A method for smelting ferroniobium and enriching rare earth and titanium

Abstract

The present invention relates to a method for smelting ferroniobium and enriching rare earths and titanium, comprising: S1, providing a co-existing ore or metallurgical slag containing niobium, titanium, rare earths, and iron; S2, adding a modifier and a siliceous reducing agent, and after high-temperature smelting and reduction, obtaining a layered ferroniobium alloy melt and a slag containing rare earths and titanium; S3, controlling the temperature and cooling the slag containing rare earths and titanium to room temperature, so that the rare earths and titanium in the slag are directionally precipitated and grown in a perovskite phase; S4, crushing and grinding the cooled slag, and obtaining a rare earth-rich perovskite concentrate by flotation. The present invention utilizes a siliceous reducing agent to selectively reduce multiple metal elements in the co-existing ore or metallurgical slag containing rare earths, niobium, titanium, and iron. The method selectively reduces iron oxides and niobium oxides in the material in a high-temperature molten state, avoiding the reduction of titanium oxides and rare earth oxides. The method successfully smelts a ferroniobium alloy melt, obtaining a high-grade ferroniobium alloy melt and a high-grade rare earth-rich perovskite concentrate.

Description

Technical Field

[0001] The present invention relates to the technical field of niobium resource utilization, and in particular to a method for smelting ferroniobium and enriching rare earth and titanium. Background Art

[0002] The Bayan Obo mine is a world-renowned polymetallic ore containing rare earths, niobium, titanium, and iron. With 43.5 million tons of rare earth reserves, it ranks first in the world, and 6.6 million tons of niobium reserves, it ranks second. However, the development and utilization of Bayan Obo's mineral resources primarily focuses on iron extraction, with the utilization rate of rare earth resources less than 10%, and that of niobium and titanium almost zero. Niobium resources are indispensable in modern industry and cutting-edge technology. The low utilization rate of rare earth, niobium, and titanium resources is primarily due to the low grade of the resources, the diverse mineral diversity, and the fine grain size of the embedded minerals.

[0003] With advances in mineral processing technology, niobium concentrates with Nb2O5 grades of 1-6% can now be extracted from the Bayan Obo co-existing ore. For example, patent CN201310194096.5, "A Process for Recovering Niobium from Baotou Rare Earth Tailings," describes a process that involves preferential desulfurization, fluorite separation, iron separation, and niobium separation. Niobium concentrates with Nb2O5 grades of 5-6% can be extracted from Baotou rare earth tailings through a process that includes prioritizing desulfurization, fluorite separation, iron separation, and niobium separation. This process also contains a certain amount of iron, rare earths, and titanium, resulting in a low-grade product. Patent CN201310449481.X discloses a "Method for Preparing Niobium-Titanium Ferroalloy by Carbon Reduction and Niobium-Titanium Ferroalloy." This process proposes a "carbon-high-temperature reduction-graphite powder secondary reduction" process for smelting niobium-ferroalloy melts, using carbon-thermal reduction of high-titanium, niobium-rich slag to produce niobium-titanium ferroalloy. Patent CN201310449614.3 discloses a "method for preparing niobium-titanium-ferroalloy and niobium-titanium-ferroalloy," proposing a "high-temperature carburization-reoxidation" process for smelting niobium-titanium-ferroalloy melts. Niobium-titanium-ferroalloy is prepared through carbothermal reduction and reoxidation of high-titanium, niobium-rich slag. CN201410840076.5 discloses a "method for preparing low-grade niobium-titanium-ferroalloy," using niobium-titanium concentrate as the raw material. The niobium-titanium-ferroalloy is produced in three steps: gas-solid selective reduction, electric furnace smelting, and electric furnace smelting. The process utilizes carbonaceous reducing agents such as semi-coke, pulverized coal, coke powder, and pitch coke for carbothermal reduction. CN112410586A discloses a method for smelting niobium, rare earths, and titanium from a polymetallic ore containing iron, niobium, and rare earths. The method employs carbon reduction, adjusts the oxygen potential in the furnace and the CaO / SiO2 mass ratio to a suitable range by controlling the composition of the ingredients and the oxygen potential in the furnace, and monitoring the composition of the smelting output and the iron recovery rate. The CaO / SiO2 mass ratio of the slag is 0.8-2.3. The method produces a high-grade concentrate containing niobium, rare earths, and titanium, and a high-grade rare earth concentrate. The niobium, rare earth, and titanium concentrate has an Nb2O5 content of 24.31%, an REO content of 7.74%, and a TiO2 content of 15.61%. The high-grade rare earth concentrate has an REO content of 23.46%. Both concentrates are obtained by carbon reduction.

[0004] As can be seen from the existing technology, in the niobium-titanium concentrate smelting process, carbon is usually used as a reducing agent to reduce the metal elements. However, at high temperatures, carbon will react with elements such as niobium and titanium in the slag to form carbides. Niobium and titanium carbides are both high-melting-point compounds (the melting point of NbC is 3500°C, and the melting point of TiC is 3067°C), which are difficult to dissolve in the slag and have strong wettability with the slag. Once formed, niobium and titanium carbides will wrap around iron droplets. Their strong wettability with the slag enhances the stability of the emulsion, making the separation of iron droplets from the slag difficult. Therefore, a niobium carbide retention zone can be found at the slag-iron interface, which to some extent affects the mass transfer of niobium to the molten iron. During the ferroniobium smelting process, the production of niobium and titanium carbides causes the slag to be extremely viscous and severely foamy, making slag-iron separation very difficult and even causing charge splashing accidents. Furthermore, as described in the aforementioned technical solutions, the ferroniobium alloy melt obtained by smelting with carbon as a reducing agent typically contains a high content of titanium. The simultaneous presence of niobium and titanium reduces the alloy's application value and scope of use. The difficulty in separating niobium and titanium becomes another challenge in the carbon thermal reduction smelting process for ferroniobium. In summary, although existing solutions can smelt ferroniobium alloy melts using carbon as a reducing agent, the precipitation of niobium and titanium carbides causes the smelting process to be disrupted, and the difficulty in separating niobium and titanium reduces the quality of the alloy product. Furthermore, the rare earth and titanium grades in the slags of these solutions do not meet the requirements for rare earth concentrates and titanium concentrates, and their recycling value is low. Summary of the Invention

[0005] In view of the above-mentioned shortcomings and deficiencies of the prior art, the present invention provides a method for smelting ferroniobium and enriching rare earths and titanium, which can obtain a ferroniobium alloy melt and a high-grade rare earth-rich perovskite concentrate.

[0006] (2) Technical solution

[0007] In order to solve the above problems, the present invention provides a method for smelting ferroniobium and enriching rare earth and titanium, comprising:

[0008] S1. Provide associated ores or metallurgical slag containing niobium, titanium, rare earth and iron;

[0009] S2, adding a modifier and a siliceous reducing agent, and performing high-temperature smelting and reduction to obtain a layered ferroniobium alloy melt and a slag containing rare earth and titanium;

[0010] S3, separating the rare earth and titanium-containing slag and cooling it to room temperature under controlled temperature, so that the rare earth and titanium in the slag are directionally precipitated and grown in the perovskite phase;

[0011] S4. Crushing and grinding the cooled slag to obtain rare earth-rich perovskite concentrate through flotation.

[0012] Optionally, in S1, the iron grade T.Fe in the associated ore or metallurgical slag containing niobium, titanium, rare earth and iron is 0-55%, and contains Nb2O51-15%, TiO21-15%, REO1-15%, SiO25%-30%, CaO2%-20% and F2-15% by weight.

[0013] Optionally, in S2, the modifier is one or more of dolomite, limestone and quartz.

[0014] Optionally, in S2, the siliceous reducing agent is one or more of ferrosilicon alloy, ferroaluminum-silicon alloy, calcium-silicon alloy, and silicon carbide. The siliceous reducing agent can selectively reduce niobium oxide and iron oxide in co-existing ore or metallurgical slag to obtain a ferroniobium alloy melt.

[0015] Optionally, in S2, by selecting a corresponding modifier and controlling its addition amount, the CaO / SiO2 weight ratio in the slag is set to 0.9-2.3, thereby ensuring that perovskite is precipitated from the slag during the cooling process.

[0016] Optionally, in S2, the high-temperature smelting reduction is carried out in a submerged arc furnace or an electric arc furnace, the smelting temperature is 1200°C-1500°C, and the smelting time is ≥10 min.

[0017] Optionally, in S3, the temperature-controlled cooling method is: firstly controlling the temperature to cool to 1000-1300° C. and keeping the temperature for more than 60 minutes, and then naturally cooling to room temperature.

[0018] Optionally, the method further includes casting the ferroniobium alloy melt into a mold.

[0019] Optionally, the ferroniobium alloy melt contains 40-95% Fe, 3-55% Nb, ≤5% Si, and ≤1% Ti in weight percentage.

[0020] Optionally, in S4, the rare earth-rich perovskite concentrate contains TiO2 25%-40%, REO 30-45%, CaO 25-40% by weight, and the remainder is impurities.

[0021] (3) Beneficial effects

[0022] The present invention utilizes the moderate reducing power of silicon and uses a siliceous reducing agent to reduce co-existing ores or metallurgical slag containing rare earth, niobium, titanium, and iron. The siliceous reducing agent selectively reduces iron oxides and niobium oxides in the material in a high-temperature molten state, while avoiding the reduction of titanium oxides and rare earth oxides. This successfully produces a ferroniobium alloy melt, solving the problem of high titanium impurity content in products produced by the prior art carbothermic reduction process. It also avoids the formation of niobium carbides and titanium carbides, and solves the problems of incomplete slag-iron separation, slag foaming, and charge splashing caused by excessive slag viscosity in the carbothermic reduction process. Furthermore, the present invention adds a modifier to control the slag composition during the high-temperature smelting reduction process, and uses a slag cooling system to induce directional crystallization and growth of rare earth and titanium in the perovskite phase, creating favorable mineral phase conditions for the beneficiation and enrichment of rare earth and titanium. A rare earth-rich perovskite concentrate is then obtained by flotation. This concentrate does not require further enrichment and has high recycling value, achieving the comprehensive extraction and utilization of niobium, titanium, rare earth, and titanium. Among them, the crystallization temperature of the slag is controlled by taking advantage of the high temperature state of the slag obtained from ferroniobium smelting. There is no need to reheat the slag, and the heat utilization efficiency is high. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a flow chart of the method for smelting ferroniobium and enriching rare earth and titanium according to the present invention;

[0024] Figure 2 It is the thermodynamic oxygen potential diagram of the present invention.

[0025] Figure 3 This is a SEM image of the slag after crystallization of the present invention. DETAILED DESCRIPTION

[0026] In order to better explain the present invention and facilitate understanding, the present invention is described in detail below through specific implementation methods in conjunction with the accompanying drawings.

[0027] A method for smelting ferroniobium and enriching rare earth and titanium, provided in an embodiment of the present invention, comprises:

[0028] S1. Provide associated ores or metallurgical slag containing niobium, titanium, rare earth and iron;

[0029] S2, adding a modifier and a siliceous reducing agent, and performing high-temperature smelting and reduction to obtain a layered ferroniobium alloy melt and a slag containing rare earth and titanium;

[0030] S3, separating the rare earth and titanium-containing slag and cooling it to room temperature under controlled temperature, so that the rare earth and titanium in the slag are directionally precipitated and grown in the perovskite phase;

[0031] S4. Crushing and grinding the cooled slag to obtain rare earth-rich perovskite concentrate through flotation.

[0032] The present invention utilizes the moderate reducing power of silicon and uses a siliceous reducing agent to reduce co-existing ores or metallurgical slag containing rare earth, niobium, titanium, and iron. In a high-temperature molten state, the siliceous reducing agent selectively reduces iron oxides and niobium oxides in the material, while avoiding the reduction of titanium oxides and rare earth oxides. This successfully produces a ferroniobium alloy melt, resolving the problem of high titanium impurity content in products produced by the prior art carbothermic reduction process. It also avoids the formation of niobium carbides and titanium carbides, and solves the problems of incomplete slag-iron separation, slag foaming, and charge splashing caused by excessive slag viscosity in the carbothermic reduction process. Furthermore, the present invention adds a modifier to regulate the slag composition during the high-temperature smelting reduction process, and uses a slag cooling system to induce directional crystallization and growth of rare earth and titanium in the perovskite phase, creating favorable mineral phase conditions for the beneficiation and enrichment of rare earth and titanium. A rare earth-rich perovskite concentrate is then obtained by flotation. This concentrate does not require further enrichment and has high recycling value, achieving the comprehensive extraction and utilization of niobium, titanium, rare earth, and titanium. Among them, the crystallization temperature of the slag is controlled by taking advantage of the high temperature state of the slag obtained from ferroniobium smelting. There is no need to reheat the slag, and the heat utilization efficiency is high.

[0033] To better understand the above technical solutions, exemplary embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. Although exemplary embodiments of the present invention are shown in the accompanying drawings, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments described herein. Instead, these embodiments are provided to enable a clearer and more thorough understanding of the present invention and to fully convey the scope of the present invention to those skilled in the art.

[0034] See also Figure 1-3 The present invention provides a method for smelting ferroniobium and enriching rare earth and titanium, comprising:

[0035] S1. Provide associated ores or metallurgical slag containing niobium, titanium, rare earth and iron.

[0036] The raw materials are commensurate ores or metallurgical slag containing niobium, titanium, rare earth and iron, wherein the iron grade T.Fe in the commensurate ores or metallurgical slag is 0-55%, and the weight percentage of Nb2O5

[0037] 1-15%, TiO21-15%, REO1-15%, SiO25%-30%, CaO2%-20% and F2-15%. The smelting raw materials can be original co-existing ores or processed metallurgical slag.

[0038] S2, adding a modifier and a siliceous reducing agent, and performing high-temperature smelting and reduction to obtain a layered ferroniobium alloy melt and a slag containing rare earth and titanium;

[0039] Specifically, the modifier can be one or more of dolomite, limestone, and quartz. The siliceous reducing agent can be one or more of ferrosilicon, ferroaluminum-silicon, calcium-silicon alloy, and silicon carbide. In a high-temperature molten state, the siliceous reducing agent's moderate reducing properties selectively reduce niobium oxide and iron oxide in co-existing ores or metallurgical slag, avoiding the reduction of titanium oxide and rare earth oxides. This successfully smelts a ferroniobium alloy melt, producing a ferroniobium alloy melt and a slag containing rare earths and titanium. The ferroniobium alloy melt and slag are separated by density differences.

[0040] Specifically, the CaO / SiO2 weight ratio in the slag is 0.9-2.3. Since the raw materials contain 5%-30% SiO2 and 20% CaO2, when adding modifiers and reducing agents, it is necessary to determine the amount of reducing agent required based on the niobium oxide and iron oxide in the raw materials. In addition, it is also necessary to determine the type of modifier and the final amount of reducing agent added in combination with the amount of CaO / SiO2 in the raw materials. Ensure that niobium oxide and iron oxide in co-existing ores or metallurgical slag can be selectively reduced. In addition, it is also necessary to ensure that the CaO / SiO2 weight ratio in the slag is 0.9-2.3, so that the rare earth and titanium in the slag can be directionally precipitated in the perovskite phase.

[0041] In one embodiment, the ferroniobium alloy melt may be cast and formed. The ferroniobium alloy contains 40-95% Fe, 3-55% Nb, ≤5% Si, and ≤1% Ti by weight.

[0042] In one embodiment, the high-temperature smelting reduction is carried out in a submerged arc furnace or an electric arc furnace, the smelting temperature is 1200° C.-1500° C., and the smelting time is ≥10 min.

[0043] S3, cooling the slag containing rare earth and titanium to room temperature under controlled temperature control, so that the rare earth and titanium in the slag are directionally precipitated and grown in the perovskite phase;

[0044] The controlled cooling method in S3 can be: first, cooling to 1000-1300°C and holding for at least 60 minutes, followed by natural cooling to room temperature. This cooling method induces the directional crystallization and growth of rare earth and titanium in the perovskite phase during the slag cooling process, creating favorable mineralization conditions for their concentration and enrichment. The slag crystallization control process is carried out at the high temperature of the slag obtained from ferroniobium smelting, eliminating the need for secondary slag heating and achieving high heat utilization efficiency.

[0045] S4. Crushing and grinding the cooled slag, and obtaining rare earth-rich perovskite concentrate by flotation. Specifically, the rare earth-rich perovskite concentrate contains 25%-40% TiO2, 30-45% REO, 25-40% CaO, and the remainder being impurities.

[0046] In the present invention, a siliceous reducing agent is used to perform high-temperature melting reduction on the associated ores or metallurgical slag containing rare earth, niobium, titanium and iron. Figure 2 The thermodynamic oxygen potential diagram shown in the figure shows that the binding ability of silicon with oxygen is between niobium and titanium. Therefore, silicon is a suitable reducing agent for selective reduction between niobium and titanium. The use of silicon reducing agents can completely avoid the formation of niobium carbide and titanium carbide during the smelting process, solving the problem of process irregularities.

[0047] The present invention utilizes thermodynamic oxygen potential diagrams to select reducing agents for ferroniobium smelting. It utilizes siliceous reducing agents instead of traditional carbonaceous reducing agents for the selective reduction of multiple metal elements in co-existing ores or metallurgical slag containing rare earth, niobium, titanium, and iron. This selective reduction of iron and niobium oxides in the molten material at high temperatures avoids the reduction of titanium and rare earth oxides, successfully producing a ferroniobium alloy melt and resolving the issue of high titanium impurity content in the product during carbothermal reduction. Furthermore, the method provided by the present invention avoids the formation of niobium and titanium carbides, addressing the issues of incomplete slag-iron separation, slag foaming, and charge splashing caused by excessive slag viscosity during carbothermal reduction.

[0048] Dolomite, limestone, and quartz are used as modifiers to control the composition of the smelting slag. A specific cooling system is also designed to induce the directional crystallization and growth of rare earths and titanium in the perovskite phase (a single mineral phase) during the slag cooling process. This creates favorable mineral phase conditions for the beneficiation and enrichment of rare earths and titanium. Furthermore, through slag crushing, grinding, and flotation, a rare earth-rich perovskite concentrate is obtained, achieving the comprehensive extraction and utilization of niobium, titanium, rare earths, and titanium. Slag crystallization is controlled by maintaining the high temperature of the slag from ferroniobium smelting, eliminating the need for secondary slag heating and achieving high heat utilization efficiency.

[0049] Example

[0050] The co-existing ore containing niobium, titanium, rare earth and iron used in the following examples was obtained from the Bayan Obo mine. The metallurgical slag containing niobium, titanium, rare earth and iron used was produced during the smelting process of the Bayan Obo mine.

[0051] Example 1

[0052] (1) The main raw material is a co-existing ore containing niobium, titanium, rare earth and iron. The iron grade of the co-existing ore is 19.1%, and the weight percentages are Nb2O55.7%, TiO211.7%, REO9.1%, SiO219.9%, CaO5.7% and F5.7%. Limestone is added as a modifier and ferrosilicon alloy is added as a reducing agent. High-temperature smelting and reduction are carried out in a submerged arc furnace at a smelting temperature of 1500°C and a smelting time of 10 minutes. During the smelting process, the CaO / SiO2 weight ratio in the slag is controlled to be 2.0. Niobium oxide and iron oxide in the co-existing ore are selectively reduced, thereby achieving separation of niobium and iron from rare earth and titanium. A ferroniobium alloy melt and a slag containing rare earth and titanium are obtained. The ferroniobium alloy melt and the slag are separated due to density differences.

[0053] (2) Casting a ferroniobium alloy melt, wherein the ferroniobium alloy contains 82.2% of Fe, 15.3% of Nb, 1.3% of Si, and 0.3% of Ti according to weight percentage.

[0054] (3) The slag is cooled to 1250°C, kept at this temperature for 240 minutes, and then cooled naturally to room temperature. The rare earth and titanium in the slag precipitate and grow directionally in the perovskite phase, such as Figure 3 This shows that by regulating the composition of the smelting slag and combining it with a specific cooling system, the rare earth and titanium can be crystallized and grown in the perovskite phase in a directional manner during the cooling process.

[0055] (4) The cooled slag is crushed and ground, and a rare earth-rich perovskite concentrate is obtained by flotation, which contains TiO2 27.3%, REO 36.1%, CaO 32.5% by weight, and the remainder is impurities.

[0056] Example 2

[0057] (1) Using a co-existing ore containing niobium, titanium, rare earth and iron as the main raw material, the co-existing ore has an iron grade of 44.4% T.Fe and contains 53.0% Nb2O, 5.82% TiO2, 2.9% REO, 7.2% SiO2, 2.8% CaO and 2.0% F by weight. Limestone and quartz are added as modifiers, and silicon carbide is added as a reducing agent. High-temperature smelting and reduction are carried out in a submerged arc furnace at a smelting temperature of 1350°C and a smelting time of 20 minutes. During the smelting process, the CaO / SiO2 weight ratio in the slag is controlled to be 1.5, and niobium oxide and iron oxide in the co-existing ore are selectively reduced, thereby achieving separation of niobium and iron from rare earth and titanium. A ferro-niobium alloy melt and a slag containing rare earth and titanium are obtained by smelting. The ferro-niobium alloy melt and the slag are separated by density differences.

[0058] (2) Casting a ferroniobium alloy melt, wherein the ferroniobium alloy contains 91.2% of Fe, 4.3% of Nb, 2.7% of Si, and 0.1% of Ti according to weight percentage.

[0059] (3) The slag is cooled to 1150°C, kept at this temperature for 180 minutes, and then naturally cooled to room temperature. The rare earth and titanium in the slag precipitate and grow directionally in the perovskite phase.

[0060] (4) The cooled slag is crushed and ground, and a rare earth-rich perovskite concentrate is obtained by flotation, which contains TiO2 32.7%, REO 31.9%, CaO 30.2% by weight, and the remainder is impurities.

[0061] Example 3

[0062] (1) Using metallurgical slag containing niobium, titanium, rare earths, and iron as the main raw material, the slag has an iron grade of 7.2% T.Fe, and contains 59.7% Nb2O, 13.5% TiO2, 10.4% REO, 27.2% SiO2, 13.6% CaO, and 8.6% F by weight. Dolomite and quartz are added as modifiers, and a silicon-calcium alloy is added as a reducing agent. High-temperature smelting and reduction are carried out in an electric arc furnace at a smelting temperature of 1300°C and a smelting time of 30 minutes. During the smelting process, the CaO / SiO2 weight ratio in the slag is controlled to be 0.9, and niobium oxide and iron oxide in the co-existing ores are selectively reduced, thereby achieving separation of niobium, iron, rare earths, and titanium. The smelting produces a ferroniobium alloy melt and a slag containing rare earths and titanium. The ferroniobium alloy and the slag are separated by density differences.

[0063] (2) Casting a ferroniobium alloy melt, wherein the ferroniobium alloy contains 46.6% Fe, 47.8% Nb, 3.3% Si, and 0.7% Ti by weight.

[0064] (3) The slag is cooled to 1100°C, kept at this temperature for 120 minutes, and then naturally cooled to room temperature. The rare earth and titanium in the slag precipitate and grow directionally in the perovskite phase.

[0065] (4) The cooled slag is crushed and ground, and a rare earth-rich perovskite concentrate is obtained by flotation, which contains TiO2 33.8%, REO 34.6%, CaO 28.4% by weight, and the remainder is impurities.

[0066] The above examples demonstrate that the method of the present invention can produce high-grade ferroniobium alloy and high-grade rare earth-containing perovskite concentrate. The perovskite concentrate primarily consists of TiO2 and REO, each accounting for approximately one-third, with the remainder being CaO, which facilitates subsequent applications of the perovskite concentrate.

[0067] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for smelting ferroniobium and enriching rare earth and titanium, characterized in that: include: S1. Provide associated ores or metallurgical slag containing niobium, titanium, rare earth and iron; S2, adding a modifier and a siliceous reducing agent, and performing high-temperature smelting and reduction to obtain a layered ferroniobium alloy melt and a slag containing rare earth and titanium; S3, separating the rare earth and titanium-containing slag and cooling it to room temperature under controlled temperature, so that the rare earth and titanium in the slag are directionally precipitated and grown in the perovskite phase; the temperature-controlled cooling method is: first cooling to 1000-1300° C. and keeping the temperature for more than 60 minutes, and then naturally cooling to room temperature; S4, crushing and grinding the cooled slag to obtain rare earth-rich perovskite concentrate by flotation; In S1, the co-existing ore or metallurgical slag containing niobium, titanium, rare earth and iron has an iron grade T.Fe of 0-55%, and contains, by weight, Nb2O5 1-15%, TiO2 1-15%, REO 1-15%, SiO2 5%-30%, CaO 2%-20% and F 2-15%; In S2, the modifier is one or more of dolomite, limestone and quartz; the siliceous reducing agent is one or more of ferrosilicon alloy, ferrosilicon aluminum alloy, calcium silicon alloy and silicon carbide.

2. The method for smelting ferroniobium and enriching rare earth and titanium according to claim 1, characterized in that: The CaO / SiO2 weight ratio in the slag is 0.9-2.

3.

3. The method for smelting ferroniobium and enriching rare earth and titanium according to claim 1, characterized in that: In S2, the high-temperature smelting reduction is carried out in a submerged arc furnace or an electric arc furnace, the smelting temperature is 1200°C-1500°C, and the smelting time is ≥10 min.

4. The method for smelting ferroniobium and enriching rare earth and titanium according to claim 1, characterized in that: The method also includes casting the ferroniobium alloy melt into a mold.

5. The method for smelting ferroniobium and enriching rare earth and titanium according to claim 1, characterized in that: The ferroniobium alloy melt contains Fe 40-95%, Nb 3-55%, Si≤5%, and Ti≤1% by weight.

6. The method for smelting ferroniobium and enriching rare earth and titanium according to claim 1, characterized in that: In S4, the rare earth-rich perovskite concentrate contains TiO2 25%-40%, REO 30-45%, CaO 25-40% by weight, and the remainder is impurities.

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