A method for comprehensive recovery of tantalum, niobium and lithium from lithium-containing ore dressing waste slag

Abstract

The present invention provides a method for comprehensively recovering tantalum, niobium and lithium from lithium-containing ore dressing waste residue, which belongs to the field of ore dressing technology. The present invention recovers coarse-grained lithium mica by screening through a high-frequency vibrating screen, recovers tantalum and niobium minerals by "spiral chute roughing-spreading chute sweeping-shaking table selection", and recovers fine-grained lithium mica by flotation method with YF2-1 as a dispersant and YP-02 as a collector, thereby realizing the comprehensive utilization of lithium-containing ore dressing waste residue and improving the level of comprehensive resource utilization. The present invention is a high-efficiency ore dressing method with low cost, good separation effect, high separation index, good stability and strong adaptability, which is suitable for promotion and application.

Description

Technical Field

[0001] The invention belongs to the technical field of mineral processing, and in particular relates to a method for comprehensively recovering tantalum, niobium and lithium from lithium-containing mineral processing waste slag. Background Art

[0002] Lithium-containing porcelain clay is one of the main lithium-containing minerals found in the earth's crust. In this ore, lithium mica is closely associated with minerals such as feldspar and quartz, and is accompanied by tantalum-niobium minerals. In the ore dressing process, gravity separation is usually used to recover tantalum-niobium minerals, and then flotation is used to recover lithium mica. For lithium mica flotation tailings, strong magnetic separation is used to remove ferromagnetic impurities to obtain ceramic raw materials with feldspar and quartz as the main components. The removed ferromagnetic impurities not only contain high lithium, but also some tantalum-niobium minerals are lost in them, resulting in serious losses of tantalum, niobium and lithium. According to statistics, the yield of this type of lithium-containing ore dressing waste is as high as 7-10%, of which the loss rate of tantalum, niobium and lithium is 8-15%, which seriously affects the efficient development and comprehensive utilization of lithium-containing porcelain clay.

[0003] The tantalum-niobium minerals in the lithium-containing ore dressing waste are finely embedded and have low monomer dissociation degree, so the direct re-selection recovery effect is poor; the lepidolite mineral flakes are large in diameter, and are easy to sink in the trough during direct flotation, and are easy to become muddy after grinding and re-selection, which affects the recovery of lepidolite; in addition, a large amount of ferromagnetic impurities and their dissolved metal ions in the ore dressing waste are easily adsorbed and covered on the surface of lepidolite, feldspar, quartz and other minerals, resulting in poor selectivity of the collector during the flotation process, making it difficult to separate the minerals from each other. At present, this type of lithium-containing ore dressing waste is usually directly disposed of as solid waste, which not only causes a waste of resources, but also the abandoned tailings will pollute the environment and have serious safety impacts.

[0004] At present, the mineral processing field generally focuses on the mineral processing and recovery of lithium mica ore, while there is very little research on the resource utilization of lithium-containing mineral processing waste residues. In order to solve the problem of the reuse of lithium mica, tantalum and niobium and other minerals in such waste residues, it is urgent to develop a low-cost, high-efficiency, pollution-free and highly adaptable mineral processing method to improve the comprehensive utilization level of such waste residues and solve the key technical bottleneck problems in the field of lithium-containing porcelain clay ore processing. Summary of the invention

[0005] The purpose of the present invention is to provide a beneficiation method for comprehensively recovering tantalum, niobium and lithium from magnetic separation waste slag of porcelain clay (containing lithium) ore with low cost, good separation effect, high separation index, good stability and strong adaptability, aiming to solve the problem of resource utilization of magnetic separation waste slag under the existing technology.

[0006] The present invention is achieved by a method for comprehensively recovering tantalum, niobium and lithium from lithium-containing porcelain clay ore dressing waste residue, comprising the following steps:

[0007] (1) grinding lithium-containing ore dressing waste slag;

[0008] (2) The ground waste residue is classified by a high-frequency vibrating screen to obtain lithium mica concentrate I and undersize products;

[0009] (3) The undersize product obtained in step (2) is pre-enriched by using a spiral chute for roughing to obtain tantalum-niobium coarse concentrate I, spiral chute middlings, and fine mud tailings I, respectively;

[0010] (4) The fine mud tailings I obtained in step (3) are scavenged by a spreading chute to obtain tantalum-niobium coarse concentrate II and fine mud tailings;

[0011] (5) combining the tantalum-niobium coarse concentrate I and the tantalum-niobium coarse concentrate II obtained in step (3) and step (4) for concentrating on a shaking table to obtain a tantalum-niobium concentrate and a shaking table gravity separation tailings;

[0012] (6) combining the spiral chute ore and the shaking table gravity separation tailings obtained in step (3) and step (5), and concentrating and dehydrating them to obtain a higher concentration slurry;

[0013] (7) roughing the slurry obtained in step (6) to obtain a rough lepidolite concentrate and flotation tailings I; wherein the roughing process conditions for the lepidolite are: first adding 300 to 800 g / t of dispersant YF2-1 for 3 to 5 min, then adding 200 to 600 g / t of collector YP-02 for 2 to 3 min;

[0014] (8) The flotation tailings I obtained in step (7) are scavenged twice to obtain flotation tailings and two scavenged tailings, and the two scavenged tailings are returned to the previous layer in sequence; wherein the process conditions for scavenging the flotation tailings I twice are as follows: scavenging I adds a dispersant YF2-1 of 150-400 g / t, the operation time is 3-5 min, and then adds a collector YP-02 of 100-250 g / t, the action time is 2-3 min, and scavenging II adds a collector YP-02 of 50-150 g / t, the action time is 2-3 min;

[0015] (9) The lithium mica rough concentrate obtained in step (8) is beneficiated twice to obtain lithium mica concentrate II and two beneficiated intermediates, and the two scanned intermediates are sequentially returned to the previous layer operation; wherein the process conditions for beneficiating the lithium mica rough concentrate twice are: adding 100-400 g / t of dispersant YF2-1 to beneficiation I, and the operation time is 3-5 min, and adding 50-250 g / t of dispersant YF2-1 to beneficiation II, and the operation time is 3-5 min;

[0016] Preferably, in step (1), the grinding fineness is -0.15 mm and the content accounts for 65-90%.

[0017] Preferably, in step (2), the ore pulp concentration of the high-frequency vibrating screen classification operation is 15-20%, and the classification particle size is 0.074-0.30 mm.

[0018] Preferably, in step (6), the concentration process conditions are as follows: the concentration of the concentrated slurry is 25-35%.

[0019] Preferably, the dispersant YF2-1 is obtained by mixing sodium hexametaphosphate, poly (sodium 4-styrene sulfonate) and carboxymethyl hydroxypropyl guar gum in a mass ratio of 3:3:4 and stirring the mixture evenly.

[0020] Preferably, the collector YP-02 is obtained by mixing cotton oil soap, dodecyldimethyl[3-(triethoxysilyl)propyl]ammonium chloride and isomeric C13 ether amine in a mass ratio of 3:5:2 and stirring the mixture evenly.

[0021] The present invention overcomes the shortcomings of the prior art and provides a method for comprehensively recovering tantalum, niobium and lithium from lithium-containing ore dressing waste slag. The specific steps are as follows: Figure 1 As shown, it has the following technical features:

[0022] (1) The present invention pre-grinds the lithium-containing ore dressing waste slag to improve the monomer dissociation effect of tantalum, niobium and lithium minerals. The difference in grindability between lithium mica and main gangue minerals such as feldspar and quartz is utilized to creatively adopt high-frequency vibrating screen to recover large-diameter lithium mica to obtain high-purity lithium mica concentrate I, thereby avoiding the problem that large-diameter lithium mica is difficult to adhere to foam and settle in the tank during flotation operation. At the same time, the regrinding cost of the waste slag is greatly reduced, and the problem of over-crushing of fine-grained tantalum and niobium in the grinding process and the problem that gangue minerals are easy to be muddied are solved, thereby creating good conditions for the re-selection recovery of tantalum and niobium minerals and the flotation separation of fine-grained lithium mica and gangue minerals; the problem of re-recovery of tantalum and niobium minerals with poor monomer dissociation in the waste slag is solved through grinding and re-selection operations, the recovery of fine-grained tantalum and niobium minerals is strengthened by using a spreading chute to sweep and select, and the fine mud is cleverly removed by using the water flow action of the re-selection operation, thereby creating a good slurry environment for the flotation separation of lithium mica.

[0023] (2) The present invention uses YF2-1 as a dispersant, and uses the sodium hexametaphosphate and poly (sodium 4-styrene sulfonate) components in the agent to adjust the mineral surface potential, thereby improving the slurry dispersion effect; the carboxymethyl hydroxypropyl guar gum component in the agent is used to selectively complex and adsorb ferromagnetic impurities and metal ions in the slurry, thereby solving the problem of reduced surface property differences between lithium mica and gangue minerals due to surface pollution. YP-02 is used as a collector, and the carboxyl group in the cotton oil soap in the agent and the silicon group in dodecyl dimethyl [3-(triethoxysilyl)propyl] ammonium chloride are used to specifically adsorb on the surface of lithium mica, and the hydrogen bonding between the amino group and the cotton oil soap is used to form multilayer adsorption, and the isomeric C13 ether amine component is used to improve the overall dispersibility of the collector in the slurry, and the synergistic effect of the anion and cationic collectors is exerted to achieve high-selective capture of lithium mica, thereby solving the problem of flotation separation of lithium mica and gangue in a metal-contaminated environment. The dispersants YF2-1 and YP-02 used in the present invention are developed through a large number of quantum chemical calculations, reagent adsorption tests and flotation tests. The reagent components and proportions thereof have not been disclosed and are not easily conceivable in the art.

[0024] (3) In view of the problems that large pieces of lithium mica in lithium-containing mineral processing waste are easy to settle in the flotation process, the dissociation degree of tantalum-niobium mineral monomers is poor and difficult to recover, and ferromagnetic impurities and dissolved metal ions contaminate the surface of lithium mica and gangue minerals, making flotation separation difficult, the present invention adopts the process flow of "coarse-grained lithium mica screening recovery-tantalum-niobium gravity recovery-fine mud lithium mica flotation recovery" and high-efficiency flotation reagents, which realize the efficient comprehensive recovery of tantalum, niobium and lithium, and improve the comprehensive utilization level of lithium-containing mineral processing waste. This creative idea, process flow structure and complete set of technology as a whole for the resource utilization and re-processing of lithium-containing solid waste have not been disclosed and are not easy to think of. It is a new mineral processing method with low cost, high efficiency, no pollution and strong adaptability.

[0025] Compared with the prior art, the advantages of the present invention are:

[0026] ① The present invention solves the problem that large-diameter lepidolite is easy to sink in the flotation process, and in order to achieve a suitable particle size for selection, the grinding product is severely muddied, and a large amount of fine lepidolite produced is lost again with the fine mud. Through graded recovery, the lepidolite recovery effect is improved and the energy consumption of mineral processing is reduced.

[0027] ② The present invention solves the problem of flotation separation of lepidolite and gangue in a metal-contaminated environment on the surface of minerals, and improves the separation efficiency of lepidolite.

[0028] ③ The present invention solves the problem that valuable minerals in lithium-containing ore dressing waste are difficult to recover, achieves waste reduction and resource utilization, and improves the comprehensive utilization rate of resources. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 The present invention is a flow chart of the steps of a method for comprehensively recovering tantalum, niobium and lithium from lithium-containing ore dressing waste slag. DETAILED DESCRIPTION

[0030] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0031] Example 1

[0032] The separated lithium-containing ore dressing waste residue contains 1.91% Li2O, 0.031% Ta2O5, 0.027% Nb2O5, and TFe content of 1.60%. The main mineral components in the waste residue are iron lithium mica, quartz, and feldspar, and are associated with tantalum-niobium iron ore. The main ferromagnetic impurities are magnetite, hematite, and pyrrhotite. The diameter of the lithium mica flakes is mostly 0.20-0.40 mm, and the monomer dissociation degree is 75.26%. The tantalum-niobium minerals are mostly 0-0.26 mm, and the monomer dissociation degree is only 53.71%. The method of the present invention is used to separate the lithium-containing ore dressing tailings, and the separation steps are:

[0033] (1) grinding the lithium-containing ore dressing waste slag; wherein the grinding fineness is -0.15 mm and the content accounts for 80%;

[0034] (2) The ground waste residue is classified by a high-frequency vibrating screen to obtain lithium mica concentrate I and undersize products; wherein the classification particle size is 0.15 mm;

[0035] (3) The undersize product obtained in step (2) is pre-enriched by using a spiral chute for roughing to obtain tantalum-niobium coarse concentrate I, spiral chute middlings, and fine mud tailings I, respectively;

[0036] (4) The fine mud tailings I obtained in step (3) are scavenged by a spreading chute to obtain tantalum-niobium coarse concentrate II and fine mud tailings;

[0037] (5) combining the tantalum-niobium coarse concentrate I and the tantalum-niobium coarse concentrate II obtained in step (3) and step (4) for concentrating on a shaking table to obtain a tantalum-niobium concentrate and a shaking table gravity separation tailings;

[0038] (6) The spiral chute ore and the shaking table gravity separation tailings obtained in step (3) and step (5) are combined and concentrated and dehydrated to obtain a higher concentration slurry; wherein the concentration process conditions are: the concentration of the slurry after concentration is 32%.

[0039] (7) subjecting the ore pulp obtained in step (6) to rough separation of lithium mica to obtain lithium mica rough concentrate and flotation tailings I; wherein the lithium mica rough separation process conditions are: first adding 500 g / t of dispersant YF2-1 for an action time of 5 min, then adding 400 g / t of collector YP-02 for an action time of 3 min;

[0040] (8) The flotation tailings I obtained in step (7) are scavenged twice to obtain flotation tailings and two scavenged tailings, and the two scavenged tailings are returned to the previous layer in sequence; wherein the process conditions for scavenging the flotation tailings I twice are as follows: 200 g / t of dispersant YF2-1 is added to scavenging I, the operation time is 3 min, and then 150 g / t of collector YP-02 is added, and the action time is 2 min; 80 g / t of collector YP-02 is added to scavenging II, and the action time is 2 min;

[0041] (9) The lithium mica rough concentrate obtained in step (7) is beneficiated twice to obtain lithium mica concentrate II and two beneficiated intermediates, and the two beneficiated intermediates are returned to the previous operation in sequence; wherein the process conditions for beneficiating the lithium mica rough concentrate twice are: adding 200 g / t of dispersant YF2-1 to beneficiation I and the operation time is 5 min, and adding 70 g / t of dispersant YF2-1 to beneficiation II and the operation time is 5 min;

[0042] In this embodiment, lithium mica concentrate I with a yield of 19.62%, a Li2O grade of 4.06%, and a Li2O recovery rate of 41.71% was obtained, a tantalum-niobium concentrate with a yield of 0.062%, a Ta2O5 grade of 18.35%, a Nb2O5 grade of 21.65%, a Ta2O5 recovery rate of 36.70%, and a Nb2O5 recovery rate of 49.71% was obtained, and a lithium concentrate II with a yield of 20.59%, a Li2O grade of 3.38%, and a Li2O recovery rate of 36.44%. The weighted grade of lithium concentrate I and lithium concentrate II is 3.71%, and the total recovery rate of Li2O is 78.15%.

[0043] Example 2

[0044] The separated lithium-containing ore dressing waste residue contains 1.08% Li2O, 0.020% Ta2O5, 0.028% Nb2O5, and TFe content of 2.27%. The main mineral components in the ore are lithium white mica, quartz, and feldspar, with associated tantalum-niobium iron ore. The main ferromagnetic impurities are magnetite, hematite, and limonite. LA-ICP-MS analysis shows that the theoretical grade of lithium white mica is 2.84%. The method of the present invention is used to separate the lithium-containing ore dressing tailings, and the separation steps are as follows:

[0045] (1) grinding the lithium-containing ore dressing waste slag; wherein the grinding fineness is -0.15 mm and the content accounts for 85%;

[0046] (2) The ground waste residue is classified by a high-frequency vibrating screen to obtain lithium mica concentrate I and undersize products; wherein the classification particle size is 0.12 mm;

[0047] (3) The undersize product obtained in step (2) is pre-enriched by using a spiral chute for roughing to obtain tantalum-niobium coarse concentrate I, spiral chute middlings, and fine mud tailings I, respectively;

[0048] (4) The fine mud tailings I obtained in step (3) are scavenged by a spreading chute to obtain tantalum-niobium coarse concentrate II and fine mud tailings;

[0049] (5) combining the tantalum-niobium coarse concentrate I and the tantalum-niobium coarse concentrate II obtained in step (3) and step (4) for concentrating on a shaking table to obtain a tantalum-niobium concentrate and a shaking table gravity separation tailings;

[0050] (6) The spiral chute ore and the shaking table gravity separation tailings obtained in step (3) and step (5) are combined and concentrated and dehydrated to obtain a higher concentration pulp; wherein the concentration process conditions are: the pulp concentration after concentration is 30%.

[0051] (7) roughing the slurry obtained in step (6) to obtain a rough lepidolite concentrate and flotation tailings I; wherein the roughing process conditions for the lepidolite are: first adding 600 g / t of dispersant YF2-1 for 5 min, then adding 250 g / t of collector YP-02 for 3 min;

[0052] (8) The flotation tailings I obtained in step (7) are scavenged twice to obtain flotation tailings and two scavenged tailings, and the two scavenged tailings are returned to the previous layer in sequence; wherein the process conditions for scavenging the flotation tailings I twice are as follows: scavenging I adds 250 g / t of dispersant YF2-1, the operation time is 5 min, and then adds 150 g / t of collector YP-02, the action time is 3 min, and scavenging II adds 100 g / t of collector YP-02, the action time is 3 min;

[0053] (9) The lithium mica rough concentrate obtained in step (7) is beneficiated twice to obtain lithium mica concentrate II and two beneficiated intermediates, and the two beneficiated intermediates are returned to the previous operation in sequence; wherein the process conditions for beneficiating the lithium mica rough concentrate twice are: adding 250 g / t of dispersant YF2-1 to beneficiation I and the operation time is 5 min, and adding 150 g / t of dispersant YF2-1 to beneficiation II and the operation time is 5 min;

[0054] This embodiment obtains lithium concentrate I with a yield of 18.36%, a Li2O grade of 2.35%, and a Li2O recovery rate of 39.95%, a tantalum-niobium concentrate with a yield of 0.057%, a Ta2O5 grade of 14.87%, a Nb2O5 grade of 23.02%, a Ta2O5 recovery rate of 42.36%, and a Nb2O5 recovery rate of 46.87%, and a lithium concentrate II with a yield of 18.73%, a Li2O grade of 2.16%, and a Li2O recovery rate of 37.46%. The weighted grade of lithium concentrate I and lithium concentrate II is 2.25%, and the total recovery rate of Li2O is 77.41%.

[0055] Example 3

[0056] The separated lithium-containing ore dressing waste slag contains 1.56% Li2O, 0.041% Ta2O5, 0.028% Nb2O5, and 1.56% TFe. The main mineral components in the ore are lithium muscovite, quartz, and feldspar, with associated tantalum-niobate ore. The main ferromagnetic impurities are magnetite, hematite, limonite, and a small amount of pyrrhotite. The method of the present invention is used to separate the lithium-containing ore dressing waste slag, and the separation steps are as follows:

[0057] (1) grinding the lithium-containing ore dressing waste slag; wherein the grinding fineness is -0.15 mm and the content accounts for 82%;

[0058] (2) The ground waste residue is classified by a high-frequency vibrating screen to obtain lithium mica concentrate I and undersize products; wherein the classification particle size is 0.15 mm;

[0059] (3) The undersize product obtained in step (2) is pre-enriched by using a spiral chute for roughing to obtain tantalum-niobium coarse concentrate I, spiral chute middlings, and fine mud tailings I, respectively;

[0060] (4) The fine mud tailings I obtained in step (3) are scavenged by a spreading chute to obtain tantalum-niobium coarse concentrate II and fine mud tailings;

[0061] (5) combining the tantalum-niobium coarse concentrate I and the tantalum-niobium coarse concentrate II obtained in step (3) and step (4) for concentrating on a shaking table to obtain a tantalum-niobium concentrate and a shaking table gravity separation tailings;

[0062] (6) The spiral chute ore and the shaking table gravity separation tailings obtained in step (3) and step (5) are combined and concentrated and dehydrated to obtain a higher concentration pulp; wherein the concentration process conditions are: the pulp concentration after concentration is 30%.

[0063] (7) roughing the slurry obtained in step (6) to obtain a rough lepidolite concentrate and flotation tailings I; wherein the roughing process conditions for the lepidolite are: first adding 400 g / t of dispersant YF2-1 for 5 min, then adding 350 g / t of collector YP-02 for 3 min;

[0064] (8) The flotation tailings I obtained in step (7) are scavenged twice to obtain flotation tailings and two scavenged tailings, and the two scavenged tailings are returned to the previous layer in sequence; wherein the process conditions for scavenging the flotation tailings I twice are as follows: scavenging I adds 150 g / t of dispersant YF2-1, the operation time is 5 min, and then adds 100 g / t of collector YP-02, the action time is 3 min, and scavenging II adds 70 g / t of collector YP-02, the action time is 3 min;

[0065] (9) The lithium mica rough concentrate obtained in step (7) is beneficiated twice to obtain lithium mica concentrate II and two beneficiated intermediates, and the two beneficiated intermediates are returned to the previous operation in sequence; wherein the process conditions for beneficiating the lithium mica rough concentrate twice are: adding 150 g / t of dispersant YF2-1 to beneficiation I and the operation time is 5 min, and adding 50 g / t of dispersant YF2-1 to beneficiation II and the operation time is 5 min;

[0066] This embodiment obtains lithium concentrate I with a yield of 16.96%, a Li2O grade of 3.43%, and a Li2O recovery rate of 37.29%, a tantalum-niobium concentrate with a yield of 0.071%, a Ta2O5 grade of 27.36%, a Nb2O5 grade of 15.13%, a Ta2O5 recovery rate of 47.39%, and a Nb2O5 recovery rate of 38.36%, and a lithium concentrate II with a yield of 17.28%, a Li2O grade of 3.28%, and a Li2O recovery rate of 36.33%. The weighted grade of lithium concentrate I and lithium concentrate II is 3.35%, and the total recovery rate of Li2O is 73.62%.

[0067] The present invention provides a method for comprehensively recovering tantalum, niobium and lithium from lithium-containing ore dressing waste residue, belonging to the field of ore dressing technology. The present invention recovers coarse-grained lithium mica by screening through a high-frequency vibrating screen, recovers tantalum and niobium minerals by "spiral chute roughing-spreading chute sweeping-shaking table selection", recovers fine-grained lithium mica by flotation method with YF2-1 as a dispersant and YP-02 as a collector, realizes the comprehensive utilization of lithium-containing ore dressing waste residue, and improves the level of comprehensive resource utilization. The present invention is a high-efficiency ore dressing method with low cost, good separation effect, high separation index, good stability and strong adaptability, suitable for promotion and application.

[0068] In the above embodiments, the contents not described in detail in this specification are known prior art to professionals in the field. The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for comprehensive recovery of tantalum, niobium and lithium from lithium-containing ore dressing waste slag, characterized in that: The following steps are involved: (1) Grinding the lithium-containing ore dressing waste slag; (2) The ground waste residue is classified by a high-frequency vibrating screen to obtain lithium mica concentrate I and undersize products; (3) The undersize product obtained in step (2) is pre-enriched by using a spiral chute for roughing to obtain tantalum-niobium coarse concentrate I, spiral chute middlings, and fine mud tailings I, respectively; (4) The fine mud tailings I obtained in step (3) are scavenged by using a spreading chute to obtain tantalum-niobium coarse concentrate II and fine mud tailings; (5) combining the tantalum-niobium coarse concentrate I obtained in step (3) and the tantalum-niobium coarse concentrate II obtained in step (4) for concentrating on a shaking table to obtain a tantalum-niobium concentrate and a shaking table gravity separation tailings; (6) combining the spiral chute ore obtained in step (3) and the shaking table gravity separation tailings obtained in step (5), and concentrating and dehydrating them to obtain a higher concentration slurry; (7) The slurry obtained in step (6) is subjected to rough separation of lithium mica to obtain a lithium mica rough concentrate and flotation tailings I; wherein the rough separation process conditions of the lithium mica are: firstly adding 300-800 g / t of dispersant YF2-1 for 3-5 min, and then adding 200-600 g / t of collector YP-02 for 2-3 min; (8) scavenging the flotation tailings I obtained in step (7) twice to obtain flotation tailings and two scavenged tailings, and the two scavenged tailings are returned to the previous operation in sequence; The process conditions for the two scavenging of flotation tailings I are as follows: adding dispersant YF2-1 150-400g / t in scavenging I, the operation time is 3-5min, and then adding collector YP-02 100-250g / t, the action time is 2-3min; adding collector YP-02 50-150g / t, the action time is 2-3min in scavenging II; (9) The lepidolite rough concentrate obtained in step (7) is beneficiated twice to obtain lepidolite concentrate II and two beneficiated intermediates, and the two beneficiated intermediates are returned to the previous operation in sequence; The process conditions for the two times of selection of lithium mica rough concentrate are as follows: adding dispersant YF2-1 100-400g / t in selection I and the operation time is 3-5min, adding dispersant YF2-1 50-250g / t in selection II and the operation time is 3-5min; The dispersant YF2-1 is obtained by mixing sodium hexametaphosphate, poly (sodium 4-styrene sulfonate) and carboxymethyl hydroxypropyl guar gum in a mass ratio of 3:3:4 and stirring the mixture evenly; The collector YP-02 is obtained by mixing cotton oil soap, dodecyldimethyl[3-(triethoxysilyl)propyl]ammonium chloride and isomeric C13 ether amine in a mass ratio of 3:5:2 and stirring the mixture evenly.

2. The method for comprehensive recovery of tantalum, niobium and lithium from lithium-containing ore dressing waste slag as claimed in claim 1, characterized in that: In step (1), the fineness of the ground lithium-containing ore dressing waste slag is -0.15 mm and the content accounts for 65-90%.

3. The method for comprehensive recovery of tantalum, niobium and lithium from lithium-containing ore dressing waste slag as claimed in claim 1, characterized in that: In step (2), the ore pulp concentration of the high-frequency vibrating screen classification operation is 15-20%, and the classification particle size is 0.074-0.30 mm.

4. The method for comprehensive recovery of tantalum, niobium and lithium from lithium-containing ore dressing waste slag as claimed in claim 1, characterized in that: In step (6), the concentration process conditions are as follows: the concentration of the concentrated slurry is 25-35%.

Images