An additive composition for separating niobium and iron in niobium iron ore and its application

Abstract

The application discloses an additive composition for separating niobium and iron in niobium iron ore and application thereof, and belongs to the technical field of metallurgy and mineral processing. The additive composition comprises, in terms of weight fractions, 45-70 parts of calcium oxide, 15-40 parts of silicon oxide and 5-10 parts of fluoride. In addition, the application also provides application of the additive composition in treatment of niobium iron ore. The additive composition can realize efficient separation of niobium and iron in low-grade niobium iron ore under the joint action of the components.

Description

Technical Field

[0001] This invention relates to the fields of metallurgy and mineral processing, specifically to an additive composition for separating niobium iron from niobium iron ore and its application. Background Technology

[0002] Niobium is an important strategic metal, widely used in steel, aerospace, and electronics industries. The Bayan Obo iron-niobium-rare earth polymetallic mine is my country's largest niobium resource base. However, due to the diverse and complex composition of its niobium-bearing minerals, including a high proportion of low-niobium minerals (niobium-iron rutile, calcite) and a low content of low-iron, high-niobium minerals (niobium-calcium ore, pyrochlore), as well as their fine grain size (mostly less than 20 μm) and close association with other minerals, conventional beneficiation processes can only yield niobium rough concentrate with an Nb₂O₅ grade below 5%, making it impossible to directly obtain high-grade (50%–60% Nb₂O₅) niobium concentrates similar to those from Brazil.

[0003] Direct smelting of low-grade niobium concentrate cannot produce high-grade ferroniobium, and may not even meet the quality requirements of medium-grade ferroniobium.

[0004] Chinese patent ZL201710206924.0 discloses a method for separating niobium from iron using titanium-niobium iron ore powder, carbonaceous reducing agent, CaCO3, additives, and binder as raw materials. The process involves batching, mixing, pelletizing, direct reduction, and smelting. The smelting process is carried out at a temperature of 1350–1400℃, and the pellets are completely melted. Therefore, slow cooling and crystallization are necessary to achieve niobium mineral crystal growth for subsequent flotation. The crystal size can reach 20–50 μm. After magnetic separation, pig iron and 5%–12% niobium-rich slag are obtained. The niobium-rich slag is then finely ground and flotated to obtain niobium-rich slag concentrate with an Nb2O5 content of 15%–40%. However, the slag after slow crystallization contains niobium / iron ore phases dispersed in the perovskite, forming a perovskite-titanium-iron-niobium symbiotic mineral. Theoretically, this symbiotic mineral phase has a low Nb2O5 content, making it difficult to obtain qualified niobium concentrate through processing. Secondly, the crystal size of niobium minerals is difficult to control. Niobium-rich slag must be ground to below 30 μm, and after recrystallization, niobium minerals are tightly bound to gangue minerals. The sorting process introduces a large amount of gangue minerals, thus limiting the improvement of niobium concentrate grade. Moreover, the energy consumption of the pelletizing and melting process is high, which is not conducive to industrial application.

[0005] Therefore, low-grade niobium-iron ore cannot be directly processed by flotation. More importantly, the separation of niobium and iron in the raw ore is a crucial issue. When the iron content in the mineral is reduced to a certain level, the influence of iron in the separation process is decreased, which is more conducive to improving the efficiency of subsequent separation processes. However, how to achieve effective separation of niobium and iron in low-grade niobium-iron ore is a problem that existing technologies need to solve. Summary of the Invention

[0006] The purpose of this invention is to overcome the above-mentioned technical deficiencies and provide an additive composition for separating niobium from niobium ore and its application, thereby solving the technical problem of how to achieve the separation of niobium from low-grade niobium ore in the prior art.

[0007] To achieve the above-mentioned technical objectives, the present invention provides an additive composition for separating niobium iron from niobium iron ore, comprising, by weight, 45-70 parts of calcium oxide, 15-40 parts of silicon oxide, and 5-10 parts of fluoride.

[0008] In some embodiments, the fluoride is one or more of magnesium fluoride, calcium fluoride, and barium fluoride.

[0009] In some embodiments, the fluoride is a mixture of magnesium fluoride, calcium fluoride and barium fluoride; wherein the mass ratio of magnesium fluoride, calcium fluoride and barium fluoride is 1:(1-1.5):(2-3).

[0010] In addition, the present invention also proposes the application of the above-mentioned additive composition for separating niobium iron from niobium iron ore in the treatment of niobium iron ore.

[0011] In some embodiments, the above application includes: mixing a composition of niobite, a reducing agent, and an additive, then adding a binder, then pressing it into a block, then drying it, then placing the dried block into a container, and then smelting it at 1150-1300°C under the protection of an inert gas.

[0012] In some embodiments, the mass ratio of the columbite to the reducing agent is 100:(18-22); and / or, the mass ratio of the columbite to the additive is 100:(35-45).

[0013] In some embodiments, the melting time at 1150-1300°C is 100 minutes or more.

[0014] In some embodiments, the reducing agent is one or more of activated carbon, oil coke, pulverized coal, coke, and heavy oil.

[0015] In some embodiments, the adhesive is a solution of one or more of PVA, water glass, and clay.

[0016] In some embodiments, the mass concentration of the PVA solution is 5%-8%, and the material ratio of the niobium iron ore to the PVA solution is 5 kg:(0.5-0.8) L.

[0017] Compared with the prior art, the beneficial effects of the present invention include: The present invention proposes an additive composition, which, by weight, includes 45-70 parts of calcium oxide, 15-40 parts of silicon oxide, and 5-10 parts of fluoride. The calcium oxide in the additive composition will combine with niobium oxide to form complex oxides, which is beneficial to improving the stability of niobium in slag. At the same time, the calcium component is an indispensable slag-forming agent in smelting. Therefore, the process has a high utilization rate of niobium concentrate and is beneficial to the preparation of low-iron, niobium-rich slag. The silicon oxide and calcium oxide in the additive composition adjust the basicity of niobium iron ore to 3-4, thereby adjusting the melting point of the reaction system. The fluoride in the additive composition can increase the stability of niobium oxide, hinder its participation in the reduction reaction, reduce the proportion of niobium flowing into the metal phase, thereby improving the niobium iron separation effect. Moreover, it can increase the intensity of the reaction and reduce the reaction time. Under the combined action of the components of the additive composition, the efficient separation of niobium iron from low-grade niobium iron ore can be achieved. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the process for processing niobium iron concentrate according to a specific embodiment of the present invention.

[0019] Figure 2 This is a schematic diagram illustrating the principle of processing niobium-iron concentrate according to a specific embodiment of the present invention.

[0020] Figure 3 This is a photograph of niobium-iron ore processed according to Example 1 of the present invention. Detailed Implementation

[0021] This specific embodiment provides an additive composition for separating niobium iron from niobium iron ore, comprising, by weight, 45-70 parts calcium oxide, 15-40 parts silicon oxide, and 5-10 parts fluoride; in some embodiments, the fluoride is one or more of magnesium fluoride, calcium fluoride, and barium fluoride; in some embodiments, the fluoride is magnesium fluoride, calcium fluoride, and barium fluoride; the mass ratio of the magnesium fluoride, calcium fluoride, and barium fluoride is 1:(1-1.5):(2-3).

[0022] Combination Figure 1This specific embodiment also proposes the application of the above-mentioned additive composition for separating niobium iron from niobium iron ore in the treatment of niobium iron ore, including mixing niobium iron ore, reducing agent and additive composition, then adding binder, then pressing into blocks, then drying, then placing the dried blocks into a container, and then smelting at 1150-1300℃ for more than 100 min, preferably 100-120 min, under the protection of inert gas; wherein, the mass ratio of niobium iron ore to reducing agent is 100:(18-22); the mass ratio of niobium iron ore to additive is 100:(35-45); in some embodiments, the reducing agent is one or more of activated carbon, oil coke, coal powder, coke and heavy oil, and the binder is PVA solution (i.e., polyvinyl alcohol solution); the mass concentration of the PVA solution is 5%-8%, and the material ratio of niobium iron ore to PVA solution is 5 kg:(0.5-0.8) L.

[0023] The binder can also be any existing technology, including, but not limited to, one or more solutions of PVA, water glass, clay, etc. Molding can be carried out using existing equipment (including presses, molds, briquetting machines, etc.) and conventional methods, such as briquetting or pelletizing. This invention does not impose any special limitations on the molding pressure; for example, molding can be performed at 15–25 MPa or higher or lower pressures. Molding increases the contact area between the niobium mineral and the reactants, promoting the solid-phase reaction.

[0024] Combination Figure 2 The present invention first obtains a mixture containing niobium crude concentrate, and adjusts the alkalinity and reducing agent content of the niobium crude concentrate. Then, the mixture is placed in an inert protective gas and smelted at a certain temperature, so that the iron element in the niobium crude concentrate is reduced to metallic iron in a reducing atmosphere, and most of the niobium-containing minerals in the niobium crude concentrate enter the slag phase, thus obtaining iron-free niobium-containing crude concentrate.

[0025] The "high-speed iron niobium-bearing ore" mentioned in this invention refers to iron ore containing a small amount of niobium that is in a natural environment, such as the Bayan Obo polymetallic ore.

[0026] The "niobium-iron concentrate" mentioned in this invention refers to the rough concentrate obtained from high-iron niobium-bearing ore through pre-selection, and is used as the raw material of this invention. The niobium-containing minerals in the niobium-iron concentrate are called "niobium-bearing minerals" (or niobium minerals).

[0027] The "iron-removed niobium-containing rough concentrate" mentioned in this invention refers to the niobium rough concentrate slag phase remaining after most of the iron oxides in the niobium rough concentrate are reduced to metallic iron by the method of this invention and then separated.

[0028] The "niobium concentrate" mentioned in this invention refers to the niobium rough concentrate or the iron-removed niobium rough concentrate obtained by this invention, which is then further sorted, for example by flotation, to obtain a high-grade niobium ore product.

[0029] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0030] In this invention, the terms "some embodiments," "this embodiment," "this embodiment," and examples are used to describe a subset of all possible embodiments. However, it is understood that "some embodiments" can be the same subset or different subsets of all possible embodiments and can be combined with each other without conflict.

[0031] If the application documents contain similar descriptions such as "first / second", the following explanation shall be added: In the following description, the terms "first / second / third" are used only to distinguish similar objects and do not represent a specific order of objects. It is understood that "first / second / third" may be interchanged in a specific order or sequence where permitted, so that the embodiments described herein can be implemented in an order other than that illustrated or described herein.

[0032] In this embodiment, the term "and / or" is merely a description of the relationship between related objects, indicating that there can be three relationships. For example, object A and / or object B can represent three situations: object A exists alone, object A and object B exist simultaneously, and object B exists alone.

[0033] In the following examples or comparative examples, niobium-iron concentrate with a niobium grade of 0.87% obtained from the pre-selection of niobium-containing ore was used as the main raw material, and its chemical composition is shown in Table 1.

[0034] Table 1 Chemical composition of raw materials (wt%)

[0035]

[0036] The separation coefficient of niobium and iron is calculated as follows:

[0037]

[0038] In this invention, basicity is defined as the mass ratio of CaO to SiO2. The regulation of basicity is crucial for the enrichment of niobium; too low or too high basicity results in a high melting point of the reaction system, leading to incomplete reaction. This invention primarily controls several factors—basicity, reducing agent content, smelting atmosphere, and smelting temperature—to reduce iron oxides in niobium-iron concentrate to metallic iron, while niobium oxides remain in the slag phase without reduction.

[0039] Example 1

[0040] This embodiment proposes an additive composition for separating niobium iron from niobium iron ore, comprising, by weight, 70 parts calcium oxide, 20 parts silicon oxide, and 8 parts calcium fluoride.

[0041] This embodiment also proposes the application of the above-mentioned additive composition for separating niobium from niobium ore in the treatment of niobium concentrate, including: taking 5 kg of niobium concentrate, adding 0.9 kg of activated carbon as a reducing agent and 2 kg of the additive composition to adjust the alkalinity to 3.5, mixing thoroughly in a ball mill, adding 0.5 L of 5% PVA solution, and molding the mixture using a press and mold to obtain a cylinder (i.e., a type of block) with a diameter of Φ0.5 m. After drying for 12 h, it is placed in a 10 L iron container and smelted at 1300 °C for 100 min under the condition of passing inert protective gas argon. After cooling with the furnace, the slag phase is dissolved with hydrochloric acid and HF acid. ICP analysis results show that the iron content in the slag phase is reduced to 7.01%, the niobium content in the slag phase is 0.49%, and the niobium-iron separation coefficient reaches 4.64. Figure 3 It can be seen that the metallic phase and the slag phase are clearly separated.

[0042] Example 2

[0043] This embodiment proposes an additive composition for separating niobium iron from niobium iron ore, comprising 45 parts calcium oxide, 40 parts silicon oxide, and 5 parts calcium fluoride by weight.

[0044] This embodiment also proposes the application of the above-mentioned additive composition for separating niobium from niobium ore in the treatment of niobium concentrate, including: taking 5 kg of niobium concentrate, adding 1 g of activated carbon as a reducing agent and 2.25 kg of additive composition to adjust the alkalinity to 1.125, mixing thoroughly in a ball mill, adding 0.6 L of 5% PVA solution, and molding the mixture into cylinders with a diameter of Φ0.5 m using a press and mold, drying for 12 h and then placing it in a 10 L iron container, smelting at 1200 °C for 120 min under inert protective gas, cooling with the furnace, dissolving the slag phase with hydrochloric acid and HF acid, and ICP analysis results showing that the iron content in the slag phase decreased to 4.59%, the niobium content in the slag phase was 0.22%, and the niobium-iron separation coefficient reached 3.19.

[0045] Example 3

[0046] This embodiment proposes an additive composition for separating niobium iron from niobium iron ore, comprising, by weight, 60 parts calcium oxide, 30 parts silicon oxide, and 10 parts calcium fluoride.

[0047] This embodiment also proposes the application of the above-mentioned additive composition for separating niobium from niobium ore in the treatment of niobium concentrate, including: taking 5 kg of niobium concentrate, adding 1.1 kg of activated carbon as a reducing agent and 1.75 kg of additive composition to adjust the alkalinity to 2, mixing thoroughly in a ball mill, adding 0.8 L of 5% PVA solution, and molding the mixture into cylinders with a diameter of Φ0.5 m using a press and mold, drying for 12 h and then placing it in a 10 L iron container, smelting at 1100 °C for 110 min under inert protective gas, cooling with the furnace, dissolving the slag phase with hydrochloric acid and HF acid, and ICP analysis results showing that the iron content in the slag phase decreased to 52.67%, the niobium content in the slag phase was 0.58%, and the niobium-iron separation coefficient reached 0.68.

[0048] Example 4

[0049] This embodiment proposes an additive composition for separating niobium iron from niobium iron ore, comprising, by weight, 65 parts calcium oxide, 25 parts silicon oxide, and 7 parts calcium fluoride.

[0050] This embodiment also proposes the application of the above-mentioned additive composition for separating niobium from niobium ore in the treatment of niobium concentrate, including: taking 5 kg of niobium concentrate, adding 0.9 kg of activated carbon as a reducing agent and 1.75 kg of additive composition to adjust the alkalinity to 2.6, mixing thoroughly in a ball mill, adding 0.5 L of 5% PVA solution, and molding the mixture into cylinders with a diameter of Φ0.5 m using a press and mold, drying for 12 h and then placing it in a 10 L iron container, smelting at 1300 °C for 100 min under inert protective gas, cooling with the furnace, dissolving the slag phase with hydrochloric acid and HF acid, and ICP analysis results showing that the iron content in the slag phase decreased to 7.79%, the niobium content in the slag phase was 0.64%, and the niobium-iron separation coefficient reached 5.46.

[0051] Example 5

[0052] This embodiment proposes an additive composition for separating niobium iron from niobium iron ore, comprising, by weight, 70 parts calcium oxide, 20 parts silicon oxide, and 8 parts fluoride; wherein the fluoride is a mixture of magnesium fluoride and calcium fluoride, with a mass ratio of magnesium fluoride to calcium fluoride of 1:1.2.

[0053] This embodiment also proposes the application of the above-mentioned additive composition for separating niobium from niobium ore in the treatment of niobium concentrate, including: taking 5 kg of niobium concentrate, adding 0.9 kg of activated carbon as a reducing agent and 2 kg of additive composition to adjust the alkalinity to 3.5, mixing thoroughly in a ball mill, adding 0.5 L of 5% PVA solution, and molding the mixture into cylinders with a diameter of Φ0.5 m using a press and mold, drying for 12 h and then placing it in a 10 L iron container, melting at 1300 °C for 100 min under the condition of passing inert protective gas argon, cooling with the furnace, dissolving the slag phase with hydrochloric acid and HF acid, and ICP analysis results showing that the iron content in the slag phase decreased to 7.01%, the niobium content in the slag phase was 0.59%, and the niobium-iron separation coefficient reached 5.61.

[0054] Example 6

[0055] This embodiment proposes an additive composition for separating niobium iron from niobium iron ore, comprising, by weight, 70 parts calcium oxide, 20 parts silicon oxide, and 8 parts fluoride; wherein the fluoride is a mixture of magnesium fluoride and calcium fluoride, with a mass ratio of magnesium fluoride to calcium fluoride of 1:1.5.

[0056] This embodiment also proposes the application of the above-mentioned additive composition for separating niobium from niobium ore in the treatment of niobium concentrate, including: taking 5 kg of niobium concentrate, adding 1 kg of activated carbon as a reducing agent and 2.25 kg of additive composition to adjust the alkalinity to 3.5, mixing thoroughly in a ball mill, adding 0.5 L of 5% PVA solution, and molding the mixture into cylinders with a diameter of Φ0.5 m using a press and mold, drying for 12 h, and then placing them in a 10 L iron container, smelting at 1200 °C for 120 min under the condition of passing inert protective gas argon, cooling with the furnace, dissolving the slag phase with hydrochloric acid and HF acid, and ICP analysis results showing that the iron content in the slag phase decreased to 6.69%, the niobium content in the slag phase was 0.57%, and the niobium-iron separation coefficient reached 5.67.

[0057] We found that using a mixture of MgF2, CaF2, and BaF2 in a certain mass ratio of fluorides can increase the stability of niobium oxide, hinder its participation in the reduction reaction, and reduce the proportion of niobium flowing into the metal phase, thereby significantly improving the niobium-iron separation effect. Examples are as follows:

[0058] Example 7

[0059] This embodiment proposes an additive composition for separating niobium iron from niobium iron ore, comprising 70 parts calcium oxide, 20 parts silicon oxide, and 8 parts fluoride by weight; wherein the fluoride is a mixture of magnesium fluoride, calcium fluoride, and barium fluoride, with a mass ratio of magnesium fluoride, calcium fluoride, and barium fluoride of 1:1.2:3.

[0060] This embodiment also proposes the application of the above-mentioned additive composition for separating niobium from niobium ore in the treatment of niobium concentrate, including: taking 5 kg of niobium concentrate, adding 1.1 kg of activated carbon as a reducing agent and 1.75 kg of additive composition to adjust the alkalinity to 3.5, mixing thoroughly in a ball mill, adding 0.5 L of 5% PVA solution, and molding the mixture into cylinders with a diameter of Φ0.5 m using a press and mold, drying for 12 h, and then placing it in a 10 L iron container, melting it at 1300 °C for 100 min under the condition of passing inert protective gas argon, and cooling it with the furnace. After dissolving the slag phase with hydrochloric acid and HF acid, ICP analysis showed that the iron content in the slag phase decreased to 6.25%, the niobium content in the slag phase was 0.61%, and the niobium-iron separation coefficient reached 6.5.

[0061] Example 8

[0062] This embodiment proposes an additive composition for separating niobium iron from niobium iron ore, comprising, by weight, 70 parts calcium oxide, 20 parts silicon oxide, and 8 parts fluoride; wherein the fluoride is a mixture of magnesium fluoride, calcium fluoride, and barium fluoride, with a mass ratio of magnesium fluoride, calcium fluoride, and barium fluoride of 1:1:2.5.

[0063] This embodiment also proposes the application of the above-mentioned additive composition for separating niobium from niobium ore in the treatment of niobium concentrate, including: taking 5 kg of niobium concentrate, adding 1.1 kg of activated carbon as a reducing agent and 2 kg of additive composition to adjust the alkalinity to 3.5, mixing thoroughly in a ball mill, adding 0.5 L of 5% PVA solution, and using a press and mold to form the mixture into cylinders with a diameter of Φ0.5 m. After drying for 12 h, it is placed in a 10 L iron container and smelted at 1300 °C for 100 min under the condition of passing inert protective gas argon. After cooling with the furnace, the slag phase is dissolved with hydrochloric acid and HF acid. ICP analysis results show that the iron content in the slag phase is reduced to 6.18%, the niobium content in the slag phase is 0.58%, and the niobium-iron separation coefficient reaches 6.2.

[0064] Example 9

[0065] This embodiment proposes an additive composition for separating niobium iron from niobium iron ore, comprising 70 parts calcium oxide, 20 parts silicon oxide, and 8 parts fluoride by weight; wherein the fluoride is a mixture of magnesium fluoride, calcium fluoride, and barium fluoride, with a mass ratio of magnesium fluoride, calcium fluoride, and barium fluoride of 1:1.5:2.

[0066] This embodiment also proposes the application of the above-mentioned additive composition for separating niobium from niobium ore in the treatment of niobium concentrate, including: taking 5 kg of niobium concentrate, adding 1.1 kg of activated carbon as a reducing agent and 2 kg of additive composition to adjust the alkalinity to 3.5, mixing thoroughly in a ball mill, adding 0.5 L of 5% PVA solution, and using a press and mold to form the mixture into cylinders with a diameter of Φ0.5 m. After drying for 12 h, it is placed in a 10 L iron container and smelted at 1300 °C for 100 min under the condition of passing inert protective gas argon. After cooling with the furnace, the slag phase is dissolved with hydrochloric acid and HF acid. ICP analysis results show that the iron content in the slag phase is reduced to 6.15%, the niobium content in the slag phase is 0.55%, and the niobium-iron separation coefficient reaches 6.3.

[0067] Comparative Example 1

[0068] The difference between this comparative example and Example 1 is that no additive composition was added, as detailed below:

[0069] This comparative example demonstrates its application in treating niobium-iron concentrate, including: taking 5 kg of niobium-iron concentrate, adding 0.9 kg of activated carbon as a reducing agent, mixing thoroughly in a ball mill, adding 0.5 L of 5% PVA solution, and using a press and mold to form the mixture into cylinders with a diameter of Φ0.5 m. After drying for 12 h, it is placed in a 10 L iron container and smelted at 1300 °C for 100 min under the condition of passing inert protective gas argon. After cooling with the furnace, the slag phase is dissolved with hydrochloric acid and HF acid. ICP analysis results show that the iron content in the slag phase is reduced to 12.07%, the niobium content in the slag phase is 0.34%, and the niobium-iron separation coefficient is 1.87.

[0070] Comparative Example 2

[0071] The difference between this comparative example and Example 1 is that the melting temperature is higher, at 1400°C. Other reaction conditions and additive compositions are the same as in Example 1. ICP analysis results show that the iron content in the slag phase is reduced to 1.79%, the niobium content in the slag phase is 0.08%, and the niobium-iron separation coefficient is 2.97.

[0072] Table 2. Elemental analysis results of iron- and niobium-removed crude concentrate slag from Examples 1-9

[0073]

[0074] Table 3. Elemental analysis results of iron- and niobium-removed crude concentrate slag from Comparative Examples 1-2

[0075]

[0076] Tables 2 and 3 further list the elements of the niobium-removed rough concentrate slag phase after treatment. It can be seen that Examples 1-9 all have good separation effects on niobium and iron, among which Examples 6-9 using three fluorides have more obvious separation effects on niobium and iron.

[0077] This invention's method is highly adaptable to high-iron niobium concentrates and is equally applicable to alkaline or acidic niobium concentrates. By controlling alkalinity, smelting atmosphere, and smelting temperature, it selectively and centrally reduces iron oxides in niobium crude concentrate to metallic iron, providing favorable conditions for subsequent separation to obtain high-quality niobium concentrate with iron removed and containing niobium. This invention eliminates the need for multiple processes, is simple to operate, and uses inexpensive additives, making it beneficial for industrial applications. Furthermore, the relatively low temperature aligns with energy conservation and emission reduction policies, reducing energy consumption costs.

[0078] The specific embodiments of the present invention described above do not constitute a limitation on the scope of protection of the present invention. Any other corresponding changes and modifications made in accordance with the technical concept of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. The application of an additive composition for separating niobium iron from niobium iron ore in the processing of niobium iron ore, comprising: A mixture of niobium iron ore, a reducing agent, and an additive composition is mixed, followed by the addition of a binder. The mixture is then pressed into a block, dried, and placed in a container. The block is then smelted at 1150-1300°C under an inert gas atmosphere. The additive composition, by weight, comprises 45-70 parts calcium oxide, 15-40 parts silicon oxide, and 5-10 parts fluoride. The fluoride is a mixture of magnesium fluoride, calcium fluoride, and barium fluoride. The mass ratio of magnesium fluoride, calcium fluoride, and barium fluoride is 1:(1-1.5):(2-3).

2. The application according to claim 1, characterized in that, The mass ratio of the columbite ore to the reducing agent is 100:(18-22); and / or, the mass ratio of the columbite ore to the additive is 100:(35-45).

3. The application according to claim 1, characterized in that, The melting time at 1150-1300℃ is more than 100 minutes.

4. The application according to claim 1, characterized in that, The reducing agent is one or more of activated carbon, oil coke, pulverized coal, coke and heavy oil.

5. The application according to claim 1, characterized in that, The adhesive is a solution of one or more of PVA, water glass, and clay.

6. The application according to claim 1, characterized in that, The binder is a PVA solution with a mass concentration of 5%-8%, and the material ratio of the niobium iron ore to the PVA solution is 5 kg:(0.5-0.8) L.

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