A low-temperature hydrothermal selective dephosphorization composite mineralizer for vanadium-containing ferrophosphorus and a hydrothermal strengthening method thereof
By using a low-temperature hydrothermal selective dephosphorization composite mineralizer, and by leveraging silicate network regulation and low-dose fluorine enhancement mechanisms, the problem of selective dephosphorization of vanadium-phosphorus-iron raw materials under high phosphorus conditions has been solved, achieving efficient, low-energy-consumption, and environmentally friendly vanadium resource recovery.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- SICHUAN UNIVERSITY OF SCIENCE AND ENGINEERING
- Filing Date
- 2026-03-16
- Publication Date
- 2026-06-09
Smart Images
Figure CN122168917A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of efficient separation and comprehensive utilization technology of metallurgical resources. Specifically, it relates to a selective hydrothermal dephosphorization composite mineralizer for vanadium-containing iron-phosphorus raw materials and its hydrothermal enhanced separation method. It is particularly suitable for low-temperature selective dephosphorization treatment of complex metal symbiotic raw materials containing high proportions of phosphorus (10-35%) and vanadium (3-18%). It is used to effectively remove phosphorus from vanadium-containing iron-phosphorus raw materials, while improving the recovery rate of vanadium and iron, reducing energy consumption, and avoiding fluorine pollution problems. Background Technology
[0002] The chemical composition of vanadium-containing ferrophosphorus, by mass percentage, is: V: 3-18%; P: 10-35%; Fe: 30-65%; Cr: 1-8%; Ni: 0.2-24%. This type of raw material often originates from intermediate products in high-phosphorus ferrophosphorus smelting, phosphorus-rich ferroalloys as a byproduct of vanadium metallurgy, and phosphorus-rich metal residues from special steel smelting. However, the processing of vanadium-containing ferrophosphorus presents significant technical challenges, such as: extremely high phosphorus content (up to 35%), the complex symbiotic structure formed by phosphorus and vanadium, and the tendency of vanadium to oxidize and migrate during dephosphorization. In particular, due to the symbiotic relationship between phosphorus and vanadium, traditional metallurgical methods lose a large amount of vanadium while removing phosphorus. Therefore, how to efficiently separate phosphorus while retaining vanadium resources has always been a technical challenge in the metallurgical industry.
[0003] Currently, the mainstream dephosphorization technologies in the industry mainly include three types: high-temperature converter method, conventional wet treatment method, and conventional hydrothermal method. All three methods have significant technical shortcomings and application limitations, as detailed below: High-temperature converter method is a traditional process for dephosphorizing and extracting vanadium from vanadium-containing molten iron. Chinese patent CN101302578A, "A Composite Vanadium Extraction and Dephosphorizing Agent for Vanadium-Containing Molten Iron and Its Preparation Method," discloses a composite vanadium extraction and dephosphorizing agent suitable for vanadium-containing molten iron and its preparation method. This technology and similar high-temperature converter processes all achieve dephosphorization and vanadium extraction by adding reagents such as iron oxide and lime to the molten iron in a high-temperature oxidizing environment above 1350℃. However, such processes generally suffer from high energy consumption, large vanadium loss (vanadium loss rate >10%), severe furnace lining erosion, and unsuitability for high-phosphorus materials. They are also highly dependent on high-temperature oxidation conditions and cannot solve the technical pain point of poor phosphorus phase selectivity, directly affecting the efficiency and effect of subsequent phosphorus and vanadium separation.
[0004] Conventional wet processing methods often directly use acid leaching to treat vanadium-phosphorus iron. Although this method can be implemented at low temperatures and does not require the construction of high-temperature smelting equipment, the leaching selectivity of vanadium, iron, and phosphorus is poor, and the simultaneous dissolution of V, Cr, and Ni is likely to occur. This not only leads to cumbersome and lengthy subsequent separation and purification steps for vanadium, iron, and phosphorus, but also consumes a large amount of acid reagents and generates difficult-to-treat phosphorus-containing wastewater during the production process, resulting in high environmental treatment pressure.
[0005] Conventional hydrothermal methods can complete dephosphorization reactions under medium and low temperature conditions, significantly reducing energy consumption compared to high-temperature converter methods. However, these processes generally require the addition of fluorides (such as CaF2) as fluxes to improve reaction efficiency. The use of fluorides can easily cause corrosion of production equipment, shorten equipment lifespan, and lead to environmental pollution. Furthermore, this method is only suitable for low-phosphorus systems; under high-phosphorus conditions, the dephosphorization rate drops sharply, relying heavily on CaF2 and exhibiting insufficient selectivity. Especially when the phosphorus content exceeds 15%, the dephosphorization rate of traditional hydrothermal systems is typically <80%, with vanadium loss >8%.
[0006] In summary, existing technologies for achieving efficient phosphorus removal and vanadium resource recovery suffer from problems such as high energy consumption, significant resource loss, and environmental pollution. Therefore, there is an urgent need for an enhanced hydrothermal system that can maintain high selectivity under high phosphorus conditions to achieve efficient, low-energy, and environmentally friendly phosphorus removal while maximizing the retention of vanadium and iron. Summary of the Invention
[0007] The core objective of this invention is to achieve selective dephosphorization under high phosphorus (10-35%) conditions; to inhibit the migration of elements such as vanadium, chromium, and nickel; to construct a low-temperature, highly selective hydrothermal system; and to establish a controllable interfacial reaction mechanism to achieve: a dephosphorization rate ≥92%, a vanadium loss rate ≤3%, a reaction temperature ≤220℃, and a stable system suitable for industrial scale-up.
[0008] To achieve the above-mentioned objectives, the present invention provides the following technical solution: This invention provides a low-temperature hydrothermal selective dephosphorization composite mineralizer for vanadium-containing iron phosphate, comprising the following raw material components in parts by weight: 80-95 parts of soluble silicate, 1-5 parts of fluoride, and 5-15 parts of pH buffer.
[0009] Preferably, the soluble silicate is sodium silicate and / or potassium silicate.
[0010] Preferably, the fluoride is calcium fluoride and / or sodium fluoride.
[0011] Preferably, the pH buffer is one or more of sodium bicarbonate, disodium hydrogen phosphate, and sodium carbonate, and the pH value of the pH buffer is 9-10.
[0012] Preferably, the raw material components include the following parts by weight: 65-75 parts silicate, 2-4 parts fluoride, and 8-12 parts pH buffer.
[0013] The present invention also provides a hydrothermal enhancement method for the low-temperature hydrothermal selective dephosphorization composite mineralizer for vanadium-containing iron phosphate, comprising the following steps: mixing vanadium-containing iron phosphate with the aforementioned low-temperature hydrothermal selective dephosphorization composite mineralizer for vanadium-containing iron phosphate, adding water to carry out a hydrothermal reaction, separating the solid and liquid phases to obtain a low-phosphorus vanadium-containing iron solid and a phosphorus-rich liquid phase.
[0014] Preferably, the amount of the low-temperature hydrothermal selective dephosphorization composite mineralizer for vanadium-containing ferrophosphorus is 10-15% of the mass of the vanadium-containing ferrophosphorus.
[0015] Preferably, the mass ratio of the mixture obtained after mixing to water is 1:0.1-4; the temperature of the hydrothermal reaction is 120-220℃; the pressure of the hydrothermal reaction is 0.5-3MPa; and the time of the hydrothermal reaction is 0.5-4h.
[0016] Preferably, the solid-liquid separation method is plate and frame filtration or centrifugation.
[0017] The present invention also provides the application of the aforementioned low-temperature hydrothermal selective dephosphorization composite mineralizer for vanadium-containing ferrophosphorus or the aforementioned hydrothermal enhancement method in improving the dephosphorization rate of vanadium-containing ferrophosphorus and reducing the vanadium loss rate of vanadium-containing ferrophosphorus.
[0018] The advantages of this invention compared to the prior art are as follows: The principle and innovation of this invention: The core innovation of this invention lies in the construction of a triple synergistic mechanism of "silicate network regulation + low-dose fluorine enhancement + pH stability window control".
[0019] (1) Silicate structure regulation mechanism Under hydrothermal conditions: Soluble silicates form a three-dimensional Si-O-Si network, which interacts with Ca. 2+ Competitive coordination disrupts the stable structure of apatite and reduces the binding energy of phosphorus in the crystal lattice. Results: → Promotes preferential phosphorus migration → Maintain the stability of the Fe-V main structure (2) Low-dose fluoride synergistic enhancement mechanism Unlike traditional methods that use large amounts of CaF2 as flux: This invention uses 1-5 parts of low-dose fluoride, which is only used for: entering the apatite lattice in trace amounts, inducing lattice distortion, improving the migration kinetic rate of P, without forming a high-fluoride system, and without generating fluoride wastewater problems.
[0020] (3) pH window locking mechanism Controlling the system pH to 9-10: Inhibiting V 5+ Formation of VO4 3- To prevent vanadium leaching and stabilize the Cr and Ni metal structures, this pH window is one of the key control parameters of this invention. Attached Figure Description
[0021] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0022] Figure 1 This is a process flow diagram of the dephosphorization treatment of the present invention; Figure 2 This is a diagram illustrating the mechanism of action of the composite mineralizer (low-temperature hydrothermal selective dephosphorization composite mineralizer), in which a silicate network encapsulates the phosphorus phase, fluoride ions directionally erode apatite, and a buffer maintains the pH balance at the interface. Detailed Implementation
[0023] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as a limitation of the present invention, but rather as a more detailed description of certain aspects, features, and embodiments of the present invention.
[0024] It should be understood that the terminology used in this invention is merely for describing particular embodiments and is not intended to limit the invention. Furthermore, with respect to numerical ranges in this invention, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Every smaller range between any stated value or intermediate value within a stated range, and any other stated value or intermediate value within said range, is also included in this invention. The upper and lower limits of these smaller ranges may be independently included or excluded from the range.
[0025] Unless otherwise stated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. While only preferred methods and materials have been described herein, any methods and materials similar or equivalent to those described herein may be used in the implementation or testing of this invention. All references to this specification are incorporated by way of citation to disclose and describe methods and / or materials associated with those references. In the event of any conflict with any incorporated reference, the content of this specification shall prevail.
[0026] Various modifications and variations can be made to the specific embodiments described in this specification without departing from the scope or spirit of the invention, as will be apparent to those skilled in the art. Other embodiments derived from this specification will also be apparent to those skilled in the art. This specification and embodiments are merely exemplary.
[0027] The terms “include,” “including,” “have,” “contain,” etc., used in this article are all open-ended terms, meaning that they include but are not limited to.
[0028] This invention provides a low-temperature hydrothermal selective dephosphorization composite mineralizer for vanadium-containing iron phosphate, comprising the following raw material components in parts by weight: 80-95 parts of soluble silicate, 1-5 parts of fluoride, and 5-15 parts of pH buffer.
[0029] In this invention, the low-temperature hydrothermal selective dephosphorization composite mineralizer for vanadium-phosphorus iron preferably comprises 85-90 parts of soluble silicate, more preferably 88 parts; the soluble silicate is preferably sodium silicate and / or potassium silicate; when the soluble silicate is sodium silicate and potassium silicate, the molar ratio of sodium silicate and potassium silicate is preferably 1-3:1, more preferably 2:1; the silicate can form a stable phosphate coating layer with phosphorus, inhibiting vanadium dissolution, and thus constituting a carrier framework for phosphorus selective migration.
[0030] In this invention, the low-temperature hydrothermal selective dephosphorization composite mineralizer for vanadium-containing iron preferably includes 2-4 parts of fluoride, more preferably 2.5-3.5 parts, and even more preferably 3 parts; the fluoride is preferably calcium fluoride and / or sodium fluoride; the fluoride can destroy the crystal structure of apatite and promote phosphorus diffusion, and its dosage is only 1 / 5 of that in the traditional process, which can significantly reduce the corrosive effect on equipment.
[0031] In this invention, the low-temperature hydrothermal selective dephosphorization composite mineralizer for vanadium-iron phosphate preferably includes 8-12 parts of a pH buffer, more preferably 9-11 parts, and even more preferably 10 parts; the pH buffer is preferably one or more of sodium bicarbonate, disodium hydrogen phosphate, and sodium carbonate, more preferably including sodium bicarbonate and / or disodium hydrogen phosphate; when the pH buffer is preferably sodium bicarbonate and sodium carbonate, the molar ratio of sodium bicarbonate and sodium carbonate is preferably 1-2:1-2, more preferably 1:1; the pH value of the pH buffer is preferably 9-10, more preferably 9.5; the pH buffer is used to maintain the pH of the system at 8-10, inhibit the formation of vanadate, and ensure the stability of the vanadium-iron phase.
[0032] The present invention also provides a hydrothermal enhancement method for the low-temperature hydrothermal selective dephosphorization composite mineralizer for vanadium-containing iron phosphate, comprising the following steps: mixing vanadium-containing iron phosphate with the aforementioned low-temperature hydrothermal selective dephosphorization composite mineralizer for vanadium-containing iron phosphate, adding water to carry out a hydrothermal reaction, separating the solid and liquid phases to obtain a low-phosphorus vanadium-containing iron solid and a phosphorus-rich liquid phase.
[0033] In this invention, the vanadium-containing ferrophosphorus is preferably vanadium-containing ferrophosphorus that has been crushed and dried. After crushing, it is preferably sieved through an 80-200 mesh sieve, more preferably 100-180 mesh, even more preferably 120-160 mesh, and still more preferably 150 mesh. The mass ratio of the mixture obtained after mixing to water is preferably 1:0.1-4, more preferably 1:1-3, and even more preferably 1:2. The amount of the composite mineralizer added is preferably 10-15% of the mass of the vanadium-containing ferrophosphorus, more preferably 12-14%, and even more preferably 13%. The temperature of the hydrothermal reaction is preferably 120-220℃, more preferably 150-210℃, and even more preferably 180-200℃. The pressure of the hydrothermal reaction is preferably 0.5-3 MPa, more preferably 1-2 MPa, and even more preferably 1.5 MPa. The time of the hydrothermal reaction is preferably 0.5-4 h, more preferably 1.5-3.5 h, and even more preferably 2-3 h. The solid-liquid separation method is preferably a plate and frame separator. The filter plates are preferably made of reinforced polypropylene or rubber-coated stainless steel, and the pressure of the plate and frame filter press is preferably 1.0~2.5MPa, more preferably 1.5~2MPa, and even more preferably 1.8MPa; the filtration cycle of the plate and frame filter press is preferably 1.5~3h, more preferably 2~2.5h, and even more preferably 2.2h; the frame thickness of the plate and frame filter press is preferably 16~80mm, more preferably 20~60mm, and even more preferably 3mm. The centrifugation process is preferably carried out using a horizontal decanter centrifuge, with a separation factor preferably ranging from 0 to 50 mm, more preferably from 2000 to 2500 G, and even more preferably from 2300 G. The centrifugation speed is preferably from 1500 to 4000 r / min, more preferably from 2000 to 3500 r / min, even more preferably from 2500 to 3000 r / min, and even more preferably from 2800 r / min.
[0034] The present invention also provides the application of the aforementioned low-temperature hydrothermal selective dephosphorization composite mineralizer for vanadium-containing ferrophosphorus or the aforementioned hydrothermal enhancement method in improving the dephosphorization rate of vanadium-containing ferrophosphorus and reducing the vanadium loss rate of vanadium-containing ferrophosphorus.
[0035] Example 1 A low-temperature hydrothermal selective dephosphorization composite mineralizer for vanadium-containing iron phosphorus is composed of 85% sodium silicate, 3% calcium fluoride, and 12% sodium bicarbonate and sodium carbonate (molar ratio 1:1).
[0036] Example 2 A low-temperature hydrothermal selective dephosphorization composite mineralizer for vanadium-containing iron phosphorus is composed of 86% sodium silicate and potassium silicate (molar ratio 2:1), 4% sodium fluoride, and 10% disodium hydrogen phosphate.
[0037] Example 3 A low-temperature hydrothermal selective dephosphorization composite mineralizer for vanadium-containing iron phosphorus is composed of 94% sodium silicate, 1% calcium fluoride, and 5% sodium carbonate.
[0038] Example 4 A hydrothermal enhancement method for a low-temperature hydrothermal selective dephosphorization composite mineralizer for vanadium-phosphorus iron comprises the following steps: The vanadium-containing ferrophosphorus is crushed, sieved through an 80-mesh sieve, and the composite mineralizer from Example 1 (added at 10% of the mass of the vanadium-containing ferrophosphorus) is added. The mixture is stirred to obtain a mixture. Water is added at a mass ratio of 1:2 between the mixture and water. The mixture is subjected to hydrothermal reaction at 120°C and 2.5 MPa for 3 hours, followed by plate and frame filtration (operating pressure: 1.0~2.5 MPa; filtration cycle: 1.5~3 hours; frame thickness: 16~80 mm; filter plate material: reinforced polypropylene) to obtain a low-phosphorus vanadium-containing ferrophosphorus solid and a phosphorus-rich liquid phase.
[0039] Example 5 A hydrothermal enhancement method for a low-temperature hydrothermal selective dephosphorization composite mineralizer for vanadium-phosphorus iron comprises the following steps: The vanadium-containing ferrophosphorus was crushed, sieved through a 200-mesh sieve, and the composite mineralizer from Example 2 (added at 12% of the mass of the vanadium-containing ferrophosphorus) was added. The mixture was mixed thoroughly to obtain a mixture. Water was added at a mass ratio of 1:0.1, and the mixture was subjected to a hydrothermal reaction at 220°C and 2.2 MPa for 3.5 hours. The mixture was then centrifuged (using a horizontal screw sedimentation centrifuge, separation factor: 1500-3000G), at a speed of 1500-4000 r / min) to obtain a low-phosphorus vanadium-containing ferrophosphorus solid and a phosphorus-rich liquid phase.
[0040] Example 6 A hydrothermal enhancement method for a low-temperature hydrothermal selective dephosphorization composite mineralizer for vanadium-phosphorus iron comprises the following steps: The vanadium-containing ferrophosphorus is crushed, sieved through a 140-mesh sieve, and the composite mineralizer from Example 3 (added at 15% of the mass of the vanadium-containing ferrophosphorus) is added. The mixture is stirred to obtain a mixture. Water is added at a mass ratio of 1:4 between the mixture and water. The mixture is subjected to hydrothermal reaction at 180°C and 3MPa for 2 hours, followed by plate and frame filtration (operating pressure: 1.0~2.5MPa; filtration cycle: 1.5~3 hours; frame thickness: 16~80mm; filter plate material: rubber-coated stainless steel) to obtain a low-phosphorus vanadium-containing ferrophosphorus solid and a phosphorus-rich liquid phase.
[0041] Comparative Example 1 Dephosphorization was performed according to the method in Example 4, except that "the composite mineralizer in Example 1" was replaced with "10% sodium bicarbonate solution".
[0042] Comparative Example 2 Dephosphorization was performed according to the method in Example 4, except that the "composite mineralizer in Example 1" was replaced with "a mineralizer containing 85% sodium silicate and 15% sodium bicarbonate and sodium carbonate (molar ratio 1:1)".
[0043] Comparative Example 3 The dephosphorization method follows the conventional hydrothermal method, but differs from the method in Example 4 in that the "composite mineralizer in Example 1" is replaced with "CaF2 solid" (added at 120% of the mass of vanadium-phosphorus iron), and the hydrothermal reaction temperature is 250°C.
[0044] Comparative Example 4 The dephosphorization method follows the conventional hydrothermal method, but differs from the method in Example 4 in that the "composite mineralizer in Example 1" is replaced with "CaF2 solid" (the amount added is 180% of the mass of vanadium-phosphorus iron), and the hydrothermal reaction temperature is 230°C.
[0045] Experimental Example 1 The dephosphorization effects of different methods in Examples 4-6 and Comparative Examples 1-4 on typical raw materials containing vanadium-containing ferrophosphorus (V 12%, P 20%, Fe 45%, Cr 3%, Ni 6%) were investigated. Specifically, the contents of phosphorus, vanadium, and chromium in unit mass of vanadium-containing ferrophosphorus before and after treatment were determined according to "SN / T 3319.1-2012 Import and Export Ferrophosphorus Part 1: Determination of Phosphorus, Manganese, Silicon, Titanium, Vanadium and Chromium by Inductively Coupled Plasma Atomic Emission Spectrometry". The contents of nickel in unit mass of vanadium-containing ferrophosphorus before and after treatment were determined according to "SN / T 5347.2-2021 Determination of Lead, Zinc, Phosphorus, Titanium and Nickel Content in Chromium Ore by Inductively Coupled Plasma Atomic Emission Spectrometry". The dephosphorization rate, vanadium loss rate, chromium loss rate, and nickel loss rate were calculated according to formulas 1, 2, 3, and 4. The results are shown in Table 1.
[0046] Dephosphorization rate = Phosphorus content per unit mass of vanadium-phosphorus iron after treatment / Phosphorus content per unit mass of vanadium-phosphorus iron before treatment (Formula 1); Vanadium loss rate = 1 - (vanadium content per unit mass of vanadium-containing ferrophosphate after treatment / vanadium content per unit mass of vanadium-containing ferrophosphate before treatment) Formula 2; Cr loss rate = 1 - (Cr content per unit mass of vanadium-phosphorus iron after treatment / Cr content per unit mass of vanadium-phosphorus iron before treatment) Formula 3; Ni loss rate = 1 - (Ni content per unit mass of vanadium-containing ferrophosphorus after treatment / Ni content per unit mass of vanadium-containing ferrophosphorus before treatment) Formula 4.
[0047] Table 1. Effects of different treatment methods on the dephosphorization efficiency of vanadium-containing iron phosphorus.
[0048] Table 1 shows that the composite mineralizer provided by this invention has a wide range of applicability. Furthermore, when using only sodium bicarbonate to treat vanadium-containing iron phosphate, the leaching selectivity is poor due to the pH value exceeding a specific range. Comparative Example 2 demonstrates the crucial promoting effect of fluoride on deep dephosphorization. Comparative Examples 3-4 illustrate that the effect of conventional hydrothermal dephosphorization is far inferior to this method.
[0049] Experimental Example 2 Typical raw materials containing vanadium-phosphorus iron (V 12%, P 20%, Fe 45%, Cr 3%, Ni 6%) were treated according to the hydrothermal enhancement method of this invention (Examples 4, 5, and 6); and the typical raw materials were treated using the conventional hydrothermal method (Comparative Examples 3 and 4). The results of dephosphorization rate, vanadium loss rate, chromium loss rate, and nickel loss rate in different treatment groups are summarized in Table 2 (calculated in the same way as in Experimental Example 1).
[0050] Table 2 Measurement Results
[0051] As shown in Table 2, under high P (≥20%) conditions, the composite mineralizer provided by this invention still maintains a dephosphorization rate of >90%.
[0052] As can be seen from the above embodiments, the present invention provides a low-temperature hydrothermal selective dephosphorization composite mineralizer for vanadium-containing ferrophosphorus and its hydrothermal enhancement method. Applying the low-temperature hydrothermal selective dephosphorization composite mineralizer of the present invention to the dephosphorization process of vanadium-containing ferrophosphorus can achieve a dephosphorization rate >92% and a vanadium retention rate >96% (vanadium retention rate = vanadium content per unit mass of vanadium-containing ferrophosphorus after treatment / vanadium content per unit mass of vanadium-containing ferrophosphorus before treatment). Simultaneously, the hydrothermal enhancement method provided by the present invention is a low-dose enhanced fluorine synergistic system, which can reduce the corrosion problem of fluorine elements on smelting equipment from the source and significantly reduce the generation of fluoride-containing wastewater, thereby reducing the cost of fluoride-containing wastewater treatment and the pollution to water bodies.
[0053] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.
Claims
1. A low-temperature hydrothermal selective dephosphorization composite mineralizer for vanadium-phosphorus iron, characterized in that, It includes the following raw material components in parts by weight: 80-95 parts soluble silicate, 1-5 parts fluoride, and 5-15 parts pH buffer.
2. The low-temperature hydrothermal selective dephosphorization composite mineralizer for vanadium-phosphorus iron according to claim 1, characterized in that, The soluble silicate is sodium silicate and / or potassium silicate.
3. The low-temperature hydrothermal selective dephosphorization composite mineralizer for vanadium-containing iron according to claim 1, characterized in that, The fluoride is calcium fluoride and / or sodium fluoride.
4. The low-temperature hydrothermal selective dephosphorization composite mineralizer for vanadium-containing iron phosphate according to claim 1, characterized in that, The pH buffer is one or more of sodium bicarbonate, disodium hydrogen phosphate, and sodium carbonate, and the pH value of the pH buffer is 9-10.
5. The low-temperature hydrothermal selective dephosphorization composite mineralizer for vanadium-containing iron according to claim 1, characterized in that, It includes the following raw material components in parts by weight: 65-75 parts silicate, 2-4 parts fluoride, and 8-12 parts pH buffer.
6. A hydrothermal enhancement method for a low-temperature hydrothermal selective dephosphorization composite mineralizer for vanadium-containing ferrophosphorus as described in any one of claims 1-5, characterized in that, Includes the following steps: The vanadium-containing ferrophosphorus is mixed with the low-temperature hydrothermal selective dephosphorization composite mineralizer for vanadium-containing ferrophosphorus as described in any one of claims 1-5, and water is added to carry out a hydrothermal reaction. Solid-liquid separation is performed to obtain a low-phosphorus vanadium-containing ferrophosphorus solid and a phosphorus-rich liquid phase.
7. The hydrothermal enhancement method according to claim 6, characterized in that, The amount of the low-temperature hydrothermal selective dephosphorization composite mineralizer used for vanadium-containing ferrophosphorus is 10-15% of the mass of the vanadium-containing ferrophosphorus.
8. The hydrothermal enhancement method according to claim 6, characterized in that, The mass ratio of the mixture obtained after mixing to water is 1:0.1-4; the temperature of the hydrothermal reaction is 120-220℃; the pressure of the hydrothermal reaction is 0.5-3MPa; and the time of the hydrothermal reaction is 0.5-4h.
9. The hydrothermal enhancement method according to claim 6, characterized in that, The solid-liquid separation method is plate and frame filtration or centrifugation.
10. The application of the low-temperature hydrothermal selective dephosphorization composite mineralizer for vanadium-containing ferrophosphorus as described in any one of claims 1-5, or the hydrothermal enhancement method as described in any one of claims 6-9, in improving the dephosphorization rate and reducing the vanadium loss rate of vanadium-containing ferrophosphorus.