Vanadium titano-magnetite efficient reduction smelting method, reduction system and vanadium titano-magnetite smelting product

Abstract

The invention provides a vanadium titano-magnetite efficient reduction smelting method, a reduction system and a vanadium titano-magnetite smelting product, and relates to the field of vanadium titano-magnetite processing treatment.The vanadium titano-magnetite efficient reduction smelting method comprises the following steps that S1, multi-stage crushing and particle size regulation and control are conducted, specifically, vanadium titano-magnetite raw ore is subjected to three-stage crushing through a jaw crusher, a cone crusher and a high-pressure roller mill in sequence, the particle size range of the ore is controlled to be 0.1-3mm, and the particle size of-0.074 mm accounts for more than or equal to 80%. According to the device, the mineral dissociation degree and the valuable metal separation effect are effectively improved through the optimized multi-stage crushing technology and the combined separation technology, the pellet performance is enhanced in combination with the composite binder, the ore reduction activity is effectively improved, efficient enrichment and recovery of vanadium and titanium are achieved by precisely regulating and controlling the melt separation condition and the directional leaching technology, and the method is suitable for industrial production. And efficient recovery of iron, vanadium and titanium resources is achieved, valuable metal residues in tailings are greatly reduced, and the comprehensive utilization rate of the resources is increased.

Description

Technical Field

[0001] The present invention relates to the field of vanadium-titanium magnetite processing, in particular to a high-efficiency reduction smelting method and reduction system for vanadium-titanium magnetite and a vanadium-titanium magnetite smelting product. Background Art

[0002] Vanadium-titanium magnetite is a key source of strategic metals such as vanadium and titanium, and is widely used in aerospace, new energy batteries, and high-end alloy manufacturing. However, its mineral composition is complex, with iron, vanadium, and titanium often present in a symbiotic form. The titanium component, in particular, tends to form difficult-to-reduced minerals such as ilmenite (FeTiO3), severely hindering the efficiency of traditional blast furnace or electric furnace smelting.

[0003] Globally, the smelting of vanadium-titanium magnetite generally faces problems such as low resource utilization (vanadium recovery rate <70%, titanium recovery rate <60%), high energy consumption (comprehensive energy consumption >500kgce / t) and environmental pollution.

[0004] Although the current mainstream vanadium-titanium magnetite processing technology (such as rotary kiln pre-reduction-electric furnace smelting process) can partially improve the metal recovery rate, it still has major defects: low pretreatment efficiency: traditional crushing process is difficult to achieve full dissociation of minerals (dissociation degree <80%), and the recovery rate of magnetic separation-flotation for fine-grained ilmenite is less than 50%, resulting in a large amount of valuable metals remaining in the tailings (V+Ti+Fe>10wt%); high reduction energy consumption: relying on coke as the single reducing agent, the reaction activity is low, the energy consumption in the high-temperature section (>1400℃) accounts for more than 60%, and the carbon emission intensity is high; resource recovery is limited: the accuracy of smelting slag phase control is insufficient (alkalinity fluctuation>±0.3), vanadium and titanium are difficult to enrich in a targeted manner, and the titanium leaching rate of the acid leaching process for high perovskite slag is less than 70%. Summary of the Invention

[0005] The present invention aims to solve the shortcomings of the background technology, improve the efficiency of pretreatment in the process of vanadium-titanium magnetite treatment, reduce reduction energy consumption and improve resource recovery rate.

[0006] To achieve the above object, the present invention provides the following technical solution: a method for efficiently reducing and smelting vanadium-titanium magnetite, a reduction system, and a vanadium-titanium magnetite smelting product, comprising the following steps: Step S1: Multi-stage crushing and particle size control: The vanadium-titanium magnetite ore is sequentially crushed through a jaw crusher, a cone crusher, and a high-pressure roller mill, and the ore particle size is controlled to be in the range of 0.1-3 mm, of which the proportion of particles with a diameter of -0.074 mm is ≥80%; Step S2: Combined magnetic separation and flotation separation: The ore crushed in S1 is subjected to magnetic separation with a gradient magnetic field strength of 0.8-1.5T to separate the iron-vanadium concentrate (TFe ≥ 58%, TiO2 ≥ 12%). Subsequently, the non-magnetic minerals are subjected to a flotation process using sodium oleate and sodium dodecyl sulfate in a mass ratio of 2:1 as collectors (dosage of 200-400g / t ore) to recover the titanium concentrate (TiO2 ≥ 46%). Step S3: Composite binder agglomeration: the iron-vanadium concentrate obtained in S2 is mixed with a composite binder to form agglomerates, wherein the composite binder is composed of sodium silicate (3-5wt%), lignin sulfonate (1-2wt%) and the balance water, and the pellet compressive strength after agglomeration is ≥2500N / piece and the reduction expansion ratio is ≤15%; Step S4: Microwave and gas synergistic reduction: The pellets are mixed with a composite reducing agent in a mass ratio of 10:2-10:3, wherein the composite reducing agent consists of blue charcoal (60-70 wt%), biochar (20-30 wt%), and CaF2 (3-5 wt%), with a particle size of ≤1 mm; the mixture is preheated to 800-1000°C in a microwave preheating section (frequency 2.45 GHz, power density 5-10 W / cm³), and then enters a gas temperature control section (natural gas and oxygen mixed combustion, oxygen concentration 25-35 vol%), and is reduced at 1200-1350°C for 1-3 hours; Step S5: Melting and Resource Recovery: The reduction product is melted at 1450-1550°C, and the slag phase basicity (CaO / SiO2) is controlled to 0.8-1.2 to obtain molten iron with a metallization rate ≥90% and titanium-rich slag (TiO2 ≥35wt%); the molten iron is blown to extract vanadium (recovery rate ≥88%), and the titanium-rich slag is leached with sulfuric acid (concentration 40-60wt%, temperature 90-110°C) to recover titanium (leaching rate ≥85%).

[0007] Furthermore, the step S1 also includes: the rolling pressure of the high pressure roller grinding mill is 4-6 MPa, and the mineral dissociation degree of the crushed ore is ≥95%.

[0008] Furthermore, the step S2 further includes: controlling the pH value of the flotation process to be 6.5-7.5, and the flotation time to be 10-15 minutes.

[0009] Furthermore, the step S3 also includes: the agglomeration process adopts a disc pelletizing machine with a rotation speed of 15-25 rpm, a pellet size of 10-15 mm, a curing condition of a temperature of 20-25° C., a humidity of 70-80%, and a curing period of ≥48 h.

[0010] Furthermore, the step S4 also includes: the microwave preheating section and the gas temperature control section are connected by a high-temperature resistant ceramic conveyor belt, the conveyor belt speed is 0.1-0.5m / min, and the gas section temperature fluctuation range is ≤±20°C.

[0011] Furthermore, the step S5 also includes: the liquid-to-solid ratio of the sulfuric acid leaching is 4:1-6:1, the leaching time is 2-4 hours, and the residual TiO2 in the leached residue is ≤5%.

[0012] Furthermore, the step S5 further comprises: the tail liquid after acid leaching of the titanium-rich slag is neutralized and then recycled for flotation process, and the heavy metal ion concentration in the tail liquid is ≤0.1 mg / L.

[0013] A composite reducing agent, specifically used for any method of claims 1-6, wherein the biomass charcoal is straw charcoal or sawdust charcoal, has a specific surface area of ​​≥300m² / g, and CaF2 is uniformly dispersed in the pores of the reducing agent in the form of nanoparticles.

[0014] A microwave and gas coordinated reduction system for implementing any method of claims 1-6, comprising: a microwave cavity, wherein the frequency in the microwave cavity is at least 2.45 GHz and the power is adjustable in the range of 5-20 kW; a gas heating section, wherein the gas heating section is equipped with a multi-stage burner and an infrared temperature measurement feedback device; and a sealed material conveying device, wherein the sealed material conveying device adopts a high-temperature resistant ceramic conveyor belt with a temperature resistance of ≥1500°C.

[0015] A vanadium-titanium magnetite smelting product, prepared by any method of claims 1-9: the vanadium content in the molten iron is ≥0.3wt%, and the sulfur content is ≤0.03wt%; the TiO2 crystalline phase in the titanium-rich slag is a perovskite-type structure, and the acid leaching activity is ≥90%; the total residual V+Ti+Fe in the tailings is ≤3wt%, and can be directly used for the preparation of roadbed materials.

[0016] The present invention provides a high-efficiency reduction smelting method for vanadium-titanium magnetite, a reduction system, and a vanadium-titanium magnetite smelting product, which have the following beneficial effects: The advantages of the present invention are that, through the optimized multi-stage crushing process and combined sorting technology, the present invention effectively improves the mineral dissociation degree and the valuable metal separation effect, combines the composite binder to strengthen the pellet performance, effectively improves the ore reduction activity, and achieves efficient enrichment and recovery of vanadium and titanium through precise control of melting conditions and directional leaching process, realizes efficient recovery of iron, vanadium and titanium resources, greatly reduces the valuable metal residues in the tailings, and improves the comprehensive utilization rate of resources. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 The figure is a flow chart of the efficient processing and reduction smelting process of vanadium-titanium magnetite of the present invention.

[0018] Figure 2 It is a schematic structural diagram of the microwave and gas coordinated reduction system of the present invention.

[0019] Figure 3This is a SEM schematic diagram of the microstructure of the composite reducing agent of the present invention.

[0020] Figure 4 This is a statistical diagram of an experiment performed in accordance with an embodiment of the present invention. DETAILED DESCRIPTION

[0021] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the embodiments described are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without making creative efforts are within the scope of protection of this application.

[0022] The disclosure below provides many different embodiments or examples for realizing the different structures of the present application. In order to simplify the disclosure of the present application, the components and settings of specific examples are described below. Of course, they are merely examples and are not intended to limit the present application. In addition, the present application may repeat reference numbers and / or reference letters in different examples, and such repetition is for the purpose of simplicity and clarity, and does not itself indicate the relationship between the various embodiments and / or settings discussed. In addition, the present application provides examples of various specific processes and materials, but those of ordinary skill in the art will appreciate the application of other processes and / or the use of other materials.

[0023] The embodiments of the present application provide a method for the efficient reduction and smelting of vanadium-titanium magnetite, a reduction system and a vanadium-titanium magnetite smelting product. The method, the reduction system and the vanadium-titanium magnetite smelting product can be realized through an optimized multi-stage crushing process and a combined sorting technology, effectively improving the degree of mineral dissociation and the separation effect of valuable metals, combining a composite binder to strengthen the pellet performance, effectively improving the ore reduction activity, and through precise control of the melting conditions and the directional leaching process, achieving efficient enrichment and recovery of vanadium and titanium, achieving efficient recovery of iron, vanadium and titanium resources, significantly reducing the residual valuable metals in the tailings, and improving the comprehensive utilization rate of resources. The following describes in detail the method for the efficient reduction and smelting of vanadium-titanium magnetite, the reduction system and the vanadium-titanium magnetite smelting product. It should be noted that the description order of the following embodiments is not intended to limit the preferred order of the embodiments.

[0024] The present application is described in detail below with reference to the accompanying drawings and specific implementation methods.

[0025] A high-efficiency reduction smelting method for vanadium-titanium magnetite, a reduction system, and a vanadium-titanium magnetite smelting product, comprising the following steps: Step S1: Multi-stage crushing and particle size control: The vanadium-titanium magnetite ore is sequentially crushed through a jaw crusher, a cone crusher, and a high-pressure roller mill, and the ore particle size is controlled to be in the range of 0.1-3 mm, of which the proportion of particles with a diameter of -0.074 mm is ≥80%; Step S2: Combined magnetic separation and flotation separation: The ore crushed in S1 is subjected to magnetic separation with a gradient magnetic field strength of 0.8-1.5T to separate the iron-vanadium concentrate (TFe ≥ 58%, TiO2 ≥ 12%). Subsequently, the non-magnetic minerals are subjected to a flotation process using sodium oleate and sodium dodecyl sulfate in a mass ratio of 2:1 as collectors (dosage of 200-400g / t ore) to recover the titanium concentrate (TiO2 ≥ 46%). Step S3: Composite binder agglomeration: the iron-vanadium concentrate obtained in S2 is mixed with a composite binder to form agglomerates, wherein the composite binder is composed of sodium silicate (3-5wt%), lignin sulfonate (1-2wt%) and the balance water, and the pellet compressive strength after agglomeration is ≥2500N / piece and the reduction expansion ratio is ≤15%; Step S4: Microwave and gas synergistic reduction: The pellets are mixed with a composite reducing agent in a mass ratio of 10:2-10:3, wherein the composite reducing agent consists of blue charcoal (60-70 wt%), biochar (20-30 wt%), and CaF2 (3-5 wt%), with a particle size of ≤1 mm; the mixture is preheated to 800-1000°C in a microwave preheating section (frequency 2.45 GHz, power density 5-10 W / cm³), and then enters a gas temperature control section (natural gas and oxygen mixed combustion, oxygen concentration 25-35 vol%), and is reduced at 1200-1350°C for 1-3 hours; Step S5: Melting and Resource Recovery: The reduction product is melted at 1450-1550°C, and the slag phase basicity (CaO / SiO2) is controlled to 0.8-1.2 to obtain molten iron with a metallization rate ≥90% and titanium-rich slag (TiO2 ≥35wt%); the molten iron is blown to extract vanadium (recovery rate ≥88%), and the titanium-rich slag is leached with sulfuric acid (concentration 40-60wt%, temperature 90-110°C) to recover titanium (leaching rate ≥85%).

[0026] Furthermore, the step S1 also includes: the rolling pressure of the high pressure roller grinding mill is 4-6 MPa, and the mineral dissociation degree of the crushed ore is ≥95%.

[0027] Furthermore, the step S2 further includes: controlling the pH value of the flotation process to be 6.5-7.5, and the flotation time to be 10-15 minutes.

[0028] Furthermore, the step S3 also includes: the agglomeration process adopts a disc pelletizing machine with a rotation speed of 15-25 rpm, a pellet size of 10-15 mm, a curing condition of a temperature of 20-25° C., a humidity of 70-80%, and a curing period of ≥48 h.

[0029] Furthermore, the step S4 also includes: the microwave preheating section and the gas temperature control section are connected by a high-temperature resistant ceramic conveyor belt, the conveyor belt speed is 0.1-0.5m / min, and the gas section temperature fluctuation range is ≤±20°C.

[0030] Furthermore, the step S5 also includes: the liquid-to-solid ratio of the sulfuric acid leaching is 4:1-6:1, the leaching time is 2-4 hours, and the residual TiO2 in the leached residue is ≤5%.

[0031] Furthermore, the step S5 further comprises: the tail liquid after acid leaching of the titanium-rich slag is neutralized and then recycled for flotation process, and the heavy metal ion concentration in the tail liquid is ≤0.1 mg / L.

[0032] A composite reducing agent, specifically used for any method of claims 1-6, wherein the biomass charcoal is straw charcoal or sawdust charcoal, has a specific surface area of ​​≥300m² / g, and CaF2 is uniformly dispersed in the pores of the reducing agent in the form of nanoparticles.

[0033] A microwave and gas coordinated reduction system for implementing any method of claims 1-6, comprising: a microwave cavity, wherein the frequency in the microwave cavity is at least 2.45 GHz and the power is adjustable in the range of 5-20 kW; a gas heating section, wherein the gas heating section is equipped with a multi-stage burner and an infrared temperature measurement feedback device; and a sealed material conveying device, wherein the sealed material conveying device adopts a high-temperature resistant ceramic conveyor belt with a temperature resistance of ≥1500°C.

[0034] A vanadium-titanium magnetite smelting product, prepared by any method of claims 1-9: the vanadium content in the molten iron is ≥0.3wt%, and the sulfur content is ≤0.03wt%; the TiO2 crystalline phase in the titanium-rich slag is a perovskite-type structure, and the acid leaching activity is ≥90%; the total residual V+Ti+Fe in the tailings is ≤3wt%, and can be directly used for the preparation of roadbed materials.

[0035] The following describes specific embodiments based on the above technical foundation.

[0036] Example 1

[0037] A specific implementation provided in this embodiment includes: Step S1: Multi-stage crushing and particle size control: Vanadium-titanium magnetite ore (TFe 45%, TiO2 10%) is taken and crushed in three stages, namely, a jaw crusher (discharge particle size ≤ 50 mm), a cone crusher (discharge particle size ≤ 10 mm), and a high-pressure roller mill (rolling pressure 5 MPa). The final ore particle size range is 0.1-3 mm, of which -0.074 mm particles account for 85%, and the mineral dissociation degree test result is 96%.

[0038] Step S2: Combined magnetic separation and flotation separation: The crushed ore was subjected to magnetic separation with a gradient magnetic field strength of 1.2 T to obtain iron-vanadium concentrate (TFe 62%, TiO2 13%). Non-magnetic minerals were separated by flotation process. The collectors were sodium oleate and sodium dodecyl sulfate (mass ratio 2:1, dosage 300 g / t ore). The flotation pH value was 7.0 and the flotation time was 12 minutes. Titanium concentrate (TiO2 46%) was recovered.

[0039] Step S3: Agglomeration with a composite binder: The iron-vanadium concentrate is mixed with a composite binder (sodium silicate 4wt%, lignin sulfonate 1.5wt%) and pelletized in a disc pelletizer (rotating speed 20rpm). The pellets have a particle size of 12-15mm. The pellets are cured at a temperature of 22°C and a humidity of 75% for 72 hours. The compressive strength reaches 2600N / piece and the reduction expansion rate is 14%.

[0040] Step S4: Microwave and gas synergistic reduction: The pellets were mixed with a composite reducing agent (65% semi-coke, 25% biochar, and 25% CaF, with a particle size of ≤1 mm) in a mass ratio of 10:3. The mixture was preheated to 900°C in a microwave preheating section (frequency 2.45 GHz, power density 8 W / cm³), and the gas temperature control section (natural gas mixed with oxygen, oxygen concentration 30 vol%) was controlled to 1300°C. The reduction time was 2 hours. The speed of the high-temperature resistant ceramic conveyor belt was 0.3 m / min, and the temperature fluctuation in the gas section was ±15°C.

[0041] Step S5: Melting and Resource Recovery: The reduction product is melted at 1500°C, and the slag phase alkalinity (CaO / SiO2) is controlled at 1.0 to obtain molten iron with a metallization rate of 92% (vanadium content 0.35%) and titanium-rich slag (TiO2 38%). The molten iron is blown to extract vanadium (recovery rate 89%); the titanium-rich slag is leached with sulfuric acid (concentration 50wt%, temperature 100°C, liquid-solid ratio 5:1) for 3 hours, with a titanium leaching rate of 86% and a TiO2 residual content of 4.5% in the leached slag. The acid leaching tail liquid is neutralized (pH 7.0) to a heavy metal ion concentration of ≤0.08mg / L, and is recycled for flotation process.

[0042] Product characteristics: sulfur content in molten iron is 0.02wt%; XRD of titanium-rich slag shows perovskite structure, acid leaching activity is 91%; the total residual V+Ti+Fe in the tailings is 2.8wt%, which can meet the compressive strength standards of roadbed materials.

[0043] Example 2

[0044] A specific implementation provided in this embodiment includes: Step S1: Multi-stage crushing and particle size control: After the raw ore is crushed by a jaw crusher, a cone crusher, and a high-pressure roller mill (rolling pressure 4 MPa), the ore particle size is 0.1-3 mm, with particles of -0.074 mm accounting for 82%, and the mineral dissociation degree is 94%.

[0045] Step S2: combined magnetic separation and flotation separation: magnetic field strength 0.8 T, iron-vanadium concentrate (TFe 58%, TiO2 12%), flotation pH 6.5, collector dosage 200 g / t ore, flotation time 10 minutes, titanium concentrate (TiO2 45%).

[0046] Step S3: Composite binder briquetting: composite binder (sodium silicate 3wt%, lignin sulfonate 1wt%), pellet size 10-12mm, curing temperature 20°C, humidity 70%, curing for 48 hours, compressive strength 2500N / piece.

[0047] Step S4: Microwave and gas synergistic reduction: composite reducing agent (60% blue charcoal, 30% biochar, 3% CaF2), microwave preheating at 800°C, gas stage reduction at 1200°C for 1 hour, conveyor belt speed 0.1m / min, temperature fluctuation ±10°C.

[0048] Step S5: melting and resource recovery: melting temperature 1450°C, slag phase basicity 0.8, molten iron metallization rate 90%, titanium-rich slag TiO2 35%, sulfuric acid concentration 40wt%, leaching temperature 90°C, titanium leaching rate 85%.

[0049] Product characteristics: molten iron sulfur content 0.03wt%; tailings V+Ti+Fe residual content 3.0wt%.

[0050] Example 3

[0051] A specific implementation provided in this embodiment includes: Step S1: multi-stage crushing and particle size control: the high pressure roller mill has a roller pressure of 6 MPa, the -0.074 mm particle size accounts for 88%, and the mineral dissociation degree is 97%.

[0052] Step S2: combined magnetic separation and flotation separation: magnetic separation field strength 1.5T, iron-vanadium concentrate (TFe 65%, TiO2 14%), flotation pH 7.5, collector dosage 400g / t ore, flotation time 15 minutes, titanium concentrate (TiO2 48%).

[0053] Step S3: Composite binder briquetting: composite binder (5 wt% sodium silicate, 2 wt% lignin sulfonate), pellet size 15 mm, curing temperature 25°C, humidity 80%, compressive strength 2700 N / piece.

[0054] Step S4: Microwave and gas synergistic reduction: composite reducing agent (semi-carbon 70%, biochar 20%, CaF2 5%), microwave preheating at 1000°C, gas stage reduction at 1350°C for 3 hours, conveyor speed 0.5 m / min, temperature fluctuation ±20°C.

[0055] Step S5: melting and resource recovery: melting temperature 1550°C, slag phase basicity 1.2, molten iron metallization rate 94%, titanium-rich slag TiO2 40%, sulfuric acid concentration 60wt%, leaching temperature 110°C, titanium leaching rate 88%.

[0056] Product characteristics: molten iron sulfur content is 0.01wt%; acid leaching tailings heavy metal concentration is 0.05mg / L; tailings are directly used as roadbed materials, and the compressive strength exceeds the standard by 20%.

[0057] For the above three specific embodiments, a comparison table (attached Figure 3 )get: Reduction rate and metallization rate: The reduction rates of the three examples were all ≥90% (up to 94%), and the molten iron metallization rate was ≥90%, verifying the effectiveness of multi-stage crushing (mineral dissociation degree ≥95%) and composite binder agglomeration (compressive strength ≥2500N / piece), indicating that the pretreatment process significantly improved the reduction activity of the ore.

[0058] Vanadium and titanium recovery rates: Vanadium recovery rate ≥ 85% (maximum 91%), titanium leaching rate ≥ 85% (maximum 88%), indicating that slag phase control (alkalinity 0.8-1.2) and sulfuric acid leaching optimization (liquid-solid ratio 4:1-6:1) can enrich valuable metals in a targeted manner and significantly reduce resource waste.

[0059] Energy consumption comparison: The comprehensive energy consumption of Examples 1-3 is 20-25% lower than that of the traditional process, mainly due to the microwave and gas synergistic heating technology (microwave preheating shortens the reduction time, and gas temperature control optimizes thermal efficiency).

[0060] Environmental protection indicators: The heavy metal concentration of the acid leaching tail liquid is ≤0.1 mg / L (0.08 mg / L in Example 1), and the tail liquid is recycled for the flotation process, which meets the requirements of green smelting.

[0061] Impact of parameter fluctuations: Even within the fluctuation range of parameters such as high-pressure roller grinding pressure (4-6MPa), flotation pH (6.5-7.5), and microwave power (5-10W / cm³), key indicators (such as reduction rate and titanium leaching rate) remain stable, indicating that the technical solution has strong industrial adaptability.

[0062] Product quality consistency: molten iron sulfur content ≤ 0.03wt%, titanium-rich slag acid leaching activity ≥ 90%, indicating precise process control and reliable product performance.

[0063] This technical solution achieves the following through an integrated design of efficient pretreatment, composite reduction and directional recovery: First, efficient extraction of vanadium and titanium resources (recovery rate ≥ 85%, tailings utilization rate ≥ 97%); Second, reduce both energy consumption and carbon emissions (comprehensive energy consumption ≤ 380kgce / t, biochar replacement rate 20-30%); Third, synergy between environmental protection and economic benefits (tailings recycling, tailings resource utilization, and reduction of heavy metal emissions).

[0064] In the above embodiments, the description of each embodiment has its own focus. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0065] The above is a detailed introduction to the efficient reduction and smelting method of vanadium-titanium magnetite, the reduction system and the vanadium-titanium magnetite smelting product provided in the embodiments of the present application. Specific examples are used in this article to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the technical solution and core idea of ​​the present application; ordinary technicians in this field should understand that they can still modify the technical solutions recorded in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein; and these modifications or replacements do not cause the essence of the corresponding technical solution to deviate from the scope of the technical solution of the embodiments of the present application.

Claims

1. A method for efficient reduction and smelting of vanadium-titanium magnetite, characterized in that: The following steps are involved: Step S1: Multi-stage crushing and particle size control: The vanadium-titanium magnetite ore is sequentially crushed through a jaw crusher, a cone crusher, and a high-pressure roller mill, and the ore particle size is controlled to be in the range of 0.1-3 mm, of which the proportion of particles with a diameter of -0.074 mm is ≥80%; Step S2: Combined magnetic separation and flotation separation: The ore crushed in S1 is subjected to magnetic separation with a gradient magnetic field strength of 0.8-1.5T to separate the iron-vanadium concentrate (TFe ≥ 58%, TiO2 ≥ 12%). Subsequently, the non-magnetic minerals are subjected to a flotation process using sodium oleate and sodium dodecyl sulfate in a mass ratio of 2:1 as collectors (dosage of 200-400g / t ore) to recover the titanium concentrate (TiO2 ≥ 46%). Step S3: Composite binder agglomeration: the iron-vanadium concentrate obtained in S2 is mixed with a composite binder to form agglomerates, wherein the composite binder is composed of sodium silicate (3-5wt%), lignin sulfonate (1-2wt%) and the balance water, and the pellet compressive strength after agglomeration is ≥2500N / piece and the reduction expansion ratio is ≤15%; Step S4: Microwave and gas synergistic reduction: The pellets are mixed with a composite reducing agent in a mass ratio of 10:2-10:3, wherein the composite reducing agent consists of blue charcoal (60-70 wt%), biochar (20-30 wt%), and CaF2 (3-5 wt%), with a particle size of ≤1 mm; the mixture is preheated to 800-1000°C in a microwave preheating section (frequency 2.45 GHz, power density 5-10 W / cm³), and then enters a gas temperature control section (natural gas and oxygen mixed combustion, oxygen concentration 25-35 vol%), and is reduced at 1200-1350°C for 1-3 hours; Step S5: Melting and Resource Recovery: The reduction product is melted at 1450-1550°C, and the slag phase basicity (CaO / SiO2) is controlled to 0.8-1.2 to obtain molten iron with a metallization rate ≥90% and titanium-rich slag (TiO2 ≥35wt%); the molten iron is blown to extract vanadium (recovery rate ≥88%), and the titanium-rich slag is leached with sulfuric acid (concentration 40-60wt%, temperature 90-110°C) to recover titanium (leaching rate ≥85%).

2. The high-efficiency reduction smelting method of vanadium-titanium magnetite according to claim 1, characterized in that: The step S1 further includes: the roller pressure of the high pressure roller grinding mill is 4-6 MPa, and the mineral dissociation degree of the crushed ore is ≥95%.

3. The high-efficiency reduction smelting method of vanadium-titanium magnetite according to claim 1, characterized in that: The step S2 further includes: controlling the pH value of the flotation process to be 6.5-7.5, and the flotation time to be 10-15 minutes.

4. The high-efficiency reduction smelting method of vanadium-titanium magnetite according to claim 1, characterized in that: The step S3 also includes: the agglomeration process adopts a disc pelletizing machine with a rotation speed of 15-25 rpm, a pellet size of 10-15 mm, a curing condition of a temperature of 20-25° C., a humidity of 70-80%, and a curing period of ≥48 h.

5. The high-efficiency reduction smelting method of vanadium-titanium magnetite according to claim 1, characterized in that: The step S4 also includes: connecting the microwave preheating section and the gas temperature control section through a high-temperature resistant ceramic conveyor belt, the conveyor belt speed is 0.1-0.5m / min, and the gas section temperature fluctuation range is ≤±20°C.

6. The high-efficiency reduction smelting method of vanadium-titanium magnetite according to claim 1, characterized in that: The step S5 further includes: the liquid-to-solid ratio of the sulfuric acid leaching is 4:1-6:1, the leaching time is 2-4 hours, and the residual TiO2 in the leached residue is ≤5%.

7. The high-efficiency reduction smelting method of vanadium-titanium magnetite according to claim 1, characterized in that: The step S5 further includes: the tail liquid after acid leaching of the titanium-rich slag is neutralized and then circulated for flotation process, and the heavy metal ion concentration in the tail liquid is ≤0.1 mg / L.

8. A composite reducing agent, specifically used in any method of claims 1-6, characterized in that: The biomass charcoal is straw charcoal or sawdust charcoal with a specific surface area of ​​≥300m² / g, and CaF2 is uniformly dispersed in the pores of the reducing agent in the form of nanoparticles.

9. A microwave and gas synergistic reduction system for implementing any of the methods of claims 1 to 6, characterized in that: include: A microwave cavity having an internal frequency of at least 2.45 GHz and an adjustable power range of 5-20 kW; A gas heating section equipped with a multi-stage burner and an infrared temperature measurement feedback device; A sealed material conveying device adopts a high-temperature resistant ceramic conveyor belt with a temperature resistance of ≥1500°C.

10. A vanadium-titanium magnetite smelting product prepared by the method according to any one of claims 1 to 9, characterized in that: The vanadium content in the molten iron is ≥0.3wt%, and the sulfur content is ≤0.03wt%; The TiO2 crystalline phase in the titanium-rich slag is a perovskite structure, and the acid leaching activity is ≥90%; The total residual content of V+Ti+Fe in the tailings is ≤3wt%, and can be directly used in the preparation of roadbed materials.

Images