Method for increasing vanadium content in converter vanadium slag

Abstract

The method for improving the content of vanadium in converter vanadium slag disclosed by the embodiment of the application comprises the following steps: S1, vanadium-containing molten iron is blown oxygen smelted in a converter by adding a dephosphorizing agent and a cooling agent to obtain molten vanadium slag and semi-steel; wherein the P content in the semi-steel is lower than 0.005wt%; the CaO content in the molten vanadium slag is greater than 5wt%, and the P content is greater than 0.05wt%; S2, a high-valence oxide-containing material is added into the obtained molten vanadium slag, CO2-O2 gas is introduced for stirring, and reaction is carried out at a set temperature; during the reaction, the reaction process is synergistically strengthened by using ultrasound, microwave and a magnetic field, and a magnetic vanadium spinel and a molten silicate mixture are obtained by the reaction; the content of the magnetic solid vanadium spinel is 20-100wt%; S3, the magnetic vanadium spinel and the molten silicate mixture are separated under the condition of a magnetic field to obtain the magnetic vanadium spinel and the molten silicate, respectively.

Description

Technical Field

[0001] This invention belongs to the field of iron and steel smelting technology, specifically relating to a method for increasing the vanadium content in converter vanadium slag. Background Technology

[0002] Vanadium has important applications in industries such as steel, batteries, and catalysts. Chromium can improve the oxidation resistance and corrosion resistance of steel and is an important alloying element in heat-resistant steel.

[0003] Vanadium-titanium magnetite is a complex symbiotic mineral rich in various valuable components such as iron, vanadium, chromium, and titanium. Vanadium slag contains valuable metals vanadium and chromium. The V₂O₃ content in vanadium slag is 13–19 wt.%. The main phases of vanadium slag are spinel phase (vanadium-iron spinel, manganese-vanadium spinel, and ilmenite spinel), silicate phase (manganese-iron olivine), and metallic iron phase; vanadium mainly exists in the trivalent form in vanadium-iron spinel (FeV₂O₄).

[0004] Patent CN201310416429.4 discloses a method for separating vanadium resources from vanadium slag using centrifugation at 1240-1260℃, which involves separating the spinel phase and silicate phase from molten vanadium slag using centrifugation and centrifugation. Patent CN201610807157.4 discloses a method for dephosphorizing vanadium-containing molten iron in a vanadium-extraction converter, which involves controlling the oxygen lance and adding iron oxide scale for dephosphorization. Patent CN201210239175.9 discloses a method for simultaneous dephosphorization and vanadium extraction in a converter, which involves adding lime as a dephosphorizing agent to the vanadium-containing molten iron in the converter during the vanadium extraction process. Patent CN201210238253.3 discloses a coolant and production method for dephosphorization and vanadium extraction in a converter, which involves mixing sodium salt, iron oxide scale, bauxite powder, and water to form a mixture, which is then baked to remove moisture, resulting in cold-formed pellets.

[0005] However, existing vanadium oxide production processes require the CaO content of vanadium slag to be less than 2.5%, which prevents the addition of calcium oxide for dephosphorization during vanadium extraction from vanadium-containing molten iron in converters. This results in phosphorus from the molten iron entering the semi-steel, which is detrimental to the production of high-value-added clean steel. Adding calcium for dephosphorization yields high-calcium, high-phosphorus vanadium slag. During leaching, vanadium and phosphorus easily combine to form vanadium-phosphovanadium heteropolyacids and other phosphate precipitates, hindering vanadium precipitation, significantly reducing the vanadium precipitation rate, and affecting vanadium quality. In sodium roasting and water leaching processes, the phosphorus concentration is controlled below 0.015 g / L. In calcination roasting and acid leaching processes, the phosphorus concentration is controlled below 0.06 g / L. Currently, due to the high phosphorus content requirements of the roasting and leaching processes, simultaneous vanadium extraction and dephosphorization during converter vanadium extraction is difficult. Summary of the Invention

[0006] In view of this, embodiments of the present invention disclose a method for increasing the vanadium content in converter vanadium slag, proposing simultaneous vanadium extraction and dephosphorization in the converter, followed by selective oxidation of the molten vanadium slag to prepare magnetic vanadium spinel, further realizing the separation of vanadium spinel from phosphorus and silicate phases. The separated vanadium spinel has low phosphorus content and high vanadium content, which can avoid the problem of difficult dephosphorization in the later stage.

[0007] Some embodiments disclose methods for increasing the vanadium content in converter vanadium slag, including the steps of:

[0008] S1. Vanadium-containing molten iron is smelted in a converter using oxygen blowing. During the smelting process, a dephosphorizing agent and a coolant are added to obtain molten vanadium slag and semi-steel. The contents of each component in the vanadium-containing molten iron are as follows: C 3.5-4.8 wt%, Si 0.01-0.36 wt%, Ti 0.01-0.32 wt%, P 0.01-0.1 wt%, V 0.05-0.5 wt%, and Cr 0-0.5 wt%. The P content in the semi-steel is less than 0.003 wt%. The CaO content in the molten vanadium slag is greater than 5 wt%, and the P content is greater than 0.05 wt%.

[0009] S2. Add materials containing high-valence oxides to the obtained molten vanadium slag, introduce CO2-O2 gas and stir, and react at a set temperature; during the reaction, use ultrasound, microwave and magnetic field to enhance the reaction process in a coordinated manner to obtain a mixture of magnetic solid vanadium spinel and molten liquid silicate; the content of magnetic solid vanadium spinel is 20-100 wt%.

[0010] S3, a mixture of magnetic solid vanadium spinel and molten solid silicate, is separated under a magnetic field to obtain magnetic vanadium spinel and molten silicate, respectively.

[0011] Furthermore, some embodiments of the method for increasing the vanadium content in converter vanadium slag also include the step of:

[0012] S4. The obtained molten liquid silicate is cooled and added to the converter as a coolant to realize the recycling of iron.

[0013] Some embodiments disclose methods for increasing the vanadium content in converter vanadium slag, wherein the dephosphorizing agent includes one or more of CaO, CaCO3, Na2CO3, MgO, Al2O3, and CaF2, and the coolant includes silicates.

[0014] In some embodiments of the method for increasing the vanadium content in converter vanadium slag, step S2 is characterized by setting the temperature to 1000–1600°C and the CO2–O2 gas flow rate to 0–12 m³ / ton of vanadium slag. 3 Materials containing high-valence oxides include MnO2, Mn2O3, Fe3O4, Fe2VO4, CeO2, and nanoscale core-shell structure Fe2O3@CeO2.

[0015] In some embodiments of the method for increasing the vanadium content in converter vanadium slag, in step S3, magnetic solid vanadium spinel and molten liquid silicate mixture are separated at a temperature of 1000–1600°C.

[0016] Some embodiments disclose methods for increasing the vanadium content in converter vanadium slag, wherein the amount of dephosphorizing agent added is 10-40 kg / ton of vanadium-containing molten iron, and the amount of coolant added is 10-70 kg / ton of vanadium-containing molten iron.

[0017] Some embodiments disclose a method for increasing the vanadium content in converter vanadium slag. In step S2, ultrasonic heating is used in the initial mixing stage of the slag, with the ultrasonic intensity set to 20-40 kHz; microwave heating is used in the middle stage of the reaction, with the microwave frequency set to 2.45 GHz; and magnetic field heating is used in the later stage of the reaction, with the magnetic field intensity set to 0.1-0.5 T.

[0018] Some embodiments disclose methods for increasing the vanadium content in converter vanadium slag, wherein the high-valence oxide material is a combination of MnO2 or Mn2O3, Fe3O4 or Fe2VO4; or a combination of MnO2 or Mn2O3, Fe3O4 or Fe2VO4 and CeO2; or a nanoscale core-shell structure Fe2O3@CeO2.

[0019] In some embodiments of the method for increasing the vanadium content in converter vanadium slag, in step S3, the magnetic field strength is set to 0.1 to 0.5 T.

[0020] The method for increasing the vanadium content in converter vanadium slag disclosed in this invention has the following beneficial technical effects:

[0021] (1) Vanadium slag is obtained by simultaneously removing vanadium and phosphorus. The phosphorus content in the semi-steel is less than 0.003 wt%. Vanadium spinel is initially separated from the molten slag phase by a dephosphorizing agent. Then, the spinel is transformed into magnetic vanadium spinel by selective oxidation. Further separation is achieved by magnetic separation. Through two-step slag adjustment, 95% of the phosphorus in phosphogypsum and spinel enters the silicate phase. The phosphorus content in the obtained vanadium spinel is less than 0.003 wt%.

[0022] (2) Traditionally, vanadium slag has low V2O5 content. The new method enables the direct production of magnetic vanadium spinel with high vanadium content and low silicon content.

[0023] (3) The silicate obtained from the reaction is added to the converter as a coolant to realize the recycling of iron and greatly reduce the iron content in the tailings. The silicate phase is added to the vanadium extraction converter as a coolant to further recover iron and vanadium in the silicate and reduce the iron and vanadium content in the tailings.

[0024] (4) Unlike the traditional method of separating spinel and olivine in vanadium slag by supergravity, the magnetic separation of magnetic vanadium spinel and molten silicate is achieved by converting FeV2O4 into Fe2VO4.

[0025] (5) Compared with magnetic enrichment of vanadium in coal shale, where vanadium forms magnetic substances through solid-solid reactions and Fe2O3 and V2O3 readily yield Fe2VO4, the process for enriching vanadium in coal shale emphasizes avoiding excessively high temperatures that could cause sintering. Magnetic enrichment of coal shale separates magnetic and non-magnetic substances through ball milling at low temperatures. The new method forms magnetic substances in liquid silicates through precipitation, with a completely different reaction mechanism and formation process; the separation process is simple and does not require additional ball milling or other processes; through vanadium extraction and dephosphorization, and magnetic separation, phosphorus remains in the silicate phase, while the enriched vanadium-iron spinel is phosphorus-free and can be directly used for vanadium extraction.

[0026] (6) By controlling the composition and magnetism, V2O3 is preferentially precipitated, and then Fe2VO4 is used to encapsulate V2O3, or magnetic materials such as Fe2VO4 and Fe3O4 are added to encapsulate the precipitated V2O3, so as to achieve magnetic separation and obtain a solid phase with high V2O3 content; CeO2 can be used as an oxidant or as a material to enhance the magnetic properties of the solid phase to achieve separation.

[0027] (7) The appearance of the apatite phase leads to an increase in the phosphorus content in the spinel phase. By controlling the slag system with sodium carbonate, the apatite precipitated in the slag is converted into the molten liquid phase, thereby controlling the phosphorus to enter the liquid phase in the slag and reducing the phosphorus content in the spinel phase.

[0028] (8) By combining the technologies of multi-physics field enhanced reaction, high-temperature in-situ separation and phosphorus directional recycling, the problems of low vanadium recovery rate, serious phosphorus pollution and high energy consumption can be solved.

[0029] (9) The synergistic control of multiple physical fields such as ultrasound, microwave and magnetic field, with ultrasound at a frequency of 20 to 40 kHz preferentially acts on the initial mixing stage of slag to break up high-valence oxide particles; microwave selectively heats FeV2O4 in the middle of the reaction to promote the conversion to Fe2VO4; magnetic field guides the directional growth of vanadium spinel in the later stage of the reaction to promote the separation of vanadium and silicon; the resulting particle size is concentrated at about 50 μm.

[0030] (10) Dynamic adjustment of the CO2-O2 gas ratio: The CO2 / O2 ratio is adjusted in real time according to the slag temperature to avoid the over-oxidation of vanadium to V2O5, while inhibiting Fe. 3+ Over-generation.

[0031] (11) Add nano-sized Fe2O3@CeO2 core-shell structure catalyst with a particle size of 20-50 nm. Utilize the oxygen vacancies in CeO2 to promote CO2 activation and reduce V. 4+ Transform into V3+ The activation energy is reduced, the reaction time is shortened by 30%, and the vanadium recovery rate is increased to over 95%. Detailed Implementation

[0032] The term "embodiment" used herein, as an example, is not necessarily to be construed as superior to or better than other embodiments. Performance testing in these embodiments of the invention, unless otherwise specified, employs conventional testing methods in the art. It should be understood that the terminology used in these embodiments is merely for describing particular implementations and is not intended to limit the scope of the disclosure of these embodiments.

[0033] Unless otherwise stated, the technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the embodiments of this invention pertain; other experimental methods and technical means not specifically noted in the embodiments of this invention refer to experimental methods and technical means commonly used by one of ordinary skill in the art.

[0034] The terms “basic” and “approximately” used in this document are to describe small fluctuations. For example, they can mean less than or equal to ±5%, such as less than or equal to ±2%, such as less than or equal to ±1%, such as less than or equal to ±0.5%, such as less than or equal to ±0.2%, such as less than or equal to ±0.1%, such as less than or equal to ±0.05%. Numerical data presented or expressed in range format in this document are used for convenience and brevity only, and should therefore be flexibly interpreted to include not only the explicitly listed values ​​that define the range, but also all independent values ​​or subranges contained within that range. For example, a numerical range of “1–5%” should be interpreted to include not only the explicitly listed values ​​from 1% to 5%, but also the independent values ​​and subranges within the indicated range. Thus, this numerical range includes independent values ​​such as 2%, 3.5%, and 4%, and subranges such as 1%–3%, 2%–4%, and 3%–5%, etc. This principle also applies to ranges that list only one value. Furthermore, this interpretation applies regardless of the width of the range or the characteristics described.

[0035] In this document, including in the claims, conjunctions such as "comprising," "including," "with," "having," "containing," "involving," and "accommodating" are understood to be open-ended, meaning "including but not limited to." Only the conjunctions "consisting of" and "composed of" are closed conjunctions.

[0036] To better illustrate the content of this invention, numerous specific details are provided in the following detailed embodiments. Those skilled in the art should understand that the invention can be practiced even without certain specific details. In the embodiments, some methods, means, instruments, and devices well-known to those skilled in the art are not described in detail, in order to highlight the main points of the invention.

[0037] Without conflict, the technical features disclosed in the embodiments of the present invention can be combined arbitrarily, and the resulting technical solution belongs to the content disclosed in the embodiments of the present invention.

[0038] In some embodiments, the method for increasing the vanadium content in converter vanadium slag includes the steps of:

[0039] S1. Vanadium-containing molten iron is smelted in a converter using oxygen blowing. During the smelting process, a dephosphorizing agent and a coolant are added to obtain molten vanadium slag and semi-steel. The vanadium-containing molten iron, by mass, contains the following components: C 3.5–4.8%, Si 0.01–0.36%, Ti 0.01–0.32%, P 0.01–0.1%, V 0.05–0.5%, and Cr 0–0.5%. The semi-steel contains less than 0.003% P. The molten vanadium slag contains more than 5% CaO and more than 0.05% P.

[0040] Typically, dephosphorizing agents are used to remove phosphorus from vanadium-containing molten iron, converting the phosphorus into apatite and spinel. The converted apatite and spinel are then incorporated into the silicate phase. Generally, the amount of dephosphorizing agent added is 10–40 kg / ton of vanadium-containing molten iron. Coolant does not participate in the reaction but is used to lower the temperature of the reaction melt to increase the oxidation rate of vanadium. Generally, the amount of coolant added is 10–70 kg / ton of vanadium-containing molten iron.

[0041] S2. Add materials containing high-valence oxides to the obtained molten vanadium slag, introduce CO2-O2 gas and stir, react at a set temperature to obtain a mixture of magnetic solid vanadium spinel and molten liquid silicate; the content of magnetic vanadium spinel in the mixture is 20-100 wt%.

[0042] Generally, the obtained magnetic vanadium spinel contains the following components: 20-45 wt% V2O3, 0-11 wt% Cr2O3, 0.5-5 wt% SiO2, 0-0.08 wt% P, 20-45 wt% FeO, 6-12 wt% MnO, and 8-12 wt% TiO2.

[0043] The molten silicate contains the following components: 27–35 wt% SiO2, 8–15 wt% TiO2, and 4–20 wt% CaO;

[0044] S3. A mixture of magnetic solid vanadium spinel and molten liquid silicate is separated under a magnetic field to obtain magnetic vanadium spinel and molten silicate, respectively; generally, the magnetic field strength is set between 0.1 and 0.5 T.

[0045] S4. The obtained molten silicate is cooled and added to a converter as a coolant to achieve iron recycling. Typically, the TFe content in the tailings obtained by the method disclosed in this embodiment can be reduced by more than 30 wt% compared with the TFe content in conventional processes.

[0046] Some embodiments disclose methods for increasing the vanadium content in converter vanadium slag, wherein the dephosphorizing agent includes one or more of CaO, CaCO3, Na2CO3, MgO, Al2O3, and CaF2, and the coolant includes silicates.

[0047] In some embodiments of the method for increasing the vanadium content in converter vanadium slag, step S2 is characterized by setting the temperature to 1000–1600°C and the CO2–O2 gas flow rate to 0–12 m³ / ton of vanadium slag. 3 Materials containing high-valence oxides include MnO2, Mn2O3, Fe3O4, Fe2VO4, or CeO2. Among them, MnO2 and Mn2O3 have oxidizing effects, while Fe3O4, Fe2VO4, and CeO2 have magnetic enhancement effects; the nanoscale core-shell structure Fe2O3@CeO2 has both oxidizing and magnetic enhancement effects.

[0048] In some embodiments, the high-valence oxide material is preferably a combination of MnO2 or Mn2O3, Fe3O4 or Fe2VO4. For example, a combination of MnO2 and Fe3O4, or a combination of Mn2O3 and Fe2VO4. Generally, in the combination of MnO2 or Mn2O3, Fe3O4 or Fe2VO4, the mass ratio of the two is 4-6:4-6.

[0049] In some embodiments, the high-valence oxide material is further preferably a combination of MnO2 or Mn2O3, Fe3O4 or Fe2VO4, and CeO2. For example, a combination of MnO2, Fe3O4, and CeO2, or MnO 2、 The combination of Fe2VO4 and CeO2. Generally, in the combination of MnO2 or Mn2O3, Fe3O4 or Fe2VO4 and CeO2, the mass ratio of the three is 3-5:3-4:1-2.

[0050] Furthermore, in some embodiments, the nanoscale core-shell structure Fe2O3@CeO2 is more preferably used for materials containing high-valence oxides.

[0051] In some embodiments of the method for increasing the vanadium content in converter vanadium slag, step S3 involves separating the magnetic solid vanadium spinel and the molten silicate mixture at a temperature of 1000–1600°C.

[0052] The technical details are further illustrated below with reference to the embodiments.

[0053] Example 1

[0054] In Example 1, the method for increasing the vanadium content in converter vanadium slag includes:

[0055] S1. Vanadium-containing molten iron (of which, by mass, C is 4.4%, Si is 0.2%, Ti is 0.2%, P is 0.05%, V is 0.35%, and Cr is 0.2%) is smelted in a converter with oxygen blowing. During the smelting process, a dephosphorizing agent and a coolant are added to obtain molten vanadium slag and semi-steel. The vanadium-containing molten iron is 200t, the oxygen blowing temperature is 1290℃, the oxygen blowing time is 5 minutes, the dephosphorizing agent CaO is 5t, and the coolant silicate is 10t.

[0056] S2. Add 0.01t of MnO2 to the obtained molten vanadium slag, introduce CO2-O2 gas and stir, heat to a set temperature to react, and obtain a mixture of magnetic solid vanadium spinel and molten liquid silicate; the ratio of CO2 to O2 in the CO2-O2 gas is 10:1, and the total flow rate is 50m³ / h. 3 The reaction time was 10 minutes, and the set temperature was 1350℃.

[0057] S3. A mixture of magnetic solid vanadium spinel and molten liquid silicate was separated under a magnetic field to obtain magnetic solid vanadium spinel and molten liquid silicate, respectively. The molten liquid silicate was poured out to obtain the solid Fe2VO4 phase. The magnetic field strength was 0.2T.

[0058] Example 2

[0059] In Example 2, the method for increasing the vanadium content in converter vanadium slag includes:

[0060] S1. Vanadium-containing molten iron (of which, by mass, C is 4.4%, Si is 0.2%, Ti is 0.2%, P is 0.05%, V is 0.35%, and Cr is 0.2%) is smelted in a converter with oxygen blowing. During the smelting process, a dephosphorizing agent and a coolant are added to obtain molten vanadium slag and semi-steel. The vanadium-containing molten iron is 200t, the oxygen blowing temperature is 1290℃, the oxygen blowing time is 5 minutes, the dephosphorizing agent CaO is 5t, and the coolant silicate is 10t.

[0061] S2. Add 0.01t of Mn2O3 to the obtained molten vanadium slag, introduce CO2-O2 gas and stir, heat to a set temperature to react, and obtain a mixture of magnetic solid vanadium spinel and molten liquid silicate; the ratio of CO2 to O2 in the CO2-O2 gas is 10:1, and the total flow rate is 50m³ / h. 3 The reaction time was 10 minutes, and the set temperature was 1350℃.

[0062] S3. A mixture of magnetic solid vanadium spinel and molten liquid silicate was separated under a magnetic field to obtain magnetic solid vanadium spinel and molten liquid silicate, respectively. The molten liquid silicate was then poured out to obtain the solid Fe2VO4 phase. The magnetic field strength was 0.5T.

[0063] Example 3

[0064] In Example 3, the method for increasing the vanadium content in converter vanadium slag includes:

[0065] S1. Vanadium-containing molten iron (of which, by mass, C is 4.4%, Si is 0.2%, Ti is 0.2%, P is 0.05%, V is 0.35%, and Cr is 0.2%) is smelted in a converter with oxygen blowing. During the smelting process, a dephosphorizing agent and a coolant are added to obtain molten vanadium slag and semi-steel. The vanadium-containing molten iron is 200t, the oxygen blowing temperature is 1290℃, the oxygen blowing time is 5 minutes, the dephosphorizing agent Na2CO3 is 5t, and the coolant silicate is 10t.

[0066] S2. Add 0.01t of Fe3O4 to the obtained molten vanadium slag, introduce CO2-O2 gas and stir, heat to a set temperature to react, and obtain a mixture of magnetic solid vanadium spinel and molten liquid silicate; the ratio of CO2 to O2 in the CO2-O2 gas is 10:1, and the total flow rate is 50m³ / h. 3 The reaction time was 10 minutes, and the set temperature was 1350℃.

[0067] S3. A mixture of magnetic solid vanadium spinel and molten liquid silicate was separated under a magnetic field to obtain magnetic solid vanadium spinel and molten liquid silicate, respectively. The molten liquid silicate was poured out to obtain the solid Fe2VO4 phase. The magnetic field strength was 0.2T.

[0068] Example 4

[0069] In Example 4, the method for increasing the vanadium content in converter vanadium slag includes:

[0070] S1. Vanadium-containing molten iron (of which, by mass, C is 4.4%, Si is 0.2%, Ti is 0.2%, P is 0.05%, and V is 0.35%) is smelted in a converter with oxygen blowing. During the smelting process, a dephosphorizing agent and a coolant are added to obtain molten vanadium slag and semi-steel. The amount of vanadium-containing molten iron is 200t, the oxygen blowing temperature is 1290℃, the oxygen blowing time is 5 minutes, the dephosphorizing agent Na2CO3 is 5t, and the coolant silicate is 10t.

[0071] S2. Add 0.06t of Fe2VO4 and 0.04t of Mn2O to the obtained molten vanadium slag. 3，A mixture of CO2-O2 gas and stirring was introduced and heated to a set temperature for reaction. Ultrasound was introduced during the initial stirring process, with an intensity set to 200 kHz, to obtain a mixture of magnetic solid vanadium spinel and molten liquid silicate. The ratio of CO2 to O2 in the CO2-O2 gas was 10:1, and the total flow rate was 50 m³ / s. 3 The reaction time was 6 minutes, and the set temperature was 1350℃.

[0072] S3. A mixture of magnetic solid vanadium spinel and molten liquid silicate was separated under a magnetic field to obtain magnetic solid vanadium spinel and molten liquid silicate, respectively. The molten liquid silicate was poured out to obtain the solid Fe2VO4 phase. The magnetic field strength was 0.2T.

[0073] Example 5

[0074] In Example 5, the method for increasing the vanadium content in converter vanadium slag includes:

[0075] S1. Vanadium-containing molten iron (of which, by mass, C is 4.4%, Si is 0.2%, Ti is 0.2%, P is 0.05%, and V is 0.35%) is smelted in a converter with oxygen blowing. During the smelting process, a dephosphorizing agent and a coolant are added to obtain molten vanadium slag and semi-steel. The amount of vanadium-containing molten iron is 200t, the oxygen blowing temperature is 1290℃, the oxygen blowing time is 5 minutes, the dephosphorizing agent Na2CO3 is 5t, and the coolant silicate is 10t.

[0076] S2. Add 0.05t of Fe2VO4 and 0.05t of MnO2 to the obtained molten vanadium slag, introduce CO2-O2 gas and stir, heat to a set temperature for reaction, apply a magnetic field during the later stages of the reaction (magnetic field strength set at 0.1T), and obtain a mixture of magnetic solid vanadium spinel and molten liquid silicate; the ratio of CO2 to O2 in the CO2-O2 gas is 10:1, and the total flow rate is 50m³. 3 The reaction time was 5 minutes, and the set temperature was 1350℃.

[0077] S3. A mixture of magnetic solid vanadium spinel and molten liquid silicate was separated under a magnetic field to obtain magnetic solid vanadium spinel and molten liquid silicate, respectively. The molten liquid silicate was poured out to obtain the solid Fe2VO4 phase. The magnetic field strength was 0.2T.

[0078] Example 6

[0079] In Example 6, the method for increasing the vanadium content in converter vanadium slag includes:

[0080] S1. Vanadium-containing molten iron (of which, by mass, C is 4.4%, Si is 0.2%, Ti is 0.2%, P is 0.05%, and V is 0.35%) is smelted in a converter with oxygen blowing. During the smelting process, a dephosphorizing agent and a coolant are added to obtain molten vanadium slag and semi-steel. The amount of vanadium-containing molten iron is 200t, the oxygen blowing temperature is 1290℃, the oxygen blowing time is 5 minutes, the dephosphorizing agent Na2CO3 is 5t, and the coolant silicate is 10t.

[0081] S2. Add 0.04 t Fe₂VO₄, 0.04 t MnO₂, and 0.01 t CeO₂ to the obtained molten vanadium slag, then introduce CO₂-O₂ gas and stir. Heat to a set temperature and react for 2 minutes, then react under magnetic conditions for 5 minutes to obtain a mixture of magnetic solid vanadium spinel and molten liquid silicate. The ratio of CO₂ to O₂ in the CO₂-O₂ gas is 10:1, and the total flow rate is 50 m³ / s. 3 The reaction time was 5 minutes, and the temperature was set at 1350℃.

[0082] S3. A mixture of magnetic solid vanadium spinel and molten liquid silicate was separated under a magnetic field to obtain magnetic solid vanadium spinel and molten liquid silicate, respectively. The molten liquid silicate was poured out to obtain the solid Fe2VO4 phase. The magnetic field strength was 0.2T.

[0083] Example 7

[0084] In Example 7, the method for increasing the vanadium content in converter vanadium slag includes:

[0085] S1. Vanadium-containing molten iron (of which, by mass, C is 4.4%, Si is 0.2%, Ti is 0.2%, P is 0.05%, and V is 0.35%) is smelted in a converter with oxygen blowing. During the smelting process, a dephosphorizing agent and a coolant are added to obtain molten vanadium slag and semi-steel. The amount of vanadium-containing molten iron is 200t, the oxygen blowing temperature is 1290℃, the oxygen blowing time is 5 minutes, the dephosphorizing agent Na2CO3 is 5t, and the coolant silicate is 10t.

[0086] S2. Add 0.01 t of Fe2O3@CeO2 core-shell catalyst (particle size 20 nm) to the obtained molten vanadium slag. Stir the mixture with CO2-O2 gas and heat to a set temperature for 2 min. Then react under magnetic conditions for 5 min to obtain a mixture of magnetic solid vanadium spinel and molten liquid silicate. The ratio of CO2 to O2 in the CO2-O2 gas is 10:1, and the total flow rate is 50 m³ / min. 3 The reaction time was 5 minutes, and the temperature was set at 1350℃.

[0087] S3. A mixture of magnetic solid vanadium spinel and molten liquid silicate was separated under a magnetic field to obtain magnetic solid vanadium spinel and molten liquid silicate, respectively. The molten liquid silicate was poured out to obtain the solid Fe2VO4 phase. The magnetic field strength was 0.2T.

[0088] Example 8

[0089] In Example 8, the method for increasing the vanadium content in converter vanadium slag includes:

[0090] S1. Vanadium-containing molten iron (of which, by mass, C is 4.4%, Si is 0.2%, Ti is 0.2%, P is 0.05%, V is 0.35%, and Cr is 0.2%) is smelted in a converter with oxygen blowing. During the smelting process, a dephosphorizing agent and a coolant are added to obtain molten vanadium slag and semi-steel. The vanadium-containing molten iron is 200t, the oxygen blowing temperature is 1290℃, the oxygen blowing time is 5 minutes, the dephosphorizing agent Na2CO3 is 5t, and the coolant silicate is 10t.

[0091] S2. To the obtained molten vanadium slag, add 0.04t of Fe2VO4, 0.04t of MnO2, and 0.02t of CeO2. Purge with CO2-O2 gas and stir. Heat to a set temperature and react for 2 minutes, then react under magnetic conditions for 5 minutes to obtain a mixture of magnetic solid vanadium spinel and molten liquid silicate. The ratio of CO2 to O2 in the CO2-O2 gas is 10:1, and the total flow rate is 50 m³ / s. 3 The reaction time was 5 minutes, and the temperature was set at 1350℃.

[0092] S3. A mixture of magnetic solid vanadium spinel and molten liquid silicate was separated under a magnetic field to obtain magnetic solid vanadium spinel and molten liquid silicate, respectively. The molten liquid silicate was poured out to obtain the solid Fe2VO4 phase. The magnetic field strength was 0.2T.

[0093] Example 9

[0094] In Example 9, the method for increasing the vanadium content in converter vanadium slag includes:

[0095] S1. Vanadium-containing molten iron (of which, by mass, C is 4.4%, Si is 0.2%, Ti is 0.2%, P is 0.05%, V is 0.35%, and Cr is 0.2%) is smelted in a converter with oxygen blowing. During the smelting process, a dephosphorizing agent and a coolant are added to obtain molten vanadium slag and semi-steel. The vanadium-containing molten iron is 200t, the oxygen blowing temperature is 1290℃, the oxygen blowing time is 5 minutes, the dephosphorizing agent Na2CO3 is 5t, and the coolant silicate is 10t.

[0096] S2. To the obtained molten vanadium slag, add 0.04t of Fe2VO4, 0.04t of MnO2, and 0.02t of CeO2. Purge with CO2-O2 gas and stir. Heat to a set temperature and react for 2 minutes, then react under magnetic conditions for 5 minutes to obtain a mixture of magnetic solid vanadium spinel and molten liquid silicate. The ratio of CO2 to O2 in the CO2-O2 gas is 10:1, and the total flow rate is 50 m³ / s. 3 The reaction time was 5 minutes, and the temperature was set at 1350℃.

[0097] S3. A mixture of magnetic solid vanadium spinel and molten liquid silicate was separated under a magnetic field to obtain magnetic solid vanadium spinel and molten liquid silicate, respectively. The molten liquid silicate was poured out to obtain the solid Fe2VO4 phase. The magnetic field strength was 0.2T.

[0098] Example 10

[0099] In Example 10, the method for increasing the vanadium content in converter vanadium slag includes:

[0100] S1. Vanadium-containing molten iron (of which, by mass, C is 4.4%, Si is 0.2%, Ti is 0.2%, P is 0.05%, V is 0.35%, and Cr is 0.2%) is smelted in a converter with oxygen blowing. During the smelting process, a dephosphorizing agent and a coolant are added to obtain molten vanadium slag and semi-steel. The vanadium-containing molten iron is 200t, the oxygen blowing temperature is 1290℃, the oxygen blowing time is 5 minutes, the dephosphorizing agent is 5t of Na2CO3, and the coolant is 10t of silicate.

[0101] S2. Add 0.01 t of Fe2O3@CeO2 core-shell structure with a particle size of 30 nm to the obtained molten vanadium slag; introduce CO2-O2 gas and stir; introduce ultrasound for the first 2 minutes after heating to the set temperature, then introduce microwaves, and finally apply a magnetic field for 2 minutes to obtain a mixture of magnetic solid vanadium spinel and molten liquid silicate; the ratio of CO2 to O2 in the CO2-O2 gas is 10:1, and the total flow rate is 50 m³ / min. 3 The reaction time was 5 minutes, and the temperature was set at 1350℃.

[0102] S3. A mixture of magnetic solid vanadium spinel and molten liquid silicate was separated under a magnetic field to obtain magnetic solid vanadium spinel and molten liquid silicate, respectively. The molten liquid silicate was poured out to obtain the solid Fe2VO4 phase. The magnetic field strength was 0.2T.

[0103] Comparative Example 1

[0104] In Comparative Example 1, the methods for treating vanadium slag include:

[0105] S1. Vanadium-containing molten iron is smelted in a converter by oxygen blowing. During the smelting process, dephosphorizing agent and coolant are added to obtain molten vanadium slag and semi-steel. Among them, the amount of vanadium-containing molten iron is 200t, the oxygen blowing smelting temperature is 1290℃, the oxygen blowing smelting time is 5 minutes, the amount of dephosphorizing agent Na2CO3 is 5t, and the amount of coolant silicate is 10t.

[0106] Comparative Example 2

[0107] In Comparative Example 2, the methods for treating vanadium slag include:

[0108] S1. Vanadium-containing molten iron is smelted in a converter by oxygen blowing. During the smelting process, dephosphorizing agent and coolant are added to obtain molten vanadium slag and semi-steel. Among them, the amount of vanadium-containing molten iron is 200t, the oxygen blowing smelting temperature is 1290℃, the oxygen blowing smelting time is 5 minutes, the amount of dephosphorizing agent CaO is 5t, and the amount of coolant silicate is 10t.

[0109] S2. CO2-O2 gas is introduced into the obtained molten vanadium slag and stirred. The mixture is heated to a set temperature to react, yielding a mixture of magnetic solid vanadium spinel and molten liquid silicate. The ratio of CO2 to O2 in the CO2-O2 gas is 10:1, and the total flow rate is 50 m³ / s. 3 The reaction time was 10 minutes, and the set temperature was 1350℃.

[0110] S3. A mixture of magnetic solid vanadium spinel and molten liquid silicate was separated under a magnetic field to obtain magnetic solid vanadium spinel and molten liquid silicate, respectively. The molten liquid silicate was poured out to obtain the solid Fe2VO4 phase. The magnetic field strength was 0.2T.

[0111] Table 1 lists the main components of the vanadium slag obtained in Examples 1-10 and Comparative Examples 1-2;

[0112] Table 1. List of main components of vanadium slag

[0113]

[0114]

[0115] As shown in Table 1, in the vanadium slags obtained in Examples 1-3, the contents of V₂O₃ and Cr₂O₃ in the spinel phase reached 27 wt.% and 11 wt.%, respectively, which are much higher than the contents of the vanadium slags in Comparative Examples 1-2. Meanwhile, the content of SiO₂ decreased, and the content of P was less than 0.003 wt.%. In Examples 4-8, the contents of V₂O₃ and Cr₂O₃ in the spinel phase reached 42 wt.%, which are much higher than the contents in Comparative Examples 1-2. 3、The content of SiO2 and P is zero; in Examples 9 and 10, the content of V2O3 and Cr2O3 can reach 50 wt.%, which is much higher than the content in Comparative Examples 1 and 2. The content of Cr2O3 can reach 12 wt.%, and the content of SiO2 and P is zero.

[0116] The method for increasing the vanadium content in converter vanadium slag disclosed in this invention involves initially separating vanadium spinel from the molten slag phase using a dephosphorizing agent. Then, the spinel is selectively oxidized to transform into magnetic vanadium spinel, which is further separated magnetically. The resulting vanadium spinel has a phosphorus content of less than 0.003 wt%. The magnetic vanadium spinel has a high vanadium content and a low phosphorus content. The silicate obtained from the reaction is added to the converter as a coolant, enabling iron recycling and significantly reducing the iron content in the tailings slag. Through vanadium extraction and dephosphorization, and magnetic separation, phosphorus remains in the silicate phase, while the enriched vanadium-iron spinel is phosphorus-free and can be directly used for vanadium extraction. The separated silicate phase is added to the vanadium extraction converter as a coolant to further recover iron and vanadium from the silicate, further reducing the iron and vanadium content in the tailings slag.

[0117] The technical solutions and technical details disclosed in the embodiments of this invention are merely illustrative of the inventive concept of this invention and do not constitute a limitation on the technical solutions of the embodiments of this invention. Any conventional changes, substitutions, or combinations made to the technical details disclosed in the embodiments of this invention have the same inventive concept as this invention and are within the protection scope of the claims of this invention.

Claims

1. A method for increasing the vanadium content in converter vanadium slag, characterized in that, Including the following steps: S1. Vanadium-containing molten iron is smelted in a converter using oxygen blowing. During the smelting process, a dephosphorizing agent and a coolant are added to obtain molten vanadium slag and semi-steel. The vanadium-containing molten iron contains the following components by mass: C 3.5–4.8 wt%, Si 0.01–0.36 wt%, Ti 0.01–0.32 wt%, P 0.01–0.1 wt%, V 0.05–0.5 wt%, and Cr 0–0.5 wt%. The semi-steel contains less than 0.003 wt% P. The molten vanadium slag contains more than 5 wt% CaO and more than 0.05 wt% P, with the remainder being Fe and unavoidable impurities. S2. Add materials containing high-valence oxides to the obtained molten vanadium slag, stir with CO2-O2 gas, and react at a set temperature; during the reaction, the reaction process is enhanced by ultrasound, microwave and magnetic field to obtain a mixture of magnetic solid vanadium spinel and molten liquid silicate; the content of the magnetic solid vanadium spinel is 20-100 wt%, excluding those with a content of 100 wt%; S3, a mixture of magnetic solid vanadium spinel and molten liquid silicate, is separated under a magnetic field to obtain magnetic solid vanadium spinel and molten liquid silicate, respectively.

2. The method for increasing the vanadium content in converter vanadium slag according to claim 1, characterized in that, It also includes the following steps: S4. The obtained molten liquid silicate is cooled and added to the converter as a coolant to realize the recycling of iron.

3. The method for increasing the vanadium content in converter vanadium slag according to claim 1, characterized in that, The dephosphorizing agent includes one or more of CaO, CaCO3, Na2CO3, MgO, Al2O3, and CaF2, and the coolant includes silicates.

4. The method for increasing the vanadium content in converter vanadium slag according to claim 1, characterized in that, In step S2, the temperature is set to 1000–1600℃, and the flow rate of CO2-O2 gas is 0–12 m³ / ton of vanadium slag. 3 And excluding materials with a flow rate of 0, including high-valence oxide materials such as MnO2, Mn2O3, Fe3O4, Fe2VO4, CeO2 or nanoscale core-shell structure Fe2O3@CeO2.

5. The method for increasing the vanadium content in converter vanadium slag according to claim 1, characterized in that, In step S3, the magnetic solid vanadium spinel and the molten liquid silicate mixture are separated at a temperature of 1000–1600 °C.

6. The method for increasing the vanadium content in converter vanadium slag according to claim 1, characterized in that, The amount of dephosphorizing agent added is 10-40 kg / ton of vanadium-containing molten iron, and the amount of coolant added is 10-70 kg / ton of vanadium-containing molten iron.

7. The method for increasing the vanadium content in converter vanadium slag according to claim 1, characterized in that, In step S2, ultrasonic heating is used in the initial mixing stage of the slag, with the ultrasonic intensity set to 20-40 kHz; microwave heating is used in the middle stage of the reaction, with the microwave frequency set to 2.45 GHz; and magnetic field heating is used in the later stage of the reaction, with the magnetic field intensity set to 0.1-0.5 T.

8. The method for increasing the vanadium content in converter vanadium slag according to claim 1, characterized in that, In step S3, the magnetic field strength is set between 0.1 and 0.5 T.

9. The method for increasing the vanadium content in converter vanadium slag according to claim 4, characterized in that, Materials containing high-valence oxides are combinations of MnO2 and Fe3O4, or combinations of Mn2O3 and Fe2VO4, or combinations of MnO2, Fe3O4, and CeO2, or MnO 2、 A combination of Fe2VO4 and CeO2, or a nanoscale core-shell structure Fe2O3@CeO2.

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