613, thereby achieving efficient drying of the reacted gel, and utilizing the circulating flow of air to effectively avoid heat loss, avoid energy waste, and save energy consumption.

[0043] Embodiment 3: The schemes in Example 1 and Example 2 are further introduced below in combination with specific working methods, as described below for details: Specifically, when the ultra-high purity 7N grade synthetic quartz sand preparation process is working: first, the staff can open the sealing door 2 on the device housing 1 and drive the hydraulic rod 3 in the device housing 1. At this time, the hydraulic rod 3 can push the high-efficiency stirring component 5 and the energy-saving drying component 6 to move upward through the mounting plate 4, and then can drive the high-efficiency stirring component 5 to move out of the processing frame 10. At this time, the staff can transport the tetraethoxysilane and ethanol with a good ratio into the processing frame 10, and then drive the hydraulic rod 3 and the servo motor 502, and close the sealing door 2 on the device housing 1. At this time, the hydraulic rod 3 can drive the high-efficiency stirring component 5 to move downward through the mounting plate 4. In the processing frame 10, under the driving action of the servo motor 502, the rotating shaft 503 can be driven to rotate stably clockwise, and then the support plate 509 can be driven to move synchronously through the connecting rod 504. At this time, under the rotation action of the rotating shaft 503, each stirring rod 505 can be driven to rotate stably; and when the rotating shaft 503 rotates clockwise, it can drive each block 602 to move along the inclined surface of the limiting groove 604 inside the sleeve 603. At this time, the limiting groove 604 cannot block the movement of the block 602. Therefore, the clockwise rotation of the rotating shaft 503 will not drive the sleeve 603 to rotate synchronously, so it will not drive the energy-saving drying component 6.

[0044] At the same time, during the synchronous rotation of the support plate 509, the support plate 509 can drive each push rod 513 to intermittently contact with the push block 516 at the bottom of each liquid storage tank 514. When the push rod 513 contacts the push block 516, under the guidance of the arc surface of the push block 516, the push rod 513 in the rotation process can be automatically moved downward. The movement of the push rod 513 can push the support plate 509 to move downward synchronously. When the push rod 513 moves away from the push block 516, the support plate 509 can be driven by the elastic action of the first spring 508 on the connecting plate 507. 509 moves upward to reset, and so on. During the process of the connecting rod 504 on the rotating shaft 503 driving the support plate 509 to rotate, the support plate 509 can automatically and stably reciprocate up and down, thereby driving the groups of limit plates 510 on the support plate 509 to perform synchronous reciprocating up and down movements. The up and down reciprocating movement of the limit plates 510 can drive the stirring rod 505 on the guide rod 506 to swing up and down during the rotation through the guide groove 512, thereby achieving efficient and uniform mixing of tetraethoxysilane and ethanol and a mixing effect, and effectively improving the preparation efficiency.

[0045] After tetraethoxysilane and ethanol are evenly mixed, the staff can open the sealed door 2 again, and transport the proportioned water and hydrochloric acid to the two liquid storage tanks 514 through the fixed tube 515. The sealed door 2 can be closed after the transportation. At this time, during the continuous rotation and up and down reciprocating motion of the support plate 509, the support plate 509 is always in contact with the magnetic sleeve 518, so the support plate 509 can drive the guide grooves 511 on each group of limiting plates 510 to be intermittently aligned with the discharge pipe 517 at the bottom of the liquid storage tank 514. At this time, the water and hydrochloric acid in the liquid storage tank 514 can be automatically and intermittently transported to the processing frame 10 through the guide grooves 511 on each group of limiting plates 510, and combined with the continuous movement of each stirring rod 505, efficient and uniform mixing can be carried out at the same time to ensure the stability and efficiency of the hydrolysis and condensation reactions, and under the guiding effect of the guide grooves 511, splashing during transportation can be avoided to cause environmental pollution.

[0046] After mixing, the staff can use the hydraulic rod 3 to push the high-efficiency stirring component 5 on the mounting plate 4 to move away from the processing frame 10. When the mixed solution reacts and forms a gel, the rotating shaft 503 at the output end of the servo motor 502 can be driven to rotate counterclockwise. At this time, the internal limit groove 604 of the sleeve 603 can block the movement direction of the block 602. Therefore, the rotating shaft 503 can push the sleeve 603 to rotate synchronously through the block 602, and then the second gears 606 on both sides can be driven to rotate simultaneously through the first gear 605. At this time, the second gear 606 can drive the exhaust fans 608 on both sides to rotate stably in the corresponding first ventilation pipe 610 through the driven shaft 607, so that the air can be sucked and then discharged through the temperature isolation box 609 and the second ventilation pipe 612, driving the air to circulate inside the device. At this time, the exhausted air is facing the processing frame 10.

[0047] During the air flow process, the air can be filtered, dehumidified and heated through the first filter plate 622, the dehumidification mesh plate 624 and the electric heating tube 613, thereby achieving efficient drying of the gel after the reaction. The circulation of air can effectively avoid heat loss, energy waste and energy consumption. In addition, during the rotation of the driven shaft 607, the rubber rod 625 can be driven to rotate synchronously, so that the dust and impurities filtered on the first filter plate 622 can be moved to the collection tank 623 for automatic collection, thereby achieving automatic cleaning of the first filter plate 622.

[0048] After the gel is dried, the staff can open the sealing door 2 and pull the clamping rod 9 on the positioning frame 7. At this time, the clamping rod 9 moves out of the clamping slot 11 on the processing frame 10, and then the processing frame 10 can be taken out. At this time, the gel can be transported to the calcination equipment for high-temperature calcination to obtain high-purity silica. Then the staff can transport the silica to the cleaned processing frame 10 again. Through the same operation, first pull the clamping rod 9 on the positioning frame 7 outward, and place the processing frame 10 in the positioning frame 7, and then release the clamping rod 9. At this time, under the elastic action of the fourth spring 8, the clamping rod 9 can be driven to automatically engage with the clamping slot 11 on the processing frame 10, completing the clamping and fixation of the processing frame 10, and ensuring the stability of the subsequent working state of the processing frame 10.

[0049] Since two of the four liquid storage tanks 514 have been used, one for conveying water and the other for conveying hydrochloric acid, the staff can convey the mixed acid solution to be used to the third liquid storage tank 514. In summary, by driving the high-efficiency stirring component 5 alone, the intermittent conveying of the mixed acid solution and the uniform mixing of the mixed acid solution and silicon dioxide can be achieved to realize the pickling work. After the pickling is completed, the solenoid valve on the drain pipe 12 can be opened. Under the filtering action of the second filter plate 13, the mixed acid solution can be discharged, and then the solenoid valve is closed, and then water is conveyed to the liquid storage tank 514 again, and the silicon dioxide after pickling is washed with water, and then the water is discharged. At this time, the staff can convey the neutralization solution to the fourth liquid storage tank 514 and neutralize the silicon dioxide.

[0050] After the silicon dioxide has been pickled, washed with water and neutralized, the servo motor 502 can be driven again to control the driving rotating shaft 503 to rotate counterclockwise, thereby driving the high-efficiency stirring component 5 and the energy-saving drying component 6 at the same time, so that the purified silicon dioxide can be stirred and dried at the same time, effectively improving the drying efficiency and drying effect of the silicon dioxide and the working efficiency of the device; then the staff can take out the treated silicon dioxide through repeated operations, and carry out subsequent high-temperature sintering, crushing and screening processes to obtain ultra-high purity 7N grade synthetic quartz sand.

[0051] After the device is finished working, the staff can press the stop block 617 to make it move into the positioning rod 615. At this time, the first magnetic plate 618 is not blocked and can be pulled out of the thermal insulation box 609. At this time, the first magnetic plate 618 can drive the first filter plate 622 and the dehumidification screen plate 624 on the two second magnetic plates 621 to move synchronously out of the thermal insulation box 609 through magnetism. Subsequently, under the magnetic effect of the second magnetic plate 621, the first filter plate 622 and the dehumidification screen plate 624 can be easily disassembled and assembled with the first magnetic plate 618, so that the first filter plate 622 and the dehumidification screen plate 624 can be cleaned and replaced conveniently and stably. After cleaning and replacing, the first filter plate 622 and the dehumidification screen plate 624 can be easily disassembled and assembled with the first magnetic plate 618. Plate 624 can be snapped into the second positioning groove 620 on the first magnetic plate 618 through the second magnetic plate 621, and then the first filter plate 622 and the moisture-removing screen plate 624 can be respectively inserted into the two through grooves 614 on the thermal insulation box 609. During the insertion process, the first magnetic plate 618 can also push and squeeze the block 617 to move it into the positioning rod 615 until the first magnetic plate 618 passes over the block 617. At this time, the third spring 616 can drive the block 617 to automatically move outward and reset. Combined with the positioning rod 615 and the first positioning groove 619 on the first magnetic plate 618, the first magnetic plate 618 can be easily snapped into place to ensure the stability of its subsequent working state.

[0052] The above embodiments are only used to illustrate the present invention, but not to limit the present invention. Although the present invention is described in detail with reference to the embodiments, it should be understood by those skilled in the art that various combinations, modifications or equivalent substitutions of the technical solutions of the present invention do not depart from the spirit and scope of the technical solutions of the present invention, and should be included in the scope of the claims of the present invention.

Claims

1. A process for preparing ultra-high purity 7N grade synthetic quartz sand, characterized in that: The following steps are involved: A. Solution preparation and reaction: Add ethanol and tetraethoxysilane to the integrated energy-saving treatment equipment, mix tetraethoxysilane and ethanol, and stir them evenly through the integrated energy-saving preparation device; during the stirring process, slowly add water and hydrochloric acid to perform hydrolysis and condensation reactions, and generate silicate; as the hydrolysis and condensation reactions proceed, the silicate begins to gel and form a sol, and as the reaction proceeds, the viscosity of the solution gradually increases, and finally a gel network structure is formed; B. Heat treatment: After the gel is gelled, the gel is dried by an integrated energy-saving preparation device to remove moisture from the gel; the dried gel is then calcined at high temperature. During the calcination process, the silica gel is converted into a dense silica material to obtain high-purity silica; C. Purification treatment: The silicon dioxide is acid-washed, water-washed, neutralized and dried through an integrated energy-saving preparation device; D. High temperature sintering: Silica is sintered at high temperature in a vacuum environment to further improve the purity of quartz sand. The sintered silica is crushed and screened to control the particle size and morphology to obtain ultra-high purity 7N grade synthetic quartz sand.

2. The process for preparing ultra-high purity 7N grade synthetic quartz sand according to claim 1, characterized in that: In step A, the volume ratio of tetraethoxysilane to ethanol is 1:3-1:5, and the volume ratio of ethanol to water is 1:1-1:

4.

3. The process for preparing ultra-high purity 7N grade synthetic quartz sand according to claim 1, characterized in that: The concentration of hydrochloric acid in step A is 0.1 mol / L~1 mol / L, and the amount of hydrochloric acid is 1-2 ml. Hydrochloric acid plays a catalytic role in the reaction, helps promote the hydrolysis reaction and controls the pH value of the sol, and the pH value of the sol is controlled between 4 and 5.

4. The process for preparing ultra-high purity 7N grade synthetic quartz sand according to claim 1, characterized in that: The hydrolysis reaction formula in step A is: Si(OC2H5)4 +4H2O→Si(OH)4+4C2H5OH, and the condensation reaction formula is Si(OH)4→Si-O-Si+H2O. As the reaction proceeds, the Si-O-Si bonds continue to increase, the viscosity of the solution gradually increases, and finally a gel network structure is formed.

5. The process for preparing ultra-high purity 7N grade synthetic quartz sand according to claim 1, characterized in that: The drying temperature in step B is 50-150° C. and the drying time is 12 to 24 hours.

6. The process for preparing ultra-high purity 7N grade synthetic quartz sand according to claim 1, characterized in that: The sintering temperature in step B is 1400-1600°C, and the sintering time is 3-6 hours.

7. The process for preparing ultra-high purity 7N grade synthetic quartz sand according to claim 1, characterized in that: The pickling solution used in step C is a mixed acid solution of concentrated nitric acid and concentrated hydrochloric acid, and the volume ratio of concentrated nitric acid:concentrated hydrochloric acid is 1:

3.

8. The process for preparing ultra-high purity 7N grade synthetic quartz sand according to claim 1, characterized in that: The neutralization solution used in step C is sodium hydroxide solution.

9. The process for preparing ultra-high purity 7N grade synthetic quartz sand according to claim 1, characterized in that: The calcination temperature in step D is 500-1000° C. and the calcination time is 4-48 hours.

10. The process for preparing ultra-high purity 7N grade synthetic quartz sand according to claim 1, characterized in that: An integrated energy-saving preparation device is used in steps A to C.

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