Baiyuneboite tailing ore phase reconstruction and efficient separation method

Abstract

The invention relates to the technical field of mineral processing, in particular to a Bayan obo tailing ore phase reconstruction and efficient separation method which comprises the following steps: heating raw ore, and introducing hydrogen-based gas for hydrogen-based pre-reduction to obtain a reduction product; adding a modifier into the reduction product, carrying out high-temperature melting modification and heat preservation to obtain molten slag and molten iron, and separating the molten iron to obtain modified slag; cooling the modified slag under the condition of a preset cooling rate, preserving heat, and performing water quenching treatment to obtain a slag sample; and crushing and grinding the slag sample, and carrying out flotation treatment to obtain flotation perovskite containing niobium and rare earth and flotation tailings. A clean and environment-friendly hydrogen group is used as a reducing agent for pre-reduction, and the method has huge environmental benefits. The high-temperature melting state at the last stage of melting modification provides favorable conditions for ore phase reconstruction, and the ore phase reconstruction process does not need to roast or re-melt a treated object, so that high energy consumption caused by secondary heating is avoided, the process is shortened, and the energy consumption is reduced.

Description

Technical Field

[0001] The invention relates to the technical field of mineral processing, and in particular to a method for reconstructing and efficiently sorting the ore phase of Bayan Obo tailings. Background Art

[0003] Niobium, rare earth, iron, titanium and other elements coexist in the Bayan Obo tailings, and due to the low grade of the minerals, fine embedded particle size, and inter-phase mineralization, the selectivity of the valuable components is small, making separation and extraction difficult. For example, patent CN115090411A Baosteel completes the niobium ore selection requirements through four flotation processes, step-by-step dosing and combined selection, and increases the grade of niobium concentrate to more than 4%, but the iron content in the niobium concentrate is still relatively high. In view of the high iron content of tailings, Beijing University of Science and Technology and Northeastern University use a combination of selective reduction and magnetic separation to achieve the reduction and extraction of iron and the initial enrichment of rare earths and niobium in the tailings.

[0004] It should be noted that the valuable elements in the magnetic separation tailings are still dispersed in mineral phases such as calcite ((Ce, Nd)(Ti.Nb), pyrochlore ((Ca, Na, Ce)2(Nb, Ti, Ta)2O6(F, OH)), and ferroniobium rutile ((Fe, Ti, Nb)O2). The grades of rare earth and niobium in the smelted slag obtained by the process of "selective pre-reduction-electric furnace smelting-electric furnace smelting niobium-titanium-iron alloy" are far from reaching the level of industrial-grade rare earth concentrate and niobium concentrate, which greatly limits the quality of subsequent products and their application areas. . The extraction and utilization of rare earths and niobium have always been troubled by the poor, fine, mixed and scattered mineral phase characteristics. In addition, in the selective pre-reduction process, carbonaceous reducing agents are often used to reduce metal elements. However, carbon is prone to reduction reactions with oxides of elements such as niobium and titanium in the slag under high temperature conditions to form niobium carbides. This process causes the viscosity of the slag to increase significantly, accompanied by severe foaming, which makes the separation of slag and iron extremely difficult and may even cause furnace charge splashing accidents. At the same time, the carbon thermal reduction process produces large amounts of carbon dioxide emissions. Summary of the invention

[0005] 1. Technical issues to be resolved In view of the existing technology, the grades of rare earth and niobium in the smelted slag obtained by the process of "selective pre-reduction-electric furnace smelting-electric furnace smelting of niobium-titanium-iron alloy" are far from the level of industrial-grade rare earth concentrate and niobium concentrate, which greatly limits the quality of subsequent products and technical problems in their application fields.

[0006] (II) Technical solution To this end, the present invention discloses a method for reconstructing and efficiently separating the tailings of Bayan Obo, comprising: Step 1: heating the raw ore to a first preset temperature and introducing hydrogen radicals for hydrogen radical pre-reduction, and obtaining a reduction product after reduction for a first preset time; Step 2: adding a modifier to the reduced product, heating it to a second preset temperature and then performing melting modification, keeping it warm for a second preset time to obtain molten slag and molten iron, separating the molten iron to obtain modified slag; Step 3: cooling the modified slag in the high-temperature molten state obtained in step 2 to a third preset temperature under a preset cooling rate condition, keeping the temperature for a third preset time, and performing water quenching to obtain a slag sample; Step 4: The slag sample obtained in step 3 is crushed and ground, and then subjected to flotation treatment to obtain flotation perovskite containing niobium and rare earth and flotation tailings.

[0007] Further, in step 1, based on the sum of the mass percentages as 100%, the components of the raw ore include: T.Fe: 0-50%, Nb2O5: 1-10%, TiO2: 1-20%, REO: 1-25%, SiO2: 5-40%, CaO: 2-20%, F: 2-20%, and the remainder is unavoidable impurities.

[0008] Furthermore, in step 1, the raw material ore is ground to a particle size of less than or equal to 200 mesh, and the amount of the ore accounts for 80-90wt% of the total ore.

[0009] Furthermore, in step 1, the raw ore is placed in a high temperature furnace for heating, and the high temperature furnace includes at least one of a plasma melting furnace, a high temperature tubular dripping furnace, a hydrogen-based vertical furnace, a blast furnace, a rotary kiln, and a fluidized bed.

[0010] Further, in step 1, the first preset temperature is 750-1200° C., the first preset time for hydrogen radical pre-reduction is 30-150 min, and the flow rate of hydrogen radical is 300-1500 mL / min.

[0011] Further, in step 1, the hydrogen base includes one or more of hydrogen, coke oven gas, cracked natural gas, and coal gas reforming gas.

[0012] Further, in step 2, the modifier includes at least one of lime, dolomite, limestone, quartz sand, and quartz stone.

[0013] Further, in step 2, the second preset temperature is 1300-1600° C., and the second preset time is 5-60 min.

[0014] Further, in step 3, the preset cooling rate is 0.1-5°C / min, the third preset temperature is 1300-1100°C, and the third preset time is greater than or equal to 30 minutes.

[0015] Furthermore, in the flotation treatment, the slag sample is ground to a particle size of 200-300 mesh, the collector is one of oleic acid, hydroxamic acid, dodecylamine dimethylphosphonic acid, and octyl isohydroxamic acid, the inhibitor is one of sodium fluorosilicate and water glass, and the adjuster is one of sulfuric acid and sodium hydroxide.

[0016] (III) Beneficial effects The beneficial effect of the present invention is as follows: the present invention provides a method for phase reconstruction and efficient sorting of Bayan Obo tailings, comprising: heating the raw ore to a first preset temperature, introducing hydrogen radicals for hydrogen radical pre-reduction to obtain a reduction product; adding a modifier to the reduction product, heating it to a second preset temperature, performing melting modification, keeping it warm for a second preset time to obtain slag and molten iron, separating the molten iron to obtain modified slag; cooling the obtained modified slag in a high-temperature molten state to a third preset temperature under a preset cooling rate, keeping it warm for a third preset time, and performing water quenching to obtain a slag sample; crushing and grinding the obtained slag sample, and then performing flotation treatment to obtain flotation perovskite containing niobium and rare earth and flotation tailings.

[0017] This application uses hydrogen as a clean and environmentally friendly emerging strategic energy source, which can effectively avoid the formation of carbides and foaming. Therefore, this method uses hydrogen as a reducing agent for selective pre-reduction. In the melting and reforming stage, a reforming agent is added to the Bayan Obo tailings for melting and reforming to improve the viscosity and fluidity of the slag and promote the separation of slag and iron. 2+ Occupies the A site, Ti 4+ Occupies the B site, when niobium and rare earth enter the perovskite, Nb 5+ Will occupy part of Ti 4+ site, rare earth occupies part of Ca 2+ Position, so the perovskite can accommodate different amounts of niobium and rare earth oxides. Therefore, by controlling the temperature of the high-temperature molten state of the slag at the end of the molten reforming process, the directional crystallization of niobium and rare earth in the tailings can be achieved, and a single, coarse perovskite containing niobium and rare earth can be obtained. Finally, through flotation, the grade of niobium and rare earth is increased to more than 4 times that of the original ore. This mineral phase reconstruction method does not require roasting or remelting of the treatment object, thereby avoiding the high energy consumption caused by secondary heating. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 A schematic flow chart of a method for phase reconstruction and efficient separation of Bayan Obo tailings mentioned in this application; Figure 2 This is a process flow chart of a method for phase reconstruction and efficient sorting of Bayan Obo tailings mentioned in this application. DETAILED DESCRIPTION

[0019] In order to better explain the present invention and facilitate understanding, the present invention is described in detail below through specific implementation modes in conjunction with the accompanying drawings.

[0020] When amount, concentration or other value or parameter is represented by range, preferred range or a series of upper preferred value and lower preferred value, this should be understood as specifically disclosing all ranges formed by any pairing of any range upper limit or preferred value and any range lower limit or preferred value, regardless of whether the range is disclosed separately. For example, when disclosing range "1-5", described range should be interpreted as including range "1-4", "1-3", "1-2", "1-2 and 4-5", "1-3 and 5" etc. When numerical range is described in this article, unless otherwise stated, the range is intended to include its end value and all integers and fractions within the range.

[0021] In these embodiments, unless otherwise specified, the parts and percentages are all by mass. "Parts by mass" refers to the basic unit of measurement representing the mass ratio of multiple components, and 1 part can represent any unit mass, such as 1 g, or 3.527 g, etc. If we say that the mass of component A is a part and the mass of component B is b parts, it means the ratio of the mass of component A to the mass of component B a:b. Alternatively, it means that the mass of component A is aK and the mass of component B is bK (K is an arbitrary number, indicating a multiple factor). It should not be misunderstood that, unlike the mass parts, the sum of the mass parts of all components is not limited to 100 parts. "And / or" is used to indicate that one or both of the situations described may occur, for example, A and / or B include (A and B) and (A or B).

[0022] refer to Figure 1 and Figure 2 This application mentions a method for phase reconstruction and efficient separation of Bayan Obo tailings, including: Step 1: After heating the raw ore to a first preset temperature, hydrogen radicals are introduced for hydrogen radical pre-reduction, and a reduction product is obtained after a first preset time.

[0023] This application selects Bayan Obo tailings as the raw material ore. Taking the sum of mass percentage as 100%, the composition of the raw material ore includes: T.Fe: 0-50%, Nb2O5: 1-10%, TiO2: 1-20%, REO: 1-25%, SiO2: 5-40%, CaO: 2-20%, F: 2-20%, and the remainder is inevitable impurities. By clarifying the content range of key components such as T.Fe (Total Iron), Nb2O5, TiO2, REO (Rare Earth Oxides) in the raw materials, it is conducive to the targeted selection of appropriate reduction conditions and subsequent processing steps. For example, for high-content niobium and rare earth, the reduction temperature, reduction time, cooling rate and other conditions can be optimized to improve their recovery rate.

[0024] It should be noted that heating the raw ore to a certain temperature can increase the reactivity of the ore. And one or more of hydrogen, coke oven gas, cracked natural gas, and coal gas reforming gas are used for reduction reaction. There are multiple hydrogen-based sources including hydrogen, coke oven gas, cracked natural gas, and coal gas reforming gas. The most economical and environmentally friendly reducing agent can be selected according to actual conditions.

[0025] In the present technical scheme, in step 1, the raw material ore is ground to a particle size of less than or equal to 200 mesh, and the amount of the ore accounts for 80-90wt% of the total amount of the ore. Grinding the raw material ore to a particle size of less than or equal to 200 mesh, and the amount of the ore accounts for 80-90wt% of the total amount of the ore, can increase the specific surface area of ​​the mineral, increase the contact area with the hydrogen-based reducing agent, thereby accelerating the reduction reaction, shortening the reduction time, and improving production efficiency. The fine-grained raw material ore is easier to achieve uniform reaction during the heating and reduction process, reducing the local unreacted area, and improving the quality and consistency of the reduction product. The fine-grained ore is easier to fully mix with the modifier and flotation agent in the subsequent high-temperature melting modification, flotation and other steps, thereby improving the treatment effect.

[0026] In the present technical solution, in step 1, the raw ore is placed in a high-temperature furnace for heating, and the high-temperature furnace includes at least one of a plasma smelting furnace, a high-temperature tubular dripping furnace, a hydrogen-based vertical furnace, a blast furnace, a rotary kiln, and a fluidized bed. The present application can select a suitable high-temperature furnace according to actual production conditions and needs. The plasma smelting furnace has the characteristics of high temperature and high energy density, and is suitable for processing refractory minerals; the hydrogen-based vertical furnace is suitable for large-scale continuous production; the rotary kiln and the fluidized bed have good heat and mass transfer properties, and are suitable for specific reduction reactions. For raw ores of different compositions and properties, the most suitable high-temperature furnace can be selected for heating and reduction to improve the adaptability and reliability of the process.

[0027] In the technical solution, in step 1, the first preset temperature is 750-1200°C, the reduction time of the hydrogen-based pre-reduction is the first preset time, the first preset time is 30-150min, and the flow rate of the hydrogen-based is 300-1500mL / min.

[0028] In the present application, the first preset temperature is the reduction temperature, the temperature range of 750-1200°C. Within the first preset temperature range, the hydrogen-based reducing agent has a high activity and can effectively reduce the metal oxide to a metal or a low-valent oxide. The reduction time of 0-150min can ensure that the reaction is fully carried out and improve the quality of the reduced product. The hydrogen-based flow rate of 300-1500mL / min can ensure the smooth progress of the reduction reaction while avoiding the waste of hydrogen and safety risks. By controlling the hydrogen-based flow rate, the speed of the reduction reaction can be adjusted, and the reduction time and temperature are coordinated to achieve efficient production.

[0029] Step 2: adding a modifier to the reduced product, heating it to a second preset temperature and then performing melting modification, keeping it warm for a second preset time to obtain molten slag and molten iron, separating the molten iron to obtain modified slag; In the technical solution, in step 2, the modifier includes at least one of lime, dolomite, limestone, quartz sand and quartz stone. Adding the modifier can adjust the physical and chemical properties of the slag, making it more conducive to subsequent separation and treatment.

[0030] In the technical solution, in step 2, the melting temperature of the high temperature melting reforming, that is, the second preset temperature is 1300-1600°C, and the second preset time is 5-60 minutes. Under the 5-60 minutes of holding time, the reaction can be more fully carried out, so that the slag and molten iron can be better separated.

[0031] The present application can reduce the viscosity of the slag through the action of the modifier, making it easier to separate the molten iron and improving the iron recovery rate.

[0032] Step 3: Cool the modified slag in the high-temperature molten state obtained in step 2 to a third preset temperature under a preset cooling rate condition, keep the temperature for a third preset time, and perform water quenching to obtain a slag sample.

[0033] In the technical solution, in step 3, the preset cooling rate is 0.1-5°C / min, the third preset temperature is 1300-1100°C, and the third preset time is greater than or equal to 30 minutes.

[0034] The present application controls the cooling rate to allow the minerals in the slag to crystallize and undergo phase changes under specific temperature conditions, thereby forming a specific mineral phase structure. Insulation for greater than or equal to 30 minutes can make these crystallization and phase change processes more complete. Specifically, the present application crystallizes the slag in a high-temperature molten state at a certain cooling rate. Different phases will precipitate during this process, and the precipitated phases will be quickly cooled by water quenching to retain the precipitated phases. Exemplarily, the slag in a molten state at 1600°C is cooled to 1100°C at a cooling rate of 1°C / min, wherein perovskite is precipitated. The slag is quickly cooled by water quenching to fix the perovskite phase at 1100°C.

[0035] Step 4: The slag sample obtained in step 3 is crushed and ground, and then subjected to flotation treatment to obtain flotation perovskite containing niobium and rare earth and flotation tailings.

[0036] In the present technical scheme, during the flotation treatment, the slag sample is ground to a particle size of 200-300 mesh, the collector is one of oleic acid, hydroxamic acid, dodecylamine dimethylphosphonic acid, and octyl isohydroxamic acid, the inhibitor is one of sodium fluorosilicate and water glass, the adjuster is one of sulfuric acid and sodium hydroxide, and the foaming agent is 2# oil.

[0037] Crushing and grinding can refine the slag sample, increase the specific surface area of ​​the mineral, and improve the efficiency of flotation. The present application obtains high-grade perovskite containing niobium and rare earth through flotation treatment, providing high-quality raw materials for subsequent further processing and utilization. The minerals containing niobium and rare earth are effectively separated to improve the recovery rate of niobium and rare earth.

[0038] The present invention proposes a method for phase reconstruction and efficient separation of Bayan Obo tailings. The method utilizes hydrogen as a clean and environmentally friendly emerging strategic energy source, which can effectively avoid the formation of carbides and foaming. Therefore, the method uses hydrogen as a reducing agent for selective pre-reduction. In the melting and modification stage, a modifier is added to melt-modify the Bayan Obo tailings to improve the viscosity and fluidity of the slag and promote the separation of slag and iron. At the same time, by controlling the temperature using the high-temperature molten state of the slag at the end of the melting and modification, directional crystallization of niobium and rare earths in the tailings can be achieved to obtain cerium niobium perovskite. Finally, through flotation, the grade of niobium and rare earths is increased to more than 4 times that of the original ore. The method for phase reconstruction does not require roasting or remelting the treatment object, thereby avoiding high energy consumption caused by secondary heating.

[0039] The present invention uses clean and environmentally friendly hydrogen as a reducing agent for pre-reduction, which avoids the generation of carbides and foaming, can achieve a substantial reduction in CO2 emissions during the reduction process, and has huge environmental benefits. While successfully recovering rare metals, efficient recovery of iron can also be achieved. The high-temperature molten state at the end of the molten reforming provides favorable conditions for mineral phase reconstruction. The mineral phase reconstruction process does not require roasting or remelting of the treatment object, avoids high energy consumption caused by secondary heating, shortens the process, and saves energy. Utilizing the easy flotation characteristics of the perovskite-type mineral phase, a physical mineral processing (flotation) method is used to obtain a high-value-added high-niobium grade perovskite-type mineral phase that can be used to prepare niobium-titanium alloys, niobium-titanium composite ceramic materials, etc., effectively recovering rare metal resources and having huge economic benefits.

[0040] In order to better understand the technical solution, 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 set forth herein. On the contrary, 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.

[0041] Example 1 Step 1: Place the Bayan Obo tailings in a hydrogen-based vertical furnace, heat it to 1000°C, introduce hydrogen and keep it warm for 90 minutes for hydrogen pre-reduction, wherein the composition of the Bayan Obo tailings is T.Fe 35%, Nb2O5 2%, TiO2 7%, REO 10%, SiO235%, CaO 6%, and F 5%.

[0042] Step 2: Add the modifier CaO to the reduction product in step 1, adjust the basicity to 0.5, place it in a crucible and heat it to 1500°C to fully melt the material, keep it warm for 30 minutes to completely separate the slag from the metal, pour out the molten iron, and obtain modified slag.

[0043] Step 3: Cool the modified slag in the high-temperature molten state in step 2 to 1300°C at a cooling rate of 1°C / min, keep it warm for 4 hours, and then perform water quenching.

[0044] Step 4: After crushing and grinding the slag sample obtained in step 3, flotation treatment is performed, the pH value is adjusted to 6.0, and 500 g / t of hydroxamic acid, 100 g / t of water glass and 60 g / t of 2# oil are used.

[0045] After analysis, the above steps can obtain Nb2O5 content of 14%, CeO2 content of 45%, TiO2 content of 29%, and the rest are impurities.

[0046] Example 2 Step 1: Place the Bayan Obo tailings in a hydrogen-based vertical furnace, heat it to 1100°C, introduce hydrogen and keep it warm for 150 minutes for hydrogen reduction, wherein the composition of the Bayan Obo tailings is T.Fe 45%, Nb2O5 1%, TiO2 6%, REO 15%, SiO2 28%, CaO 2%, and F 3%.

[0047] Step 2: Add the modifier CaO to the reduction product in step 1, adjust the basicity to 1.0, place it in a crucible and heat it to 1600°C to fully melt the material, keep it warm for 60 minutes to completely separate the slag from the metal, pour out the molten iron, and obtain modified slag.

[0048] Step 3: Cool the modified slag in the high-temperature molten state in step 2 to 1100°C at a cooling rate of 5°C / min, keep it warm for 10 hours, and then quench it with water.

[0049] Step 4: After crushing and grinding the slag sample obtained in step 3, flotation treatment is performed, the pH value is adjusted to 10.5, and 600 g / t of oleic acid, 150 g / t of water glass and 50 g / t of 2# oil are used.

[0050] After analysis, the above steps can obtain Nb2O5 content of 13%, CeO2 content of 46%, TiO2 content of 35%, and the rest are impurities.

[0051] Example 3 Step 1: Place the Bayan Obo tailings in a fluidized bed, heat it to 1100°C, introduce hydrogen and keep it warm for 120 minutes for hydrogen reduction, wherein the composition of the Bayan Obo tailings is T.Fe 25%, Nb2O5 5%, TiO2 12%, REO 22%, SiO2 31%, CaO 4%, and F 1%.

[0052] Step 2: Add the modifier CaO to the reduction product in step 1, adjust the basicity to 1.5, place it in a crucible and heat it to 1600°C under the protection of inert gas to fully melt the material, and keep it warm for 60 minutes to completely separate the slag and the metal.

[0053] Step 3: Cool the high-temperature molten material in step 2 to 1100°C at a cooling rate of 3°C / min, keep it warm for 16 hours, and then quench it with water.

[0054] Step 4: After crushing and grinding the slag sample obtained in step 3, flotation treatment is performed, the pH value is adjusted to 10.5, and 200 g / t of octyl hydroxamic acid, 100 g / t of water glass, and 70 g / t of 2# oil are used.

[0055] After analysis, the above steps can obtain Nb2O5 content of 17%, CeO2 content of 43%, TiO2 content of 37%, and the rest are impurities.

[0056] The above describes the basic principles, main features and advantages of the present invention. However, the above is only a specific embodiment of the present invention, and the technical features of the present invention are not limited thereto. Any other implementation methods derived by any technician in the field without departing from the technical solution of the present invention should be included in the patent scope of the present invention.

[0057] In the description of the present invention, each embodiment focuses on the differences from other embodiments, and the same or similar parts between the embodiments can be referred to each other. For the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the method part description.

[0058] In the description of the present invention, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply that there is any such actual relationship or order between these entities or operations. In the description of the present invention, the meaning of "multiple" is two or more, unless otherwise clearly and specifically limited. Moreover, the term "includes", "comprising" or any other variant thereof is intended to cover non-exclusive inclusion, so that the process, method, article or equipment including a series of elements not only includes those elements, but also includes other elements not clearly listed, or also includes elements inherent to such process, method, article or equipment. In the absence of more restrictions, the elements limited by the sentence "comprising one..." do not exclude the existence of other identical elements in the process, method, article or equipment including the elements.

[0059] In the present invention, unless otherwise clearly specified and limited, when a first feature is “on” or “below” a second feature, it may be that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediate medium. Moreover, when a first feature is “above”, “above” or “above” a second feature, it may be that the first feature is directly above or obliquely above the second feature, or it may simply mean that the first feature is higher in level than the second feature. When a first feature is “below”, “below” or “below” a second feature, it may be that the first feature is directly below or obliquely below the second feature, or it may simply mean that the first feature is lower in level than the second feature.

[0060] In the description of this specification, the description of the terms "one embodiment", "some embodiments", "embodiment", "example", "specific example" or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, unless they are contradictory.

[0061] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may alter, modify, replace and modify the above embodiments within the scope of the present invention.

Claims

1. A method for reconstructing and efficiently separating the tailings of Bayan Obo, characterized in that: include: Step 1: heating the raw ore to a first preset temperature and then introducing a hydrogen-based gas for hydrogen-based pre-reduction, and obtaining a reduction product after reduction for a first preset time; Step 2: adding a modifier to the reduction product, heating it to a second preset temperature and then performing melting modification, keeping the temperature for a second preset time to obtain slag and molten iron, separating the molten iron, and obtaining modified slag; Step 3: cooling the modified slag in the high-temperature molten state obtained in step 2 to a third preset temperature under a preset cooling rate condition, keeping the temperature for a third preset time, and performing water quenching to obtain a slag sample; Step 4: The slag sample obtained in step 3 is crushed and ground, and then subjected to flotation treatment to obtain flotation perovskite containing niobium and rare earth and flotation tailings.

2. The method for phase reconstruction and efficient separation of Bayan Obo tailings according to claim 1, characterized in that: In step 1, taking the sum of the mass percentages as 100%, the components of the raw ore include: T.Fe: 0-50%, Nb2O5: 1-10%, TiO2: 1-20%, REO: 1-25%, SiO2: 5-40%, CaO: 2-20%, F: 2-20%, and the remainder is unavoidable impurities.

3. The method for phase reconstruction and efficient separation of Bayan Obo tailings according to claim 1, characterized in that: In step 1, the raw ore is ground to a particle size of less than or equal to 200 mesh, and the amount of the ore accounts for 80-90wt% of the total ore.

4. The method for phase reconstruction and efficient separation of Bayan Obo tailings according to claim 1, characterized in that: In step 1, the raw ore is placed in a high temperature furnace for heating, wherein the high temperature furnace includes at least one of a plasma melting furnace, a high temperature tubular dripping furnace, a hydrogen-based vertical furnace, a blast furnace, a rotary kiln, and a fluidized bed.

5. The method for phase reconstruction and efficient separation of Bayan Obo tailings according to claim 1, characterized in that: In step 1, the first preset temperature is 750-1200° C., the first preset time for hydrogen radical pre-reduction is 30-150 min, and the flow rate of hydrogen radical is 300-1500 mL / min.

6. The method for phase reconstruction and efficient separation of Bayan Obo tailings according to claim 1, characterized in that: In step 1, the hydrogen radical includes one or more of hydrogen, coke oven gas, cracked natural gas, and coal gas reforming gas.

7. The method for phase reconstruction and efficient separation of Bayan Obo tailings according to claim 1, characterized in that: In step 2, the modifier includes at least one of lime, dolomite, limestone, quartz sand and quartz stone.

8. The method for phase reconstruction and efficient separation of Bayan Obo tailings according to claim 1, characterized in that: In step 2, the second preset temperature is 1300-1600° C., and the second preset time is 5-60 min.

9. The method for phase reconstruction and efficient separation of Bayan Obo tailings according to claim 1, characterized in that: In step 3, the preset cooling rate is 0.1-5°C / min, the third preset temperature is 1300-1100°C, and the third preset time is greater than or equal to 30 minutes.

10. The method for phase reconstruction and efficient separation of Bayan Obo tailings according to claim 1, characterized in that: In the flotation treatment, the slag sample is ground to a particle size of 200-300 meshes, the collector is one of oleic acid, hydroxamic acid, dodecylamine dimethylphosphonic acid, octyl isohydroxamic acid, the inhibitor is one of sodium fluorosilicate and water glass, and the adjuster is one of sulfuric acid and sodium hydroxide.

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