Aluminum ash wet leaching solution treatment system

Abstract

The utility model relates to a wet-process aluminum ash leaching liquid treatment system, comprising: a pretreatment unit, a primary treatment unit, a solid-liquid separation unit, a secondary treatment unit, a qualified water unit and an evaporation crystallization unit, wherein the pretreatment unit is connected to the primary treatment unit and the secondary treatment unit respectively, the solid-liquid separation unit is connected to the primary treatment unit and the secondary treatment unit respectively, and the qualified water unit is connected to the secondary treatment unit and the evaporation crystallization unit respectively. The aluminum ash wet-process leaching liquid treatment system provided by the application avoids corrosion and scaling of the evaporation crystallizer and prolongs the continuous service life of the evaporation crystallizer.

Description

Technical Field

[0001] The utility model relates to the technical field of waste treatment, in particular to an aluminum ash wet leaching liquid treatment system. Background Art

[0002] The "National List of Hazardous Wastes" (2021 edition) defines aluminum ash as hazardous waste. Improper disposal of aluminum ash will cause great harm to the growth of animals and plants and the human body, destroy the ecological environment, and affect the ecological balance. Aluminum ash wet leachate is an aqueous solution after solid-liquid separation of the slurry after the hydrolysis reaction of aluminum ash. The leachate contains not only water-soluble salts such as sodium chloride and potassium chloride, but also complex components such as fluoride, sulfide, and ammonia water. After treatment, the aluminum ash leachate enters the evaporation crystallization system for further resource utilization after evaporation and crystallization.

[0003] Patent CN202210799363.0 provides a secondary aluminum ash treatment method for enhanced denitrification and desalination. The method uses an alkali and acid combined sorting method to enhance the aluminum ash denitrification and desalination process. In the patent, after the solid-liquid separation of the aluminum ash slurry, the liquid is directly evaporated and crystallized after adding a pH regulator to obtain a mixed salt, and no technical method for leachate treatment is proposed. Patent CN202310648652.5 effectively removes fluoride from the aluminum ash by multi-level treatment of the secondary aluminum ash, and obtains high value-added by-products at the same time. The concentrated brine after washing the aluminum ash slurry directly enters the MVR evaporator, and is evaporated and concentrated to obtain a raw material for aluminum refining agent. No treatment method for defluorination and impurity removal of the concentrated brine after washing is proposed. Patent CN202211332425.3 slurries the aluminum ash and then washes and desalinates it to obtain a water wash and filter residue. The water wash is only added with calcium chloride for defluorination and then enters the multi-effect evaporator for evaporation to obtain a composite salt.

[0004] At present, the leachate after solid-liquid separation in wet treatment of aluminum ash is mostly directly evaporated and crystallized or only defluorinated by adding fluorine-fixing agent calcium chloride before entering the evaporation and crystallization system. Although the crystallization of some salt components can be achieved, there are problems such as complex crystallized salt composition that cannot be recycled, severe corrosion of fluoride ions to the evaporation crystallizer, calcium ions easily causing scaling of the evaporation crystallizer, severe ammonia escape from the evaporation crystallization system, and poor working environment. Therefore, improvements are needed. Utility Model Content

[0005] In view of this, the utility model provides an aluminum ash wet leaching liquid processing system.

[0006] Specifically, the utility model is realized by the following technical solutions:

[0007] According to a first aspect of the utility model, there is provided an aluminum ash wet leaching liquid treatment system, comprising: a pretreatment unit, a primary treatment unit, a solid-liquid separation unit, a secondary treatment unit, a qualified water unit and an evaporation crystallization unit, wherein the pretreatment unit is connected to the primary treatment unit and the secondary treatment unit, respectively, the solid-liquid separation unit is connected to the primary treatment unit and the secondary treatment unit, respectively, and the qualified water unit is connected to the secondary treatment unit and the evaporation crystallization unit, respectively.

[0008] Optionally, the pretreatment unit comprises: a conditioning tank, in which a liquid level meter and a pH meter are provided.

[0009] Optionally, the pretreatment unit further comprises: a deammoniation tank, the deammoniation tank is connected to the conditioning tank, and a pH meter is provided in the deammoniation tank.

[0010] Optionally, the pretreatment unit further comprises: a regulating tank, the regulating tank is connected to the deammoniation tank, and a pH meter and a mechanical agitator are provided in the regulating tank.

[0011] Optionally, the primary treatment unit includes: a primary reaction tank, the primary reaction tank is connected to the regulating tank in the pretreatment unit, and the primary reaction tank is provided with a pH meter and a mechanical stirrer.

[0012] Optionally, the primary treatment unit further includes: a primary sedimentation tank, the primary sedimentation tank is connected to the primary reaction tank, and a liquid level meter and a mechanical agitator are provided in the primary sedimentation tank.

[0013] Optionally, the secondary treatment unit includes: a secondary reaction tank, and the secondary reaction tank is connected to the solid-liquid separation unit.

[0014] Optionally, the secondary treatment unit further includes: a secondary sedimentation tank, the secondary sedimentation tank is connected to the secondary reaction tank, and the secondary sedimentation tank is connected to the primary reaction tank in the primary treatment unit through an underflow pump.

[0015] Optionally, the qualified water unit includes: an evaporation regulating tank, the evaporation regulating tank is connected to the secondary sedimentation tank in the secondary treatment unit, and a pH meter is provided in the evaporation regulating tank.

[0016] Optionally, the qualified water unit further includes: an evaporation buffer tank, the evaporation buffer tank is connected to the evaporation regulating tank, and a liquid level meter and a pH meter are provided in the evaporation buffer tank.

[0017] The technical solution provided by the utility model brings at least the following beneficial effects:

[0018] The aluminum ash wet leaching liquid treatment system provided in the present application avoids corrosion and scaling of the evaporation crystallizer and prolongs the continuous service life of the evaporation crystallizer. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The accompanying drawings herein are incorporated in and constitute a part of the specification, illustrate embodiments consistent with the present utility model, and together with the description, are used to explain the principles of the present utility model.

[0020] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or related technical descriptions are briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0021] Figure 1 A schematic structural diagram of an aluminum ash wet leaching liquid treatment system provided in an embodiment of the utility model. DETAILED DESCRIPTION

[0022] In order to make the purpose, technical solution and advantages of the embodiment of the utility model clearer, the technical solution in the embodiment of the utility model will be clearly and completely described below in conjunction with the drawings in the embodiment of the utility model. Obviously, the described embodiment is a part of the embodiment of the utility model, not all of the embodiments. Based on the embodiment of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0023] Figure 1 A wet-process aluminum ash leaching liquid treatment system suitable for an embodiment of the utility model is schematically shown.

[0024] Reference Figure 1 As shown, the present application provides an aluminum ash wet leaching liquid treatment system, including: a pretreatment unit, a primary treatment unit, a solid-liquid separation unit 301, a secondary treatment unit, a qualified water unit and an evaporation crystallization unit 601, wherein the pretreatment unit is connected to the primary treatment unit and the secondary treatment unit, respectively, the solid-liquid separation unit 301 is connected to the primary treatment unit and the secondary treatment unit, respectively, and the qualified water unit is connected to the secondary treatment unit and the evaporation crystallization unit 601, respectively.

[0025] In the embodiment of the present application, the aluminum ash leachate is pre-treated by the pre-treatment unit, and then treated by the primary treatment unit and then treated by the solid-liquid separation unit 301 for solid-liquid separation. The secondary treatment unit treats the solution again and then enters the qualified water unit and the evaporation crystallization unit 601 respectively. The qualified water unit treats the solution to obtain qualified water, and the evaporation crystallization unit 601 treats the solution to obtain evaporation crystals. The composite salt 701 and the evaporated condensed water 702 are both discharged from the evaporation crystallization unit 601.

[0026] Exemplarily, the pretreatment unit comprises: a conditioning tank 101 , in which a liquid level meter 11 and a pH meter 12 are provided.

[0027] In the embodiment of the present application, the tempering tank 101 is used to collect aluminum ash leachate, which is a solution of aluminum ash wet slurry after solid-liquid separation. The liquid level meter 11 is used to detect the volume of the aluminum ash leachate, and the pH meter 12 is used to detect the pH value of the aluminum ash leachate.

[0028] Exemplarily, the pretreatment unit further includes: a deammoniation tank 102 , wherein the deammoniation tank 102 is connected to the conditioning tank 101 , and a pH meter 12 is disposed in the deammoniation tank 102 .

[0029] In the embodiment of the present application, the deamination tank 102 is used to deaminize the aluminum ash leaching solution in the tempering tank 101, and the pH meter 12 is used to detect the pH value of the liquid in the deamination tank 102. The deamination tank 102 adopts a steam heating deamination method, a compressed air aeration deamination method or a mechanical stirring deamination method.

[0030] Exemplarily, the pretreatment unit further includes: a regulating tank 103 , wherein the regulating tank 103 is connected to the deammoniation tank 102 , and a pH meter 12 and a mechanical stirrer 13 are provided in the regulating tank 103 .

[0031] In an embodiment of the present application, the regulating tank 103 is used to add a pH adjuster and a forced oxidant, the pH adjuster includes one or more of hydrochloric acid, sulfuric acid, ferric chloride, and polyaluminium chloride, and the forced oxidant includes one or more of hydrogen peroxide, potassium permanganate, and peracetic acid.

[0032] Exemplarily, the primary treatment unit includes: a primary reaction tank 201, the primary reaction tank 201 is connected to the regulating tank 103 in the pretreatment unit, and the primary reaction tank 201 is provided with a pH meter 12 and a mechanical stirrer 13.

[0033] In an embodiment of the present application, a calcium-based purifier and a coagulant are added to the primary reaction tank 201, wherein the calcium-based purifier includes one or more of calcium chloride, calcium oxide, calcium hydroxide, and calcium disodium ethylenediaminetetraacetate; the coagulant includes one or more of ferric chloride, polyaluminum chloride, polyaluminum ferric chloride, and polyacrylamide.

[0034] Exemplarily, the primary treatment unit further includes: a primary sedimentation tank 202 , wherein the primary sedimentation tank 202 is connected to the primary reaction tank 201 , and a liquid level meter 11 and a mechanical agitator 13 are provided in the primary sedimentation tank 202 .

[0035] In the embodiment of the present application, the primary sedimentation tank 202 is used to precipitate the solution after the reaction, the liquid level meter 11 is used to detect the liquid level of the solution, and the mechanical stirrer 13 is used to stir the solution. The primary sedimentation tank 202 is connected to the solid-liquid separation unit 301 through the sludge pump 3011.

[0036] Exemplarily, the secondary treatment unit includes: a secondary reaction tank 401 , and the secondary reaction tank 401 is connected to the solid-liquid separation unit 301 .

[0037] In the embodiment of the present application, a deep purifier is added to the secondary reaction tank 401, including one or more of calcium chloride, ferric chloride, sodium carbonate, polyaluminium chloride and polyacrylamide.

[0038] Exemplarily, the secondary treatment unit further includes: a secondary sedimentation tank 402, wherein the secondary sedimentation tank 402 is connected to the secondary reaction tank 401, and the secondary sedimentation tank 402 is connected to the primary reaction tank 201 in the primary treatment unit via an underflow pump 4011.

[0039] In the embodiment of the present application, the secondary sedimentation tank 402 is used to precipitate the solution after the reaction.

[0040] Exemplarily, the qualified water unit includes: an evaporation regulating tank 501, the evaporation regulating tank 501 is connected to the secondary sedimentation tank 402 in the secondary treatment unit, and a pH meter 12 is provided in the evaporation regulating tank 501.

[0041] In the embodiment of the present application, hydrochloric acid is added into the evaporation regulating tank 501 .

[0042] Exemplarily, the qualified water unit further includes: an evaporation buffer tank 502 , wherein the evaporation buffer tank 502 is connected to the evaporation regulating tank 501 , and a liquid level meter 11 and a pH meter 12 are provided in the evaporation buffer tank 502 .

[0043] In the embodiment of the present application, sodium hydroxide is added to the evaporation buffer tank 502. The evaporation crystallization unit 601 is connected to the evaporation buffer tank 502 of the qualified water unit via the evaporation water pump 6011.

[0044] Example 1

[0045] The present application provides a wet-process leachate treatment system for aluminum ash, including a pretreatment unit, a primary treatment unit, a solid-liquid separation unit 301, a secondary treatment unit, a qualified water unit, and an evaporation crystallization unit 601. After the aluminum ash wet-process slurry is solid-liquid separated, the leachate with a fluoride ion content of 630 mg / L enters the conditioning tank 101 for mixing, the leachate in the conditioning tank 101 enters the deammonification tank 102, the deammonification tank 102 uses steam to blow off the ammonia component in the solution, the solution enters the regulating tank 103 from the deammonification tank 102, hydrochloric acid and ferric chloride are added to the regulating tank 103 in sequence; the leachate enters the primary reaction tank 201 from the regulating tank 103, calcium chloride, calcium oxide, ferric chloride, polyaluminum ferric chloride and polyacrylamide are added to the primary reaction tank 201 in sequence, and after being stirred evenly, it flows into the primary sedimentation tank 202 by gravity; the sludge at the bottom of the primary sedimentation tank 202 is pumped to the plate and frame filter press by the sludge pump, and the clear liquid of the primary sedimentation tank 202 and the plate and frame filter press The filtrate from the machine enters the secondary reaction tank 401, and calcium chloride, ferric chloride, sodium carbonate, polyaluminium chloride and polyacrylamide are added to the secondary reaction tank 401 in sequence. The liquid from the secondary reaction tank 401 flows by gravity to the secondary sedimentation tank 402. The supernatant from the secondary sedimentation tank 402 enters the evaporation regulating tank 501, and the bottom slurry is sent to the regulating tank 103 for circulation treatment through the underflow pump 4011; hydrochloric acid is added to the evaporation regulating tank 501, and sodium hydroxide is added to the evaporation buffer tank 502, and the fluoride ion content in the water is 4.55 mg / L and the calcium ion content is 9.8 mg / L; the solution from the evaporation buffer tank 502 is sent to the evaporation crystallizer through the evaporation water pump for salt crystallization, and the salt is used as a refining agent product for aluminium, and the evaporated crystallization water is returned to the aluminium ash for leaching and recycling.

[0046] Example 2

[0047] The present application provides a wet-process leachate treatment system for aluminum ash, including a pretreatment unit, a primary treatment unit, a solid-liquid separation unit 301, a secondary treatment unit, a qualified water unit, and an evaporation crystallization unit 601. After the aluminum ash wet-process slurry is solid-liquid separated, the leachate with a fluoride ion content of 413 mg / L enters the tempering tank 101 for mixing, the leachate in the tempering tank 101 enters the deammoniation tank 102, the deammoniation tank 102 uses steam to blow off the ammonia component in the solution, the solution enters the regulating tank 103 from the deammoniation tank 102, hydrochloric acid and hydrogen peroxide are added to the regulating tank 103 in sequence; the leachate enters the primary reaction tank 201 from the regulating tank 103, calcium chloride, calcium disodium ethylenediaminetetraacetic acid, ferric chloride, polyaluminum chloride and polyacrylamide are added to the primary reaction tank 201 in sequence, and after being stirred evenly, it flows into the primary sedimentation tank 202 by gravity; the sludge at the bottom of the primary sedimentation tank 202 is pumped to the plate and frame filter press by the sludge pump, and the primary sedimentation tank The clear liquid 202 and the filtrate of the plate and frame filter press both enter the secondary reaction tank 401, and calcium chloride, sodium carbonate and polyaluminium chloride are added to the secondary reaction tank 401 in sequence. The liquid of the secondary reaction tank 401 flows by gravity to the secondary sedimentation tank 402, and the supernatant of the secondary sedimentation tank 402 enters the evaporation regulating tank 501, and the bottom slurry is pumped to the regulating tank 103 for circulation treatment through the underflow pump; hydrochloric acid is added to the evaporation regulating tank 501, and sodium hydroxide is added to the evaporation buffer tank 502, and the fluoride ion content in the water is 3.7 mg / L and the calcium ion content is 7.2 mg / L; the solution in the evaporation buffer tank 502 is pumped to the evaporation crystallizer for salt crystallization through the evaporation water pump, and the salt is used as a refining agent product for aluminum, and the evaporated crystallization water is returned to the aluminum ash for leaching and recycling.

[0048] The aluminum ash wet leaching liquid treatment system provided in the present application avoids corrosion and scaling of the evaporation crystallizer and prolongs the continuous service life of the evaporation crystallizer.

[0049] It should be noted that, in the present application, the terms "upper", "lower", "left", "right", "front", "back", "top", "bottom", "inner", "outer", "vertical", "horizontal", "lateral", "longitudinal" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings. These terms are mainly used to better describe the present application and its embodiments, and are not used to limit the indicated devices, elements or components to have a specific orientation, or to be constructed and operated in a specific orientation.

[0050] In addition, some of the above terms may be used to express other meanings in addition to indicating orientation or positional relationship. For example, the term "on" may also be used to express a certain dependency or connection relationship in some cases. For those of ordinary skill in the art, the specific meanings of these terms in this application can be understood according to specific circumstances.

[0051] In addition, the terms "installed", "set", "provided with", "connected", and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral structure; it can be a mechanical connection, or an electrical connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be an internal connection between two devices, elements, or components. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0052] In addition, the terms "first", "second", etc. are mainly used to distinguish different devices, elements or components (the specific types and structures may be the same or different), and are not used to indicate or imply the relative importance and quantity of the indicated devices, elements or components. Unless otherwise specified, "plurality" means two or more.

[0053] The above description is only a specific embodiment of the present invention, so that those skilled in the art can understand or implement the present invention. Various modifications to these embodiments will be obvious to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but should conform to the widest scope consistent with the principles and novel features applied herein.

Claims

1. A wet leaching solution treatment system for aluminum ash, characterized in that: include: A pretreatment unit, a primary treatment unit, a solid-liquid separation unit, a secondary treatment unit, a qualified water unit and an evaporation crystallization unit, wherein the pretreatment unit is connected to the primary treatment unit and the secondary treatment unit respectively, the solid-liquid separation unit is connected to the primary treatment unit and the secondary treatment unit respectively, and the qualified water unit is connected to the secondary treatment unit and the evaporation crystallization unit respectively.

2. The aluminum ash wet leaching solution treatment system according to claim 1 is characterized in that: The pretreatment unit comprises: a conditioning tank, in which a liquid level meter and a pH meter are arranged.

3. The aluminum ash wet leaching solution treatment system according to claim 2 is characterized in that: The pretreatment unit further comprises: a deammoniation tank, the deammoniation tank is connected to the conditioning tank, and a pH meter is arranged in the deammoniation tank.

4. The aluminum ash wet leaching solution treatment system according to claim 3 is characterized in that: The pretreatment unit also includes: a regulating tank, which is connected to the deammoniation tank and is provided with a pH meter and a mechanical stirrer.

5. The aluminum ash wet leaching solution treatment system according to claim 1, characterized in that: The primary treatment unit comprises: a primary reaction tank, which is connected to the regulating tank in the pretreatment unit, and is provided with a pH meter and a mechanical stirrer.

6. The aluminum ash wet leaching solution treatment system according to claim 5, characterized in that: The primary treatment unit further comprises: a primary sedimentation tank, the primary sedimentation tank is connected to the primary reaction tank, and a liquid level meter and a mechanical agitator are arranged in the primary sedimentation tank.

7. The aluminum ash wet leaching solution treatment system according to claim 1, characterized in that: The secondary treatment unit comprises: a secondary reaction tank, and the secondary reaction tank is connected to the solid-liquid separation unit.

8. The aluminum ash wet leaching solution treatment system according to claim 7, characterized in that: The secondary treatment unit further comprises: a secondary sedimentation tank, the secondary sedimentation tank is connected to the secondary reaction tank, and the secondary sedimentation tank is connected to the primary reaction tank in the primary treatment unit via an underflow pump.

9. The aluminum ash wet leaching solution treatment system according to claim 8, characterized in that: The qualified water unit comprises: an evaporation regulating tank, the evaporation regulating tank is connected to the secondary sedimentation tank in the secondary treatment unit, and a pH meter is arranged in the evaporation regulating tank.

10. The aluminum ash wet leaching solution treatment system according to claim 9, characterized in that: The qualified water unit further comprises: an evaporation buffer tank, the evaporation buffer tank is connected to the evaporation regulating tank, and a liquid level meter and a pH meter are arranged in the evaporation buffer tank.

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