Method for recovering low-grade tungsten minerals in tungsten tailings
By combining multi-stage flotation and fine-tuning processes with optimized reagents, the problem of low recovery rate of tungsten tailings has been solved, achieving efficient recovery and resource utilization of low-grade tungsten minerals in tungsten tailings, with the characteristics of high recovery rate and environmental friendliness.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-02-11
- Publication Date
- 2026-04-14
AI Technical Summary
Existing technologies for recovering tungsten tailings have poor beneficiation indicators and low tungsten recovery rates, making it difficult to effectively utilize tungsten tailings resources.
A multi-stage flotation and cleaning process is adopted, including flotation desulfurization, tungsten flotation roughing, first tungsten flotation cleaning, second tungsten flotation cleaning, centrifugal cleaning and shaking table cleaning, combined with optimized flotation reagents such as alkali metal carbonates, butyl xanthate, methyl isobutyl methanol, water glass, sodium hexametaphosphate, lead nitrate, styrene-propenyl hydroxamic acid and oleic acid, to achieve efficient recovery of low-grade tungsten minerals from tungsten tailings.
It improves the grade of tungsten concentrate, realizes the efficient and comprehensive utilization of tungsten tailings resources, and has the advantages of simple process flow, environmental friendliness, and high mineral processing recovery rate.
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Figure CN121847322A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of tungsten ore beneficiation technology, specifically relating to a method for recovering low-grade tungsten minerals from tungsten tailings. Background Technology
[0002] Wolframite in my country is generally high-grade and easy to mine and process. However, due to its high density and brittleness, it is prone to over-crushing during mining and processing, resulting in a large amount of primary and secondary tungsten slime. Furthermore, long-term mining has led to increasingly severe problems of low yield, fine particle size, and mixed composition. On the other hand, while my country has large reserves of scheelite, the vast majority is low-grade, with over 80% having a grade of ≤0.4%. Its mineral composition is complex, with fine grain size, and it is mainly associated with non-ferrous and precious metals. Some gangue minerals have very similar physicochemical properties to scheelite, resulting in significant difficulties in beneficiation and large production of tungsten tailings in most Chinese scheelite mines.
[0003] Tungsten tailings are solid waste generated during the beneficiation process of tungsten ore, accounting for over 95% of the original ore. Due to limitations in traditional beneficiation technologies, most tailings contain varying amounts of tungsten minerals. Therefore, efficient recovery of tungsten tailings is crucial for improving the comprehensive utilization of tungsten resources and alleviating pressure on these resources. However, current methods for recovering tungsten tailings have poor beneficiation indicators and low tungsten recovery rates. Summary of the Invention
[0004] The purpose of this invention is to provide a method for recovering low-grade tungsten minerals from tungsten tailings. This method effectively recovers low-grade tungsten minerals from tungsten tailings, achieving good beneficiation indicators and realizing the efficient and comprehensive utilization of tungsten tailings resources. Furthermore, the method offers advantages such as a simple process flow, environmental friendliness, and high beneficiation recovery rate, providing an effective approach for the efficient utilization of tungsten tailings resources.
[0005] To achieve the above objectives, the present invention provides the following technical solution: This invention provides a method for recovering low-grade tungsten minerals from tungsten tailings, comprising the following steps: The grinding slurry of tungsten tailings is used as flotation feed to obtain a second tungsten flotation concentrate and flotation tailings. The flotation process includes: desulfurizing the grinding slurry to obtain a sulfur concentrate and a desulfurized flotation slurry; roughing the desulfurized flotation slurry to obtain flotation tailings and a tungsten rough concentrate; cleaning the tungsten rough concentrate using a first tungsten flotation to obtain a first tungsten flotation concentrate and a first middlings; and cleaning the first tungsten flotation concentrate using a second tungsten flotation to obtain a second tungsten flotation concentrate and a second middlings. The reagents for the desulfurization flotation include alkali metal carbonates, butyl xanthate, and methyl isobutyl methanol (MIBC, F2); the reagents for the roughing flotation include water glass, sodium hexametaphosphate, lead nitrate, styrene-propenyl hydroxamic acid (BCl), and oleic acid. The second tungsten flotation concentrate is centrifuged to obtain centrifuged tungsten concentrate and centrifuged tailings; The tungsten centrifugal concentrate is then subjected to shaking table cleaning to obtain tungsten concentrate and shaking table tailings.
[0006] Preferably, based on the mass of the tungsten tailings, the amount of the flotation desulfurization reagent is: 400-600 g / t of alkali metal carbonate, 90-110 g / t of butyl xanthate, and 50-70 g / t of methyl isobutyl methanol.
[0007] Preferably, the flotation desulfurization time is 5 to 15 minutes.
[0008] Preferably, based on the mass of the tungsten tailings, the amount of reagents used in the tungsten flotation roughing is: 900~110g / t of water glass, 20~40g / t of sodium hexametaphosphate, 200~400g / t of lead nitrate, 80~100g / t of styrene-propenyl hydroxamic acid, and 80~100g / t of oleic acid.
[0009] Preferably, the roughing time for tungsten flotation is 5 to 20 minutes.
[0010] Preferably, the time for the first tungsten flotation and the second tungsten flotation is 3 to 8 minutes independently.
[0011] Preferably, the ore fineness of the grinding slurry is ≥60% -0.074mm.
[0012] Preferably, the ore fineness of the grinding slurry is -0.074mm, accounting for 60-70%.
[0013] Preferably, the tungsten content in the tungsten tailings is ≤0.04 wt.%.
[0014] Preferably, the tungsten concentrate has a WO3 grade of ≥30%.
[0015] This invention provides a method for recovering low-grade tungsten minerals from tungsten tailings, comprising the following steps: using grinding slurry from tungsten tailings as flotation feed for flotation to obtain a second tungsten flotation concentrate and flotation tailings; the flotation includes: subjecting the grinding slurry to flotation desulfurization to obtain a sulfur concentrate and a desulfurized flotation slurry; subjecting the desulfurized flotation slurry to tungsten roughing flotation to obtain flotation tailings and a tungsten roughing concentrate; subjecting the tungsten roughing concentrate to first tungsten flotation cleaning flotation to obtain a first tungsten flotation concentrate and a first middlings; and further processing the first tungsten tailings into a second tungsten flotation concentrate. The flotation concentrate undergoes a second tungsten flotation process to obtain a second tungsten flotation concentrate and a second middlings. The flotation desulfurization reagents include alkali metal carbonates, butyl xanthate, and methyl isobutyl methanol (MIBC, F2). The tungsten flotation roughing reagents include water glass, sodium hexametaphosphate, lead nitrate, styrene-propenyl hydroxamic acid (BCl), and oleic acid. The second tungsten flotation concentrate is then centrifuged to obtain centrifuged concentrate and centrifuged tailings. Finally, the centrifuged concentrate is subjected to shaking table cleaning to obtain tungsten concentrate and shaking table tailings. This invention, by optimizing flotation reagents and combining centrifugal cleaning and shaking table cleaning after flotation, forms a flotation-gravity combined recovery method. This method effectively achieves the efficient recovery of low-grade tungsten minerals from tungsten tailings and obtains good beneficiation indicators (WO3 grade ≥30% in tungsten concentrate), realizing the efficient comprehensive utilization of tungsten tailings resources. Furthermore, the recovery method provided by this invention has the advantages of simple process flow, environmental friendliness, and high beneficiation recovery rate, providing an effective method for the efficient utilization of tungsten tailings resources. Attached Figure Description
[0016] Figure 1 A flowchart illustrating a method for recovering low-grade tungsten minerals from tungsten tailings, provided in an embodiment of the present invention. Detailed Implementation
[0017] This invention provides a method for recovering low-grade tungsten minerals from tungsten tailings, comprising the following steps: The grinding slurry of tungsten tailings is used as flotation feed to obtain a second tungsten flotation concentrate and flotation tailings. The flotation process includes: desulfurizing the grinding slurry to obtain a sulfur concentrate and a desulfurized flotation slurry; roughing the desulfurized flotation slurry to obtain flotation tailings and a tungsten rough concentrate; cleaning the tungsten rough concentrate using a first tungsten flotation to obtain a first tungsten flotation concentrate and a first middlings; and cleaning the first tungsten flotation concentrate using a second tungsten flotation to obtain a second tungsten flotation concentrate and a second middlings. The reagents for the desulfurization flotation include alkali metal carbonates, butyl xanthate, and methyl isobutyl methanol (MIBC, F2); the reagents for the roughing flotation include water glass, sodium hexametaphosphate, lead nitrate, styrene-propenyl hydroxamic acid (BCl), and oleic acid. The second tungsten flotation concentrate is centrifuged to obtain centrifuged tungsten concentrate and centrifuged tailings; The tungsten centrifugal concentrate is then subjected to shaking table cleaning to obtain tungsten concentrate and shaking table tailings.
[0018] In this invention, unless otherwise specified, all raw materials / components used in the preparation are commercially available products well known to those skilled in the art.
[0019] This invention uses the grinding slurry of tungsten tailings as flotation feed to obtain a second tungsten flotation concentrate and flotation tailings. The flotation process includes: desulfurizing the grinding slurry to obtain a sulfur concentrate and a desulfurized flotation slurry; roughing the desulfurized flotation slurry to obtain flotation tailings and a tungsten rough concentrate; cleaning the tungsten rough concentrate using a first tungsten flotation to obtain a first tungsten flotation concentrate and a first middlings; and cleaning the first tungsten flotation concentrate using a second tungsten flotation to obtain a second tungsten flotation concentrate and a second middlings. The reagents for the desulfurization flotation include alkali metal carbonates, butyl xanthate, and methyl isobutyl methanol (MIBC, F2); the reagents for the roughing flotation include water glass, sodium hexametaphosphate, lead nitrate, phenylpropenyl hydroxamic acid (BCl), and oleic acid.
[0020] In this invention, the first and second intermediate ore can be returned sequentially or discarded directly. The first intermediate ore obtained in this embodiment (i.e....) Figure 1 The middle mine 2) and the second middle mine (i.e. Figure 1 1) Discard the medium-sized ore directly.
[0021] In this invention, the chemical elements of the tungsten tailings include one or more of the following elements: O, Si, Al, Fe, K, Ca, F, Na, Mg, W, H, Ti, S, C, Mo, Mn, P, Cl, and Ge.
[0022] In this invention, the tungsten content in the tungsten tailings can be ≤0.04wt.%, and in the examples it can be 0.038~0.039wt.%.
[0023] In this invention, the chemical element content in the tungsten tailings can be: O 30.66~50.93 wt.%, Si 44.78~39.58 wt.%, Al 3.19~8.79 wt.%, Fe 2.02~4.10 wt.%, K 1.22~7.39 wt.%, Ca 0.96~1.66 wt.%, F 0.43~0.48 wt.%, Na 0.39~0.43 wt.%, Mg 0.36~0.62 wt.%, W 0.038~0.039 wt.%, H 0~0.17 wt.%, Ti 0.07~0.15 wt.%, S 0.05~0.11 wt.%, C 0~0.06 wt.%, Mo 0~0.03 wt.%, Mn 0.03~0.63 wt.%, P 0~0.18 wt.%, Cl 0~0.11 wt.%, Ge 0~0.07 wt.%.
[0024] In this invention, the fineness of the ore used for grinding is preferably ≥60% with a particle size of -0.074mm, and more preferably 60~70%.
[0025] In this invention, the flotation desulfurization reagent includes alkali metal carbonate, butyl xanthate, and methyl isobutyl methanol (MIBC, F2). The alkali metal carbonate can be sodium carbonate. Based on the mass of the tungsten tailings, the preferred dosage of the flotation desulfurization reagent is as follows: the alkali metal carbonate is preferably 400-600 g / t, and in the example, it can be 500 g / t. The butyl xanthate is preferably 90-110 g / t, and in the example, it can be 100 g / t. The methyl isobutyl methanol is preferably 50-70 g / t, and in the example, it can be 60 g / t.
[0026] In this invention, the flotation desulfurization time is preferably 5 to 15 minutes.
[0027] In this invention, the flotation desulfurization preferably includes: adding alkali metal carbonates to the grinding slurry for a first stirring treatment, then adding butyl xanthate for a second stirring treatment; then adding F2 for a third stirring treatment to obtain a prepared slurry; and finally performing final flotation on the prepared slurry to obtain flotation tailings and tungsten roughing concentrate. The first stirring treatment time is preferably 3-4 minutes. The second stirring treatment time is preferably 3-4 minutes. The third stirring treatment time is preferably 1-2 minutes. The final flotation time is preferably 5-6 minutes.
[0028] After obtaining the desulfurized flotation pulp, the present invention performs tungsten flotation roughing on the desulfurized flotation pulp to obtain flotation tailings and tungsten roughing concentrate. In the present invention, the reagents for the tungsten flotation roughing include water glass, sodium hexametaphosphate, lead nitrate, styrene-propenyl hydroxamic acid (BCl), and oleic acid. Based on the mass of the tungsten tailings, the preferred amounts of the reagents for the tungsten flotation roughing are as follows: water glass is preferably 900-110 g / t, and in the example, it can be 100 g / t. Sodium hexametaphosphate is preferably 20-40 g / t, and in the example, it can be 30 g / t. Lead nitrate (Pb(NO3)2) is preferably 200-400 g / t, and in the example, it can be 300 g / t. Styrene-propenyl hydroxamic acid is preferably 80-100 g / t, and in the example, it can be 90 g / t. The preferred amount of oleic acid used is 80-100 g / t, and in the example it can be 90 g / t.
[0029] In this invention, the preferred time for the tungsten flotation roughing is 5 to 20 minutes.
[0030] In this invention, the roughing flotation preferably includes: adding water glass and sodium hexametaphosphate to the desulfurized flotation slurry for a first stirring treatment, then adding lead nitrate for a second stirring treatment, then adding BCl and oleic acid for a third stirring treatment, and finally performing final flotation. The first stirring treatment time is preferably 3-4 minutes. The second stirring treatment time is 5-6 minutes. The third stirring treatment time is 3-4 minutes. The final flotation time is preferably 5-6 minutes.
[0031] In this invention, the first tungsten flotation and purification process does not use reagents, and the preferred time for the first tungsten flotation and purification process is 3 to 8 minutes, which can be 5 minutes in the embodiments.
[0032] In this invention, the second tungsten flotation and purification process does not use reagents, and the preferred time for the second tungsten flotation and purification process is 3 to 8 minutes, which can be 5 minutes in the embodiment.
[0033] After obtaining the second tungsten flotation concentrate, the present invention further refines the second tungsten flotation concentrate by centrifugal cleaning to obtain centrifugal-cleaned tungsten ore and centrifugal tailings. In this invention, the centrifugal cleaning can be carried out in a centrifugal concentrator. The preferred rotational speed of the centrifugal cleaning is 300~800 rpm.
[0034] After obtaining the centrifugal concentrate of tungsten, the present invention further refines the tungsten centrifugal concentrate using a shaking table to obtain tungsten concentrate and shaking table tailings. In the present invention, the shaking table refining can be carried out in a shaking table.
[0035] This invention achieves further separation of the second tungsten flotation concentrate obtained after flotation by sequentially performing centrifugal cleaning and shaking table cleaning, thereby improving the grade of the tungsten concentrate.
[0036] In this invention, the tungsten concentrate has a WO3 grade of ≥30%.
[0037] To further illustrate the present invention, the technical solutions provided by the present invention are described in detail below with reference to embodiments, but these should not be construed as limiting the scope of protection of the present invention. Embodiments 1 and 2 below are implemented according to… Figure 1 The flowchart shown illustrates the recovery of low-grade tungsten minerals from tungsten tailings.
[0038] Example 1: In this embodiment, the chemical elements in the tungsten tailings sample are mainly composed of O, Si, Al, Fe, and K, and also contain small amounts of H, Ti, S, C, Mo, and Mn. The chemical element composition is shown in Table 1.
[0039] Table 1. Main chemical elemental composition (wt / %) of tungsten tailings sample in Example 1
[0040] Note: The chemical elemental composition in Table 1 represents only the average value of mineral elements in the scanned area, and the detection limit is 0.01 wt / .
[0041] The flowchart of the recycling method provided in this embodiment is as follows: Figure 1 As shown. The recovery method provided in this embodiment processes 5000g of feed ore (65% of which has a grinding fineness of -0.074mm), and the specific steps are as follows: (1) Flotation desulfurization: Add 500 g / t sodium carbonate (Na2CO3) to the feed ore and stir for 3 min; then add 100 g / t butyl xanthate and stir for 3 min; then add 60 g / t F2 reagent and stir for 1 min to complete the slurry preparation. The prepared slurry is subjected to flotation for 5 min to obtain sulfur concentrate and flotation desulfurization slurry; (2) Tungsten flotation roughing: In step (1), 100 g / t water glass and 30 g / t sodium hexametaphosphate are added to the flotation desulfurized slurry and stirred for 3 min; 300 g / t Pb(NO3)2 is added and stirred for 5 min; then 90 g / t oleic acid and 90 g / t BCl reagent are added and stirred for 3 min; then tungsten roughing is carried out for 5 min to obtain flotation tailings and tungsten roughing concentrate. (3) First tungsten flotation cleaning: The tungsten roughing concentrate obtained in step (2) is cleaned for 5 minutes to obtain middlings 2 (discarded) and the first tungsten flotation concentrate; (4) Second tungsten flotation cleaning: The first tungsten flotation concentrate obtained in step (3) is cleaned for 5 minutes to obtain middle ore 1 (discarded) and the second tungsten flotation concentrate; (5) Centrifugal Concentration: The second tungsten flotation concentrate obtained in step (4) is centrifuged (in a centrifugal concentrator at a speed of 500 rpm) to obtain centrifugal tailings and centrifugal concentrate tungsten ore. (6) Shaking table refining: The tungsten centrifugal concentrate obtained in step (5) is refined by shaking table to obtain tungsten concentrate and shaking table tailings.
[0042] In this embodiment, the entire process combines multi-stage flotation (including flotation desulfurization, tungsten flotation roughing, first tungsten flotation fine selection, second tungsten flotation fine selection), fine selection (centrifugal fine selection), and gravity separation (shaking table fine selection) to achieve the separation and enrichment of tungsten and sulfur.
[0043] This embodiment is for tungsten tailings, and adopts the following method: Figure 1 The aforementioned recycling process yielded a WO3 grade of 31.05% and a recovery rate of 41.75% for tungsten concentrate.
[0044] Example 2: In this embodiment, the chemical elements in the tungsten tailings sample are mainly composed of Si, Al, K, Fe, Ca, etc., and also contain small amounts of trace elements such as Mn, Mg, F, Na, P, Cl, Ti, Ge and S. The chemical element composition is shown in Table 2.
[0045] Table 2. Main chemical elemental composition (wt.%) of tungsten tailings samples in Example 2
[0046] Note: The chemical element composition in Table 1 represents only the average value of minerals within the scanned area, and is calculated based on the standard molecular formula of the minerals.
[0047] The flowchart of the recycling method provided in this embodiment is as follows: Figure 1 As shown. The recovery method provided in this embodiment processes 5000g of feed ore (grinding fineness -0.074mm accounts for 60~70%), and the specific steps are as follows: (1) Flotation desulfurization: Add 500 g / t sodium carbonate (Na2CO3) to the feed ore and stir for 3 min; then add 100 g / t butyl xanthate and stir for 3 min; then add 60 g / t F2 reagent and stir for 1 min to complete the slurry preparation. The prepared slurry is subjected to flotation for 5 min to obtain sulfur concentrate and flotation desulfurization slurry; (2) Tungsten flotation roughing: In step (1), 100 g / t water glass and 30 g / t sodium hexametaphosphate are added to the flotation desulfurized slurry and stirred for 3 min; 300 g / t Pb(NO3)2 is added and stirred for 5 min; then 90 g / t oleic acid and 90 g / t BCl reagent are added and stirred for 3 min; then tungsten roughing is carried out for 5 min to obtain flotation tailings and tungsten roughing concentrate. (3) First tungsten flotation cleaning: The tungsten roughing concentrate obtained in step (2) is cleaned for 5 minutes to obtain middlings 2 and the first tungsten flotation concentrate; (4) Second tungsten flotation cleaning: The first tungsten flotation concentrate obtained in step (3) is cleaned for 5 minutes to obtain middlings 1 and second tungsten flotation concentrate; (5) Centrifugal Concentration: The second tungsten flotation concentrate obtained in step (4) is centrifuged to obtain centrifuged tailings and centrifuged tungsten concentrate. (6) Shaking table refining: The tungsten centrifugal concentrate obtained in step (5) is refined by shaking table to obtain tungsten concentrate and shaking table tailings.
[0048] In this embodiment, the entire process combines multi-stage flotation (including flotation desulfurization, tungsten flotation roughing, first tungsten flotation cleaning, and second tungsten flotation cleaning), cleaning (centrifugal cleaning, carried out in a centrifugal concentrator at a speed of 500 rpm) and gravity separation (shaking table cleaning) to achieve the separation and enrichment of tungsten and sulfur.
[0049] This embodiment is for tungsten tailings, and adopts the following method: Figure 1 The aforementioned recycling process yielded ore beneficiation technical indicators of 34.72% WO3 grade and 41.10% recovery rate for tungsten concentrate.
[0050] As can be seen from the above embodiments, the recovery method provided by the present invention can achieve efficient recovery of low-grade tungsten minerals in tungsten tailings. The recovery method provided by the present invention optimizes the types of flotation reagents and combines a flotation-gravity combined process with a centrifugal concentrator-shaking table for fine-grained minerals. This can effectively achieve efficient recovery of low-grade tungsten minerals in tungsten tailings and obtain ideal beneficiation indicators, realizing efficient comprehensive utilization of tungsten tailings resources. This method has the advantages of simple process, environmental friendliness, and high beneficiation recovery rate, and can provide reference and guidance for the efficient utilization of tailings resources at home and abroad.
[0051] Although the above embodiments have provided a detailed description of the present invention, they are only some embodiments of the present invention, and not all embodiments. Other embodiments can be obtained based on these embodiments without creative effort, and these embodiments all fall within the protection scope of the present invention.
Claims
1. A method for recovering low-grade tungsten minerals from tungsten tailings, characterized in that, Includes the following steps: The grinding slurry of tungsten tailings is used as flotation feed to obtain a second tungsten flotation concentrate and flotation tailings; the flotation includes: flotation desulfurization of the grinding slurry to obtain a sulfur concentrate and flotation desulfurization slurry; The desulfurized flotation slurry is subjected to tungsten flotation roughing to obtain flotation tailings and tungsten roughing concentrate; the tungsten roughing concentrate is subjected to a first tungsten flotation cleaning to obtain a first tungsten flotation concentrate and a first middlings; the first tungsten flotation concentrate is subjected to a second tungsten flotation cleaning to obtain a second tungsten flotation concentrate and a second middlings; the reagents for flotation desulfurization include alkali metal carbonates, butyl xanthate, and methyl isobutyl methanol; the reagents for tungsten flotation roughing include water glass, sodium hexametaphosphate, lead nitrate, styrene-propenyl hydroxamic acid, and oleic acid; The second tungsten flotation concentrate is centrifuged to obtain centrifuged tungsten concentrate and centrifuged tailings; The tungsten centrifugal concentrate is then subjected to shaking table cleaning to obtain tungsten concentrate and shaking table tailings.
2. The recycling method according to claim 1, characterized in that, Based on the mass of the tungsten tailings, the dosage of the flotation desulfurization reagents is as follows: 400-600 g / t of alkali metal carbonate, 90-110 g / t of butyl xanthate, and 50-70 g / t of methyl isobutyl methanol.
3. The recycling method according to claim 1 or 2, characterized in that, The flotation desulfurization time is 5-15 minutes.
4. The recycling method according to claim 1, characterized in that, Based on the mass of the tungsten tailings, the dosage of reagents used in the tungsten flotation roughing is as follows: water glass 900~110g / t, sodium hexametaphosphate 20~40g / t, lead nitrate 200~400g / t, styrene-propenyl hydroxamic acid 80~100g / t, and oleic acid 80~100g / t.
5. The recycling method according to claim 1 or 4, characterized in that, The roughing time for tungsten flotation is 5 to 20 minutes.
6. The recycling method according to claim 1, characterized in that, The time for the first tungsten flotation and the second tungsten flotation is 3 to 8 minutes independently.
7. The recycling method according to claim 1, characterized in that, The ore fineness of the grinding slurry is ≥60% -0.074mm.
8. The recycling method according to claim 7, characterized in that, The grinding slurry contains 60-70% ore with a fineness of -0.074 mm.
9. The recycling method according to claim 1, characterized in that, The tungsten content in the tungsten tailings is ≤0.04 wt.%.
10. The recycling method according to claim 1 or 9, characterized in that, The tungsten concentrate has a WO3 grade of ≥30%.