A method for pre-concentration of low-grade stone coal vanadium ore

Abstract

The present application relates to a kind of low-grade stone coal vanadium ore pre-enrichment method, take low-grade stone coal vanadium ore after the following steps and tailings are pre-enriched to obtain vanadium concentrate, and tailings: (1) crushing: low-grade stone coal vanadium ore is crushed;(2) grinding: the undersize product in (1) is mixed with water, input into ball mill and ground;(3) slurry preparation: ore particles are fully dispersed;(4) superconducting magnetic separation;Magnetic separation produces, magnetic product and non-magnetic product;Wherein, magnetic product is the magnetic vanadium-containing mineral particles, and is the first concentrate product;(5) sedimentation classification: the non-magnetic product obtained by superconducting magnetic separation in (4) is subjected to sedimentation classification, and vanadium-containing minerals are further recovered;The first concentrate product in (4) is combined with the second concentrate product in (5) together, as pre-enriched vanadium-containing concentrate.The present application fully realizes vanadium ore pre-enrichment, and the grade of vanadium-containing concentrate is greatly improved;And the recovery rate of vanadium ore is higher.

Description

Technical Field

[0001] This invention relates to a beneficiation method for enriching valuable vanadium in vanadium shale ore, and particularly to a highly efficient beneficiation method for recovering valuable vanadium from low-grade iron-bearing vanadium shale ore with weak or extremely weak magnetic properties and fine particle embedding through superconducting magnetic separation pre-enrichment and sedimentation classification. Background Technology

[0002] Vanadium has a wide range of applications and is often referred to as the "MSG of modern industry," finding extensive use in steel, non-ferrous alloys, chemicals, new energy, and pharmaceuticals. Vanadium is distributed quite dispersedly in the Earth's crust, exhibiting a strong association with other metals, and possesses a significant affinity for siderogenation and a tendency to form components in biological bodies. Therefore, it is often found in low-grade forms in vanadium-titanium magnetite and black shale. Vanadium occurs in two forms: one is associated with other metallic minerals, such as iron, copper, lead, and titanium; the other is in vanadium-bearing clay minerals and phosphate deposits. Vanadium-bearing aluminosilicates (represented by mica) are the main carrier minerals of vanadium and are also the target minerals for pre-enrichment in mineral processing. The inorganic mineral components in vanadium shale coal deposits are mainly quartz, mica-like minerals, clay minerals, calcite, etc., and sometimes also contain pyrite and iron oxides. Among these, mica-like minerals and iron oxides (rare) are vanadium-bearing phases, while the others generally do not contain vanadium (and are the main targets for tailings removal and impurity removal during mineral processing pre-enrichment). Valence state analysis of vanadium in coal shale shows that V (vanadium) exists in trivalent, tetravalent, and pentavalent states, with the vast majority existing in trivalent form in aluminosilicate minerals such as vanadium-bearing mica, tourmaline, and garnet. Its general formula can be written as: (K,Al,V)2[AlSi3O10](OH).

[0003] Vanadium shale ore varies in origin and characteristics, resulting in significant differences in its beneficiation potential. Existing pre-enrichment processes suffer from the following problems: (1) poor general applicability and complex processes; (2) low vanadium recovery and limited enrichment; (3) conventional flotation reagents are insufficient to meet the requirements of mineral processing pre-enrichment. Although the mineral composition of vanadium shale ore varies considerably in China, their occurrence states are basically the same. Therefore, pre-enrichment work can be carried out based on the common characteristics of their process mineralogical properties, taking advantage of these differences. To address this challenge, many mineral processing researchers both domestically and internationally have conducted extensive research on the pre-enrichment of vanadium shale ore. While some progress has been made, no breakthrough has been achieved.

[0004] Therefore, it is necessary to design a pre-enrichment method for vanadium ore, especially for large quantities of low-grade vanadium ore, to improve the enrichment effect, that is, to increase the recovery rate and the concentrate yield. Summary of the Invention

[0005] The purpose of this invention is to provide a method for pre-enriching low-grade vanadium shale coal, in order to address the shortcomings of existing technologies, solve the technical problems of pre-enrichment of vanadium shale coal, effectively increase the V2O5 grade of subsequent feed materials, and improve the beneficiation index of vanadium shale coal.

[0006] To achieve the above-mentioned objectives, this invention provides a method for pre-enriching low-grade vanadium-bearing shale coal, which involves pre-enriching low-grade vanadium-bearing shale coal through the following steps to obtain vanadium-bearing concentrate and tailings:

[0007] (1) Crushing: Crushing low-grade vanadium shale coal ore;

[0008] The crushed product is screened using a standard sieve, and the product on the sieve is crushed again.

[0009] The undersized products are transferred to the next process.

[0010] (2) Grinding: Mix the undersize product from (1) with water and feed it into a ball mill for grinding;

[0011] The fineness of the product after grinding is controlled between 50% and 90% based on a standard sieve with a mesh size of 200 mesh or -0.074 mm.

[0012] (3) Slurry preparation: The grinding product of (2) is prepared by stirring with a stirrer, and the slurry concentration is controlled at 20% to ensure that the ore particles are fully dispersed;

[0013] (4) Superconducting magnetic separation: The slurry with fully dispersed ore particles after (3) slurry preparation is fed into a vertical superconducting magnetic separator by adding a certain amount of water and controlling the magnetic separation concentration to 5% to 15%.

[0014] The background magnetic field strength of the superconducting magnetic separator is 2T to 4T;

[0015] The products after magnetic separation are magnetic and non-magnetic products;

[0016] Among them, the magnetic product is magnetic vanadium-containing mineral particles, which is the first concentrate output.

[0017] Non-magnetic products include vanadium-free gangue and non-magnetic gangue particles containing a small amount of vanadium.

[0018] (5) Sedimentation and classification: The non-magnetic products obtained by the superconducting magnetic separator in (4) are subjected to sedimentation and classification in order to further recover vanadium-containing minerals in the vanadium-bearing shale coal mine.

[0019] The non-magnetic product produced in (4) is slurried, a dispersant is added, the slurry concentration for sedimentation and classification is controlled at 3% to 7%, and the solid is stirred to fully disperse in the slurry;

[0020] After stirring, allow to settle.

[0021] At this time, the vanadium-bearing ore particles settle slowly in the aqueous solution and will be suspended in the slurry in large quantities;

[0022] Other gangue minerals will settle rapidly in aqueous solution;

[0023] After the vanadium-bearing ore particles are separated from other gangue minerals, the vanadium-bearing ore particles that are still suspended and dispersed in the slurry are discharged with the aqueous solution. The discharged aqueous solution is then dehydrated to form vanadium-bearing concentrate, which is the second concentrate product.

[0024] The sedimentation product is a product containing no vanadium or very low vanadium, and is used as tailings.

[0025] The first concentrate product in (4) and the second concentrate product in (5) are combined together to form the pre-enriched vanadium concentrate.

[0026] As a further improvement of the present invention, in step (1) above, a jaw crusher is used to crush the blocky ore;

[0027] The standard sieve used for screening has a mesh size of 2-4 mm.

[0028] As a further improvement of the present invention, in step (2) above, after the screened product is mixed with water, the concentration is controlled to be 67%;

[0029] The water-mineral mixture is fed into an XMQ-240×90 conical ball mill for grinding;

[0030] Grinding causes the dissociation of vanadium-bearing minerals from gangue mineral particles.

[0031] As a further improvement of the present invention, in step (3) above, the mixing time for slurry preparation is greater than or equal to 5 minutes.

[0032] Furthermore, in step (3) above, a dispersant is added during the slurry preparation process;

[0033] The dispersant is water glass or sodium hexametaphosphate.

[0034] Furthermore, in step (3) above, the amount of water glass used is 500-1000 g / t; or the amount of sodium hexametaphosphate used is 200-500 g / t.

[0035] As a further improvement of the present invention, in step (4) above, the superconducting magnetic separator is a JM series superconducting magnetic separator.

[0036] Furthermore, in step (4) above, the slurry flow rate fed into the superconducting magnetic separator needs to be controlled at 1.5 to 2.5 cm / s to ensure uniform feeding;

[0037] The magnetic medium for a superconducting magnetic separator requires the selection of a wire mesh, and the mesh size can be selected from any of the following sizes: 2×4mm, 3×6mm, 4×8mm, 6×10mm, or 7×12mm.

[0038] As a further improvement of the present invention, in step (5) above, the dispersant is sodium hexametaphosphate, and the dosage is 1000-3000 g / t;

[0039] After adding the dispersant to the slurry, the stirring intensity is 800-1200 rpm, and the stirring time is greater than or equal to 5 min;

[0040] After stirring, allow the mixture to settle for 5 to 8 minutes.

[0041] This invention discloses a method for pre-enriching low-grade vanadium ore in shale coal. Targeting the characteristics of vanadium ore in low-grade shale coal, the method first crushes and grinds the shale coal to fully dissociate the vanadium-bearing minerals from the gangue mineral particles, obtaining ore powder. Then, a slurry is prepared to fully disperse the vanadium-bearing mineral particles and gangue mineral particles in an aqueous solution. Next, superconducting magnetic separation is performed, utilizing a strong magnetic field of 2T to 4T to fully adsorb the weakly magnetic vanadium-bearing magnetic particles of limonite and vanadium mica, forming magnetic vanadium-bearing mineral particles, which constitute the first concentrate product. The non-magnetic product after superconducting magnetic separation is then subjected to sedimentation classification. Taking advantage of the slow settling speed of vanadium-bearing mineral particles in aqueous solution, it is separated from other gangue minerals to obtain the second concentrate product, significantly improving the recovery rate of vanadium ore concentrate. Finally, the first and second concentrate products are combined to form the target pre-enriched vanadium-bearing concentrate of this invention.

[0042] This invention discloses a pre-enrichment method for low-grade vanadium shale coal ore. The method rationally designs a pre-enrichment approach for low-grade vanadium shale coal ore, fully realizing vanadium ore pre-enrichment and significantly improving the grade of vanadium-bearing concentrate. This meets the quality requirements of subsequent metallurgical operations for vanadium extraction raw materials and allows for the disposal of a large amount of tailings, reducing the amount of ore entering the metallurgical process and enabling subsequent smelting to obtain high-quality metallic vanadium. Furthermore, this method achieves a high vanadium ore recovery rate, avoiding the waste of vanadium ore resources. Attached Figure Description

[0043] Figure 1 This is a schematic diagram of the process flow for a pre-enrichment method for low-grade vanadium shale coal according to the present invention. Detailed Implementation

[0044] The specific embodiments of the present invention will be further described in detail below with reference to the accompanying drawings. The embodiments are merely illustrative of the present invention, and the content of the present invention is not limited to the following embodiments.

[0045] This invention is a method for pre-enriching low-grade vanadium shale coal, using Shaanxi vanadium shale coal as raw material and introducing superconducting magnetic separation to pre-enrich the vanadium ore.

[0046] The vanadium-bearing shale mines in Shaanxi Province are mainly argillaceous rock-type coal. Vanadium is primarily found in vanadium-bearing mica and limonite. Limonite exhibits relatively strong magnetism compared to vanadium-bearing mica, displaying only weak magnetism, while the vanadium-bearing mica exhibits extremely weak magnetism. Conventional magnetic separation methods, due to their magnetic field strength not exceeding 1.8T, cannot achieve satisfactory enrichment and recovery. Therefore, superconducting magnetic separation equipment has been introduced, which can provide magnetic fields exceeding 1.8T, up to 8T or even higher. This allows for the magnetic separation of vanadium-bearing minerals with weak and extremely weak magnetism in the ore. Superconducting magnetic separation, with its high background magnetic field strength, can effectively recover dissociated weakly magnetic minerals, achieving highly efficient enrichment of the target mineral. The background magnetic induction intensity of superconducting equipment can reach over 3T, providing a high magnetic field force for the recovery of fine-grained weakly magnetic minerals. It features good stability, high separation efficiency, low operating power, and high utilization rate.

[0047] The present invention discloses a method for pre-enriching low-grade vanadium shale coal, comprising the following steps:

[0048] Vanadium shale ore is crushed and screened to below 3mm using a crusher, followed by grinding and liberation. The ground slurry is then stirred and sized. Depending on the ore properties, dispersants such as water glass and sodium hexametaphosphate can be added during the slurry slurry slurry slurry slurry preparation. The slurry is then fed into a vertical superconducting magnetic separator by pump or manual operation for superconducting magnetic separation under a specific high magnetic field strength. This process yields a magnetic vanadium-containing product and a non-magnetic product, mainly composed of gangue such as clay and quartz, which contains a small amount of vanadium. Finally, the non-magnetic product is subjected to sedimentation and classification to further recover vanadium-containing mineral particles and improve the recovery efficiency of the valuable element vanadium.

[0049] The present invention discloses a method for pre-enriching low-grade vanadium shale coal, the specific steps of which are as follows:

[0050] (1) Crushing: Jaw crusher is used to crush block ore. The crushed products are screened using a standard screen. The products on the screen are returned to the jaw crusher for further crushing until all the crushed products of the crusher pass through the screen holes of the standard screen and become the undersize products.

[0051] In step 1(1), the standard sieve used for sieving has a sieve aperture of 2 to 4 mm.

[0052] (2) Grinding: Mix the undersize product from (1) with water, control the concentration to 67%, and feed it into the XMQ-240×90 conical ball mill for grinding, so as to achieve the separation of vanadium-containing minerals and gangue minerals in the ore, in order to carry out superconducting magnetic separation enrichment in the future.

[0053] In this step, the grinding concentration is 67%, and the fineness of the grinding product is controlled to be between 50% and 90% using a standard sieve with a mesh size of 200 mesh or -0.074 mm. If the grinding product particle size is too coarse, on the one hand, vanadium-containing mineral particles and gangue mineral particles cannot be completely separated, resulting in very low or no separation efficiency of the superconducting magnetic separation, that is, there is no significant difference in vanadium content between non-magnetic products or magnetic products and non-magnetic products; on the other hand, if the grinding product particle size is too coarse, it will also clog the superconducting magnetic separation medium during the superconducting magnetic separation process, causing the superconducting magnetic separator to malfunction. If the grinding product particle size is too fine, on the one hand, it will cause the already separated vanadium-containing mineral particles and gangue mineral particles to become even finer, i.e., over-grinding. The finer the vanadium-containing mineral particles, the weaker their magnetism, which is not conducive to superconducting magnetic separation. Correspondingly, the finer the gangue mineral particles, the easier they are to muddy and adhere to the surface of the vanadium-containing mineral particles, affecting the quality of the magnetic products from superconducting magnetic separation. On the other hand, if the grinding product particle size is too fine, the vanadium-containing mineral particles will be subjected to greater impact force from the water flow during superconducting magnetic separation, making them more likely to enter the non-magnetic products with the water flow, resulting in lower separation efficiency of the superconducting magnetic separator and lower vanadium magnetic separation recovery rate.

[0054] (3) Slurry preparation: The grinding product of (2) is prepared by conventional agitator. The slurry concentration is controlled at 20% and the stirring time is 5 minutes. The purpose is to ensure that the vanadium-containing mineral particles and gangue mineral particles are fully dispersed in the aqueous solution. Sometimes, depending on the needs, dispersants such as water glass and sodium hexametaphosphate are added during the slurry preparation process. The amount of water glass is 500-1000 g / t and the amount of sodium hexametaphosphate is 200-500 g / t.

[0055] (4) Superconducting magnetic separation: The slurry after (3) slurry preparation, in which the ore particles are fully dispersed, is fed into a vertical superconducting magnetic separator by adding a certain amount of water and controlling the magnetic separation concentration to 5% to 15%. The magnetic products are magnetic vanadium-containing mineral particles, and the non-magnetic products are gangue without vanadium and non-magnetic gangue particles containing a small amount of vanadium. These are used as feed for sedimentation and classification to further recover the non-magnetic vanadium-containing mineral particles and improve the vanadium recovery rate.

[0056] In this step, the superconducting magnetic separator used is the JM series superconducting magnetic separator from Jiangsu Jingkai Zhongke Superconducting High-Tech Co., Ltd.

[0057] The feed concentration for superconducting magnetic separation is controlled between 5% and 15%. If the concentration is too high, the probability of collision between particles will increase significantly during the superconducting magnetic separation process. Under the influence of magnetic force and magnetic medium, inclusions are likely to occur, bringing useless mineral particles such as gangue into the magnetic product and affecting the vanadium content in the magnetic product. If the concentration is too low, the proportion of ore particles in the unit volume of slurry is small. They are easily lost in the non-magnetic product due to the impact of water flow and not being captured by magnetic force in time, resulting in a low yield of magnetic products and a low vanadium recovery rate.

[0058] The slurry flow rate fed into the superconducting magnetic separator needs to be controlled between 1.5 and 2.5 cm / s, and the ore should be fed evenly. Similar to the ore concentration, the feed rate should not be too fast or too slow. If the feed rate is too fast, the magnetic particles cannot be captured by the magnetic force generated by the magnetic separator in time and will be lost in the non-magnetic products. If the feed rate is too slow, the impact force of the water flow is too weak, and the ore particles are easily adsorbed on the magnetic medium of the magnetic separator and block the magnetic separation channel, resulting in a significant reduction in the quality of the magnetic products.

[0059] The magnetic medium for superconducting magnetic separators requires the selection of wire mesh, with mesh sizes such as 2×4mm, 3×6mm, 4×8mm, 6×10mm, and 7×12mm, matching the fineness of the grinding product. The coarser the grinding product, the coarser the wire mesh size should be, and vice versa. However, the mesh size cannot be too coarse or too fine. Finer mesh sizes are more prone to clogging the magnetic separation channels of the superconducting magnetic separator, leading to severe inclusion issues. Larger mesh sizes result in weaker magnetic forces on ore particles within the superconducting magnetic separator, making them less likely to be captured and lost in the non-magnetic product.

[0060] The background magnetic field strength of a superconducting magnetic separator needs to reach above 2T, with a suitable range of 2-4T. It should be noted that since the vanadium-containing magnetic particles are limonite and vanadium mica, which have very weak magnetism, the background magnetic field strength of ordinary magnetic separators can only reach a maximum of 1.8T, which cannot effectively recover the above-mentioned ore particles. Therefore, a magnetic separator with a higher magnetic field strength is required, which can only be a superconducting magnetic separator. At the same time, the background magnetic field strength cannot be too high. If the magnetic field strength is too high, some gangue minerals that do not contain vanadium have extremely weak magnetism and will be captured by the superconducting magnetic separator and enter the magnetic product, thereby affecting the vanadium quality in the magnetic product.

[0061] Superconducting magnetic separation pre-enrichment can remove about 60% of the vanadium ore from shale vanadium ore powder.

[0062] (5) Sedimentation and classification: In order to further recover vanadium-bearing minerals in vanadium-bearing shale ore, especially non-magnetic vanadium-bearing mineral particles, the non-magnetic products obtained by the superconducting magnetic separator in (4) are subjected to sedimentation and classification in order to further recover vanadium-bearing minerals in vanadium-bearing shale ore.

[0063] In this step, since the non-magnetic product contains mostly clay minerals, the slurry viscosity can easily affect the sedimentation and classification effect. To ensure sufficient dispersion of clay minerals and vanadium-containing mineral particles during the sedimentation and classification process, it is necessary to adjust the slurry by adding sodium hexametaphosphate dispersant at a dosage of 1000–3000 g / t, controlling the slurry concentration for sedimentation and classification to 3%–7%, the stirring intensity to 800–1200 rpm, and the stirring time to 5 min. After stirring, the settling time is 5–8 min. At this point, the vanadium-containing minerals… Most of the mineral particles are composed of vanadium-bearing mica that is extremely fine, weakly magnetic, or non-magnetic. It is not easily captured by the magnetic force generated by the magnetic medium in a magnetic field. However, due to its fine particle size, it settles slowly in aqueous solution. Other gangue minerals, on the other hand, have a higher density and coarser particle size, and settle rapidly in aqueous solution. The vanadium-bearing mineral particles are suspended and dispersed in the slurry and can be discharged as concentrate along with the aqueous solution, which is the second product produced by this invention. The discharged slurry, after dehydration, becomes vanadium-bearing concentrate. The sedimentation product that does not contain vanadium or contains very low vanadium is called tailings.

[0064] This step, through sedimentation and classification, can separate out about 20% of the vanadium ore from the ore powder.

[0065] The superconducting magnetic separation enrichment concentrate produced in step (4) is mixed with the sedimentation and classification pre-enrichment concentrate produced in step (5) to obtain the final product, which is a vanadium-containing mixed concentrate. This can meet the quality requirements of subsequent metallurgical operations for vanadium extraction raw materials, and can also discard a large amount of tailings, reducing the amount of ore entering the metallurgical operation, so as to obtain high-quality metallic vanadium in subsequent smelting.

[0066] The above-mentioned method for pre-enriching low-grade vanadium ore from coal sand is applied to the pre-enrichment of vanadium ore from coal sand raw materials.

[0067] Example 1 The raw material is a low-grade vanadium shale coal mine in Shaanxi Province, with a V2O5 grade of 0.74% in the raw ore.

[0068] The ore with a grade of 0.74% was coarsely crushed using a jaw crusher. The crushed product was screened using a 2mm sieve, and the oversize product was returned to the jaw crusher for further crushing until all crushed products could pass through the 2mm sieve. The crushed product was then processed by a ball mill to reduce the particle size to -0.074mm (70%). The operating parameters of the superconducting magnetic separator were adjusted as follows: background magnetic induction intensity of 4T, slurry concentration of 10%, magnetic media of 7*12 steel mesh, and slurry flow rate of 2cm / s. After one superconducting magnetic separation, the concentrate yield was 17.99%, the grade was 2.38%, and the recovery rate was 60.97%. The tailings processed by the superconducting magnetic separator continued to undergo settling, with the operating conditions adjusted as follows: concentration of 5%, dispersant of 2000g / t, strong stirring for 20min, and settling for 7min. A mixed concentrate was obtained.

[0069] The results of the mineral processing test are shown in Table 1:

[0070] Table 1. Separation results of superconducting-sedimentation process in a coal-vanadium mine in Shaanxi Province

[0071] Superconducting concentrate 17.99 2.38 59.28 Settled concentrate 7.83 0.91 9.81 Total concentrate 25.82 1.93 69.09 Tailings 74.18 0.30 30.91 raw ore 100 0.72 100

[0072] Pre-enriched concentrate parameters: concentrate yield 30%, V₂O₅ grade in concentrate 1.933%, recovery rate 69.08%, enrichment ratio of this process 2.38, waste disposal rate 74.18%.

[0073] Example 2 The raw material is a weathered coal-vanadium mine in Shangluo, Shaanxi Province, with a V2O5 grade of 0.504%.

[0074] Jaw crushers were used for coarse crushing. The crushed product was screened using a 2mm sieve, and the oversize product was returned to the jaw crusher for further crushing until all the crushed product could pass through the sieve. The crushed product was then processed by a ball mill to a particle size of -0.074mm (80%). The operating parameters of the superconducting magnetic separator were adjusted as follows: background magnetic induction intensity 4T, slurry concentration 10%, magnetic media 4×8 steel mesh, and slurry flow rate 2cm / s. After one superconducting magnetic separation, the concentrate yield was 21.17%, the grade was 1.44%, and the recovery rate was 57.29%. The tailings treated by the superconducting magnetic separator underwent further settling, with the operating conditions adjusted as follows: concentration 5%, dispersant 2000g / t, strong stirring for 20min, and settling for 5min. A mixed concentrate was obtained.

[0075] The results of the mineral processing test are shown in Table 2:

[0076] Table 2. Separation results of superconducting-sedimentation process in a weathered petroleum vanadium mine in Shaanxi Province.

[0077] Superconducting concentrate 21.17 1.44 57.29 Settled concentrate 19.81 0.60 22.19 Total concentrate 40.98 1.03 79.48 Tailings 59.02 0.19 20.52 raw ore 100 0.53 100

[0078] Pre-enriched concentrate parameters: concentrate yield 40.98%, V₂O₅ grade 1.032%, recovery rate 79.48%. The enrichment ratio for this process is 2.05, and the waste disposal rate is 59.02%.

[0079] The preferred embodiments of the present invention have been described in detail above, but the present invention is not limited to the embodiments described. Those skilled in the art can make various equivalent modifications or substitutions without departing from the spirit of the present invention, and these equivalent modifications or substitutions are all included within the scope defined by the claims of this application.

Claims

1. A method for pre-enriching low-grade vanadium shale coal, characterized in that, Low-grade vanadium-bearing shale coal is pre-enriched through the following steps to obtain vanadium-bearing concentrate and tailings: (1) Crushing: Crushing low-grade vanadium shale coal ore; The crushed product is screened using a standard sieve, and the product on the sieve is crushed again. The undersized products are transferred to the next process. (2) Grinding: Mix the undersize product from (1) with water and feed it into a ball mill for grinding; The fineness of the product after grinding is controlled at 50% to 90% based on a standard sieve with a mesh size of 200 mesh or -0.074 mm. (3) Slurry preparation: The grinding product of (2) is prepared by stirring with a stirrer, and the slurry concentration is controlled at 20% to ensure that the ore particles are fully dispersed; (4) Superconducting magnetic separation: The slurry with fully dispersed ore particles after (3) slurry preparation is fed into a vertical superconducting magnetic separator by adding a certain amount of water to control the magnetic separation concentration to 5%~15%. The background magnetic field strength of the superconducting magnetic separator is 2T~4T; The products after magnetic separation are magnetic and non-magnetic products; Among them, the magnetic product is magnetic vanadium-containing mineral particles, which is the first concentrate output. Non-magnetic products include vanadium-free gangue and non-magnetic gangue particles containing a small amount of vanadium. (5) Sedimentation classification: The non-magnetic products obtained by the superconducting magnetic separator in (4) are subjected to sedimentation classification in order to further recover vanadium-containing minerals in the vanadium shale coal mine; The non-magnetic product produced in (4) is slurried, a dispersant is added, the slurry concentration for sedimentation and classification is controlled at 3%~7%, and the solid is stirred to fully disperse in the slurry; After stirring, allow to settle. At this time, the vanadium-bearing ore particles settle slowly in the aqueous solution and will be suspended in the slurry in large quantities; Other gangue minerals will settle rapidly in aqueous solution; After the vanadium-bearing ore particles are separated from other gangue minerals, the vanadium-bearing ore particles that are still suspended and dispersed in the slurry are discharged with the aqueous solution. The discharged aqueous solution is then dehydrated to form vanadium-bearing concentrate, which is the second concentrate product. The sedimentation product is a product containing no vanadium or very low vanadium, and is used as tailings. The first concentrate product in (4) and the second concentrate product in (5) are combined together to form the pre-enriched vanadium-containing concentrate. In step (3) above, a dispersant is added during the slurry preparation process; the dispersant is water glass or sodium hexametaphosphate; In step (4) above, the slurry flow rate fed into the superconducting magnetic separator needs to be controlled at 1.5~2.5cm / s, and the ore should be fed evenly. The magnetic medium for a superconducting magnetic separator requires the selection of a wire mesh, and the mesh size can be selected from any of the following sizes: 2×4mm, 3×6mm, 4×8mm, 6×10mm, or 7×12mm.

2. The method for pre-enriching low-grade vanadium shale coal as described in claim 1, characterized in that, In step (1) above, a jaw crusher is used to crush the blocky ore; The standard sieve used for screening has a mesh size of 2~4mm.

3. The method for pre-enriching low-grade vanadium shale coal as described in claim 1, characterized in that, In step (2) above, after the screened product is mixed with water, the concentration is controlled at 67%; The water-mineral mixture is fed into an XMQ-240×90 conical ball mill for grinding; Grinding causes the dissociation of vanadium-bearing minerals from gangue mineral particles.

4. The method for pre-enriching low-grade shale coal and vanadium ore as described in claim 1, characterized in that, In step (3) above, the mixing time for slurry preparation is greater than or equal to 5 minutes.

5. The method for pre-enriching low-grade vanadium shale coal as described in claim 1, characterized in that, In step (3) above, the amount of water glass used is 500~1000g / t; or the amount of sodium hexametaphosphate used is 200~500g / t.

6. The method for pre-enriching low-grade vanadium shale coal as described in claim 1, characterized in that, In step (4) above, the superconducting magnetic separator is a JM series superconducting magnetic separator.

7. The method for pre-enriching low-grade vanadium shale coal as described in claim 1, characterized in that, In step (5) above, the dispersant is sodium hexametaphosphate, and the dosage is 1000~3000g / t; After adding the dispersant to the slurry, the stirring intensity is 800~1200 rpm, and the stirring time is greater than or equal to 5 min; After stirring, allow the mixture to settle for 5-8 minutes.

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