Eluting wastewater treatment equipment and arsenic-alkali residue resource recycling process

Abstract

The invention provides elution wastewater treatment equipment and an arsenic-alkali residue resource recycling process, and relates to the technical field of wastewater treatment, the elution wastewater treatment equipment comprises a base, a top pipe, a rotating cylinder and a flocculation mechanism; a mounting frame is fixedly arranged at the top of the base, a settling tank is mounted in the mounting frame, a discharge pump is mounted on the upper surface of the base and located below the settling tank, and a discharge pipe is hermetically mounted at the outlet end of the discharge pump; the top end of the top pipe is rotationally connected with a rotating cylinder, the flocculation mechanism comprises a side plate fixedly arranged on the side wall of the top pipe, and a mounting plate is mounted on the outer wall of the side plate. According to the scheme, the flocculation plates are overturned and mixed from the middle of the rotating cylinder to the outer side in a reciprocating manner, so that a mixed flow field is attached to the radial space distribution characteristic of the rotating cylinder, the problem that a conventional stirring center is strong and the edge is weak is solved, and meanwhile, the requirements of chemical diffusion, floc growth and scale and deposition prevention of arsenic-alkali residue elution wastewater combined with calcium hydroxide flocculation are met; and calcium hydroxide is fully and uniformly diffused to the cylinder wall from the feeding core area along the radial direction at a constant speed.

Description

A washing wastewater treatment device and a process for the resource recovery of arsenic-alkali residue. Technical Field

[0001] This invention relates to the field of wastewater treatment, and more particularly to a washing wastewater treatment device and a process for the resource recovery of arsenic-alkali residue. Background Technology

[0002] Arsenic alkali slag is a typical high-risk waste generated in the non-ferrous metal smelting industry. It mainly comes from the wet arsenic removal section of flue gas in the smelting process of antimony, lead, tin and other metals. It is an alkaline waste residue formed after pressure filtration, and its composition is complex and extremely toxic.

[0003] Arsenic-alkali residue contains valuable substances, so developing a low-temperature, high-efficiency, highly selective, and near-zero-emission graded recovery technology for arsenic and antimony has become an urgent need in the industry. However, the direct discharge of leaching wastewater generated during the leaching process of arsenic-alkali residue will pollute the environment. This type of wastewater is classified as arsenic-containing hazardous wastewater and is also characterized by high alkalinity, high oxalic acid, and high salinity. Direct discharge will exceed the environmental carrying capacity of water bodies and soil, causing a series of environmental problems such as the death of aquatic organisms, permanent soil pollution, groundwater exceeding standards, and bioaccumulation in the food chain. Therefore, the leaching wastewater needs to be treated before it can be discharged or recycled.

[0004] In existing technologies, during the flocculation treatment of elution wastewater, conventional stirring can easily result in a radial gradient where the reagent concentration is high in the center of the drum and low at the edge. Excessive calcium hydroxide in the center can easily generate fine calcium oxalate that is difficult to aggregate into flocs, while insufficient calcium hydroxide at the edge can lead to incomplete reaction of oxalic acid and arsenic, resulting in a low removal rate.

[0005] Therefore, it is necessary to provide a washing wastewater treatment device and an arsenic-alkali residue resource recovery process to solve the above-mentioned technical problems. Summary of the Invention

[0006] This invention provides a washing wastewater treatment device and a process for the resource recovery of arsenic-alkali residue, which solves the problem in related technologies where conventional stirring easily results in a radial gradient with high reagent concentration in the center of the cylinder and low concentration on the edge wall, which can easily affect the flocculation effect.

[0007] To solve the above-mentioned technical problems, the present invention provides a washing wastewater treatment device, including a base, a top pipe, a rotating cylinder and a flocculation mechanism;

[0008] A mounting frame is fixed on the top of the base, a sedimentation tank is installed inside the mounting frame, a discharge pump is installed on the upper surface of the base and below the sedimentation tank, and a discharge pipe is sealed at the outlet end of the discharge pump.

[0009] A rotating cylinder is rotatably connected to the top of the jacking pipe. The flocculation mechanism includes a side plate fixed to the side wall of the jacking pipe. An installation plate is installed on the outer wall of the side plate. A motor is installed on the top of the installation plate. A drive pulley is connected to the output shaft of the motor via a keyway. A positioning plate is fixed to the side wall of the side plate. A driven pulley is rotatably connected inside the positioning plate. A belt is sleeved on the outer wall of the drive pulley and the driven pulley. A drive plate is connected to the shaft center of the driven pulley via a keyway. A moving plate is rotatably connected to the outer wall of the side plate and below the positioning plate. A first connecting plate and a second connecting plate are rotatably connected to the outer wall of the moving plate. A flocculation plate is rotatably connected to the top of the first connecting plate and the second connecting plate.

[0010] Preferably, the drive plate and the positioning plate are rotatably connected, and the top of the drive plate is rotatably connected to the outer wall of the flocculation plate.

[0011] Preferably, the cross-section of the flocculation plate is arc-shaped, and one end of the flocculation plate extends into the interior of the rotating cylinder.

[0012] Preferably, the inlet end of the discharge pump and the outlet end of the sedimentation tank are sealed together, and the rotating cylinder, the top pipe and the sedimentation tank are interconnected.

[0013] Preferably, it also includes an adjustment mechanism;

[0014] The adjustment mechanism includes a positioning frame fixed to the upper surface of the sedimentation tank, an extrusion cylinder installed inside the positioning frame, an elastic piston installed inside the extrusion cylinder, a guide wheel installed on the top of the elastic piston, and a discharge pipe and a feed pipe installed at the bottom of the extrusion cylinder respectively.

[0015] A rotating rod is fixed at the rotatable connection between the moving plate and the side plate. A limiting plate is installed on the outer wall of the side plate and on one side of the rotating rod. A positioning sleeve is rotatably connected inside the limiting plate. A cam is fixed on the outer wall of the positioning sleeve. A positioning bolt is threaded inside the positioning sleeve.

[0016] Preferably, the inlet end of the feed pipe extends through the interior of the sedimentation tank, and the guide wheel and the cam are in contact with each other.

[0017] Preferably, the rotating rod passes through the inside of the cam and the positioning sleeve and does not contact the cam and the positioning sleeve, and the positioning bolt extends to the surface of the rotating rod.

[0018] Preferably, a positioning seat is fixed on the upper surface of the top pipe and located on one side of the rotating cylinder, a worm gear is connected to the keyway at the center of the drive pulley shaft, and a worm wheel is fixed on the outer wall of the rotating cylinder;

[0019] The worm is rotatably connected to the positioning seat, and the worm and the worm wheel mesh with each other.

[0020] The arsenic-alkali residue resource recovery process includes the following steps:

[0021] S1: Selective oxidative elution of arsenic;

[0022] Arsenic-alkali residue is mixed with an acidic solution containing a composite oxidant in a certain proportion and an oxidation reaction is carried out under low temperature conditions. The composite oxidant is composed of persulfate and organic acid. Persulfate acts as a strong oxidant and efficiently oxidizes the more toxic trivalent arsenic to pentavalent arsenic under acidic conditions, generating arsenic acid that is easily soluble in water.

[0023] Meanwhile, organic acids form stable complexes with arsenic acid through their carboxyl groups, further enhancing the solubility of arsenic and selectively inhibiting the dissolution of antimony, thus avoiding co-dissolution of arsenic and antimony. After the reaction is completed, solid-liquid separation is carried out by centrifugation or pressure filtration to obtain a high-arsenic-concentration eluent and a solid residue with low arsenic residue.

[0024] S2: Antimony targeted chelation elution;

[0025] The solid residue after S1 separation is mixed with an acidic solution containing iron salt and chelating agent, and the reaction is carried out under ultrasonic assistance. The iron salt is hydrolyzed to generate ferric hydroxide colloid, which effectively adsorbs the silicate components in the residue, inhibits the formation of silica gel, and prevents it from encapsulating antimony.

[0026] Chelating agents form stable water-soluble complexes with pentavalent antimony through coordination of hydroxyl and carboxyl groups, achieving efficient antimony dissolution.

[0027] After the reaction is complete, the antimony-rich eluent and the final harmless residue are obtained by filtration or sedimentation separation;

[0028] S3: Arsenic recovery;

[0029] A sulfiding agent is introduced into the arsenic-rich eluent, and a high-purity arsenic sulfide solid is generated through a sulfidation precipitation reaction. After washing and drying, it can be directly recovered as an arsenic product.

[0030] Antimony recovery;

[0031] Antimony can be recovered from antimony-rich eluents using either electrodeposition or chemical precipitation. Electrodeposition involves adjusting the current density and electrolyte pH to directly deposit metallic antimony on the cathode surface, while chemical precipitation involves adding an alkaline precipitant to generate sodium pyroantimonate or antimony oxide products.

[0032] S4: The eluted wastewater is neutralized, filtered, and adsorbed by activated carbon to remove residual acid, heavy metal ions, and organic matter. It is then reused in the arsenic elution section of S1 to form a closed-loop system, achieving near-zero wastewater discharge. The elution wastewater needs to be neutralized and flocculated in a rotary drum and finally settled in a sedimentation tank. The discharge pump discharges the solid flocculent solids. The treated wastewater in the sedimentation tank can be recycled or discharged.

[0033] Compared with related technologies, the elution wastewater treatment equipment and arsenic-alkali residue resource recovery process provided by the present invention have the following beneficial effects:

[0034] The flocculant plate rotates and mixes from the center of the rotating cylinder to the outside, making the mixing flow field conform to the radial spatial distribution characteristics of the rotating cylinder, avoiding the problem of strong center and weak edge of conventional stirring. At the same time, it is suitable for the needs of reagent diffusion, floc growth, scale prevention and deposition prevention in the washing wastewater of arsenic alkali residue combined with calcium hydroxide flocculant.

[0035] This ensures that calcium hydroxide diffuses uniformly and radially from the core addition area to the cylinder wall, guaranteeing a consistent calcium hydroxide concentration at any radial position within the rotating cylinder. The reactions of oxalate and arsenate with calcium hydroxide occur synchronously throughout the entire area. Attached Figure Description

[0036] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0037] Figure 1 is a schematic diagram of the optimal structure provided by the present invention;

[0038] Figure 2 is a schematic diagram of the back structure shown in Figure 1;

[0039] Figure 3 is a magnified structural diagram of point A shown in Figure 1;

[0040] Figure 4 is a schematic diagram of the enlarged structure at point B shown in Figure 2;

[0041] Figure 5 is a detailed connection diagram of the cam and the limiting plate shown in Figure 4;

[0042] Figure 6 is a schematic diagram of the initial working state of the flocculation mechanism provided by the present invention;

[0043] Figure 7 is a schematic diagram of the working state of controlling the movement of the flocculation plate when the drive plate rotates clockwise as shown in Figure 6.

[0044] Figure 8 is a schematic diagram of the working state of the flocculation plate controlled by the continuous rotation of the drive plate shown in Figure 7.

[0045] Figure 9 is a schematic diagram of the working state of the flocculation plate controlled by the continuous rotation of the drive plate in Figure 8, which controls the mixing and flocculation motion inside the rotating cylinder.

[0046] Figure 10 is a schematic diagram of the detailed connection structure of the worm and worm wheel provided by the present invention.

[0047] Explanation of icon numbers:

[0048] 1. Base; 2. Mounting bracket; 3. Sedimentation tank;

[0049] 4. Pipe jacking; 5. Rotating drum;

[0050] 6. Flocculation mechanism; 61. Side plate; 62. Mounting plate; 63. Motor; 64. Drive pulley; 65. Positioning plate; 66. Driven pulley; 67. Belt; 68. Drive plate; 69. Motion plate; 610. First connecting plate; 611. Second connecting plate; 612. Flocculation plate.

[0051] 7. Adjustment mechanism; 71. Positioning frame; 72. Extrusion cylinder; 73. Elastic piston; 74. Guide wheel; 75. Feed tube; 76. Feed pipe; 77. Limiting plate; 78. Cam; 79. Rotating rod; 710. Positioning sleeve; 711. Positioning bolt.

[0052] 8. Discharge pump; 9. Discharge pipe;

[0053] 10. Worm gear, 11. Positioning seat, 12. Worm wheel. Detailed Implementation

[0054] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0055] This invention provides a washing wastewater treatment device and a process for the resource recovery of arsenic-alkali residue.

[0056] First embodiment:

[0057] Please refer to Figures 1, 3, 6 to 10. A washing wastewater treatment device includes a base 1, a top pipe 4, a rotating cylinder 5, and a flocculation mechanism 6.

[0058] The base 1 is fixedly provided with a mounting frame 2, and a sedimentation tank 3 is installed inside the mounting frame 2. A discharge pump 8 is installed on the upper surface of the base 1 and below the sedimentation tank 3. A discharge pipe 9 is sealed at the outlet end of the discharge pump 8.

[0059] The top of the jacking pipe 4 is rotatably connected to a rotating cylinder 5. The flocculation mechanism 6 includes a side plate 61 fixed to the side wall of the jacking pipe 4. An installation plate 62 is installed on the outer wall of the side plate 61. A motor 63 is installed on the top of the installation plate 62. A drive pulley 64 is connected to the output shaft of the motor 63 via a keyway. A positioning plate 65 is fixed to the side wall of the side plate 61. A driven pulley 66 is rotatably connected inside the positioning plate 65. A belt 67 is sleeved on the outer wall of the drive pulley 64 and the driven pulley 66. A drive plate 68 is connected to the shaft of the driven pulley 66 via a keyway. A moving plate 69 is rotatably connected to the outer wall of the side plate 61 and below the positioning plate 65. A first connecting plate 610 and a second connecting plate 611 are rotatably connected to the outer wall of the moving plate 69. A flocculation plate 612 is rotatably connected to the top of the first connecting plate 610 and the second connecting plate 611.

[0060] The drive plate 68 and the positioning plate 65 are rotatably connected, and the top of the drive plate 68 is rotatably connected to the outer wall of the flocculation plate 612.

[0061] The flocculation plate 612 has an arc-shaped cross-section, and one end of the flocculation plate 612 extends into the interior of the rotating cylinder 5.

[0062] The inlet end of the discharge pump 8 and the outlet end of the sedimentation tank 3 are sealed together, and the rotating cylinder 5, the jacking pipe 4 and the sedimentation tank 3 are interconnected.

[0063] Please refer to Figures 3 and 6: The elution wastewater needs to be injected into the rotating drum 5, and then the oxalic acid flocculation of the elution wastewater is removed by injecting calcium hydroxide into the center end of the rotating drum 5;

[0064] The user starts the motor 63 to control the drive pulley 64 to rotate clockwise. During the clockwise rotation of the drive pulley 64, the transmission belt 67 controls the drive plate 68 to rotate continuously clockwise.

[0065] Please refer to Figures 3 and 7: During the clockwise rotation of the drive plate 68, the flocculation plate 612 is pulled from the center of the rotating cylinder 5 to the outer edge. At the same time, the flocculation plate 612 pulls the first connecting plate 610 and the second connecting plate 611 to control the motion plate 69 to rotate upward adaptively.

[0066] Please refer to Figure 8: As the drive plate 68 continues to rotate clockwise, the drive plate 68 pulls the flocculation plate 612 from the outer edge of the right side of the rotating cylinder 5 to the outer edge of the left side. At this time, the flocculation plate 612 controls the first connecting plate 610 and the second connecting plate 611 to be subjected to downward force on the moving plate 69. At this time, the moving plate 69 rotates counterclockwise about the hinge of the side plate 61.

[0067] Please refer to Figure 9: As the drive plate 68 continues to rotate and quickly returns to its initial state, the flocculation plate 612, the first connecting plate 610, the second connecting plate 611, and the moving plate 69 also move and return to their initial state. Therefore, by continuously rotating the drive plate 68, the flocculation plate 612 can be controlled to reciprocate and flip inside the rotating cylinder 5 to mix and flocculate the washing wastewater and calcium hydroxide inside the rotating cylinder 5.

[0068] This embodiment:

[0069] The flocculant plate 612 rotates and mixes from the middle of the rotating cylinder 5 outwards, so that the mixing flow field conforms to the radial spatial distribution characteristics of the rotating cylinder 5, avoiding the problem of strong center and weak edge of conventional stirring. At the same time, it is suitable for the needs of reagent diffusion, floc growth, scale prevention and deposition prevention in the washing wastewater of arsenic alkali residue combined with calcium hydroxide flocculant.

[0070] This ensures that calcium hydroxide diffuses radially from the core addition area to the cylinder wall at a uniform speed, guaranteeing that the calcium hydroxide concentration is consistent at any radial position within the rotating cylinder 5, and that the reactions of oxalate, arsenate, and calcium hydroxide occur synchronously throughout the entire area.

[0071] The wastewater from arsenic-alkali residue washing is treated and then recycled, achieving standard discharge through a dual treatment method. This approach addresses the characteristics of wastewater derived from hazardous wastes like arsenic-alkali residue, protecting the ecological environment from multiple dimensions, including water ecology protection, soil and groundwater control, and solid waste reduction. It also solves the environmental pollution risk of heavy metal pollutants from direct discharge of wastewater.

[0072] Second embodiment:

[0073] Please refer to Figures 2, 4 and 5, which also include the adjustment mechanism 7;

[0074] The adjustment mechanism 7 includes a positioning frame 71 fixed to the upper surface of the sedimentation tank 3. An extrusion cylinder 72 is installed inside the positioning frame 71. An elastic piston 73 is installed inside the extrusion cylinder 72. A guide wheel 74 is installed on the top of the elastic piston 73. A feed pipe 75 and a feed pipe 76 are respectively installed at the bottom of the extrusion cylinder 72.

[0075] A rotating rod 79 is fixed at the rotatable connection between the moving plate 69 and the side plate 61. A limiting plate 77 is installed on the outer wall of the side plate 61 and on one side of the rotating rod 79. A positioning sleeve 710 is rotatably connected inside the limiting plate 77. A cam 78 is fixed on the outer wall of the positioning sleeve 710. A positioning bolt 711 is threaded inside the positioning sleeve 710.

[0076] The inlet end of the feed pipe 75 extends through the interior of the sedimentation tank 3, and the guide wheel 74 and the cam 78 are in contact with each other.

[0077] The rotating rod 79 passes through the interior of the cam 78 and the positioning sleeve 710 and does not contact the cam 78 and the positioning sleeve 710. The positioning bolt 711 extends to the surface of the rotating rod 79.

[0078] Please refer to Figure 5: As can be seen from the working state of the first embodiment, the motion plate 69 is affected by the rotation of the drive plate 68 and performs a reciprocating rotational motion. Therefore, the motion plate 69 can drive the rotating rod 79 to reciprocate within the positioning sleeve 710 and the cam 78. The wastewater in the rotating cylinder 5 will enter the sedimentation tank 3 through the top pipe 4 for sedimentation. Therefore, during the sedimentation process, the user can rotate the positioning bolt 711 and the force-bearing rotating rod 79 according to the actual situation. When the rotating rod 79 rotates, it can simultaneously drive the positioning sleeve 710 and the cam 78 to reciprocate and flip on the limiting plate 77.

[0079] Please refer to Figures 2 and 4: When the long end of the cam 78 rotates to the position of the guide wheel 74, it can be subjected to downward force to control the guide wheel 74 to control the elastic piston 73 to compress in the extrusion cylinder 72, and squeeze the lime slurry in the extrusion cylinder 72 into the sedimentation tank 3 through the feed pipe 75 for pH adjustment.

[0080] Understandably, users can install a lime slurry storage device outside the feed pipe 76 to ensure that lime slurry can be continuously supplied to the sedimentation tank 3. Secondly, a one-way valve can be set to ensure that the feed pipe 76 passes through the extrusion cylinder 72 in one direction, and a one-way valve can also be set on the discharge pipe 75 to ensure that the extrusion cylinder 72 passes through the sedimentation tank 3 in one direction.

[0081] During the operation of the first embodiment, when the motion plate 69 returns to the initial state, the user can loosen the positioning bolt 711, and the cam 78 returns to the initial state.

[0082] This embodiment:

[0083] In the sedimentation stage of arsenic alkali residue washing wastewater, lime milk is added in a quantitative manner to adjust the pH. Combined with the core characteristics of this wastewater, which contains arsenic, oxalic acid, is high in salt, and is prone to calcium salt precipitation, precise pH control can be achieved. The precipitation of calcium oxalate and calcium arsenic salt in arsenic alkali residue washing wastewater has strict pH range requirements. The quantitative addition of lime milk can achieve precise and stable pH control and avoid precipitation failure due to pH fluctuations.

[0084] The quantitative addition of lime slurry can stably control the pH of the sedimentation tank at 8.0~9.5, allowing for full reaction and formation of calcium oxalate precipitate. The quantitative addition of lime slurry can precisely connect the pH to 8.5~10.0, which highly overlaps with the pH range of calcium oxalate precipitation, enabling oxalic acid and arsenic to precipitate simultaneously in the same pH range without the need for staged pH adjustment, greatly simplifying the process steps and improving processing efficiency.

[0085] Third embodiment:

[0086] Please refer to Figures 1, 3 and 10. The rotating rod 79 passes through the interior of the cam 78 and the positioning sleeve 710 and does not contact the cam 78 and the positioning sleeve 710. The positioning bolt 711 extends to the surface of the rotating rod 79.

[0087] A positioning seat 11 is fixed on the upper surface of the top pipe 4 and on one side of the rotating cylinder 5. A worm gear 10 is connected to the shaft of the drive pulley 64 via a keyway. A worm wheel 12 is fixed on the outer wall of the rotating cylinder 5.

[0088] The worm 10 is rotatably connected to the positioning seat 11, and the worm 10 and the worm wheel 12 mesh with each other.

[0089] Please refer to Figures 1 and 3: During the operation of the first embodiment, the drive pulley 64 rotates and can drive the worm gear 10 to rotate within the positioning seat 11. During the rotation of the worm gear 10, it can mesh with the drive worm wheel 12 to drive the rotating cylinder 5 to rotate on the top pipe 4, thereby realizing that the washing wastewater and calcium hydroxide in the rotating cylinder 5 rotate synchronously during the tumbling flocculation process.

[0090] This embodiment:

[0091] When the rotating drum 5 rotates automatically, the wastewater and calcium hydroxide reagent inside the drum will form a radial circulation from the center of the drum to the wall of the drum under the action of centrifugal force, realizing forced mixing without dead corners in the whole volume. For arsenic alkali residue washing wastewater, it can make the calcium hydroxide reagent quickly and evenly diffuse into the whole drum, avoiding the problem of too much reagent in the center of the rotating drum 5 and insufficient reaction at the edge.

[0092] Secondly, the continuous swirling flow causes the micro-flocs to undergo orderly collision and aggregation within the cylinder, rather than random collisions within a fixed cylinder. This ultimately forms large flocs with uniform particle size, high density, and good settling properties, laying a core foundation for subsequent solid-liquid separation.

[0093] The arsenic-alkali residue resource recovery process includes the following steps:

[0094] S1: Selective oxidative elution of arsenic;

[0095] Arsenic-alkali residue is mixed with an acidic solution containing a composite oxidant in a certain proportion and an oxidation reaction is carried out under low temperature conditions. The composite oxidant is composed of persulfate and organic acid. Persulfate acts as a strong oxidant and efficiently oxidizes the more toxic trivalent arsenic to pentavalent arsenic under acidic conditions, generating arsenic acid that is easily soluble in water.

[0096] Meanwhile, organic acids form stable complexes with arsenic acid through their carboxyl groups, further enhancing the solubility of arsenic and selectively inhibiting the dissolution of antimony, thus avoiding co-dissolution of arsenic and antimony. After the reaction is completed, solid-liquid separation is carried out by centrifugation or pressure filtration to obtain a high-arsenic-concentration eluent and a solid residue with low arsenic residue.

[0097] S2: Antimony targeted chelation elution;

[0098] The solid residue after S1 separation is mixed with an acidic solution containing iron salt and chelating agent, and the reaction is carried out under ultrasonic assistance. The iron salt is hydrolyzed to generate ferric hydroxide colloid, which effectively adsorbs the silicate components in the residue, inhibits the formation of silica gel, and prevents it from encapsulating antimony.

[0099] Chelating agents form stable water-soluble complexes with pentavalent antimony through coordination of hydroxyl and carboxyl groups, achieving efficient antimony dissolution.

[0100] After the reaction is complete, the antimony-rich eluent and the final harmless residue are obtained by filtration or sedimentation separation;

[0101] S3: Arsenic recovery;

[0102] A sulfiding agent is introduced into the arsenic-rich eluent, and a high-purity arsenic sulfide solid is generated through a sulfidation precipitation reaction. After washing and drying, it can be directly recovered as an arsenic product.

[0103] Antimony recovery;

[0104] Antimony can be recovered from antimony-rich eluents using either electrodeposition or chemical precipitation. Electrodeposition involves adjusting the current density and electrolyte pH to directly deposit metallic antimony on the cathode surface, while chemical precipitation involves adding an alkaline precipitant to generate sodium pyroantimonate or antimony oxide products.

[0105] S4: The eluted wastewater is neutralized, filtered, and adsorbed by activated carbon to remove residual acid, heavy metal ions, and organic matter. It is then reused in the arsenic elution section of S1 to form a closed-loop system, achieving near-zero wastewater discharge. The elution wastewater needs to be neutralized and flocculated in the rotary drum 5, and finally settled in the sedimentation tank 3. The discharge pump 8 discharges the solid flocculent solids. The treated wastewater in the sedimentation tank 3 can be recycled or discharged.

[0106] This process addresses the common shortcomings of traditional technologies by innovatively coupling oxidation regulation, complexation enhancement, and anti-interference separation mechanisms to overcome the technical bottlenecks of efficient arsenic and antimony separation and simultaneous resource recovery. It provides the industry with a green and low-carbon hazardous waste treatment solution, achieving highly selective separation and resource recovery of arsenic and antimony, significantly reducing waste liquid discharge, and solving the core defects of traditional processes such as high energy consumption, low separation efficiency, and high risk of secondary pollution.

[0107] Please refer again to Figures 1 to 10. The working principle of the elution wastewater treatment equipment and arsenic-alkali residue resource recovery process provided by the present invention is as follows:

[0108] Step S1: The elution wastewater needs to be injected into the rotating drum 5. Then, calcium hydroxide is injected into the center of the rotating drum 5 to remove oxalic acid and flocculate the elution wastewater. During neutralization and flocculation, the user starts the motor 63 to control the drive pulley 64 to rotate clockwise. During the clockwise rotation of the drive pulley 64, the transmission belt 67 controls the drive plate 68 to rotate continuously clockwise. During the clockwise rotation of the drive plate 68, the flocculant plate 612 is pulled from the center of the rotating drum 5 to the outer edge. At the same time, the flocculant plate 612 pulls the first connecting plate 610 and the second connecting plate 611 to control the moving plate 69 to rotate upward adaptively. Therefore, by continuously rotating the drive plate 68, the flocculant plate 612 can be controlled to flip back and forth in the rotating drum 5 to mix and flocculate the elution wastewater and calcium hydroxide in the rotating drum 5.

[0109] Step S2: The wastewater in the rotating cylinder 5 will enter the sedimentation tank 3 through the top pipe 4 for sedimentation. Therefore, during the sedimentation process, the user can rotate the positioning bolt 711 and the force-bearing rotating rod 79 according to the actual situation. When the rotating rod 79 rotates, it can simultaneously drive the positioning sleeve 710 and the cam 78 to reciprocate on the limit plate 77. When the long end of the cam 78 rotates to the guide wheel 74, it can be forced downward to control the guide wheel 74 to control the elastic piston 73 to compress in the extrusion cylinder 72, and squeeze the lime milk in the extrusion cylinder 72 into the sedimentation tank 3 through the feed pipe 75 for pH adjustment.

[0110] The above description is only a preferred embodiment of the present invention and does not limit the patent scope of the present invention. All equivalent structural transformations made under the concept of the present invention using the contents of the present invention specification and drawings, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present invention.

Claims

1. A wastewater treatment device for elution, characterized in that, The system includes a base, a top pipe, a rotating cylinder, and a flocculation mechanism. A mounting frame is fixed to the top of the base, and a sedimentation tank is installed inside the mounting frame. A discharge pump is installed on the upper surface of the base below the sedimentation tank, and a discharge pipe is sealed at the outlet end of the discharge pump. The rotating cylinder is rotatably connected to the top of the top pipe. The flocculation mechanism includes a side plate fixed to the side wall of the top pipe. An mounting plate is installed on the outer wall of the side plate, and a motor is installed on the top of the mounting plate. A drive pulley is connected to the output shaft of the motor via a keyway. A positioning plate is fixed to the side wall of the side plate, and a driven pulley is rotatably connected inside the positioning plate. A belt is fitted onto the outer walls of the drive pulley and the driven pulley. A drive plate is connected via a keyway at the shaft center of the driven pulley. A moving plate is rotatably connected to the outer wall of the side plate below the positioning plate. A first connecting plate and a second connecting plate are rotatably connected to the outer wall of the moving plate, and a flocculation plate is rotatably connected to the top of the first and second connecting plates.

2. The elution wastewater treatment equipment according to claim 1, characterized in that, The drive plate and the positioning plate are rotatably connected, and the top of the drive plate is rotatably connected to the outer wall of the flocculation plate.

3. The elution wastewater treatment equipment according to claim 1, characterized in that, The flocculation plate has a circular arc-shaped cross-section, and one end of the flocculation plate extends into the interior of the rotating cylinder.

4. The elution wastewater treatment equipment according to claim 1, characterized in that, The inlet end of the discharge pump and the outlet end of the sedimentation tank are sealed together, and the rotating cylinder, the jacking pipe and the sedimentation tank are interconnected.

5. The elution wastewater treatment equipment according to claim 1, characterized in that, It also includes an adjustment mechanism; the adjustment mechanism includes a positioning frame fixed to the upper surface of the sedimentation tank, an extrusion cylinder installed inside the positioning frame, an elastic piston installed inside the extrusion cylinder, a guide wheel installed on the top of the elastic piston, and a discharge pipe and a feed pipe respectively installed at the bottom of the extrusion cylinder; a rotating rod is fixed at the rotatable connection between the moving plate and the side plate, a limit plate is installed on the outer wall of the side plate and on one side of the rotating rod, a positioning sleeve is rotatably connected inside the limit plate, a cam is fixed on the outer wall of the positioning sleeve, and a positioning bolt is threadedly connected inside the positioning sleeve.

6. The elution wastewater treatment equipment according to claim 5, characterized in that, The inlet end of the feed pipe extends through the interior of the sedimentation tank, and the guide wheel and cam are in contact with each other.

7. The elution wastewater treatment equipment according to claim 5, characterized in that, The rotating rod passes through the inside of the cam and the positioning sleeve but does not contact the cam and the positioning sleeve, and the positioning bolt extends to the surface of the rotating rod.

8. The elution wastewater treatment equipment according to claim 7, characterized in that, A positioning seat is fixed on the upper surface of the jacking pipe and located on one side of the rotating cylinder. A worm is connected to the keyway at the shaft of the drive pulley, and a worm wheel is fixed on the outer wall of the rotating cylinder. The worm is rotatably connected to the positioning seat, and the worm and the worm wheel mesh with each other.

9. A process for the resource recovery of arsenic-alkali slag, characterized in that, The arsenic-alkali residue resource recovery process includes a washing wastewater treatment device as described in any one of claims 1-8. Includes the following steps: S1: Selective oxidative elution of arsenic; arsenic-containing alkaline residue is mixed with an acidic solution containing a composite oxidant in a specific ratio and oxidized under low-temperature conditions. The composite oxidant is composed of persulfate and organic acid. Persulfate acts as a strong oxidant, efficiently oxidizing the more toxic trivalent arsenic to pentavalent arsenic under acidic conditions, generating water-soluble arsenic acid. Simultaneously, the organic acid forms a stable complex with arsenic acid through its carboxyl groups, further enhancing the solubility of arsenic and selectively inhibiting the dissolution of antimony, avoiding co-dissolution of arsenic and antimony. After the reaction, solid-liquid separation is performed by centrifugation or pressure filtration to obtain a high-arsenic-concentration eluent and a low-arsenic-residue solid residue. S2: Targeted chelation elution of antimony; The solid residue separated in S1 is mixed with an acidic solution containing iron salt and a chelating agent, and reacted under ultrasonic assistance. Ferric hydroxide colloid is generated by hydrolysis, which effectively adsorbs silicate components in the residue, inhibits the formation of silica gel, and prevents it from encapsulating antimony. The chelating agent forms a stable water-soluble complex with pentavalent antimony through the coordination of hydroxyl and carboxyl groups, achieving efficient dissolution of antimony. After the reaction, the antimony-rich eluent and the final harmless residue are obtained by filtration or sedimentation. S3: Arsenic recovery: Sulfidating agent is introduced into the arsenic-rich eluent, and high-purity arsenic sulfide solid is generated through sulfidation precipitation reaction. After washing and drying, it can be directly recovered as an arsenic product. Antimony recovery: Antimony is recovered from the antimony-rich eluent by electrodeposition or chemical precipitation. Electrodeposition directly precipitates metallic antimony on the cathode surface by adjusting the current density and electrolyte pH. Chemical precipitation generates sodium pyroantimonate or antimony oxide by adding an alkaline precipitant. S4: The eluted wastewater is neutralized, filtered, and adsorbed by activated carbon to remove residual acid, heavy metal ions, and organic matter. It is then reused in the arsenic elution section of S1 to form a closed-loop system, achieving near-zero wastewater discharge. The elution wastewater needs to be neutralized and flocculated in a rotary drum and finally settled in a sedimentation tank. The discharge pump discharges the solid flocculent solids. The treated wastewater in the sedimentation tank can be recycled or discharged.

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