A system and method for simultaneously producing low-carbon pure iron, vanadyl sulfate, titanium dioxide, and high-end titanium sponge from vanadium titano-magnetite

Abstract

The present application belongs to the field of energy and metallurgy. Specifically, the present application discloses a system and method for simultaneously producing low-carbon pure iron, vanadyl sulfate, titanium dioxide and high-end titanium sponge from vanadium-titanium-iron ore. The vanadium-titanium-iron ore is directly acid-dissolved by an acid-dissolution separation process to separate vanadyl sulfate, titanyl sulfate and iron salt crystals. The titanyl sulfate is used to produce sulfuric acid titanium dioxide through fine particle hydrolysis. The titanyl sulfate is used to prepare high-end titanium sponge through coarse particle hydrolysis, fluidized calcination, fluidized chlorination and magnesium hot reduction. The iron salt is purified through a dissolution purification process to obtain an iron salt solution, a dissolution residue and a purification residue. The dissolution residue and the purification residue are recycled and the sulfur is recycled through high-temperature desulfurization. The pure iron is prepared through valence adjustment and battery iron smelting, the sulfuric acid is recycled, and hydrogen and oxygen are recycled. The solar furnace is used to provide heat for the high-temperature desulfurization and acid-dissolution processes, and the energy is low-carbonized. The present application is suitable for large-scale and continuous treatment of vanadium-titanium-iron ore, and has the advantages of high efficiency, low energy consumption, no pollution and good economic efficiency.

Description

Technical Field

[0001] This invention belongs to the fields of energy and metallurgy, and specifically relates to a system and method for simultaneously producing low-carbon pure iron, vanadium oxysulfate, titanium dioxide and high-end sponge titanium from vanadium-titanium iron ore. Background Technology

[0002] In 2021, my country's crude steel production was approximately 1 billion tons, emitting about 1.8 billion tons of CO2, accounting for about 16% of the country's total emissions. my country's steel industry primarily utilizes a long process, such as blast furnace-converter, accounting for as much as 90% of production. Blast furnace ironmaking is the main source of CO2 emissions, accounting for about 70% of the entire process. Blast furnace ironmaking uses coke as a reducing agent to remove oxygen from iron ore, producing molten iron, but releasing large amounts of CO2. Against the backdrop of "carbon peaking" and "carbon neutrality," the steel industry urgently needs to develop transformative low-carbon ironmaking technologies.

[0003] Currently developed ultra-low carbon ironmaking technologies mainly focus on replacing coke. These include hydrogen reduction as a substitute for carbon reduction and electroreduction as a substitute for carbon reduction.

[0004] The "hydrogen reduction" route, namely, hydrogen production through water electrolysis and hydrogen reduction of iron, is described in patent CN112159880B. This method and apparatus for hydrogen iron smelting involves using microwave irradiation to smelt iron ore in a hydrogen or hydrogen-rich gas atmosphere to obtain directly reduced iron. This solves the problem of significant carbon dioxide emissions still occurring when using hydrogen-rich gas to reduce iron oxides in existing hydrogen iron smelting processes. Patent application CN102586527A discloses a new hydrogen-carbon molten reduction iron smelting process. The heat required for the entire process is provided by the combustion of oxygen-coal and the secondary combustion of reducing gases. Compared with existing processes, this process reduces CO2 emissions by approximately 10%. Patent application CN105886688A discloses a green circular production system where hydrogen replaces carbon in reducing iron ore to elemental iron during metal smelting. No CO2 is produced in the process; the steam generated during smelting generates electricity, and the H2 produced from water electrolysis is recycled. However, current industrial-scale water electrolysis for hydrogen production primarily uses alkaline aqueous solutions, with an energy efficiency of around 60%, and the efficiency of hydrogen production is also relatively low. In the process of hydrogen reducing iron, due to limited thermodynamic equilibrium, the single-cycle conversion rate is low, requiring multiple cycles and increasing energy consumption. Simultaneously, the thermal effect of hydrogen reducing iron is poor, requiring a significant amount of additional thermal energy. Overall, "hydrogen metallurgy" essentially consumes green electrical energy; it is electrometallurgy. Developing a step-by-step electrochemical reduction of iron is also of great significance.

[0005] Iron ore can be decomposed into metallic iron and release oxygen under electrochemical action. This process is generally carried out in three typical systems: a high-temperature molten salt / molten iron oxide system, an alkaline system, and an acidic system. The high-temperature molten salt / molten iron oxide system is described in patent application CN114232033A, which discloses a method for preparing high-purity iron by high-temperature molten salt electroreduction using CaCl2. Fe2O3 In a CaO molten salt system, high-purity iron (99.94%) can be obtained through molten salt electroreduction at a certain current density and an inert argon atmosphere at 850℃. Patent CN101906646B discloses a method for producing metallic iron from iron ore via molten salt electrolysis, using a Fe2O3-Al2O3-SiO2 molten salt system, and obtaining metallic iron through molten salt electroreduction at a certain current density and electrolysis temperature (1580-1620℃). Patent CN109477232B discloses a method for preparing iron by reducing molten oxides using electrolytic deposition, using a Na2O2-B2O3-Fe2O3 molten salt system, and obtaining metallic iron (97%) through molten salt electroreduction at a certain voltage (1.5V / 2.5V) and electrolysis temperature (1000℃). Currently, the main challenges of high-temperature molten salt / molten iron oxide systems are the development of economical inert anode materials, suitable electrolyte systems, and the purification of raw materials.

[0006] An alkaline solution electroreduction technique for producing iron. Allanore A et al. (DOI: 10.1149 / 1.2790285) experimentally demonstrated that electrolysis of suspended iron oxide particles in a sodium hydroxide solution (50% mass concentration, 110℃) (iron ion concentration 2.6 × 10⁻⁶) yields iron. -3The invention mentions the possibility of iron formation (M), but also notes the very low solubility of hematite in this system, leading to extremely low reduction efficiency. Patent CN101696510B discloses a method and apparatus for preparing high-purity iron powder through electrolytic deoxygenation, involving an electrochemical method for obtaining high-purity iron from solid iron oxide. Solid iron oxide is a sintered body or ore composed of single or mixed Fe2O3, Fe3O4, and FeO. The anode and cathode are located at opposite ends of an electrolytic cell. The electrolytic cell contains an ion-conducting membrane and a high-temperature hydroxide solution (sodium hydroxide or potassium hydroxide, at 700-800℃). A preset voltage is applied between the electrodes to drive oxygen ions to diffuse from the iron oxide in the cathode basket to the anode, where high-purity iron can be obtained. However, in this patent, the anode must be a solid material with strong alkali resistance, corrosion resistance, and good conductivity, and the solid oxygen ion-conducting membrane must also possess alkali resistance and corrosion resistance, thus resulting in high costs. In addition, to prevent impurities in solid iron oxide from dissolving in high-temperature alkaline solutions and adversely affecting electrolyte performance, iron oxide needs to undergo impurity removal pretreatment, which will lead to a significant increase in economic and environmental costs.

[0007] Acidic Solution Electroreduction Technology for Iron Production. Researchers have conducted extensive work on the electroreduction of iron from acidic iron-containing solutions, primarily aiming to prepare high-purity metallic iron and pure iron powder. The most common electrolyte solutions used in this process are ferrous chloride and ferrous sulfate. Acidic FeCl2 solution: Patent application CN107955952A discloses a method for producing high-purity iron powder from iron slag. This involves leaching (leaching solution composition: 15-19 parts sodium hydroxide, 5-9 parts sodium methacrylate, 260-300 parts water) to remove inorganic components such as silica from the iron slag, increasing the iron particle content in the filter residue. An electrolyte solution containing 6-9 parts (15% by volume) of hydrochloric acid, 10-14 parts (magnesium sulfate), and 900-1000 parts (water) is then added for electrolysis. Finally, the surface of the iron powder is cleaned using an 18-22% (w / w) ethylenediaminetetraacetic acid solution to obtain high-purity iron powder. The patented method consumes large amounts of sodium hydroxide and hydrochloric acid during leaching and electrolysis. Furthermore, due to impurities and concentration, these leachates and electrolytes cannot be recycled, making subsequent processing difficult. Patent CN101517129B discloses an electrochemical method for recovering iron and chlorine from an iron-rich metal chloride solution, with a cathode electrolyte pH of 0.9-1.1, an electroreduction temperature of 80-85℃, and a cathode current density of 200-500 A / m. 2 The current efficiency is 96.4%-97.9%, and the purity of iron prepared by electroreduction is 99.99%. This patent has high requirements for the control of impurity content and pH in the solution. The ferric chloride solution needs to be adjusted to a relatively low pH value to prevent the pH value on the cathode surface from rising to a level higher than the precipitation pH value of other impurities, causing co-precipitation. However, it cannot be too low to prevent the release of hydrogen gas as a byproduct.

[0008] Acidic FeSO4 electrolyte solution. Patent application CN113481540A discloses a method for preparing high-purity iron, using a soluble anode, an electrolyte mainly containing FeSO4 and a small amount of stabilizer, and a cathode current density of 100. 230A / m 2 The electrolyte pH is 1.00-4.00, the electrolyte temperature is 20-100℃, the purity of the iron prepared by electrolysis is 99.90%-99.99%, and the deposition thickness is 20μm-3cm. This patent uses a sulfuric acid system, and the soluble anode is industrial pure iron, low carbon steel, etc., so the purity of the electrolyte solution is high. However, if the purity of the electrolyte decreases, it will lead to a series of problems such as the occurrence of more side reactions, reduced current efficiency, and contamination by impurities. Patent CN102084034B discloses an electrochemical method for recovering metallic iron or iron-rich alloys, oxygen, and sulfuric acid from iron-rich metal sulfate waste (byproduct of the ilmenite sulfate process). The electrolyte is an iron-rich metal sulfate solution, the electrolyte pH is 1.4-3.5, the electrolyte temperature is 25-60℃, and the cathode current density used is 300. 1000A / m 2 The purity of iron produced by electrolysis can reach 99.99%, with a current efficiency of 95%-98%. In this patent, the iron-rich metal sulfate solution must undergo pretreatment (such as pH adjustment) before electroreduction, and the acidic insoluble solids produced in this process are also difficult to handle. Furthermore, E. Mostad et al. (DOI:10.1016 / j.hydromet.2007.07.014) mentioned that a Norwegian smelter conducted a semi-industrial electroreduction experiment between 1947 and 1957 using pyrite (FeS2) as raw material in a pilot plant, conducting electroreduction experiments on FeSO4 solutions produced from calcination and sulfuric acid leaching processes, ultimately obtaining high-purity metallic iron. This process was the first to use iron ore (pyrite) as raw material to produce metallic iron by electroreduction, producing a total of 1.5 × 10⁻⁶ iron ore between 1955 and 1957. 5A study by WD Badenhorst et al. (DOI: 10.3390 / membranes9110137) found that using a novel BM-5 AEM anion exchange membrane could achieve a current efficiency of 95% in iron electrolysis with an energy consumption of 3.53 kWh / kg iron, which is superior to the existing Pyror process and also shows better stability and lower energy consumption than commercially available AEM membranes. The study also found that when the iron concentration in the solution is below 5 g / L, cathode side reactions lead to a decrease in process efficiency. However, these studies mainly use pyrite or ferrous sulfate as raw materials, with limited research on the broader applications of hematite or magnetite. Patent applications WO2022204379A1 and WO2022197954A1 disclose a method for producing pure iron from iron ore and removing impurities from the solution. This method first involves thermally reducing one or more non-magnetic iron oxide components in the iron ore to form magnetite in the presence of a reducing agent. Then, the magnetite is dissolved in acid to form an acidic iron salt solution. Undissolved impurities are separated and processed. Subsequently, the acidic iron salt is electrolyzed to obtain high-purity iron, and the remaining solution is returned to the acidolysis tank for recycling. However, the reducing agent mentioned in these patents is mainly hydrogen, which is generated through a chemical reaction between iron metal and acid. This method requires the addition of iron metal, increasing costs. Furthermore, this exothermic reaction easily generates a large amount of hydrogen and heat instantaneously, significantly impacting equipment and safety. Furthermore, this method reduces iron ore to magnetite through thermal reduction, specifically by lowering the valence state of some iron in the ore to promote dissolution. This is primarily because a higher degree of iron reduction in the ore results in a higher leaching rate (DOI: 10.3321 / j.issn:1005-3026.2008.12.017). However, the patent does not mention how to achieve efficient iron ore reduction, nor does it address the failure to recover and utilize the heat generated during this process. Additionally, the acid used to dissolve magnetite in this method is highly acidic, while the acidity of the solution recycled back to the acidolysis tank after electrolysis is relatively low, potentially leading to an acidity mismatch that hinders magnetite dissolution. Patent applications WO2022204387A1, WO2022204391A1, and WO2022204394A1 disclose a method for dissolving, converting, and systematically utilizing iron ore. This method involves dissolving iron-containing ore into an acidic iron salt solution and then reacting Fe in a first electrolytic cell. 3+ Reduction to form Fe 2+ The Fe that will be formed subsequently 2+The iron is transferred from the first electrolytic cell to the second electrolytic cell and reduced to high-purity iron, with the remaining solution returned to the dissolving tank. In this method, the first and second electrolytic cells employ proton exchange membranes (PEM) and anion exchange membranes (AEM), respectively. The use of two different types of ion-exchange membranes increases the variety of membranes used in the electrolytic cells, thus increasing operating costs. Furthermore, the patent mentions that the volume of solution entering the cathode chamber in the second electrolytic cell is smaller than the volume entering the anode chamber, increasing process complexity and potentially reducing iron utilization efficiency. Since the patent also uses hydrochloric acid to dissolve magnetite, the introduction of chloride ions can lead to a competing reaction at the anode, increasing the risk of chlorine gas evolution and potentially exacerbating wear on the ion-exchange membrane, further increasing costs. Additionally, the patent does not address the recovery and reuse of the evolved oxygen.

[0009] Vanadium-titanium magnetite is an important source of iron and often contains abundant vanadium, titanium, and other beneficial components, making it highly valuable for comprehensive utilization. Currently, vanadium-titanium magnetite concentrate is mainly processed using blast furnace and non-blast furnace methods. The blast furnace method is the most widely used and technologically mature method for processing vanadium-titanium magnetite resources in my country. This method first agglomerates the vanadium-titanium magnetite, then selectively reduces iron and vanadium oxides in the ore to vanadium-containing molten iron through blast furnace smelting, while titanium enters the slag as titanium dioxide. The vanadium-containing molten iron is then smelted in a converter to obtain vanadium slag and semi-steel. The vanadium slag is processed using a hydrometallurgical process to obtain qualified vanadium products, and the semi-steel is further processed to obtain qualified steel products. However, titanium slag, due to its low titanium dioxide content, complex mineral phases, and predominantly glassy phase, is difficult to effectively recover, resulting in a waste of titanium resources. Furthermore, the blast furnace method has disadvantages such as a long process flow, high infrastructure investment, significant environmental pollution, high capacity consumption, and large carbon dioxide emissions, which are detrimental to achieving my country's overall carbon neutrality goal by 2060.

[0010] Currently, the blast furnace process for processing vanadium-titanium magnetite concentrate suffers from low utilization rates of valuable elements such as vanadium, titanium, and iron, resulting in resource waste. Simultaneously, it faces pressure for low-carbon transformation under the low-carbon context. In acidic solution electroreduction for iron production, the iron-containing electrolyte is generally predominantly ferrous iron (Fe2+), with raw materials mainly derived from pyrite and ilmenite containing Fe2+. However, when using important vanadium-titanium magnetite as raw material, there are fewer reports on its application, and a series of new challenges arise: mismatch between the acid produced at the electroreduction anode and the leaching acidity; mismatch between the final leaching acid and the electroreduction cathode acidity, leading to difficulties in circulating the sulfuric acid medium; intensified acidolysis; water circulation in membrane (ion-exchange membrane) electroreduction; purification of the ferric sulfate solution; and challenges in utilizing the acidolysis / purification residue. In conclusion, given the current status of vanadium-titanium magnetite resources, developing new technologies for the efficient and low-carbon utilization of vanadium-titanium magnetite resources to achieve in-depth development and full utilization of these resources is of paramount importance. Summary of the Invention

[0011] To address the aforementioned problems, this invention proposes a system and method for simultaneously producing low-carbon pure iron, vanadium oxysulfate, titanium dioxide, and high-end sponge titanium from vanadium-titanium iron ore, thereby achieving the preparation of high-purity iron, vanadium oxysulfate, titanium dioxide, and high-end sponge titanium, as well as the recycling of by-product resources.

[0012] To achieve this objective, the present invention employs the following technical solution: A system for simultaneously producing low-carbon pure iron, vanadium oxysulfate, titanium dioxide, and high-end sponge titanium from vanadium-titanium iron ore, the system comprising an acid hydrolysis separation process 1, a dissolution and purification process 2, a valence state adjustment process 3, a battery ironmaking process 4, a vanadium oxysulfate process 5, a titanium dioxide process 6, and a high-end sponge titanium process 7. The acid hydrolysis separation process 1 includes an acid hydrolysis device 1-1 and a vanadium-titanium-iron separation device 1-2; The dissolution and purification process 2 includes a dissolution heat exchange device 2-1, a dissolution filtration device 2-2, a sulfur dioxide heat exchanger 2-3, a high-temperature desulfurization device 2-4, an iron molten metal purification device 2-5, and a solar furnace 2-6. The valence state adjustment process 3 includes an electroreduction device 3-1, a cathode liquid heat exchange device 3-2, and an anolyte heat exchange device 3-3; The battery ironmaking process 4 includes an electrometallurgical unit 4-1 and a sulfuric acid concentration unit 4-2; The vanadium oxysulfate process 5 includes a vanadium liquid purification device 5-1 and a crystallization device 5-2. The titanium dioxide process 6 includes a titanium liquid purification device 6-1, a fine particle hydrolysis device 6-2, a fine particle fluidized bed calcination device 6-3, and a surface modification device 6-4. The high-end sponge titanium process 7 includes a coarse-grain hydrolysis device 7-1, a coarse-grain fluidized bed calcination device 7-2, a fluidized bed chlorination device 7-3, and a magnesium thermal reduction device 7-4. The solid feed inlet of the acidolysis device 1-1 is connected to the feeding pipe of the vanadium-titanium iron ore; the liquid inlet of the acidolysis device 1-1 is connected to the liquid outlet of the sulfuric acid concentration device 4-2 and the liquid outlet of the sulfuric acid solution main pipe through a pipe; the liquid outlet of the acidolysis device 1-1 is connected to the liquid inlet of the vanadium-titanium iron separation device 1-2 through a pipe. The vanadium liquid outlet of the vanadium-titanium-iron separation device 1-2 is connected to the inlet of the vanadium liquid purification device 5-1 via a pipe; the titanium liquid outlet of the vanadium-titanium-iron separation device 1-2 is connected to the inlet of the titanium liquid purification device 6-1 via a pipe; the iron salt outlet of the vanadium-titanium-iron separation device 1-2 is connected to the inlet of the dissolving and filtering device 2-2. The inlet of the dissolution heat exchanger 2-1 is connected to the cathode outlet of the electrometallurgical device 4-1 via a pipe; the outlet of the dissolution heat exchanger 2-1 is connected to the liquid inlet of the dissolution filter 2-2 via a pipe; the air inlet of the dissolution heat exchanger 2-1 is connected to the high-temperature air outlet of the sulfur dioxide heat exchanger 2-3 via a pipe; the air outlet of the dissolution heat exchanger 2-1 supplies low-temperature air for venting. The air inlet of the dissolution filter 2-2 is connected to the low-temperature sulfur dioxide outlet of the sulfur dioxide heat exchanger 2-3 through a pipe; the slag outlet of the dissolution filter 2-2 is connected to the feed inlet of the high-temperature desulfurization device 2-4; and the liquid outlet of the dissolution filter 2-2 is connected to the liquid inlet of the molten iron purification device 2-5 through a pipe. The high-temperature air inlet of the sulfur dioxide heat exchanger 2-3 is connected to the air outlet of the high-temperature desulfurization device 2-4 through a pipeline, and the low-temperature air inlet of the sulfur dioxide heat exchanger 2-3 is connected to an air source; the high-temperature air outlet of the sulfur dioxide heat exchanger 2-3 is connected to the air inlets of the cathode liquid heat exchange device 3-2 and the anolyte heat exchange device 3-3 through a pipeline. The hydrogen inlet of the high-temperature desulfurization device 2-4 is connected to the cathode outlet of the electrometallurgical device 4-1 through a pipeline, and the solid discharge outlet of the high-temperature desulfurization device 2-4 is connected to the cement clinker pipeline. The outlet of the molten iron purification device 2-5 is connected to the inlet of the cathode liquid heat exchange device 3-2 via a pipeline, and the slag outlet of the molten iron purification device 2-5 is connected to the inlet of the high-temperature desulfurization device 2-4. The high-temperature medium outlet of the solar furnace 2-6 is connected to the high-temperature medium inlet of the high-temperature desulfurization device 2-4, and the low-temperature medium inlet of the solar furnace 2-6 is connected to the low-temperature medium outlet of the high-temperature desulfurization device 2-4; the high-temperature medium outlet of the solar furnace 2-6 is connected to the high-temperature medium inlet of the acidolysis device 1-1, and the low-temperature medium inlet of the solar furnace 2-6 is connected to the low-temperature medium outlet of the acidolysis device 1-1; the solar furnace 2-6 receives solar radiation through its light inlet. The anode inlet of the electroreduction device 3-1 is connected to the outlet of the anolyte heat exchanger 3-3 via a pipe; the inlet of the anolyte heat exchanger 3-3 is connected to the dilute sulfuric acid outlet of the sulfuric acid concentration device 4-2 via a pipe; the anode outlet of the electroreduction device 3-1 is connected to the anode inlet of the electrometallurgical device 4-1 via a pipe; the anode outlet of the electroreduction device 3-1 is connected to an oxygen product pipe; the cathode outlet of the electroreduction device 3-1 is connected to the cathode inlet of the electrometallurgical device 4-1 via a pipe; the anode of the electroreduction device 3-1 is connected to the positive electrode of the green electricity via a conductive copper beam; the cathode of the electroreduction device 3-1 is connected to the negative electrode of the green electricity via a conductive copper beam. The outlet of the cathode liquid heat exchanger 3-2 is connected to the cathode liquid inlet of the electroreduction device 3-1 through a pipe; the outlet of the cathode liquid heat exchanger 3-2 supplies low-temperature air for venting; the outlet of the anolyte heat exchanger 3-3 supplies low-temperature air for venting. The anode outlet of the electrometallurgical device 4-1 is connected to the inlet of the sulfuric acid concentration device 4-2 via a pipeline; the anode outlet of the electrometallurgical device 4-1 is connected to an oxygen product pipeline; the cathode outlet of the electrometallurgical device 4-1 is connected to a hydrogen product pipeline; the cathode of the electrometallurgical device 4-1 is designed with an open cathode to obtain pure iron products; the anode of the electrometallurgical device 4-1 is connected to the positive electrode of the green electricity via a conductive copper beam; the cathode of the electrometallurgical device 4-1 is connected to the negative electrode of the green electricity via a conductive copper beam. The outlet of the vanadium liquid purification device 5-1 is connected to the inlet of the crystallization device 5-2 via a pipeline; the outlet of the crystallization device 5-2 is connected to the vanadium oxysulfate product pipeline. The outlet of the titanium liquid purification device 6-1 is connected to the inlet of the fine-particle hydrolysis device 6-2 and the coarse-particle hydrolysis device 7-1 via pipes; the outlet of the fine-particle hydrolysis device 6-2 is connected to the inlet of the fine-particle fluidized bed calcination device 6-3 via pipes; the outlet of the fine-particle fluidized bed calcination device 6-3 is connected to the inlet of the surface modification device 6-4 via pipes; and the outlet of the surface modification device 6-4 is connected to the sulfuric acid process titanium dioxide product pipeline. The outlet of the coarse-grained hydrolysis device 7-1 is connected to the inlet of the coarse-grained fluidized bed calcination device 7-2 via a pipeline; the outlet of the coarse-grained fluidized bed calcination device 7-2 is connected to the inlet of the fluidized bed chlorination device 7-3 via a pipeline; the inlet of the fluidized bed chlorination device 7-3 is connected to the inlets of chlorine gas and carbon powder via a pipeline; the outlet of the fluidized bed chlorination device 7-3 is connected to the inlet of the magnesiac reduction device 7-4 via a pipeline; the inlet of the magnesiac reduction device 7-4 is connected to magnesium ingots via a pipeline; and the outlet of the magnesiac reduction device 7-4 is connected to a pipeline for high-end sponge titanium products.

[0013] This invention also provides a method for simultaneously producing low-carbon pure iron, vanadium oxysulfate, titanium dioxide, and high-end sponge titanium from vanadium-titanium iron ore based on the above system, comprising the following steps: Vanadium-titanium iron ore and concentrated sulfuric acid are reacted in acidolysis unit 1-1 to obtain black titanium liquid; the high-temperature medium circulation of the solar furnace provides heat for the acidolysis process; the black titanium liquid is reacted in vanadium-titanium iron separation unit 1-2 to obtain iron salt crystals, vanadium oxysulfate and titanium oxysulfate; vanadium oxysulfate is sent to vanadium liquid purification unit 5-1; titanium oxysulfate is sent to titanium liquid purification unit 6-1; iron salt crystals enter dissolution and filtration unit 2-2. Iron salt crystals react with a low-concentration ferrous sulfate solution from the dissolution heat exchanger 2-1 and low-temperature sulfur dioxide from the sulfur dioxide heat exchanger 2-3 through the dissolution filtration device 2-2 to obtain a dissolved solution and a dissolved residue. Sulfur dioxide has a reducing effect, which can promote the dissolution of iron salts. The dissolved solution passes through the iron liquid purification device 2-5 to obtain an iron salt solution and a purification residue. The iron salt solution is sent to the cathode chamber of the electro-reduction device 3-1 after heat exchange through the cathode liquid heat exchanger 3-2. The dissolved residue, purification residue, and hydrogen pass through the high-temperature desulfurization device 2-4 to obtain sulfur dioxide and cement clinker. The sulfur dioxide is sent to the dissolution filtration device 2-2 after heat exchange through the sulfur dioxide heat exchanger 2-3. The cement clinker is discharged for treatment. The high-temperature medium circulation of the solar furnace provides heat for the high-temperature desulfurization device. The high-temperature air obtained by heat exchange with the high-temperature sulfur dioxide provides heat for the cathode liquid heat exchange, anolyte heat exchange, and acid hydrolysis heat exchange, respectively, realizing efficient energy utilization in a cascade manner. Iron salt solution and dilute sulfuric acid solution pass through electroreduction device 3-1. At the anode, concentrated sulfuric acid solution and oxygen are obtained, and at the cathode, ferrous sulfate solution is obtained. The concentrated sulfuric acid solution is sent to the anode chamber of electrometallurgical device 4-1, and the oxygen product is collected. The ferrous sulfate solution is sent to the cathode chamber of electrometallurgical device 4-1. Ferrous sulfate solution and concentrated sulfuric acid solution pass through electrometallurgical unit 4-1. At the anode, a high-concentration sulfuric acid solution and oxygen are obtained, while at the cathode, a low-concentration ferrous sulfate solution, pure iron, and hydrogen are obtained. The high-concentration sulfuric acid solution is sent to sulfuric acid concentration unit 4-2 to obtain dilute sulfuric acid solution and concentrated sulfuric acid. The dilute sulfuric acid solution is sent to the anode chamber of electroreduction unit 3-1 after heat exchange in anolyte heat exchanger (3-3). The concentrated sulfuric acid is sent to acidolysis unit 1-1. The low-concentration ferrous sulfate solution is sent to dissolution filtration unit 2-2 after deheating in dissolution heat exchanger (2-1). Pure iron is the final product. Oxygen is collected. Part of the hydrogen is passed into high-temperature desulfurization unit 2-4, and part is collected as hydrogen product. Vanadium oxysulfate is purified by vanadium solution purification device 5-1 to obtain purified vanadium oxysulfate solution; the purified vanadium oxysulfate solution is sent to crystallization device 5-2 to obtain solid-phase vanadium oxysulfate product. Titanium oxysulfate is purified by titanium liquid purification device 6-1 to obtain purified titanium oxysulfate solution; part of the purified titanium oxysulfate solution is sent to fine particle hydrolysis device 6-2 to obtain fine particle metatitanic acid; fine particle metatitanic acid is sent to fine particle fluidized bed calcination device 6-3 to obtain calcined product; calcined product is sent to surface modification device 6-4 to obtain sulfuric acid process titanium dioxide product. After partial purification, the titanium oxysulfate solution is fed into a coarse-grained hydrolysis unit 7-1 to obtain coarse-grained metatitanic acid; the coarse-grained metatitanic acid is fed into a coarse-grained fluidized bed calcination unit 7-2 to obtain coarse-grained titanium dioxide; the coarse-grained titanium dioxide, chlorine gas, and carbon powder are fed into a fluidized bed chlorination unit 7-3 to obtain titanium tetrachloride; titanium tetrachloride and magnesium ingots are fed into a magnesothermic reduction unit 7-4 to obtain high-end sponge titanium products.

[0014] The vanadium-titanium iron ore includes vanadium-titanium magnetite rock ore or vanadium-titanium magnetite placer ore. The vanadium-titanium iron ore also produces a variety of products, including low-carbon pure iron, vanadium oxysulfate, titanium dioxide, high-end sponge titanium, hydrogen, oxygen, and cement substitutes (cement clinker, etc.).

[0015] Preferably, in the electroreduction device 3-1, the diaphragm material is an ion exchange membrane or a porous membrane, wherein the permeation rate of the porous membrane is 1%-40% and the current density is 50 A / m. 2 - 1000 A / m 2 The anode is a lead alloy or titanium-based ruthenium-iridium-tantalum coated electrode, the cathode is made of iron or titanium, and the temperature is 20℃-100℃.

[0016] Preferably, the high-temperature desulfurization devices 2-4 employ fluidized bed or rotary kiln reactors, with a reaction temperature of 1000℃-1500℃ and a desulfurization rate of over 99%.

[0017] Preferably, in the electrometallurgical device 4-1, the diaphragm material is an ion-exchange membrane or a porous membrane, wherein the permeation rate of the porous membrane is 1%-40%, and the current density is 100 A / m. 2 - 2000 A / m2 The anode is a lead alloy or titanium-based ruthenium-iridium-tantalum coated electrode, and the cathode is made of iron, copper, titanium or stainless steel. The reaction temperature is 60℃-100℃, the current efficiency is above 95%, the cathode iron purity is above 99%, and the DC power consumption per ton of iron is less than 3500 kWh.

[0018] One of the features of this invention is that vanadium-titanium iron ore can simultaneously produce low-carbon pure iron, vanadium oxysulfate, titanium dioxide, and high-end sponge titanium.

[0019] The second feature of this invention is that vanadium-titanium iron ore simultaneously achieves efficient utilization of vanadium, titanium, and iron.

[0020] The third feature of this invention is that the iron salt dissolution process achieves the purpose of valence state control and promotes dissolution by reducing ferric ions with sulfur dioxide.

[0021] The fourth feature of this invention is that electroreduction is an adjustment of the valence state.

[0022] The fifth feature of this invention is that electrometallurgy is a battery-powered iron smelting process with no carbon dioxide emissions. The two-step electrolysis process of electroreduction and electrometallurgy reduces the influence of ferric ions and improves production efficiency.

[0023] The sixth feature of this invention is that it obtains oxygen as a byproduct.

[0024] The seventh feature of this invention is: hydrogen recovery and utilization.

[0025] The eighth feature of this invention is that the tailings are completely recycled.

[0026] The ninth feature of this invention is that the iron oxide powder process adopts fluidized bed calcination, which has the purpose of saving energy and improving efficiency.

[0027] The tenth feature of this invention is that the sponge titanium process employs coarse-grained crystallization hydrolysis, including a crystallization fluidized bed process, to obtain high-purity coarse-grained metatitanic acid.

[0028] The eleventh feature of this invention is that high-purity coarse-grained metatitanic acid is obtained by fluidized bed calcination to obtain coarse-grained titanium dioxide, which has the purpose of saving energy and improving efficiency.

[0029] The twelfth feature of this invention is that the coarse-grained hydrolysis process combined with the coarse-grained fluidized bed calcination process can produce coarse-grained titanium dioxide with a purity of over 95% and a particle size greater than 100 micrometers. The coarse-grained titanium dioxide has a particle size range suitable for fluidized bed chlorination, which facilitates fluidized bed chlorination operation.

[0030] The thirteenth feature of this invention is that high-grade titanium dioxide produces almost no chlorination residue during the fluidized bed chlorination process, which is beneficial for continuous system operation.

[0031] The fourteenth feature of this invention is that high-grade titanium dioxide can be used to obtain high-purity titanium tetrachloride, which, through magnesothermic reduction, yields high-end sponge titanium for use in the defense, military, and aerospace fields.

[0032] The fifteenth feature of this invention is that vanadium oxysulfate can be produced through a vanadium-titanium-iron separation process. Vanadium oxysulfate is an important energy storage medium in the field of vanadium batteries.

[0033] The sixteenth feature of this invention is that it employs separate independent circulation of cathodic liquid and anodic liquid, which features simple operation, high production efficiency, and avoids cross-contamination between the anode and cathode liquids. The dilute sulfuric acid solution, after heat exchange in the anodic liquid heat exchanger (3-3), enters the anode chamber of the electroreduction device as the anodic liquid. After electrolysis, the resulting concentrated sulfuric acid solution enters the anode chamber of the electrometallurgical device. The concentrated sulfuric acid solution obtained after electrolysis enters the sulfuric acid concentration device, and the resulting dilute sulfuric acid solution is then circulated back to the anode chamber of the electroreduction device, thus completing the independent circulation of the anodic solution. The high-concentration ferrous sulfate solution, after heat exchange in the cathodic liquid heat exchanger, is passed into the cathode chamber of the electroreduction device. After electrolysis, the resulting ferrous sulfate solution is passed into the cathode chamber of the electrometallurgical device. The resulting low-concentration ferrous sulfate solution, after heat exchange, is passed into the dissolution and filtration device to dissolve iron salt crystals. The dissolved solution, after being purified by molten iron, is then used as the cathodic liquid and passed into the cathode chamber of the electroreduction device, thus completing the independent circulation of the cathodic liquid.

[0034] The seventeenth feature of the present invention is that the battery separator is an ion membrane or a porous membrane, wherein the permeation rate of the porous membrane is 1%-40%.

[0035] The eighteenth feature of this invention is that the energy from acidolysis and high-temperature desulfurization can be recycled by a solar furnace. The high-temperature medium circulation of the solar furnace provides heat for the high-temperature desulfurization and acidolysis processes, achieving low-carbon energy use.

[0036] The nineteenth feature of the present invention is that air can be heated by a sulfur dioxide heat exchanger to provide heat for dissolution heat exchange.

[0037] The twentieth feature of the present invention is that the heat for the electroreduction of the cathode liquid and the anolyte can be provided by the cathode liquid heat exchange device and the anolyte heat exchange device.

[0038] In this invention, sulfur is recycled in the form of sulfuric acid and sulfur dioxide from iron concentrate through acidolysis, purification, electroreduction, electrometallurgy, and high-temperature desulfurization, achieving a complete sulfur cycle without pollutant emissions. A high-temperature desulfurization process is employed to achieve sulfur recycling between the dissolved slag and the purified slag.

[0039] This invention utilizes green energy—solar energy—to provide energy to a high-temperature desulfurization unit using a solar furnace, and then returns the cooled medium to the solar furnace, achieving heat medium recycling. The invention also employs a sulfur dioxide heat exchanger to recover heat from the high-temperature sulfur dioxide generated during desulfurization, which is then used to heat the air medium. This high-temperature air is then used to heat a low-concentration ferrous sulfate solution, catholyte, and anolyte, further improving the system's energy utilization and electrolysis efficiency. The air medium after heat exchange can be directly discharged without the need for waste gas treatment equipment, causing no environmental pollution. The air medium is readily available and can be directly recycled, saving manufacturing costs.

[0040] Compared with the prior art, the present invention has the following outstanding advantages: (1) The energy source for electroreduction and electrometallurgy is green electricity, and the hydrogen and oxygen produced can be recycled and reused; (2) Sulfuric acid solution and sulfur dioxide gas can be recycled within the system without emission, making it safe and environmentally friendly; (3) This process can simultaneously achieve efficient utilization of vanadium, titanium and iron; (4) The entire process is carbon-free; (5) The anode solution and cathode solution of this system are circulated independently, which has the characteristics of simple operation, high production efficiency and avoidance of cross-contamination between anode and cathode solutions.

[0041] (6) The tailings produced can be fully utilized to make cement clinker; (7) The process is simple, the production cost is low, and the product purity is high; (8) The heat in this process can be recycled, minimizing heat loss and reducing energy consumption.

[0042] This invention directly acidifies vanadium-titanium iron ore through an acidolysis separation process, separating vanadium oxysulfate, titanium oxysulfate, and iron salt crystals. A dissolution and purification process promotes the dissolution of iron salts, adjusting the valence state of some iron ions, while simultaneously achieving resource utilization of tailings and sulfur recycling. A valence state adjustment process achieves complete adjustment of iron ion valence states, ensuring that the feed liquid to the electrometallurgical unit is entirely composed of ferrous ions. A battery-powered ironmaking process enables the preparation of high-purity iron, thereby achieving heat recycling, sulfuric acid recycling, recycling of ferrous sulfate solution and water, and recovery of hydrogen and oxygen throughout the system. A vanadium oxysulfate process enables the preparation of vanadium oxysulfate. A titanium dioxide process utilizes fluidized bed calcination technology to produce titanium dioxide via the sulfuric acid process. A high-end sponge titanium process employs a fluidized bed process to obtain high-end sponge titanium for use in defense, military, and aerospace fields. This invention discloses a method for simultaneously producing low-carbon pure iron, vanadium oxysulfate, titanium dioxide, and high-end sponge titanium from vanadium-titanium iron ore. This method not only yields high-purity iron, vanadium oxysulfate, titanium dioxide, and high-end sponge titanium, but also achieves zero carbon emissions throughout the entire process, heat recycling, complete resource utilization of tailings, recycling of byproducts such as sulfuric acid and sulfur dioxide, and recovery and reuse of hydrogen and oxygen. Titanium oxysulfate is produced as sulfuric acid titanium dioxide through fine-particle hydrolysis. High-end sponge titanium is prepared from titanium oxysulfate through coarse-particle hydrolysis, fluidized bed calcination, fluidized bed chlorination, and magnesium thermal reduction. Iron salts undergo a dissolution and purification process to obtain iron salt solution, dissolved slag, and purified slag. High-temperature desulfurization enables resource utilization of the dissolved slag and purified slag, and sulfur recycling. Pure iron is produced through valence state adjustment and battery-powered ironmaking processes, along with sulfuric acid recycling and the recovery and reuse of hydrogen and oxygen. A solar furnace provides heat for the high-temperature desulfurization and acidolysis processes, achieving low-carbon energy consumption. This invention is applicable to the large-scale, continuous processing of vanadium-titanium iron ore to simultaneously produce low-carbon pure iron, vanadium oxysulfate, titanium dioxide, and high-end sponge titanium. It has the advantages of high efficiency, low energy consumption, no pollution, and good economic benefits. Attached Figure Description

[0043] Figure 1 This is a schematic diagram of the configuration of a system for simultaneously producing low-carbon pure iron, vanadium oxysulfate, titanium dioxide, and high-end sponge titanium from vanadium-titanium iron ore, as proposed in this invention.

[0044] Figure label: 1. Acid hydrolysis separation process: 1-1. Acidolysis apparatus; 1-2. Vanadium-titanium-iron separation apparatus; 2. Dissolving and purification process: 2-1. Dissolution heat exchanger; 2-2. Dissolution filtration device; 2-3. Sulfur dioxide heat exchanger; 2-4. High-temperature desulfurization device; 2-5. Molten iron purification device; 2-6. Solar furnace. 3. Price adjustment process: 3-1. Electro-reduction device; 3-2. Cathode liquid heat exchange device; 3-3. Anode liquid heat exchange device; 4. Battery iron smelting process: 4-1. Electrometallurgical equipment; 4-2. Sulfuric acid concentration equipment; 5. Vanadium oxysulfate process: 5-1. Vanadium solution purification device; 5-2. Crystallization device; 6. Titanium dioxide production process: 6-1. Titanium liquid purification device; 6-2. Fine particle hydrolysis device; 6-3. Fine particle fluidized bed calcination device; 6-4. Surface modification device. 7. High-end sponge titanium processing: 7-1. Coarse-grained hydrolysis unit; 7-2. Coarse-grained fluidized bed calcination unit; 7-3. Fluidized bed chlorination unit; 7-4. Magnesium thermal reduction unit. Detailed Implementation

[0045] To make the objectives, technical solutions, and advantages of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. It is worth noting that the embodiments are only used to illustrate the technical solutions of the present invention, and not to limit it.

[0046] Figure 1 This is a schematic diagram of a system and method for simultaneously producing low-carbon pure iron, vanadium oxysulfate, titanium dioxide, and high-end sponge titanium from vanadium-titanium iron ore according to the present invention.

[0047] Example 1 Combination Figure 1 The system used in this embodiment is a system for simultaneously producing low-carbon pure iron, vanadium oxysulfate, titanium dioxide and high-end sponge titanium from vanadium-titanium iron ore. The system includes an acid hydrolysis separation process 1, a dissolution and purification process 2, a valence state adjustment process 3, a battery ironmaking process 4, a vanadium oxysulfate process 5, a titanium dioxide process 6, and a high-end sponge titanium process 7. The acid hydrolysis separation process 1 includes an acid hydrolysis device 1-1 and a vanadium-titanium-iron separation device 1-2; The dissolution and purification process 2 includes a dissolution heat exchange device 2-1, a dissolution filtration device 2-2, a sulfur dioxide heat exchanger 2-3, a high-temperature desulfurization device 2-4, an iron molten metal purification device 2-5, and a solar furnace 2-6. The valence state adjustment process 3 includes an electroreduction device 3-1, a cathode liquid heat exchange device 3-2, and an anolyte heat exchange device 3-3; The battery ironmaking process 4 includes an electrometallurgical unit 4-1 and a sulfuric acid concentration unit 4-2; The vanadium oxysulfate process 5 includes a vanadium liquid purification device 5-1 and a crystallization device 5-2. The titanium dioxide process 6 includes a titanium liquid purification device 6-1, a fine particle hydrolysis device 6-2, a fine particle fluidized bed calcination device 6-3, and a surface modification device 6-4. The high-end sponge titanium process 7 includes a coarse-grain hydrolysis device 7-1, a coarse-grain fluidized bed calcination device 7-2, a fluidized bed chlorination device 7-3, and a magnesium thermal reduction device 7-4. The solid feed inlet of the acidolysis device 1-1 is connected to the feeding pipe of the vanadium-titanium iron ore; the liquid inlet of the acidolysis device 1-1 is connected to the liquid outlet of the sulfuric acid concentration device 4-2 and the liquid outlet of the sulfuric acid solution main pipe through a pipe; the liquid outlet of the acidolysis device 1-1 is connected to the liquid inlet of the vanadium-titanium iron separation device 1-2 through a pipe. The vanadium liquid outlet of the vanadium-titanium-iron separation device 1-2 is connected to the inlet of the vanadium liquid purification device 5-1 via a pipe; the titanium liquid outlet of the vanadium-titanium-iron separation device 1-2 is connected to the inlet of the titanium liquid purification device 6-1 via a pipe; the iron salt outlet of the vanadium-titanium-iron separation device 1-2 is connected to the inlet of the dissolving and filtering device 2-2. The inlet of the dissolution heat exchanger 2-1 is connected to the cathode outlet of the electrometallurgical device 4-1 via a pipe; the outlet of the dissolution heat exchanger 2-1 is connected to the liquid inlet of the dissolution filter 2-2 via a pipe; the air inlet of the dissolution heat exchanger 2-1 is connected to the high-temperature air outlet of the sulfur dioxide heat exchanger 2-3 via a pipe; the air outlet of the dissolution heat exchanger 2-1 supplies low-temperature air for venting. The air inlet of the dissolution filter 2-2 is connected to the low-temperature sulfur dioxide outlet of the sulfur dioxide heat exchanger 2-3 through a pipe; the slag outlet of the dissolution filter 2-2 is connected to the feed inlet of the high-temperature desulfurization device 2-4; and the liquid outlet of the dissolution filter 2-2 is connected to the liquid inlet of the molten iron purification device 2-5 through a pipe. The high-temperature air inlet of the sulfur dioxide heat exchanger 2-3 is connected to the air outlet of the high-temperature desulfurization device 2-4 through a pipeline, and the low-temperature air inlet of the sulfur dioxide heat exchanger 2-3 is connected to an air source; the high-temperature air outlet of the sulfur dioxide heat exchanger 2-3 is connected to the air inlets of the cathode liquid heat exchange device 3-2 and the anolyte heat exchange device 3-3 through a pipeline. The hydrogen inlet of the high-temperature desulfurization device 2-4 is connected to the cathode outlet of the electrometallurgical device 4-1 through a pipeline, and the solid discharge outlet of the high-temperature desulfurization device 2-4 is connected to the cement clinker pipeline. The outlet of the molten iron purification device 2-5 is connected to the inlet of the cathode liquid heat exchange device 3-2 via a pipeline, and the slag outlet of the molten iron purification device 2-5 is connected to the inlet of the high-temperature desulfurization device 2-4. The high-temperature medium outlet of the solar furnace 2-6 is connected to the high-temperature medium inlet of the high-temperature desulfurization device 2-4, and the low-temperature medium inlet of the solar furnace 2-6 is connected to the low-temperature medium outlet of the high-temperature desulfurization device 2-4; the high-temperature medium outlet of the solar furnace 2-6 is connected to the high-temperature medium inlet of the acidolysis device 1-1, and the low-temperature medium inlet of the solar furnace 2-6 is connected to the low-temperature medium outlet of the acidolysis device 1-1; the solar furnace 2-6 receives solar radiation through its light inlet. The anode inlet of the electroreduction device 3-1 is connected to the outlet of the anolyte heat exchanger 3-3 via a pipe; the inlet of the anolyte heat exchanger 3-3 is connected to the dilute sulfuric acid outlet of the sulfuric acid concentration device 4-2 via a pipe; the anode outlet of the electroreduction device 3-1 is connected to the anode inlet of the electrometallurgical device 4-1 via a pipe; the anode outlet of the electroreduction device 3-1 is connected to an oxygen product pipe; the cathode outlet of the electroreduction device 3-1 is connected to the cathode inlet of the electrometallurgical device 4-1 via a pipe; the anode of the electroreduction device 3-1 is connected to the positive electrode of the green electricity via a conductive copper beam; the cathode of the electroreduction device 3-1 is connected to the negative electrode of the green electricity via a conductive copper beam. The outlet of the cathode liquid heat exchanger 3-2 is connected to the cathode liquid inlet of the electroreduction device 3-1 through a pipe; the outlet of the cathode liquid heat exchanger 3-2 supplies low-temperature air for venting; the outlet of the anolyte heat exchanger 3-3 supplies low-temperature air for venting. The anode outlet of the electrometallurgical device 4-1 is connected to the inlet of the sulfuric acid concentration device 4-2 via a pipeline; the anode outlet of the electrometallurgical device 4-1 is connected to an oxygen product pipeline; the cathode outlet of the electrometallurgical device 4-1 is connected to a hydrogen product pipeline; the cathode of the electrometallurgical device 4-1 is designed with an open cathode to obtain pure iron products; the anode of the electrometallurgical device 4-1 is connected to the positive electrode of the green electricity via a conductive copper beam; the cathode of the electrometallurgical device 4-1 is connected to the negative electrode of the green electricity via a conductive copper beam. The outlet of the vanadium liquid purification device 5-1 is connected to the inlet of the crystallization device 5-2 via a pipeline; the outlet of the crystallization device 5-2 is connected to the vanadium oxysulfate product pipeline. The outlet of the titanium liquid purification device 6-1 is connected to the inlet of the fine-particle hydrolysis device 6-2 and the coarse-particle hydrolysis device 7-1 via pipes; the outlet of the fine-particle hydrolysis device 6-2 is connected to the inlet of the fine-particle fluidized bed calcination device 6-3 via pipes; the outlet of the fine-particle fluidized bed calcination device 6-3 is connected to the inlet of the surface modification device 6-4 via pipes; and the outlet of the surface modification device 6-4 is connected to the sulfuric acid process titanium dioxide product pipeline. The outlet of the coarse-grained hydrolysis device 7-1 is connected to the inlet of the coarse-grained fluidized bed calcination device 7-2 via a pipeline; the outlet of the coarse-grained fluidized bed calcination device 7-2 is connected to the inlet of the fluidized bed chlorination device 7-3 via a pipeline; the inlet of the fluidized bed chlorination device 7-3 is connected to the inlets of chlorine gas and carbon powder via a pipeline; the outlet of the fluidized bed chlorination device 7-3 is connected to the inlet of the magnesiac reduction device 7-4 via a pipeline; the inlet of the magnesiac reduction device 7-4 is connected to the inlet of magnesium ingots via a pipeline; and the outlet of the magnesiac reduction device 7-4 is connected to the pipeline for high-end sponge titanium products.

[0048] Example 2 This embodiment employs the system described in Example 1 to process a vanadium-titanium iron ore to simultaneously produce low-carbon pure iron, vanadium oxysulfate, titanium dioxide, and high-end sponge titanium, including the following steps: Vanadium-titanium iron ore and concentrated sulfuric acid are reacted in acidolysis unit 1-1 to obtain black titanium liquid; the high-temperature medium circulation of the solar furnace provides heat for the acidolysis process; the black titanium liquid is reacted in vanadium-titanium iron separation unit 1-2 to obtain iron salt crystals, vanadium oxysulfate and titanium oxysulfate; vanadium oxysulfate is sent to vanadium liquid purification unit 5-1; titanium oxysulfate is sent to titanium liquid purification unit 6-1; iron salt crystals enter dissolution and filtration unit 2-2. Iron salt crystals react with a low-concentration ferrous sulfate solution from the dissolution heat exchanger 2-1 and low-temperature sulfur dioxide from the sulfur dioxide heat exchanger 2-3 through the dissolution filtration device 2-2 to obtain a dissolved solution and a dissolved residue. Sulfur dioxide has a reducing effect, which can promote the dissolution of iron salts. The dissolved solution passes through the iron liquid purification device 2-5 to obtain an iron salt solution and a purification residue. The iron salt solution is sent to the cathode chamber of the electro-reduction device 3-1 after heat exchange through the cathode liquid heat exchanger 3-2. The dissolved residue, purification residue, and hydrogen pass through the high-temperature desulfurization device 2-4 to obtain sulfur dioxide and cement clinker. The sulfur dioxide is sent to the dissolution filtration device 2-2 after heat exchange through the sulfur dioxide heat exchanger 2-3. The cement clinker is discharged for treatment. The high-temperature medium circulation of the solar furnace provides heat for the high-temperature desulfurization device. The high-temperature air obtained by heat exchange with the high-temperature sulfur dioxide provides heat for the cathode liquid heat exchange, anolyte heat exchange, and acid hydrolysis heat exchange, respectively, realizing efficient energy utilization in a cascade manner. Iron salt solution and dilute sulfuric acid solution pass through electroreduction device 3-1. At the anode, concentrated sulfuric acid solution and oxygen are obtained, and at the cathode, ferrous sulfate solution is obtained. The concentrated sulfuric acid solution is sent to the anode chamber of electrometallurgical device 4-1, and the oxygen product is collected. The ferrous sulfate solution is sent to the cathode chamber of electrometallurgical device 4-1. Ferrous sulfate solution and concentrated sulfuric acid solution pass through electrometallurgical unit 4-1. At the anode, high-concentration sulfuric acid solution and oxygen are obtained, while at the cathode, low-concentration ferrous sulfate solution, pure iron, and hydrogen are obtained. The high-concentration sulfuric acid solution is sent to sulfuric acid concentration unit 4-2 to obtain dilute sulfuric acid solution and concentrated sulfuric acid. The dilute sulfuric acid solution is sent to the anode chamber of electroreduction unit 3-1 after heat exchange in anolyte heat exchanger (3-3). The concentrated sulfuric acid is sent to acidolysis unit 1-1. The low-concentration ferrous sulfate solution is heated in dissolution heat exchanger 2-1 and sent to dissolution filtration unit 2-2. Pure iron is the final product. Oxygen is collected. Part of the hydrogen is passed into high-temperature desulfurization unit 2-4, and part is collected as hydrogen product. Vanadium oxysulfate is purified by vanadium solution purification device 5-1 to obtain purified vanadium oxysulfate solution; the purified vanadium oxysulfate solution is sent to crystallization device 5-2 to obtain solid-phase vanadium oxysulfate product. Titanium oxysulfate is purified by titanium liquid purification device 6-1 to obtain purified titanium oxysulfate solution; part of the purified titanium oxysulfate solution is sent to fine particle hydrolysis device 6-2 to obtain fine particle metatitanic acid; fine particle metatitanic acid is sent to fine particle fluidized bed calcination device 6-3 to obtain calcined product; calcined product is sent to surface modification device 6-4 to obtain sulfuric acid process titanium dioxide product. After partial purification, the titanium oxysulfate solution is fed into a coarse-grained hydrolysis unit 7-1 to obtain coarse-grained metatitanic acid; the coarse-grained metatitanic acid is fed into a coarse-grained fluidized bed calcination unit 7-2 to obtain coarse-grained titanium dioxide; the coarse-grained titanium dioxide, chlorine gas, and carbon powder are fed into a fluidized bed chlorination unit 7-3 to obtain titanium tetrachloride; titanium tetrachloride and magnesium ingots are fed into a magnesothermic reduction unit 7-4 to obtain high-end sponge titanium products.

[0049] Example 3 This embodiment uses the system and method of Examples 1-2, taking vanadium-titanium magnetite concentrate from a certain enterprise as the processing target; in acidolysis device 1-1, sulfuric acid acidolysis is used at a reaction temperature of 100 ℃, and the acidolysis rate is 99%; in vanadium-titanium-iron separation device 1-2, iron salt crystallization separation and vanadium oxysulfate extraction separation are performed; in dissolution filtration device 2-2, centrifugal filtration is used; in high-temperature desulfurization device 2-4, a rotary kiln reactor is used at a reaction temperature of 1500 ℃, and the desulfurization rate reaches 99.9%; in electroreduction device 3-1, the diaphragm material is a porous membrane, wherein the permeation rate of the porous membrane is 1%, and the current density is 1000 A / m 2 The reaction temperature is 100 ℃; the anode is a titanium-based ruthenium-iridium-tantalum coated electrode, and the cathode is made of iron; in the electrometallurgical device 4-1, the diaphragm material is a porous membrane, wherein the permeation rate of the porous membrane is 1%, and the current density is 2000 A / m2 The reaction temperature is 100 ℃, the current efficiency is 95%, the cathode iron purity is 99.9%, and the DC power consumption per ton of iron is 3400 kWh; the anode is a lead alloy electrode, and the cathode is made of stainless steel; the solar furnace 2-6 converts solar energy into thermal energy, and the solar heating medium is a mixture of nitrogen and argon gas. The coarse-grained hydrolysis device combined with the coarse-grained fluidized bed calcination device produces coarse-grained titanium dioxide with a purity of 99% and a particle size of 100 micrometers, and the high-end sponge titanium has a purity of 99.9%.

[0050] Example 4 This embodiment uses the system and method of Examples 1-2, taking vanadium-titanium magnetite sand concentrate from a certain enterprise as the processing target; in acidolysis device 1-1, sulfuric acid acidolysis is used, the reaction temperature is 100 ℃, and the acidolysis rate is 99%; in vanadium-titanium-iron separation device 1-2, iron salt crystallization separation and sulfuric acid oxyvanadium extraction separation are performed; in dissolution filtration device 2-2, centrifugal filtration is used; in high-temperature desulfurization device 2-4, a fluidized bed reactor is used, the reaction temperature is 1000 ℃, and the desulfurization rate reaches 99.9%; in electroreduction device 3-1, the diaphragm material is an anion exchange membrane, and the current density is 50 A / m 2 The reaction temperature is 20 ℃; the anode is a titanium-based ruthenium-iridium-tantalum coated electrode, and the cathode is made of iron; in the electrometallurgical device 4-1, the diaphragm material is an anion exchange membrane, and the current density is 100 A / m 2 The reaction temperature is 60℃, the current efficiency is 99%, the cathode iron purity is 99.9%, and the DC power consumption per ton of iron is 3300 kWh. The anode is a lead alloy electrode, and the cathode is made of stainless steel. The solar furnace 2-6 converts solar energy into heat energy, and the solar heating medium is a mixture of nitrogen and argon gas. The coarse-grained hydrolysis device combined with the coarse-grained fluidized bed calcination device produces coarse-grained titanium dioxide with a purity of 95% and a particle size of 150 micrometers. The high-end sponge titanium has a purity of 99%.

[0051] Example 5 This embodiment uses the system and method of Examples 1-2, taking vanadium-titanium magnetite concentrate from a certain enterprise as the processing target; in acidolysis device 1-1, sulfuric acid acidolysis is used, the reaction temperature is 95 ℃, and the acidolysis rate is 99%; in vanadium-titanium-iron separation device 1-2, iron salt crystallization separation and vanadium oxysulfate extraction separation are performed; in dissolution filtration device 2-2, centrifugal filtration is used; high-temperature desulfurization device 2-4 uses a rotary kiln reactor, the reaction temperature is 1500 ℃, and the desulfurization rate reaches 99.9%; in electroreduction device 3-1, the diaphragm material is a porous membrane, wherein the permeation rate of the porous membrane is 40%, and the current density is 500 A / m 2The reaction temperature is 50 ℃; the anode is a titanium-based ruthenium-iridium-tantalum coated electrode, and the cathode is made of iron; in the electrometallurgical device 4-1, the diaphragm material is a porous membrane, wherein the permeation rate of the porous membrane is 40%, and the current density is 300 A / m 2 The reaction temperature is 80 ℃, the current efficiency is 98%, the cathode iron purity is 99.9%, and the DC power consumption per ton of iron is 3400 kWh; the anode is a lead alloy electrode, and the cathode is made of stainless steel; the solar furnace 2-6 converts solar energy into thermal energy, and the solar heating medium is a mixture of nitrogen and argon gas. The coarse-grained hydrolysis device combined with the coarse-grained fluidized bed calcination device produces coarse-grained titanium dioxide with a purity of 98% and a particle size of 150 micrometers, and the high-end sponge titanium has a purity of 99.9%.

[0052] The parts of this invention not described in detail are well-known in the field.

[0053] Of course, the present invention may have many other embodiments. Without departing from the spirit and essence of the present invention, those skilled in the art can make various corresponding changes and modifications according to the disclosure of the present invention, but these corresponding changes and modifications should all fall within the protection scope of the claims of the present invention.

Claims

1. A system for simultaneously producing low-carbon pure iron, vanadium oxysulfate, titanium dioxide, and high-end sponge titanium from vanadium-titanium iron ore, characterized in that, The system includes an acid hydrolysis separation process (1), a dissolution and purification process (2), a valence state adjustment process (3), a battery ironmaking process (4), a vanadium oxysulfate process (5), a titanium dioxide process (6), and a high-end sponge titanium process (7). The acid hydrolysis separation process (1) includes an acid hydrolysis device (1-1) and a vanadium-titanium-iron separation device (1-2); The dissolution and purification process (2) includes a dissolution heat exchange device (2-1), a dissolution filtration device (2-2), a sulfur dioxide heat exchanger (2-3), a high-temperature desulfurization device (2-4), an iron molten metal purification device (2-5), and a solar furnace (2-6); The valence adjustment process (3) includes an electroreduction device (3-1), a cathode liquid heat exchange device (3-2), and an anolyte heat exchange device (3-3); The battery ironmaking process (4) includes an electrometallurgical unit (4-1) and a sulfuric acid concentration unit (4-2); The vanadium oxysulfate process (5) includes a vanadium liquid purification device (5-1) and a crystallization device (5-2); The titanium dioxide process (6) includes a titanium liquid purification device (6-1), a fine particle hydrolysis device (6-2), a fine particle fluidized bed calcination device (6-3), and a surface modification device (6-4); The high-end sponge titanium process (7) includes a coarse-grain hydrolysis device (7-1), a coarse-grain fluidized bed calcination device (7-2), a fluidized bed chlorination device (7-3), and a magnesium thermal reduction device (7-4); The solid feed inlet of the acidolysis device (1-1) is connected to the feeding pipe of the vanadium-titanium iron ore; the liquid inlet of the acidolysis device (1-1) is connected to the liquid outlet of the sulfuric acid concentration device (4-2) and the liquid outlet of the sulfuric acid solution main pipe through a pipe; the liquid outlet of the acidolysis device (1-1) is connected to the liquid inlet of the vanadium-titanium iron separation device (1-2) through a pipe. The vanadium liquid outlet of the vanadium-titanium-iron separation device (1-2) is connected to the inlet of the vanadium liquid purification device (5-1) via a pipe; the titanium liquid outlet of the vanadium-titanium-iron separation device (1-2) is connected to the inlet of the titanium liquid purification device (6-1) via a pipe; the iron salt outlet of the vanadium-titanium-iron separation device (1-2) is connected to the inlet of the dissolution and filtration device (2-2). The inlet of the dissolution heat exchanger (2-1) is connected to the cathode outlet of the electrometallurgical device (4-1) via a pipe; the outlet of the dissolution heat exchanger (2-1) is connected to the liquid inlet of the dissolution filter (2-2) via a pipe; the air inlet of the dissolution heat exchanger (2-1) is connected to the high-temperature air outlet of the sulfur dioxide heat exchanger (2-3) via a pipe; the air outlet of the dissolution heat exchanger (2-1) supplies low-temperature air for venting. The air inlet of the dissolution filter (2-2) is connected to the low-temperature sulfur dioxide outlet of the sulfur dioxide heat exchanger (2-3) through a pipe; the slag outlet of the dissolution filter (2-2) is connected to the feed inlet of the high-temperature desulfurization device (2-4); and the liquid outlet of the dissolution filter (2-2) is connected to the liquid inlet of the molten iron purification device (2-5) through a pipe. The high-temperature inlet of the sulfur dioxide heat exchanger (2-3) is connected to the outlet of the high-temperature desulfurization device (2-4) via a pipe, and the low-temperature inlet of the sulfur dioxide heat exchanger (2-3) is connected to an air source; the high-temperature air outlet of the sulfur dioxide heat exchanger (2-3) is connected to the inlets of the cathode liquid heat exchange device (3-2) and the anolyte liquid heat exchange device (3-3) via a pipe. The hydrogen inlet of the high-temperature desulfurization device (2-4) is connected to the cathode outlet of the electrometallurgical device (4-1) through a pipeline, and the solid discharge outlet of the high-temperature desulfurization device (2-4) is connected to the cement clinker pipeline. The outlet of the molten iron purification device (2-5) is connected to the inlet of the cathode liquid heat exchange device (3-2) through a pipe, and the slag outlet of the molten iron purification device (2-5) is connected to the inlet of the high-temperature desulfurization device (2-4). The high-temperature medium outlet of the solar furnace (2-6) is connected to the high-temperature medium inlet of the high-temperature desulfurization device (2-4), and the low-temperature medium inlet of the solar furnace (2-6) is connected to the low-temperature medium outlet of the high-temperature desulfurization device (2-4); the high-temperature medium outlet of the solar furnace (2-6) is connected to the high-temperature medium inlet of the acidolysis device (1-1), and the low-temperature medium inlet of the solar furnace (2-6) is connected to the low-temperature medium outlet of the acidolysis device (1-1); the solar furnace (2-6) receives solar radiation through its light inlet. The anode inlet of the electroreduction device (3-1) is connected to the outlet of the anolyte heat exchanger (3-3) via a pipe; the inlet of the anolyte heat exchanger (3-3) is connected to the dilute sulfuric acid outlet of the sulfuric acid concentration device (4-2) via a pipe; the anode outlet of the electroreduction device (3-1) is connected to the anode inlet of the electrometallurgical device (4-1) via a pipe; the anode outlet of the electroreduction device (3-1) is connected to the oxygen product pipeline; the cathode outlet of the electroreduction device (3-1) is connected to the cathode inlet of the electrometallurgical device (4-1) via a pipe; the anode of the electroreduction device (3-1) is connected to the positive electrode of the green electricity via a conductive copper beam; the cathode of the electroreduction device (3-1) is connected to the negative electrode of the green electricity via a conductive copper beam. The outlet of the cathode liquid heat exchanger (3-2) is connected to the cathode liquid inlet of the electroreduction device (3-1) through a pipe; the outlet of the cathode liquid heat exchanger (3-2) supplies low-temperature air for venting; the outlet of the anolyte heat exchanger (3-3) supplies low-temperature air for venting. The anode outlet of the electrometallurgical device (4-1) is connected to the inlet of the sulfuric acid concentration device (4-2) via a pipeline; the anode outlet of the electrometallurgical device (4-1) is connected to an oxygen product pipeline; the cathode outlet of the electrometallurgical device (4-1) is connected to a hydrogen product pipeline; the cathode of the electrometallurgical device (4-1) is designed with an open cathode to obtain pure iron products; the anode of the electrometallurgical device (4-1) is connected to the positive electrode of the green electricity via a conductive copper beam; the cathode of the electrometallurgical device (4-1) is connected to the negative electrode of the green electricity via a conductive copper beam. The outlet of the vanadium liquid purification device (5-1) is connected to the inlet of the crystallization device (5-2) via a pipeline; the outlet of the crystallization device (5-2) is connected to the vanadium oxysulfate product pipeline. The outlet of the titanium liquid purification device (6-1) is connected to the inlet of the fine-particle hydrolysis device (6-2) and the coarse-particle hydrolysis device (7-1) via pipes; the outlet of the fine-particle hydrolysis device (6-2) is connected to the inlet of the fine-particle fluidized bed calcination device (6-3) via pipes; the outlet of the fine-particle fluidized bed calcination device (6-3) is connected to the inlet of the surface modification device (6-4) via pipes; and the outlet of the surface modification device (6-4) is connected to the sulfuric acid process titanium dioxide product pipeline. The outlet of the coarse-grained hydrolysis device (7-1) is connected to the inlet of the coarse-grained fluidized bed calcination device (7-2) via a pipeline; the outlet of the coarse-grained fluidized bed calcination device (7-2) is connected to the inlet of the fluidized bed chlorination device (7-3) via a pipeline; the inlet of the fluidized bed chlorination device (7-3) is connected to the inlets of chlorine gas and carbon powder via a pipeline; the outlet of the fluidized bed chlorination device (7-3) is connected to the inlet of the magnesiac reduction device (7-4) via a pipeline; the inlet of the magnesiac reduction device (7-4) is connected to the inlet of magnesium ingots via a pipeline; and the outlet of the magnesiac reduction device (7-4) is connected to the pipeline for high-end sponge titanium products.

2. A method for simultaneously producing low-carbon pure iron, vanadium oxysulfate, titanium dioxide, and high-end sponge titanium from vanadium-titanium iron ore based on the system described in claim 1, comprising the following steps: Vanadite is reacted with concentrated sulfuric acid in an acidolysis apparatus (1-1) to produce black titanium solution; The high-temperature medium circulation of the solar furnace provides heat for the acidolysis process; the black titanium liquid is separated into iron salt crystals, vanadium oxysulfate and titanium oxysulfate by the vanadium-titanium-iron separation device (1-2); the vanadium oxysulfate is sent to the vanadium liquid purification device (5-1); the titanium oxysulfate is sent to the titanium liquid purification device (6-1); the iron salt crystals enter the dissolution and filtration device (2-2). Iron salt crystals react with a low-concentration ferrous sulfate solution from the dissolution heat exchanger (2-1) and low-temperature sulfur dioxide from the sulfur dioxide heat exchanger (2-3) through the dissolution filtration device (2-2) to obtain an acid hydrolysis solution and a dissolution residue. Sulfur dioxide has a reducing effect and can promote the dissolution of iron salts. The acid hydrolysis solution passes through the iron liquid purification device (2-5) to obtain an iron salt solution and a purification residue. The iron salt solution is sent to the cathode chamber of the electro-reduction device (3-1) after heat exchange through the cathode liquid heat exchanger (3-2). The dissolution residue, purification residue, and hydrogen pass through the high-temperature desulfurization device (2-4) to obtain sulfur dioxide and cement clinker. The sulfur dioxide is sent to the dissolution filtration device (2-2) after heat exchange through the sulfur dioxide heat exchanger (2-3). The cement clinker is discharged for treatment. The high-temperature medium circulation of the solar furnace provides heat for the high-temperature desulfurization device (2-4). The high-temperature air obtained by heat exchange between air and high-temperature sulfur dioxide provides heat for the cathode liquid heat exchange, anolyte heat exchange, and dissolution heat exchange, respectively, realizing efficient energy utilization in a cascade manner. Iron salt solution and dilute sulfuric acid solution are passed through an electro-reduction device (3-1). At the anode, concentrated sulfuric acid solution and oxygen are obtained, and at the cathode, ferrous sulfate solution is obtained. Concentrated sulfuric acid solution is fed into the anode chamber of the electrometallurgical unit (4-1) for oxygen product collection; Ferrous sulfate solution is fed into the cathode chamber of the electrometallurgical unit (4-1); Ferrous sulfate solution and concentrated sulfuric acid solution pass through an electrometallurgical unit (4-1). At the anode, a high-concentration sulfuric acid solution and oxygen are obtained, while at the cathode, a low-concentration ferrous sulfate solution, pure iron, and hydrogen are obtained. The high-concentration sulfuric acid solution is sent to a sulfuric acid concentration unit (4-2) to obtain a dilute sulfuric acid solution and concentrated sulfuric acid. The dilute sulfuric acid solution is sent to an anolyte heat exchanger (3-3) after heat exchange. The concentrated sulfuric acid is sent to an acidolysis unit (1-1). The low-concentration ferrous sulfate solution enters a dissolution heat exchanger (2-1) for heating and then enters a dissolution filtration unit (2-2) to dissolve the iron salt solution. Pure iron is the final product. The oxygen product is collected. Part of the hydrogen is passed into a high-temperature desulfurization unit (2-4), and part is collected as a hydrogen product. Vanadium oxysulfate is purified by a vanadium solution purification device (5-1) to obtain a purified vanadium oxysulfate solution; the purified vanadium oxysulfate solution is then sent to a crystallization device (5-2) to obtain a solid-phase vanadium oxysulfate product. Titanium oxysulfate is purified by a titanium liquid purification device (6-1) to obtain a purified titanium oxysulfate solution; part of the purified titanium oxysulfate solution is sent to a fine-particle hydrolysis device (6-2) to obtain fine-particle metatitanic acid; the fine-particle metatitanic acid is sent to a fine-particle fluidized bed calcination device (6-3) to obtain the calcined product. The calcined product is fed into a surface modification device (6-4) to obtain sulfuric acid process titanium dioxide product; After partial purification, the titanium oxysulfate solution is sent to a coarse-grained hydrolysis unit (7-1) to obtain coarse-grained metatitanic acid; the coarse-grained metatitanic acid is sent to a coarse-grained fluidized bed calcination unit (7-2) to obtain coarse-grained titanium dioxide; the coarse-grained titanium dioxide, chlorine gas, and carbon powder are sent to a fluidized bed chlorination unit (7-3) to obtain titanium tetrachloride; titanium tetrachloride and magnesium ingots are sent to a magnesothermic reduction unit (7-4) to obtain high-end sponge titanium products.

3. The method for simultaneously producing low-carbon pure iron, vanadium oxysulfate, titanium dioxide, and high-end sponge titanium from vanadium-titanium iron ore according to claim 2, characterized in that, In the electroreduction device (3-1), the diaphragm material is an ion-exchange membrane or a porous membrane, wherein the permeation rate of the porous membrane is 1%-40%, and the current density is 50A / m. 2 -1000A / m 2 The anode is a lead alloy or titanium-based ruthenium-iridium-tantalum coated electrode, the cathode is made of iron or titanium, and the temperature is 20℃-100℃.

4. The method for simultaneously producing low-carbon pure iron, vanadium oxysulfate, titanium dioxide, and high-end sponge titanium from vanadium-titanium iron ore according to claim 2, characterized in that, The high-temperature desulfurization device (2-4) adopts a fluidized bed or rotary kiln reactor, with a reaction temperature of 1000℃-1500℃ and a desulfurization rate of over 99%.

5. The method for simultaneously producing low-carbon pure iron, vanadium oxysulfate, titanium dioxide, and high-end sponge titanium from vanadium-titanium iron ore according to claim 2, characterized in that, In the electrometallurgical device (4-1), the diaphragm material is an ion-exchange membrane or a porous membrane, wherein the permeation rate of the porous membrane is 1%-40%, and the current density is 100A / m. 2 -2000A / m 2 The anode is a lead alloy or titanium-based ruthenium-iridium-tantalum coated electrode, and the cathode is made of iron, copper, titanium or stainless steel. The reaction temperature is 60℃-100℃, the current efficiency is above 95%, the cathode iron purity is above 99%, and the DC power consumption per ton of iron is less than 3500kWh.

6. The method for simultaneously producing low-carbon pure iron, vanadium oxysulfate, titanium dioxide, and high-end sponge titanium from vanadium-titanium iron ore according to claim 2, characterized in that, The vanadium-titanium iron ore includes vanadium-titanium magnetite rock ore or vanadium-titanium magnetite placer ore.

7. The method for simultaneously producing low-carbon pure iron, vanadium oxysulfate, titanium dioxide, and high-end sponge titanium from vanadium-titanium iron ore according to claim 2, characterized in that, Vanadium-titanium iron ore also produces a variety of products, including low-carbon pure iron, vanadium oxysulfate, titanium dioxide, high-end sponge titanium, hydrogen, oxygen, and cement substitutes.

8. The method for simultaneously producing low-carbon pure iron, vanadium oxysulfate, titanium dioxide, and high-end sponge titanium from vanadium-titanium iron ore according to claim 2, characterized in that, The iron salt dissolution and purification process utilizes the reducing effect of sulfur dioxide to promote dissolution.

9. The method for simultaneously producing low-carbon pure iron, vanadium oxysulfate, titanium dioxide, and high-end sponge titanium from vanadium-titanium iron ore according to claim 2, characterized in that, The cathode and anolyte are circulated independently, which is characterized by simple operation, high production efficiency, and avoidance of cross-contamination between the cathode and anolyte.

10. A method for simultaneously producing low-carbon pure iron, vanadium oxysulfate, titanium dioxide, and high-end sponge titanium from vanadium-titanium iron ore according to claim 2, characterized in that, A high-temperature desulfurization process is adopted to achieve sulfur recycling between dissolved slag and purified slag.

11. The method for simultaneously producing low-carbon pure iron, vanadium oxysulfate, titanium dioxide, and high-end sponge titanium from vanadium-titanium iron ore according to claim 2, characterized in that, The coarse-grained hydrolysis device, combined with the coarse-grained fluidized bed calcination device, produces coarse-grained titanium dioxide with a purity of over 95% and a particle size greater than 100 micrometers.

12. The method for simultaneously producing low-carbon pure iron, vanadium oxysulfate, titanium dioxide, and high-end sponge titanium from vanadium-titanium iron ore according to claim 2, characterized in that, The solar furnace (2-6) converts solar energy into thermal energy to heat the medium, and the heated medium provides heat to the acid hydrolysis device (1-1) and the high-temperature desulfurization device (2-4); the medium is a molten salt composed of one or more of the elements silicon, sodium, oxygen, calcium and aluminum; or the medium is nitrogen, argon or a mixture thereof.

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