A purification detection system and a production process of 6N ultra-high purity calcium fluoride for artificial lenses

Abstract

The present invention relates to the technical field of ultra-high purity calcium fluoride, and in particular to a purification detection system and a production process of 6N ultra-high purity calcium fluoride for artificial lenses. The control core of the purification detection system is a hollow structure, and the side wall of the control core is provided with a liquid outlet connected to its internal space. The inner diameter of the collecting sleeve is adapted to the outer diameter of the control core, and the inner wall of the collecting sleeve is provided with a collecting groove, which continuously extends into a ring shape along the circumference of the collecting sleeve. The outer wall of the control core is threadedly matched with the inner wall of the collecting sleeve, and the control core and the collecting sleeve are rotatably sealed. When the liquid outlet is connected to the collecting groove, the circulating liquid enters the collecting groove through the liquid outlet. When the liquid outlet is just connected to a collecting groove, the end of the control core does not close the collecting groove. When the liquid outlet is just disconnected from a collecting groove, the end of the control core just closes the collecting groove. It can help technicians to realize rapid detection and analysis of the purification process, so as to more accurately grasp the actual progress of purification.

Description

Technical Field

[0001] The present invention relates to the technical field of ultra-high purity calcium fluoride, and in particular to a purification detection system and a production process of 6N ultra-high purity calcium fluoride for artificial lenses. Background Art

[0002] Calcium fluoride is a very important optical functional crystal with good optical properties, mechanical properties and physical and chemical stability. It can be used as optical crystals, laser crystals and inorganic scintillating crystals. Calcium fluoride has excellent comprehensive properties such as wide light transmission range (from far ultraviolet to mid-infrared), high transmittance, low refractive index, small absorption coefficient, strong resistance to chemical corrosion and high laser damage threshold. Calcium fluoride crystals are now most widely used in optics. From the vacuum ultraviolet band to the mid-infrared band, they are widely used as materials such as windows, lenses, prisms, beam splitters, substrates, filters and polarizing elements, and phase compensation mirrors in optical instruments. They are widely used in the emission, processing and reception of light in optical circuits.

[0003] In the actual application of calcium fluoride, the purity of calcium fluoride is very important. Therefore, technicians have been committed to preparing calcium fluoride products with higher purity. How to more accurately evaluate and optimize the purification process of calcium fluoride can help further improve the purity of calcium fluoride products.

[0004] In the purification production of calcium fluoride, especially in the batch production process, how to more accurately and comprehensively monitor and optimize the purification process of calcium fluoride is actually very difficult to implement. For example, it is difficult to continuously follow up and analyze the purification reaction of calcium fluoride (or the residual situation of impurity ions), which makes it difficult to fully grasp the real-time progress of the purification step, which is not conducive to optimizing the time period with lower efficiency in a step.

[0005] In view of this, this application is hereby filed. Summary of the invention

[0006] The first purpose of the present invention is to provide a purification detection system, which can help technicians to quickly detect and analyze the purification process, so as to more accurately grasp the actual progress of purification. It has positive significance for streamlining the purification process and eliminating inefficient links, and can help promote high-efficiency, low-cost, and high-purity reforms in purification technology.

[0007] The second object of the present invention is to provide a 6N ultra-high purity calcium fluoride production process for artificial lenses, which can achieve high purification of calcium fluoride and simultaneously realize accurate monitoring of the purification process, thereby improving the purification efficiency and ensuring the purification quality.

[0008] The embodiment of the present invention is achieved as follows:

[0009] A purification detection system comprises a control core and a collection sleeve.

[0010] The control core is a hollow structure, and a liquid outlet connected to its internal space is provided on the side wall of the control core. The liquid outlet is arranged near one end of the control core, and the other end of the control core is used to connect to the circulation pipeline of the purification reaction container.

[0011] The inner diameter of the collecting sleeve is matched with the outer diameter of the control core, and the inner wall of the collecting sleeve is provided with a collecting groove, which continuously extends into a ring shape along the circumference of the collecting sleeve. Along the axial direction of the collecting sleeve, a plurality of collecting grooves are sequentially arranged at intervals.

[0012] The outer wall of the control core is threadedly matched with the inner wall of the collecting sleeve, and a rotation seal is formed between the control core and the collecting sleeve. The control core is driven by a driving component.

[0013] The collecting sleeve is used to be installed in the purification reaction container. During the circulation process, the circulating liquid enters the control core through the circulation pipeline.

[0014] When the liquid outlet is connected to the collecting tank, the circulating liquid enters the collecting tank through the liquid outlet. When the liquid outlet is just connected to a collecting tank, the end of the control core does not close the collecting tank. When the liquid outlet is just disconnected from a collecting tank, the end of the control core just closes the collecting tank.

[0015] Furthermore, the purification detection system also includes: an analysis end.

[0016] The collecting sleeve is connected to the analysis end through a delivery pipe, the delivery pipe is communicated with the collecting tank, and each collecting tank is correspondingly provided with a delivery pipe for delivering the circulating liquid in the collecting tank to the analysis end separately.

[0017] Furthermore, the purification detection system also includes: a controller.

[0018] The controller is used to determine the rotation speed of the driving component to drive the control core according to the set cycle time, so that during the cycle time, the control core can gradually enter the collection sleeve and the control core can just move from one end of the collection sleeve to the other end of the collection sleeve.

[0019] Furthermore, a matching pipe is provided at one end of the control core for communicating with the circulation pipeline, the matching pipe is communicated with the inner space of the control core, the matching pipe and the control core are coaxially arranged, the matching pipe can be rotatably matched with the control core and is rotationally sealed with the control core. The control core is communicated with the circulation pipeline through the matching pipe.

[0020] Furthermore, the end surface of the control core at one end where the liquid outlet is provided has a protrusion, the protrusion is arranged close to the edge of the control core, and the side wall of the protrusion is in contact with the inner wall of the collection sleeve. The internal space of the collection sleeve extends to the protrusion, and the liquid outlet is provided on one side of the protrusion for contacting with the inner wall of the collection sleeve.

[0021] Furthermore, the protruding portion and the end of the control core together form an oblique truncated cylindrical structure.

[0022] The control core is also provided with a one-way valve, which is arranged on the inclined end surface of the oblique cylindrical structure. The inlet end of the one-way valve is communicated with the internal space of the control core, and the outlet end of the one-way valve is communicated with the collecting sleeve.

[0023] Wherein, along the axial direction of the control core, the maximum protruding portion of the protruding portion extends beyond the exposed portion of the one-way valve.

[0024] The above purification and detection system is used in the production of 6N ultra-high purity calcium fluoride for artificial lenses.

[0025] A production process of 6N ultra-high purity calcium fluoride for artificial lenses comprises: when performing purification operation on a liquid phase system, the collection sleeve of the purification detection system is fixedly installed in a reaction kettle, and the circulation pipeline of the reaction kettle is connected to the control core of the purification detection system.

[0026] According to the set purification time, the speed of the driving component driving the control core is determined so that within the purification time, the control core can gradually enter the collection sleeve and move from one end of the collection sleeve to the other end of the collection sleeve.

[0027] Furthermore, the production process of 6N ultra-high purity calcium fluoride for artificial lens includes the following steps:

[0028] S1. React nitric acid and calcium sand, add ammonia water to adjust the pH value to 5-6, and then settle for 24 hours.

[0029] S2. Add calcium hydroxide to the supernatant after sedimentation in S1, adjust the pH value to 10-11, stop stirring after stirring and circulating, let settle for 48 hours, and take the supernatant. During the stirring and circulating process, the collection sleeve of the above-mentioned purification and detection system is fixedly installed in the reactor of S2, and the circulation pipeline of the reactor of S2 is connected to the control core of the purification and detection system. According to the set stirring cycle time, determine the speed of the driving component to drive the control core, so that within the stirring cycle time, the control core can gradually enter the collection sleeve, and the control core can just move from one end of the collection sleeve to the other end of the collection sleeve.

[0030] S3, adding an extractant to the supernatant of S2, stirring, standing and separating the extractant. The extractant includes: any one of di(2-ethylhexyl)phosphoric acid, bis(2,4,4-trimethylpentyl)phosphonic acid, diisooctyl oxalate and cyclohexane acid.

[0031] S4. Add potassium hydroxide to the system separated in S3, separate the precipitate from the supernatant, and obtain calcium hydroxide precipitate.

[0032] S5. Wash the calcium hydroxide precipitate with pure water.

[0033] S6. Reacting nitric acid with the washed calcium hydroxide precipitate to obtain a calcium nitrate solution.

[0034] S7. Utilize hydrofluoric acid and calcium nitrate solution to react calcium fluoride, stop stirring after the reaction, remove the supernatant after sedimentation, add nitric acid to stir and wash the sedimentation part, filter the sedimentation part to obtain a precipitate, wash the precipitate with pure water until the pH value of the washing liquid is 6-7, and obtain calcium fluoride slurry.

[0035] S8. Dehydrate the calcium fluoride slurry at 80-200°C for 8-12 hours, and then calcine at 500-1000°C for 8-12 hours to obtain an ultra-high purity calcium fluoride product.

[0036] The beneficial effects of the technical solution of the embodiment of the present invention include:

[0037] The purification detection system provided in the embodiment of the present invention can help technicians complete a series of sample analyses in one purification experiment, thereby greatly improving the efficiency of analyzing the actual situation of the purification reaction and facilitating technicians to formulate more efficient, more economical and higher purity purification plans.

[0038] In general, the purification detection system provided in the embodiment of the present invention can help technicians to quickly detect and analyze the purification process, so as to more accurately grasp the actual progress of purification, which has positive significance for streamlining the purification process and eliminating inefficient links, and can help promote the high-efficiency, low-cost, and high-purity reform of purification technology. The 6N ultra-high-purity calcium fluoride production process for artificial lenses provided in the embodiment of the present invention can achieve a high degree of purification of calcium fluoride, and at the same time achieve accurate monitoring of the purification process, thereby improving the purification efficiency and ensuring the purification quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0040] Figure 1 A schematic diagram of the overall structure of a purification detection system provided in an embodiment of the present invention;

[0041] Figure 2 for Figure 1 A magnified image of area A;

[0042] Figure 3It is a schematic diagram of the structure of the control core of the purification detection system;

[0043] Figure 4 It is a structural schematic diagram of the bottom end of the control core;

[0044] Figure 5 It is a schematic diagram of the structure of the collection set;

[0045] Figure 6 A schematic diagram of a purification detection system installed in a purification reaction vessel;

[0046] Figure 7 This is a schematic diagram when the liquid outlet is just connected to a collection tank;

[0047] Figure 8 This is a schematic diagram of a liquid outlet just disconnected from a collection tank.

[0048] Description of reference numerals:

[0049] Control core 100; liquid outlet 110; matching tube 120; protrusion 130; one-way valve 140; collection sleeve 200; collection tank 210; stop plate 220; connecting column 230; delivery tube 300; purification reaction container 400; circulation pipeline 410. DETAILED DESCRIPTION

[0050] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0051] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0052] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0053] In addition, the terms "parallel", "vertical", etc. do not mean that the components must be absolutely parallel or vertical, but can be slightly tilted. For example, "parallel" only means that its direction is more parallel than "vertical", and does not mean that the structure must be completely parallel, but can be slightly tilted.

[0054] In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "setting", "installation" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be a communication between the two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0055] In order to overcome the shortcomings of the prior art, please refer to Figure 1 to Figure 6 This embodiment provides a purification detection system, which includes: a control core 100 and a collection sleeve 200.

[0056] The control core 100 is a hollow structure, and a liquid outlet 110 communicating with the internal space thereof is provided on the side wall of the control core 100. The liquid outlet 110 is arranged near one end of the control core 100, and the other end of the control core 100 is used to communicate with a circulation pipe 410 (not shown in the figure) of a purification reaction container 400 (not shown in the figure).

[0057] The inner diameter of the collecting sleeve 200 matches the outer diameter of the control core 100, and the inner wall of the collecting sleeve 200 is provided with a collecting groove 210, which continuously extends in a ring shape along the circumference of the collecting sleeve 200. A plurality of collecting grooves 210 are sequentially arranged at intervals along the axial direction of the collecting sleeve 200. In this embodiment, a plurality of collecting grooves 210 are evenly arranged at intervals along the axial direction of the collecting sleeve 200, and the collecting grooves 210 are arranged from one end of the collecting sleeve 200 to the other end of the collecting sleeve 200.

[0058] The outer wall of the control core 100 is threadedly matched with the inner wall of the collection sleeve 200, and the control core 100 and the collection sleeve 200 are rotationally sealed. The control core 100 and the collection sleeve 200 are coaxially arranged, and by rotating the control core 100 relative to the collection sleeve 200, the control core 100 can be rotated relative to the collection sleeve 200 and move along the axial direction of the collection sleeve 200. During the rotation of the control core 100, only the end of the control core 100 with the liquid outlet 110 can be matched in the collection sleeve 200, or the entire control core 100 can be basically completely entered into the collection sleeve 200.

[0059] Optionally, the control core 100 may be driven by a driving component (not shown in the figure). Optionally, when the driving component drives the control core 100, it is a uniform speed drive.

[0060] The collecting sleeve 200 is used to be fixedly installed in the purification reaction container 400. Figure 6As shown, during the circulation process, the liquid in the purification reaction container 400 is pumped into the circulation pipe 410, and the circulating liquid entering the circulation pipe 410 is sent to the control core 100 by the circulation pipe 410. The circulating liquid entering the control core 100 can enter the collection sleeve 200 from the liquid outlet 110, and finally return to the reaction system of the purification reaction container 400 from the end of the collection sleeve 200.

[0061] Specifically, the collection sleeve 200 is located below the liquid surface of the purification reaction container 400, that is, the liquid in the purification reaction container 400 needs to submerge the collection sleeve 200. The control core 100 is fitted to the collection sleeve 200 from the upper end of the collection sleeve 200, and a gap is left between the lower end of the collection sleeve 200 and the bottom of the purification reaction container 400.

[0062] In the initial state, the control core 100 is matched with the top of the collection sleeve 200, and the liquid outlet 110 of the control core 100 is located above the collection tank 210 at the top of the collection sleeve 200, and the liquid outlet 110 is just not connected to the collection tank 210 at the top. Figure 2 This is conducive to the full closure of the circulation pipeline 410.

[0063] After the circulation starts, the circulating fluid enters the control core 100, and the driving component drives the control core 100 to start rotating. After the control core 100 starts rotating, it moves synchronously at a certain speed toward the bottom of the collection sleeve 200 under the action of the thread. When the control core 100 starts to move along the axial direction of the collection sleeve 200, the liquid outlet 110 rotates along the circumference of the control core 100 with the control core 100, and the liquid outlet 110 also moves axially with the control core 100. Once the liquid outlet 110 moves axially, it is successfully connected to the collection tank 210 at the top of the collection sleeve 200, as shown in FIG. Figure 7 At this time, the circulating liquid can enter the collecting tank 210 through the liquid outlet 110 .

[0064] When the liquid outlet 110 is just connected to the collecting tank 210, the end of the control core 100 does not close the collecting tank 210, that is, the circulating liquid entering the collecting tank 210 can also flow along the axial direction of the collecting sleeve 200 and flow out from the end of the collecting sleeve 200 away from the control core 100. In this way, the circulating flow of the circulating liquid is achieved.

[0065] During the above-mentioned circulation process, the circulating liquid continuously enters the collection tank 210 and continuously returns to the purification reaction vessel 400 through the collection tank 210. This ensures that the circulating liquid entering the collection tank 210 always has the same composition and reaction process as the liquid phase of the main part of the purification reaction vessel 400.

[0066] As the control core 100 continues to move, the liquid outlet 110 will continue to move along the axial direction. If it continues, the liquid outlet 110 will gradually be disconnected from the collection groove 210. When the liquid outlet 110 is disconnected from a collection groove 210, the end of the control core 100 just closes the collection groove 210. Figure 8 shown.

[0067] In this way, when the top collection tank 210 is closed, the liquid phase therein will not return to the purification reaction container 400, but will be sealed in this collection tank 210. When the control core 100 finally moves to the bottom of the collection sleeve 200, all the collection tanks 210 in the collection sleeve 200 are closed, and along the height direction of the collection sleeve 200 from top to bottom, these collection tanks 210 store the liquid phase samples collected in chronological order.

[0068] When a certain reaction component is gradually and slowly added to the purification reaction container 400, the samples in these collection tanks 210 correspond to the states of different added amounts of the reagent, and can be used to analyze the purification effects of different added amounts of the reagent.

[0069] For the case where all the reaction components are added into the purification reaction vessel 400 at the beginning, the difference in the samples in these collection tanks 210 is the difference in collection time. At this time, when a collection tank 210 has just been closed by the control core 100, that is, when the collection of the liquid phase has just been completed, the liquid phase in this collection tank 210 can be discharged through the tube body for analysis of the purification effect under different purification reaction times.

[0070] The above design can help technicians complete a series of sample analyses in one purification experiment, thereby greatly improving the efficiency of analyzing the actual situation of the purification reaction and facilitating technicians to develop more efficient, more economical and higher purity purification plans.

[0071] In general, the purification detection system provided in this embodiment can help technicians to quickly detect and analyze the purification process, so as to more accurately grasp the actual progress of purification. It has positive significance for streamlining the purification process and eliminating inefficient links, and can help promote high-efficiency, low-cost, and high-purity reforms in purification technology.

[0072] It should be emphasized that when the liquid outlet 110 transports the circulating liquid to the collection tank 210, the liquid outlet 110 is in motion in the circumferential direction, which is conducive to ensuring the uniformity of the liquid phase in each collection tank 210 and keeping the liquid phase therein highly consistent with the main part in the purification reaction vessel 400.

[0073] In this embodiment, the purification detection system further includes: an analysis end (not shown in the figure) which is used to analyze the liquid phase collected and packaged in the collection tank 210 to determine the corresponding purification progress and effect.

[0074] The collection sleeve 200 is connected to the analysis end through a delivery tube 300 . The delivery tube 300 is in communication with the collection tank 210 . Each collection tank 210 is provided with a delivery tube 300 for delivering the circulating liquid in the collection tank 210 to the analysis end separately.

[0075] In addition, the purification detection system also includes: a controller (not shown in the figure).

[0076] The controller is used to determine the rotation speed of the driving component to drive the control core 100 according to the set cycle time, so that during the cycle time, the control core 100 can gradually enter the collection sleeve 200, and the control core 100 can just move from one end of the collection sleeve 200 to the other end of the collection sleeve 200. In this way, the high consistency of the analysis and detection work and the actual cycle process can be guaranteed, and at the same time, it can also ensure that the samples collected in the collection tank 210 can fully reflect the overall picture of the purification reaction process.

[0077] Optionally, a stop plate 220 spaced apart from the end surface of the collection sleeve 200 may be provided at the bottom end of the collection sleeve 200, the stop plate 220 is fixedly connected to the collection sleeve 200 via a connecting column 230, and the stop plate 220 is provided perpendicular to the central axis of the collection sleeve 200. When the control core 100 moves to abut against the stop plate 220, the liquid outlet 110 is located outside the collection sleeve 200, and all the collection slots 210 in the collection sleeve 200 are closed by the control core 100.

[0078] The stop plate 220 can indicate the end point of the movement of the control core 100 and prevent the control core 100 from causing damage to the purification reaction container 400 .

[0079] In order to facilitate the circulation pipe 410 to transport the circulation fluid to the control core 100, a matching pipe 120 is provided at one end of the control core 100 for communicating with the circulation pipe 410. The matching pipe 120 is communicated with the internal space of the control core 100. The matching pipe 120 is coaxially arranged with the control core 100. The matching pipe 120 can be rotatably matched with the control core 100 and is rotationally sealed with the control core 100. The control core 100 is communicated with the circulation pipe 410 through the matching pipe 120.

[0080] Furthermore, the end surface of the control core 100 at one end where the liquid outlet 110 is provided has a protrusion 130, which is arranged close to the edge of the control core 100, and the side wall of the protrusion 130 is in contact with the inner wall of the collection sleeve 200. The internal space of the collection sleeve 200 extends to the protrusion 130, and the liquid outlet 110 is provided at one side of the protrusion 130 for contacting with the inner wall of the collection sleeve 200. The protrusion 130 and the end of the control core 100 together form an oblique truncated cylindrical structure.

[0081] With this design, the liquid outlet 110 is located at the protrusion 130, which makes the liquid outlet 110 closer to the main body of the control core 100 and can be connected with the collection tank 210 more "in advance". The liquid entering the collection tank 210 from the liquid outlet 110 will flow along the collection tank 210 under the obstruction of the protrusion 130, and will flow out from the side of the collection tank 210 away from the protrusion 130 (the side not obstructed by the protrusion 130), which further promotes the full flow of the circulating liquid in the collection tank 210, avoids the local concentration difference of the liquid in the collection tank 210, and ensures the accuracy of the analysis result.

[0082] Relying on the oblique cylindrical structure at the end of the control core 100, the control core 100 is further provided with a one-way valve 140, which is arranged on the inclined end surface of the oblique cylindrical structure. The inlet end of the one-way valve 140 is communicated with the internal space of the control core 100, and the outlet end of the one-way valve 140 is communicated with the collection sleeve 200. In the axial direction of the control core 100, the maximum protrusion 130 of the protrusion 130 extends beyond the exposed part of the one-way valve 140.

[0083] In this embodiment, the liquid outlet 110 will not be connected to two collection tanks 210 at the same time. The liquid outlet 110 will be connected to the next collection tank 210 only after it is completely disconnected from the previous collection tank 210 as the control core 100 continues to move. Therefore, the liquid outlet 110 may be in a state of not being connected to any collection tank 210. In this state, the circulating liquid cannot leave the control core 100 from the liquid outlet 110, but can leave the control core 100 through the one-way valve 140, thereby ensuring the normal circulation.

[0084] Since the maximum protrusion 130 of the protrusion 130 extends beyond the exposed portion of the one-way valve 140 along the axial direction of the control core 100 , the protrusion 130 can also effectively protect the one-way valve 140 to prevent the one-way valve 140 from colliding with the stop plate 220 .

[0085] It should be noted that the sample collection amount of each collection groove 210 can be changed by controlling the radial depth of the collection groove 210 in the collection sleeve 200, and the sample collection time point of each collection groove 210 can be controlled by adjusting the axial width of the collection groove 210 in the collection sleeve 200 and the axial spacing between two adjacent collection grooves 210 in the collection sleeve 200.

[0086] This embodiment also provides the application of the above-mentioned purification detection system in the production of 6N ultra-high purity calcium fluoride for artificial lenses. During the production of 6N ultra-high purity calcium fluoride for artificial lenses, the purification detection system can sample and monitor the purification process during the purification operation of the liquid phase system.

[0087] This embodiment also provides a 6N ultra-high purity calcium fluoride production process for artificial lenses, including: when performing purification operation on the liquid phase system, the collection sleeve of the purification detection system is fixedly installed in the reactor, and the circulation pipeline of the reactor is connected to the control core of the purification detection system. According to the set purification time, the speed of the driving component driving the control core is determined, so that within the purification time, the control core can gradually enter the collection sleeve and the control core can just move from one end of the collection sleeve to the other end of the collection sleeve.

[0088] Specifically, the production process of 6N ultra-high purity calcium fluoride for artificial lenses includes the following steps:

[0089] S1, react nitric acid and calcium sand, add ammonia water to adjust the pH value to 5-6, and then settle for 24 hours. Under this pH condition, the iron in the calcium nitrate solution will be converted into iron hydroxide and precipitated, thereby achieving the purpose of removing iron impurities. Exemplarily, as shown in Table 1, the change in the content of iron impurities after treatment with S1 is shown.

[0090] Table 1: Changes in the content of iron impurities

[0091] sample Calcium sand Nitric acid solution before filtration After nitric acid solution is filtered Iron / ppm 166.1 102.28 0.55

[0092] S2, add calcium hydroxide to the supernatant after sedimentation in S1, adjust the pH value to 10-11, stop stirring after stirring cycle, settle for 48h, and take the supernatant. The main purpose of this step is to remove magnesium impurities. Exemplarily, as shown in Table 2, the change in the content of magnesium impurities after treatment with S2 is shown.

[0093] Table 2: Changes in the content of magnesium impurities

[0094] sample Calcium sand Calcium nitrate before filtration Calcium nitrate after filtration Magnesium / ppm 807.9 520.8 5.22

[0095] S3, adding an extractant to the supernatant of S2, stirring, standing and separating the extractant. The extractant includes: any one of di(2-ethylhexyl)phosphoric acid, bis(2,4,4-trimethylpentyl)phosphonic acid, diisooctyl oxalate and cyclohexane acid.

[0096] The extractant is for strontium impurities and magnesium impurities. For example, as shown in Table 3, the changes in the contents of strontium impurities and magnesium impurities after treatment with S3 are shown.

[0097] Table 3: Changes in the content of strontium impurities and magnesium impurities

[0098] sample Calcium sand Calcium nitrate before filtration Calcium nitrate after filtration Magnesium / ppm 807.9 5.22 0.11 Strontium / ppm 131.1 80.03 49.10

[0099] S4. Add potassium hydroxide to the system separated in S3 (neutralization reaction), separate the precipitate from the supernatant, and obtain calcium hydroxide precipitate.

[0100] S5, washing the calcium hydroxide precipitate with pure water. The calcium hydroxide precipitate can be repeatedly washed with pure water until there are no strontium and potassium impurities in the washing liquid. Exemplarily, as shown in Table 4, the content of metal impurities in the calcium hydroxide precipitate after S5 treatment is shown.

[0101] Table 4: Changes in the content of metal impurities

[0102] sample Strontium / ppm Potassium / ppm Calcium sand 131.1 7.02 Calcium Nitrate 49.10 4.13 One wash water 8.55 1098 Secondary cleaning water 4.97 693.8 Three times washing water 2.87 291.7 Four times cleaning water 1.95 49.96 Five times cleaning water 0.77 13.81 Six times washing water 0.34 1.69 Seven times washing water 0.07 0.11 Eight times cleaning water ND ND Calcium hydroxide precipitation 0.48 0.23

[0103] S6. Reacting nitric acid with the washed calcium hydroxide precipitate to obtain a calcium nitrate solution.

[0104] S7. Calcium fluoride is reacted with hydrofluoric acid and calcium nitrate solution, stirring is stopped after the reaction, the supernatant is removed after sedimentation, nitric acid is added to stir and wash the sedimentation part, the sedimentation part is filtered to obtain a precipitate, and the precipitate is washed with pure water until the pH value of the washing liquid is 6-7 to obtain calcium fluoride slurry. The calcium fluoride slurry can be further reduced in water content by filter press treatment.

[0105] S8. Dehydrate the calcium fluoride slurry at 80-200°C for 8-12 hours, and then calcine at 500-1000°C for 8-12 hours to obtain an ultra-high purity calcium fluoride product. For example, as shown in Table 5, the metal impurity data in the ultra-high purity calcium fluoride product are shown.

[0106] Table 5: Metal impurity data

[0107] sample Calcium hydroxide Calcium fluoride (before nitric acid cleaning) Calcium fluoride (after nitric acid cleaning) Iron / ppm 1.21 1.25 0.15 Magnesium / ppm 0.24 0.30 0.12 Strontium / ppm 0.48 0.50 0.23 Potassium / ppm 0.23 0.24 0.09 Lead / ppm ND ND ND Sodium / ppm 0.15 0.16 0.11 Barium / ppm 0.07 0.08 0.05

[0108] In S2, during the stirring cycle, the collection sleeve 200 of the purification detection system is fixedly installed in the reactor of S2, and the circulation pipe 410 of the reactor of S2 is connected to the control core 100 of the purification detection system.

[0109] According to the set stirring cycle time, the rotation speed of the driving component to drive the control core 100 is determined so that within the stirring cycle time, the control core 100 can gradually enter the collecting sleeve 200 and the control core 100 can just move from one end of the collecting sleeve 200 to the other end of the collecting sleeve 200.

[0110] During the circulation process, when the control core 100 moves, the collection tanks 210 are closed one by one from top to bottom and the sample collection is completed. When a collection tank 210 is just closed, the sample in it is immediately transported to the analysis end for analysis by the delivery tube 300, so as to analyze the purification conditions at different time points during the circulation process, thereby helping technicians to select the appropriate circulation time to take into account both the purification effect and the purification efficiency.

[0111] In summary, the purification detection system provided in the embodiment of the present invention can help technicians to quickly detect and analyze the purification process, so as to more accurately grasp the actual progress of purification, which has positive significance for streamlining the purification process and eliminating inefficient links, and can help promote the high-efficiency, low-cost, and high-purity reform of purification technology. The 6N ultra-high-purity calcium fluoride production process for artificial lenses provided in the embodiment of the present invention can achieve a high degree of purification of calcium fluoride, and at the same time achieve accurate monitoring of the purification process, which improves the purification efficiency and ensures the purification quality.

[0112] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A purification detection system, characterized in that: include: Control core and collection sleeve; The control core is a hollow structure, and a liquid outlet communicating with the internal space of the control core is provided on the side wall of the control core, the liquid outlet is arranged near one end of the control core, and the other end of the control core is used to communicate with the circulation pipeline of the purification reaction container; The inner diameter of the collecting sleeve is matched with the outer diameter of the control core, and the inner wall of the collecting sleeve is provided with a collecting groove, which continuously extends into a ring shape along the circumference of the collecting sleeve; along the axial direction of the collecting sleeve, a plurality of the collecting grooves are sequentially spaced apart; The outer wall of the control core is threadedly matched with the inner wall of the collecting sleeve, the control core and the collecting sleeve are rotationally sealed, and the control core is driven by a driving component; The collecting sleeve is used to be installed in the purification reaction container, and during the circulation process, the circulating liquid enters the control core through the circulating pipe; Wherein, when the liquid outlet is connected with the collecting tank, the circulating liquid enters the collecting tank through the liquid outlet; when the liquid outlet is just connected with one of the collecting tanks, the end of the control core does not close the collecting tank; when the liquid outlet is just disconnected from one of the collecting tanks, the end of the control core just closes the collecting tank; The end surface of one end of the control core where the liquid outlet is opened has a protrusion, the protrusion is arranged close to the edge of the control core, and the side wall of the protrusion is in contact with the inner side wall of the collection sleeve; the internal space of the collection sleeve extends to the protrusion, and the liquid outlet is opened on one side of the protrusion for contacting with the inner side wall of the collection sleeve; The protrusion and the end of the control core together form an oblique truncated cylindrical structure; The control core is also provided with a one-way valve, which is provided on the inclined end surface of the oblique cylindrical structure; the inlet end of the one-way valve is communicated with the internal space of the control core, and the outlet end of the one-way valve is communicated with the collecting sleeve; Wherein, along the axial direction of the control core, the maximum protruding portion of the protruding portion extends beyond the exposed portion of the one-way valve.

2. The purification detection system according to claim 1, characterized in that: The purification detection system further comprises: an analysis end; The collecting sleeve is connected to the analysis end through a delivery tube, the delivery tube is communicated with the collecting tank, and each collecting tank is correspondingly provided with a delivery tube for delivering the circulating liquid in the collecting tank to the analysis end separately.

3. The purification detection system according to claim 1, characterized in that: The purification detection system further includes: a controller; The controller is used to determine the rotation speed of the driving component to drive the control core according to the set cycle time, so that during the cycle time, the control core can gradually enter the collection sleeve and the control core can just move from one end of the collection sleeve to the other end of the collection sleeve.

4. The purification detection system according to claim 1, characterized in that: A mating tube is provided at one end of the control core for communicating with the circulation pipeline. The mating tube is communicated with the internal space of the control core. The mating tube is coaxially arranged with the control core. The mating tube can be rotatably matched with the control core and is rotationally sealed with the control core. The control core is communicated with the circulation pipeline through the mating tube.

5. Use of the purification detection system according to any one of claims 1 to 4 in the production of 6N ultra-high purity calcium fluoride for artificial lenses.

6. A process for producing 6N ultra-high purity calcium fluoride for artificial lenses, characterized in that: include: When performing purification operation on the liquid phase system, the collection sleeve of the purification detection system according to any one of claims 1 to 4 is fixedly installed in the reactor, and the circulation pipeline of the reactor is connected to the control core of the purification detection system; According to the set purification time, the rotation speed of the driving component driving the control core is determined so that within the purification time, the control core can gradually enter the collection sleeve and the control core can just move from one end of the collection sleeve to the other end of the collection sleeve.

7. The process for producing 6N ultra-high purity calcium fluoride for artificial lens according to claim 6, characterized in that: The steps include: S1. React nitric acid and calcium sand, add ammonia water to adjust the pH value to 5-6, and then settle for 24 hours; S2, add calcium hydroxide to the supernatant after sedimentation in S1, adjust the pH value to 10-11, stop stirring after the stirring cycle, let it settle for 48 hours, and take the supernatant; During the stirring cycle, the collection sleeve of the purification detection system is fixedly installed in the reactor, and the circulation pipeline of the reactor is connected to the control core of the purification detection system; according to the set stirring cycle time, the speed of the control core driven by the driving component is determined, so that within the stirring cycle time, the control core can gradually enter the collection sleeve and the control core can just move from one end of the collection sleeve to the other end of the collection sleeve; S3, adding an extractant to the supernatant of S2, stirring, standing and stratifying, and separating the extractant; the extractant comprises: any one of di(2-ethylhexyl)phosphoric acid, bis(2,4,4-trimethylpentyl)phosphonic acid, diisooctyl oxalate and cyclohexane acid; S4, adding potassium hydroxide to the system separated in S3, separating the precipitate from the supernatant to obtain calcium hydroxide precipitate; S5, washing the calcium hydroxide precipitate with pure water; S6, reacting nitric acid with the washed calcium hydroxide precipitate to obtain a calcium nitrate solution; S7, using hydrofluoric acid and the calcium nitrate solution to react with calcium fluoride, stopping stirring after the reaction, removing the supernatant after sedimentation, adding nitric acid to stir and wash the sedimentation part, filtering the sedimentation part to obtain a precipitate, and washing the precipitate with pure water until the pH value of the washing liquid is 6-7, thereby obtaining a calcium fluoride slurry; S8. Dehydrate the calcium fluoride slurry at 80-200° C. for 8-12 hours, and then calcine at 500-1000° C. for 8-12 hours to obtain an ultra-high purity calcium fluoride product.

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