An atmospheric pollution treatment device and a process for recovering valuable components from waste cathode carbon blocks

Abstract

This invention provides an air pollution control device and a process for recovering valuable components from waste cathode carbon blocks. Relating to the field of air pollution control, the air pollution control device includes a dust removal mechanism installed on the ground. The air pollution control device provided by this invention removes solid impurities from hydrogen fluoride flue gas via centrifugation in a dust removal tank, effectively preventing blockage of subsequent equipment. The hydrogen fluoride gas is cooled by contacting a spiral tube through a central cylinder, ensuring safe operation while achieving the recycling of cooling water, saving energy and water. The cooled hydrogen fluoride gas is then sprayed counter-currently with calcium hydroxide solution drawn from a circulating pump in a treatment tank, generating calcium fluoride precipitate through chemical absorption, achieving compliant emissions and recovering fluorine resources. A replenishment pump draws calcium hydroxide solution from inside the replenishment tank to replenish the circulating tank, maintaining the stability of the reaction system. This achieves efficient purification and resource utilization of high-temperature hydrogen fluoride flue gas generated from calcining aluminum hydroxyl fluoride.

Description

Technical Field

[0001] This invention relates to the field of air pollution control, and in particular to an air pollution control device and a process for recovering valuable components from waste cathode carbon blocks. Background Technology

[0002] In the aluminum electrolysis industry, cathode carbon blocks are a key component, generating a large amount of waste after long-term use. These waste cathode carbon blocks not only occupy a large amount of land resources, but also contain toxic and harmful substances such as fluorides. If not properly handled, they can cause serious pollution to the soil, water bodies, and atmospheric environment, endangering the ecological balance and human health. Aluminum fluoride products are obtained by calcining the recovered components, but this also releases a large amount of hydrogen fluoride gas that needs to be treated. In order to cope with the severe air pollution situation, my country has introduced strict emission limits for flue gas. Currently, hydrogen fluoride gas is treated by introducing it into air pollution control devices to meet emission standards.

[0003] Existing air pollution control devices first perform dust removal treatment when treating hydrogen fluoride gas generated by calcination, then input the hydrogen fluoride gas into the treatment tank, spray calcium hydroxide solution for gas-liquid adsorption, and the adsorbed gas is discharged from the top of the tower.

[0004] However, when existing air pollution control devices treat hydrogen fluoride gas produced by calcination, the hydrogen fluoride gas still has a high temperature. When it directly enters the treatment tank for gas-liquid adsorption, the absorption efficiency drops sharply and the adsorption reaction is prevented from continuing.

[0005] Therefore, it is necessary to provide an air pollution control device and a process for recovering valuable components from waste cathode carbon blocks to solve the above-mentioned technical problems. Summary of the Invention

[0006] This invention provides an air pollution control device and a process for recovering valuable components from waste cathode carbon blocks, which solves the problem that when high-temperature hydrogen fluoride gas is directly introduced into the treatment tank for gas-liquid adsorption, the absorption efficiency drops sharply and the adsorption reaction is prevented from continuing.

[0007] To solve the above-mentioned technical problems, the present invention provides an air pollution control device, comprising: a dust removal mechanism installed on the ground, the dust removal mechanism including: a dust removal tank and a cooling box; the dust removal tank is installed on the ground by a support; an air inlet is connected to one side of the dust removal tank; a dust collection box is connected to the bottom end of the dust removal tank; a central cylinder is connected to the top of the inner wall of the dust removal tank; the top of the central cylinder penetrates the top of the inner wall of the dust removal tank and extends to the outside; an air outlet pipe is connected to the end of the central cylinder located outside the dust removal tank; and the cooling box is installed on the ground. A cooling water pump is fixedly installed on the top of the cooling tank. The input end of the cooling water pump is connected to the inside of the cooling tank through a connecting pipe. The output end of the cooling water pump is connected to a water delivery pipe. The top end of the water delivery pipe passes through one side of the dust collector and one side of the central cylinder and extends into the inside of the central cylinder. The top end of the water delivery pipe is connected to a spiral pipe. The top end of the spiral pipe is connected to a return water pipe. The end of the return water pipe passes through the inner wall of the central cylinder and extends to the outside. The end of the return water pipe is connected to the top of the cooling tank.

[0008] The processing unit is used to process hydrogen fluoride gas after dust removal and cooling.

[0009] A circulation mechanism is used to circulate sprayed calcium hydroxide liquid;

[0010] A replenishment mechanism for replenishing the interior of the processing unit with liquid calcium hydroxide.

[0011] Preferably, the processing mechanism is located on the ground. The processing mechanism includes a circulation box, which is located on the ground. The top of the circulation box is connected to a processing tank via a connecting funnel. The top of the processing tank is connected to an outlet, and the end of the vent pipe is connected to one side of the processing tank.

[0012] Preferably, the circulation mechanism is located on the ground. The circulation mechanism includes a circulation pump, which is located on the ground. The input end of the circulation pump is connected to a water pumping pipe. One end of the water pumping pipe passes through one side of the circulation tank and extends into the interior. The output end of the circulation pump is connected to a lift pipe. One side of the lift pipe is connected to two branch pipes. One end of each of the two branch pipes passes through one side of the treatment tank and extends into the interior. Both of the branch pipes are connected to a spray pipe.

[0013] Preferably, the tonic mechanism is located on the ground. The tonic mechanism includes a tonic tank, which is located on the ground. A tonic pump is fixedly installed on the top of the tonic tank. The input end of the tonic pump is connected to the inside of the tonic tank through a connecting pipe, and the output end of the tonic pump is connected to the top of the circulation tank through a tonic pipe.

[0014] Preferably, a collecting funnel is fixedly installed on the inner wall of the connecting funnel, a switch is fixedly installed on the top of the connecting funnel, two swirling plates are fixedly installed on the inner wall of the treatment tank, the two swirling plates are respectively adapted to the two spray pipes, a column-stopping mechanism is fixedly installed on the top of the inner wall of the circulation tank, the column-stopping mechanism includes fixed columns, two fixed columns are fixedly installed on the top of the inner wall of the circulation tank, a base plate is fixedly installed at the bottom of the two fixed columns, and several column-stopping posts are fixedly installed on the top of the base plate.

[0015] Preferably, a filtering mechanism is fixedly installed on the top of the connecting funnel. The filtering mechanism includes buffer components. Two buffer components are fixedly installed on the top of the connecting funnel. A filter box is fixedly installed on the top of the two buffer components. The bottom of the filter box has a plurality of filter holes. The plurality of filter holes are adapted to and installed with a plurality of abutments. The bottom of the filter box has a transverse groove. An annular baffle is fixedly installed on the inner wall of the filter box through two connecting plates. The collecting funnel is adapted to and installed with the filter box.

[0016] Preferably, a scraper mechanism is fixedly installed at the bottom of the filter box. The scraper mechanism includes a motor, which is fixedly installed at the bottom of the filter box via a bracket. The output shaft of the motor passes through the bottom of the filter box and extends into the interior of the filter box. A scraper is fixedly installed at the end of the motor output shaft, and the scraper is adapted to the transverse groove.

[0017] Preferably, a recycling mechanism is fixedly installed on the top of the substrate. The recycling mechanism includes a recycling box, which is fixedly installed on the top of the substrate. A triangular block is fixedly installed inside the recycling box. Two recycling pipes are connected to the bottom of the recycling box. The ends of the two recycling pipes penetrate the inner wall of the circulation box and extend to the outside. The ends of the two recycling pipes are connected to a transfer box. The recycling box is adapted to the transverse groove.

[0018] Preferably, the top of the outlet is connected to an adsorption demisting mechanism via an exhaust pipe. The adsorption demisting mechanism includes an adsorption demisting box, one side of which is connected to the end of the exhaust pipe. Several demisting plates and activated carbon boxes are fixedly installed inside the adsorption demisting box.

[0019] A process for recovering valuable components from waste cathode carbon blocks includes the following steps:

[0020] S1: Waste cathode carbon blocks are crushed, ground, and sieved, and then dried after sieving.

[0021] S2: Mix the waste cathode carbon block with deionized water, and then transfer the mixture to a constant temperature water bath for reaction. Separate the solid and liquid to obtain filter residue A and filtrate A.

[0022] S3: Mix filter residue A with concentrated sulfuric acid solution and add potassium permanganate to the mixture. After mixing, transfer the mixture to a constant temperature water bath for reaction. Add deionized water to continue the reaction and ripen the mixture.

[0023] S4: The mixture is ultrasonically exfoliated and centrifuged to obtain graphene oxide filter residue and a mixture containing... , , Plasma acid leaching solution;

[0024] S5: The graphene oxide filter residue is washed with deionized water and dried to obtain graphene oxide. The washing liquid is collected and recycled.

[0025] S6: Mix the filtrate A produced in S2, the acid leaching solution in S4, and the water washing solution in S5, and then pass the mixture through a manganese-based ion sieve for selective adsorption. The lithium-rich solution was obtained by analyzing the concentrated hydrogen chloride solution, which was then concentrated, crystallized, and dried to obtain the lithium chloride product.

[0026] S7: After lithium extraction, sodium hydroxide is added to the mother liquor and transferred to a constant temperature water bath for reaction. Solid-liquid separation is performed to obtain filter residue B and filtrate B, whose main components are aluminum hydroxy fluoride. Filter residue B is dried and calcined to obtain aluminum fluoride product.

[0027] S8: Sodium hydroxide is added to filtrate B for adjustment, and the mixture is transferred to a constant temperature water bath for reaction. After filtration, filter residue C and filtrate C, which contain calcium hydroxide and aluminum hydroxide, are obtained. Filter residue C can be used for wastewater purification after drying. Potassium, sodium and manganese salts are recovered from filtrate C by staged freeze crystallization.

[0028] Compared with related technologies, the air pollution control device provided by the present invention has the following beneficial effects:

[0029] This invention provides an air pollution control device. Hydrogen fluoride flue gas is centrifuged in a dust collector to remove solid impurities, effectively preventing blockage of subsequent equipment. The hydrogen fluoride gas is cooled by contacting a spiral tube through a central cylinder, ensuring safe operation while achieving the recycling of cooling water, thus saving energy and water. The cooled hydrogen fluoride gas is then sprayed counter-currently with calcium hydroxide solution drawn from a circulating pump in the treatment tank. Through chemical absorption, calcium fluoride precipitate is generated, achieving compliant emissions and recovering fluorine resources. A replenishment pump draws calcium hydroxide solution from the replenishment tank to replenish the circulating tank, maintaining the stability of the reaction system. This invention achieves efficient purification and resource utilization of high-temperature hydrogen fluoride flue gas generated from calcining aluminum hydroxy fluoride. Attached Figure Description

[0030] Figure 1 A schematic diagram of a preferred embodiment of an air pollution control device provided by the present invention;

[0031] Figure 2 Another structural schematic diagram of a preferred embodiment of an air pollution control device;

[0032] Figure 3 for Figure 1 The diagram shows the structure of the dust removal mechanism.

[0033] Figure 4 for Figure 1 The diagram shows the structure of the processing mechanism.

[0034] Figure 5 for Figure 1 The diagram shows the structure of the circulating mechanism.

[0035] Figure 6 for Figure 2 The diagram shown is a structural schematic of the tonic mechanism.

[0036] Figure 7 This is a schematic diagram of the structure of a second embodiment of an air pollution control device;

[0037] Figure 8 This is another structural schematic diagram of a second embodiment of an air pollution control device;

[0038] Figure 9 for Figure 7 The diagram shows the installation of the recycling mechanism;

[0039] Figure 10 for Figure 9 The diagram shows the installation of the filter mechanism;

[0040] Figure 11 for Figure 10 The diagram shows the structure of the anti-pillar mechanism.

[0041] Figure 12 for Figure 10 The diagram shows the structure of the scraper mechanism.

[0042] Figure 13 for Figure 12 The diagram shown is a structural schematic of the filtration mechanism.

[0043] Figure 14 for Figure 10 The diagram shown illustrates the structure of the recycling mechanism.

[0044] Figure 15 for Figure 8 The diagram shown is a schematic of the adsorption and demisting mechanism.

[0045] Figure 16 This is a process flow diagram of a process for recovering valuable components from waste cathode carbon blocks.

[0046] Numbered in the diagram: 1. Processing mechanism, 101. Processing tank, 102. Connecting funnel, 103. Circulation box, 104. Discharge port; 2. Dust removal mechanism, 201. Air inlet, 202. Dust collector, 203. Dust collection box, 204. Central cylinder, 205. Air outlet pipe, 206. Cooling box, 207. Cooling water pump, 208. Water supply pipe, 209. Spiral pipe, 210. Return water pipe; 3. Circulation mechanism, 301. Water suction pipe, 302. Circulation pump, 303. Lifting pipe, 304. Branch pipe, 305. Spray pipe; 4. Chemical replenishment mechanism, 401. Chemical replenishment tank, 402. Chemical replenishment pump, 403. Chemical replenishment tube. 5. Pipe, 501. Support column mechanism, 502. Base plate, 503. Support column, 6. Filtering mechanism, 601. Filter box, 602. Filter hole, 603. Buffer, 604. Horizontal groove, 605. Connecting plate, 606. Annular baffle, 7. Scraper mechanism, 701. Motor, 702. Scraper, 8. Recycling mechanism, 801. Recycling box, 802. Triangular block, 803. Recycling pipe, 804. Transfer box, 9. Adsorption and demisting mechanism, 901. Adsorption and demisting box, 902. Demisting plate, 903. Activated carbon box, 10. Collection funnel, 11. Switch, 12. Swirl plate, 13. Exhaust pipe. Detailed Implementation

[0047] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0048] First Embodiment

[0049] Please refer to the following: Figures 1-6An air pollution control device includes: a dust removal mechanism 2 installed on the ground, the dust removal mechanism 2 including: a dust collection tank 202 and a cooling box 206. The dust collection tank 202 is installed on the ground by a support. An air inlet 201 is connected to one side of the dust collection tank 202. A dust collection box 203 is connected to the bottom end of the dust collection tank 202. A central cylinder 204 is connected to the top of the inner wall of the dust collection tank 202. The top of the central cylinder 204 penetrates the top of the inner wall of the dust collection tank 202 and extends to the outside. An air outlet pipe 205 is connected to the end of the central cylinder 204 located outside the dust collection tank 202. The cooling box 206 is installed on the ground. A cooling water pump 207 is fixedly installed in the unit. The input end of the cooling water pump 207 is connected to the inside of the cooling tank 206 through a connecting pipe. The output end of the cooling water pump 207 is connected to a water supply pipe 208. The top end of the water supply pipe 208 passes through one side of the dust collector 202 and one side of the central cylinder 204 and extends into the inside of the central cylinder 204. The top end of the water supply pipe 208 is connected to a spiral pipe 209. The top end of the spiral pipe 209 is connected to a return water pipe 210. The end of the return water pipe 210 passes through the inner wall of the central cylinder 204 and extends to the outside. The end of the return water pipe 210 is connected to the top of the cooling tank 206.

[0050] Processing unit 1, the processing unit 1 is used to process hydrogen fluoride gas after dust removal and cooling;

[0051] Circulation mechanism 3, which is used to circulate sprayed calcium hydroxide liquid;

[0052] The replenishment mechanism 4 is used to replenish the interior of the processing unit 1 with calcium hydroxide liquid.

[0053] The processing mechanism 1 is located on the ground. The processing mechanism 1 includes a circulation box 103. The circulation box 103 is located on the ground. The top of the circulation box 103 is connected to a processing tank 101 via a connecting funnel 102. The top of the processing tank 101 is connected to an outlet 104. The end of the vent pipe 205 is connected to one side of the processing tank 101.

[0054] The circulation mechanism 3 is located on the ground. The circulation mechanism 3 includes a circulation pump 302. The circulation pump 302 is located on the ground. The input end of the circulation pump 302 is connected to a water pumping pipe 301. One end of the water pumping pipe 301 passes through one side of the circulation tank 103 and extends into the interior. The output end of the circulation pump 302 is connected to a lift pipe 303. One side of the lift pipe 303 is connected to two branch pipes 304. One end of each of the two branch pipes 304 passes through one side of the treatment tank 101 and extends into the interior. Each of the two branch pipes 304 is connected to a spray pipe 305.

[0055] The tonic mechanism 4 is located on the ground. The tonic mechanism 4 includes a tonic tank 401. The tonic tank 401 is located on the ground. A tonic pump 402 is fixedly installed on the top of the tonic tank 401. The input end of the tonic pump 402 is connected to the inside of the tonic tank 401 through a connecting pipe. The output end of the tonic pump 402 is connected to the top of the circulation tank 103 through a tonic pipe 403.

[0056] In actual use, the openings of the two spray pipes 305 face downwards; the spiral pipe 209 is a gradually expanding spiral pipe.

[0057] The working principle of the air pollution control device provided by this invention is as follows:

[0058] First, the hydrogen fluoride flue gas generated from calcining aluminum hydroxy fluoride is introduced into the dust collector 202 through the air inlet 201. After entering the dust collector 202, the hydrogen fluoride flue gas undergoes centrifugal action to precipitate solid impurities, which fall off from the inner wall of the dust collector 202 and enter the dust collection box 203. The dust-removed hydrogen fluoride gas rises from the bottom of the central cylinder 204. The cooling water pump 207 is started to draw cooling water from the cooling box 206 and deliver it to the spiral tube 209 through the water supply pipe 208. The high-temperature dust-removed hydrogen fluoride gas undergoes heat exchange and cooling through the spiral tube 209. After absorbing heat, the cooling water is sent back to the cooling box 206 through the return water pipe 210 and is cooled and recycled again inside the cooling box 206.

[0059] Then, the cooled hydrogen fluoride gas is discharged from the outlet pipe 205 into the interior of the treatment tank 101. The circulation pump 302 is started to draw calcium hydroxide solution from the circulation tank 103 through the water pumping pipe 301. The solution is then transported through the riser pipe 303 to the two branch pipes 304 and finally sprayed downwards by the two spray pipes 305. The upward hydrogen fluoride gas comes into contact with the calcium hydroxide solution and undergoes an adsorption reaction to defluorinate, producing calcium fluoride precipitate. The defluorinated gas is discharged from the outlet 104.

[0060] Finally, when the concentration and level of the calcium hydroxide solution in the circulation tank 103 decrease, the replenishment pump 402 is started to draw calcium hydroxide solution from the replenishment tank 401 and replenish the circulation tank 103 with new calcium hydroxide solution through the replenishment pipe 403.

[0061] Compared with related technologies, the air pollution control device provided by the present invention has the following beneficial effects:

[0062] Hydrogen fluoride flue gas is centrifuged in dust collector 202 to remove solid impurities, effectively preventing blockage of subsequent equipment. The hydrogen fluoride gas is cooled by contacting spiral tube 209 through central cylinder 204, ensuring safe operation while realizing the recycling of cooling water, saving energy and water. The cooled hydrogen fluoride gas is sprayed counter-currently with calcium hydroxide solution drawn by circulation pump 302 in treatment tank 101, generating calcium fluoride precipitate through chemical absorption, achieving standard emission of flue gas and recovering fluorine resources. The calcium hydroxide solution in replenishment tank 401 is drawn by replenishment pump 402 to replenish circulation tank 103, maintaining the stability of the reaction system, and realizing the efficient purification and resource utilization of high-temperature hydrogen fluoride flue gas generated by calcining aluminum hydroxy fluoride.

[0063] Second Embodiment

[0064] Please refer to the following: Figures 7-15 Based on the air pollution control device provided in the first embodiment of this application, the second embodiment of this application proposes another air pollution control device. The second embodiment is merely a preferred embodiment of the first embodiment, and the implementation of the second embodiment will not affect the separate implementation of the first embodiment.

[0065] Specifically, the second embodiment of this application provides an air pollution control device that differs in that a collection funnel 10 is fixedly installed on the inner wall of the connecting funnel 102, a switch 11 is fixedly installed on the top of the connecting funnel 102, two swirl plates 12 are fixedly installed on the inner wall of the treatment tank 101, the two swirl plates 12 are respectively adapted to the two spray pipes 305, a stop mechanism 5 is fixedly installed on the top of the inner wall of the circulation box 103, the stop mechanism 5 includes a fixed column 501, both fixed columns 501 are fixedly installed on the top of the inner wall of the circulation box 103, a base plate 502 is fixedly installed at the bottom of the two fixed columns 501, and a plurality of stop columns 503 are fixedly installed on the top of the base plate 502.

[0066] A filter mechanism 6 is fixedly installed on the top of the connecting funnel 102. The filter mechanism 6 includes a buffer member 603. Two buffer members 603 are fixedly installed on the top of the connecting funnel 102. A filter box 601 is fixedly installed on the top of the two buffer members 603. A plurality of filter holes 602 are opened at the bottom of the filter box 601. The plurality of filter holes 602 are adapted to and installed with a plurality of abutment posts 503. A transverse groove 604 is opened at the bottom of the filter box 601. An annular baffle 606 is fixedly installed on the inner wall of the filter box 601 through two connecting plates 605. The collecting funnel 10 is adapted to and installed with the filter box 601.

[0067] A scraper mechanism 7 is fixedly installed at the bottom of the filter box 601. The scraper mechanism 7 includes a motor 701. The motor 701 is fixedly installed at the bottom of the filter box 601 by a bracket. The output shaft of the motor 701 passes through the bottom of the filter box 601 and extends into the interior of the filter box 601. A scraper 702 is fixedly installed at the end of the output shaft of the motor 701. The scraper 702 is adapted to the transverse groove 604.

[0068] A recycling mechanism 8 is fixedly installed on the top of the substrate 502. The recycling mechanism 8 includes a recycling box 801, which is fixedly installed on the top of the substrate 502. A triangular block 802 is fixedly installed inside the recycling box 801. Two recycling pipes 803 are connected to the bottom of the recycling box 801. The ends of the two recycling pipes 803 penetrate the inner wall of the circulation box 103 and extend to the outside. The ends of the two recycling pipes 803 are connected to a transfer box 804. The recycling box 801 is adapted to the transverse groove 604.

[0069] The top of the outlet 104 is connected to an adsorption demisting mechanism 9 via an exhaust pipe 13. The adsorption demisting mechanism 9 includes an adsorption demisting box 901. One side of the adsorption demisting box 901 is connected to the end of the exhaust pipe 13. Several demisting plates 902 and activated carbon boxes 903 are fixedly installed inside the adsorption demisting box 901.

[0070] In actual use, the activated carbon box 903 is filled with high-efficiency activated carbon; the buffer 603 is a guide post with a built-in spring. When the filter box 601 increases in weight due to the accumulation of calcium fluoride precipitation, the spring is slowly compressed, which plays a role in buffering the descent. When the weight exceeds the set threshold, the spring is fully compressed to a rigid state and touches the bottom, and the filter box 601 descends directly to the lowest position; the two connecting plates 605 do not contact the collecting funnel 10 after descent; the collecting funnel 10 does not detach from the filter box 601 after descent.

[0071] The working principle of the air pollution control device provided in this embodiment is as follows:

[0072] First, the hydrogen fluoride gas enters the interior of the treatment tank 101 and flows through two swirl plates 12 in sequence, then comes into contact with the calcium hydroxide solution. The sprayed calcium hydroxide solution enters the interior of the filter box 601 from the collection funnel 10.

[0073] Then, when hydrogen fluoride gas is introduced into the treatment tank 101, it comes into contact with the sprayed calcium hydroxide solution. The hydrogen fluoride gas and calcium hydroxide form calcium fluoride precipitate. The defluorinated gas is discharged from the exhaust pipe 13 into the adsorption demister 901. The defluorinated gas first passes through the demister plate 902 to remove water vapor, and then passes through the activated carbon box 903 to adsorb the accompanying organic impurities or odors.

[0074] Then, the generated calcium fluoride precipitate falls into the interior of the filter box 601, and the calcium hydroxide solution flows back to the interior of the circulation tank 103 through the filter holes 602. The calcium fluoride precipitate is trapped inside the filter box 601. As the defluorination process progresses, the amount of calcium fluoride precipitate increases, which also indicates that the concentration of the calcium hydroxide solution is decreasing. Gravity causes the filter box 601 to descend and be buffered by two buffers 603. As the filter box 601 descends, several filter holes 602 come into contact with several abutments 503. The abutments 503 are inserted into the interior of the filter holes 602 to remove the attached impurities that clog the filter holes 602. At the same time, after the filter box 601 descends, it contacts the switch 11, shutting off the circulation pump 302 and turning on the replenishment pump 402. The descending filter box 601 also causes the annular baffle 606 to descend. The annular baffle 606 descends directly to the air outlet pipe 205, temporarily sealing the air inlet passage.

[0075] Then, the motor 701 is started to drive the scraper 702 to rotate, which discharges the calcium fluoride precipitate inside the filter box 601 from the transverse groove 604. The abutment 503 is inserted into the filter hole 602, so the scraper 702 achieves a thorough cleaning without discharging the calcium fluoride precipitate into the lower circulation box 103, thus avoiding clogging the pipeline and reducing the reaction efficiency. At this time, the recovery box 801 is also inserted into the transverse groove 604 of the lowered filter box 601. The calcium fluoride precipitate is discharged from the transverse groove 604 into the interior of the recovery box 801, and then diverted by the triangular block 802 to be discharged from the two recovery pipes 803 into the transfer box 804 for recycling.

[0076] Finally, after the calcium fluoride precipitate is discharged, the filter box 601 automatically resets due to the reduced weight, the circulation pump 302 starts to perform normal defluorination again, and the air intake passage is opened at the same time.

[0077] Compared with related technologies, the air pollution control device provided in this embodiment has the following beneficial effects:

[0078] After hydrogen fluoride gas reacts fully with calcium hydroxide solution via cyclone plate 12, the defluorinated gas passes sequentially through demister plate 902 and activated carbon box 903 for water vapor removal and deep purification, ensuring final emission compliance. The calcium fluoride precipitate generated during the reaction is trapped in filter box 601. As the precipitate accumulates and the weight of filter box 601 increases, it automatically descends. This is achieved by inserting a stop post 503 into the filter holes 602 for physical unblocking, and simultaneously triggering switch 11 to stop circulation pump 302 and start replenishment pump 402 to maintain calcium hydroxide solution concentration. At the same time, annular baffle 606 closes the air intake passage to prevent untreated gas from escaping into treatment tank 101. Then, motor 701 drives... The moving scraper 702 discharges the increased calcium fluoride precipitate from the transverse trough 604 into the recovery box 801 and then into the transfer box 804. The abutment column 503 is inserted into the filter hole 602, so the scraper 702 achieves comprehensive cleaning without discharging the precipitate into the lower circulation box 103, avoiding pipeline blockage and reducing reaction efficiency. After the filter box 601 is lightened, it automatically resets and resumes circulation spraying and air intake. The whole set of actions does not require manual intervention. It couples filter hole anti-clogging, chemical replenishment control, air intake lock and precipitate recovery into the same mechanical feedback chain, which significantly reduces the frequency of manual maintenance and operational risks, ensures the stability of defluorination efficiency, and realizes the resource recovery of calcium fluoride precipitate.

[0079] A process for recovering valuable components from waste cathode carbon blocks includes the following steps:

[0080] S1: The waste cathode carbon blocks generated during the aluminum electrolysis process are crushed by a jaw crusher and ground by a planetary ball mill and sieved through a certain mesh. The sieved waste cathode carbon blocks are then dried at a certain temperature for a period of time for later use.

[0081] S2: Weigh a certain amount of dried waste cathode carbon block and mix it with deionized water in a certain solid-liquid ratio. After mixing, transfer it to a constant temperature water bath and react it at a certain temperature and a certain stirring speed for a period of time to remove soluble salts. Solid-liquid separation yields filter residue A and filtrate A.

[0082] S3: Mix filter residue A with a certain mass fraction of concentrated sulfuric acid in a certain solid-liquid ratio, and add potassium permanganate to the mixture in a certain mass ratio. After mixing evenly, transfer it to a constant temperature water bath and react at 40℃-55℃ with a certain stirring speed for 60min-90min to achieve graphite interlayer oxidation expansion. After the reaction is completed, add deionized water to the filter residue in a certain solid-liquid ratio and raise the temperature to 90℃-95℃ to continue the reaction for 60min-90min to mature it and expand the graphite interlayer spacing.

[0083] S4: After the curing reaction is complete, the mixture is subjected to ultrasonic exfoliation, with the ultrasonic power controlled at 300W-450W for 20-35 minutes. Centrifugation yields graphene oxide filter residue and residue containing... , , Plasma acid leaching solution;

[0084] S5: The graphene oxide filter residue is washed with deionized water according to a certain solid-liquid ratio until the pH is neutral. After washing, it is dried at a certain temperature for a period of time to obtain graphene oxide. The washing liquid is collected and recycled.

[0085] S6: Mix the filtrate A produced in S2, the acid leaching solution in S4, and the water washing solution in S5, and pass the mixture through a manganese ion sieve at a certain flow rate. Selective adsorption After adsorption, a certain concentration of concentrated hydrogen chloride solution is used for desorption to obtain lithium-rich solution, which is then concentrated, crystallized, and dried to obtain lithium chloride product.

[0086] S7: Add sodium hydroxide to the mother liquor after lithium extraction to adjust the pH to 5.5-6.0, transfer it to a constant temperature water bath and react it at a certain temperature and stirring speed for a period of time. The solid and liquid are separated to obtain filter residue B and filtrate B, which are mainly composed of aluminum hydroxy fluoride. Filter residue B is dried and calcined to obtain aluminum fluoride product.

[0087] S8: Add sodium hydroxide to filtrate B to adjust the pH to 10.5-12.5, transfer it to a constant temperature water bath and react it at a certain temperature and stirring speed for a period of time. Filter to obtain filter residue C and filtrate C, which are composed of calcium hydroxide and aluminum hydroxide. Filter residue C can be used for wastewater purification after drying. Filtrate C recovers potassium, sodium and manganese salts by graded freeze crystallization.

[0088] First Embodiment

[0089] Step S1: The waste cathode carbon blocks generated during the aluminum electrolysis process are crushed by a jaw crusher and ground by a planetary ball mill and sieved through a 200-mesh sieve. The sieved waste cathode carbon blocks are then dried at 100°C for 8 hours for later use.

[0090] Step S2: Weigh 500g of dried waste cathode carbon block and mix it with deionized water at a solid-liquid ratio of 1:3. After mixing, transfer the mixture to a constant temperature water bath and react at 60℃ with a stirring speed of 350rpm for 90min to remove soluble salts. The solid and liquid are separated to obtain filter residue A and filtrate A.

[0091] Step S3: Mix filter residue A with 90% sulfuric acid concentrate at a solid-liquid ratio of 1:5, and add potassium permanganate to the mixture at a mass ratio of 4:1. After mixing evenly, transfer the mixture to a constant temperature water bath and react at 40°C with a stirring speed of 350 rpm for 60 minutes to achieve graphite interlayer oxidation expansion. After the reaction is completed, add deionized water to the filter residue at a solid-liquid ratio of 1:5 and raise the temperature to 90°C to continue the reaction for 90 minutes to mature the graphite interlayer spacing.

[0092] Step S4: After the ripening reaction is complete, the mixture is ultrasonically exfoliated at a power of 300W for 20 minutes. Centrifugation yields graphene oxide filter residue and residue containing... , , Plasma acid leaching solution.

[0093] Step S5: Add deionized water to the graphene oxide filter residue at a solid-liquid ratio of 1:3 and wash until the pH is neutral. After washing, dry at 80℃ for 6 hours to obtain graphene oxide. Collect and recover the washing liquid.

[0094] Step S6: Mix the filtrate A produced in step S2, the acid leaching solution from step S4, and the water washing solution from step S5, and pass the mixture through a manganese ion sieve at a flow rate of 8 mL / min. Selective adsorption After adsorption, a 1 mol / L concentrated hydrogen chloride solution was used for desorption to obtain a lithium-rich solution, which was then concentrated, crystallized, and dried to obtain the lithium chloride product.

[0095] Step S7: Add sodium hydroxide to the mother liquor after lithium extraction to adjust the pH to 6.0, transfer it to a constant temperature water bath and react at 60°C with a stirring speed of 350 rpm for 2 hours. After solid-liquid separation, filter residue B and filtrate B, whose main components are aluminum hydroxy fluoride, are obtained. Filter residue B is dried and calcined to obtain aluminum fluoride product.

[0096] Step S8: Add sodium hydroxide to filtrate B to adjust the pH to 12, transfer to a constant temperature water bath and react at 60°C with a stirring speed of 350 rpm for 2 hours. Filter to obtain filter residue C and filtrate C, which are composed of calcium hydroxide and aluminum hydroxide. Filter residue C can be used for wastewater purification after drying. Filtrate C recovers potassium, sodium and manganese salts by fractional freezing crystallization.

[0097] Second Embodiment

[0098] Step S1: The waste cathode carbon blocks generated during the aluminum electrolysis process are crushed by a jaw crusher and ground by a planetary ball mill and sieved through a 150-mesh sieve. The sieved waste cathode carbon blocks are then dried at 100°C for 8 hours for later use.

[0099] Step S2: Weigh 1000g of dried waste cathode carbon block and mix it with deionized water at a solid-liquid ratio of 1:3. After mixing, transfer the mixture to a constant temperature water bath and react at 68℃ with a stirring speed of 350rpm for 90min to remove soluble salts. Separate the solid and liquid to obtain filter residue A and filtrate A.

[0100] Step S3: Mix filter residue A with 95% sulfuric acid concentrate at a solid-liquid ratio of 1:6, and add potassium permanganate to the mixture at a mass ratio of 5:1. After mixing evenly, transfer the mixture to a constant temperature water bath and react at 30°C with a stirring speed of 350 rpm for 90 minutes to achieve graphite interlayer oxidation expansion. After the reaction is completed, add deionized water to the filter residue at a solid-liquid ratio of 1:5 and raise the temperature to 90°C to continue the reaction for 90 minutes to mature the graphite interlayer spacing.

[0101] Step S4: After the ripening reaction is complete, the mixture is ultrasonically exfoliated at a power of 350W for 25 minutes. Centrifugation yields graphene oxide filter residue and residue containing... , , Plasma acid leaching solution.

[0102] Step S5: Add deionized water to the graphene oxide filter residue at a solid-liquid ratio of 1:3 and wash until the pH is neutral. After washing, dry at 80℃ for 6 hours to obtain graphene oxide. Collect and recover the washing liquid.

[0103] Step S6: Mix the filtrate A produced in step S2, the acid leaching solution from step S4, and the water washing solution from step S5, and pass the mixture through a manganese ion sieve at a flow rate of 6 mL / min. Selective adsorption After adsorption, a lithium-rich solution was obtained by desorption using a 0.5 mol / L concentrated hydrogen chloride solution, followed by concentration, crystallization, and drying to obtain the lithium chloride product.

[0104] Step S7: Add sodium hydroxide to the mother liquor after lithium extraction to adjust the pH to 5.5, transfer it to a constant temperature water bath and react at 60°C with a stirring speed of 350 rpm for 2 hours. After solid-liquid separation, filter residue B and filtrate B, whose main components are aluminum hydroxyfluoride, are obtained. Filter residue B is dried and calcined to obtain aluminum fluoride product.

[0105] Step S8: Add sodium hydroxide to filtrate B to adjust the pH to 11.5, transfer to a constant temperature water bath and react at 60°C with a stirring speed of 350 rpm for 2 hours. Filter to obtain filter residue C and filtrate C, which are composed of calcium hydroxide and aluminum hydroxide. Filter residue C can be used for wastewater purification after drying. Filtrate C recovers potassium, sodium and manganese salts by graded freeze crystallization.

[0106] Compared with related technologies, the process for recovering valuable components from waste cathode carbon blocks provided by the present invention has the following advantages:

[0107] Through an innovative process, carbon is efficiently recovered from aluminum electrolytic cathode carbon blocks for graphene preparation. At the same time, valuable elements such as sodium, aluminum, fluorine, and lithium are recovered through leaching, improving resource utilization, reducing environmental pollution, and achieving a win-win situation for both economic and environmental benefits.

[0108] The above description is merely an embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural or procedural transformations made based on the content of the present invention's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of the present invention.

Claims

1. An air pollution control device, characterized in that, include: A dust removal mechanism installed on the ground includes a dust collection tank and a cooling box. The dust collection tank is mounted on the ground via a bracket. An air inlet is connected to one side of the dust collection tank, and a dust collection box is connected to the bottom of the dust collection tank. A central cylinder is connected to the top of the inner wall of the dust collection tank. The top of the central cylinder penetrates the top of the inner wall of the dust collection tank and extends to the outside. An air outlet pipe is connected to the end of the central cylinder located outside the dust collection tank. The cooling box is installed on the ground, and a cooling water pump is fixedly installed on the top of the cooling box. The input end of the cooling water pump is connected to the inside of the cooling box via a connecting pipe, and the output end of the cooling water pump is connected to a water delivery pipe. The top end of the water delivery pipe penetrates one side of the dust collection tank and one side of the central cylinder and extends to the inside of the central cylinder. A spiral pipe is connected to the top end of the water delivery pipe, and a return water pipe is connected to the top end of the spiral pipe. The end of the return water pipe penetrates the inner wall of the central cylinder and extends to the outside. The end of the return water pipe is connected to the top of the cooling box. The processing mechanism is used to process hydrogen fluoride gas after dust removal and cooling. A circulation mechanism is used to circulate sprayed calcium hydroxide liquid; A replenishment mechanism for replenishing the interior of the processing unit with liquid calcium hydroxide.

2. The air pollution control device according to claim 1, characterized in that, The processing mechanism is located on the ground and includes a circulation box. The top of the circulation box is connected to a processing tank via a connecting funnel. The top of the processing tank is connected to an outlet, and the end of the vent pipe is connected to one side of the processing tank.

3. The air pollution control device according to claim 2, characterized in that, The circulation mechanism is located on the ground and includes a circulation pump. The circulation pump is located on the ground and its input end is connected to a water pumping pipe. One end of the water pumping pipe passes through one side of the circulation tank and extends into the interior. The output end of the circulation pump is connected to a lift pipe. One side of the lift pipe is connected to two branch pipes. One end of each of the two branch pipes passes through one side of the treatment tank and extends into the interior. Both of the branch pipes are connected to a spray pipe.

4. The air pollution control device according to claim 2, characterized in that, The tonic mechanism is located on the ground and includes a tonic tank. The tonic tank is located on the ground and a tonic pump is fixedly installed on the top of the tonic tank. The input end of the tonic pump is connected to the inside of the tonic tank through a connecting pipe, and the output end of the tonic pump is connected to the top of the circulation tank through a tonic pipe.

5. An air pollution control device according to claim 3, characterized in that, A collecting funnel is fixedly installed on the inner wall of the connecting funnel, and a switch is fixedly installed on the top of the connecting funnel. Two swirling plates are fixedly installed on the inner wall of the treatment tank, and the two swirling plates are respectively adapted to the two spray pipes. A column-stopping mechanism is fixedly installed on the top of the inner wall of the circulation tank. The column-stopping mechanism includes fixed columns. Two fixed columns are fixedly installed on the top of the inner wall of the circulation tank. A base plate is fixedly installed at the bottom of the two fixed columns. Several column-stopping posts are fixedly installed on the top of the base plate.

6. The air pollution control device according to claim 5, characterized in that, A filtration mechanism is fixedly installed on the top of the connecting funnel. The filtration mechanism includes buffer components. Two buffer components are fixedly installed on the top of the connecting funnel. A filter box is fixedly installed on the top of the two buffer components. The bottom of the filter box has a plurality of filter holes, which are adapted to and installed with a plurality of abutments. The bottom of the filter box has a transverse groove. An annular baffle is fixedly installed on the inner wall of the filter box through two connecting plates. The collecting funnel is adapted to and installed with the filter box.

7. An air pollution control device according to claim 6, characterized in that, A scraper mechanism is fixedly installed at the bottom of the filter box. The scraper mechanism includes a motor. The motor is fixedly installed at the bottom of the filter box by a bracket. The output shaft of the motor passes through the bottom of the filter box and extends into the interior of the filter box. A scraper is fixedly installed at the end of the motor output shaft. The scraper is adapted to the transverse groove.

8. An air pollution control device according to claim 6, characterized in that, A recycling mechanism is fixedly installed on the top of the substrate. The recycling mechanism includes a recycling box, which is fixedly installed on the top of the substrate. A triangular block is fixedly installed inside the recycling box. Two recycling pipes are connected to the bottom of the recycling box. The ends of the two recycling pipes penetrate the inner wall of the circulation box and extend to the outside. The ends of the two recycling pipes are connected to a transfer box. The recycling box is adapted to the transverse groove.

9. An air pollution control device according to claim 2, characterized in that, The top of the outlet is connected to an adsorption demisting mechanism via an exhaust pipe. The adsorption demisting mechanism includes an adsorption demisting box, one side of which is connected to the end of the exhaust pipe. Several demisting plates and activated carbon boxes are fixedly installed inside the adsorption demisting box.

10. A process for recovering valuable components from waste cathode carbon blocks, characterized in that, Includes the following steps: S1: Waste cathode carbon blocks are crushed, ground, and sieved, and then dried after sieving. S2: Mix the waste cathode carbon block with deionized water, and then transfer the mixture to a constant temperature water bath for reaction. Separate the solid and liquid to obtain filter residue A and filtrate A. S3: Mix filter residue A with concentrated sulfuric acid solution and add potassium permanganate to the mixture. After mixing, transfer the mixture to a constant temperature water bath for reaction. Add deionized water to continue the reaction and ripen the mixture. S4: The mixture is ultrasonically exfoliated and centrifuged to obtain graphene oxide filter residue and a mixture containing... , , Plasma acid leaching solution; S5: The graphene oxide filter residue is washed with deionized water and dried to obtain graphene oxide. The washing liquid is collected and recycled. S6: Mix the filtrate A produced in S2, the acid leaching solution in S4, and the water washing solution in S5, and then pass the mixture through a manganese-based ion sieve for selective adsorption. The lithium-rich solution was obtained by analyzing the concentrated hydrogen chloride solution, which was then concentrated, crystallized, and dried to obtain the lithium chloride product. S7: After lithium extraction, sodium hydroxide is added to the mother liquor and transferred to a constant temperature water bath for reaction. Solid-liquid separation is performed to obtain filter residue B and filtrate B, whose main components are aluminum hydroxy fluoride. Filter residue B is dried and calcined to obtain aluminum fluoride product. Hydrogen fluoride gas generated during calcination is collected and treated by an air pollution control device as described in any one of claims 1-9 to meet emission standards. S8: Sodium hydroxide is added to filtrate B for adjustment, and the mixture is transferred to a constant temperature water bath for reaction. After filtration, filter residue C and filtrate C, which contain calcium hydroxide and aluminum hydroxide, are obtained. Filter residue C can be used for wastewater purification after drying. Potassium, sodium and manganese salts are recovered from filtrate C by staged freeze crystallization.

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