Mineral processing equipment and methods for enriching fine-grained, low-grade ilmenite from titanium tailings.

Abstract

The application provides a beneficiation device for enriching fine-grained low-grade ilmenite from titanium selection tailings, which comprises a first-stage gravity separation device, a second-stage gravity separation device, a third-stage gravity separation device and a magnetic separation device, the overflow port of the first-stage gravity separation device is connected with the feeding port of the second-stage gravity separation device, the overflow port of the second-stage gravity separation device is connected with the feeding port of the third-stage gravity separation device, and the overflow port of the third-stage gravity separation device is connected with the feeding port of the magnetic separation device; and a beneficiation method for enriching fine-grained low-grade ilmenite from titanium selection tailings, which comprises four steps of coarse-grained enrichment and discarding, medium-grained enrichment and discarding, fine-grained enrichment and discarding and slime recovery. The method combines classification operation, magnetic separation process, gravity separation process and regrinding process organically, and fully utilizes the physical property difference between ilmenite and gangue minerals to efficiently separate, and has the characteristics of low energy consumption, small land occupation and environmental friendliness, and the water generated in the operation process can be recycled.

Description

Technical Field

[0001] This invention belongs to the field of mineral processing engineering technology, specifically relating to a beneficiation method and apparatus for enriching fine-grained, low-grade ilmenite from titanium tailings. Background Technology

[0002] The Panxi region boasts leading vanadium-titanium-iron resources in China and even the world, with titanium reserves accounting for 93% of the national total and ranking first in the world. However, in the comprehensive utilization of vanadium-titanium magnetite in the Panxi region, especially the valuable titanium resources, the utilization rate relative to the original ore is relatively low, resulting in a significant waste of resources. This is the most prominent problem in the comprehensive utilization of vanadium-titanium magnetite in the Panxi region.

[0003] In iron ore beneficiation tailings and early titanium beneficiation tailings, -38μm fine-grained ilmenite accounts for about 50% of the total. Recovering this portion of ilmenite is crucial for improving the overall titanium beneficiation recovery rate. Furthermore, even after enriching metallic titanium in the tailings product at the Jiangnan Titanium Beneficiation Plant, the titanium grade still remains around 5%, indicating significant resource waste. As for the usable titanium resources entering the iron ore beneficiation tailings, there are problems such as the similar properties of the valuable mineral ilmenite and the gangue mineral phosphogypsum, severe mudification of the titanium ore during the iron ore beneficiation process, and a high content of -38μm fine particles, all of which present considerable challenges for both magnetic separation and flotation. Therefore, achieving efficient tailings removal of gangue minerals, improving the grade of ilmenite feed, and avoiding interference from gangue minerals during flotation are effective ways to improve the recovery rate of fine-grained ilmenite. However, in high-gradient magnetic separation, as the background field strength increases, the gangue mineral inclusion rate increases, and the pre-selection efficiency decreases. In particular, a large amount of fine-grained pyroxene enters the flotation process along with the magnetic separation concentrate, exacerbating the problem of fine-grained ilmenite recovery. Traditional gravity separation devices, such as shaking tables and suspension tables, cannot achieve high-throughput gravity separation of ultrafine particles. Therefore, developing a separation process for efficient recovery of fine-grained ilmenite is an important research topic. Summary of the Invention

[0004] The purpose of this invention is to provide a simple and environmentally friendly beneficiation method and apparatus for enriching fine-grained low-grade ilmenite from titanium tailings in order to solve the problems in the prior art.

[0005] To achieve the above objectives, the present invention provides the following mineral processing apparatus:

[0006] A mineral processing device for enriching fine-grained, low-grade ilmenite from titanium tailings includes a first-stage gravity separator, a second-stage gravity separator, a third-stage gravity separator, and a magnetic separator. The overflow port of the first-stage gravity separator is connected to the inlet of the second-stage gravity separator, the overflow port of the second-stage gravity separator is connected to the inlet of the third-stage gravity separator, and the overflow port of the third-stage gravity separator is connected to the inlet of the magnetic separator. The first-stage gravity separator includes a hydrocyclone, a gravity column, and a grinding mill. The second-stage gravity separator includes a hydrocyclone, a gravity column, and a gravity column. The third-stage gravity separator includes a gravity column and a grinding mill. The magnetic separation device includes a gravity separation column and a No. 6 gravity separation column; the magnetic separation device includes a high-intensity magnetic separator; in the first-stage gravity separation device, the underflow port of the No. 1 hydrocyclone is connected to the feed inlet of the No. 1 gravity separation column, the underflow port of the gravity separation column is connected to the feed inlet of the grinding mill, and the grinding mill and the reflux device are connected to the feed inlet of the No. 1 hydrocyclone; in the second-stage gravity separation device, the underflow port of the No. 2 hydrocyclone is connected to the feed inlet of the No. 2 gravity separation column, and the underflow port of the No. 2 gravity separation column is connected to the feed inlet of the No. 3 gravity separation column; in the third-stage gravity separation device, the underflow port of the No. 4 gravity separation column is connected to the feed inlet of the No. 5 gravity separation column, and the underflow port of the No. 5 gravity separation column is connected to the feed inlet of the No. 6 gravity separation column.

[0007] Preferably, a thickener is also provided between the first-stage gravity separation device, the second-stage gravity separation device, the third-stage gravity separation device and the magnetic separation device. A thickener #1 is provided between the first-stage gravity separation device and the second-stage gravity separation device, a thickener #2 is provided between the second-stage gravity separation device and the third-stage gravity separation device, and a thickener #3 is provided between the third-stage gravity separation device and the magnetic separation device.

[0008] Preferably, the concentrate outlets of the first-stage gravity separator, the second-stage gravity separator, the third-stage gravity separator, and the magnetic separator are all connected to the concentrate collection box, and a #4 thickener and a #1 filter press are sequentially installed in front of the feed inlet of the concentrate collection box.

[0009] Preferably, the tailings outlets of the first-stage gravity separator, the second-stage gravity separator, the third-stage gravity separator, and the magnetic separator are all connected to the tailings collection box, and a No. 5 thickener and a No. 2 filter press are installed sequentially in front of the inlet of the tailings collection box.

[0010] The functions of hydrocyclones #1, #2, and #4 are to classify and deslim the materials, enabling each unit to classify the feed material by particle size and providing the sorting equipment in each step with materials of suitable particle size.

[0011] The functions of gravity separation columns 1, 2, 3, 5, and 6, as well as the high-intensity magnetic separator, are to separate materials, that is, to separate useful minerals from useless gangue minerals.

[0012] Among them, the grinding mill is a crushing and grinding equipment used to grind coarse minerals and realize the individual liberation of useful metal minerals and useless gangue minerals.

[0013] Thickener #1, Thickener #2, Thickener #3, Thickener #4, Thickener #5, Filter Press #1, Filter Press #2. Thickeners are used to thicken slurries with lower concentrations, while filter presses are used to dewater slurries with higher concentrations.

[0014] Based on the overall inventive concept, the present invention also provides a mineral processing method for enriching fine-grained, low-grade ilmenite from titanium tailings, comprising the following steps:

[0015] S1. Coarse-grained enrichment and waste disposal: The fine-grained low-grade ilmenite raw material is subjected to the first classification treatment to obtain classification underflow 1 and classification overflow 1. The obtained classification underflow 1 is ground and then subjected to the first classification treatment again.

[0016] S2, medium-grain enrichment and waste disposal: the graded overflow 1 undergoes a second graded treatment to obtain graded underflow 2 and graded overflow 2. The graded underflow 2 is separated twice using gravity separation, namely roughing and cleaning. The concentrate product from the roughing is then cleaned again, and the final concentrate 2 is used as the final concentrate product.

[0017] S3, Fine-grained enrichment and waste disposal: The graded overflow 2 undergoes a third graded treatment to obtain graded underflow 3 and graded overflow 3. The graded underflow 3 is separated twice using gravity separation, namely roughing and cleaning. The concentrate product from the roughing is then cleaned again to finally obtain concentrate 3, which enters the final concentrate product.

[0018] S4, Sludge Recovery: The graded overflow 3 is subjected to magnetic separation, and finally the concentrate 4 is entered into the final concentrate product.

[0019] Preferably, in step S1, the underflow grinding process involves grinding 90% of the ilmenite sample to a particle size of -75μm and then mixing it into the raw material for classification.

[0020] Preferably, the grinding in step S1 is performed using a grinding equipment, and the feed concentration of the grinding equipment is 20%-40%.

[0021] Preferably, the magnetic separation in step S4 uses a high-intensity magnetic separator with a magnetic field strength of 10-24 kOe.

[0022] Preferably, the grading process in steps S1 and S2 is performed using a hydrocyclone; the feed concentration of the hydrocyclone is 5%-20%, and the feed pressure is 0.10-0.20 MPa. The first grading process refers to grading using a hydrocyclone, not sieving, and the proportion of particles with a diameter of +75 μm in the underflow of the hydrocyclone is above 85%.

[0023] Preferably, the graded underflow 1, graded underflow 2, and graded underflow 3 obtained in steps S1, S2, and S3 are processed by a reselection method, and the equipment for the reselection method is a reselection column.

[0024] Preferably, tailings are obtained after the processing in steps S1, S2, S3 and S4. The tailings are then collected, merged and dehydrated before entering the final tailings product.

[0025] Preferably, in steps S2, S3, and S4, concentrate 2, concentrate 3, and concentrate 4 are combined and dehydrated to form the final concentrate product.

[0026] Preferably, the clarified waste liquid generated from the dehydration treatment is used for gravity separation.

[0027] Preferably, the particle size of the first classification is +75μm, and the proportion of particles with a diameter of +75μm in the classification underflow 1 generated by the treatment is more than 85%.

[0028] The particle size of the feed for the second classification process is -75 to +38 μm, and the particle size of the resulting underflow 2 is more than 80% -75 to +38 μm.

[0029] The particle size of the feed in the third stage of classification is -38μm, and the particle size of the underflow 3 produced is more than 70% -38+10μm.

[0030] In S1, the underflow of the primary gravity separator (2) is mainly composed of +75μm particles, accounting for more than 85% of the total. The feed concentration of the primary gravity separator is 30%-40%, and the yield of concentrate 1 is 10%-30%.

[0031] In S2, the feed for gravity separation in the first rougher (6) stage (2) is mainly -75 +38 μm, accounting for more than 80%. The feed concentration of the #2 gravity separation column (6) is 30%-40%, and the yield of rough concentrate 1 is 50%-70%. The feed concentration of the tertiary gravity separation column is 30%-40%, and the yield of concentrate 2 is 20%-30%.

[0032] In the S3 fourth-stage gravity separation column, the feed is predominantly -38μm, accounting for over 90%, with a feed concentration of 10%-20%. The underflow yield (3) is 50%-60%, primarily composed of -38μm +10μm, accounting for over 70%. In the fifth-stage gravity separation column, the feed is underflow (3), with a feed concentration of 30%-40%, and the rougher-concentrate yield (2) is 40%-60%. In the sixth-stage gravity separation column, the feed concentration is 30%-40%, and the concentrate yield (3) is 10%-20%.

[0033] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0034] 1. The method of the present invention organically combines grading, magnetic separation, gravity separation and regrinding processes, making full use of the differences in physical properties between ilmenite and gangue minerals for efficient separation. This beneficiation method has the characteristics of low energy consumption, small footprint and environmental friendliness, and the water generated during the operation can be recycled.

[0035] 2. This invention classifies ore samples and selectively sorts different particle sizes, improving the overall ore sorting effect. This allows for a relatively simple process to process fine-grained ilmenite. Furthermore, the overflow of the -0.038mm ilmenite classification contains extremely high levels of ultrafine particles, which have extremely high viscosity at high concentrations and very low free settling velocity, making gravity separation ineffective. Therefore, magnetic separation is used to recover the titanium-containing minerals. The combination of gravity and magnetic separation maximizes resource utilization. Attached image description:

[0036] To more clearly illustrate the technical solutions of the embodiments of this disclosure, the accompanying drawings of the embodiments will be briefly described below. Obviously, the drawings described below only relate to some embodiments of this disclosure and are not intended to limit this disclosure.

[0037] Figure 1 This is a schematic diagram of an apparatus for a mineral processing method that enriches fine-grained, low-grade ilmenite from titanium tailings.

[0038] In the diagram, 1. Hydrocyclone #1; 2. Gravity separation column #1; 3. Grinding mill; 4. Thickener #1; 5. Hydrocyclone #2; 6. Gravity separation column #2; 7. Gravity separation column #3; 8. Thickener #2; 9. Gravity separation column #4; 10. Gravity separation column #5; 11. Gravity separation column #6; 12. Thickener #3; 13. High-intensity magnetic separator; 14. Filter press #1; 15. Thickener #4; 16. Filter press #2; 17. Thickener #5. Detailed Implementation

[0039] Example 1:

[0040] A mineral processing device for enriching fine-grained, low-grade ilmenite from titanium tailings, such as... Figure 1 As shown, the system includes a first-stage gravity separator, a second-stage gravity separator, a third-stage gravity separator, and a magnetic separator. The overflow port of the first-stage gravity separator is connected to the inlet of the second-stage gravity separator, the overflow port of the second-stage gravity separator is connected to the inlet of the third-stage gravity separator, and the overflow port of the third-stage gravity separator is connected to the inlet of the magnetic separator. The first-stage gravity separator includes a hydrocyclone 1, a gravity separation column 2, and a grinding mill 3. The second-stage gravity separator includes a hydrocyclone 5, a gravity separation column 6, and a gravity separation column 7. The third-stage gravity separator includes a gravity separation column 9, a gravity separation column 10, and a gravity separation column 11. The magnetic separator includes a high-intensity magnetic separator 13.

[0041] Preferably, in the first-stage gravity separation device, the underflow port of the #1 hydrocyclone 1 is connected to the feed inlet of the #1 gravity separation column 2, the underflow port of the gravity separation column 2 is connected to the feed inlet of the grinding mill 3, and the grinding mill 3 and the reflux device are connected to the feed inlet of the #1 hydrocyclone 1.

[0042] Preferably, in the second-stage gravity separation device, the underflow port of the #2 hydrocyclone 5 is connected to the inlet of the #2 gravity separation column 6, and the underflow port of the #2 gravity separation column 6 is connected to the inlet of the #3 gravity separation column 7.

[0043] Preferably, in the third-stage gravity separation device, the underflow port of gravity separation column 9 is connected to the inlet of gravity separation column 10, and the underflow port of gravity separation column 10 is connected to the inlet of gravity separation column 11.

[0044] Preferably, a thickener is also provided between the first-stage gravity separator, the second-stage gravity separator, the third-stage gravity separator and the magnetic separator. A thickener 4 is provided between the first-stage gravity separator and the second-stage gravity separator, a thickener 8 is provided between the second-stage gravity separator and the third-stage gravity separator, and a thickener 12 is provided between the third-stage gravity separator and the magnetic separator.

[0045] Preferably, the concentrate outlets of the first-stage gravity separator, the second-stage gravity separator, the third-stage gravity separator, and the magnetic separator are all connected to the concentrate collection box, and a #4 thickener 15 and a #1 filter press 14 are sequentially installed in front of the inlet of the concentrate collection box.

[0046] Preferably, the tailings outlets of the first-stage gravity separator, the second-stage gravity separator, the third-stage gravity separator, and the magnetic separator are all connected to the tailings collection box, and a No. 5 thickener 17 and a No. 2 filter press 16 are sequentially installed in front of the inlet of the tailings collection box.

[0047] Example 2:

[0048] A beneficiation method for enriching fine-grained, low-grade ilmenite from titanium tailings:

[0049] S1. Fine-grained, low-grade ilmenite feedstock is pumped into hydrocyclone 1 (No. 1) at a feed concentration of 5%-20% and a feed pressure of 0.10-0.20 MPa for classification. The overflow from classification 1 proceeds to step S2. The underflow from classification 1 is replenished with water to a mass concentration of 35% and pumped into gravity separation column 2 (No. 1). The underflow from classification 1 is predominantly composed of +75 micrometer particles, accounting for over 85%. The particle size distribution and metal distribution of the raw ore are shown in Table 1, and the gravity separation results of the underflow from classification 1 are shown in Table 2.

[0050] Table 1: Particle size distribution and metal distribution of raw ore

[0051]

[0052] Table 2: Results of the Staged Bottom Flow Reselection Experiment 1

[0053]

[0054] The concentrate obtained after separation by the No. 1 gravity separation column has a relatively high grade compared to the feed, but its liberation degree is still poor. Therefore, concentrate 1 is returned to the feed after grinding. Step S1 is mainly used to remove gangue minerals of the +75 micrometer coarse size.

[0055] The fractional overflow 1 generated in S2 and S1 is concentrated to a mass concentration of approximately 15% by thickener 4 (#1) and then pumped into hydrocyclone 5 (#2) at a pressure of 0.10-0.20 MPa. The resulting fractional underflow 2 is predominantly -75 to +38 micrometers, accounting for over 80%. After adjusting the fractional underflow 2 to a mass concentration of 30%, it is pumped into gravity separation column 6 (#2). The experimental results are shown in Table 3.

[0056] Table 3: Results of coarse separation experiments in staged bottom current 2nd reselection

[0057]

[0058] After the rough concentrate 1 of gravity column 6 was adjusted to a mass concentration of 30%, it was pumped into gravity column 7 of gravity column 3. The experimental results are shown in Table 4.

[0059] Table 4: Results of gravity separation and cleaning experiments for rough concentrate 1

[0060]

[0061] Therefore, the product properties obtained in step S2 are shown in Table 5:

[0062] Table 5: Properties of the final product from step S2

[0063]

[0064] S3, the staged overflow 2 generated in S2 is concentrated to a mass concentration of about 10% by thickener 8 (#2), and then pumped into gravity separator 9 (#4). The flow velocity of the water in gravity separator 9 is adjusted to 0.043 cm / s, the stirring speed is 350 r / min, and the throughput is 0.23 t / (m³). 2 The results of the reselection column grading experiment are shown in Tables 6 and 7 below.

[0065] Table 6: Properties of Graded Bottom Flow 3 Products

[0066]

[0067] Table 7: Product Properties of Graded Overflow 3

[0068]

[0069] The fractional underflow 3 generated by the No. 4 gravity separation column 9 was adjusted to a mass concentration of 30% and then pumped into the No. 5 gravity separation column 10. The results of the roughing experiment are shown in Table 8 below.

[0070] Table 8: Results of coarse separation experiments in staged bottom current triple separation

[0071]

[0072] After the rough concentrate 2 from column 5# 10 was adjusted to a mass concentration of 30%, it was pumped into column 6# 11. The results of the fine separation experiment are as follows: 9.

[0073] Table 9: Results of the secondary separation and refining experiments for rough and concentrate ore

[0074]

[0075]

[0076] Therefore, the product properties obtained from step S3 are shown in Table 10:

[0077] Table 10: Properties of the final product from step S3

[0078]

[0079] S4 and the graded overflow 3 generated in S3 are concentrated by thickener 12 to a mass concentration of about 15%, and then pumped into magnetic separator 9. The magnetic field strength is adjusted to 22kOe. The results of the magnetic separation experiment are shown in Table 11 below.

[0080] Table 11: Results of S4 Strong Magnetic Separation Experiment

[0081]

[0082] Finally, the products from S1, S2, S3, and S4 were combined, and the properties of the final concentrate and tailings products are shown in Table 12 below.

[0083] Table 12: Properties of Final Products

[0084]

[0085] Finally, concentrates 2, 3 and 4 are discharged into the concentrate thickener, namely thickener 4#15. After thickening, the sediment 4 is dewatered by filter press 1#14 to become the final concentrate product with low moisture content, high grade and uniform particle size.

[0086] The tailings 1-6 are discharged into the tailings thickener, namely thickener 5# 17. The thickened sediment 5 is dewatered by filter press 2# 16 to become an environmentally friendly tailings product that does not contain mineral processing reagents.

Claims

1. A beneficiation device for enriching fine-grained low-grade ilmenite from ilmenite tailings, characterized by, The first stage of reselection device, the second stage of reselection device, the third stage of reselection device and magnetic separation device, the overflow port of the first stage of reselection device is connected with the feeding port of the second stage of reselection device, the overflow port of the second stage of reselection device is connected with the feeding port of the third stage of reselection device, the overflow port of the third stage of reselection device is connected with the feeding port of the magnetic separation device, the first stage of reselection device comprises a 1# cyclone (1), a 1# reselection column (2) and a grinding machine (3), the second stage of reselection device comprises a 2# cyclone (5), a 2# reselection column (6) and a 3# reselection column (7), the third stage of reselection device comprises a 4# reselection column (9), a 5# reselection column (10) and a 6# reselection column (11), the magnetic separation device comprises a strong magnetic separator (13), in the first stage of reselection device, the underflow port of the 1# cyclone (1) is connected with the feeding port of the 1# reselection column (2), the underflow port of the 1# reselection column (2) is connected with the feeding port of the grinding machine (3), the grinding machine (3) is connected with the feeding port of the 1# cyclone (1) through a backflow device, in the second stage of reselection device, the underflow port of the 2# cyclone (5) is connected with the feeding port of the 2# reselection column (6), the underflow port of the 2# reselection column (6) is connected with the feeding port of the 3# reselection column (7), in the third stage of reselection device, the underflow port of the 4# reselection column (9) is connected with the feeding port of the 5# reselection column (10), the underflow port of the 5# reselection column (10) is connected with the feeding port of the 6# reselection column (11), the concentrate discharge ports of the second stage of reselection device, the third stage of reselection device and the magnetic separation device are connected with a concentrate collection box, a 4# thickener (15) and a 1# filter press (14) are sequentially arranged in front of the feeding port of the concentrate collection box.

2. The ore dressing device according to claim 1, characterized in that, A thickener is arranged between the first stage of reselection device, the second stage of reselection device, the third stage of reselection device and the magnetic separation device, a 1# thickener (4) is arranged between the first stage of reselection device and the second stage of reselection device, a 2# thickener (8) is arranged between the second stage of reselection device and the third stage of reselection device, and a 3# thickener (12) is arranged between the third stage of reselection device and the magnetic separation device.

3. The ore dressing device according to claim 1, characterized in that, The concentrate discharge ports of the first stage of reselection device, the second stage of reselection device, the third stage of reselection device and the magnetic separation device are connected with a tailing collection box, a 5# thickener (17) and a 2# filter press (16) are sequentially arranged in front of the feeding port of the tailing collection box.

4. A beneficiation method using the beneficiation device for enriching fine-grained low-grade ilmenite from tailings of ilmenite selection according to claim 1, characterized in that, The method comprises the following steps: S1, coarse particle enrichment and waste rejection: the fine particle low-grade ilmenite raw material is subjected to first-stage classification treatment to obtain a classification underflow 1 and a classification overflow 1, and the obtained classification underflow 1 is ground and then subjected to first-stage classification treatment again; S2, medium particle enrichment and waste rejection: the classification overflow 1 is subjected to second-stage classification treatment to obtain a classification underflow 2 and a classification overflow 2, the classification underflow 2 is subjected to two times of reselection, namely, rough selection and fine selection, the concentrate product of the rough selection is subjected to fine selection again, and finally obtained concentrate 2 enters a final concentrate product; S3, fine particle enrichment and waste: the overflow 2 is subjected to third stage classification to obtain the underflow 3 and the overflow 3, the underflow 3 is subjected to two times of separation by gravity separation, which are roughing and cleaning, the concentrate of the roughing is subjected to re-cleaning, and the concentrate 3 is obtained and enters the final concentrate product; S4, slime recovery: the overflow 3 is subjected to magnetic separation, and the concentrate 4 is obtained and enters the final concentrate product.

5. The beneficiation method according to claim 4, characterized in that, The grinding of the underflow 1 in step S1 is to grind the titanium ore sample to more than 90% of the particle size of-75 μm, and then mix the raw material to perform classification treatment.

6. The beneficiation method according to claim 4, characterized in that, The grinding in step S1 is performed by using a grinding device, and the feeding concentration of the grinding device is 20%-40%.

7. The beneficiation method according to claim 4, characterized in that, The magnetic separation in step S4 is performed by using a high-intensity magnetic separation device, and the magnetic field strength of the high-intensity magnetic separation device is 10-24 kOe.

8. The beneficiation method of claim 4, wherein, The classification treatment in steps S1 and S2 is performed by using a cyclone, and the feeding concentration of the cyclone is 5%-20%, and the feeding pressure is 0.10-0.20 MPa.

9. The beneficiation method according to claim 4, characterized in that, The underflow 1, the underflow 2 and the underflow 3 obtained by the classification treatment in steps S1, S2 and S3 are subjected to gravity separation, and the gravity separation device is a countercurrent gravity separation column.

10. The beneficiation method of claim 4, wherein, The tailings obtained after the treatments in steps S1, S2, S3 and S4 are subjected to dehydration treatment, and then enter the final tailings product; the concentrates 2, 3 and 4 obtained in steps S2, S3 and S4 are subjected to dehydration treatment, and then form the final concentrate product; and the clear waste liquid produced by the dehydration treatment is used for gravity separation.

11. The beneficiation method according to claim 4, characterized in that, The particle size of the underflow 1 obtained by the first stage classification is more than 85% of the particle size of +75 μm; The particle size of the underflow 2 obtained by the second stage classification is more than 80% of the particle size of-75+38 μm; The particle size of the underflow 3 obtained by the third stage classification is more than 70% of the particle size of-38+10 μm.

Images