Waste ore-based water body phosphorus removal agent and preparation method thereof

Abstract

The present application relates to the technical field of water pollution control, and particularly relates to a waste mine-based water body phosphorus removal agent and a preparation method thereof. The phosphorus removal agent is prepared by mixing, doping with ZrO2, grafting with a PNQE ligand and loading with a ternary metal cluster, with steel slag and red mud as the base body. The PNQE ligand is synthesized by step-by-step reaction of raw materials such as ethylenediamine and chloromethylphosphonic acid diethyl ester. The phosphorus removal agent realizes efficient removal of organic phosphorus and inorganic phosphorus by synergistic adsorption of phosphorus through anthraquinone-based oxidation of organic phosphorus and phosphonic acid groups and metal clusters, and has good cycle stability, wide pH adaptability, low heavy metal dissolution, and both resource utilization and environmental protection benefits.

Description

Technical Field

[0001] The present invention relates to the technical field of water pollution control, in particular to a waste ore-based water body phosphorus removal agent and a preparation method thereof. Background Art

[0002] Eutrophication is a global environmental problem, with phosphorus pollution being a major contributing factor. Excessive phosphorus discharge from industrial wastewater, agricultural runoff, and domestic sewage can stimulate algal blooms, leading to dissolved oxygen depletion, biodiversity loss, and ecosystem collapse. Currently, phosphorus removal technologies primarily include chemical precipitation, biological treatment, and adsorption. While chemical precipitation is effective, it requires the continuous addition of reagents such as aluminum and iron salts, resulting in high operating costs and the production of large amounts of heavy metal-laden sludge. Biological treatment has low organic phosphorus conversion efficiency, is significantly affected by water quality fluctuations, and struggles to consistently meet discharge standards. Adsorption has attracted significant attention due to its ease of operation and environmental friendliness. Adsorbents derived from industrial solid wastes (such as steel slag and red mud) have the potential to be a "waste treatment" approach. Steel slag, rich in active components such as CaO and Fe₂O₃, can fix phosphates through precipitation. Red mud, with its porous structure and aluminum oxides, possesses a certain adsorption capacity. However, unmodified waste mineral materials have obvious defects: low specific surface area, few active sites, high risk of heavy metal dissolution, limited removal efficiency of low-concentration phosphorus (especially organic phosphorus), and are easily interfered by coexisting anions, making it difficult to meet the deep phosphorus removal needs of complex water bodies.

[0003] In recent years, researchers have attempted to improve the performance of waste ore by loading metal oxides or functional ligands, but most modification processes suffer from poor grafting stability and insufficient oxidation-adsorption synergy. For example, zirconium doping can enhance material stability but lacks organophosphorus degradation capabilities. Ligand modification, while capable of introducing specific sites, often results in detachment during recycling due to weak binding forces. Therefore, there is an urgent need to develop waste ore-based materials that combine efficient phosphorus removal performance, excellent cyclic stability, and environmental safety, achieving the win-win goal of both phosphorus pollution control and solid waste resource utilization. Summary of the Invention

[0004] The purpose of the present invention is to solve the shortcomings of the prior art and to propose a waste ore-based water phosphorus removal agent and a preparation method thereof.

[0005] Based on the above objectives, the present invention provides a waste mineral-based water dephosphorization agent, comprising the following raw materials in parts by weight: steel slag: 40-60 parts, red mud: 10-20 parts, zirconium oxychloride: 1-3 parts, PNQE (wherein P represents a phosphonic acid group, N represents a secondary amino group, Q represents an anthraquinone group, and E represents a hydroxyethyl group) ligand: 5-10 parts, lanthanum nitrate: 1-2 parts, cerium nitrate: 1-2 parts, and iron nitrate: 0.1-0.3 parts;

[0006] The preparation method of the PNQE ligand is as follows:

[0007] (1) Under nitrogen protection, ethylenediamine was added to anhydrous ethanol, and the temperature was raised to 70-80°C. Diethyl chloromethylphosphonate was added dropwise for 1-2 hours. After the addition was completed, the reaction was continued for 4-8 hours. After cooling to room temperature, the reaction solution was washed three times with saturated sodium carbonate solution, concentrated under reduced pressure to remove the organic solvent, and extracted three times with ethyl acetate. The organic phases were combined, dried over anhydrous sodium sulfate, and filtered. After the filtrate was concentrated, it was added to petroleum ether and stirred for 10-20 minutes. The filtrate was transferred to a separatory funnel and allowed to stand. The lower layer product was collected and dried to obtain intermediate A. The chemical reaction equation is as follows:

[0008] One of the amino groups in ethylenediamine acts as a nucleophilic center. The lone pair of electrons from the nitrogen atom attacks the saturated carbon atom connected to the chlorine atom in diethyl chloromethylphosphonate. The chlorine atom acts as a leaving group and detaches. The HCl generated by the reaction is captured by the other unreacted amino group in ethylenediamine, forming an ammonium salt intermediate. During post-treatment, the ammonium salt is neutralized by washing with saturated sodium sulfate to form a free product. The product was characterized by H NMR.

[0009] (2) Under nitrogen protection, intermediate A, 2-chloroethanol and potassium carbonate were added to anhydrous ethanol, heated to 70-80°C, reacted for 4-8 hours, cooled to room temperature, filtered, and the filtrate was concentrated under reduced pressure to remove the solvent. Deionized water was added to the obtained crude product, and the product was extracted three times with ethyl acetate. The organic phases were combined, dried over anhydrous sodium sulfate, and concentrated under reduced pressure to remove the solvent to obtain intermediate B. The chemical reaction equation is as follows:

[0010] The unreacted amino group in intermediate A is deprotonated under the action of potassium carbonate to form a more active nucleophile, which attacks the chlorine-substituted carbon in 2-chloroethanol and undergoes nucleophilic substitution. - The HCl generated by the reaction reacted with potassium carbonate to neutralize the nucleophilic reaction, and the product was characterized by H NMR.

[0011] (3) Under nitrogen protection, add intermediate B and anthraquinone-2-carbonyl chloride to benzene, cool to -10-0°C, add triethylamine dropwise for 1-2 hours, and after the addition is complete, heat to 10-20°C and react for 2-4 hours. Then add dilute hydrochloric acid, heat to 45-55°C, stir and hydrolyze for 1-3 hours, cool to room temperature, transfer to a separatory funnel, collect the aqueous phase, adjust the pH to neutral with sodium hydroxide solution, and solid precipitate. Cool to 0-5°C, let stand for 8-12 hours for crystallization, collect the solid by filtration, and then recrystallize with ethanol / water mixed solution to obtain PNQE ligand. The chemical reaction equation is as follows:

[0012] There are two key active sites in the molecule of intermediate B: one end is an alcoholic hydroxyl group, and the other end is two secondary amino groups, which are located close to the diethyl phosphonate group and far away from the diethyl phosphonate group, respectively. When anthraquinone-2-carbonyl chloride is added to the system, the reaction preferentially occurs on the secondary amino group far away from the diethyl phosphonate group, rather than the secondary amino group or hydroxyl group close to the phosphonic acid group. This is closely related to the electronic effect and spatial effect. The diethyl phosphonate group is a strong electron-withdrawing group, and its electron-withdrawing effect will be transferred to the neighboring atoms through the σ bond, resulting in a significant decrease in the electron density of the nitrogen atom in the secondary amino group close to it, and a weakening of the nucleophilicity; while the secondary amino group far away from the diethyl phosphonate group is less affected by the electron-withdrawing effect, the nitrogen atom retains a higher electron density, and is more nucleophilic, so it is easier to act as a nucleophilic center to attack the partially positively charged carbonyl carbon in anthraquinone-2-carbonyl chloride. , forming a stable amide bond, connecting the anthraquinone group to the molecular chain. As for the hydroxyl group, because its nucleophilicity is much weaker than that of the secondary amino group, the oxygen atom in the alcoholic hydroxyl group has a higher electronegativity than the nitrogen atom, and the hydroxyl hydrogen is tightly bound to the oxygen atom, it is difficult to dissociate into an alkoxy anion with strong nucleophilicity; at the same time, the reaction system uses low-polarity benzene as a solvent, which is not conducive to the ionization of the hydroxyl group. In addition, the low temperature further inhibits the activity of the hydroxyl group. Therefore, the hydroxyl group always remains inert and will not undergo esterification reaction with the acyl chloride. It is only retained as a potential site for subsequent grafting of the waste mineral skeleton; after the acylation reaction is completed, hydrochloric acid is added to the system and the temperature is raised to 50°C. At this time, the diethyl phosphonate group is hydrolyzed under acidic conditions, and the ester bond is broken to form a phosphonic acid group with strong adsorption capacity, finally forming a PNQE ligand with both oxidation function, adsorption function and connection function. The product was characterized by H NMR.

[0013] Preferably, the molar ratio of (1) ethylenediamine to diethyl chloromethylphosphonate is 1:0.9-1.1.

[0014] Preferably, the weight ratio of (1) ethylenediamine, anhydrous ethanol and petroleum ether is 1:8-12:5-7.

[0015] Preferably, the molar ratio of the intermediate A (2), 2-chloroethanol and potassium carbonate is 1:1-1.2:1.2-1.5.

[0016] Preferably, the weight ratio of the intermediate A (2), anhydrous ethanol and deionized water is 1:8-12:5-7.

[0017] Preferably, the molar ratio of the intermediate B, anthraquinone-2-carbonyl chloride and triethylamine in (3) is 1:1-1.2:1-1.2.

[0018] Preferably, the weight ratio of the intermediate B (3), benzene and dilute hydrochloric acid is 1:8-12:3-5.

[0019] Preferably, the concentration of the (3) dilute hydrochloric acid is 1 mol / L.

[0020] Preferably, the concentration of the sodium hydroxide solution in (3) is 1 mol / L.

[0021] Preferably, the ethanol / water mixed solution in (3) is prepared by mixing ethanol and water in a weight ratio of 2:3.

[0022] Further, the application also provides a preparation method of the above-mentioned waste ore-based water body phosphorus removal agent, which specifically comprises the following steps:

[0023] S1. In a reaction kettle, steel slag and red mud are added into deionized water, the reaction kettle is sealed, the temperature is raised to 280-320°C, stirring is performed for 1-3 h, the temperature is cooled to room temperature, filtration, washing, and drying are performed, and then ball milling is performed to pass a 200-mesh screen to obtain a steel slag / red mud mixture. Under supercritical water conditions, the compact structure of the steel slag and the red mud is destroyed, the lattice gap is expanded, free heavy metals (such as Pb 2+ , Cr 3 + , Cd 2+ ) in the steel slag and the red mud are dissolved in water due to the strong penetration and solvation of supercritical water, and CaO and Fe2O3 and other beneficial ingredients are recrystallized to form a porous structure, and the number of surface hydroxyl groups is increased. After filtration, the dissolved heavy metal ions can be removed with the filtrate, and washing can further reduce the residual heavy metal content. On the one hand, the specific surface area of the material can be increased and the surface active sites can be increased through physical activation; on the other hand, the dissolution of the heavy metals is promoted and the heavy metals are removed through filtration, so that secondary pollution caused by the dissolution of the heavy metals when the material is used as a phosphorus removal agent in the subsequent process is avoided, and Ca 2+ , Al 3+ and other metal ions beneficial to phosphorus removal in the steel slag and the red mud are retained.

[0024] S2. The steel slag / red mud mixture obtained in S1 and zirconium oxychloride are added into deionized water, the temperature is raised to 50-70°C, stirring is performed for 1-3 h, the temperature is cooled to room temperature, a sodium hydroxide solution is used to adjust the pH to 9-11, filtration and drying are performed, the temperature is raised to 500-600°C in a muffle furnace, and calcination is performed for 2-4 h to obtain a ZrO2-doped steel slag / red mud mixture. In the water solution, the zirconium oxychloride is dissociated into ZrO 2+ , is adsorbed on the hydroxyl sites on the surface of the slag, and is hydrolyzed to generate ZrO(OH)2 colloid after the pH is adjusted to 9-11, and is converted into ZrO2 through calcination, and forms a covalent bond with the surface of the slag through Zr-O bonds to enhance the chemical stability of the material. The Lewis acid sites of Zr 4+ can assist in adsorbing phosphate, and provide reaction sites (condensation of the hydroxyl groups on the surface of the ZrO2 and the hydroxyl groups of the ligand) for the subsequent grafting of the PNQE ligand.

[0025] S3. The ZrO2-doped steel slag / red mud mixture obtained in S2, PNQE ligand is added into benzene, heated to 70-90℃, stirred for 4-6h, cooled to room temperature, filtered, washed with ethanol, and dried to obtain the steel slag / red mud mixture grafted with PNQE ligand. The alcohol hydroxyl group of the PNQE ligand undergoes dehydration condensation reaction with the Zr-OH on the surface of ZrO2 to form Zr-O-C covalent bond. The low polarity of the benzene solvent inhibits the side reactions of other groups (such as phosphonic acid group) of the ligand, ensuring the grafting selectivity. The PNQE ligand is fixed on the material surface through covalent grafting, introducing anthraquinone group and phosphonic acid group, and endowing the material with oxidation-adsorption synergistic function.

[0026] S4. The steel slag / red mud mixture grafted with PNQE ligand obtained in S3, lanthanum nitrate, cerium nitrate and iron nitrate are added into deionized water, stirred at room temperature for 2-4h, the pH is adjusted to 5-6 with dilute hydrochloric acid, and the stirring is continued for 30-60min. After filtration, washing and drying, the waste mine-based water body phosphorus removal agent is obtained. The phosphonic acid group and amide group of the PNQE ligand coordinate with La 3+ , Ce 3+ , Fe 3+ under the condition of pH=5-6, gradually aggregate to form ternary metal clusters, and the capture ability of phosphate is strengthened through electrostatic attraction and polydentate coordination. The metal clusters act as secondary adsorption sites and form a "double adsorption system" with the phosphonic acid group of the PNQE ligand, improving the selectivity of the material to phosphate. Meanwhile, Fe 3+ can promote the regeneration of the oxidation activity of the anthraquinone group.

[0027] Preferably, the steel slag and deionized water in S1 are in a weight ratio of 1:5-9.

[0028] Preferably, the zirconium oxychloride and deionized water in S2 are in a weight ratio of 1:85-95.

[0029] Preferably, the concentration of the sodium hydroxide solution in S2 is 1 mol / L.

[0030] Preferably, the PNQE ligand and benzene in S3 are in a weight ratio of 1:27-31.

[0031] Preferably, the lanthanum nitrate and deionized water in S4 are in a weight ratio of 1:180-220, and the concentration of the dilute hydrochloric acid is 1 mol / L.

[0032] Preferably, the action mechanism of the waste mine-based water body phosphorus removal agent is as follows:

[0033] 1. The adsorption of inorganic phosphorus is realized through "multiple site synergistic effect", involving coordination, electrostatic attraction, precipitation and other mechanisms:

[0034] Coordination adsorption of PNQE ligand phosphonic group: the oxygen atom of phosphonic group contains lone pair of electrons, which combines with phosphate through hydrogen bond or coordination bond to form stable bidentate chelate, thus being fixed;

[0035] Coordination-electrostatic adsorption of ternary metal cluster: La 3+ , Ce 3+ , Fe 3+ (Metal cluster) forms polydentate coordination compound with phosphate, and the positive charge of metal ion and the negative charge of phosphate produce strong electrostatic attraction, thus being fixed;

[0036] Precipitation of metal ions in steel slag / red mud: Ca 2+ released by steel slag forms calcium phosphate precipitate, Al 3+ in red mud forms aluminum phosphate, thus being fixed;

[0037] Lewis acid adsorption of ZrO2: Zr 4+ empty orbital coordinates with the oxygen atom of phosphate to form Zr-O-P bond, thus fixing phosphate;

[0038] 2. Removal of organic phosphorus (such as methyl phosphonate, glyphosate, etc.) requires two steps of "oxidation conversion → inorganic phosphorus adsorption", which relies on the cooperation of oxidation of anthraquinone group in PNQE ligand and adsorption site. Anthraquinone group acts as an electron acceptor to break the C-P bond or P-O bond in organic phosphorus and oxidize it to inorganic phosphate, and itself is reduced to hydroquinone group. Taking methyl phosphonate as an example, the reaction equation is: Q + CH3O-PO3H2 + H2O → QH2 + CH3OH + H2PO4 - (Q represents anthraquinone group, QH2 represents reduced hydroquinone group), the generated H2PO4 - / PO4 3- is immediately captured by the multiple adsorption sites of the phosphorus removal agent, and the adsorption mechanism is consistent with that of inorganic phosphorus;

[0039] 3. After anthraquinone group (Q) oxidizes organic phosphorus, it is converted to reduced hydroquinone group (QH2), which needs to be regenerated to Q by the oxidation of Fe 3+ to maintain continuous oxidation ability, the specific process is divided into two steps:

[0040] Fe 3+ oxidizes hydroquinone group (QH2) to anthraquinone group (Q): Fe 3+ acts as an electron acceptor and is reduced to Fe 2+ after accepting the electron of QH2, the reaction equation is: QH2 + 2Fe 3+ → Q + 2Fe 2+ + 2H + ;

[0041] Fe 2+Oxidized by oxygen to regenerate Fe 3+ :The dissolved oxygen in the system converts Fe 2+ Oxidized to Fe 3+ , complete Fe 3+ Cycle, reaction equation: 4Fe 2+ +O2+4H + →4Fe 3+ +2H2O.

[0042] Beneficial effects of the present invention:

[0043] 1. This invention synthesizes PNQE ligands and utilizes the synergistic effect of the anthraquinone and phosphonic acid groups in their molecular structure to achieve integrated removal of both organic and inorganic phosphorus. The anthraquinone group, with its unique redox properties, directly cleaves the CP or PO bonds of organic phosphorus, converting it into inorganic phosphorus. The phosphonic acid group, through coordination, efficiently captures the generated inorganic phosphorus as well as existing inorganic phosphorus in the water. Simultaneously, the ternary metal cluster forms a stable chelate with the ligand, enhancing the selective adsorption of phosphate. Combined with the precipitation of metal ions from steel slag / red mud, this creates a multi-step "oxidation-adsorption-precipitation" mechanism, significantly enhancing the removal efficiency of different forms of phosphorus.

[0044] 2. The present invention forms a covalent bond between ZrO2 and steel slag / red mud to provide a stable anchoring point for the PNQE ligand. The alcoholic hydroxyl group of the ligand condenses with the hydroxyl group on the surface of ZrO2 to form a strong Zr-OC bond, which effectively prevents the ligand from falling off during recycling. In addition, the coordination bond between the phosphonic acid group and the phosphate group is easily oxidized by OH groups during alkaline desorption. - The ternary metal clusters are resistant to acid and alkali hydrolysis and can maintain their activity for a long time. This structural design allows the material to maintain high activity after multiple "adsorption-desorption" cycles, significantly extending its service life and reducing actual application costs.

[0045] 3. The steel slag and red mud treated by the present invention destroy their dense lattice during the preparation process, which promotes the full dissolution and removal of free heavy metals while retaining Ca 2+ 、Al 3+ Beneficial metal ions such as iodine and thiocyanate can be removed to ensure that the amount of heavy metal dissolution during the use of the material is extremely low. The preparation process uses industrial waste slag as the main raw material to realize the resource utilization of waste and reduce dependence on natural mineral resources. In addition, the entire phosphorus removal process does not require the addition of toxic chemical reagents to avoid secondary pollution, thus achieving both environmental and resource benefits.

[0046] 4. The phosphonic acid group of the PNQE ligand in the present invention can be adjusted through the dissociation state at different pH levels to meet the phosphorus adsorption requirements in a wide pH range; the ternary metal cluster remains stable through the multidentate coordination of the ligand and is not easily hydrolyzed and agglomerated due to pH fluctuations; in addition, the specific coordination of the phosphonic acid group with the phosphate group and the highly matched spatial structure of the metal ion and the phosphate group significantly enhance the material's anti-interference ability against competitive anions, making it adaptable to complex water environments without the need for additional adjustment of the water pH, thereby simplifying the treatment process. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1 This is the H NMR spectrum of intermediate A prepared in Preparation Example 2 of the present invention;

[0048] Figure 2 This is the H NMR spectrum of intermediate B prepared in Preparation Example 2 of the present invention;

[0049] Figure 3 This is the H NMR spectrum of the PNQE ligand prepared in Preparation Example 2 of the present invention. DETAILED DESCRIPTION

[0050] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to specific embodiments.

[0051] The main sources of raw materials used in the present invention are as follows:

[0052] Zirconium oxychloride was purchased from Shandong Xiya Chemical Co., Ltd. with a purity of AR; lanthanum nitrate was purchased from Shanghai Maclean Biochemical Technology Co., Ltd. with a purity of 99%; cerium nitrate was purchased from Shanghai Maclean Biochemical Technology Co., Ltd. with a purity of 99%; ferric nitrate was purchased from Shanghai Maclean Biochemical Technology Co., Ltd. with a purity of 99%; ethylenediamine was purchased from Maoming Chuizi New Materials Technology Co., Ltd. with a purity of 99.6%; diethyl chloromethylphosphonate was purchased from Hefei Shenghang Pharmaceutical Technology Co., Ltd. with a purity of 98%; 2-chloroethanol was purchased from Anage Chemical & 3A (Anhui Zesheng Technology Co., Ltd.) with a purity of 98%; anthraquinone-2-carbonyl chloride was purchased from Shanghai Bide Pharmaceutical Technology Co., Ltd. with a purity of 98%.

[0053] Preparation Example 1: The preparation method of PNQE ligand is as follows:

[0054] (1) Under nitrogen protection, 10 g of ethylenediamine was added to 80 g of anhydrous ethanol, and the temperature was raised to 70 ° C. 27.94 g of diethyl chloromethylphosphonate was added dropwise for 1 h. After the addition was completed, the reaction was continued for 4 h. After cooling to room temperature, the reaction solution was washed three times with saturated sodium carbonate solution, concentrated under reduced pressure to remove the organic solvent, and extracted three times with ethyl acetate. The organic phases were combined, dried over anhydrous sodium sulfate, and filtered. After the filtrate was concentrated, it was added to 50 g of petroleum ether and stirred for 10 min. The mixture was transferred to a separatory funnel and allowed to stand. The lower layer of product was collected and dried to obtain intermediate A.

[0055] (2) Under nitrogen protection, 20 g of intermediate A, 8.84 g of 2-chloroethanol and 18.21 g of potassium carbonate were added to 160 g of anhydrous ethanol, heated to 70 ° C, reacted for 4 h, cooled to room temperature, filtered, and the filtrate was concentrated under reduced pressure to remove the solvent. 100 g of deionized water was added to the obtained crude product, and the mixture was extracted three times with ethyl acetate. The organic phases were combined, dried over anhydrous sodium sulfate, and concentrated under reduced pressure to remove the solvent to obtain intermediate B;

[0056] (3) Under nitrogen protection, 20 g of intermediate B and 23.93 g of anthraquinone-2-carbonyl chloride were added to 160 g of benzene, cooled to -10 °C, and 8.95 g of triethylamine was added dropwise for 1 h. After the addition was completed, the temperature was raised to 10 °C and the reaction was carried out for 2 h. Then 60 g of 1 mol / L dilute hydrochloric acid was added, the temperature was raised to 45 °C, and the mixture was stirred for hydrolysis for 1 h. After cooling to room temperature, the mixture was transferred to a separatory funnel and the aqueous phase was collected. The pH was adjusted to neutral with a 1 mol / L sodium hydroxide solution. Solid precipitated and the mixture was cooled to 0 °C. The mixture was allowed to stand for 8 h for crystallization. The solid was collected by filtration and then recrystallized with an ethanol / water mixed solution (ethanol and water were mixed in a weight ratio of 2:3) to obtain the PNQE ligand.

[0057] Preparation Example 2: The preparation method of PNQE ligand is as follows:

[0058] (1) Under nitrogen protection, 10 g of ethylenediamine was added to 100 g of anhydrous ethanol, and the temperature was raised to 75 ° C. 31.04 g of diethyl chloromethylphosphonate was added dropwise for 1.5 h. After the addition was completed, the reaction was continued for 6 h. After cooling to room temperature, the reaction solution was washed three times with saturated sodium carbonate solution, concentrated under reduced pressure to remove the organic solvent, and extracted three times with ethyl acetate. The organic phases were combined, dried over anhydrous sodium sulfate, and filtered. After the filtrate was concentrated, it was added to 60 g of petroleum ether and stirred for 15 min. The filtrate was transferred to a separatory funnel and allowed to stand. The lower layer of product was collected and dried to obtain intermediate A. The intermediate A was sent for H NMR to confirm the structure. The obtained spectrum is shown in the attached figure. Figure 1 As shown, the peak at the chemical shift position of 2.5ppm is deuterated DMSO, and the active hydrogen in the product does not appear in the spectrum, which is a normal phenomenon.

[0059] (2) Under nitrogen protection, 20 g of intermediate A, 9.72 g of 2-chloroethanol and 20.49 g of potassium carbonate were added to 200 g of anhydrous ethanol, heated to 75 ° C, reacted for 6 h, cooled to room temperature, filtered, and the filtrate was concentrated under reduced pressure to remove the solvent. 120 g of deionized water was added to the obtained crude product, and the product was extracted three times with ethyl acetate. The organic phases were combined, dried over anhydrous sodium sulfate, and concentrated under reduced pressure to remove the solvent to obtain intermediate B. The structure of intermediate B was confirmed by H NMR. The obtained spectrum is shown in the attached figure. Figure 2 As shown, the peak at the chemical shift position of 2.5 ppm is deuterated DMSO, and the active hydrogen in the product does not peak, which is a normal phenomenon;

[0060] (3) Under nitrogen protection, 20 g of intermediate B and 26.32 g of anthraquinone-2-carbonyl chloride were added to 200 g of benzene, cooled to -5 °C, and 9.84 g of triethylamine was added dropwise for 1.5 h. After the addition was completed, the temperature was raised to 15 °C and the reaction was carried out for 3 h. Then 80 g of 1 mol / L dilute hydrochloric acid was added, the temperature was raised to 50 °C, and the mixture was stirred for hydrolysis for 2 h. After cooling to room temperature, the mixture was transferred to a separatory funnel and the aqueous phase was collected. The pH was adjusted to neutral with a 1 mol / L sodium hydroxide solution. Solids precipitated and the temperature was lowered to 3 °C. The mixture was allowed to stand for 10 h for crystallization. The solids were collected by filtration and then recrystallized with an ethanol / water mixed solution (ethanol and water were mixed in a weight ratio of 2:3) to obtain the PNQE ligand. The PNQE ligand was sent for H NMR to confirm the structure. The obtained spectrum is shown in the attached figure. Figure 3 As shown, the peak at the chemical shift position of 2.5 ppm is deuterated DMSO, and the active hydrogen in the product does not appear, which is a normal phenomenon.

[0061] Preparation Example 3: The preparation method of PNQE ligand is as follows:

[0062] (1) Under nitrogen protection, 10 g of ethylenediamine was added to 120 g of anhydrous ethanol, and the temperature was raised to 80 ° C. 34.15 g of diethyl chloromethylphosphonate was added dropwise for 2 h. After the addition was completed, the reaction was continued for 8 h. After cooling to room temperature, the reaction solution was washed three times with saturated sodium carbonate solution, concentrated under reduced pressure to remove the organic solvent, and extracted three times with ethyl acetate. The organic phases were combined, dried over anhydrous sodium sulfate, and filtered. After the filtrate was concentrated, it was added to 70 g of petroleum ether and stirred for 20 min. The mixture was transferred to a separatory funnel and allowed to stand. The lower layer of product was collected and dried to obtain intermediate A.

[0063] (2) Under nitrogen protection, 20 g of intermediate A, 10.61 g of 2-chloroethanol and 22.77 g of potassium carbonate were added to 240 g of anhydrous ethanol, heated to 80 ° C, reacted for 8 h, cooled to room temperature, filtered, and the filtrate was concentrated under reduced pressure to remove the solvent. 140 g of deionized water was added to the obtained crude product, and the mixture was extracted three times with ethyl acetate. The organic phases were combined, dried over anhydrous sodium sulfate, and concentrated under reduced pressure to remove the solvent to obtain intermediate B;

[0064] (3) Under nitrogen protection, 20 g of intermediate B and 28.72 g of anthraquinone-2-carbonyl chloride were added to benzene, cooled to 0 ° C, and 10.74 g of triethylamine was added dropwise for 2 h. After the addition was completed, the temperature was raised to 20 ° C and the reaction was carried out for 4 h. Then 100 g of 1 mol / L dilute hydrochloric acid was added, the temperature was raised to 55 ° C, and the mixture was stirred for hydrolysis for 3 h. After cooling to room temperature, the mixture was transferred to a separatory funnel and the aqueous phase was collected. The pH was adjusted to neutral with a 1 mol / L sodium hydroxide solution. Solid precipitated, cooled to 5 ° C, and allowed to stand for 12 h for crystallization. The solid was collected by filtration and then recrystallized with an ethanol / water mixed solution (ethanol and water were mixed in a weight ratio of 2:3) to obtain the PNQE ligand.

[0065] Comparative Preparation Example 1: The difference between Comparative Preparation Example 1 and Preparation Example 2 is that step (3) is omitted and intermediate B is the PNQE ligand.

[0066] Comparative Preparation Example 2: The difference between Comparative Preparation Example 2 and Preparation Example 2 is that dilute hydrochloric acid with a concentration of 1 mol / L is not added in step (3). The specific preparation method is as follows:

[0067] The preparation method of PNQE ligand is as follows:

[0068] (1) Same as Preparation Example 2 (1);

[0069] (2) Same as Preparation Example 2 (2);

[0070] (3) Under nitrogen protection, 20 g of intermediate B and 26.32 g of anthraquinone-2-carbonyl chloride were added to 200 g of benzene, cooled to -5 °C, and 9.84 g of triethylamine was added dropwise for 1.5 h. After the addition was completed, the temperature was raised to 15 °C, and the reaction was continued for 3 h. The solvent was removed by concentration under reduced pressure. 100 g of ethyl acetate was added to the residue, and the mixture was washed once with deionized water and once with saturated brine. The organic phase was collected, dried over anhydrous sodium sulfate, filtered, and concentrated under reduced pressure to remove the solvent. The PNQE ligand was then recrystallized from an ethanol / water mixed solution (ethanol and water were mixed in a weight ratio of 2:3) to obtain the PNQE ligand.

[0071] Comparative Preparation Example 3: The difference between Comparative Preparation Example 3 and Preparation Example 2 is that step (2) is omitted, and the intermediate A is directly reacted with anthraquinone-2-carbonyl chloride to obtain the PNQE ligand.

[0072] Example 1: A specific preparation method of a waste ore-based water phosphorus removal agent, comprising the following steps:

[0073] S1. In a reactor, 40 g of steel slag and 10 g of red mud were added to 200 g of deionized water. The reactor was sealed and heated to 280°C. Stirring was performed for 1 h, cooled to room temperature, filtered, washed, dried, and ball-milled through a 200-mesh sieve to obtain a steel slag / red mud mixture.

[0074] S2. The steel slag / red mud mixture obtained in S1 and 1 g of zirconium oxychloride were added to 85 g of deionized water, heated to 50°C, stirred for 1 h, cooled to room temperature, adjusted to pH 9 with 1 mol / L sodium hydroxide solution, filtered and dried, and heated to 500°C in a muffle furnace and calcined for 2 h to obtain a ZrO2-doped steel slag / red mud mixture;

[0075] S3. The ZrO2-doped steel slag / red mud mixture obtained in S2 and 5 g of the PNQE ligand prepared in Preparation Example 1 were added to 135 g of benzene, heated to 70 ° C, stirred for 4 h, cooled to room temperature, filtered, washed with ethanol, and dried to obtain a steel slag / red mud mixture grafted with PNQE ligands;

[0076] S4. The steel slag / red mud mixture grafted with PNQE ligands obtained in S3, 1 g of lanthanum nitrate, 1 g of cerium nitrate and 0.1 g of ferric nitrate were added to 180 g of deionized water, stirred at room temperature for 2 h, and the pH was adjusted to 5 with 1 mol / L dilute hydrochloric acid. The stirring was continued for 30 min, and the mixture was filtered, washed and dried to obtain a waste mineral-based water dephosphorus agent.

[0077] Example 2: A specific preparation method of a waste ore-based water phosphorus removal agent, comprising the following steps:

[0078] S1. In a reactor, 50 g of steel slag and 15 g of red mud were added to 350 g of deionized water. The reactor was sealed and heated to 300°C. Stirring was performed for 2 h, the mixture was cooled to room temperature, filtered, washed, dried, and ball-milled through a 200-mesh sieve to obtain a steel slag / red mud mixture.

[0079] S2. The steel slag / red mud mixture obtained in S1 and 2 g of zirconium oxychloride were added to 180 g of deionized water, heated to 60°C, stirred for 2 h, cooled to room temperature, adjusted to pH 10 with 1 mol / L sodium hydroxide solution, filtered and dried, and heated to 550°C in a muffle furnace and calcined for 3 h to obtain a ZrO2-doped steel slag / red mud mixture;

[0080] S3. 60 g of the ZrO2-doped steel slag / red mud mixture obtained in S2 and 7 g of the PNQE ligand prepared in Preparation Example 2 were added to 203 g of benzene, heated to 80 ° C, stirred for 5 h, cooled to room temperature, filtered, washed with ethanol, and dried to obtain a steel slag / red mud mixture grafted with a PNQE ligand;

[0081] S4. Add 60 g of the steel slag / red mud mixture grafted with PNQE ligands obtained in S3, 1.5 g of lanthanum nitrate, 1.5 g of cerium nitrate and 0.2 g of ferric nitrate to 300 g of deionized water, stir at room temperature for 3 h, adjust the pH to 5.5 with 1 mol / L dilute hydrochloric acid, continue stirring for 45 min, filter, wash and dry to obtain a waste mineral-based water dephosphorus agent.

[0082] Example 3: A specific preparation method of a waste ore-based water phosphorus removal agent, comprising the following steps:

[0083] S1. In a reactor, 60 g of steel slag and 20 g of red mud were added to 540 g of deionized water. The reactor was sealed and heated to 320°C. Stirring was performed for 3 h, cooled to room temperature, filtered, washed, dried, and ball-milled through a 200-mesh sieve to obtain a steel slag / red mud mixture.

[0084] S2. The steel slag / red mud mixture obtained in S1 and 3 g of zirconium oxychloride were added to 285 g of deionized water, heated to 70°C, stirred for 3 h, cooled to room temperature, adjusted to pH 11 with 1 mol / L sodium hydroxide solution, filtered and dried, and heated to 600°C in a muffle furnace and calcined for 4 h to obtain a ZrO2-doped steel slag / red mud mixture;

[0085] S3. The ZrO2-doped steel slag / red mud mixture obtained in S2 and 10 g of the PNQE ligand prepared in Preparation Example 3 were added to 310 g of benzene, heated to 90 ° C, stirred for 6 h, cooled to room temperature, filtered, washed with ethanol, and dried to obtain a steel slag / red mud mixture grafted with PNQE ligands;

[0086] S4. The steel slag / red mud mixture grafted with PNQE ligands obtained in S3, 2 g of lanthanum nitrate, 2 g of cerium nitrate and 0.3 g of ferric nitrate were added to 440 g of deionized water, stirred at room temperature for 4 h, and the pH was adjusted to 6 with 1 mol / L dilute hydrochloric acid. The stirring was continued for 60 min, and the mixture was filtered, washed and dried to obtain a waste mineral-based water dephosphorus agent.

[0087] Comparative Example 1: The difference between Comparative Example 1 and Example 2 is that the PNQE ligand prepared in Preparation Example 2 is replaced by the PNQE ligand prepared in Comparative Preparation Example 1.

[0088] Comparative Example 2: The difference between Comparative Example 2 and Example 2 is that the PNQE ligand prepared in Preparation Example 2 is replaced by the PNQE ligand prepared in Comparative Preparation Example 2.

[0089] Comparative Example 3: The difference between Comparative Example 3 and Example 2 is that the PNQE ligand prepared in Preparation Example 2 is replaced by the PNQE ligand prepared in Comparative Preparation Example 3.

[0090] Comparative Example 4: The difference between Comparative Example 4 and Example 2 is that: step (1) is changed to "50g of steel slag and 15g of red mud are added to 350g of deionized water, stirred at room temperature for 2h, filtered, washed, dried, ball-milled and then passed through a 200-mesh sieve to obtain a steel slag / red mud mixture", and the remaining steps are the same as Example 2.

[0091] Comparative Example 5: The difference between Comparative Example 5 and Example 2 is that step S2 is omitted, and the remaining steps are the same as Example 2.

[0092] Comparative Example 6: The difference between Comparative Example 6 and Example 2 is that step S3 is omitted, PNQE ligand is not added to the waste ore-based water phosphorus removal agent, and the remaining steps are the same as Example 2.

[0093] Comparative Example 7: The difference between Comparative Example 7 and Example 2 is that step S4 is omitted, and the remaining steps are the same as Example 2.

[0094] Performance testing:

[0095] 1. Inorganic phosphorus removal rate: Prepare a KH2PO4 solution with an initial concentration of 50 mg / L (simulating inorganic phosphorus wastewater), adjust the pH to 2.0, 4.0, 5.0, 5.5, 6.0, 7.0, 8.0, and 10.0, take 500 mL of each of the above solutions, add the phosphorus removal agents prepared in Examples 1-3 and Comparative Examples 1-7, respectively, at a dosage of 1 g / L, place in a 25°C constant temperature water bath oscillator, and stir at 150 r / min for 2 h. After the end, filter with a 0.45 μm filter membrane, take the supernatant and use ammonium molybdate spectrophotometry (GB11893-89) to determine the residual phosphorus concentration, and calculate the removal rate = , the experimental results are shown in Table 1.

[0096] 2. Organic phosphorus removal rate: A methylphosphonate solution with an initial concentration of 50 mg / L (simulating organic phosphorus wastewater) was prepared and the pH was adjusted to 2.0, 4.0, 5.0, 5.5, 6.0, 7.0, 8.0, and 10.0. 500 mL of each of the above solutions was added with the phosphorus removal agents prepared in Examples 1-3 and Comparative Examples 1-7, respectively, at a dosage of 1 g / L. The solution was placed in a 25°C constant temperature water bath oscillator and stirred at 150 rpm for 2 h. After the mixture was filtered through a 0.45 μm filter membrane, the supernatant was taken and the residual organic phosphorus concentration was determined by high performance liquid chromatography, and the generated inorganic phosphorus concentration was determined by ammonium molybdate spectrophotometry (GB11893-89). The removal rate was calculated as follows: , the experimental results are shown in Table 2.

[0097] 3. Cyclic stability: 5 g of each of the phosphorus removal agents prepared in Examples 1-3 and Comparative Examples 1-7 were added to 5 L of a KH2PO4 solution (pH 5.5) with an initial concentration of 50 mg / L, stirred at 25°C for 2 h, and filtered after the initial adsorption to determine the phosphorus removal rate.

[0098] After completing a single adsorption experiment, the reacted dephosphorus removal agent suspension was vacuum filtered with a 0.45 μm filter membrane, the filter cake was collected, and it was quickly rinsed twice with deionized water (50 mL each time) to remove impurities physically adsorbed on the surface to avoid interfering with subsequent desorption efficiency; the collected adsorption saturated dephosphorus removal agent was transferred to a 500 mL conical flask, 200 mL of 0.1 mol / L NaOH solution was added, and it was placed in a constant temperature water bath oscillator at 25°C and oscillated at 180 r / min for 30 minutes.

[0099] Desorption mechanism: Under alkaline conditions, OH - Competitive adsorption occurs with the phosphate group adsorbed on the surface of the phosphorus removal agent, destroying the coordination bond between the phosphonic acid group of the PNQE ligand and the phosphate group, while promoting the ternary metal cluster (La 3+ 、Ce 3+ 、Fe 3+ ) dissociates from the chelate with phosphate, releasing phosphate from the adsorption site into the solution;

[0100] After desorption, vacuum filtration is performed again, the filter cake is collected, and it is repeatedly washed with deionized water until the pH of the filtrate reaches neutrality, completely removing the residual NaOH and the desorbed phosphate, and avoiding the inhibition of the next adsorption by the alkaline environment; the washed dephosphorus remover is placed in an 80°C forced air drying oven for 2 hours to remove moisture, and can be used for the next adsorption cycle after cooling to room temperature;

[0101] Repeat the "adsorption-desorption-drying" process for a total of 5 cycles. Measure the phosphorus removal rate after each cycle and calculate the removal rate retention rate of the 5th cycle = , the experimental results are shown in Table 3.

[0102] 4. Anti-interference performance: A 50 mg / L KH2PO4 solution was prepared, 100 mg / L Na2SO4 (simulating sulfate interference) was added, and the pH was adjusted to 5.5. 500 mL of the above solution was added to the phosphorus removal agents prepared in Examples 1-3 and Comparative Examples 1-7 (dosage amount 1 g / L). The solution was stirred at 25°C and 150 r / min for 2 h. After filtration, the residual phosphorus concentration was measured and the phosphorus removal rate was calculated. The experimental results are shown in Table 3.

[0103] 5. Heavy Metal Dissolution Test: According to HJ 557-2010 standard, 10 g of the phosphorus removal agents prepared in Examples 1-3 and Comparative Examples 1-7 were added to 1 L of deionized water. The mixture was shaken at room temperature for 24 h. After filtration, the total heavy metal concentration in the filtrate was measured. The experimental results are shown in Table 3.

[0104] Table 1 Inorganic phosphorus removal rate at different pH values

[0105]

[0106] Table 2 Organic phosphorus removal rate at different pH values

[0107]

[0108] Table 3 Cyclic stability, anti-interference, and heavy metal dissolution tests

[0109]

[0110] Performance Analysis:

[0111] As can be seen from the experimental data in Tables 1-3, Examples 1-3, as complete formula products of the present invention, exhibit excellent comprehensive performance in terms of inorganic phosphorus and organic phosphorus removal rates, cycle stability, anti-interference performance, and heavy metal safety under different pH environments. Among them, Example 2 performs the best, with the widest pH adaptability. Within the pH range of 4.0-8.0, the removal efficiency of both remains high. The activity retention capacity during the cycle, the resistance to interfering ions in complex water bodies, and the control level of heavy metal dissolution are all in the optimal state. This is due to its precise chemical structure design and the synergistic effect of various functional units, which achieves efficient and stable oxidation-adsorption performance at the microscopic level.

[0112] The stability of the efficient adsorption of inorganic phosphorus in Example 2 over a wide pH range is due to the synergistic adaptation of multiple adsorption sites to pH. From the microscopic perspective, the phosphonic acid group of the PNQE ligand partially dissociates at pH = 4.0-6.0, generating negatively charged -PO(OH)O - , has the strongest electrostatic attraction and coordination ability with phosphate, forming a stable bidentate chelate; the ternary metal cluster (La 3+ 、Ce 3+ 、Fe 3+ ) is anchored by the phosphonic acid and amide groups of the ligands and is not easily hydrolyzed in this pH range (the concentration of free metal ions is extremely low). Its positive charge and the negative charge of the phosphate group produce a strong electrostatic interaction, while the multi-dentate coordination enhances the capture ability. In a weakly alkaline environment of pH = 6.0-8.0, the Ca released by the steel slag after supercritical activation 2+ It is easier to form calcium phosphate precipitates with phosphate groups, compensating for the effect of the decreased dissociation degree of the phosphonic acid group; the Lewis acid sites of ZrO2 coordinate with the oxygen atoms of the phosphate group to form Zr-OP bonds, which are less affected by pH fluctuations and continue to exert adsorption effects; in contrast, the control ratio is difficult to adapt to pH changes due to functional defects: the control ratio lacking phosphonic acid groups relies only on weak adsorption of metal ions, and cannot compensate for the decreased adsorption performance through different characteristics between components when the pH fluctuates, resulting in decreased adsorption efficiency; in the control ratio without ligand stabilization, the metal clusters are easy to agglomerate, and cannot maintain effective adsorption sites under acidic or alkaline conditions, and the performance decays significantly.

[0113] The stability of Example 2 for efficient removal of organic phosphorus in a wide pH range is based on the precise adaptation of the two-step synergistic "anthraquinone oxidation-inorganic phosphorus adsorption" to pH. At the microscopic level, the anthraquinone group in the PNQE ligand has the highest redox potential matching that of organic phosphorus at pH = 4.0-7.0, and has a strong driving force for electron transfer, which can efficiently break the CP bond to generate inorganic phosphorus; the Fe in the ternary metal cluster 3+ In this pH range, the ligand is used to maintain stability and avoid hydrolysis. It can quickly oxidize the reduced hydroquinone group (QH2) to anthraquinone group (Q) and convert itself into Fe 2+ Then it is reoxidized to Fe by dissolved oxygen 3+ , forming a continuous oxidation regeneration cycle, the generated inorganic phosphorus is then captured by multiple sites of phosphonic acid groups, metal clusters, steel slag / red mud and ZrO2 to avoid secondary release; in an acidic environment with pH < 4.0, although the oxidation activity of the anthraquinone group is slightly reduced, the degree of protonation of the ligand phosphonic acid group is low (still retains some negative charge), and the adsorption capacity for the generated inorganic phosphorus is stable; in a weakly alkaline environment with pH = 7.0-8.0, the nucleophilic addition side reaction of the anthraquinone group is inhibited, and Fe 3+ / Fe 2+ The cycle can still be carried out, and the Ca released by the slag 2+ The precipitation effect on inorganic phosphorus is enhanced, which makes up for the decreased efficiency of some adsorption sites; the comparative example is difficult to adapt to pH changes due to the lack of key steps: the comparative example without anthraquinone group cannot oxidize organic phosphorus and has extremely low efficiency at any pH; the lack of Fe 3+ In the comparative example, the anthraquinone group cannot be regenerated after oxidation, and the oxidation ability drops sharply due to the accumulation of hydroquinone groups when the pH is slightly higher; in the comparative example where the ligand grafting is unstable, the anthraquinone group is lost in large quantities with pH fluctuations, the oxidation-adsorption synergistic effect is broken, and the performance decays significantly.

[0114] The excellent performance of the cyclic stability of Example 2 is due to the synergistic design of its unique covalent grafting structure and renewable active sites. From the chemical structure point of view, ZrO2 forms a covalent connection with the steel slag / red mud skeleton through the Zr-O bond, providing a stable anchoring basis for the PNQE ligand. The alcoholic hydroxyl group of the PNQE ligand undergoes dehydration condensation with the Zr-OH on the surface of ZrO2 to form a strong Zr-OC covalent bond. This strong chemical bond effectively avoids the physical shedding of the ligand during repeated adsorption-desorption processes; at the same time, the phosphonic acid group of the PNQE ligand is combined with the phosphate group through a coordination bond. In the alkaline desorption stage, OH -This coordination effect can be competitively destroyed to expose the phosphonic acid group again, thereby achieving efficient regeneration of the adsorption site; the ternary metal cluster and the phosphonic acid group and amide group of the ligand form a stable chelate through multidentate coordination, which is not easily hydrolyzed and agglomerated due to pH fluctuations during the circulation process, and continuously maintains the ability to capture phosphate groups; in contrast, the control ratio has a rapid loss of active sites during the circulation due to weak ligand grafting or ligand functional defects, and the stability is significantly reduced.

[0115] The anti-interference ability of Example 2 against competitive anions is rooted in its highly selective coordination mechanism of the "double adsorption system". The phosphonic acid group of the PNQE ligand contains multiple lone pairs of electrons on oxygen atoms and can form a stable bidentate chelate with phosphate. This coordination is highly specific. The bond energy between the phosphonic acid group and the phosphate group is much higher than the binding force with other anions, and is minimally affected by interference. The La in the ternary metal cluster 3+ 、Ce 3+ It has a high charge of +3, which produces a strong electrostatic attraction with the negative charge of the phosphate group. Its ionic radius is highly matched with the spatial structure of the phosphate group. The multidentate coordination compound formed is extremely stable, further excluding the competition of other anions. In addition, the Lewis acidic site of ZrO2 coordinates with the oxygen atom of the phosphate group through an empty orbital to form a Zr-OP bond. This covalent interaction is also highly selective. The control group lacks such highly selective sites or the sites are occupied by functionally incomplete ligands, and its resistance to interfering ions is obviously insufficient.

[0116] The control of heavy metal dissolution in Example 2 is excellent, and the core lies in the regulation of the material microstructure by water activation. Under the conditions of 280-320 ° C, the dense lattice of steel slag and red mud is destroyed, the lattice gap is expanded, and the free heavy metals are fully dissolved by the strong penetration and solvation of water at this temperature, and are completely removed by filtration and washing; at the same time, beneficial components such as CaO and Fe2O3 are recrystallized to form a porous structure, and the number of surface hydroxyl groups increases, which not only retains the active metal ions required for phosphorus removal, but also avoids the secondary release of heavy metals. This optimization of the microstructure makes the heavy metal dissolution of the material strictly controlled during use. In the comparative example that has not been activated, the heavy metals are not fully dissolved, and free heavy metals still remain in the microstructure, resulting in a significantly high dissolution amount, which cannot meet environmental safety requirements.

[0117] The above description is only a preferred specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any technician familiar with the technical field, within the technical scope disclosed by the present invention, who makes equivalent replacements or changes based on the technical solution and inventive concept of the present invention, should be covered by the scope of protection of the present invention.

Claims

1. A waste ore-based water dephosphorization agent, characterized in that: The method comprises the following raw materials in parts by weight: steel slag: 40-60 parts, red mud: 10-20 parts, zirconium oxychloride: 1-3 parts, PNQE ligand: 5-10 parts, lanthanum nitrate: 1-2 parts, cerium nitrate: 1-2 parts, and iron nitrate: 0.1-0.3 parts; The preparation method of the PNQE ligand is as follows, wherein P represents a phosphonic acid group, N represents a secondary amino group, Q represents an anthraquinone group, and E represents a hydroxyethyl group: (1) Under nitrogen protection, ethylenediamine was added to anhydrous ethanol, and the temperature was raised to 70-80°C. Diethyl chloromethylphosphonate was added dropwise for 1-2 hours. After the addition was completed, the reaction was continued for 4-8 hours. After cooling to room temperature, the reaction solution was washed three times with saturated sodium carbonate solution, concentrated under reduced pressure to remove the organic solvent, and extracted three times with ethyl acetate. The organic phases were combined, dried over anhydrous sodium sulfate, and filtered. After the filtrate was concentrated, it was added to petroleum ether and stirred for 10-20 minutes. The mixture was transferred to a separatory funnel and allowed to stand. The lower layer of product was collected and dried to obtain intermediate A. (2) Under nitrogen protection, intermediate A, 2-chloroethanol and potassium carbonate were added to anhydrous ethanol, heated to 70-80°C, reacted for 4-8 hours, cooled to room temperature, filtered, and the filtrate was concentrated under reduced pressure to remove the solvent. Deionized water was added to the obtained crude product, and the product was extracted three times with ethyl acetate. The organic phases were combined, dried over anhydrous sodium sulfate, and concentrated under reduced pressure to remove the solvent to obtain intermediate B. (3) Under nitrogen protection, add intermediate B and anthraquinone-2-carbonyl chloride to benzene, cool to -10-0°C, add triethylamine dropwise for 1-2 hours, and after the addition is complete, heat to 10-20°C and react for 2-4 hours. Then add dilute hydrochloric acid, heat to 45-55°C, stir and hydrolyze for 1-3 hours, cool to room temperature, transfer to a separatory funnel, collect the aqueous phase, adjust the pH to neutral with sodium hydroxide solution, and if solid precipitates, cool to 0-5°C and let stand for 8-12 hours for crystallization. Filter and collect the solid, and then recrystallize from an ethanol / water mixed solution to obtain the PNQE ligand.

2. The waste ore-based water phosphorus removal agent according to claim 1, characterized in that: The (1) ethylenediamine and diethyl chloromethylphosphonate are in a molar ratio of 1:0.9-1.1, and the weight ratio of ethylenediamine, anhydrous ethanol and petroleum ether is 1:8-12:5-7.

3. The waste ore-based water phosphorus removal agent according to claim 1, characterized in that: The molar ratio of the intermediate A, 2-chloroethanol and potassium carbonate (2) is 1:1-1.2:1.2-1.5, and the weight ratio of the intermediate A, anhydrous ethanol and deionized water is 1:8-12:5-7.

4. The waste ore-based water phosphorus removal agent according to claim 1, characterized in that: The molar ratio of the intermediate B (3), anthraquinone-2-carbonyl chloride and triethylamine is 1:1-1.2:1-1.2, and the weight ratio of the intermediate B, benzene and dilute hydrochloric acid is 1:8-12:3-5.

5. The waste ore-based water phosphorus removal agent according to claim 1, characterized in that: The concentration of the (3) dilute hydrochloric acid is 1 mol / L, the concentration of the sodium hydroxide solution is 1 mol / L, and the ethanol / water mixed solution refers to a mixture of ethanol and water in a weight ratio of 2:

3.

6. The method for preparing the waste ore-based water phosphorus removal agent according to any one of claims 1 to 5, characterized in that: The following steps are involved: S1. In a reactor, steel slag and red mud were added to deionized water. The reactor was sealed and heated to 280-320°C. Stirring was performed for 1-3 hours. The mixture was cooled to room temperature, filtered, washed, dried, and ball-milled through a 200-mesh sieve to obtain a steel slag / red mud mixture. S2. The steel slag / red mud mixture and zirconium oxychloride obtained in S1 were added to deionized water, heated to 50-70°C, stirred for 1-3 hours, cooled to room temperature, adjusted to pH 9-11 with sodium hydroxide solution, filtered and dried, and heated to 500-600°C in a muffle furnace and calcined for 2-4 hours to obtain a ZrO2-doped steel slag / red mud mixture; S3. The ZrO2-doped steel slag / red mud mixture obtained in S2 and the PNQE ligand were added to benzene, heated to 70-90 ° C, stirred for 4-6 hours, cooled to room temperature, filtered, washed with ethanol, and dried to obtain a steel slag / red mud mixture grafted with PNQE ligands; S4. The steel slag / red mud mixture grafted with PNQE ligands obtained in S3, lanthanum nitrate, cerium nitrate and ferric nitrate are added to deionized water, stirred at room temperature for 2-4 hours, and the pH is adjusted to 5-6 with dilute hydrochloric acid. The stirring is continued for 30-60 minutes, and the waste mineral-based water dephosphorus agent is obtained after filtering, washing and drying.

7. The method for preparing the waste ore-based water phosphorus removal agent according to claim 6, characterized in that: The weight ratio of the S1 steel slag to deionized water is 1:5-9.

8. The method for preparing the waste ore-based water phosphorus removal agent according to claim 6, characterized in that: The weight ratio of the S2 zirconium oxychloride and deionized water is 1:85-95, and the concentration of the sodium hydroxide solution is 1 mol / L.

9. The method for preparing the waste ore-based water phosphorus removal agent according to claim 6, characterized in that: The weight ratio of the S3 PNQE ligand to benzene is 1:27-31.

10. The method for preparing the waste ore-based water phosphorus removal agent according to claim 6, characterized in that: The weight ratio of the S4 lanthanum nitrate and deionized water is 1:180-220, and the concentration of dilute hydrochloric acid is 1 mol / L.

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