Hydrofluoric acid wastewater recovery system capable of extracting industrial raw material

Abstract

To provide a recovery system for extracting industrial raw materials from wastewater containing hydrofluoric acid.SOLUTION: There is provided a hydrofluoric acid wastewater recovery system capable of extracting industrial raw materials, including: a wastewater collection tank 90, an activated carbon filter 91, a capacitive deionizer 92, a low-concentration collection tank 60, at least one filter 80, a high-concentration collection tank 30, a reactor 10, and a dehydrator 50. The wastewater collection tank contains hydrofluoric acid wastewater. The activated carbon filter is connected to the wastewater collection tank. The capacitive deionizer is connected to the activated carbon filter. The low concentration collection tank is connected to the capacitive deionizer and receives low concentration fluoride wastewater. The filter is connected to the low-concentration collection tank and filters the low-concentration fluoride wastewater to form recovered water. The high-concentration collection tank is connected to the capacitive deionizer and receives the high-concentration fluorine wastewater. The reactor is connected to the high-concentration collection tank. The dehydrator is connected to the reactor.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a wastewater recovery system, and more particularly to a recovery system for extracting industrial raw materials from wastewater containing hydrofluoric acid. Background Technology

[0002] Taiwan has developed high-tech industries and is a major base for research, development, and manufacturing of high-tech industries such as semiconductors and displays around the world. In the manufacturing processes of the integrated circuit semiconductor industry, liquid crystal display panel industry, and solar energy industry, a large amount of solution containing hydrofluoric acid is used for etching or surface cleaning. After etching or cleaning, hydrofluoric acid wastewater is generated, and the fluorine ion concentration in this hydrofluoric acid wastewater is about 1000 to 3500 mg / L, and sometimes exceeds 10000 mg / L. However, this hydrofluoric acid wastewater containing high-purity fluorine ions cannot be directly discharged because fluorine is a poison that is ingested from water or food and accumulates in the body. If a large amount of fluorine is ingested, the calcium-phosphorus metabolic balance is disrupted, and bone fluorosis, which is a symptom of weakened teeth, rashes, and deformation of the skeleton and joints, may occur. This hydrofluoric acid wastewater containing high-purity fluorine ions may enter the wastewater treatment system. In conventional technology, calcium fluoride sludge is generated by chemical coagulation to reduce the fluorine ion concentration in the hydrofluoric acid wastewater to meet the wastewater discharge standard, but the large amount of sludge generated must be buried or otherwise treated at great expense. Therefore, a technology that can reuse this hydrofluoric acid wastewater as a resource is required.

[0003] "Method for Producing Calcium Fluoride from Wastewater Containing Hydrofluoric Acid, Hexafluorosilicic Acid and Hexafluoroaluminate" in Patent Document 1 added potassium fluoride to wastewater containing hydrofluoric acid, hexafluorosilicic acid and hexafluoroaluminate, and with the assistance of chemicals such as ammonia, calcium hydroxide, and flocculants, it was allowed to stand for sedimentation and then filtered to obtain calcium fluoride. However, the steps of the treatment method in Patent Document 1 are complex. In order to produce calcium fluoride through the precipitation and filtration process, the chemicals and wastewater always had to be mixed at different weight ratios to form a mixed solution and the pH value had to be adjusted.

[0004] "Treatment Method for Fluorine-Containing Wastewater and Its Treatment Agent" in Patent Document 2 added a mixed chemical agent containing a compound containing aluminum or sodium and its combination to the fluorine-containing waste liquid after standing, adjusted the pH value of the fluorine-containing waste liquid, removed the cations in the fluorine-containing waste liquid, and then added a treatment agent composed of a compound containing aluminum, sodium, or chlorine to perform a chemical coagulation action on the fluoride ions and chemicals in the fluorine-containing waste liquid to form cryolite precipitate and achieve other uses. However, the steps of the treatment method in Patent Document 2 are complex. This step of separately adding the mixed chemical agent, adjusting it to a suitable pH value, and helping to remove the interference of cations forms various metal hydroxides in the fluorine-containing waste liquid, and it is necessary to remove the various metal hydroxides to prevent subsequent interference. Adding an aluminum compound further to precipitate the formed cryolite increases the cost when adding chemicals separately, and since the various metal hydroxides formed also have to be removed, the generation of waste also increases.

[0005] "Method for Recovering Fluorine from Hydrofluoric Acid Waste Liquid and Producing Fluorosilicate" in Patent Document 3 reacted the waste liquid containing hydrofluoric acid with a compound containing silicon to produce hexafluorosilicic acid (H 2 SiF 6After generating waste liquid containing ), the concentration of the waste liquid containing hexafluorosilicic acid is adjusted, and an alkali or alkali metal salt containing sodium or potassium is added to generate a precipitate of fluorosilicate. Then, sodium fluorosilicate or potassium fluorosilicate is separated from the waste liquid and dried to form a recoverable product of sodium fluorosilicate or potassium fluorosilicate. However, in the treatment method of Patent Document 3, there is an operation limit of maintaining the waste liquid containing hydrofluoric acid and the waste liquid containing hexafluorosilicic acid at 5 to 15% by weight. If it is too low or too high, a highly economical fluorosilicate cannot be generated, and the operating cost increases.

[0006] With the increasing awareness of environmental protection, the concepts of energy conservation and reduction of carbon dioxide emissions have become important. The technologies disclosed so far cannot recover and utilize fluorine-containing wastewater without adding various solvents and chemical aids to adjust the pH value, etc. As a result, the overall treatment cost increases. Additionally, adding solvents and chemical aids separately conflicts with the concepts of environmental protection, energy conservation, and reduction of carbon dioxide emissions, and may also generate related waste liquid or waste.

[0007] In view of this situation, the inventor has completed the present invention with various ideas based on years of manufacturing and design experience and knowledge in related fields.

Prior Art Documents

Patent Documents

[0008]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0009] The main object of the present invention is to control the liquid flow pattern and flow rate of the contact reaction between a sodium aluminum compound and high-concentration fluorine-containing wastewater by a dispersion plate and a control plate in a system reaction tank, and to monitor the pH value and fluorine ion concentration of a mixed water sample of high-concentration fluorine-containing wastewater and a sodium aluminum compound by a pH value / fluorine ion detection section in which a loop form communicates with the system reaction tank, effectively control the factors affecting the crystal purity of cryolite during the operation process of the system, enable the system to stably form crystal purity, recycle and reuse cryolite, increase the recovery rate of fluorine ions, and obtain highly economical cryolite crystals, and provide a hydrogen fluoride acid wastewater recovery system capable of extracting industrial raw materials.

Means for Solving the Problems

[0010] The present invention is made to solve at least a part of the above problems and can be realized as the following application examples (1) to (11). Application Example (1) A hydrogen fluoride acid wastewater recovery system capable of extracting industrial raw materials, comprising a wastewater collection tank, an activated carbon filtration device, a capacitive deionization device, a low-concentration collection tank, at least one filtration device, a high-concentration collection tank, a reaction device, and a dehydration device, The wastewater collection tank stores hydrogen fluoride acid wastewater, The activated carbon filtration device is connected to the wastewater collection tank, filters the hydrogen fluoride acid wastewater, and generates first wastewater, The capacitive deionization device is connected to the activated carbon filtration device and has a plurality of electrodes having opposite charges, By moving the ions in the first wastewater toward a plurality of corresponding electrodes with opposite charges, low-concentration fluorine-containing wastewater is formed, By desorbing and releasing ions from a plurality of electrodes, high-concentration fluorine-containing wastewater is formed, The low-concentration collection tank is connected to the capacitive deionization device and stores low-concentration fluorine-containing wastewater, The filtration device is connected to the low-concentration collection tank, filters low-concentration fluorine-containing wastewater to form recovered water, and the recovered water can be returned to the factory and reused internally. The high-concentration collection tank is connected to the capacitive deionization device and stores the high-concentration fluorine-containing wastewater. The reaction device is connected to the high-concentration collection tank and generates cryolite and third wastewater through the reaction of the added sodium aluminum-containing compound and the high-concentration fluorine-containing wastewater. The dehydration device is connected to the reaction device and separates the cryolite and the third wastewater. A hydrogen fluoride acid wastewater recovery system capable of extracting industrial raw materials. Application Example (2) The capacitive deionization device is a CDI (Capacitive De-Ionization) or a thin-film capacitive deionization device. The sodium aluminum-containing compound is sodium aluminate. The hydrogen fluoride acid wastewater recovery system capable of extracting industrial raw materials according to the Application Example (1). Application Example (3) The ions in the first wastewater include fluoride ions and hydrogen ions. The fluoride ion concentration in the high-concentration fluorine-containing wastewater is higher than that in the low-concentration fluorine-containing wastewater. The fluoride ion concentration in the high-concentration fluorine-containing wastewater is higher than that in the hydrofluoric acid wastewater. The hydrogen fluoride acid wastewater recovery system capable of extracting industrial raw materials according to the Application Example (1). Application Example (4) The filtration device is connected to the wastewater collection tank, or the low-concentration collection tank, or both the low-concentration collection tank and the wastewater collection tank. The filtration device is a reverse osmosis (RO) device or a thin-film capacitive deionization device. The hydrogen fluoride acid wastewater recovery system capable of extracting industrial raw materials according to the Application Example (1). Application Example (5) It further includes a control processor. The reaction device has a top tank opening and a bottom outlet corresponding to each other, Inside the reaction device, there is a dispersion plate having a plurality of liquid holes and a control plate located on the dispersion plate and having a plurality of through holes. Inside the reaction device, the dispersion plate and the control plate are installed at intervals, forming an upper dosing space and a lower reaction space. The upper dosing space has a sodium aluminate level gauge. The lower reaction space communicates with a discharge control section through the bottom outlet, and discharges a mixed water sample formed by the sodium aluminum compound and the high-concentration fluorine-containing wastewater. The mixed water sample generates the cryolite and the third wastewater by reaction. The sodium aluminate level gauge and the discharge control section are electrically controlled by the control processor. The discharge control section is connected to the dehydration device and the waste liquid tank to separate the cryolite and the third wastewater. The dehydration device and the waste liquid tank are electrically controlled by the control processor. The dehydration device communicates with the discharge control section of the reaction device. The waste liquid tank collects the third wastewater discharged by the dehydration device, and is a hydrofluoric acid wastewater recovery system capable of extracting industrial raw materials according to the application example (1). Application example (6) The lower reaction space of the reaction device has a hydrofluoric acid level gauge electrically controlled by the control processor. The discharge control section of the reaction device has a flow control valve and a ball valve. A discharge flow path is provided between the flow control valve and the bottom outlet of the reaction device. The discharge flow path is controlled by the ball valve. The flow control valve and the ball valve of the discharge control section and the ball valve of the discharge flow path are electrically controlled by the control processor. It further includes a sodium aluminate chemical tank and a pH value / fluoride ion detection section, The sodium aluminate chemical tank is electrically controlled by the batch metering control section by the control processor, and the aluminum sodium-containing compound is added into the upper dosing space of the reactor, The pH value / fluoride ion detection section has a pH meter and a fluorometer that communicate with each other and are electrically controlled by the control processor. The mixed water sample is supplied to the pH meter and the fluorometer to detect the pH value and fluoride content of the mixed water sample discharged by the discharge control section, The pH meter has a first flow path communicating with the bottom of the lower reaction space of the reactor, The fluorometer has a second flow path communicating with the top of the lower reaction space, and the mixed water sample is refluxed or discharged to the reactor. The hydrogen fluoride acid wastewater recovery system capable of extracting industrial raw materials according to the application example (5) is characterized in that. Application example (7) The plurality of liquid holes of the dispersion plate are formed in a cross-shaped radial pattern from the center of the circle, The plurality of through holes of the control plate are composed of a first through hole group, a second through hole group, and a third through hole group, The first through hole group, the second through hole group, and the third through hole group are formed in a cross-shaped radial pattern from the center of the circle of the control plate, and an angle is formed between adjacent radial directions, The first through hole group has the same number of through holes as the liquid holes of the dispersion plate, The second through hole group and the third through hole group have different numbers of through holes less than the number of liquid holes of the dispersion plate, The dispersion plate has a plurality of positioning holes, The control plate has three sets of position restraint holes corresponding to the positions and numbers of the positioning holes of the dispersion plate, and an angle is formed between each set of the position restraint holes, One set of the position restraint holes of the control plate and the positioning holes of the dispersion plate can be aligned, The dispersion plate and the control panel are characterized in that a plurality of positioning pins corresponding to the number of the positioning holes are inserted and fixed, and the hydrogen fluoride acid wastewater recovery system capable of extracting industrial raw materials according to the application example (5) described above. Application example (8) The high-concentration collection tank has a liquid level gauge and a discharge valve. The batch quantitative control section of the high-concentration collection tank has a transport pump. Two ball valves are respectively provided between the transport pump and between the high-concentration collection tank and the reaction device. The batch quantitative control section of the high-concentration collection tank is provided with a hydrogen fluoride acid flow meter at a location adjacent to the reaction device. In the high-concentration collection tank, the liquid level gauge, the transport pump, the two ball valves, the hydrogen fluoride acid flow meter, and the discharge valve are electrically controlled by the control processor. The sodium aluminate chemical agent tank has a liquid level gauge and a discharge valve. The batch quantitative control section of the sodium aluminate chemical agent tank has a transport pump. Two ball valves are respectively provided between the transport pump and between the sodium aluminate chemical agent tank and the reaction device. The batch quantitative control section of the sodium aluminate chemical agent tank is provided with a sodium aluminate flow meter at a location adjacent to the reaction device. In the sodium aluminate chemical agent tank, the liquid level gauge, the transport pump, the two ball valves, the sodium aluminate flow meter, and the discharge valve are electrically controlled by the control processor. The first flow path of the pH value / fluoride ion detection section has a measurement pump. A flow control valve and a ball valve are provided between the reaction device and the measurement pump. A ball valve and a clean water input section are provided between the measurement pump and the pH meter. The clean water input section has a flow control valve for controlling the amount of clean water input, The second flow path has a reflux control valve, The fluorometer has a third flow path, The third flow path has a discharge control valve and a ball valve to control the discharge of waste liquid, In the pH value / fluoride ion detection section, the measurement pump, the two flow control valves, the three ball valves, and the discharge control valve are electrically controlled by the control processor, The end opening of the second flow path communicating with the inside of the reaction device is provided from the upper tank wall of the lower reaction space of the reaction device to the upper tank center of the lower reaction space, The waste liquid tank has a liquid level gauge, a discharge valve, and a low-concentration fluoride wastewater output section, A ball valve for controlling the flow rate of the third wastewater is provided between the waste liquid tank and the dehydration device, The low-concentration fluoride wastewater output section has a transport pump and two ball valves, one of which is provided between the transport pump and the waste liquid tank, and the other is provided at the discharge end of the transport pump connecting to the wastewater output section, The hydrogen fluoride acid wastewater recovery system capable of extracting industrial raw materials according to (6) above, wherein in the waste liquid tank, the liquid level gauge, the discharge valve, the transport pump, and the three ball valves are electrically controlled by the control processor. Application Example (9) The hydrogen fluoride acid wastewater recovery system capable of extracting industrial raw materials according to Application Example (6) above is installed on an overflow prevention base, An overflow prevention body is provided on the peripheral side of the overflow prevention base, and it has a leak detection device electrically controlled by the control processor and a drain valve provided at the bottom of the overflow prevention base, It further includes a seed crystal storage tank, The seed crystal storage tank stores seed crystals inside and is installed in the fourth flow path, The fourth flow path communicates with the reactor and its discharge control section, and a transport pump is installed between the seed crystal storage tank and the discharge control section, the fourth flow path guides the mixed water sample discharged by the discharge control section to the seed crystal storage tank and then refluxes it to the reactor, and introduces the seed crystal into the reactor, and the hydrogen fluoride acid wastewater recovery system capable of extracting industrial raw materials according to the application example (6) described above. Application example (10) The control processor executes a control method including a parameter setting step, a high-concentration fluorine wastewater injection step, an aluminum sodium-containing compound addition step, a step of standing the mixed water sample, a step of supplying the mixed water sample to the pH value / fluoride ion detection section, a reaction end point determination step, and a solid-liquid separation step. In the parameter setting step, the control processor sets parameter items and numerical ranges of the parameter items, installs the dispersion disk and the control disk based on the flow rate needs of the aluminum sodium-containing compound, and controls the flow rate at which the aluminum sodium-containing compound falls into the lower reaction space. In the high-concentration fluorine wastewater injection step, the batch quantitative control section of the high-concentration collection tank is activated, and based on the set value of the parameter setting step, the high-concentration fluorine wastewater is injected into the lower reaction space of the reactor. In the aluminum sodium-containing compound addition step, after the high-concentration fluorine wastewater is completely injected into the reactor, the batch quantitative control section of the sodium aluminate chemical tank is activated, and based on the set value of the parameter setting step, the aluminum sodium-containing compound is added into the upper dosing space of the reactor to form the mixed water sample. In the step of standing the mixed water sample, based on the set value of the parameter setting step, the calculation of the reaction standing time is started. In the step of supplying the mixed water sample to the pH value / fluoride ion detection section, when the reaction standing time measurement is completed, the pH value / fluoride ion detection section is activated, the mixed water sample in the reactor is supplied into the pH value / fluoride ion detection section, the pH value and fluoride ion concentration of the mixed water sample are read, and the mixed water sample is refluxed to the reactor. In the reaction end point determination step, the control processor determines the reaction end point based on the pH value and fluoride ion concentration of the read mixed water sample. When the reaction has not reached the reaction end point, the pH value / fluoride ion detection section closing step and the fine adjustment step of the sodium aluminum-containing compound are performed. Based on the parameters set in the parameter setting step and the read pH value, a trace amount of the sodium aluminum-containing compound is added to the reactor, and until the reaction reaches the reaction end point, the steps of adding the sodium aluminum-containing compound, standing the mixed water sample, supplying the mixed water sample to the pH value / fluoride ion detection section, and the reaction end point determination step are repeatedly performed. In the solid-liquid separation step, when the reaction reaches the reaction end point, after activating the discharge control section of the reactor, the crystal dehydration collection step and the third waste water discharge step are performed. After completion, the discharge control section closing step of the reactor is performed. The hydrogen fluoride acid waste water recovery system capable of extracting industrial raw materials according to the application example (9) described above, characterized in that. Application example (11) The control method further includes an automatic mode determination step. The control processor presets the current operation to an automatic mode or a manual mode. In the case of the automatic mode, automatic control is performed by the control processor, starting from the high-concentration fluoride waste water injection step, and the above steps are repeatedly executed. When in manual mode, the control processor stops the automatic control, returns to the parameter setting step, and starts the automatic control after the parameter setting is completed. The hydrogen fluoride acid wastewater recovery system according to the application example (10) is capable of extracting industrial raw materials.

Advantages of the Invention

[0011] The hydrogen fluoride acid wastewater recovery system capable of extracting industrial raw materials of the present invention controls the liquid flow pattern and flow rate in which a sodium aluminum compound and high-concentration fluorine wastewater come into contact and react through a dispersion plate and a control plate in the system reaction tank. The pH value / fluoride ion detection section in which the loop form communicates with the system reaction tank monitors the pH value and fluoride ion concentration of the mixed water sample of the high-concentration fluorine wastewater and the sodium aluminum compound, effectively controls the factors affecting the crystal purity of cryolite during the operation of the system, enables the system to stably form crystal purity, provides cryolite for recycling and reuse, increases the recovery rate of fluoride ions, and can obtain high-economy cryolite crystals.

Brief Description of the Drawings

[0012]

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Figure 11

Mode for Carrying Out the Invention

[0013] In order to more fully and clearly disclose the technical means of the present invention and the effects achievable thereby, the present invention will be described in detail below in conjunction with the disclosed accompanying drawings and reference numerals.

[0014] Refer to FIG. 11. As shown in FIG. 11, a hydrofluoric acid wastewater recovery system capable of extracting industrial raw materials according to an embodiment of the present invention includes a wastewater collection tank 90, an activated carbon filtration device 91, a capacitive deionization device 92, a low-concentration collection tank 60, at least one filtration device 80, a high-concentration collection tank 30, a reaction device 10, a dehydration device 50, a pH value / fluoride ion detection section 40, a sodium aluminate chemical agent tank 20, a waste liquid tank 81, and a control processor A (refer to FIG. 4) for electrically controlling the aforementioned device mechanisms.

[0015] Refer to FIG. 3. As shown in FIG. 3, a hydrogen fluoride acid wastewater recovery system capable of extracting industrial raw materials according to an embodiment of the present invention is installed entirely on an overflow prevention base 70. An overflow prevention body 71 for preventing liquid from leaking out and spreading is provided on the peripheral side of the overflow prevention base 70, and it has a control processor A, a leak detection device 72 for electrically controlling, and a drain valve 73 provided at the bottom of the overflow prevention base 70. The leak detection device 72 detects the presence or absence of liquid leakage, and when liquid leaks, the drain valve 73 is electrically activated to discharge the liquid from the overflow prevention base 70.

[0016] Refer to FIGS. 1 and 2. As shown in FIGS. 1 and 2, the wastewater collection tank 90 stores and purifies the hydrogen fluoride acid wastewater 901. In this embodiment, the wastewater collection tank 90 is connected to an activated carbon filtration device 91.

[0017] Refer to FIGS. 1 and 2. As shown in FIGS. 1 and 2, the activated carbon filtration device 91 communicates with the wastewater collection tank 90. The activated carbon filtration device 91 filters the hydrogen fluoride acid wastewater 901 from the wastewater collection tank 90. The activated carbon filtration device 91 has a porous structure, and its structure is a six-ring compound deposit formed by carbon, so it has the characteristics of a large amount of micropore volume and a high specific surface area. The activated carbon filtration device 91 has the effects of deodorization, color adsorption, and chlorine adsorption. In the present invention, it is not necessary to add any chemical agents during the process of the hydrogen fluoride acid wastewater 901 from the wastewater collection tank 90 to the activated carbon filtration device 91. The organic constituents in the hydrogen fluoride acid wastewater 901 are removed by the adsorbability of the activated carbon filtration device 91. This adsorbability includes, for example, physical adsorption actions such as adsorption by Van der waals force, chemical bonding, or the attractive force of surface static charges. The residual disinfectants in the hydrogen fluoride acid wastewater 901 are removed by the catalyst of the activated carbon to generate the first wastewater 911.

[0018] Refer to FIGS. 1 and 2. As shown in FIGS. 1 and 2, the capacitive deionization device 92 communicates with the activated carbon filtration device 91. The capacitive deionization device 92 filters the first wastewater 911 to form high-concentration fluorine wastewater 922 and low-concentration fluorine wastewater 921. The capacitive deionization device 92 is respectively connected to the low-concentration collection tank 60 and the high-concentration collection tank 30. The capacitive deionization device 92 may be a CDI (Capacitive De-Ionization) or a membrane capacitive deionization device (Membrane Capacitive Deionization: MCDI). Although this embodiment is a membrane capacitive deionization device, it is not limited thereto. The capacitive deionization device 92 has a plurality of electrodes. When an external voltage is applied between the plurality of electrodes, an electrostatic field is formed. When the first wastewater 911 enters the electrostatic field, the charged ions in the first wastewater 911 are affected by the Coulomb force and move toward the corresponding electrodes with opposite charges. That is, the anions in the first wastewater 911 move toward the positively charged electrodes, and the cations in the first wastewater 911 move toward the negatively charged electrodes, thereby removing most of the charged ions in the first wastewater 911 and desalting the first wastewater 911. After the adsorption is completed, it is directly removed and desorbed by applying an external voltage, and the anions and cations adsorbed by the electrostatic field are released back into the first wastewater 911. The capacitive deionization device 92 further includes an exchange membrane added on the plurality of electrodes. This exchange membrane is an anion and cation exchange membrane. This exchange membrane blocks the adsorption of co-ions, effectively enhances the desalination performance, prevents the charged ions from adsorbing to the plurality of electrodes when desorbing, completely releases the charged ions adsorbed on the plurality of electrodes, protects the plurality of electrodes, and can reduce the redox reaction occurring on the plurality of electrodes. As can be seen from this, the need for pretreatment of the capacitive deionization device 92 is low, the equipment maintenance is simple, and it has advantages such as low energy consumption and high recovery rate. In this embodiment, the first wastewater 911 enters the capacitive deionization device 92, and the fluoride ions and hydrogen ions in the first wastewater 911 move toward the corresponding electrodes with opposite charges under the electrostatic field, forming the first wastewater 911 into low-concentration fluorine wastewater 921.In one embodiment, the fluoride ion concentration in the low-concentration fluoride wastewater 921 is 50 mg / L. After a certain period of time, an external voltage is applied to desorb and release fluoride ions and hydrogen ions from a plurality of electrodes, forming the first wastewater 911 into high-concentration fluoride wastewater 922. In one embodiment, the fluoride ion concentration in the high-concentration fluoride wastewater 922 is 10,000 mg / L. The low-concentration fluoride wastewater 921 and the high-concentration fluoride wastewater 922 go to different devices respectively. The low-concentration fluoride wastewater 921 is accommodated by the low-concentration collection tank 60, while the high-concentration fluoride wastewater 922 is accommodated by the high-concentration collection tank 30.

[0019] Refer to FIGS. 1 and 2. As shown in FIGS. 1 and 2, the low-concentration collection tank 60 collects the low-concentration fluorine-containing wastewater 921. The low-concentration collection tank 60 is connected to the filtration device 80. The filtration device 80 may be connected to the low-concentration collection tank 60 alone, or may be connected to the wastewater collection tank 90, or may be connected to both the low-concentration collection tank 60 and the wastewater collection tank 90, but is not limited thereto. One or more filtration devices 80 may be connected to increase the total recovery rate or the purity of the produced water. The method of connecting multiple filtration devices may be a multi-stage method to increase the total recovery rate or a multi-pass method to increase the purity of the produced water. The filtration device 80 may be a reverse osmosis (RO) device or a thin-film capacitive deionization device. In this embodiment, the filtration device 80 is a reverse osmosis device. After the low-concentration fluorine-containing wastewater 921 flows toward the filtration device 80, recovered water 801 and second wastewater 802 are formed. The reverse osmosis device selects a semi-permeable membrane pore size of 0.0001 to 0.001 μm and applies pressure. The semi-permeable membrane pore size in this embodiment is 0.001 μm, and recovered water 801 that almost completely removes impurities other than water molecules can be obtained. The impurities may be, for example, metal ions, soluble salts, inorganic molecules, minerals, organic substances, etc. The fluoride ion concentration in the recovered water 801 is less than 5 mg / L in one embodiment. The recovered water 801 is returned to the factory and reused internally to achieve water reuse. Here, the recovered water 801 may enter the second filtration device 80 again, and the plurality of filtration devices 80 can increase the water recovery rate and desalination rate of the recovered water 801, but is not limited thereto. The second wastewater 802 is wastewater that does not pass through the filtration device 80. The second wastewater 802 may be selected to return to the wastewater collection tank 90 or the low-concentration collection tank 60 for recovery.

[0020] Refer to FIGS. 1 to 3. As shown in FIGS. 1 to 3, the high-concentration collection tank 30 collects high-concentration fluorine-containing wastewater 922. The high-concentration collection tank 30 is connected to the reaction device 10. The reaction device 10 is connected to the dehydration device 50. The reaction device 10 and the dehydration device 50 may be the same device or different devices. In this embodiment, they are different devices, but it is not limited thereto. Refer to FIGS. 3 and 4 together. As shown in FIGS. 3 and 4, the present invention further describes in more detail the technical means adopted to achieve a predetermined invention purpose. One end of one of the reaction devices 10 of this embodiment is further specifically connected to the sodium aluminate chemical tank 20, and the sodium aluminate chemical tank 20 adds a compound containing aluminum.

[0021] Refer to FIG. 3. As shown in FIG. 3, in this embodiment, the sodium aluminate chemical tank 20 has a liquid level gauge 21 and a discharge valve 26. The batch quantitative control section 201 of the sodium aluminate chemical tank 20 has a transfer pump 22. Two ball valves 23, 24 are respectively provided between the transfer pump 22 and the sodium aluminate chemical tank 20 and between the transfer pump 22 and the reaction device 10. The batch quantitative control section 201 is provided with a sodium aluminate flow meter 25 at a location adjacent to the reaction device 10. The liquid level gauge 21, the transfer pump 22, the two ball valves 23, 24, the sodium aluminate flow meter 25, and the discharge valve 26 are electrically controlled by the control processor A.

[0022] Refer to Fig. 3. As shown in Fig. 3, the reaction device 10 has a top tank opening 11 and a bottom outlet 12 corresponding to each other. Inside the reaction device 10, there are a dispersion plate 13 having a plurality of liquid holes 131 and a control plate 14 located on the dispersion plate 13 and having a plurality of through holes 141. Inside the reaction device 10, an upper dosing space 101 and a lower reaction space 102 are formed by the dispersion plate 13 and the control plate 14 installed at intervals. The upper dosing space 101 has a sodium aluminate liquid level gauge 15. The lower reaction space 102 communicates with a discharge control section 16 through the bottom outlet 12. The sodium aluminate liquid level gauge 15 and the discharge control section 16 are electrically controlled by a control processor A. In this embodiment, the lower reaction space 102 of the reaction device 10 has a hydrofluoric acid liquid level gauge 17 electrically controlled by a control processor A. In order to detect the liquid level height of the high-concentration fluorine wastewater 922 in the lower reaction space 102, the control processor A electrically controls the flow rates of the sodium aluminum-containing compound and the high-concentration fluorine wastewater 922 output by the sodium aluminate chemical tank 20 and the high-concentration collection tank 30 based on the sodium aluminate liquid level gauge 15 and the hydrofluoric acid liquid level gauge 17. The discharge control section 16 of the reaction device 10 in this embodiment has a flow control valve 161 and a ball valve 162. A discharge flow path 18 is provided between the flow control valve 161 and the bottom outlet 12 of the reaction device 10. The discharge flow path 18 is controlled by a ball valve 181, and the flow control valve 161 and the ball valve 162 of the discharge control section 16 and the ball valve 181 of the discharge flow path 18 are electrically controlled by a control processor A.

[0023] Refer to Fig. 3. As shown in Fig. 3, the dehydration device 50 is electrically controlled by a control processor A and communicates with the discharge control section 16 of the reaction device 10.

[0024] Refer to FIG. 3. As shown in FIG. 3, after the high-concentration collection tank 30 collects a certain amount of high-concentration fluorine wastewater 922, the high-concentration fluorine wastewater 922 is moved into the reaction device 10. The high-concentration collection tank 30 outputs the high-concentration fluorine wastewater 922 into the lower reaction space 102 of the reaction device 10 through a batch quantitative control section 301 that is electrically controlled by the control processor A. In this embodiment, the high-concentration collection tank 30 has a liquid level gauge 31 and a discharge valve 36. The batch quantitative control section 301 of the high-concentration collection tank 30 has a transfer pump 32. Two ball valves 33, 34 are respectively provided between the transfer pump 32 and the high-concentration collection tank 30, and between the transfer pump 32 and the reaction device 10. The batch quantitative control section 301 is provided with a hydrofluoric acid flow meter 35 at a location adjacent to the reaction device 10, and electrically controls the liquid level gauge 31, the transfer pump 32, the two ball valves 33, 34, the hydrofluoric acid flow meter 35, and the discharge valve 36 by the control processor A. In this embodiment, when the high-concentration collection tank 30 collects fluorine ions at a concentration higher than 10,000 mg / L in the high-concentration fluorine wastewater 922, the high-concentration fluorine wastewater 922 is moved to the reaction device 10, but it is not limited to this, and it can also be changed according to the needs of the user. By connecting the reaction device 10 and the sodium aluminate chemical tank 20, the sodium aluminate chemical tank 20 electrically controls a batch quantitative control section 201 by the control processor A and outputs a sodium aluminum compound into the upper dosing space 101 of the reaction device 10. The sodium aluminum compound is specifically sodium aluminate. The fluorine ions and fluorine-containing compounds in the high-concentration fluorine wastewater 922 are mixed with the sodium aluminum compound to form a mixed water sample. The mixed water sample reacts to form cryolite 103 (Na 3 AlF 6) and generate a third waste water 501 (refer to the following formula (I)). The dehydration device 50 separates the precipitated cryolite 103 and the third waste water 501, and allows the third waste water 501 to enter the waste liquid tank 81 or a conventional waste water treatment system. The dehydration device 50 is connected to the waste liquid tank 81. The waste liquid tank 81 is electrically controlled by the control processor A and collects the third waste water 501 discharged from the dehydration device 50. In this embodiment, a ball valve 811 for controlling the flow rate of the third waste water 501 is provided between the waste liquid tank 81 and the dehydration device 50. The waste liquid tank 81 has a liquid level gauge 812, a discharge valve 813, and a low-concentration fluorine waste water output section 814. The low-concentration fluorine waste water output section 814 has a transport pump 815 and two ball valves 816, 817. One ball valve 816 is provided between the transport pump 815 and the waste liquid tank 81, and the other ball valve 817 is provided at the discharge end of the transport pump 815 connected to the low-concentration fluorine waste water output section 814. The liquid level gauge 812, the discharge valve 813, the transport pump 815, and the three ball valves 811, 816, 817 are electrically controlled by the control processor A. Therefore, in order to provide a source of sodium ions and aluminum ions that form the crystals of cryolite 103 provided by the aluminum-sodium-containing compound, the high-concentration fluorine waste water 922 is advantageous for the environment in which the crystallization of cryolite 103 takes place.

[0025]

Chemical formula

[0026] Refer to FIGS. 3 and 4. As shown in FIGS. 3 and 4, the pH value / fluoride ion detection section 40 of the present embodiment has a pH meter 41 and a fluorometer 42 that are electrically controlled by a control processor A. The pH meter 41 and the fluorometer 42 communicate with each other through a pipeline. The pH meter 41 has a first flow path 43 that communicates with the bottom of the lower reaction space 102 of the reactor 10. The first flow path 43 has a measurement pump 431. Two ball valves 433, 434 are respectively provided between the measurement pump 431 and the reactor 10 and between the measurement pump 431 and the pH meter 41. In the present embodiment, a clean water input section 46 is provided between the measurement pump 431 and the pH meter 41. The clean water input section 46 has a flow rate control valve 461 for controlling the amount of clean water input, and controls the amount of clean water to be injected in advance, and detects the pH value and fluoride ion content of the mixed water sample through the pH meter 41 and the fluorometer 42. If the detection is completed and the result is unqualified, the second flow path 44 that communicates the fluorometer 42 and the top of the lower reaction space 102 is used, and the reflux control valve 441 of the second flow path 44 is used to control the mixed water sample after detection to reflux into the reactor 10, or if the result is qualified, through the third flow path 45 that communicates from the fluorometer 42 to the dehydration device 50, the discharge control valve 451 and the ball valve 452 of the third flow path 45 are used to discharge the mixed water sample to the dehydration device 50. The dehydration device 50 communicates with the third flow path 45 of the pH value / fluoride ion detection section 40 and discharges the waste liquid after the pH value / fluoride ion detection section 40 is washed. The end opening of the second flow path 44 that communicates with the inside of the reactor 10 is provided from the upper tank wall of the lower reaction space 102 of the reactor 10 to the upper tank center of the lower reaction space 102. Preferably, the second flow path 44 extends to the upper center of the lower reaction space 102 through the pipe body 442 and communicates, so that the influence generated when the mixed water sample returns can be minimized.

[0027] Refer to FIG. 3. As shown in FIG. 3, in order to ensure the measurement accuracy of the pH meter 41 and the fluorometer 42, the pH value / fluoride ion detection section 40 utilizes the clean water input section 46 to wash the pH meter 41 and the fluorometer 42 with the input clean water, and then discharges them to the dehydration device 50 through the third flow path 45. The measurement pump 431, the two flow rate control valves 432, 461, the three ball valves 433, 434, 452, and the discharge control valve 451 of the pH value / fluoride ion detection section 40 are electrically controlled by the control processor A. The equipment of the present invention further communicates with the second flow path 44 and the discharge control section 16 through the fourth flow path 48. By installing the seed crystal storage tank 47 and the transport pump 481 in the fourth flow path 48, when the mixed water sample refluxes from the discharge control section 16 to the second flow path 44 through the fourth flow path 48 and enters the reaction device 10, the seed crystal can be introduced into the reaction device 10 through the seed crystal storage tank 47, completing the transplantation step, promoting the crystal reaction to increase the crystal particle size dimension, and improving the crystal quality of cryolite 103.

[0028] Refer to FIGS. 5 to 9. As shown in FIGS. 5 to 9, in the present invention, the dispersion disk 13 and the control disk 14 in the reaction device 10 are formed in a disk shape. The plurality of liquid holes 131 of the dispersion disk 13 are formed in a cross-shaped radial pattern from the center of the circle. The plurality of through holes 141 of the control disk 14 are composed of a first through hole group 14a, a second through hole group 14b, and a third through hole group 14c. The first through hole group 14a, the second through hole group 14b, and the third through hole group 14c are formed in a cross-shaped radial pattern from the center of the circle of the control disk 14, and an angle θ is formed between adjacent radial directions. The first through hole group 14a has the same number of through holes 141 as the liquid holes 131 of the dispersion disk 13. The numbers of the second through hole group 14b and the third through hole group 14c are less than the number of the liquid holes 131 of the dispersion disk 13 and have different numbers of through holes 141.

[0029] In this embodiment, the distribution plate 13 further has a plurality of positioning holes 132. The control plate 14 has three sets of position restraint holes 142 corresponding to the positions and numbers of the positioning holes 132 of the distribution plate 13. An angle θ is formed between each set of position restraint holes 142. One set of position restraint holes 142 of the control plate 14 is aligned with the positioning holes 132 of the distribution plate 13, and a plurality of positioning pins (not shown) corresponding to the number of the positioning holes 132 are inserted into the positioning holes 132 of the distribution plate 13 and the position restraint holes 142 of the control plate 14, so as to align and fix the positions of the liquid holes 131 of the distribution plate 13 and the through holes 141 of the control plate 14, and ensure the flow rate and liquid flow pattern of the sodium aluminum-containing compound.

[0030] Other features and advantages of the present invention will be clearly understood from the following detailed description in conjunction with FIGS. 1 and 2.

[0031] In this embodiment, the wastewater collection tank 90 and the activated carbon filtration device 91 are connected. In advance, the hydrofluoric acid wastewater 901 is collected and stored in the wastewater collection tank 90. The fluoride ion concentration in the hydrofluoric acid wastewater 901 is 1000 mg / L. The hydrofluoric acid wastewater 901 is flowed into the activated carbon filtration device 91, and by the adsorption action of the activated carbon in the activated carbon filtration device 91, the soluble or hardly decomposable organic substances, chlorine gas, odor, etc. contained in the hydrofluoric acid wastewater 901 are adsorbed and removed. The adsorption of chlorine gas can cause problems such as oxidation or organic scale in the subsequent capacitive deionization device 92 or the filtration device 80, and it is filtered by the activated carbon filtration device 91 to form the first wastewater 911. The activated carbon filtration device 91 is connected to the capacitive deionization device 92, and the first wastewater 911 is flowed into the capacitive deionization device 92. By electrochemical and physical adsorption actions, the ions in the solution of the first wastewater 911 are rapidly adsorbed to form low-concentration fluoride wastewater 921. The fluoride ion concentration in the low-concentration fluoride wastewater 921 is 50 mg / L. When the electric field is removed, the ions adsorbed on the electrode surface are desorbed to form high-concentration fluoride wastewater 922. The fluoride ion concentration in the high-concentration fluoride wastewater 922 is 10000 mg / L. The capacitive deionization device 92 is respectively connected to the high-concentration collection tank 30 and the low-concentration collection tank 60. The low-concentration fluoride wastewater 921 flows towards the low-concentration collection tank 60, and the high-concentration fluoride wastewater 922 flows towards the high-concentration collection tank 30. The low-concentration collection tank 60 is connected to the filtration device 80. The filtration device 80 is connected to the wastewater collection tank 90. The low-concentration fluoride wastewater 921 flows towards the filtration device 80, and through the pore size of the semipermeable membrane, the osmotic characteristics of water molecules, and pressurization, the second wastewater 802 and the recovered water 801 with good water quality that can be directly discharged or recovered and reused are obtained. The second wastewater 802 can be refluxed to the wastewater collection tank 90. The high-concentration collection tank 30 is connected to the reaction device 10. The reaction device 10 is connected to the dehydration device 50. The high-concentration fluoride wastewater 922 flows towards the reaction device 10. The sodium aluminate chemical agent tank 20 adds a sodium aluminum-containing compound to the reaction device 10. The sodium aluminum-containing compound is sodium aluminate (NaAlO with a concentration of about 35 - 45 wt% in this embodiment. 2)It is an aqueous solution. Based on the concentration of hydrofluoric acid in the high-concentration fluorine wastewater 922, referring to the ratio of formula (I), a sodium aluminum-containing compound is added. Since the high-concentration fluorine wastewater 922 in the reaction device 10 has sufficient fluoride ions, the sodium ions and aluminum ions of sodium aluminate undergo a chemical reaction. The high-concentration fluorine wastewater 922 is mixed with the sodium aluminum-containing compound to form a mixed water sample. The mixed water sample is detected and monitored by the pH value / fluoride ion detection section 40. After confirming that the reaction is complete, cryolite 103 and other similar precipitates are produced, and then, through the dehydration device 50 and the waste liquid tank 81, the cryolite 103 and the third wastewater 501 are separated, and cryolite 103 with uniform particle size and high purity is obtained. The cryolite 103 may be used as industrial raw materials such as chemical raw materials, fluxes for glass and ceramic manufacturing, fluxes for aluminum electrolysis manufacturing processes, wear-resistant additives for abrasive products, wear-resistant fillers for resins or rubbers, fluxes for the steel industry, electrolytes for the production of ferroalloy boiling steel, and building material additives. Here, after the reaction, the temperature of the reaction device 10 is decreased, and the temperature of the third wastewater 501 is lowered to 40 °C or lower, but it is not limited to this only.

[0032] As can be seen from the above, the hydrogen fluoride acid wastewater recovery system capable of extracting industrial raw materials according to the present invention initially purifies the hydrogen fluoride acid wastewater 901 by the activated carbon filtration device 91, and then applies the capacitive deionization device 92 to desalt the first wastewater 911. In addition to concentrating and recovering fluoride ions in the first wastewater 911, the electrodes are regenerated by the discharge of the capacitive deionization device 92. Separately, there is no need to add chemicals or adjust the pH value. Moreover, due to the adsorption and desorption of the electrodes and the presence of the exchange membrane, the ions desorbed from the electrodes are prevented from being adsorbed onto the opposite electrodes to form colloids and scales, so that it can be used repeatedly. In order to separate the low-concentration fluoride wastewater 921 and the high-concentration fluoride wastewater 922 by applying or removing a voltage, subsequent treatment can be conveniently carried out. The high-concentration fluoride wastewater 922 is introduced into the reaction device 10, and a sodium aluminum-containing compound is added through the sodium aluminate chemical tank 20 for reaction to form the precipitation of cryolite 103, an industrial raw material with economic value. The low-concentration fluoride wastewater 921 is filtered through the filtration device 80 to obtain the recovered water 801 with good water quality that can be refluxed to the factory for use. The present invention has a preferable removal efficiency of fluoride ions in the hydrogen fluoride acid wastewater 901, and can obtain cryolite 103, an industrial raw material, and the recovered water 801 that can be recovered and reused, thereby obtaining the effects of environmental protection and reducing the cost of wastewater treatment.

[0033] As described above, the connection relationship between the devices of this system equipment and their valves, and the assembly relationship of the dispersion plate 13 and the control panel 14 have been mainly described. Hereinafter, as shown in FIGS. 3 to 10, a plurality of devices such as valves, liquid level gauges, flow meters, pumps, pH meters, and fluorometers of the present invention are electrically connected to the control processor A and form a control method that is electrically controlled by the control processor A. This control method may be automatic or manual and includes the following steps (S1) to (S6).

[0034] Step (S1): Parameter setting The control processor A sets the parameter items and their numerical ranges shown in Table 1. However, the parameter items are not limited to only the items shown in Table 1, and the parameter settings may be increased or decreased according to the actual operation requirements. After the parameter setting step of step (S1) is completed, the dispersion plate 13 and the control panel 14 are installed according to the necessity of the flow rate of the sodium aluminum-containing compound, and the flow rate at which the sodium aluminum-containing compound falls into the lower reaction space 102 is controlled.

[0035]

Table 1

[0036] Step (S2): Injection of high-concentration fluorine wastewater The batch quantitative control section 301 of the high-concentration collection tank 30 is activated, and the high-concentration fluorine wastewater 922 is input into the lower reaction space 102 of the reactor 10 based on the set value of the parameter setting step (S1).

[0037] Step (S3): Addition of sodium aluminum-containing compound After the high-concentration fluorine wastewater 922 is completely injected into the reactor 10, the batch quantitative control section 201 of the sodium aluminate chemical tank 20 is activated, and the sodium aluminum-containing compound is input into the upper dosing space 101 of the reactor 10 based on the set value of the parameter setting step (S1). In this step, in a preferred implementation state of the batch quantitative control section 201 of the sodium aluminate chemical tank 20, when starting up, simultaneously based on the set value of the parameter setting step (S1), the timing of the input time of the sodium aluminum-containing compound is started and recorded.

[0038] Step (S4): Standing the mixed water sample Based on the set value of the parameter setting step (S1), the calculation of the reaction standing time is started. In this step, preferably, after the sodium aluminum-containing compound is batch output from the sodium aluminate chemical tank 20, the timing is started and standing is carried out when the low liquid level of the liquid level gauge 21 is reached.

[0039] Step (S5): Supply the mixed water sample to the pH value / fluoride ion detection section When the reaction standing timekeeping ends, start the measurement pump 431 and the flow control valve 432 of the pH value / fluoride ion detection section 40, and introduce the mixed water sample in the reaction device 10 into the pH value / fluoride ion detection section 40. This step further includes simultaneously proceeding with the pH value and fluoride ion concentration reading step (S51) of the high-concentration fluoride wastewater 922 and the mixed water sample, and the step (S52) of refluxing the mixed water sample to the reaction device. That is, the mixed water sample flows through the pH meter 41 and the fluorometer 42, reads the pH value and the fluoride ion concentration, and at the same time, is controlled by the valve, enters the fourth flow path 48 through the discharge control section 16 from the bottom outlet 12 of the reaction device 10, flows through the seed crystal storage tank 47, and introduces the seed crystal into the reaction device 10 through the second flow path 44.

[0040] Step (S6): Determine the reaction end point Use the read pH value and fluoride ion concentration of the mixed water sample to determine the reaction end point. When the reaction has not reached the reaction end point, execute the pH value / fluoride ion detection section closing step (S61) and the fine adjustment step (S62) of the sodium aluminum-containing compound. Based on the parameters set in the parameter setting step (S1), input a trace amount of the sodium aluminum-containing compound into the reaction device 10 with the read pH value, and until the reaction reaches the reaction end point, repeat the steps of inputting the sodium aluminum-containing compound (S3), standing the mixed water sample (S4), supplying the mixed water sample to the pH value / fluoride ion detection section (S5), and determining the reaction end point (S6). The pH value and the addition amount of the sodium aluminum-containing compound in the fine adjustment step (S62) of the sodium aluminum-containing compound are determined like the corresponding values in Table 2, but are not limited to this, and the corresponding values may be adjusted according to the actual operation.

[0041]

Table 2

[0042] Step (S7): Solid-liquid separation Start the dehydration device 50 and the discharge control section 16 of the reaction device 10 to perform the discharge step. More specifically, when the reaction reaches the reaction end point, after starting the dehydration device 50 and the discharge control section 16 of the reaction device 10, perform the crystal dehydration collection step (S71) and the third wastewater discharge step (S72). After completion, execute the discharge control section closing step (S73) of the reaction device. In this step, preferably before performing the crystal dehydration collection step (S71), the dehydration device 50 obtains a predetermined rotation speed, allows cryolite 103 to flow into the dehydration device 50 by gravity, and the shaken third wastewater 501 concentrates and flows into the waste liquid tank 81 by gravity, completing the third wastewater discharge step (S72). The cryolite 103 remains in the filter cloth of the dehydration device 50, completing the crystal dehydration collection step (S71), and finally closing the discharge control section 16 of the reaction device 10.

[0043] Step (S8): Automatic mode judgment The control processor A pre-sets the current operation to the automatic mode or the manual mode. In the case of the automatic mode, the control processor A performs automatic control, starting from the high-concentration fluorine wastewater injection step (S2), and repeats the above steps. In the case of the manual mode, the control processor A stops the automatic control, returns to the parameter setting step (S1), and after completing the parameter setting, starts the automatic control.

[0044] According to the present invention described above, when the fluoride ion concentration flowing into the high-concentration fluoride wastewater 922 is 10 to 500 g / L, the standing time is 10 to 200 minutes, and the pH value at the end of the reaction is 2 to 10, the fluoride ion concentration in the third wastewater 501 flowing out after the reaction drops to 20 g / L or less, and the fluoride content contained in the third wastewater 501 can be effectively removed. In the following Table (3), five examples are listed to explain the operation control parameters and related analysis data of the equipment for producing cryolite 103 from the high-concentration fluoride wastewater 922 of the present invention.

[0045]

Table 3

[0046] By means of the dispersion plate 13 and the control plate 14 in the reaction device 10 described above, the liquid flow pattern and flow rate of the contact reaction between the aluminum-sodium-containing compound and the high-concentration fluoride wastewater 922 are controlled, and the pH value / fluoride ion detection section 40 in which the loop form communicates with the reaction device 10 monitors the pH value and fluoride ion concentration of the high-concentration fluoride wastewater 922 and the mixed water sample, effectively controls the factors affecting the crystal purity of cryolite 103 during the reaction process, enables the system to stably form the crystal purity of cryolite 103 for recycling and reuse, increases the recovery rate of fluoride ions, improves the crystal purity of the produced cryolite 103, and has high economic efficiency.

[0047] As can be understood by those skilled in the art of this field, although the preferred embodiments of the present invention have been disclosed as described above, these do not limit the present invention in any way. Various changes and modifications can be made without departing from the gist and scope of the present invention. Therefore, the scope of the claims of the present invention should be broadly interpreted to include such changes and modifications.

Explanation of Reference Numerals

[0048] 10 Reaction device 11 Top tank opening 12 Bottom outlet 13 Dispersion plate 14 Control plate 14a First through-hole group 14b Second through-hole group 14c Third through-hole group 15 Sodium aluminate liquid level gauge 16 Discharge control section 17 Hydrofluoric acid liquid level gauge 18 Discharge flow path 20 Sodium aluminate chemical tank 21 Liquid level gauge 22 Transfer pump 23 Ball valve 24 Ball valve 25 Sodium aluminate flow meter 26 Discharge valve 30 High-concentration collection tank 31 Liquid level gauge 32 Transfer pump 33 Ball valve 34 Ball valve 35 Hydrofluoric acid flow meter 36 Discharge valve 40 pH value / fluoride ion detection section 41 pH meter 42 Fluorometer 43 First flow path 44 Second flow path 45 Third flow path 46 Clean water input section 47 Seed crystal storage tank 48 Fourth flow path 50 Dewatering device 60 Low-concentration collection tank 70 Overflow prevention base 71 Overflow prevention body 72 Leak detection device 73 Drain valve 80 Filtration device 81 Waste liquid tank 90 Waste water collection tank 91 Activated carbon filtration device 92 Capacitive deionization device 101 Upper dosing space 102 Lower reaction space 103 Cryolite 131 Liquid hole 132 Positioning hole 141 Through hole 142 Position restraint hole 161 Flow control valve 162 Ball valve 181 Ball valve 201 Batch metering control section 301 Batch metering control section 431 Measuring pump 432 Flow control valve 433 Ball valve 434 Ball valve 441 Reflux control valve 442 Pipe body 451 Discharge control valve 452 Ball valve 461 Flow control valve 481 Transfer pump 501 Third waste water 801 Recovered water 802 Second waste water 811 Ball valve 812 Liquid level gauge 813 Discharge valve 814 Low-concentration fluorine waste water output section 815 Transfer pump 816 Ball valve 817 Ball valve 901 Hydrofluoric acid waste water 911 First waste water 921 Low-concentration fluorine waste water 922 High-concentration fluorine waste water A Control processor

Claims

1. A hydrofluoric acid wastewater recovery system capable of extracting industrial raw materials, comprising a wastewater collection tank, an activated carbon filtration device, a capacitive deionization device, a low-concentration collection tank, at least one filtration device, a high-concentration collection tank, a reaction device, and a dehydration device, The wastewater collection tank contains hydrofluoric acid wastewater, the activated carbon filter is connected to the wastewater collection tank and filters the hydrofluoric acid wastewater to generate a first wastewater; the capacitive deionizer is in communication with the activated carbon filter and has a plurality of oppositely charged electrodes; migrate ions in the first wastewater toward a plurality of corresponding electrodes of opposite charge to form a low-fluoride wastewater; By desorbing and releasing ions from multiple electrodes, high-concentration fluoride wastewater is formed. the low-concentration collection tank is connected to the capacitive deionization device and stores low-concentration fluoride wastewater; the filtering device is connected to the low-concentration collecting tank and filters the low-concentration fluorine wastewater to form recovered water, which is returned to the plant for internal reuse; the high-concentration collection tank is connected to the capacitive deionization device and stores the high-concentration fluoride wastewater; The reaction device is connected to the high-concentration collection tank, and produces cryolite and a third wastewater by reacting the added aluminum sodium-containing compound with the high-concentration fluorine wastewater; A hydrofluoric acid wastewater recovery system capable of extracting industrial raw materials, characterized in that the dehydration device is connected to the reaction device and separates the cryolite and the third wastewater.

2. The capacitive deionization device is a CDI (Capacitive De-Ionization) or thin film capacitive deionization device; 2. The hydrofluoric acid wastewater recovery system capable of extracting industrial raw materials according to claim 1, wherein the aluminum sodium-containing compound is sodium aluminate.

3. the ions in the first wastewater include fluorine ions and hydrogen ions; the fluorine ion concentration in the high-concentration fluorine wastewater is higher than the fluorine ion concentration in the low-concentration fluorine wastewater, 2. The hydrofluoric acid wastewater recovery system capable of extracting industrial raw materials according to claim 1, wherein the fluorine ion concentration in the high-concentration fluorine wastewater is higher than the fluoride ion concentration in the hydrofluoric acid wastewater.

4. The filtration device is connected to the wastewater collection tank, to the low-concentration collection tank, or to both the low-concentration collection tank and the wastewater collection tank; 2. The hydrofluoric acid wastewater recovery system for extracting industrial raw materials according to claim 1, wherein the filtration device is a reverse osmosis (RO) device or a thin film capacitive deionization device.

5. Further comprising a control processor; The reactor has a top vessel inlet and a bottom outlet corresponding to each other, The reactor includes a distributor having a plurality of liquid holes and a control panel located on the distributor and having a plurality of through holes. The reactor includes a distributor and a control panel spaced apart from each other, and an upper dosing space and a lower reaction space are formed inside the reactor. The upper dosage space has a sodium aluminate level gauge; The lower reaction space communicates with the discharge control section through the bottom outlet, and discharges a mixed water sample formed by the aluminum sodium-containing compound and the high-concentration fluorine wastewater; reacting the mixed water sample to produce the cryolite and the third wastewater; the sodium aluminate level gauge and the discharge control section are electronically controlled by the control processor; the discharge control section is connected to the dehydrator and the waste liquid tank to separate the cryolite and the third waste water; the dehydrator and the waste liquid tank are electrically controlled by the control processor; the dehydrator is in communication with the discharge control section of the reactor; 2. The hydrofluoric acid wastewater recovery system capable of extracting industrial raw materials according to claim 1, wherein the waste liquid tank collects the third wastewater discharged from the dehydration device.

6. the lower reaction space of the reactor has a hydrofluoric acid level gauge electrically controlled by the control processor; the discharge control section of the reactor includes a flow control valve and a ball valve; a discharge passage is provided between the flow control valve and the bottom outlet of the reactor; The discharge passage is controlled by the ball valve, the flow control valve and the ball valve of the discharge control section and the ball valve of the discharge flow path are electrically controlled by the control processor; Further comprising a sodium aluminate drug tank and a pH value / fluoride ion detection section; The sodium aluminate chemical tank is electrically controlled by the control processor through a batch quantity control section, and the sodium aluminate chemical compound is added into the upper dosage space of the reactor; the pH value / fluoride ion detection section includes a pH meter and a fluorometer electrically controlled by the control processor in communication with each other, supplies the mixed water sample to the pH meter and the fluorometer, and detects the pH value and fluoride content of the mixed water sample discharged by the discharge control section; the pH meter has a first flow path communicating with a bottom of the lower reaction space of the reactor; The hydrofluoric acid wastewater recovery system capable of extracting industrial raw materials according to claim 5, characterized in that the fluorometer has a second flow path communicating with the top of the lower reaction space, and the mixed water sample is returned to the reaction device or discharged.

7. The plurality of liquid holes of the dispersion plate are formed in a U-shape radially from a center of a circle, the plurality of through holes of the control panel are composed of a first through hole group, a second through hole group, and a third through hole group, the first through hole group, the second through hole group, and the third through hole group are formed in a U-shape radially from the center of the control panel, and an angle is formed between adjacent radial directions, the first through-hole group has the same number of through-holes as the liquid holes of the distribution plate, The second through hole group and the third through hole group have a number of through holes that is smaller than and different from the number of the liquid holes of the distribution plate, The distributor has a plurality of positioning holes, The control panel has three sets of position restraint holes corresponding to the positions and number of the positioning holes of the distribution panel, and an angle is formed between the position restraint holes of each set, The pair of position restraining holes of the control panel and the positioning holes of the distribution panel are positionable, 6. The hydrofluoric acid wastewater recovery system capable of extracting industrial raw materials according to claim 5, wherein the distribution board and the control board are fixed by inserting a plurality of positioning pins, the number of which corresponds to the number of the positioning holes.

8. The high-concentration collection tank has a level gauge and a discharge valve, the batch quantity control section of the high concentration collection tank includes a transfer pump; Two ball valves are provided between the transport pump and the high-concentration collection tank and between the transport pump and the reaction device, respectively; the batch quantitative control section of the high-concentration collection tank is provided with a hydrofluoric acid flow meter adjacent to the reactor; In the high-concentration collection tank, the level gauge, the transfer pump, the two ball valves, the hydrofluoric acid flow meter, and the discharge valve are electrically controlled by the control processor; The sodium aluminate chemical tank has a level gauge and a discharge valve, The sodium aluminate chemical tank batch metering control section has a transfer pump; Two ball valves are provided between the transport pump and the sodium aluminate chemical tank and between the transport pump and the reaction device, respectively; The batch quantitative control section of the sodium aluminate chemical tank is provided with a sodium aluminate flow meter adjacent to the reactor; In the sodium aluminate chemical tank, the level gauge, the transport pump, the two ball valves, the sodium aluminate flow meter, and the discharge valve are electrically controlled by the control processor; the first flow path of the pH value / fluoride ion detection section has a measuring pump; A flow control valve and a ball valve are provided between the reaction device and the measurement pump; a ball valve and a clean water input section are provided between the measuring pump and the pH meter; the clean water input section having a flow control valve for controlling the amount of clean water input; the second flow path has a reflux control valve; the fluorometer having a third flow path; the third flow path has a discharge control valve and a ball valve to control discharge of the waste liquid; In the pH value / fluoride ion detection section, the measuring pump, the two flow control valves, the three ball valves, and the discharge control valve are electrically controlled by the control processor; an end opening of the second flow path communicating with the inside of the reaction device is provided from an upper tank wall of a lower reaction space of the reaction device to a center portion of the upper tank of the lower reaction space; the waste liquid tank has a level gauge, a discharge valve, and a low-concentration fluorine wastewater output section; a ball valve for controlling a flow rate of the third wastewater is provided between the waste liquid tank and the dehydration device; the low-concentration fluorine wastewater output section has a transport pump and two ball valves, one of which is provided between the transport pump and the waste liquid tank and the other of which is provided at a discharge end of the transport pump connected to the wastewater output section, 7. The hydrofluoric acid wastewater recovery system capable of extracting industrial raw materials according to claim 6, wherein in the waste liquid tank, the level gauge, the discharge valve, the transport pump, and the three ball valves are electrically controlled by the control processor.

9. The hydrofluoric acid wastewater recovery system capable of extracting industrial raw materials according to claim 6 is installed on an overflow prevention base, An overflow prevention body is provided around the periphery of the overflow prevention base, and the overflow prevention body has a leak detection device electrically controlled by the control processor and a drain valve provided at the bottom of the overflow prevention base, Further comprising a seed crystal reservoir; The seed crystal storage tank stores seed crystals therein and is installed in the fourth flow path; The fourth flow path communicates with the reactor and the exhaust control section thereof, A transport pump is installed between the seed crystal storage tank and the discharge control section; The hydrofluoric acid wastewater recovery system capable of extracting industrial raw materials according to claim 6, characterized in that the fourth flow path guides the mixed water sample discharged by the discharge control section to the seed crystal storage tank and then returns it to the reactor, and introduces the seed crystals into the reactor.

10. The control processor executes a control method including a parameter setting step, a high-concentration fluorine wastewater injection step, an aluminum sodium-containing compound addition step, a step of allowing the mixed water sample to stand, a step of supplying the mixed water sample to the pH value / fluoride ion detection section, a step of determining a reaction end point, and a step of solid-liquid separation; In the parameter setting step, the control processor sets parameter items and numerical ranges of the parameter items, and installs the distributor and the control panel according to the flow rate needs of the aluminum sodium-containing compound to control the flow rate of the aluminum sodium-containing compound falling into the lower reaction space; In the high-concentration fluorine wastewater injection step, a batch quantitative control section of the high-concentration collection tank is started, and the high-concentration fluorine wastewater is injected into the lower reaction space of the reaction device based on the set value in the parameter setting step; In the aluminum sodium-containing compound addition step, after the high-concentration fluorine wastewater is completely injected into the reactor, the batch quantitative control section of the sodium aluminate drug tank is started, and the aluminum sodium-containing compound is added into the upper drug space of the reactor according to the set value of the parameter setting step, to form the mixed water sample; In the step of allowing the mixed water sample to stand, a calculation of a reaction standing time is started based on the set values ​​in the parameter setting step; In the step of supplying the mixed water sample to the pH value / fluoride ion detection section, when the reaction static time is completed, the pH value / fluoride ion detection section is started, the mixed water sample in the reaction device is supplied to the pH value / fluoride ion detection section, the pH value and the fluoride ion concentration of the mixed water sample are read, and the mixed water sample is returned to the reaction device; In the reaction end point determination step, the control processor determines the reaction end point based on the pH value and fluoride ion concentration of the mixed water sample that have been read, and when the reaction has not reached the reaction end point, performs a pH value / fluoride ion detection section closing step and an aluminum sodium-containing compound fine adjustment step, and adds a small amount of aluminum sodium-containing compound to the reaction device based on the parameters set in the parameter setting step and the read pH value, and repeats the steps of adding aluminum sodium-containing compound, leaving the mixed water sample undisturbed, supplying the mixed water sample to the pH value / fluoride ion detection section, and determining the reaction end point until the reaction reaches the reaction end point, The hydrofluoric acid wastewater recovery system capable of extracting industrial raw materials according to claim 9, characterized in that in the solid-liquid separation step, when the reaction reaches the reaction end point, the discharge control section of the reactor is started, and then the crystallization dehydration collection step and the third wastewater discharge step are carried out, and after completion, the discharge control section of the reactor is closed.

11. The control method further includes an automatic mode determination step; said control processor pre-setting the current operation to an automatic mode or a manual mode; If in automatic mode, automatically control the control processor to start from the step of injecting high-concentration fluoride wastewater and repeat the steps described above; 11. The hydrofluoric acid wastewater recovery system capable of extracting industrial raw materials according to claim 10, characterized in that, when in the manual mode, the control processor stops the automatic control and returns to the parameter setting step, and starts the automatic control after the parameter setting is completed.

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