Method and system for recycling phenol-containing organic phosphoric acid waste liquid

Abstract

The invention provides a phenol-containing organic phosphoric acid waste liquid recovery treatment method and system.The recovery treatment method comprises the steps that to-be-treated phenol-containing organic phosphoric acid waste liquid and an extraction agent are mixed for extraction treatment, an extraction phase and a raffinate phase are obtained, and the raffinate phase comprises nitrogen-containing organic cations and phosphate radicals; the extraction phase is subjected to agent removal treatment, and the phenolic compound is obtained; carrying out oxidation treatment on the raffinate phase by utilizing an oxidizing agent, and degrading nitrogen-containing organic cations to obtain a gas-phase component and a liquid-phase component; and collecting a liquid-phase component to obtain recyclable phosphoric acid. The recycling treatment method provided by the invention can be used for efficiently recycling phenolic organic matters and high-purity phosphoric acid in the phosphoric acid waste liquid, so that the treatment cost is reduced, and cyclic utilization of resources is realized.

Description

Technical Field

[0001] The present application relates to the field of organic phosphoric acid waste liquid treatment, and in particular to a method and system for recovering and treating phenol-containing organic phosphoric acid waste liquid. Background Art

[0002] Phenol-containing organic phosphoric acid waste liquid mainly comes from industrial sectors such as coal chemical industry, petrochemical industry, and coking industry. Traditional waste phosphoric acid treatment mostly adopts incineration or neutralization method, which leads to waste of phosphoric acid resources, ineffective recovery of organic matter, high treatment cost, and easy to cause secondary pollution.

[0003] Therefore, a new processing method is urgently needed to solve the above problems. Summary of the Invention

[0004] The embodiments of the present application provide a method and system for recycling and treating phenol-containing organic phosphoric acid waste liquid, which can efficiently recover phenolic organic matter and high-purity phosphoric acid in the phosphoric acid waste liquid, reduce processing costs, and achieve resource recycling.

[0005] In a first aspect, an embodiment of the present application provides a method for recovering and treating phenol-containing organic phosphoric acid waste liquid, comprising: mixing the phenol-containing organic phosphoric acid waste liquid to be treated with an extractant for extraction treatment to obtain an extract phase and a raffinate phase, wherein the raffinate phase includes nitrogen-containing organic cations and phosphate groups; removing the extract phase from the extract phase to obtain phenolic compounds; oxidizing the raffinate phase with an oxidant to degrade the nitrogen-containing organic cations to obtain a gas phase component and a liquid phase component; and collecting the liquid phase component to obtain reusable phosphoric acid.

[0006] According to an embodiment of the first aspect of the present application, the phenol-containing organic phosphoric acid waste liquid to be treated is mixed with an extractant for extraction treatment to obtain an extraction phase and a raffinate phase, which includes the following sub-steps: under temperature conditions of 50°C to 100°C, the phenol-containing organic phosphoric acid waste liquid is mixed with the extractant to obtain a mixed liquid; the mixed liquid is stirred for a first preset time, allowed to stand and separated into layers, and then separated to obtain an extraction phase and a raffinate phase; each sub-step of the extraction treatment is cyclically performed at least once.

[0007] According to an embodiment of the first aspect of the present application, the extractant includes one or more of alkane compounds, aromatic compounds, ether compounds, ester compounds and ketone compounds.

[0008] According to an embodiment of the first aspect of the present application, the mass ratio of the phenol-containing organic phosphoric acid waste liquid to the extractant is (2~6):1.

[0009] According to an embodiment of the first aspect of the present application, the step of mixing and oxidizing the raffinate phase with an oxidant to obtain a gas phase component and a liquid phase component includes: Under the temperature condition of 120° C. to 160° C., an oxidant is introduced into the raffinate phase, and the oxidation reaction is continued for a second preset time.

[0010] According to an embodiment of the first aspect of the present application, the oxidant includes one or more of hydrogen peroxide, hydrogen peroxide, oxygen and ozone; optionally, the concentration of hydrogen peroxide is ≥25%.

[0011] According to an embodiment of the first aspect of the present application, it also includes: absorbing and collecting gas phase components, where the gas phase components include carbon dioxide and nitrogen dioxide.

[0012] According to an embodiment of the first aspect of the present application, the step of absorbing and collecting the gas phase components includes: absorbing the gas phase components through multi-stage clean water to obtain a first absorption liquid and residual gas; absorbing the residual gas through multi-stage alkaline solution to obtain a second absorption liquid.

[0013] According to an embodiment of the first aspect of the present application, the step of collecting liquid phase components to obtain reusable phosphoric acid includes: collecting liquid phase components; and concentrating the liquid phase components to obtain reusable phosphoric acid.

[0014] According to an embodiment of the first aspect of the present application, the phenol-containing organic phosphoric acid waste liquid includes the following components by mass fraction: 2-4% water, 8-10% phenolic compounds, 12-14% alkaline nitrogen compounds, and 74-78% phosphate.

[0015] In a second aspect, an embodiment of the present application provides a system for recovering and treating phenol-containing organic phosphoric acid waste liquid, comprising: an extraction device for receiving phenol-containing organic phosphoric acid waste liquid and an extractant, extracting phenolic compounds in the phenol-containing organic phosphoric acid waste liquid by the extractant, and separating them into an extract phase and a raffinate phase; a separation device connected to the extraction device, for receiving the extract phase and performing a desolventizing treatment on the extract phase; an oxidation device connected to the extraction device, for receiving the raffinate phase and an oxidant for an oxidation reaction; and a gas absorption device connected to the oxidation device, for receiving and absorbing and collecting the gas phase components produced by the oxidation reaction.

[0016] According to an embodiment of the second aspect of the present application, a concentrating device is further included, which is connected to the oxidation device and is used to receive the liquid phase components after the oxidation reaction and concentrate the liquid phase components.

[0017] The method for recovering and treating phenol-containing organic phosphoric acid waste liquid in the embodiment of the present application selectively separates phenols through an extractant and oxidizes and degrades nitrogen-containing organic cations through an oxidant. The remaining phosphoric acid can be recycled, thereby avoiding the generation of solid waste. At the same time, phenolic organic matter and high-purity phosphoric acid in the waste phosphoric acid are efficiently recovered, reducing processing costs and realizing resource recycling. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0019] Figure 1 A flow chart of a method for recovering and treating phenol-containing organic phosphoric acid waste liquid provided in an embodiment of the present application; Figure 2 for Figure 1 Specific flow chart of step S100; Figure 3 for Figure 1 Specific flow chart of step S400; Figure 4 This is a schematic diagram of the connection of a system for recovering and treating phenol-containing organic phosphoric acid waste liquid provided in an embodiment of the present application.

[0020] Reference numerals: 100. Extraction device; 200. Separation device; 300. Oxidation device; 400. Gas absorption device; 401. Carbon dioxide absorption device; 402. Nitrogen dioxide absorption device; 500. Concentration device. DETAILED DESCRIPTION

[0021] The following embodiments of the technical solution of the present application will be described in detail with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present application and are therefore only examples and are not intended to limit the scope of protection of the present application.

[0022] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" and any variations thereof in the specification and claims of this application and the above-mentioned figure descriptions are intended to cover non-exclusive inclusions.

[0023] In the description of the embodiments of this application, the technical terms "first" and "second" are used only to distinguish different objects and should not be understood to indicate or imply relative importance or implicitly specify the quantity, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, the meaning of "plurality" is more than two, unless otherwise clearly and specifically defined.

[0024] References herein to "embodiments" mean that a particular feature, structure, or characteristic described in connection with the embodiments may be included in at least one embodiment of the present application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0025] In the description of the embodiments of this application, the term "and / or" is simply a description of the association relationship between associated objects, indicating that three relationships can exist. For example, A and / or B can represent the following three situations: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in this document generally indicates that the associated objects are in an "or" relationship.

[0026] In the description of the embodiments of the present application, the term "multiple" refers to more than two (including two). Similarly, "multiple groups" refers to more than two groups (including two groups), and "multiple pieces" refers to more than two pieces (including two pieces).

[0027] In the description of the embodiments of the present application, the technical terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the embodiments of the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the embodiments of the present application.

[0028] In the description of the embodiments of the present application, unless otherwise expressly specified or limited, technical terms such as "installed," "connected," "connected," and "fixed" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integration; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; internal connections between two components or interactions between two components. Those skilled in the art can understand the specific meanings of the above terms in the embodiments of the present application based on specific circumstances.

[0029] In chemical production processes, such as the production of phenolic compounds from coal-based conversion, phosphoric acid is widely used because it has strong pertinence and good removal effect in removing alkaline nitrogen compounds from phenolic compounds. However, it also produces a large amount of high-concentration organic phosphoric acid waste liquid containing phenolic organic matter. The inventors of the present application have noticed that the neutralization method is currently a more common treatment method for the treatment of such organic phosphoric acid waste liquid. However, the neutralization method has many drawbacks. It will produce a large amount of solid waste, which will in turn cause secondary pollution problems. At the same time, the method cannot effectively degrade the organic matter in the waste phosphoric acid, which is not conducive to resource recycling and environmental protection. In addition, some existing treatment processes often need to be carried out under high temperature conditions, which not only has high energy costs, but also has complex equipment requirements and high treatment costs, making it difficult to achieve efficient treatment and resource recycling of phenol-containing organic phosphoric acid waste liquid.

[0030] In view of the above problems, the embodiments of the present application provide a method and system for recycling and treating phenol-containing organic phosphoric acid waste liquid, which can efficiently recover phenolic organic matter and high-purity phosphoric acid in the phosphoric acid waste liquid, reduce processing costs, and achieve resource recycling.

[0031] First, see Figure 1 The present invention provides a method for recovering and treating phenol-containing organic phosphoric acid waste liquid, comprising: S100: mixing the phenol-containing organic phosphoric acid waste liquid to be treated with an extractant for extraction treatment to obtain an extract phase and a raffinate phase, wherein the raffinate phase includes nitrogen-containing organic cations and phosphate; S200: removing the agent from the extract phase to obtain phenolic compounds; S300: oxidizing the raffinate phase with an oxidant to degrade nitrogen-containing organic cations to obtain a gas phase component and a liquid phase component; S400: collecting liquid components to obtain reusable phosphoric acid.

[0032] In step S100, the phenol-containing organic phosphoric acid waste liquid to be treated is mixed with an extractant for extraction treatment. The extractant can selectively combine with phenolic compounds, thereby separating the phenolic compounds from the phenol-containing organic phosphoric acid waste liquid and entering the extraction phase, thereby achieving preliminary separation of phenols from other components.

[0033] In the examples of the present application, the extractant must be highly selective for phenolic compounds, and the extractant and phenols can be bound together through specific intermolecular forces. For example, an extractant containing polar groups can generate strong binding forces with the hydroxyl groups of phenols through hydrogen bonding and dipole-dipole interactions, while having weaker binding forces with other components in the phosphoric acid wastewater, such as inorganic acid radicals.

[0034] In some embodiments, the extractant includes one or more of alkane compounds, aromatic compounds, ether compounds, ester compounds, and ketone compounds.

[0035] During the extraction process, alkanes can act as diluents to adjust the physical properties of the extraction system, reduce system viscosity, and promote mixing and mass transfer between the two phases. Aromatic hydrocarbons contain benzene ring structures, which have a certain electron cloud density and polarity. Their π-π conjugated system can generate π-π interactions with the benzene rings of phenols. At the same time, weak hydrogen bonding or van der Waals forces may exist between the hydrogen atoms on the benzene rings and the phenolic hydroxyl groups, giving aromatic hydrocarbons a certain affinity for phenols. Ether compounds contain ether bonds in their molecules, and the lone pair of electrons on the oxygen atoms gives them a certain polarity, which can form hydrogen bonds with the hydroxyl groups of phenols, promoting the transfer of phenols from phenol-containing organophosphate waste liquids to the ether phase. Ester compounds contain ester groups, and their carbonyl oxygen atoms have strong electronegativity, which can form hydrogen bonds or dipole-dipole interactions with the hydroxyl groups of phenols. Through intermolecular forces with phenols, phenols can be extracted into the organic phase.

[0036] Illustratively, the alkane compound may be heptane; the aromatic compound may be toluene and / or xylene; the ether compound may be diisopropyl ether and / or methyl tert-amyl ether; the ester compound may be butyl acetate and / or dimethyl carbonate; and the ketone compound may be methyl propyl ketone and / or methyl isopropyl ketone.

[0037] When the extractants are two or more of the above-mentioned specific options, the embodiments of the present application do not have any special restrictions on the ratio of the above-mentioned specific substances, and they can be mixed in any ratio.

[0038] In addition, since the extraction process in the embodiment of the present application may be carried out at a relatively high temperature, the extraction agent is preferably a solvent with a boiling point of 60 o C~120 o C of the extractant; at the same time, the boiling point of the extractant is within the above moderate range to facilitate subsequent deagent treatment.

[0039] For example, the boiling point of the extractant may be 60 o C. 65 o C. 70 o C. 75 o C. 80 o C. 85 o C. 90 o C. 95 o C. 100 o C. 105 o C. 110 o C. 115 o C. 120 o C or the interval consisting of any two of the above values.

[0040] In some embodiments, see Figure 2 The method of mixing the phenol-containing organic phosphoric acid waste liquid to be treated with an extractant to perform extraction treatment to obtain an extract phase and a raffinate phase comprises the following sub-steps: S101: mixing phenol-containing organic phosphoric acid waste liquid with an extractant at a temperature of 50° C. to obtain a mixed liquid; S102: stirring the mixed liquid for a first preset time, allowing it to stand for stratification, and then separating it to obtain an extract phase and a raffinate phase.

[0041] In the examples of the present application, a phenol-containing organic phosphoric acid waste liquid is mixed with an extractant at a temperature of 50°C to 100°C to obtain a mixed liquid. From the perspective of molecular motion, increasing the temperature can increase the thermal motion rate of the molecules, thereby increasing the frequency of collisions between the phenol-containing organic phosphoric acid waste liquid and the extractant molecules, thereby accelerating the mass transfer process of phenolic compounds from the waste liquid phase to the extractant phase. At lower temperatures, molecular motion is slow, mass transfer efficiency is low, and phenol extraction is insufficient. On the other hand, when the temperature is too high, it may lead to increased volatilization losses of the extractant, resulting in increased costs and environmental pollution.

[0042] The treatment method in the embodiment of the present application can especially cope with the situation of high phosphoric acid content. When the phosphoric acid concentration is high, the viscosity of the waste liquid is large. By mixing the phenol-containing organic phosphoric acid waste liquid with the extractant at a temperature of 50°C to 100°C, a higher mass transfer efficiency can be achieved.

[0043] For example, the temperature of the mixed solution obtained by mixing the phenol-containing organic phosphoric acid waste liquid with the extractant is 50 o C. 55 o C. 60 o C. 65 o C. 70 o C. 75 o C. 80 o C. 85 o C. 90 o C. 95 o C. 100 o C or the interval consisting of any two of the above values.

[0044] The mixed liquid is stirred for a first preset time, allowed to stand and separated to obtain an extract phase and a residual phase. The stirring operation can increase the contact area of ​​the two phases and enhance the mass transfer process. By stirring, the phenol-containing organic phosphoric acid waste liquid and the extractant can be more fully mixed, so that the phenolic compounds have more opportunities to contact and combine with the extractant molecules. Excessive stirring intensity and long stirring time may cause emulsification, making it difficult to separate the two phases; insufficient stirring and too short a time will not achieve effective mass transfer. According to experimental verification, under appropriate stirring conditions, the first preset time in the embodiment of the present application can be 20~40min, which can make the phenolic compounds fully distributed in the two phases.

[0045] Exemplarily, the first preset time may be 20 min, 22 min, 24 min, 25 min, 26 min, 28 min, 30 min, 32 min, 34 min, 35 min, 36 min, 38 min, 40 min, or an interval range consisting of any two of the above values.

[0046] The static separation process utilizes the density difference between the extract and raffinate phases to naturally separate them. The static separation time must be long enough to ensure complete separation of the two phases. For example, the static separation time is 20-40 minutes, which facilitates subsequent separation of the two phases by liquid separation or other methods.

[0047] Each sub-step of the extraction process is repeated at least once. That is, after the previous extraction process, the raffinate phase obtained by separation is subjected to a further extraction process with the extractant. For example, after the first extraction process, an extract phase and a raffinate phase are obtained. The raffinate phase and the extractant are mixed at a temperature of 50°C to 100°C to obtain a mixed liquid. The mixed liquid is stirred for a first predetermined time, allowed to stand for separation, and then separated to obtain an extract phase and a raffinate phase. Exemplarily, each sub-step of the extraction process is repeated at least three times.

[0048] Circulating extraction significantly improves the extraction rate of phenolic compounds. Because a single extraction process is limited by the distribution coefficient, it is difficult to completely extract phenols from the wastewater. Circulating extraction allows the raffinate phase to be extracted again, continuously reducing the amount of residual phenols in the raffinate phase. Furthermore, multiple extraction cycles can make the entire extraction process more stable, reducing the impact of factors such as raw material composition fluctuations on the extraction effect, and ensuring the stability of the final product quality.

[0049] Phenol-containing organic phosphoric acid wastewater contains a large amount of phosphoric acid and alkaline nitrogen compounds, including pyridine, aniline, and other substances. In an acidic environment, alkaline nitrogen compounds will be converted into nitrogen-containing organic cations. Therefore, the raffinate phase contains nitrogen-containing organic cations and phosphate.

[0050] It should be noted that when selecting the extraction temperature and the type of extractant, the extraction temperature must be lower than the boiling point of the extractant.

[0051] In some embodiments, the mass ratio of the phenol-containing organic phosphoric acid waste liquid to the extractant is (2-6):1.

[0052] To maximize the transfer of phenolic compounds from phenolic organophosphoric acid wastewater to the extraction phase, it's crucial to ensure a sufficient amount of extractant to bind the phenols. Insufficient extractant can't fully extract the phenols, resulting in excessive phenolic residues in the raffinate phase, impacting phenol recovery efficiency and the purity of the subsequent phosphoric acid reuse. Excessive extractant, while maintaining a high extraction rate, increases the cost of the extractant and the energy consumption of subsequent desolventization treatments, potentially making extract phase processing more difficult.

[0053] The present embodiment comprehensively considers parameters such as extraction temperature and extraction time to achieve a mass ratio of phenol-containing organophosphoric acid waste liquid to extractant of (2-6):1. Under temperature conditions of 50°C to 100°C, this suitable mass ratio enables sufficient contact between the extractant and phenols and completes the mass transfer process within a relatively short stirring time. When combined with a cyclic extraction process, this mass ratio achieves excellent extraction results with each cycle, reducing the number of cycles and improving overall processing efficiency.

[0054] Illustratively, the mass ratio of the phenol-containing organophosphoric acid waste liquid to the extractant is 2:1, 3:1, 4:1, 5:1 or 6:1.

[0055] The recovery and treatment methods in the embodiments of the present application can treat the organophosphoric acid waste liquid generated when removing alkaline nitrogen compounds from phenolic compounds. The pH of the phenol-containing organophosphoric acid waste liquid is generally less than 2. In some embodiments, the phenol-containing organophosphoric acid waste liquid includes the following components by mass fraction: 2-4% water, 8-10% phenolic compounds, 12-14% alkaline nitrogen compounds, and 74-78% phosphate.

[0056] Illustratively, the mass fraction of phosphate in the phenol-containing organophosphoric acid waste liquid may be 74%, 75%, 76%, 77% or 78%.

[0057] For example, the mass fraction of the basic nitrogen compound in the phenol-containing organic phosphoric acid waste liquid may be 12%, 13% or 14%.

[0058] For example, the mass fraction of phenolic compounds in the phenol-containing organophosphoric acid waste liquid may be 8%, 9% or 10%.

[0059] For example, the mass fraction of water in the phenol-containing organophosphoric acid waste liquid may be 2%, 3% or 4%.

[0060] The recovery and treatment method in the embodiment of the present application can realize phosphoric acid recovery from high-concentration phosphoric acid waste liquid.

[0061] In step S200, the extract phase is subjected to a deagent treatment to obtain a phenolic compound. The embodiment of the present application uses a suitable deagent treatment process to separate the extractant from the phenolic compound, which not only efficiently recovers the phenolic compound but also enables the recycling of the extractant, thereby reducing production costs.

[0062] Specifically, distillation can be used to remove the extractant based on the boiling point difference between the extractant and the phenolic compounds. By heating the extract phase, the extractant with a lower boiling point is preferentially vaporized. The vapor is condensed to recover the extractant, while the phenolic compounds remain in the distillation apparatus. For example, when the extractant is methyl isobutyl ketone (boiling point approximately 116°C), heating the extract phase to a temperature slightly above its boiling point (e.g., 120-130°C) under appropriate vacuum causes the methyl isobutyl ketone to rapidly vaporize. After cooling in a condenser, the liquid extractant can be collected, and the remaining substance is the phenolic compound.

[0063] In order to improve the separation effect, distillation can be used to achieve more efficient separation of the extractant and phenols through multiple gas-liquid mass transfer in the distillation tower, thereby reducing the residual amount of extractant in phenols. Illustratively, the distillation apparatus may be a rectification column.

[0064] For example, during distillation, the system pressure is 20-60 kPa, the tower top temperature is 60° C.-120° C., and the reflux ratio is 10:1.

[0065] The treatment method of the present invention can also employ adsorption separation to remove the extractant. An adsorbent (such as activated carbon or molecular sieve) with high selectivity for the extractant is selected, and the extract phase is passed through an adsorption column. The extractant is adsorbed by the adsorbent, while the phenolic compounds pass through smoothly, thereby separating the extractant from the phenolic compounds. The adsorbent can then be regenerated by heating, purging, or other methods, and the extractant can be recovered.

[0066] In step S300, the raffinate phase is oxidized using an oxidant to degrade the nitrogen-containing organic cations, producing gaseous and liquid phase components. During the oxidation process, the oxidant chemically reacts with the nitrogen-containing organic cations, oxidizing and degrading them into gaseous and liquid phases, effectively removing the nitrogen-containing organic cations from the raffinate phase.

[0067] The nitrogen atoms of nitrogen-containing organic cations can form chemical bonds with other groups in the raffinate phase. Oxidation treatment, based on the principle of redox reactions, utilizes the strong oxidizing properties of the oxidant to break down the chemical bonds of the nitrogen-containing organic cations, causing their structure to break and restructure. During the oxidation process, as the oxidant is added and the reaction proceeds, the nitrogen-containing organic cations in the raffinate phase gradually degrade.

[0068] The strong oxidizing environment provided by the oxidant can remove electrons from nitrogen-containing organic cations, increasing the valence of the nitrogen element and promoting its gradual degradation into small molecules. The oxidant first reacts with the active groups on the surface of the nitrogen-containing organic cations, gradually fragmenting the macromolecular structure. These fragments are then further oxidized, breaking chemical bonds such as carbon-nitrogen and carbon-carbon bonds, generating substances such as carbon dioxide, nitrogen dioxide, water, and some small organic acids. Subsequent filtration, evaporation, and concentration of the liquid phase remove impurities such as small organic acids, resulting in high-purity, reusable phosphoric acid.

[0069] Oxidation of the raffinate phase removes nitrogen-containing organic cations, preventing them from generating solid waste or secondary pollution during the waste phosphoric acid treatment process. This treatment method thoroughly degrades nitrogen-containing organic cations, deeply purifying the waste phosphoric acid liquid and ensuring the subsequent reuse of phosphoric acid. Furthermore, the oxidation process does not require complex equipment or harsh reaction conditions and can be completed under relatively mild operating conditions, reducing equipment investment and operating costs. Furthermore, the gaseous components produced during the treatment process can be rationally utilized or harmlessly disposed of, and the phosphoric acid in the liquid phase is efficiently recovered, truly achieving resource recycling and providing significant economic and environmental benefits.

[0070] It is understandable that there is no strict order between step S200 and step S300, that is, step S200 and step S300 are both executed after S100, step S200 and step S300 can be executed synchronously, step S200 can be executed before step S300, or after step S300.

[0071] In some embodiments, the step of mixing the raffinate phase with an oxidant and oxidizing it to obtain a gas phase component and a liquid phase component includes: introducing the oxidant into the raffinate phase at a temperature of 120° C. to 160° C., and continuing the oxidation reaction for a second preset time.

[0072] The treatment method of the embodiment of the present application performs mixed oxidation under the temperature conditions of 120℃~160℃, which can improve the oxidation efficiency. Increasing the temperature can significantly increase the thermal motion rate of the molecules, greatly increase the collision frequency of the oxidant molecules with the nitrogen-containing organic cation molecules in the extract phase, effectively increase the percentage of activated molecules in the reaction, thereby accelerating the oxidation reaction rate. Within the above temperature range, the oxidation reaction can achieve the expected degradation effect in a shorter time, greatly improving the treatment efficiency. At lower temperatures, some stable chemical bonds are difficult to be effectively destroyed by the oxidant, resulting in incomplete degradation; at higher temperatures, on the one hand, excessively high temperatures will accelerate the decomposition of the oxidant, such as hydrogen peroxide will quickly decompose into water and oxygen at this temperature, reducing the effective utilization rate of the oxidant and increasing the processing cost; on the other hand, high temperature may cause phosphoric acid to decompose or volatilize, resulting in the loss of phosphoric acid, and may also trigger side reactions in the degradation process of nitrogen-containing organic cations, generating nitrogen-containing byproducts that are difficult to handle, affecting the subsequent separation and utilization of gas and liquid components.

[0073] The oxidant is introduced into the raffinate phase using common methods including bubbling and jetting. Bubbling introduces the oxidant as a gas from the bottom of the container, causing it to rise in the raffinate phase in the form of bubbles, where it fully contacts and reacts with nitrogen-containing organic cations. This method ensures uniform mixing of the oxidant and the raffinate phase. As the bubbles rise, they continuously break and renew the interface, increasing the mass transfer area and facilitating the oxidation reaction. Jetting utilizes high pressure to disperse the oxidant solution into the raffinate phase in the form of a high-speed jet, forming fine droplets. This greatly increases the contact area between the two phases and enhances the mass transfer and reaction process.

[0074] The second preset time for the oxidation reaction to continue can be determined by comprehensively considering many factors. When the concentration of nitrogen-containing organic cations is high, a longer reaction time is required to ensure their full degradation; if the nitrogen-containing organic cations have a complex structure and high stability, more reaction time is also required to destroy their chemical bonds. Secondly, the type and amount of the oxidant will also affect the second preset time. For example, when ozone with strong oxidizing ability is used as an oxidant, the reaction rate is relatively fast and the time required may be shorter; while using oxidants with relatively weak oxidizing ability such as hydrogen peroxide, the reaction time may need to be appropriately extended. For example, under temperature conditions of 120°C to 160°C, the second preset time is 2h to 3.5h.

[0075] In some embodiments, the oxidizing agent includes one or more of hydrogen peroxide, hydrogen peroxide, oxygen, and ozone.

[0076] The active ingredient in hydrogen peroxide is hydrogen peroxide, a relatively mild green oxidant. Its molecular structure contains peroxide bonds, giving it strong oxidizing power. Hydrogen peroxide decomposes solely into water and oxygen, without introducing any additional impurity ions, thus minimizing the impact on subsequent phosphoric acid recycling. Furthermore, the oxidation process is relatively mild, making it easy to control the reaction rate and progress.

[0077] In some embodiments, the concentration of hydrogen peroxide is ≥ 25%.

[0078] When the concentration of hydrogen peroxide is ≥25%, the number of hydrogen peroxide molecules per unit volume increases significantly, and they can react more quickly and fully with nitrogen-containing organic cations, attacking their chemical bonds, prompting the rapid degradation of nitrogen-containing organic cations, and greatly enhancing the overall oxidizing ability of the oxidation system.

[0079] During the oxidation reaction, free radicals are continuously consumed as the reaction proceeds. Low concentrations of hydrogen peroxide at high temperatures produce a limited number of free radicals, making it difficult to maintain oxidative strength in the later stages of the reaction, which can lead to incomplete oxidation. Hydrogen peroxide with a concentration of 25% or higher, on the other hand, provides a continuous and stable supply of hydroxyl radicals throughout the reaction, ensuring sufficient oxidative capacity both in the initial and later stages of the oxidation reaction. This effectively prevents premature stagnation of the reaction due to insufficient free radical supply, maintaining the efficiency and sustainability of the oxidation process.

[0080] Oxygen is widely available and low-cost, and can be introduced directly. Oxygen as an oxidant will not introduce new chemical substances. Oxygen can also be introduced in the form of liquid oxygen. Ozone has extremely strong oxidizing properties and has stronger oxidizing ability than oxygen. It oxidizes very quickly and can completely oxidize nitrogen-containing organic cations in a short period of time. It is especially suitable for treating difficult-to-degrade nitrogen-containing organic compounds. Moreover, its decomposition product is oxygen, which will not cause secondary pollution.

[0081] In the embodiment of the present application, one or more oxidants selected from hydrogen peroxide, hydrogen peroxide, oxygen and ozone can be selected for combined use.

[0082] In step S400, after the above treatment, the liquid phase component is mainly phosphoric acid. By collecting the liquid phase component, phosphoric acid that can be reused in the production process can be obtained, thereby achieving efficient recycling of phosphoric acid.

[0083] It can be understood that step S400 is executed after step S300, and there is no strict order between step S200 and step S400. Step S200 and step S400 can be executed synchronously. Step S200 can be executed before step S400 or after step S400.

[0084] In some embodiments, see Figure 3The step of collecting the liquid phase component to obtain reusable phosphoric acid comprises: S401: collecting the liquid phase components; S402: Concentrating the liquid phase component to obtain reusable phosphoric acid.

[0085] The liquid phase components after oxidation treatment may contain water and a small amount of small-molecule impurities in addition to the target product, phosphoric acid. For example, when hydrogen peroxide is used as the oxidant, water will remain in the liquid phase components. By removing this water, the phosphoric acid concentration is increased and concentrated to meet the reusable standard. Removing this water not only reduces the volume and weight of phosphoric acid during subsequent storage, transportation, and use, thus reducing costs, but more importantly, as the water evaporates, some low-boiling-point small-molecule impurities, such as small-molecule organic acids, are also removed, initially improving the purity of the phosphoric acid and laying the foundation for its reuse in chemical production.

[0086] To further improve the purity of phosphoric acid, the concentrated phosphoric acid solution can be subjected to cooling crystallization. By controlling the cooling rate and temperature, phosphoric acid is crystallized from the solution. During the crystallization process, most impurities remain in the mother liquor due to their different solubility characteristics in solution from phosphoric acid. The phosphoric acid crystals can also be recrystallized. The phosphoric acid crystals are dissolved in an appropriate amount of pure water and then cooled and crystallized again. This process can further remove impurities remaining in the crystals and improve product purity. After recrystallization, the phosphoric acid crystals are washed with a small amount of pure water or an organic solvent such as ethanol to remove impurities adsorbed on the crystal surface. The amount of washing solution used and the number of washes must be controlled during the washing process to avoid excessive dissolution and loss of the phosphoric acid crystals. In some embodiments, the method further includes: absorbing and collecting gas phase components, where the gas phase components include carbon dioxide and nitrogen dioxide.

[0087] The gaseous components produced after oxidation treatment of the raffinate phase include gases such as carbon dioxide and nitrogen dioxide. If they are directly discharged, it will not only cause waste of resources but also pollute the environment. Therefore, it is of great significance to absorb and collect them.

[0088] By absorbing and collecting gaseous components, on the one hand, harmful gas emissions can be reduced and the concept of green environmental protection can be implemented; on the other hand, the collected gas can be utilized as a resource, such as using carbon dioxide to prepare carbonated beverages, dry ice, carbonates, or as a chemical raw material to participate in organic synthesis reactions; the collected nitrogen dioxide can be further processed and converted into valuable chemicals such as nitric acid, realizing the recycling of resources and improving the economic and environmental benefits of the entire treatment process.

[0089] In some embodiments, the step of absorbing and collecting the gas phase components includes: absorbing the gas phase components through multiple stages of clean water to obtain a first absorption liquid and residual gas; and absorbing the residual gas through multiple stages of alkaline solution to obtain a second absorption liquid.

[0090] The gas phase components are absorbed through multiple stages of clean water, primarily due to the differences in solubility of carbon dioxide and nitrogen dioxide in water and some chemical reactions. Carbon dioxide is slightly soluble in water, while nitrogen dioxide is readily soluble in water and reacts chemically with water. Because the gas phase also contains the oxidant O2, nitrogen dioxide generates nitric acid in the presence of oxygen. This reaction provides the basis for the removal of nitrogen dioxide from the gas phase. During the gas absorption process, the gaseous components first enter the first-stage clean water absorption unit, which can be a spray tower or a packed tower. In the spray tower, for example, clean water is sprayed down from the top in uniform droplets, while the gaseous components flow upward from the bottom of the tower. This allows for full contact between the gas and liquid phases, achieving initial absorption of carbon dioxide and nitrogen dioxide. After the first stage of absorption, the gas enters the next stage of clean water absorption, where the process repeats. For example, three to five stages of clean water absorption units are configured, with the clean water in each stage periodically replaced or recycled based on absorption performance. As absorption progresses, the clean water gradually absorbs nitrogen dioxide from the gas, forming a first absorption liquid. When the nitric acid concentration in the first absorption liquid reaches a certain level, it can be collected and processed for subsequent nitric acid recovery or further processing. After multiple stages of clean water absorption, the majority of the nitrogen dioxide is absorbed and converted, leaving the remaining gas primarily as carbon dioxide. The remaining gas is absorbed by multiple stages of alkaline solution, which neutralizes the acidic gas to effectively absorb and remove carbon dioxide. For example, the alkaline solution is sodium hydroxide solution, and carbon dioxide reacts with sodium hydroxide. If there is an excess of carbon dioxide, it will further react to form sodium bicarbonate. During the gas absorption process, the remaining gas enters the first-stage alkali solution absorption device, which can also adopt the structure of a spray tower or a packed tower. Alkali solution is sprayed from the top of the tower, fully contacts the gas from bottom to top, and a neutralization reaction occurs. The gas after the first-stage absorption enters the subsequent multi-stage alkali solution absorption device in sequence to further improve the absorption effect. For example, 2 to 3 stages of alkali solution absorption devices are set. After multi-stage alkali solution absorption, a second absorption liquid is obtained, which mainly contains sodium carbonate, sodium bicarbonate and other substances. The second absorption liquid can be further processed, for example, by recovering the salt substances therein through evaporation and crystallization, so as to achieve resource recycling. After alkali solution absorption, the content of harmful components in the discharged gas is greatly reduced, basically meeting the environmental protection emission standards. In summary, the recycling and treatment method of the embodiment of the present application abandons the traditional neutralization method, and avoids the generation of solid waste through extraction and oxidation treatment, effectively solves the secondary pollution problem, and is more in line with environmental protection requirements. The nitrogen-containing organic cations in the extract phase are oxidized and degraded by an oxidant, which can effectively remove organic matter in waste phosphoric acid and improve the treatment effect of waste phosphoric acid. The low-temperature process with an operating temperature of ≤120°C significantly reduces energy consumption and saves a lot of energy costs compared to the high-temperature treatment process. At the same time, low-temperature conditions have low equipment requirements and do not require complex equipment, further reducing equipment investment and maintenance costs. The present application can directly process waste acid, simultaneously recover phenolic compounds and high-purity phosphoric acid, achieve efficient recycling of useful components in waste phosphoric acid, convert waste into reusable resources, reduce processing costs, and improve resource utilization. The recovery rate of phenolic compounds is more than 99%, and the phosphoric acid recovery purity can reach 94.65%, which can be directly recycled for production, with good economic and environmental benefits.

[0091] Second, see Figure 4 The embodiment of the present application provides a system for recovering and treating phenol-containing organic phosphoric acid waste liquid, comprising: an extraction device 100, for receiving phenol-containing organic phosphoric acid waste liquid and an extractant, extracting phenolic compounds in the phenol-containing organic phosphoric acid waste liquid by the extractant, and separating them into an extract phase and a raffinate phase; a separation device 200, connected to the extraction device 100, for receiving the extract phase and performing a desolventizing treatment on the extract phase; an oxidation device 300, connected to the extraction device 100, for receiving the raffinate phase and an oxidant for an oxidation reaction; and a gas absorption device 400, connected to the oxidation device 300, for receiving and absorbing and collecting gaseous phase components produced by the oxidation reaction.

[0092] In an embodiment of the present application, the extraction device 100 is used to receive phenol-containing organic phosphoric acid waste liquid and an extractant. In the extraction device 100, the phenolic compounds in the phenol-containing organic phosphoric acid waste liquid are extracted by the extractant, and then the extract phase and the raffinate phase are separated. For example, the extraction device 100 may include an extraction kettle, a stirring component, a temperature control component and a feed and discharge pipe. The extraction kettle is made of corrosion-resistant material to adapt to the strong corrosiveness of the phenol-containing organic phosphoric acid waste liquid. For example, the material of the extraction kettle is stainless steel lined with polytetrafluoroethylene. The stirring component can be equipped with an adjustable speed agitator to achieve sufficient mixing of the phenol-containing organic phosphoric acid waste liquid and the extractant through the rotation of the blades. The blade types include turbine type, paddle type, etc., which can be selected according to actual processing requirements. The temperature control component can control the extraction temperature. For example, the extraction temperature is in the range of 50°C to 100°C. The feed pipes are connected to the phenol-containing organic phosphoric acid waste liquid storage tank and the extractant storage tank respectively, and the discharge pipes lead to the separation device 200 and the oxidation device 300 respectively. Flow control valves and pressure gauges can be installed on the pipes to control the flow and pressure of the materials. Phenol-containing organophosphoric acid wastewater and an extractant are fed into an extraction kettle through a feed pipe in a predetermined mass ratio. A stirring assembly rapidly mixes the two phases, allowing the extractant to extract the phenols from the wastewater. After extraction, the mixture is allowed to stand and separate into layers. By utilizing the density difference between the two phases, the extract phase is delivered to a separation unit 200 through a discharge pipe, while the raffinate phase is transported to an oxidation unit 300. The separation device 200 is used to receive the extract phase and perform a desolventizing treatment on the extract phase. Exemplarily, the separation device 200 is a distillation tower equipped with a heating component, a condensing component, a distillation component, and a material delivery pump. The distillation tower is internally provided with multiple layers of trays or packing to increase the gas-liquid mass transfer area. The distillation system includes a reflux device and a fractionating head, which can achieve separation based on the boiling point difference between the extractant and the phenolic compounds. The material delivery pump is used to transport the extract phase to the distillation tower and transport the separated phenolic compounds and recovered extractant to corresponding storage tanks, respectively. The oxidation device 300 is used to receive the raffinate phase and the oxidant for oxidation reaction. For example, the oxidation device 300 includes an oxidation reactor, an oxidant addition system, a temperature control system and a gas exhaust pipeline. The oxidation reactor is also made of corrosion-resistant materials and can withstand high temperature environments of 120°C to 160°C. The oxidant addition system includes an oxidant storage tank, a metering pump and a delivery pipeline, which can control the amount of oxidant added. The stirring system is used to ensure that the oxidant and the raffinate phase are fully mixed to increase the reaction rate. The temperature control system maintains the reaction temperature through electric heating or steam heating, and is equipped with a cooling device to prevent the temperature from being too high. The gas exhaust pipeline is connected to the gas absorption device 400, which is used to transport the gaseous components produced by the oxidation reaction to subsequent processing links. After the raffinate phase enters the oxidation reactor, an oxidant is added through a dosing system at a set ratio. At a temperature of 120°C to 160°C, the oxidant reacts with the nitrogen-containing organic cations in the raffinate phase. After the reaction is complete, the liquid phase is discharged through a discharge pipe for further processing to produce reusable phosphoric acid. The gaseous phase flows through a gas discharge pipe and enters the gas absorption device 400. The gas absorption device 400 includes a carbon dioxide absorption device 401 and a nitrogen dioxide absorption device 402. The nitrogen dioxide absorption device 402 can be a multi-stage clean water absorption tower, the carbon dioxide absorption device 401 can be a multi-stage alkali solution absorption tower, and the gas absorption device 400 can also include a circulation pump, an absorption liquid storage tank and a gas discharge pipeline. For example, the clean water absorption tower and the alkali solution absorption tower both adopt a spray tower or a packed tower structure, and a spray device, a packing layer and a demister are provided in the tower. The circulation pump is used to realize the recycling of the absorption liquid, and the absorption liquid storage tank stores clean water and alkali solution respectively, and is equipped with a liquid level control system and a replenishing device. The gas discharge pipeline connects the oxidation device 300 and the final gas discharge port for transporting and discharging the treated gas. In some embodiments, a concentration device 500 is further included. The concentration device 500 is connected to the oxidation device 300 and is used to receive the liquid phase components after the oxidation reaction and concentrate the liquid phase components.

[0093] Concentrator 500 is connected to oxidizer 300. The liquid phase components processed by oxidizer 300 are directly transferred to concentrator 500 for concentration, ensuring the continuity of the processing flow. The concentrated phosphoric acid then enters a subsequent refining step, which may be necessary to further improve its purity and ultimately produce high-quality, reusable phosphoric acid.

[0094] In the phenol-containing organic phosphoric acid waste liquid recovery and treatment system of the embodiment of the present application, each device is closely connected and operates in coordination. The extraction device realizes the preliminary separation of phenolic compounds, which reduces the burden on subsequent treatment; the separation device efficiently recovers phenolic compounds and extractants, improving resource utilization; the oxidation device deeply treats the residual phase and degrades nitrogen-containing organic cations; the gas absorption device treats the gas phase components produced by oxidation to achieve zero pollutant emissions. The entire system can efficiently treat phenol-containing organic phosphoric acid waste liquid, simultaneously recover phenolic organic matter and high-purity phosphoric acid, avoid secondary pollution, reduce treatment costs, have significant economic and environmental benefits, and is suitable for large-scale industrial applications.

[0095] Example The following examples more particularly describe the present disclosure, and these examples are intended to be illustrative only, as various modifications and variations within the scope of the present disclosure will be apparent to those skilled in the art. Unless otherwise indicated, all parts, percentages, and ratios reported in the following examples are by weight, and all reagents used in the examples are commercially available or synthesized according to conventional methods and used directly without further processing, and all instruments used in the examples are commercially available.

[0096] Example 1 Extraction section: The phenol-containing organic phosphoric acid waste liquid is passed into the extraction device, the extractant is continuously added to the extraction device, and the extraction is stirred at 100°C for 30 minutes; the extractant is methyl isobutyl ketone, and the mass ratio of the organic phosphoric acid waste liquid to the extractant is 4:1; after standing and stratification, the extract phase and the raffinate phase are separated, and the above operation steps are repeated 3 times; the phenol-containing organic phosphoric acid waste liquid includes the following components by mass grouping: 2.2% water, 8.8% phenolic compounds, 12.2% basic nitrogen compounds, and 76.8% phosphate.

[0097] Separation stage: The extract phase is passed into the separation device, which is a distillation tower; the system pressure of the distillation tower is 20-60kPa, the tower top temperature is 60-120℃, and the reflux ratio is 10:1; Oxidation section: The raffinate phase is introduced into the oxidation device, and high-purity oxygen is introduced into the extraction device. The oxidation reaction temperature is 120-160°C and the time is 3 hours.

[0098] Absorption section: The gas generated in the oxidation section is introduced into the gas absorption device, which includes a nitrogen dioxide absorption device and a carbon dioxide absorption device. The nitrogen dioxide absorption device is composed of three water absorption towers connected in series, and the carbon dioxide absorption device is composed of three sodium hydroxide absorption towers connected in series.

[0099] Concentration section: The liquid components treated by the oxidation device are transported to the concentration device for concentration. The concentration device is a distillation tower with a system pressure of 20-60kPa, a tower top temperature of 80-130°C, and a reflux ratio of 10:1.

[0100] 100 tons of waste acid can produce more than 79 tons of concentrated acid. The recovered phosphoric acid has a purity of more than 95% and can be directly recycled for production. The recovery rate of phenolic compounds is more than 95%.

[0101] Example 2 The phenol-containing organic phosphoric acid waste liquid was treated in a process similar to that of Example 1, except that the extraction step was carried out at 60° C. with stirring for 40 minutes.

[0102] 100 tons of waste acid produces 79.35 tons of concentrated acid. The recovered phosphoric acid has a purity of 96.82% and can be directly recycled for production. The recovery rate of phenolic compounds is 96.5%.

[0103] Example 3 The phenol-containing organic phosphoric acid waste liquid was treated in a process similar to that of Example 1, except that in the extraction section, the methyl isobutyl ketone in Example 1 was replaced by tert-amyl methyl ether.

[0104] 100 tons of waste acid produces 79.16 tons of concentrated acid. The recovered phosphoric acid has a purity of 96.25% and can be directly recycled for production. The recovery rate of phenolic compounds is 97.8%.

[0105] Example 4 The phenol-containing organic phosphoric acid waste liquid was treated in a process similar to that of Example 1, except that in the oxidation section, high-purity oxygen was replaced with 30% hydrogen peroxide, and high-purity oxygen was introduced into the extraction device. The mass ratio of hydrogen peroxide to waste phosphoric acid was 2:1.

[0106] A concentration section is added after the absorption section to transport the liquid components treated by the oxidation device to the concentration device for concentration. The concentration device is a distillation tower with a system pressure of 20-60kPa, a tower top temperature of 80-130°C, and a reflux ratio of 10:1.

[0107] 100 tons of waste acid produces 79.76 tons of concentrated acid. The recovered phosphoric acid has a purity of 95.83% and can be directly recycled for production. The recovery rate of phenolic compounds is 98.2%.

[0108] Comparative Example 1 The phenol-containing organic phosphoric acid waste liquid was treated in a process similar to that of Example 1, except that the extraction step was carried out at 25° C. with stirring for 30 minutes.

[0109] 100 tons of waste acid produced 83.34 tons of concentrated acid, the phosphoric acid recovery purity was 91.65%, and the phenol compound recovery rate was 80.2%.

[0110] In Comparative Example 1, due to the low extraction temperature, the recovery rate of phenolic compounds is low, which ultimately leads to incomplete oxidation when the same amount of oxidant is added. In addition, the recovered phosphoric acid contains phenolic compounds and alkaline nitrides, which affect the purity of the treated sample after use in production. Therefore, it cannot be directly recycled for production.

[0111] Comparative Example 2 The phenol-containing organic phosphoric acid waste liquid was treated in a process similar to that of Example 1, with the difference that in the oxidation stage, the oxidation reaction temperature was 80°C.

[0112] 100 tons of waste acid produced 87.52 tons of concentrated acid, the phosphoric acid recovery purity was 85.26%, and the phenol compound recovery rate was 98.6%.

[0113] In Comparative Example 2, due to the low oxidation temperature, the oxidation level of the oxidant is reduced and complete oxidation cannot be achieved. The recovered phosphoric acid contains phenolic compounds and alkaline nitrides, which affect the purity of the treated sample after use in production. Therefore, it cannot be directly recycled for production.

[0114] In summary, the method and system for recycling and treating phenol-containing organic phosphoric acid waste liquid in the embodiment of the present application can achieve efficient resource recovery through the collaborative process of "selective separation of phenols by extractant + oxidative degradation by oxidant + purification of phosphoric acid", with a phenolic compound recovery rate of more than 95% and a phosphoric acid recovery purity of 95%, which can be directly recycled for production; at the same time, it is environmentally friendly and economical, and can avoid hazardous waste treatment costs. 100 tons of waste phosphoric acid produces more than 79 tons of concentrated acid; the organic matter degradation rate is 100%, reducing secondary pollution; at the same time, the operating temperature of 100-160°C is relatively low, and the by-products after oxidation are absorbed to produce nitric acid and carbonate products, without other pollution.

[0115] The above is only a specific implementation method of the present application. Those skilled in the art can clearly understand that for the convenience and brevity of description, the specific working processes of the systems, modules and units described above can refer to the corresponding processes in the aforementioned method embodiments, and will not be repeated here. It should be understood that the scope of protection of the present application is not limited to this. Any technician familiar with this technical field can easily think of various equivalent modifications or replacements within the technical scope disclosed in this application, and these modifications or replacements should be included in the scope of protection of this application.

Claims

1. A method for recovering and treating phenol-containing organic phosphoric acid waste liquid, characterized in that: include: Mixing the phenol-containing organic phosphoric acid waste liquid to be treated with an extractant for extraction treatment to obtain an extract phase and a raffinate phase, wherein the raffinate phase includes nitrogen-containing organic cations and phosphate; performing a deagent treatment on the extract phase to obtain a phenolic compound; The raffinate phase is oxidized by using an oxidant to degrade nitrogen-containing organic cations to obtain a gas phase component and a liquid phase component; The liquid phase components are collected to obtain reusable phosphoric acid.

2. The method for recycling phenol-containing organic phosphoric acid waste liquid according to claim 1, wherein: The step of mixing the phenol-containing organic phosphoric acid waste liquid to be treated with an extractant for extraction treatment to obtain an extract phase and a raffinate phase comprises the following sub-steps: Mixing the phenol-containing organic phosphoric acid waste liquid with an extractant at a temperature of 50° C. to obtain a mixed liquid; Stirring the mixed liquid for a first preset time, allowing it to stand and separate into the extract phase and the raffinate phase; Each sub-step of the extraction process is cyclically performed at least once.

3. The method for recovering phenolic organic phosphoric acid waste liquid according to claim 1 or 2, characterized in that: The extractant includes one or more of alkane compounds, aromatic compounds, ether compounds, ester compounds and ketone compounds; Optionally, the mass ratio of the phenol-containing organic phosphoric acid waste liquid to the extractant is (2-6):

1.

4. The method for recovering phenol-containing organic phosphoric acid waste liquid according to claim 1, wherein: The step of mixing the raffinate phase with an oxidant to oxidize to obtain a gas phase component and a liquid phase component comprises: Under the temperature condition of 120° C. to 160° C., the oxidant is introduced into the raffinate phase, and the oxidation reaction continues for a second preset time.

5. The method for recovering phenol-containing organic phosphoric acid waste liquid according to claim 4, wherein: The oxidant includes one or more of hydrogen peroxide, hydrogen peroxide, oxygen and ozone; Optionally, the concentration of hydrogen peroxide is ≥25%.

6. The method for recovering phenol-containing organic phosphoric acid waste liquid according to claim 1, wherein: The step of collecting the liquid phase components to obtain reusable phosphoric acid comprises: The liquid phase components are collected; and the liquid phase components are concentrated to obtain reusable phosphoric acid.

7. The method for recovering phenol-containing organic phosphoric acid waste liquid according to claim 1, wherein: Also includes: Absorbing and collecting the gas phase components, wherein the gas phase components include carbon dioxide and nitrogen dioxide; Optionally, the step of absorbing and collecting the gas phase components includes: absorbing the gas phase components through multiple stages of clean water to obtain a first absorption liquid and residual gas; The remaining gas is absorbed by multi-stage alkaline solution to obtain a second absorption liquid.

8. The method for recovering phenol-containing organic phosphoric acid waste liquid according to claim 1, wherein: The phenol-containing organic phosphoric acid waste liquid comprises the following components by mass fraction: 2-4% water, 8-10% phenolic compounds, 12-14% alkaline nitrogen compounds, and 74-78% phosphate radicals.

9. A system for recovering and treating phenol-containing organic phosphoric acid waste liquid, characterized in that: include: An extraction device is used to receive phenol-containing organic phosphoric acid waste liquid and an extractant, extract phenolic compounds in the phenol-containing organic phosphoric acid waste liquid with the extractant, and separate to obtain an extract phase and a raffinate phase; a separation device connected to the extraction device, configured to receive the extraction phase and perform a desolventizing treatment on the extraction phase; an oxidation device, connected to the extraction device, for receiving the raffinate phase and an oxidant for an oxidation reaction; The gas absorption device is connected to the oxidation device and is used to receive the gas phase components generated by the oxidation reaction and absorb and collect them.

10. The system for recovering and treating phenol-containing organic phosphoric acid waste liquid according to claim 9, characterized in that: The method further comprises a concentrating device, which is connected to the oxidizing device and is used to receive the liquid phase components after the oxidation reaction and concentrate the liquid phase components.

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