A method for resource recovery of thallium from desulfurized gypsum and a multi-stage washing and extraction device

Abstract

This invention provides a method for the resource recovery of thallium from desulfurized gypsum and a multi-stage washing and extraction device. The method for resource recovery of thallium from desulfurized gypsum includes the following steps: Step S1: Mixing desulfurized gypsum and an extraction agent in a certain proportion to form a mixture; Step S2: Washing the mixture with water, separating the solid and liquid to obtain a washing liquid and a detoxified residue; Step S3: Recirculating the washing liquid, adding sulfides to the washing liquid with a thallium concentration higher than 20 mg / L, filtering to obtain thallium sulfide; reacting thallium sulfide with dilute nitric acid to obtain thallium nitrate; or reacting thallium sulfide with dilute sulfuric acid to obtain thallium sulfate. This invention provides a method for resource recovery of thallium from desulfurized gypsum and a multi-stage washing and extraction device, which, by adding a reducing agent and using a multi-stage washing process, converts trivalent thallium into more mobile monovalent thallium, thereby achieving efficient and deep removal of thallium and converting desulfurized gypsum into a non-toxic industrial raw material.

Description

Technical Field

[0001] This invention relates to the field of comprehensive resource recycling technology, and in particular to a method for the resource recovery of thallium from desulfurized gypsum and a multi-stage washing and extraction device. Background Technology

[0002] Thallium is a highly toxic heavy metal that often occurs in non-ferrous metal sulfide ores and is released into the atmosphere during the smelting process. Lithium mica is one of the important lithium resources and is the most commonly used mineral raw material for lithium extraction. The sulfate roasting method is currently the most mainstream lithium extraction process, and the main auxiliary material used is expensive potassium sulfate. There is an urgent need to find efficient and economical auxiliary materials to replace potassium sulfate. The calcium and sulfur resources contained in desulfurized gypsum make it a potential substitute for potassium sulfate.

[0003] Traditional methods for removing thallium from flue gas mostly involve washing the flue gas with water to reduce thallium concentration in the water body, which is then treated in conjunction with the desulfurization process. However, this method of flue gas purification makes it difficult to remove thallium deeply, resulting in the desulfurization gypsum produced from the desulfurization process containing a certain concentration of thallium, which becomes hazardous waste that is difficult to sell or dispose of. This significantly increases the production costs of enterprises and wastes the calcium and sulfur resources in the desulfurization gypsum.

[0004] Therefore, it is necessary to provide a resource recovery method for thallium in desulfurized gypsum and a multi-stage washing and extraction device to solve the above-mentioned technical problems. Summary of the Invention

[0005] This invention provides a method for the resource recovery of thallium from desulfurized gypsum and a multi-stage washing and extraction device, which solves the problem that traditional water washing methods cannot completely remove thallium from flue gas, resulting in high concentrations of thallium residue in desulfurized gypsum, which becomes hazardous waste that is difficult to utilize as a resource.

[0006] To solve the above-mentioned technical problems, the present invention provides a method for the resource recovery of thallium in desulfurized gypsum, comprising the following steps;

[0007] Step S1: Mix the desulfurized gypsum and eluent in a certain proportion to prepare a mixture;

[0008] Step S2: The mixture is washed with water, and solid-liquid separation is performed to obtain washing liquid and detoxified residue;

[0009] Step S3: Recycle the washing solution, add sulfide to the washing solution with a thallium concentration higher than 20 mg / L, filter to obtain thallium sulfide; react thallium sulfide with dilute nitric acid to obtain thallium nitrate; or react thallium sulfide with dilute sulfuric acid to obtain thallium sulfate.

[0010] Step S4: The detoxified residue is mixed and ground with lepidolite and sodium sulfate and then roasted in a rotary kiln to obtain clinker. The clinker is then leached in water to obtain lithium-containing leachate.

[0011] Preferably, in step S1, the mass ratio of desulfurized gypsum to eluent is (2-10):1, and the eluent in step S1 is composed of a reducing agent and an alkali, with a mass ratio of reducing agent to alkali of (2-5):1; wherein the reducing agent includes, but is not limited to, one or more of sodium sulfite, sodium sulfide, sodium dithionite, and thiourea, and the alkali includes, but is not limited to, one or more of sodium hydroxide or potassium hydroxide, and the water washing treatment in step S2 is a three-stage countercurrent elution, with a liquid-to-solid ratio of (0.8-10):1; the water washing temperature is 60-80℃, and the water washing time is 0.5-2h.

[0012] Preferably, the amount of sulfide added in step S3 is 1.05-1.3 times the molar amount of thallium in the washing solution; the concentration of dilute nitric acid or dilute sulfuric acid in step S3 is 0.5mol / L-1mol / L; the mass ratio of lepidolite, calcium sulfate, and sodium sulfate in the detoxified residue in step S4, based on the mass of calcium sulfate, is 6:(1-3):(1-3); the calcination temperature is 800-1000℃, and the calcination time is 0.5-2h; the liquid-solid ratio of the clinker during water immersion in step S4 is (1-5):1; the water immersion temperature is 25-80℃, and the water immersion time is 0.5-2h.

[0013] A multi-stage washing and desiccation device includes: a primary washing tank, a secondary washing tank, and a tertiary washing tank placed on the ground;

[0014] A primary plate and frame filter press is used to perform solid-liquid separation by pressing and dewatering the mixture after primary washing;

[0015] A two-stage plate and frame filter press is used to perform solid-liquid separation by pressing and dewatering the primary filter cake after secondary water washing;

[0016] A three-stage plate and frame filter press is used to perform solid-liquid separation by dewatering after the secondary filter cake has undergone three-stage water washing;

[0017] The three discharge mechanisms are respectively used to discharge the solid filter cake and liquid clarified liquid separated by the first-stage plate and frame filter press, the second-stage plate and frame filter press, and the third-stage plate and frame filter press;

[0018] The feeding mechanism comprises three feeding mechanisms connected to the bottom of the primary washing tank, the secondary washing tank, and the tertiary washing tank, respectively. Each feeding mechanism includes a feeding pump and a feeding pipe. One end of each feeding pipe is connected to the bottom of the primary washing tank, the secondary washing tank, and the tertiary washing tank, respectively, and the other end of each feeding pipe is connected to the input end of the three feeding pumps. All three feeding pumps are located on the ground, and the output ends of each feeding pump are connected to a conveying pipe. One end of each conveying pipe is connected to the primary plate and frame filter press, the secondary plate and frame filter press, and the tertiary plate and frame filter press, respectively.

[0019] The six recycling tanks are located on the ground and are used to collect the clear liquid separated by the first-stage plate and frame filter press, the second-stage plate and frame filter press, and the third-stage plate and frame filter press, respectively.

[0020] The six recovery pipes are connected to the six recovery tanks and are respectively used to collect the clear liquid separated by the first-stage plate and frame filter press, the second-stage plate and frame filter press and the third-stage plate and frame filter press;

[0021] A filter cake box, which is set on the ground, is used to collect the three-stage filter cake.

[0022] Preferably, heating pipes are provided at the bottom of the inner walls of the primary washing tank, the secondary washing tank, and the tertiary washing tank, and two stirring mechanisms are provided at the bottom of the inner walls of the primary washing tank, the secondary washing tank, and the tertiary washing tank.

[0023] The stirring mechanism includes stirring shafts. Two stirring shafts are rotatably mounted on the bottom of the inner walls of the primary washing tank, the secondary washing tank, and the tertiary washing tank, respectively. A plurality of stirring blades are fixedly mounted on the surface of each of the six stirring shafts. The top ends of the six stirring shafts pass through the tops of the primary washing tank, the secondary washing tank, and the tertiary washing tank and extend to the outside. A stirring motor is fixedly connected to one end of each of the six stirring shafts located outside the primary washing tank, the secondary washing tank, and the tertiary washing tank. The six stirring motors are fixedly mounted on the tops of the primary washing tank, the secondary washing tank, and the tertiary washing tank through their housings.

[0024] Preferably, the primary plate and frame filter press includes a primary crossbeam, a primary fixing plate fixedly connected between two primary crossbeams, a primary hydraulic cylinder fixedly installed inside the primary fixing plate, a primary pressing plate slidably connected to the tops of the two primary crossbeams, one side of the primary pressing plate fixedly connected to the output end of the primary hydraulic cylinder, a primary thrust plate fixedly installed to the tops of the two primary crossbeams, and several primary filter plates slidably connected to the tops of the two primary crossbeams and between the primary pressing plate and the primary thrust plate, a primary feed main pipe connected to one side of the primary thrust plate, four primary compression pipes connected to one side of the primary thrust plate, and primary drain pipes connected to both sides of the several primary filter plates.

[0025] Preferably, the secondary plate and frame filter press is installed on the ground and located between the secondary washing tank and the tertiary washing tank. The secondary plate and frame filter press includes secondary crossbeams. Both secondary crossbeams are fixedly installed on the ground by fixed columns. A secondary fixing plate is fixedly connected between the two secondary crossbeams. A secondary hydraulic cylinder is fixedly installed inside the secondary fixing plate. A secondary pressing plate is slidably connected to the top of the two secondary crossbeams. One side of the secondary pressing plate is fixedly connected to the output end of the secondary hydraulic cylinder. A secondary thrust plate is fixedly installed to the top of the two secondary crossbeams. Several secondary filter plates are slidably connected to the top of the two secondary crossbeams and between the secondary pressing plate and the secondary thrust plate. A secondary feed main pipe is connected to one side of the secondary thrust plate. Four secondary compression pipes are connected to one side of the secondary thrust plate. Secondary drain pipes are connected to both sides of the several secondary filter plates.

[0026] Preferably, the three-stage plate and frame filter press is installed on the ground and located between the three-stage washing tank and the filter cake box. The three-stage plate and frame filter press includes three-stage crossbeams. Two of the three-stage crossbeams are fixedly installed on the ground by fixing columns. A three-stage fixing plate is fixedly connected between the two three-stage crossbeams. A three-stage hydraulic cylinder is fixedly installed inside the three-stage fixing plate. A three-stage pressing plate is slidably connected to the top of the two three-stage crossbeams. One side of the three-stage pressing plate is fixedly connected to the output end of the three-stage hydraulic cylinder. A three-stage thrust plate is fixedly installed on the top of the three-stage crossbeams. Several three-stage filter plates are slidably connected to the top of the two three-stage crossbeams and between the three-stage pressing plate and the three-stage thrust plate. A three-stage feed main pipe is connected to one side of the three-stage thrust plate. Four three-stage compression pipes are connected to one side of the three-stage thrust plate. Three-stage drain pipes are connected to both sides of the several three-stage filter plates. One end of the three conveying pipes is connected to one end of the first-stage feed main pipe, the second-stage feed main pipe and the third-stage feed main pipe, respectively.

[0027] Preferably, the discharge mechanism includes a discharge trough, which is fixedly installed on the ground by a support column. Two drainage trough shafts are rotatably installed on both sides of the discharge trough. The two drainage trough shafts pass through both sides of the discharge trough and extend into its interior. A lever is fixedly installed at the end of each drainage trough shaft inside the discharge trough, and a drainage trough is fixedly installed at the end of each drainage trough shaft outside the discharge trough. A stop post is fixedly installed on both sides of the discharge trough, and the stop post is adapted to the drainage trough. The six drainage troughs are adapted to several primary drainage pipes, several secondary drainage pipes, and several tertiary drainage pipes, respectively. The six drainage troughs are also adapted to six recovery pipes.

[0028] Preferably, a drive mechanism is rotatably mounted on one side of the inner wall of each of the three discharge troughs. The drive mechanism includes a screw, an auxiliary rod, and a water collection tank. One end of the screw is rotatably mounted on one side of the inner wall of the discharge trough, and the other end of the screw is rotatably mounted on one side of the inner wall of the discharge trough via a rotating frame. The screw penetrates the inner wall of the discharge trough and extends to the outside. A drive motor is fixedly connected to the end of the screw located outside the discharge trough. The drive motor is fixedly mounted on one side of the discharge trough via a housing. One end of the auxiliary rod is rotatably mounted on one side of the inner wall of the discharge trough, and the other end of the auxiliary rod is rotatably mounted on the inner wall of the discharge trough via a rotating frame. On one side, a drive plate is threadedly connected to the surface of the screw, and the interior of the drive plate is slidably connected to the surface of the auxiliary rod. Abutment grooves are fixedly installed on both sides of the discharge chute. The water collection tank is located on the ground, and a water collection trough is connected to the top of the water collection tank via a water pipe. Two abutment grooves are respectively fitted and installed to the two ends of the water collection trough. Two drainage troughs are respectively fitted and installed to the two abutment grooves. Connecting plates are fixedly installed on both sides of the drive plate. A rotating plate is rotatably installed at one end of each of the two connecting plates via a pin. The two rotating plates are fixedly connected to the two connecting plates by two springs. A lever plate is fitted and installed to the rotating plate.

[0029] Compared with related technologies, the resource recovery method for thallium in desulfurized gypsum provided by this invention has the following beneficial effects:

[0030] This invention provides a method for the resource-based recovery of thallium from desulfurized gypsum. By adding a reducing agent and employing a multi-stage elution process, trivalent thallium is converted into more mobile monovalent thallium, thereby achieving efficient and deep removal of thallium and transforming desulfurized gypsum into a non-toxic industrial raw material. Thallium in the washing solution is converted into thallium sulfide, which can be further processed into high-value-added products such as thallium nitrate / thallium sulfate, realizing the resource utilization of hazardous waste and creating economic benefits. Furthermore, the calcium and sulfur resources in desulfurized gypsum are synergistically utilized with lepidolite, and the CaSO4 component in the desulfurized gypsum is also utilized. It can perform dual functions: on the one hand, the SO2 gas phase component generated by its thermal decomposition can effectively promote the destruction of the lithium mica lattice; on the other hand, the calcium-based component can inhibit the dissolution of impurity elements. This characteristic makes it a substitute for the expensive potassium sulfate auxiliary material in the sulfate roasting process, realizing the high-value utilization of industrial solid waste; and it can construct a closed-loop technology system of "thallium removal-thallium recovery-gypsum utilization-lithium extraction", simultaneously solving three major industrial problems: heavy metal pollution control, solid waste resource utilization, and efficient lithium resource extraction, thus achieving a unity of environmental and economic benefits. Attached Figure Description

[0031] Figure 1 A process flow diagram of a method for the resource recovery of thallium from desulfurized gypsum;

[0032] Figure 2 A schematic diagram of a preferred embodiment of a multi-stage elution apparatus;

[0033] Figure 3 for Figure 1 The diagram shown is a structural schematic of the stirring mechanism.

[0034] Figure 4 for Figure 1 The diagram shown is a structural schematic of the feeding mechanism;

[0035] Figure 5 for Figure 1 The diagram shown is a structural schematic of a single-stage plate and frame filter press.

[0036] Figure 6 for Figure 1 The diagram shows the structure of a two-stage plate and frame filter press.

[0037] Figure 7 for Figure 1 The diagram shows the structure of a three-stage plate and frame filter press.

[0038] Figure 8 for Figure 1 The diagram shown is a structural schematic of the discharge mechanism;

[0039] Figure 9 This is a schematic diagram of a second embodiment of a multi-stage elution apparatus;

[0040] Figure 10Another structural schematic diagram of a second embodiment of a multi-stage elution apparatus;

[0041] Figure 11 for Figure 9 The diagram shows the structure of the drive mechanism.

[0042] Figure 12 for Figure 9 Another schematic diagram of the drive mechanism shown.

[0043] Numbered in the diagram: 1. Primary washing tank; 2. Secondary washing tank; 3. Tertiary washing tank; 4. Agitator; 401. Agitator motor; 402. Agitator shaft; 403. Agitator blades; 5. Primary plate and frame filter press; 501. Primary crossbeam; 502. Primary fixing plate; 503. Primary hydraulic cylinder; 504. Primary clamping plate; 505. Primary thrust plate; 506. Primary filter plate; 507. Primary feed manifold; 5 08. Primary compression pipe; 509. Primary drain pipe; 6. Secondary plate and frame filter press; 601. Secondary crossbeam; 602. Secondary fixing plate; 603. Secondary hydraulic cylinder; 604. Secondary clamping plate; 605. Secondary thrust plate; 606. Secondary filter plate; 607. Secondary feed main pipe; 608. Secondary compression pipe; 609. Secondary drain pipe; 7. Tertiary plate and frame filter press; 701. Tertiary crossbeam; 702. Tertiary... 703. Stage 3 fixed plate; 704. Stage 3 hydraulic cylinder; 705. Stage 3 clamping plate; 706. Stage 3 thrust plate; 707. Stage 3 filter plate; 708. Stage 3 feed manifold; 709. Stage 3 compression pipe; 800. Stage 3 drain pipe; 801. Discharge mechanism; 802. Discharge trough; 803. Drainage trough shaft; 804. Paddle plate; 805. Drainage trough; 901. Drive mechanism; 902. Screw; 903. Drive mechanism. Motor, 903, drive plate, 904, abutment trough, 905, water collection trough, 906, water collection tank, 907, connecting plate, 908, rotating plate, 909, spring, 910, auxiliary rod, 10, heating tube, 11, feeding mechanism, 1101, feeding pump, 1102, feeding pipe, 1103, conveying pipe, 12, recovery tank, 13, recovery pipe, 14, filter cake box, 15, clean water tank, 16, clean water pipe. Detailed Implementation

[0044] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0045] The desulfurized gypsum and lepidolite used in this invention are sourced from Yichun City, Jiangxi Province, and the thallium ion concentration is 0.59 mg / L.

[0046] This invention provides a method for the resource recovery of thallium from desulfurized gypsum;

[0047] First embodiment: Please refer to the following: Figure 1 It includes the following steps;

[0048] Step S1: Mix the desulfurized gypsum and eluent in a certain proportion to prepare a mixture;

[0049] Step S2: The mixture is washed with water, and solid-liquid separation is performed to obtain washing liquid and detoxified residue;

[0050] Step S3: Recycle the washing solution, add sulfide to the washing solution with a thallium concentration higher than 20 mg / L, filter to obtain thallium sulfide; react thallium sulfide with dilute nitric acid to obtain thallium nitrate; or react thallium sulfide with dilute sulfuric acid to obtain thallium sulfate.

[0051] Step S4: The detoxified residue is mixed and ground with lepidolite and sodium sulfate and then roasted in a rotary kiln to obtain clinker. The clinker is then leached in water to obtain lithium-containing leachate.

[0052] The mass ratio of desulfurized gypsum to eluent in step S1 is (2-10):1. The eluent in step S1 is composed of a reducing agent and an alkali, and the mass ratio of reducing agent to alkali is (2-5):1. The reducing agent includes, but is not limited to, one or more of sodium sulfite, sodium sulfide, sodium dithionite, and thiourea, and the alkali includes, but is not limited to, one or more of sodium hydroxide or potassium hydroxide.

[0053] The washing process in step S2 is a three-stage countercurrent elution, with a liquid-to-solid ratio of (0.8-10):1; a washing temperature of 60-80℃; and a washing time of 0.5-2 hours. Specifically, the three-stage countercurrent elution involves: first, the mixture undergoes a primary washing, using the same water as the secondary washing solution; after the primary washing, the mixture is dewatered using a primary plate and frame filter press for solid-liquid separation to obtain a primary clarified solution and a primary filter cake; the primary clarified solution is then processed in step S3; the primary filter cake undergoes a secondary washing... The secondary washing uses the same water as the tertiary washing solution. After the secondary washing, the filter cake is dehydrated and separated into a secondary clear liquid and a secondary filter cake by a secondary plate and frame filter press. The secondary clear liquid is discharged to the primary washing for recycling. The secondary filter cake is then subjected to a tertiary washing using industrial circulating water and evaporation condensate. After the tertiary washing, the filter cake is dehydrated and separated into a tertiary clear liquid and a tertiary filter cake by a tertiary plate and frame filter press. The tertiary clear liquid is discharged to the secondary washing for recycling, and the tertiary filter cake is processed in step S4.

[0054] The amount of sulfide added in step S3 is 1.05-1.3 times the molar amount of thallium in the washing solution. The concentration of dilute nitric acid or dilute sulfuric acid in step S3 is 0.5mol / L-1mol / L. The mass ratio of lepidolite, calcium sulfate, and sodium sulfate in the detoxified residue in step S4 is 6:(1-3):(1-3) based on the mass of calcium sulfate. The roasting temperature is 800-1000℃ and the roasting time is 0.5-2h. The liquid-solid ratio of the clinker during water immersion in step S4 is (1-5):1. The water immersion temperature is 25-80℃ and the water immersion time is 0.5-2h.

[0055] Table 1: Leaching toxicity data of different wash waters and final detoxification residues

[0056] sample Tl / ppm sample Tl / ppm Level 1 wash water 9.074 raw material 88.195 Secondary wash water 4.255 Detoxified residue 0.0026 Third-level washing 1.995 / /

[0057] Second embodiment: The method in this embodiment is the same as that in the first embodiment, except that the mass ratio of lepidolite: calcium sulfate: sodium sulfate is changed.

[0058] Table 2: Lithium solubility in clinker under different mass ratios of lepidolite:calcium sulfate:sodium sulfate

[0059] Experiment number Lithium mica percentage / % Calcium sulfate percentage Sodium sulfate percentage Lithium solubility / % 1 60 30 10 94.8 2 60 20 20 82.1 3 60 10 30 77.3

[0060] Third embodiment: The method in this embodiment is the same as that in the first embodiment, except that the leaching conditions of lepidolite clinker are changed.

[0061] Table 3: Lithium leaching rate under different lepidolite clinker leaching conditions

[0062] Experiment number Liquid-to-solid ratio Leaching temperature / °C Leaching time / h Lithium leaching rate / % 1 1：1 60 2 82.5 2 2：1 60 2 88.3 3 3：1 60 2 93.7 4 3：1 80 2 93.9 5 3：1 60 1 86.4

[0063] Compared with related technologies, the resource recovery method for thallium in desulfurized gypsum provided by this invention has the following beneficial effects:

[0064] This invention achieves efficient and deep removal of thallium by adding a reducing agent and using a multi-stage elution process to convert trivalent thallium into more mobile monovalent thallium, thus transforming desulfurized gypsum into a non-toxic industrial raw material. It also converts thallium in the washing solution into thallium sulfide, which can be further processed into high-value-added products such as thallium nitrate / thallium sulfate, realizing the resource utilization of hazardous waste and creating economic benefits. Furthermore, it synergistically utilizes the calcium and sulfur resources in desulfurized gypsum with lepidolite. The CaSO4 component in desulfurized gypsum can play a dual role: on the one hand, the SO2 gas phase component generated by its thermal decomposition can effectively promote the destruction of the lepidolite lattice; on the other hand, the calcium-based component can inhibit the dissolution of impurity elements. This characteristic allows it to replace the expensive potassium sulfate auxiliary material in the sulfate roasting process, achieving high-value utilization of industrial solid waste. Finally, it constructs a closed-loop technology system of "thallium removal - thallium recovery - gypsum utilization - lithium extraction," simultaneously solving three major industrial challenges: heavy metal pollution control, solid waste resource utilization, and efficient lithium extraction, achieving a balance between environmental and economic benefits.

[0065] This invention provides a multi-stage elution device;

[0066] First embodiment: Please refer to the following: Figures 2-7 It includes: a primary washing tank 1, a secondary washing tank 2, and a tertiary washing tank 3, all placed on the ground;

[0067] A primary plate and frame filter press 5 is used to perform solid-liquid separation by pressing and dewatering the mixture after primary washing.

[0068] A secondary plate and frame filter press 6 is used to perform solid-liquid separation by pressing and dewatering the primary filter cake after secondary water washing;

[0069] Three-stage plate and frame filter press 7, the three-stage plate and frame filter press 7 is used to perform solid-liquid separation by pressure filtration and dewatering after the secondary filter cake is washed three times with water;

[0070] The three discharge mechanisms 8 are respectively used to discharge the solid filter cake and liquid clarified liquid separated by the first-stage plate and frame filter press 5, the second-stage plate and frame filter press 6 and the third-stage plate and frame filter press 7;

[0071] Feeding mechanisms 11, three of which are respectively connected to the bottom of the primary washing tank 1, the secondary washing tank 2, and the tertiary washing tank 3. Each feeding mechanism 11 includes a feeding pump 1101 and a feeding pipe 1102. One end of each of the three feeding pipes 1102 is connected to the bottom of the primary washing tank 1, the secondary washing tank 2, and the tertiary washing tank 3, and the other end of each feeding pipe 1102 is connected to the input end of each of the three feeding pumps 1101. All three feeding pumps 1101 are located on the ground. The output end of each of the three feeding pumps 1101 is connected to a conveying pipe 1103. One end of each of the three conveying pipes 1103 is connected to the primary plate and frame filter press 5, the secondary plate and frame filter press 6, and the tertiary plate and frame filter press 7, respectively.

[0072] Recovery tank 12, six of the recovery tanks 12 are set on the ground and are used to recover the clear liquid separated by the first-stage plate and frame filter press 5, the second-stage plate and frame filter press 6 and the third-stage plate and frame filter press 7 respectively;

[0073] The six recovery pipes 13 are connected to the six recovery tanks 12 and are respectively used to collect the clear liquid separated by the first-stage plate and frame filter press 5, the second-stage plate and frame filter press 6 and the third-stage plate and frame filter press 7;

[0074] Cake box 14, which is set on the ground for recycling the three-stage filter cake.

[0075] Heating pipes 10 are installed at the bottom of the inner walls of the primary washing tank 1, the secondary washing tank 2, and the tertiary washing tank 3. Two stirring mechanisms 4 are installed at the bottom of the inner walls of each of the three tanks. Each stirring mechanism 4 includes a stirring shaft 402. The two stirring shafts 402 are rotatably mounted on the bottom of the inner walls of the primary washing tank 1, the secondary washing tank 2, and the tertiary washing tank 3, respectively. Several [unspecified items] are fixedly installed on the surfaces of the six stirring shafts 402. The top ends of the six stirring blades 403 and the six stirring shafts 402 respectively penetrate the top of the primary water washing tank 1, the secondary water washing tank 2 and the tertiary water washing tank 3 and extend to the outside. The six stirring shafts 402 are respectively fixedly connected to one end of the primary water washing tank 1, the secondary water washing tank 2 and the tertiary water washing tank 3. The six stirring motors 401 are respectively fixedly installed on the top of the primary water washing tank 1, the secondary water washing tank 2 and the tertiary water washing tank 3 through the outer shell.

[0076] The primary plate and frame filter press 5 is installed on the ground and located between the primary washing tank 1 and the secondary washing tank 2. The primary plate and frame filter press 5 includes two primary crossbeams 501, both of which are fixedly installed on the ground by fixed columns. A primary fixing plate 502 is fixedly connected between the two primary crossbeams 501. A primary hydraulic cylinder 503 is fixedly installed inside the primary fixing plate 502. A primary pressing plate 504 is slidably connected to the top of both primary crossbeams 501. One side of the primary pressing plate 504 is fixedly connected to the output end of the primary hydraulic cylinder 503. A primary thrust plate 505 is fixedly installed to the top of both primary crossbeams 501. A plurality of primary filter plates 506 are slidably connected to the top of the primary pressing plate 504 and the primary thrust plate 505. A primary feed main pipe 507 is connected to one side of the primary thrust plate 505, and four primary compression pipes 508 are connected to one side of the primary thrust plate 505. Primary drain pipes 509 are connected to both sides of the plurality of primary filter plates 506. The secondary plate and frame filter press 6 is installed on the ground between the secondary washing tank 2 and the tertiary washing tank 3. The secondary plate and frame filter press 6 includes secondary crossbeams 601. Both secondary crossbeams 601 are fixedly installed on the ground by fixing columns. A secondary fixing plate 602 is fixedly connected between the two secondary crossbeams 601. A secondary hydraulic cylinder 603 is fixedly installed inside the fixed plate 602. A secondary clamping plate 604 is slidably connected to the tops of the two secondary crossbeams 601. One side of the secondary clamping plate 604 is fixedly connected to the output end of the secondary hydraulic cylinder 603. A secondary thrust plate 605 is fixedly installed to the tops of the two secondary crossbeams 601. Several secondary filter plates 606 are slidably connected to the tops of the two secondary crossbeams 601 and between the secondary clamping plate 604 and the secondary thrust plate 605. A secondary feed manifold 607 is connected to one side of the secondary thrust plate 605, and four secondary compression pipes 608 are connected to the other side. Both sides of the several secondary filter plates 606 are... A secondary drain pipe 609 is connected to the tertiary plate and frame filter press 7, which is located on the ground between the tertiary washing tank 3 and the filter cake box 14. The tertiary plate and frame filter press 7 includes tertiary crossbeams 701, both of which are fixedly installed on the ground by fixed columns. A tertiary fixing plate 702 is fixedly connected between the two tertiary crossbeams 701. A tertiary hydraulic cylinder 703 is fixedly installed inside the tertiary fixing plate 702. A tertiary pressing plate 704 is slidably connected to the top of the two tertiary crossbeams 701. One side of the tertiary pressing plate 704 is fixedly connected to the output end of the tertiary hydraulic cylinder 703. A tertiary thrust plate 705 is fixedly installed to the top of the two tertiary crossbeams 701.Several tertiary filter plates 706 are slidably connected to the top of the two tertiary crossbeams 701 and between the tertiary clamping plate 704 and the tertiary thrust plate 705. A tertiary feed manifold 707 is connected to one side of the tertiary thrust plate 705, and four tertiary compression pipes 708 are connected to one side of the tertiary thrust plate 705. Tertiary drain pipes 709 are connected to both sides of the several tertiary filter plates 706. One end of each of the three conveying pipes 1103 is connected to one end of the primary feed manifold 507, the secondary feed manifold 607, and the tertiary feed manifold 707, respectively.

[0077] All three discharge mechanisms 8 are fixedly installed on the ground and located at the bottom of the primary plate and frame filter press 5, the secondary plate and frame filter press 6, and the tertiary plate and frame filter press 7, respectively. Each discharge mechanism 8 includes a discharge trough 801, which is fixedly installed on the ground by a support column. Drainage trough shafts 802 are rotatably installed on both sides of the discharge trough 801. Two of the drainage trough shafts 802 pass through one side of the discharge trough 801 and extend into it. The ends of the two drainage trough shafts 802 located inside the discharge trough 801 are fixedly installed... A deflector plate 803 is fixedly installed. Drainage channels 804 are fixedly installed at one end of the two drainage channel shafts 802 located outside the discharge channel 801. Abutment posts 805 are fixedly installed on both sides of the discharge channel 801. The abutment posts 805 are adapted to the drainage channels 804. The six drainage channels 804 are adapted to a plurality of primary drainage pipes 509, a plurality of secondary drainage pipes 609 and a plurality of tertiary drainage pipes 709 respectively. The six drainage channels 804 are adapted to a plurality of six recovery pipes 13 respectively.

[0078] In actual use, multiple sets of heating tubes 10 can be set; the primary water washing tank 1 is connected to the external mixing material supply channel; the tertiary water washing tank 3 is connected to the external industrial circulating water tank and evaporation condensate tank; the top of the secondary water washing tank 2 and the tertiary water washing tank 3 are provided with openings for the filter cake to enter.

[0079] The working principle of the multi-stage elution device provided by this invention is as follows:

[0080] First, the mixture is fed into the primary washing tank 1, and the stirring motor 401 is started. The primary washing water in the primary washing tank 1 is the secondary washing liquid. The rotation of the stirring motor 401 drives the stirring blades 403 to rotate via the stirring shaft 402, thus washing and mixing the mixture and the secondary washing liquid. After washing, the feed pump 1101 is started, and the mixture is drawn out through the feed pipe 1102 and fed into the primary feed manifold 507 through the feed pipe 1103. At this time, the primary hydraulic cylinder 503 is started, which pushes several primary filter plates 506 through the primary clamping plate 504. The several primary filter plates 506 are pressed against the primary thrust plate 505 to form a... The sealed filter chamber receives feed from the primary feed main pipe 507. Under the secondary pressure of compressed gas input through the primary compression pipe 508, the liquid in the washed mixture passes through the capillary pores in the primary filter plate 506 and is discharged as primary clear liquid through the primary drain pipe 509. The primary clear liquid is discharged from the primary drain trough 804 into the recovery tank 12 and then proceeds to step S3 for processing. The solids in the mixture form a primary filter cake in the filter chamber. The primary hydraulic cylinder 503 stops working. After the operator opens the primary filter plate 506, the primary filter cake falls into the discharge trough 801 below the primary filter plate 506 and is then placed into the secondary washing tank 2 by the operator.

[0081] Then, the primary filter cake undergoes a second water wash. The water used for the second water wash is the tertiary wash liquid. The stirring mechanism 4 and the secondary plate and frame filter press 6 in the secondary water wash tank 2 repeat the above process to obtain secondary clear liquid and secondary filter cake. The secondary clear liquid is discharged through the secondary drain pipe 609 into the corresponding drain tank 804 and then into the recovery tank 12. After recovery, it enters the interior of the primary water wash tank 1. After the operator opens the secondary filter plate 606, the secondary filter cake falls into the discharge chute 801 below the secondary filter plate 606, and the operator puts the secondary filter cake into the tertiary water wash tank 3.

[0082] Then, the secondary filter cake undergoes three water washes. The tertiary water wash uses industrial circulating water and evaporation condensate. The stirring mechanism 4 and the tertiary plate and frame filter press 7 in the tertiary water washing tank 3 repeat the above process to obtain tertiary clear liquid and tertiary filter cake. The tertiary clear liquid is discharged through the tertiary drain pipe 709 into the corresponding drain tank 804 and then into the recovery tank 12. After recovery, it enters the interior of the secondary water washing tank 2. After the staff opens the tertiary filter plate 706, the tertiary filter cake falls into the discharge trough 801 below the tertiary filter plate 706. The staff then puts the tertiary filter cake into the filter cake box 14 for step S4 processing.

[0083] Finally, the heating tube 10 is used to heat the liquid in the primary water washing tank 1, the secondary water washing tank 2 and the tertiary water washing tank 3 to adjust to the corresponding water washing temperature.

[0084] Compared with related technologies, the multi-stage elution device provided by the present invention has the following beneficial effects:

[0085] Solid-liquid separation is achieved by setting up a primary plate and frame filter press 5, a secondary plate and frame filter press 6, and a tertiary plate and frame filter press 7. The clear liquids from each stage are collected uniformly by the recovery tank 12. The separated liquids are gradually returned to achieve countercurrent reuse of the clear liquids to improve treatment efficiency and ensure that the thallium concentration is higher than 20 mg / L. The primary clear liquid then enters step S3 for treatment. The mixture undergoes three progressive water washings to gradually reduce the residual concentration and finally enters step S4 for treatment. By installing heating pipes 10 in the primary water washing tank 1, the secondary water washing tank 2, and the tertiary water washing tank 3, different water washing temperature requirements can be met.

[0086] Second embodiment: Please refer to the following: Figures 8-12 Based on the multi-stage elution apparatus provided in the first embodiment of this application, the second embodiment of this application proposes another multi-stage elution apparatus. 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.

[0087] Specifically, the difference in the multi-stage washing and desorption device provided in the second embodiment of this application is that three clean water pipes 16 are respectively connected to one side of the three feed pipes 1103, and three clean water tanks 15 are respectively connected to the end of the three clean water pipes 16. The three clean water tanks 15 are all set on the ground and are equipped with water pumps to supply water to the clean water pipes 16.

[0088] A drive mechanism 9 is rotatably mounted on one side of the inner wall of each of the three discharge troughs 801. The drive mechanism 9 includes a screw 901, an auxiliary rod 910, and a water collection tank 906. One end of the screw 901 is rotatably mounted on one side of the inner wall of the discharge trough 801, and the other end of the screw 901 is rotatably mounted on one side of the inner wall of the discharge trough 801 via a rotating frame. The screw 901 penetrates the inner wall of the discharge trough 801 and extends to the outside. A drive motor 902 is fixedly connected to the end of the screw 901 located outside the discharge trough 801. The drive motor 902 is fixedly mounted on one side of the discharge trough 801 through a housing. One end of the auxiliary rod 910 is rotatably mounted on one side of the inner wall of the discharge trough 801, and the other end of the auxiliary rod 910 is rotatably mounted on one side of the inner wall of the discharge trough 801 via a rotating frame. A drive plate 903 is threadedly connected to the surface of the screw 901. The interior of the drive plate 903 is slidably connected to the surface of the auxiliary rod 910. Abutment grooves 904 are fixedly installed on both sides of the discharge trough 801. The water collection tank 906 is located on the ground. The top of the water collection tank 906 is connected to a water collection trough 905 via a water pipe. The two abutment grooves 904 are respectively fitted and installed to the two ends of the water collection trough 905. The two drainage troughs 804 are respectively fitted and installed to the two abutment grooves 904. Connecting plates 907 are fixedly installed on both sides of the drive plate 903. A rotating plate 908 is rotatably installed at one end of each of the two connecting plates 907 via a pin. The two rotating plates 908 and the two connecting plates 907 are respectively fixedly connected by two springs 909. The lever plate 803 is fitted and installed to the rotating plate 908.

[0089] In actual use, the initial drainage end of the six drainage channels 804 is at the corresponding recycling tank 12.

[0090] The working principle of the multi-stage elution device provided in this embodiment is as follows:

[0091] When the filter cakes at each stage fall into the corresponding discharge trough 801, the corresponding drive mechanism 9 is activated. At this time, the drive motor 902 drives the screw 901 to rotate. The screw 901 is threadedly connected to the drive plate 903. The drive plate 903 pushes the filter cake to move. At this time, the clear liquid at each stage has been discharged. While the drive plate 903 is moving and pushing the filter cake, the rotating plate 908 contacts the deflector plate 803 and rotates clockwise. The spring 909 provides the support force. The deflector plate 803 drives the drainage trough 804 to rotate clockwise through the drainage trough shaft 802. After the drainage trough 804 contacts the abutment trough 904, the spring 909 is squeezed, and the rotating plate 908 rotates clockwise to disengage from the deflector plate 803. At this time, the center of gravity of the drainage trough 804 shifts to the abutment trough 904, and the water outlet changes to water outlet from the abutment trough 904. The drive plate 903 continues to move to complete the discharge of the filter cake.

[0092] After the outlet of the drain trough 804 is switched to the abutment trough 904, the corresponding clean water tank 15 is activated when the primary filter plate 506, secondary filter plate 606 and tertiary filter plate 706 need to be cleaned. The water pump in the clean water tank 15 supplies water to the clean water pipe 16. At this time, the feed pump 1101 does not work. Water is supplied from the feed pipe 1103 to the corresponding primary feed main pipe 507, secondary feed main pipe 607 and tertiary feed main pipe 707. The filter plates of each level are squeezed again, and the clean water flow washes the filter plates of each level. The cleaning liquid is then discharged from the corresponding primary drain pipe 509, secondary drain pipe 609 and tertiary drain pipe 709. The cleaning liquid flows from the drain trough 804 to the abutment trough 904 and into the water collection trough 905. The water collection trough 905 collects the liquid into the water collection tank 906. The cleaning liquid can be used for further purification.

[0093] After the above process is completed, the drive motor 902 reverses. At this time, the rotating plate 908 contacts the lever plate 803 again and drives it to rotate counterclockwise. When the drainage trough 804 contacts the abutment 805, the spring 909 stretches the rotating plate 908 to disengage from the lever plate 803. At this time, the drainage trough 804 is reset and ready for the next operation.

[0094] Compared with related technologies, the multi-stage elution device provided in this embodiment has the following beneficial effects:

[0095] After the filter cakes at each stage fall, the drive motor 902 is activated to move the drive plate 903, pushing out the filter cakes to complete the discharge. During the movement of the drive plate 903, the water outlet direction of the drainage trough 804 can be automatically switched. During the pushing process, the cleaning liquid is discharged from the abutment trough 904 and recycled to the water collection tank 906 for further purification, improving resource recovery efficiency. During the reset process, the system switches to normal operating state to discharge the clear liquid. The separate channels for collecting the clear liquid and discharging the cleaning liquid can avoid cross-contamination. The process is automatically switched without manual intervention. The spring 909 works with the abutment trough 904 and the abutment column 805 to ensure no displacement risk while the switching position is more accurate, ensuring that the water flows normally into the water collection tank 906 and the recovery tank 12. Cleaning the filter plates at each stage can maintain the efficiency of solid-liquid separation, improve purity, avoid residues affecting the separated clear liquid, extend the service life of the device, and prevent metal ion corrosion. The cleaned filter plates at each stage can avoid increasing the power consumption of the feed pump 1101.

[0096] 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 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. A multi-stage elution device for the resource recovery of thallium from desulfurized gypsum, characterized in that, include: Primary, secondary, and tertiary water washing tanks are placed on the ground. A primary plate and frame filter press is used to perform solid-liquid separation by pressing and dewatering the mixture after primary washing; A two-stage plate and frame filter press is used to perform solid-liquid separation by pressing and dewatering the primary filter cake after secondary water washing; A three-stage plate and frame filter press is used to perform solid-liquid separation by dewatering after the secondary filter cake has undergone three-stage water washing; The three discharge mechanisms are respectively used to discharge the solid filter cake and liquid clarified liquid separated by the first-stage plate and frame filter press, the second-stage plate and frame filter press, and the third-stage plate and frame filter press; The feeding mechanism comprises three feeding mechanisms connected to the bottom of the primary washing tank, the secondary washing tank, and the tertiary washing tank, respectively. Each feeding mechanism includes a feeding pump and a feeding pipe. One end of each feeding pipe is connected to the bottom of the primary washing tank, the secondary washing tank, and the tertiary washing tank, respectively, and the other end of each feeding pipe is connected to the input end of the three feeding pumps. All three feeding pumps are located on the ground, and the output ends of each feeding pump are connected to a conveying pipe. One end of each conveying pipe is connected to the primary plate and frame filter press, the secondary plate and frame filter press, and the tertiary plate and frame filter press, respectively. The six recycling tanks are located on the ground and are used to collect the clear liquid separated by the first-stage plate and frame filter press, the second-stage plate and frame filter press, and the third-stage plate and frame filter press, respectively. The six recovery pipes are connected to the six recovery tanks and are respectively used to collect the clear liquid separated by the first-stage plate and frame filter press, the second-stage plate and frame filter press, and the third-stage plate and frame filter press; A filter cake box, which is installed on the ground for recycling the three-stage filter cake; The primary plate and frame filter press is installed on the ground between the primary washing tank and the secondary washing tank. The primary plate and frame filter press includes two primary crossbeams, both fixed to the ground by fixed columns. A primary fixing plate is fixedly connected between the two primary crossbeams. A primary hydraulic cylinder is fixedly installed inside the primary fixing plate. A primary pressing plate is slidably connected to the tops of the two primary crossbeams. One side of the primary pressing plate is fixedly connected to the output end of the primary hydraulic cylinder. A primary thrust plate is fixedly installed to the tops of the two primary crossbeams. Several primary filter media are slidably connected to the tops of the two primary crossbeams, between the primary pressing plate and the primary thrust plate. The filter press consists of a primary plate and a secondary plate and frame filter press. One side of the primary thrust plate is connected to a primary feed main pipe, and one side of the primary thrust plate is connected to four primary compression pipes. Both sides of several primary filter plates are connected to primary drain pipes. The secondary plate and frame filter press is located on the ground between the secondary and tertiary washing tanks. The secondary plate and frame filter press includes secondary crossbeams. Two secondary crossbeams are fixedly installed on the ground via fixed columns. A secondary fixing plate is fixedly connected between the two secondary crossbeams. A secondary hydraulic cylinder is fixedly installed inside the secondary fixing plate. A secondary pressing plate is slidably connected to the top of both secondary crossbeams. One side of the secondary pressing plate is fixedly connected to the output end of the secondary hydraulic cylinder. A secondary thrust plate is fixedly installed on the top of the two secondary crossbeams. Several secondary filter plates are slidably connected to the top of the two secondary crossbeams and between the secondary pressure plate and the secondary thrust plate. A secondary feed main pipe is connected to one side of the secondary thrust plate, and four secondary compression pipes are connected to another side. Secondary drain pipes are connected to both sides of the several secondary filter plates. The tertiary plate and frame filter press is located on the ground between the tertiary washing tank and the filter cake box. The tertiary plate and frame filter press includes tertiary crossbeams. Both tertiary crossbeams are fixedly installed on the ground by fixed columns. A tertiary fixing plate is fixedly connected between the two tertiary crossbeams. The tertiary fixing plate is internally fixedly installed with… There is a three-stage hydraulic cylinder. The tops of the two three-stage crossbeams are slidably connected to a three-stage clamping plate. One side of the three-stage clamping plate is fixedly connected to the output end of the three-stage hydraulic cylinder. The tops of the two three-stage crossbeams are fixedly installed with a three-stage thrust plate. Several three-stage filter plates are slidably connected to the tops of the two three-stage crossbeams and between the three-stage clamping plate and the three-stage thrust plate. One side of the three-stage thrust plate is connected to a three-stage feed manifold. One side of the three-stage thrust plate is connected to four three-stage compression pipes. Both sides of the several three-stage filter plates are connected to three-stage drain pipes. One end of the three conveying pipes is connected to one end of the first-stage feed manifold, the second-stage feed manifold, and the third-stage feed manifold, respectively. All three discharge mechanisms are fixedly installed on the ground and located at the bottom of the first-stage plate and frame filter press, the second-stage plate and frame filter press, and the third-stage plate and frame filter press, respectively. Each discharge mechanism includes a discharge trough, which is fixedly installed on the ground by a support column. Drainage trough shafts are rotatably installed on both sides of the discharge trough. Two drainage trough shafts pass through both sides of the discharge trough and extend into it. A baffle plate is fixedly installed at one end of each drainage trough shaft inside the discharge trough, and a drainage trough is fixedly installed at one end of each drainage trough shaft outside the discharge trough. A stop post is fixedly installed on both sides of the discharge trough, and the stop post is adapted to the drainage trough. Six drainage troughs are adapted to several first-stage drainage pipes, several second-stage drainage pipes, and several third-stage drainage pipes, respectively. Six drainage troughs are adapted to six recovery pipes, respectively. A drive mechanism is rotatably mounted on one side of the inner wall of each of the three discharge troughs. Each drive mechanism includes a screw, an auxiliary rod, and a water collection tank. One end of the screw is rotatably mounted on one side of the inner wall of the discharge trough, and the other end is rotatably mounted on the same side via a rotating frame. The screw penetrates the inner wall of the discharge trough and extends to the outside. A drive motor is fixedly connected to the end of the screw located outside the discharge trough. The drive motor is fixedly mounted on one side of the discharge trough via a housing. One end of the auxiliary rod is rotatably mounted on one side of the inner wall of the discharge trough, and the other end is rotatably mounted on the same side via a rotating frame. The screw has a drive plate threadedly connected to its surface. The drive plate is slidably connected to the surface of the auxiliary rod. Abutment grooves are fixedly installed on both sides of the discharge chute. The water collection tank is located on the ground, and its top is connected to a water collection trough via a water pipe. Two abutment grooves are respectively fitted to the two ends of the water collection trough. Two drainage troughs are respectively fitted to the two abutment grooves. Connecting plates are fixedly installed on both sides of the drive plate. A rotating plate is rotatably installed on one end of each connecting plate via a pin. The two rotating plates are fixedly connected to the two connecting plates via two springs. The lever plate is fitted to the rotating plate.

2. The multi-stage elution apparatus according to claim 1, characterized in that, Heating pipes are installed at the bottom of the inner walls of the primary, secondary, and tertiary washing tanks. Two stirring mechanisms are installed at the bottom of the inner walls of the primary, secondary, and tertiary washing tanks. Each stirring mechanism includes a stirring shaft. The two stirring shafts are rotatably mounted on the bottom of the inner walls of the primary, secondary, and tertiary washing tanks, respectively. Several stirring blades are fixedly installed on the surface of each of the six stirring shafts. The top ends of the six stirring shafts pass through the tops of the primary, secondary, and tertiary washing tanks and extend to the outside. A stirring motor is fixedly connected to one end of each of the six stirring shafts located outside the primary, secondary, and tertiary washing tanks. The six stirring motors are fixedly mounted on the tops of the primary, secondary, and tertiary washing tanks through their housings.

3. The multi-stage elution apparatus according to claim 1, characterized in that, Each of the three conveying pipes is connected to one side of a clean water pipe, and each of the three clean water pipes is connected to one end of a clean water tank. The three clean water tanks are all located on the ground and are equipped with water pumps to supply water to the clean water pipes.

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