Efficient beneficiation method for niobium ore

Abstract

The invention discloses an efficient beneficiation method for niobium ore, and belongs to the technical field of beneficiation. The method comprises the steps that raw niobium ore is crushed and then subjected to weak magnetic treatment to remove strong magnetic iron ore, weak magnetic tailings are subjected to desliming treatment and then subjected to strong magnetic treatment, and strong magnetic concentrate and strong magnetic tailings are obtained; the strong magnetic concentrate is subjected to desilicication reverse flotation, and desilicication tailings are obtained; the desilicication tailings are subjected to dehydration, reagent removal and desliming and then subjected to niobium flotation I, and niobium concentrate I is obtained; the strong magnetic tailings are subjected to niobium flotation II, and niobium concentrate II is obtained; and after the niobium concentrate II is subjected to dehydration and reagent removal treatment, upgrading flotation III is carried out, and niobium concentrate III is obtained. According to the method, according to the mineral composition characteristics of the niobium ore, magnetic separation is firstly carried out, and different flotation methods are respectively adopted for magnetic niobium-containing minerals and non-magnetic niobium-containing minerals for enrichment of the niobium ore, so that not only is the total recovery efficiency of the niobium ore improved, but also the niobium concentrate grade is improved, and the reagent consumption is reduced.

Description

Technical Field

[0001] The invention relates to a niobium ore dressing method, in particular to a niobium ore efficient flotation development and utilization method, belonging to the technical field of ore dressing. Background Art

[0002] Niobium is a lustrous gray-white transition metal with characteristics such as corrosion resistance and high ductility. It has superconductivity at low temperatures. Among metal materials, niobium is the most effective microalloying element and is a key element in aerospace, superconducting materials, medical materials, metallurgical industry and other fields.

[0003] The primary deposits of niobium are relatively rare in nature. Currently, there are two types of niobium deposits, namely granite-related deposits (including rare metal granite type and pegmatite type, the main niobium-containing minerals are niobium iron ore, niobium iron rutile, brown yttrium niobium ore, black rare gold ore, etc.) and deposits related to alkaline and basic-ultramafic complexes (the main niobium-containing minerals are pyrochlore, cerium niobium perovskite, calcite, etc.). The world's niobium ore resources are mainly concentrated in Brazil and Canada. The domestic niobium ore resources are relatively abundant, but most of them are low-grade ores with many associated minerals, which are difficult to meet domestic demand. Therefore, it is urgent to develop technologies for efficiently enriching niobium resources from low-grade ores.

[0004] Flotation is one of the most important methods for industrial recovery of various niobium minerals, in which collectors play a key role in collection and enrichment. Niobium mineral flotation collectors include fatty acids, arsenic acid, hydroxamic acid, phosphonic acid and amines. Although bisphosphonic acid and arsenic acid collectors have good selectivity for niobium-containing minerals such as niobium iron ore and pyrochlore, these collectors will cause serious pollution to the environment during preparation and use. Although fatty acids have a strong collection ability for niobium minerals, they usually collect gangue minerals such as carbonates and silicates at the same time, and their selectivity is poor. Hydroxamic acid has a high selective chelating ability for metal ions, such as iron ions, which inevitably causes the selective enrichment of iron-containing gangue minerals during the niobium flotation process, which has a huge impact on the flotation collection efficiency and product quality of niobium. Amine collectors can effectively capture niobium minerals, but their disadvantage is that they also have strong capture properties for ore mud and siliceous minerals, and the foam has high viscosity, resulting in a high amount of niobium in the tailings, which greatly reduces the recovery rate and grade of niobium ore. Summary of the invention

[0005] In view of the technical problems in the prior art of niobium ore dressing process such as poor selectivity, large reagent consumption, high doping of ore mud and siliceous minerals, low niobium ore recovery rate and low recovery grade, the purpose of the present invention is to provide a high-efficiency niobium ore dressing method. According to the mineral composition characteristics of niobium ore, the method firstly performs magnetic separation and enriches niobium minerals by adopting different flotation methods for magnetic niobium-containing minerals and non-magnetic niobium-containing minerals, which not only improves the total recovery efficiency of niobium ore, but also improves the grade of niobium concentrate and reduces reagent consumption.

[0006] In order to achieve the above technical objectives, the present invention provides an efficient beneficiation method for niobium ore, which comprises the following steps:

[0007] 1) After the niobium ore is crushed, it is subjected to weak magnetic treatment to remove the strongly magnetic iron ore. After the weak magnetic tailings are desludged, they are subjected to strong magnetic treatment to obtain strong magnetic concentrate and strong magnetic tailings;

[0008] 2) After the pH of the strong magnetic concentrate is adjusted, flotation reagents including starch inhibitors and etheramine collectors are added to perform desiliconization reverse flotation to obtain desiliconized tailings;

[0009] 3) After dehydrating, removing drugs and desludging the desiliconized tailings, flotation reagents including fluorosilicic acid inhibitors and amine collectors are added to carry out niobium flotation I to obtain niobium concentrate I;

[0010] 4) The strong magnetic tailings are added with flotation reagents including silicon mineral inhibitors and hydroxamic acid metal complex collectors to carry out niobium flotation II to obtain niobium concentrate II.

[0011] 5) After dehydration and de-doping treatment of the niobium concentrate II, flotation reagents including a fluorosilicic acid inhibitor-activator and an amine collector are added to carry out quality-enhancing flotation III to obtain niobium concentrate III.

[0012] The niobium ore of the present invention contains the main minerals of calcite [CaCO3], dolomite [CaMg(CO3)2], ankerite [Ca(Mg,Fe)(CO3)2], potassium feldspar [K2O·Al2O3·6SiO2], phlogopite [KMg3(Si3AlO 10 )(OH)2], biotite [K(Mg,Fe)3(Al,Fe)Si3O 10 )(OH,F)2], magnetite [Fe3O4], apatite [Ca5(PO4)3(F,OH)] and pyrochlore [(Ca,Na)2(Nb,Ti)2O6F], etc.

[0013] The present invention is based on the phase composition and distribution characteristics of niobium ore, based on the fact that niobium ore mainly contains gangue minerals such as iron minerals, siliceous minerals and niobium minerals, and conventional amine collectors are more sensitive to siliceous minerals, and hydroxamic acid collectors are difficult to separate iron and niobium. The key to the present invention is to first perform pre-separation by magnetic separation, use weak magnetic separation to remove strongly magnetic iron ores such as magnetite, and then use strong magnetism to separate niobium minerals into two parts: magnetic niobium-containing minerals and non-magnetic niobium-containing minerals. The main gangue minerals in the magnetic niobium-containing minerals are iron minerals. The main gangue minerals of non-magnetic niobium-containing minerals are siliceous minerals. According to the mineral composition characteristics of magnetic niobium-containing minerals and non-magnetic niobium minerals, reasonable flotation reagent systems are designed respectively. After further desiliconization of magnetic niobium-containing minerals, amine collectors are used to achieve efficient flotation separation of niobium-containing minerals and iron gangue minerals. Hydroxamic acid metal complex collectors are used for non-magnetic niobium-containing minerals to achieve efficient separation of niobium-containing minerals and siliceous gangue minerals, and then amine collectors are further used for flotation and quality improvement to improve the grade of niobium ore. In summary, the present invention designs a reasonable mineral processing process, which can greatly improve the recovery rate of niobium ore and simplify the process flow.

[0014] As a preferred solution, the weak magnetic treatment adopts a magnetic field strength of 0.15-0.3 T. After the weak magnetic treatment, magnetite, ilmenite, hematite and the like with strong magnetism can be preferably removed, reducing the difficulty of subsequent iron-niobium flotation separation.

[0015] As a preferred solution, the strong magnetic treatment uses a magnetic field strength of 1.2 to 1.5 T. After the strong magnetic treatment, weakly magnetic iron minerals and associated niobium minerals can be separated from siliceous minerals. The main purpose is to achieve desiliconization and avoid the influence of siliceous minerals on the recovery of niobium ore by amine collectors.

[0016] As a preferred solution, in 2), the pH is adjusted to 10-11. Under the preferred pH conditions, favorable pH conditions are provided for the flotation of siliceous minerals by etheramine collectors.

[0017] As a preferred solution, the desiliconization reverse flotation includes a roughing flotation process. As a more preferred solution, the roughing reagent system is: starch inhibitor 300~800g / t; ether amine collector 100~300g / t. Starch inhibitor is mainly used to inhibit iron minerals. Ether amine collectors are specifically C 10 ~C 13 Etheramine acetate.

[0018] As a preferred solution, the niobium flotation I adopts a one-rough and three-fine flotation process; wherein, the reagent system for the rough selection is: 1500-2500g / t of fluorosilicic acid inhibitor, 100-300g / t of amine collector, and 30-80g / t of defoamer; the reagent system for the first fine selection is: 1500-2500g / t of fluorosilicic acid inhibitor, and 30-80g / t of amine collector; the reagent system for the second fine selection is: 1500-2500g / t of fluorosilicic acid inhibitor; the reagent system for the third fine selection is: 1300-1800g / t of fluorosilicic acid inhibitor. The fluorosilicic acid inhibitor is used as a pH adjuster on the one hand to adjust the pH range suitable for flotation, and on the other hand as an inhibitor, mainly used to inhibit iron minerals. After the siliceous minerals are separated by strong magnetic separation, the influence of the siliceous minerals on the separation of niobium minerals by amine collectors is greatly reduced. Defoamers such as P86.

[0019] As a more preferred solution, the amine collector includes a fatty diamine having 10 to 20 carbon atoms.

[0020] As a preferred solution, the niobium flotation II adopts a one-rough and three-fine flotation process; wherein the reagent system for the rough selection is: 50-150 g / t of silicon mineral inhibitor, 300-800 g / t of hydroxamic acid metal complex collector, and 30-80 g / t of frother; the reagent system for the first fine selection is: 30-80 g / t of silicon mineral inhibitor; the reagent system for the second fine selection is: 15-35 g / t of silicon mineral inhibitor; the reagent system for the third fine selection is: 5-15 g / t of silicon mineral inhibitor; the frother is further preferably BK205. Since the strong magnetic tailings also contain non-magnetic iron ore, etc., the use of hydroxamic acid metal complex collector and silicon mineral inhibitor can strengthen the flotation separation of silicon minerals and niobium minerals, and a small amount of non-magnetic iron minerals and the like enter the concentrate together with the niobium minerals, and the subsequent use of amine collectors is easy to further improve the quality of niobium minerals.

[0021] As a more preferred solution, the silicon mineral inhibitor includes at least one of sodium hexametaphosphate, carboxymethyl cellulose, tannin, water glass, salinized water glass, sodium fluorosilicate, fluorosilicic acid, and starch.

[0022] As a more preferred solution, the hydroxamic acid metal organic complex collector is composed of at least one of benzohydroxamic acid, salicylic hydroxamic acid, an alkyl hydroxamic acid having 5 to 9 carbon atoms, and Pb 2+ 、Zn 2+ 、Al 3+ , Cu 2+ , Fe 2+ , Fe 3+At least one of them is assembled in a mass ratio of 8:1 to 12:1. As a preferred solution, the quality-enhancing flotation III adopts a one-rough and two-fine flotation process; wherein the reagent system for the rough selection is: 1500 to 2000 g / t of fluorosilicic acid inhibitor-activator, 50 to 150 g / t of amine collector; the reagent system for the first fine selection is: 1500 to 2000 g / t of fluorosilicic acid inhibitor-activator, 10 to 30 g / t of amine collector; the reagent system for the second fine selection is: 1500 to 2000 g / t of fluorosilicic acid inhibitor-activator. In addition to its inhibitory effect on silicon minerals, fluorosilicic acid also has a strong activating effect on pyrochlore.

[0023] Compared with the prior art, the beneficial technical effects brought by the solution of the present invention are:

[0024] According to the phase composition and distribution characteristics of niobium ore, the present invention divides niobium ore into magnetic niobium-containing minerals and non-magnetic niobium-containing minerals through magnetic separation, and combines the mineral characteristics of magnetic niobium-containing minerals and non-magnetic niobium-containing minerals, fully considers the flotation separation behavior of impurities such as silicon and iron and niobium, and designs a reasonable flotation process to achieve efficient separation of niobium-containing components in magnetic minerals and non-magnetic minerals, which is beneficial to ensuring the overall niobium recovery rate, while improving the grade of niobium concentrate and reducing reagent consumption. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 The figure is a process flow chart of the efficient beneficiation of niobium ore according to the present invention. DETAILED DESCRIPTION

[0026] The following specific examples are intended to further illustrate the present invention, rather than to limit the scope of protection of the claims of the present invention.

[0027] Example 1

[0028] In this experiment, a pyrochlore-type niobium-containing ore was selected as the experimental research object. The following Table 1 shows the main chemical composition of the niobium-containing ore. Its composition is complex, and the content of valuable elements in the ore is low. The contents of Nb2O5 and TiO2 are 1.05% and 2.12% respectively, and the total iron content is 11.52%.

[0029]

[0030] The specific test process is as follows Figure 1 As shown by Figure 1It can be seen that after the original ore is crushed, it is screened and the coarse particles are returned to the crusher for further crushing. After the crushing, the ore is weakly magnetically treated, and a portion of the strong magnetic concentrate is removed at a magnetic field strength of 0.2T. Since fine-grained minerals are difficult to separate, the magnetic tailing needs to be desludged. The desludged mineral samples are subjected to strong magnetic separation under a magnetic field strength of 1.5T. The strong magnetic concentrate and strong magnetic tailings are flotated and separated according to their corresponding mineralogical characteristics. During the flotation of the strong magnetic concentrate, the influence of magnetic iron minerals on the flotation behavior of niobium needs to be avoided. Therefore, the main method adopts reverse flotation desiliconization pretreatment and the method of selecting niobium-containing minerals under acidic conditions of the amine method. The main reagent system used for reverse flotation desiliconization is: NaOH pH=10, corn starch 500g / t, C 10 Etheramine acetate (commercial product) 200g / t. Reverse flotation desiliconization adopts a roughing process, and the desiliconized tailings are dehydrated and de-doped, and after further removing fine mud particles, niobium mineral flotation tests are carried out.

[0031] In the flotation process of niobium-containing minerals, the reagent system adopted is mainly: 2000g / t of fluorosilicic acid, 50g / t of defoamer P86, and 200g / t of C16 saturated fatty diamine (commercial product). The main gangue minerals of pyrochlore minerals are mainly: SiO2 and iron-containing minerals. Therefore, in the flotation process of niobium-containing minerals, the flotation separation of pyrochlore and silicon dioxide and iron-containing minerals can be achieved according to the electrical properties of the mineral surface.

[0032] The main part of the niobium flotation process adopts a one-rough and three-fine flotation process. The main part of the concentration uses fluorosilicic acid as a depressant. The reagent system for the first concentration is: 2000g / t of fluorosilicic acid depressant, 50g / t of C16 saturated fatty diamine; the reagent system for the second concentration is: 2000g / t of fluorosilicic acid depressant; the reagent system for the third concentration is: 1500g / t of fluorosilicic acid depressant.

[0033] In the flotation process of strong magnetic tailings, the main body adopts hydroxamic acid-lead metal-based collector to strengthen the collection of niobium-containing minerals. The roughing reagent system is: tannic acid 100g / t as inhibitor, hydroxamic acid-lead metal-based collector, lead nitrate 50g / t, hydroxamic acid 500g / t, and BK205 50g / t as frother. Tannic acid is used as an inhibitor in the concentration section to gradually inhibit silicate minerals, and the medium ore is returned to the previous flotation section in turn. The reagent system for the first concentration is: tannic acid inhibitor 50g / t; the reagent system for the second concentration is: tannic acid inhibitor 25g / t; the reagent system for the third concentration is: tannic acid inhibitor 10g / t. After the first rough and three fine flotation process, dehydration and demedication are carried out. Niobium collectors are further used to improve the quality and sort niobium minerals. The reagent system used is 2000g / t of fluorosilicic acid and 100g / t of C16 saturated fatty diamine. The flotation process is mainly one coarse and two fine. The reagent system for the first fine is: 2000g / t of fluorosilicic acid and 20g / t of C16 saturated fatty diamine; the reagent system for the second fine is: 2000g / t of fluorosilicic acid.

[0034] The test results are shown in Table 2 below. The overall niobium flotation recovery rate is calculated based on the ore before magnetic separation. It can be seen from the experimental results that the grade of niobium concentrate has been significantly improved. The Nb2O5 grade in niobium concentrate 1 reached 38.27%, and the Nb2O5 grade in niobium concentrate 2 was 37.42%, which was significantly improved compared to the Nb2O5 content of 1.05% in the original ore. At the same time, the overall niobium flotation recovery rate is also quite impressive. The recovery rate of niobium concentrate 1 is 31.74%, and the recovery rate of niobium concentrate 2 is 36.35%, and the sum of the two is close to 70%, which shows that the beneficiation method of the present invention can effectively enrich niobium minerals from low-grade pyrochlore-type niobium-containing original ore, realize the efficient separation of niobium-containing components in magnetic minerals and non-magnetic minerals, and ensure the recovery rate of niobium while improving the grade of niobium concentrate. The feasibility and effectiveness of the method in practical applications are verified, and strong technical support is provided for the development and utilization of low-grade niobium ore resources.

[0035]

[0036] Example 2

[0037] In this experiment, a pyrochlore-type niobium-containing ore similar to that in Example 1 was selected as the experimental research object. The composition of the ore is complex, and the content of valuable elements in the ore is low. The contents of Nb2O5 and TiO2 are 1.05% and 2.12% respectively, and the total iron content is 11.52%.

[0038] The specific test process is as follows Figure 1The same, but the reagent system is different. After the raw ore is crushed, it is screened and the coarse particles are returned to the crusher for further crushing. After crushing, the ore is weakly magnetically treated, and a portion of the strong magnetic concentrate is removed at a magnetic field strength of 0.2T. Since fine-grained minerals are difficult to separate, the magnetic tailing needs to be desludged. The desludged mineral samples are subjected to strong magnetic separation under a magnetic field strength of 1.5T. The strong magnetic concentrate and the strong magnetic tailings are flotated and separated according to their corresponding mineralogical characteristics. During the flotation of the strong magnetic concentrate, the influence of magnetic iron minerals on the flotation behavior of niobium needs to be avoided. Therefore, the main method adopts reverse flotation desiliconization pretreatment and the method of selecting niobium-containing minerals under acidic conditions of the amine method. The main reagent system used for reverse flotation desiliconization is: NaOH pH=10.5, corn starch 500g / t, C 10 Etheramine acetate (commercial product) 200g / t. Reverse flotation desiliconization adopts a roughing process, and the desiliconized tailings are dehydrated and de-doped, and after further removing fine mud particles, niobium mineral flotation tests are carried out.

[0039] In the flotation process of niobium-containing minerals, the reagent system adopted is mainly: 2000g / t of fluorosilicic acid, 50g / t of defoamer P86, and 200g / t of C18 saturated fatty diamine (commercial product). The main gangue minerals of pyrochlore minerals are mainly: SiO2 and iron-containing minerals. Therefore, in the flotation process of niobium-containing minerals, the flotation separation of pyrochlore and silicon dioxide and iron-containing minerals can be achieved according to the electrical properties of the mineral surface.

[0040] The main part of the niobium flotation process adopts a one-rough and three-fine flotation process. The main part of the concentration uses fluorosilicic acid as a depressant. The reagent system for the first concentration is: 2000g / t of fluorosilicic acid depressant, 50g / t of C18 saturated fatty diamine; the reagent system for the second concentration is: 2000g / t of fluorosilicic acid depressant; the reagent system for the third concentration is: 1500g / t of fluorosilicic acid depressant.

[0041] In the flotation process of strong magnetic tailings, hydroxamic acid-lead metal-based collectors are mainly used to enhance the capture of niobium-containing minerals. Tannin inhibitors 80g / t and hydroxamic acid-lead complex collectors (benzohydroxamic acid and Pb 2+ The niobium ore is separated by a 10:1 mass ratio) of 440g / t and a frother BK205 of 50g / t. Tannin inhibitors of 40g / t, 20g / t and 8g / t are used in the three concentrators respectively, and the middlings are returned in sequence. After the first roughing and three fine flotation processes, dehydration and demedication are carried out. Niobium collectors are further used to improve the quality of niobium ore. A one roughing and two fines process is adopted. Fluorosilicic acid inhibitor-activator 1800g / t and C18 saturated fatty diamine 80g / t are added in the roughing; 1800g / t of fluorosilicic acid and 15g / t of C18 saturated fatty diamine are used in the first concentrator; only 1800g / t of fluorosilicic acid is retained in the second concentrator.

[0042] The test results are shown in Table 3 below. The Nb2O5 grade of niobium concentrate 1 is 37.89%, and the recovery rate is 29.85%; the Nb2O5 grade of niobium concentrate 2 is 36.54%, and the recovery rate is 34.72%, and the total recovery rate is 64.57%. Compared with Example 1, after adjusting the dosage of reagents, the grade of niobium concentrate is slightly reduced, but the reagent consumption is reduced, and the process stability is improved, which verifies the flexibility of the present invention in parameter optimization.

[0043]

Claims

1. An efficient beneficiation method for niobium ore, characterized in that: The following steps are involved: 1) After the niobium ore is crushed, it is subjected to weak magnetic treatment to remove the strongly magnetic iron ore. After the weak magnetic tailings are desludged, they are subjected to strong magnetic treatment to obtain strong magnetic concentrate and strong magnetic tailings; 2) After the pH of the strong magnetic concentrate is adjusted, flotation reagents including starch inhibitors and etheramine collectors are added to perform desiliconization reverse flotation to obtain desiliconized tailings; 3) After dehydrating, removing drugs and desludging the desiliconized tailings, flotation reagents including fluorosilicic acid inhibitors and amine collectors are added to carry out niobium flotation I to obtain niobium concentrate I; 4) adding the strong magnetic tailings to a flotation agent including a silicon mineral inhibitor and a hydroxamic acid metal complex collector to carry out niobium flotation II to obtain niobium concentrate II; 5) After dehydration and de-doping treatment, flotation reagents including fluorosilicic acid inhibitor-activator and amine collector are added to the niobium concentrate II to carry out quality-enhancing flotation III to obtain niobium concentrate III.

2. The efficient beneficiation method of niobium ore according to claim 1, characterized in that: The weak magnetic treatment adopts a magnetic field strength of 0.15~0.3T; The strong magnetic treatment adopts a magnetic field strength of 1.2~1.5T.

3. The efficient beneficiation method of niobium ore according to claim 1, characterized in that: 2) Adjust pH to 10-11.

4. The efficient beneficiation method of niobium ore according to claim 1, characterized in that: The desiliconization reverse flotation comprises a primary roughing flotation process; The reagent system for rough selection is: 300-800 g / t of starch inhibitor and 100-300 g / t of etheramine collector.

5. The efficient beneficiation method of niobium ore according to claim 1, characterized in that: The niobium flotation I adopts a one-rough three-fine flotation process; in, The reagent system for rough selection is: 1500~2500g / t of fluorosilicic acid inhibitor, 100~300g / t of amine collector, and 30~80g / t of defoamer; The reagent system for primary selection is: 1500~2500g / t of fluorosilicic acid inhibitor and 30~80g / t of amine collector; The reagent system for secondary concentration is: Fluorosilicic acid inhibitor 1500~2500g / t; The reagent system for the third concentration is: 1300~1800g / t of fluosilicic acid inhibitor.

6. The efficient beneficiation method of niobium ore according to claim 5, characterized in that: The amine collector includes aliphatic diamines having 10 to 20 carbon atoms.

7. The efficient beneficiation method of niobium ore according to claim 1, characterized in that: The niobium flotation II adopts a one-rough and three-fine flotation process; in, The reagent system for roughing is: 50~150g / t of silicon mineral inhibitor, 300~800g / t of hydroxamic acid metal complex collector, 30~80g / t of foaming agent; The reagent system for primary concentration is: 30~80g / t of silicon mineral inhibitor; The reagent system for secondary concentration is: silicon mineral inhibitor 15~35g / t; The reagent system for the third concentration is: 5~15g / t of silicon mineral inhibitor.

8. The efficient beneficiation method of niobium ore according to claim 7, characterized in that: The silicon mineral inhibitor includes at least one of sodium hexametaphosphate, carboxymethyl cellulose, tannin, water glass, salinized water glass, sodium fluorosilicate, fluorosilicic acid, and starch; The hydroxamic acid metal organic complex collector is composed of at least one of benzohydroxamic acid, salicylic hydroxamic acid, an alkyl hydroxamic acid having 5 to 9 carbon atoms, and Pb 2+ 、Zn 2+ 、Al 3+ , Cu 2+ , Fe 2+ , Fe 3+ At least one of them is assembled in a coordination ratio of 8:1 to 12:

1.

9. The efficient beneficiation method of niobium ore according to claim 1, characterized in that: The upgrading flotation III adopts a one coarse and two fine flotation process; in, The reagent system for roughing is: 1500~2000g / t of fluosilicic acid inhibitor-activator, 50~150g / t of amine collector; the reagent system for primary cleaning is: 1500~2000g / t of fluosilicic acid inhibitor-activator, 10~30g / t of amine collector; The reagent system for secondary concentration is: 1500~2000g / t of fluosilicic acid inhibitor-activator.

10. The efficient beneficiation method of niobium ore according to claim 9, characterized in that: The amine collector includes aliphatic diamines having 10 to 20 carbon atoms.

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