Preparation process of ultrahigh-purity spherical silicon dioxide

Abstract

The invention relates to a preparation process of ultra-high-purity spherical silicon dioxide, and belongs to the field of silicon dioxide preparation, and the preparation process comprises the following steps: S1, solution preparation: adding deionized water into a reaction kettle, starting a stirring device for stirring, slowly dropwise adding sodium silicate into the reaction kettle in the stirring process, and keeping the stirring speed uniform and stable in the dropwise adding process, fully mixing sodium silicate with deionized water to prepare a sodium silicate solution; the sodium polyacrylate is added into the reaction solution, so that a thick protection layer can be formed on the surfaces of the silicon dioxide particles, a steric hindrance effect is provided, particle aggregation is prevented, and uniform distribution of the particles is kept; the pH value of the solution can be adjusted by using the ammonia water, and the surface of the silicon dioxide particles can be helped to carry negative charges, so that the stability of the particles is improved, and aggregation among the particles is avoided; the sodium polyacrylate and the ammonia water have a synergistic effect, so that the uniformity and the stability of silicon dioxide particles are ensured, and the quality of a final product is further improved.

Description

Technical Field

[0001] The invention relates to a process for preparing ultra-high purity spherical silicon dioxide, and belongs to the field of silicon dioxide preparation. Background Art

[0002] With the rapid development of modern science and technology, ultra-high purity spherical silica has played an indispensable and key role in many cutting-edge fields. For example, in the field of optics, from high-end optical lenses, precision optical instruments to optical communication components, the optical uniformity, transmittance and low scattering properties of the material are crucial. Ordinary silica is difficult to meet these stringent requirements. Ultra-high purity spherical silica, due to its regular spherical structure, has extremely low scattering loss when light propagates in it, which can significantly improve the imaging clarity and optical signal transmission efficiency of optical components.

[0003] In the prior art, in order to improve the preparation purity of spherical silica, chemical methods are usually used for preparation. However, in the actual operation process of the existing spherical silica preparation process, ultra-high purity spherical silica is prepared by precisely controlling the reaction conditions and the purity of the raw materials. However, the process is relatively complicated, the cost is high, and the agglomeration phenomenon is serious, which cannot effectively improve the dispersibility of the spherical silica, thereby resulting in low efficiency and poor effect of subsequent washing and impurity removal, thereby reducing the preparation purity of the spherical silica and making it difficult to stably produce ultra-high purity spherical silica products that meet the strict requirements of various fields. Therefore, we have made improvements to this and proposed a process for preparing ultra-high purity spherical silica. Summary of the invention

[0004] (I) The technical problem to be solved by the present invention is that the existing spherical silica preparation process is relatively complicated and cannot effectively improve the dispersibility of spherical silica, resulting in serious agglomeration, which in turn leads to a decrease in the preparation purity of spherical silica.

[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 spherical silica, comprising the following steps: S1: Solution preparation: deionized water is added to the reaction kettle, and a stirring device is turned on for stirring. During the stirring process, sodium silicate is slowly added dropwise to the reaction kettle. During the dropping process, the stirring speed is kept uniform and stable, so that the sodium silicate and deionized water are fully mixed to obtain a sodium silicate solution; S2: Precipitation treatment: Add a surfactant to the sodium silicate solution, stir to fully disperse the surfactant in the sodium silicate solution, then slowly drop an acidifier into the sodium silicate solution, keep the stirring speed uniform and stable during the dropwise addition, at this time, the silicon dioxide in the solution begins to precipitate; S3: Spheroidization and dispersion treatment: Continue stirring the reaction solution, and add the viscosity modifier, stabilizer and dispersant into the solution. The silicon dioxide in the solution gradually precipitates and disperses to form fine particles that tend to be spherical. Then the reaction continues until the silicon dioxide particles are completely precipitated. S4: Post-treatment: After the precipitation is completed, the silica precipitate particles are filtered and separated from the reaction solution using a treatment device, and the silica precipitate particles are washed and subsequently dried; S5: Calcination treatment: The dried silica xerogel is placed in a high-temperature furnace for calcination to further densify the silica particles and improve the purity and sphericity of the product. The calcined product is ultra-high purity spherical silica.

[0006] Among them, the surfactant in S2 is sodium dodecylbenzene sulfonate, the acidulant in S2 is hydrochloric acid, the viscosity regulator in S3 is polyvinyl alcohol, the stabilizer in S3 is ammonia water, and the dispersant in S3 is sodium polyacrylate.

[0007] Among them, the molar ratio of sodium silicate: hydrochloric acid: deionized water: sodium dodecylbenzene sulfonate: polyvinyl alcohol: ammonia water: sodium polyacrylate is 1:2:20:0.05:0.1:1:0.05.

[0008] The reaction time from S1 to S3 is 2 to 6 hours, the temperature in the reactor in S1 is 30 to 60° C., and the rotation speed of the stirring device in S1 is 200 to 400 r / min.

[0009] Among them, the concentration of hydrochloric acid in S2 is 5%~8%, and the reaction equation of sodium silicate solution in S2 and hydrochloric acid is: Na2SiO3+2H2O+2HCl→SiO2 (precipitation)+2NaCl+2H2O.

[0010] After the silica particles in S3 are completely precipitated, stirring and heating are stopped, and the reaction system is allowed to stand and age at the original temperature for 3 to 6 hours.

[0011] Among them, the pH value of the reaction solution in S3 is controlled in the range of 3~5.

[0012] Wherein, the washing solution used in S4 is deionized water.

[0013] Among them, the calcination temperature in S5 is 500~1000℃, and the calcination time is 2~6 hours.

[0014] Among them, the processing equipment used in S4 is a high-efficiency processing device, including: A bottom plate, a positioning frame is welded and fixed on the top surface of the bottom plate, a collecting frame is slidably connected in the positioning frame, the bottom end surface of the collecting frame fits with the top surface of the bottom plate, a first hydraulic rod is installed and fixed on the top surface of the bottom plate, a first fixing plate is fixedly connected to the top of the first hydraulic rod, a device shell is welded and fixed on the first fixing plate, a high-efficiency stirring component is installed in the device shell, a high-efficiency drying component is installed in the device shell, a feed funnel is fixedly connected to the device shell, a magnetic cover plate is magnetically adsorbed and connected to the top of the feed funnel, a drain pipe is connected to the side end surface of the device shell, a solenoid valve is installed on the drain pipe, a support rod is welded and fixed on the inner bottom end surface of the collecting frame, and a sealing block is fixedly connected to the top of the support rod.

[0015] Among them, the outer wall of the device shell is in contact with the inner wall of the collection frame, the outer wall of the collection frame is in contact with the inner wall of the positioning frame, the first fixed plate is symmetrically distributed on both sides of the top of the device shell, the first fixed plate corresponds one-to-one to the first hydraulic rod, the drain pipes are symmetrically distributed on both sides of the device shell, and the support rod is fixed to the center of the bottom end surface inside the collection frame.

[0016] Among them, the high-efficiency stirring component includes a servo motor, which is welded and fixed on the top surface of the device shell, the output end of the servo motor is connected to the driving shaft, and the mounting frame is welded and fixed on the driving shaft. A guide groove is opened on the inner top of the mounting frame, and a guide block is slidingly connected in the guide groove. A driven shaft is rotatably connected to the guide block, and a flexible stirring rod is fixedly connected to the driven shaft.

[0017] Among them, the driving shaft is fixed at the center of the mounting frame, the mounting frame is rotatably connected in the device housing, the guide grooves are provided with four groups, each group of guide grooves is provided with two, the four groups of guide grooves are distributed at equal angles on the inner top of the mounting frame, the two guide grooves in each group are symmetrically distributed, the guide grooves correspond to the driven shaft one by one through the guide blocks, and the cross-section of the guide blocks is "T" shaped.

[0018] Among them, a circular gear is welded and fixed on the driven shaft, and a rack is meshed and connected on the circular gear. The driven shaft corresponds to the rack one by one through the circular gear, and the rack is welded and fixed to the inner wall of the mounting frame. A first connecting plate is rotatably connected to the driven shaft, and four first connecting plates are provided. Two adjacent driven shafts are rotatably connected to the same first connecting plate. A second connecting plate is welded and fixed on the first connecting plate, and the first connecting plate corresponds to the second connecting plate one by one. The second connecting plate is fixedly connected to the middle part of the first connecting plate, and the second connecting plate is A rotating shaft is fixedly connected, and a connecting rod is rotatably connected to the rotating shaft. Four connecting rods are provided, and both ends of the connecting rods are rotatably connected to adjacent rotating shafts respectively. A first filter plate is welded and fixed in the housing of the device, and the first filter plate is funnel-shaped. A first through groove is penetrated through the center of the first filter plate, and a conveying cylinder is welded and fixed in the first through groove. A fixing rod is welded and fixed on the top end surface of the conveying cylinder, and a push plate is welded and fixed on the top end of the fixing rod, and the push plate is shuttle-shaped. The bottom end of the drain pipe is flush with the bottom end surface of the first filter plate.

[0019] Among them, a second through groove is penetrated at the central part of the push plate, and the drive shaft is penetrated in the second through groove, the diameter of the drive shaft is smaller than the diameter of the second through groove, and a spiral rod is welded and fixed at the bottom end of the drive shaft, and the spiral rod is rotatably connected in the conveying cylinder, and a feed groove is provided on the conveying cylinder, and the feed grooves are symmetrically distributed on both sides of the conveying cylinder, and discharge pipes are connected on both sides of the top of the conveying cylinder, and the discharge pipes are inclined, and a scraper rod is welded and fixed on the bottom end surface of the mounting frame, and the scraper rods are distributed at equal angles on the bottom end surface of the mounting frame, and the side end surface of the scraper rod is in contact with the inner wall of the device housing, and the bottom end surface of the scraper rod is in contact with the top end surface of the first filter plate, the bottom end surface of the feed groove is flush with the end surface of the first filter plate, and the sealing block is in contact with the inner wall of the conveying cylinder.

[0020] Among them, the high-efficiency drying component includes an air duct, the top of the air duct is connected to the top side end of the device shell, the bottom of the air duct is connected to the bottom side end of the device shell, the air duct is symmetrically distributed on both sides of the device shell, the air pump is connected to the flange on the air duct, a second filter plate is welded and fixed on the top inner wall of the air duct, an electric heating tube is installed and fixed in the air duct, the electric heating tubes are equidistantly distributed in the air duct, the top side end face of the air duct and the side end face of the second filter plate are both in contact with the inner wall of the device shell, a transfer frame is welded and fixed in the device shell, and the side end of the transfer frame is connected to the bottom side end of the air duct.

[0021] Among them, a slide groove is opened through the bottom of the transfer frame, a diversion groove is opened through the top of the transfer frame, a sealing ring is fixedly connected in the diversion groove, the top end surface of the transfer frame is fitted with the bottom end surface of the first filter plate, a third through groove is opened through the middle part of the transfer frame, the inner wall of the third through groove is fitted with the outer wall of the conveying cylinder, a second fixed plate is welded and fixed on the inner wall of the device shell, a second hydraulic rod is installed and fixed on the top end surface of the second fixed plate, and a support plate is fixedly connected to the top end of the second hydraulic rod.

[0022] Among them, a sliding rod is welded and fixed on the top surface of the support plate, a baffle is welded and fixed on the top of the sliding rod, the sliding rod penetrates and is slidably connected in the slide groove, the diameter of the baffle is equal to the inner diameter of the sealing ring, the sliding rods are distributed at equal angles on the support plate, the sliding rods correspond one-to-one with the baffle and the slide groove respectively, and the baffle corresponds one-to-one with the diversion groove through the sealing ring.

[0023] Beneficial Effects The invention provides a process for preparing ultra-high purity spherical silicon dioxide, which has the following beneficial effects: 1. By adding sodium polyacrylate to the reaction solution, a thick protective layer can be formed on the surface of the silica particles, providing a steric hindrance effect, preventing the particles from aggregating, and maintaining the uniform distribution of the particles; and ammonia water can be used to adjust the pH value of the solution and maintain a proper alkaline environment, which is essential for the precipitation reaction of silicates. It can also help the surface of the silica particles to carry a negative charge, thereby improving the stability of the particles, while avoiding aggregation between particles, and further improving the sphericity and dispersibility; sodium polyacrylate and ammonia water work synergistically to ensure the uniformity and stability of the silica particles, thereby improving the quality of the final product.

[0024] 2. By adding sodium dodecylbenzene sulfonate to the sodium silicate solution, the surface properties of the silica particles can be improved, the particles can be prevented from agglomerating, and the sphericity and dispersibility of the silica particles can be further improved; and by adding polyvinyl alcohol, the viscosity of the solution can be increased, the movement of the precipitate particles can be slowed down, and the uniform growth of the particles can be promoted; and after the silica particles are completely precipitated, the silica particles can be further grown and improved by static aging, and the sphericity and crystallinity of the silica particles can be further improved. The process is simple and the preparation cost is not high; and by avoiding the agglomeration of the silica particles, the efficiency and thoroughness of the subsequent washing and impurity removal of the silica particles can be effectively improved, thereby effectively improving the preparation purity of the spherical silica.

[0025] 3. Driven by the servo motor, the driving shaft can drive the installation frame and the spiral rod to rotate at the same time. At this time, the installation frame can drive each driven shaft to perform circular motion, and the push plate can push each driven shaft to perform automatic and stable lateral reciprocating motion during the circular motion. At the same time, under the meshing drive of the circular gear and the rack, each driven shaft can also automatically reciprocate during the circular motion and lateral reciprocating motion. Combined with each flexible stirring rod, the silicon dioxide particles can be fully and evenly contacted with the deionized water washing solution, thereby achieving efficient washing of silicon dioxide, effectively improving the washing efficiency and washing effect of silicon dioxide, and avoiding incomplete washing affecting the purity and quality of silicon dioxide; at the same time, under the continuous rotation of the spiral rod, the silicon dioxide in the lower layer can be continuously transported to the upper layer, avoiding the accumulation of silicon dioxide, resulting in the problem that silicon dioxide cannot be fully and evenly contacted with the washing solution, and further improving the washing efficiency and washing effect of silicon dioxide.

[0026] 4. The air duct and air pump are provided to realize the circulation of air inside the device, and the air circulating inside the device can be heated by the electric heating tube to avoid heat loss; at the same time, combined with the efficient stirring component for efficient stirring of silica, lower-layer transportation and continuous upward transportation of air, the washed silica can be subjected to comprehensive and efficient decentralized drying treatment, realizing integrated filtering, washing and drying treatment of silica, further improving the treatment efficiency, and increasing the diversity and efficiency of the treatment device.

[0027] 5. By driving the first hydraulic rod, the device housing can be lifted upward and separated from the collection frame. At the same time, the sealing block can automatically separate from the conveying cylinder. Then, by the reverse rotation of the spiral rod, the treated silicon dioxide can be automatically unloaded and collected, ensuring the convenience of subsequent transportation and processing of silicon dioxide. 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 of the present invention; Figure 2 This is a schematic diagram of the connection structure between the feed hopper and the magnetic cover plate of the present invention; Figure 3 It is a schematic diagram of the connection structure between the first hydraulic rod and the first fixing plate of the present invention; Figure 4 This is a schematic diagram of the connection structure between the drive shaft and the mounting frame of the present invention; Figure 5 It is a schematic diagram of the connecting structure of the guide groove and the guide block of the present invention; Figure 6 This is a schematic diagram of the connection structure of a circular gear and a rack according to the present invention; Figure 7 It is a schematic diagram of the connection structure between the conveying cylinder and the feeding trough of the present invention; Figure 8 This is a schematic diagram of the connection structure between the support rod and the sealing block of the present invention; Fig. 9 This is a schematic diagram of the main cross-section connection structure of the conveying tube of the present invention; Fig.10 For the present invention Figure 4 The enlarged structural diagram at A in the middle; Fig.11 It is a schematic diagram of the connection structure between the support plate and the slide rod of the present invention; Fig.12 This is a schematic diagram of the connection structure between the sealing ring and the second fixing plate of the present invention; Fig.13 It is a schematic diagram of the connection structure between the second hydraulic rod and the support plate of the present invention; Fig.14 It is a schematic diagram of the main cross-sectional structure of the airway of the present invention.

[0030] In the figure: 1, bottom plate; 2, positioning frame; 3, collecting frame; 4, first hydraulic rod; 5, first fixed plate; 6, device housing; 7, high-efficiency stirring assembly; 701, servo motor; 702, driving shaft; 703, mounting frame; 704, guide groove; 705, guide block; 706, driven shaft; 707, flexible stirring rod; 708, circular gear; 709, rack; 710, first connecting plate; 711, second connecting plate; 712, rotating shaft; 713, connecting rod; 714, first filter plate; 715, first through groove; 716, conveying cylinder; 717, fixing rod; 718, Push plate; 719, second through slot; 720, spiral rod; 721, feed slot; 722, discharge pipe; 723, scraper rod; 8, high-efficiency drying component; 801, air guide pipe; 802, air pump; 803, second filter plate; 804, electric heating tube; 805, transfer frame; 806, slide slot; 807, diversion slot; 808, sealing ring; 809, second fixed plate; 810, second hydraulic rod; 811, support plate; 812, slide rod; 813, baffle; 814, third through slot; 9, feed hopper; 10, magnetic cover plate; 11, discharge pipe; 12, support rod; 13, sealing block. 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 and Fig.14 As shown, this embodiment provides a process for preparing ultra-high purity spherical silicon dioxide, comprising the following steps: S1: Solution preparation: deionized water is added to the reactor, and the stirring device is turned on for stirring. During the stirring process, sodium silicate is slowly added dropwise to the reactor. During the dropping process, the stirring speed is kept uniform and stable, so that the sodium silicate and deionized water are fully mixed to obtain a sodium silicate solution; the temperature in the reactor is 30-60°C, and the speed of the stirring device is 200-400r / min; S2: Precipitation treatment: Add sodium dodecylbenzene sulfonate to the sodium silicate solution, stir to fully disperse the surfactant in the sodium silicate solution, then slowly drop hydrochloric acid into the sodium silicate solution, keep the stirring speed uniform and stable during the dropwise addition, and the silicon dioxide in the solution begins to precipitate; the concentration of hydrochloric acid is 5%~8%, and the reaction equation of sodium silicate solution and hydrochloric acid is: Na2SiO3+2H2O+2HCl→SiO2 (precipitation)+2NaCl+2H2O; S3: Spheroidization and dispersion treatment: Continue to stir the reaction solution, and add polyvinyl alcohol, ammonia water and sodium polyacrylate into the solution, the silicon dioxide in the solution gradually precipitates and disperses to form fine particles, and tends to be spherical, and then the reaction continues until the silicon dioxide particles are completely precipitated; wherein, the molar ratio of sodium silicate: hydrochloric acid: deionized water: sodium dodecylbenzene sulfonate: polyvinyl alcohol: ammonia water: sodium polyacrylate is 1:2:20:0.05:0.1:1:0.05; the pH value of the reaction solution is controlled in the range of 3 to 5; After the silica particles are completely precipitated, stop stirring and heating, and let the reaction system stand at the original temperature for 3 to 6 hours; S4: Post-treatment: After precipitation, the silica precipitate particles are filtered and separated from the reaction solution using a treatment device, and the silica precipitate particles are washed with deionized water and subsequently dried; S5: Calcination treatment: The dried silica xerogel is placed in a high-temperature furnace for calcination at a temperature of 500-1000°C for 2-6 hours to further densify the silica particles and improve the purity and sphericity of the product. The calcined product is ultra-high purity spherical silica.

[0033] The processing equipment used in S4 is a high-efficiency processing device, including: A bottom plate 1 is welded and fixed with a positioning frame 2 on the top surface of the bottom plate 1, a collecting frame 3 is slidably connected in the positioning frame 2, the bottom end surface of the collecting frame 3 fits with the top surface of the bottom plate 1, a first hydraulic rod 4 is fixedly installed on the top surface of the bottom plate 1, a first fixing plate 5 is fixedly connected to the top of the first hydraulic rod 4, a device housing 6 is welded and fixed on the first fixing plate 5, a high-efficiency stirring component 7 is installed in the device housing 6, a high-efficiency drying component 8 is installed in the device housing 6, a feed funnel 9 is fixedly connected to the device housing 6, a magnetic cover plate 10 is magnetically adsorbed and connected to the top of the feed funnel 9, a drain pipe 11 is connected to the side end surface of the device housing 6, and a solenoid valve is installed on the drain pipe 11 A support rod 12 is welded and fixed on the inner bottom end surface of the collecting frame 3, and a sealing block 13 is fixedly connected to the top of the support rod 12. The silicon dioxide particles and the deionized water washing liquid can be fully and evenly stirred through the high-efficiency stirring component 7, thereby realizing the efficient washing of silicon dioxide, effectively improving the washing efficiency and washing effect of silicon dioxide, and avoiding the influence of incomplete washing on the purity and quality of silicon dioxide; and in conjunction with the high-efficiency drying component 8, the washed silicon dioxide can be subjected to a comprehensive and efficient decentralized drying treatment, thereby realizing the integrated filtering, washing and drying treatment of silicon dioxide, further improving the treatment efficiency, and increasing the diversity and efficiency of the treatment device.

[0034] Embodiment 2: The solution in Example 1 is further introduced below in combination with a specific working method, as described below: like Figure 4 , Figure 5 and Figure 6As shown, as a preferred embodiment, on the basis of the above-mentioned method, further, the high-efficiency stirring component 7 includes a servo motor 701, the servo motor 701 is welded and fixed on the top surface of the device housing 6, the output end of the servo motor 701 is connected to a driving shaft 702, and a mounting frame 703 is welded and fixed on the driving shaft 702. A guide groove 704 is provided at the top of the inner top of the mounting frame 703, and a guide block 705 is slidingly connected in the guide groove 704. A driven shaft 706 is rotatably connected to the guide block 705, and a flexible stirring rod 707 is fixedly connected to the driven shaft 706. The driving shaft 702 is fixed to the mounting frame 70 3, the mounting frame 703 is rotatably connected in the device housing 6, four groups of guide grooves 704 are provided, each group of guide grooves 704 is provided with two, and the four groups of guide grooves 704 are distributed at equal angles on the inner top of the mounting frame 703, and the two guide grooves 704 in each group are symmetrically distributed, and the guide grooves 704 correspond to the driven shaft 706 one by one through the guide blocks 705, and the cross section of the guide blocks 705 is "T"-shaped. Under the limiting guiding action of the guide blocks 705 and the guide grooves 704, the stability of the motion state of the high-efficiency stirring assembly 7 can be ensured through the driven shaft 706, thereby ensuring the stability and safety of the subsequent stirring work.

[0035] like Figure 6 , Figure 7 and Figure 8As shown, as a preferred embodiment, on the basis of the above-mentioned method, further, a circular gear 708 is welded and fixed on the driven shaft 706, and a rack 709 is meshed and connected on the circular gear 708. The driven shaft 706 corresponds to the rack 709 one by one through the circular gear 708, and the rack 709 is welded and fixed on the inner wall of the mounting frame 703. The driven shaft 706 is rotatably connected to a first connecting plate 710, and four first connecting plates 710 are provided. Two adjacent driven shafts 706 are rotatably connected to the same first connecting plate 710. 0, a second connecting plate 711 is welded and fixed on the first connecting plate 710, the first connecting plate 710 corresponds to the second connecting plate 711 one by one, the second connecting plate 711 is fixedly connected to the middle part of the first connecting plate 710, a rotating shaft 712 is fixedly connected to the second connecting plate 711, a connecting rod 713 is rotatably connected to the rotating shaft 712, four connecting rods 713 are provided, and both ends of the connecting rod 713 are rotatably connected to adjacent rotating shafts 712, a first filter plate 714 is welded and fixed in the device housing 6, The first filter plate 714 is funnel-shaped, and a first through slot 715 is provided in the center of the first filter plate 714. A conveying cylinder 716 is welded and fixed in the first through slot 715. A fixing rod 717 is welded and fixed on the top surface of the conveying cylinder 716. A push plate 718 is welded and fixed on the top of the fixing rod 717. The push plate 718 is shuttle-shaped, and the bottom end of the drain pipe 11 is flush with the bottom end surface of the first filter plate 714. The driving shaft 702 can drive the installation frame 703 and the spiral rod 720 to rotate at the same time. At this time, the installation frame 703 can It can drive each driven shaft 706 to perform circular motion, and cooperate with the push plate 718 to push each driven shaft 706 to perform automatic and stable lateral reciprocating motion during the circular motion. At the same time, under the meshing drive of the circular gear 708 and the rack 709, each driven shaft 706 can also automatically reciprocate during the circular motion and lateral reciprocating motion. Combined with each flexible stirring rod 707, the silicon dioxide particles can be fully and evenly contacted with the deionized water washing liquid, thereby achieving efficient washing of silicon dioxide.

[0036] like Figure 6 , Figure 7 , Figure 8 and Fig. 9As shown, as a preferred embodiment, on the basis of the above-mentioned method, further, a second through slot 719 is formed through the center of the push plate 718, the drive shaft 702 is arranged in the second through slot 719, the diameter of the drive shaft 702 is smaller than the diameter of the second through slot 719, a screw rod 720 is welded and fixed to the bottom end of the drive shaft 702, the screw rod 720 is rotatably connected in the conveying cylinder 716, a feed slot 721 is formed on the conveying cylinder 716, the feed slots 721 are symmetrically distributed on both sides of the conveying cylinder 716, discharge pipes 722 are connected to both sides of the top of the conveying cylinder 716, the discharge pipes 722 are inclined, and a scraper rod 723 is welded and fixed to the bottom end surface of the mounting frame 703. The scraper rod 723 is distributed at equal angles on the bottom surface of the mounting frame 703, the side surface of the scraper rod 723 is in contact with the inner wall of the device housing 6, the bottom surface of the scraper rod 723 is in contact with the top surface of the first filter plate 714, the bottom surface of the feed trough 721 is flush with the end surface of the first filter plate 714, the sealing block 13 is in contact with the inner wall of the conveying cylinder 716, and during the operation of the driving shaft 702, the screw rod 720 can be driven to rotate synchronously. Under the continuous rotation of the screw rod 720, the silicon dioxide in the lower layer can be continuously conveyed to the upper layer, thereby avoiding the accumulation of silicon dioxide, resulting in the problem that the silicon dioxide cannot be fully and evenly contacted with the washing solution, and further improving the washing efficiency and washing effect of the silicon dioxide.

[0037] like Figure 2 , Figure 3 and Figure 4 As shown, as a preferred embodiment, on the basis of the above method, further, the outer wall of the device shell 6 is in contact with the inner wall of the collecting frame 3, the outer wall of the collecting frame 3 is in contact with the inner wall of the positioning frame 2, the first fixed plate 5 is symmetrically distributed on both sides of the top of the device shell 6, the first fixed plate 5 corresponds to the first hydraulic rod 4 one by one, the discharge pipe 11 is symmetrically distributed on both sides of the device shell 6, the support rod 12 is fixed to the central part of the bottom end surface inside the collecting frame 3, and the device shell 6 can be lifted up and separated from the collecting frame 3 by driving the first hydraulic rod 4. At the same time, the sealing block 13 can automatically separate from the conveying cylinder 716, and then the reverse rotation of the screw rod 720 can be used to automatically unload and collect the treated silicon dioxide, thereby ensuring the convenience of subsequent transportation and processing of the silicon dioxide.

[0038] like Figure 2 , Figure 3 , Figure 4 and Fig.14As shown, as a preferred embodiment, on the basis of the above-mentioned method, further, the high-efficiency drying component 8 includes an air duct 801, the top of the air duct 801 is connected to the top side end of the device housing 6, the bottom of the air duct 801 is connected to the bottom side end of the device housing 6, the air duct 801 is symmetrically distributed on both sides of the device housing 6, the air duct 801 is flange-connected to an air pump 802, a second filter plate 803 is welded and fixed on the top inner wall of the air duct 801, and an electric heating tube 804 is installed and fixed in the air duct 801 The electric heating tubes 804 are evenly distributed in the air duct 801. The top side end surface of the air duct 801 and the side end surface of the second filter plate 803 are both in contact with the inner wall of the device shell 6. A transfer frame 805 is welded and fixed in the device shell 6. The side end of the transfer frame 805 is connected to the bottom side end of the air duct 801. The air circulation inside the device is realized by the arranged air duct 801 and the air pump 802, and the air circulating inside the device can be heated by the electric heating tube 804 to avoid heat loss.

[0039] like Figure 4 , Fig.10 , Fig.11 , Fig.12 and Fig.13 As shown, as a preferred embodiment, on the basis of the above-mentioned method, further, a slide groove 806 is provided through the bottom of the transfer frame 805, a diversion groove 807 is provided through the top of the transfer frame 805, a sealing ring 808 is fixedly connected in the diversion groove 807, the top end surface of the transfer frame 805 is fitted with the bottom end surface of the first filter plate 714, a third through groove 814 is provided through the middle of the transfer frame 805, the inner wall of the third through groove 814 is fitted with the outer wall of the conveying cylinder 716, a second fixing plate 809 is welded and fixed on the inner wall of the device housing 6, a second hydraulic rod 810 is installed and fixed on the top surface of the second fixing plate 809, a support plate 811 is fixedly connected to the top end of the second hydraulic rod 810, and the support plate 81 1 is welded and fixed with a slide bar 812, and a baffle plate 813 is welded and fixed with the top end of the slide bar 812. The slide bar 812 penetrates and slides in the slide groove 806. The diameter of the baffle plate 813 is equal to the inner diameter of the sealing ring 808. The slide bars 812 are distributed at equal angles on the support plate 811. The slide bars 812 correspond to the baffle plates 813 and the slide groove 806 one by one, respectively. The baffle plates 813 correspond to the diverter groove 807 one by one through the sealing ring 808. Combined with the efficient stirring component 7 for efficient stirring of silicon dioxide, lower layer transportation and continuous upward transportation of air, the washed silicon dioxide can be subjected to comprehensive and efficient decentralized drying treatment, realizing integrated filtering, washing and drying treatment of silicon dioxide, and further improving the treatment efficiency.

[0040] 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 high-efficiency processing device for the preparation process of ultra-high purity spherical silica is in use: first, the staff can lift the magnetic cover plate 10 on the feed funnel 9, and then the reacted silica and reaction solution can be transported to the device housing 6. At this time, under the filtering action of the first filter plate 714, the silica and reaction solution can be filtered, and the filtered reaction solution can be discharged by opening the solenoid valve on the drain pipe 11. After discharge, the solenoid valve can be closed, and then the deionized water for washing is transported to the device housing 6 through the feed funnel 9, and the servo motor 701 is driven.

[0041] Under the driving action of the servo motor 701, the driving shaft 702 can drive the installation frame 703 to rotate stably in the device housing 6, and then the guide blocks 705 in the guide grooves 704 can drive the corresponding driven shafts 706 to perform stable circular motion. At the same time, the installation frame 703 can drive each first connecting plate 710 and the corresponding second connecting plate 711 to perform synchronous circular motion through the driven shaft 706. Since the push plate 718 is in a fixed state and the push plate 718 is shuttle-shaped as a whole, when the first connecting plate 710 and the second connecting plate 7 When 11 moves to the protrusions at both ends of the push plate 718, the first connecting plate 710 and the second connecting plate 711 at the protrusions at both ends of the push plate 718 are pushed to the inner side of the installation frame 703; under the limiting and guiding action of the guide block 705 and the guide groove 704, the stability of the movement state of the first connecting plate 710 can be ensured by the driven shaft 706; at the same time, under the connection action of each rotating shaft 712 and the corresponding connecting rod 713, the first connecting plate 710 and the second connecting plate 711 that are not pushed are pulled to move toward the middle part of the installation frame 703.

[0042] In this way, the installation frame 703 drives each driven shaft 706 to perform circular motion. Under the guiding and pushing action of the push plate 718, combined with the connecting rod 713 on each rotating shaft 712, it can drive the driven shaft 706 on each first connecting plate 710 to perform automatic and stable horizontal reciprocating motion. During the reciprocating motion of the driven shaft 706, the driven shaft 706 can drive the circular gear 708 to reciprocate on the rack 709. Therefore, under the meshing driving action of the circular gear 708 and the rack 709, each driven shaft 706 can also automatically reciprocate during the circular motion and lateral reciprocating motion, thereby being able to fully and evenly stir the silica particles and the deionized water washing liquid at various locations inside the device, ensuring that the silica particles are in full and even contact with the deionized water washing liquid, thereby achieving efficient silica washing.

[0043] At the same time, during the operation, the driving shaft 702 can drive the spiral rod 720 to rotate stably in the conveying cylinder 716. Under the continuous rotation of the spiral rod 720, the silicon dioxide and deionized water of the lower layer can be spirally conveyed through the feed trough 721, and the silicon dioxide and deionized water of the lower layer can be conveyed to the upper layer through the discharge pipe 722, and so on, thereby further improving the washing efficiency and washing effect of the silicon dioxide.

[0044] After the washing work is completed, the solenoid valve on the drain pipe 11 can be opened again to discharge the waste liquid. After the discharge work is completed, the solenoid valve can be closed and the second hydraulic rod 810 on the second fixed plate 809 can be driven. At this time, the second hydraulic rod 810 can drive the support plate 811 to move downward, and then drive the baffles 813 on each slide bar 812 to move downward. At this time, the baffle 813 moves away from the diverter groove 807 and the sealing ring 808, and the baffle 813 moves downward to close the slide groove 806; at this time, by driving the air pump 802 on the air guide tubes 801 on both sides, the top of the air guide tube 801 sucks the air inside the device shell 6 and transports it to the transfer frame 805, and then the air in the transfer frame 805 is transported to the first The air circulates through the filter plate 714 and is transported to the device housing 6 through the first filter plate 714, thereby realizing the circulation of air inside the device, and the air circulating inside the device can be heated by the electric heating tube 804 to avoid heat loss; at the same time, combined with the efficient stirring component 7 for efficient stirring of silicon dioxide, the upward transportation of the lower layer and the continuous upward transportation of air, the washed silicon dioxide can be subjected to comprehensive and efficient decentralized drying treatment. After the drying treatment is completed, the second hydraulic rod 810 can be driven to drive the support plate 811 to move upward and reset, and then the baffle 813 can be driven to move upward and reset through the sliding rod 812, and the diverter slot 807 can be closed in combination with the sealing ring 808 to ensure the stability of the subsequent filtering work of the first filter plate 714.

[0045] After the drying process is completed, the first hydraulic rod 4 on the bottom plate 1 can be driven to lift the device housing 6 upward and separate from the collection frame 3 through the first fixed plate 5. At the same time, the conveying cylinder 716 inside the device housing 6 moves upward synchronously and moves away from the sealing block 13. At this time, the drive shaft 702 is driven by the servo motor 701 to rotate in the opposite direction, and then the installation frame 703 and the screw rod 720 can be driven to rotate in the opposite direction. Under the reverse rotation of the screw rod 720, the spiral feeding direction is downward. At this time, the silicon dioxide in the device can enter the conveying cylinder 716 through the feeding trough 721 and be transported downward to the collection frame 3. In addition, during the rotation of the installation frame 703, each scraper rod 723 can be driven to move stably, so that the first filter plate 714 and the silicon dioxide in the device can be pushed into the conveying cylinder 716, completing the automatic unloading and collection of silicon dioxide, and ensuring the convenience of subsequent transportation and processing of silicon dioxide.

[0046] 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 spherical silicon dioxide, characterized in that: The following steps are involved: S1: Solution preparation: deionized water is added to the reaction kettle, and a stirring device is turned on for stirring. During the stirring process, sodium silicate is slowly added dropwise to the reaction kettle. During the dropping process, the stirring speed is kept uniform and stable, so that the sodium silicate and deionized water are fully mixed to obtain a sodium silicate solution; S2: Precipitation treatment: Add a surfactant to the sodium silicate solution, stir to fully disperse the surfactant in the sodium silicate solution, then slowly drop an acidifier into the sodium silicate solution, keep the stirring speed uniform and stable during the dropwise addition, at this time, the silicon dioxide in the solution begins to precipitate; S3: Spheroidization and dispersion treatment: Continue stirring the reaction solution, and add the viscosity modifier, stabilizer and dispersant into the solution. The silicon dioxide in the solution gradually precipitates and disperses to form fine particles that tend to be spherical. Then the reaction continues until the silicon dioxide particles are completely precipitated. S4: Post-treatment: After the precipitation is completed, the silica precipitate particles are filtered and separated from the reaction solution using a treatment device, and the silica precipitate particles are washed and subsequently dried; S5: Calcination treatment: The dried silica xerogel is placed in a high-temperature furnace for calcination to further densify the silica particles and improve the purity and sphericity of the product. The calcined product is ultra-high purity spherical silica.

2. A process for preparing ultra-high purity spherical silicon dioxide according to claim 1, characterized in that: The surfactant in S2 is sodium dodecylbenzene sulfonate, the acidulant in S2 is hydrochloric acid, the viscosity regulator in S3 is polyvinyl alcohol, the stabilizer in S3 is ammonia water, and the dispersant in S3 is sodium polyacrylate.

3. A process for preparing ultra-high purity spherical silicon dioxide according to claim 2, characterized in that: The molar ratio of sodium silicate: hydrochloric acid: deionized water: sodium dodecylbenzene sulfonate: polyvinyl alcohol: ammonia water: sodium polyacrylate is 1:2:20:0.05:0.1:1:0.

05.

4. A process for preparing ultra-high purity spherical silicon dioxide according to claim 1, characterized in that: The reaction time from S1 to S3 is 2 to 6 hours, the temperature in the reactor in S1 is 30 to 60° C., and the rotation speed of the stirring device in S1 is 200 to 400 r / min.

5. A process for preparing ultra-high purity spherical silicon dioxide according to claim 3, characterized in that: The concentration of hydrochloric acid in S2 is 5%~8%, and the reaction equation of sodium silicate solution in S2 and hydrochloric acid is: Na2SiO3+2H2O+2HCl→SiO2 (precipitation)+2NaCl+2H2O.

6. A process for preparing ultra-high purity spherical silicon dioxide according to claim 1, characterized in that: After the silicon dioxide particles in S3 are completely precipitated, stirring and heating are stopped, and the reaction system is allowed to stand and age at the original temperature for 3 to 6 hours.

7. A process for preparing ultra-high purity spherical silicon dioxide according to claim 1, characterized in that: The pH value of the reaction solution in S3 is controlled in the range of 3 to 5.

8. A process for preparing ultra-high purity spherical silicon dioxide according to claim 1, characterized in that: The washing solution used in S4 is deionized water.

9. A process for preparing ultra-high purity spherical silicon dioxide according to claim 1, characterized in that: The calcination temperature in S5 is 500-1000° C., and the calcination time is 2-6 hours.

10. A process for preparing ultra-high purity spherical silicon dioxide according to claim 1, characterized in that: The processing equipment used in S4 is a high-efficiency processing device.

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