AU2022402780A1 - Method for comprehensively recovering lithium, tantalum-niobium, silicon-aluminum micro-powder, iron ore concentrate and gypsum from lithium slag - Google Patents

Abstract

A method for comprehensively recovering lithium, tantalum-niobium, silicon-aluminum micro-powder, iron ore concentrate and gypsum from lithium slag, relating to the technical field of lithium slag treatment. The method for comprehensively recovering lithium, tantalum-niobium, silicon-aluminum micro-powder, iron ore concentrate and gypsum from lithium slag comprises: performing gravity separation on lithium slag to obtain ore concentrate 1 and tailings 1, and performing weak magnetic separation on the ore concentrate 1 to obtain a coarse-grained tantalum-niobium rich material and coarse-grained iron ore concentrate; performing flotation on the tailings 1 to obtain gypsum and tailings 2; crushing the tailings 2; performing weak magnetic separation on the crushed tailings to obtain fine-grained iron ore concentrate and tailings 3; performing strong magnetic separation on the tailings 3 to obtain ore concentrate 2 and tailings 4, and drying the tailings 4 to obtain silicon-aluminum micro-powder; and performing gravity separation on the ore concentrate 2 to obtain fine-grained tantalum-niobium ore concentrate and a high-iron lithium-rich material. The problem that slag is difficult to treat in the lithium salt industry is solved. High-silicon high-aluminum low-iron low-sulfur silicon-aluminum micro-powder, and gypsum ore concentrate, iron ore concentrate, tantalum-niobium ore concentrate and high-iron lithium-rich slag having a purity of up to 95% can be obtained.

Description

Method for Comprehensively Recycling Lithium, Tantalum and Niobium, Silicon Aluminum Micropowder, Iron Concentrate, and Gypsum from Lithium Slags

CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the interests and priority of Chinese patent application CN2021114556395 filed on Dec. 1, 2021, which is hereby incorporated by reference in its entirety for all other purposes. Field of the Invention The invention relates to a method for comprehensively recycling lithium, tantalum and niobium, silicon aluminum micropowder, iron concentrate, and gypsum from lithium slags, and belongs to the technical field of treatment of lithium slags. Background of the Invention In today's world, comprehensive recycling of secondary resources of solid wastes is a major environmental protection theme, conducive to alleviating the shortage of national resources and moving towards the road of sustainable development, and the only way to create a conservation-oriented society. In recent years, supported by the policy to the comprehensive recycling of secondary resources, the comprehensive recycling of solid wastes has achieved remarkable results. With the development of economy and society, people's requirements for environmental and ecological protection have increased, and the shortage of resources has caused the problem of lagging economic development. The utilization of solid waste resources will have a huge development prospect. At present, the rapid development of the lithium battery industry has caused the demand growth for lithium resources. The extraction of lithium salt mainly depends on ores and salt lakes. The extraction of lithium from salt lakes is difficult to equalize the extraction of lithium from ores because of its high cost and impurity content. Spodumene is mainly used to extract lithium from ores, and many spodumene resources cannot be put into production on a large scale for various reasons. When spodumene is used to extract lithium, 7-8 tons of slags will be produced for every 1 ton of lithium salt, and more than 2 million tons of lithium slags will be annually produced based on the current yield of lithium salt. At present, lithium slags extracted from spodumene are mainly used as ingredients in cement, concrete and other low value-added fields, so that they cannot be quickly consumed. Stockpiling of lithium slags extracted from spodumene will undoubtedly bring about environmental pollution, land occupation and other problems, and their comprehensive utilization demand will become more urgent with the rapid development of the lithium battery industry. Patent CN1297860A and patent CN1090597C disclose ceramic glazed tiles made from acidic lithium slags and manufacturing methods thereof. The acidic lithium slags are used as their main ingredient. Wollastonite, pyrophyllite, and kaolin are used as their auxiliary materials. After grinding, pulping, compression filtration, mud caking, drying, crushing, compaction, drying, biscuiting, glaze firing and other steps, acidic lithium slags arefinally developed to manufacture ceramic glazed tiles in substitution of some traditional high-quality mineral materials. With the use of a small amount of lithium slags, the above patents have no technical advantage in quick consumption of a large amount of lithium slags. Patent CN103601230 discloses a method for producing a chemical material by comprehensively utilizing lithium slags. In the patent, calcium chloride, ammonium fluoride, white carbon black, aluminum salt, and ammonium sulfate are finally obtained through multiple steps. Thus, it cannot avoid the use of a large amount of acid solution, resulting in high acidity in exhaust gas and great production difficulty.

Patent CN108273826A discloses a full-phase high-valued recycling method of lithium slags, in which pyrophyllite raw material for glass fiber is obtained mainly through alkali conversion-magnetic separation. Gypsum and magnetic separation tailing are used as by-products. In the patent, an alkali conversion process is adopted and has the disadvantage of high cost and industrialization failure. Patent CN108147658A and patent W02019/141098A1 mainly describe that lithium pyrophyllite, gypsum, and magnetic separation tailing are prepared by a flotation-magnetic separation process. In the above two patents, although lithium slags have been high-valued to prepare pyrophyllite, calcium sulfate, tantalum and niobium, lithium, and other resources therein have not yet been high-valued. Patent CN214488258U discloses a system for comprehensively recycling lithium slags. For the system, a rough technology of pre-grinding and water recycling classification is mainly adopted to replace pulping operation, and flotation and alkali-to-solid-liquid two-phase desulfurization, iron removal through low-intensity magnetic separation and high-intensity magnetic separation, and recycling water subsection circulation are adopted to comprehensively utilize waste slags after lithium is extracted from lithium ores by a sulfuric acid process. The patent only provides a system and has the following disadvantages: pre-grinding will make such system more difficult to separate lithium slags from gypsum, resulting in the low yield of silicon aluminum micropowder produced by flotation and the high production cost. In addition, alkali conversion features in high cost, long time, and low efficiency, and it is difficult to scale up production. The system does not recycle iron and lithium from lithium slags, which undoubtedly causes wasting of resources without achieving comprehensive recycling. Chinese patent CN108191226A discloses a method for producing a glass fiber by using spodumene slags as a flux clarifying agent, and the proportion of the ingredients of the clarifying agent is as follows: 100-120 parts by mass of kaolin, 150-410 parts by mass of pyrophyllite, 150-200 parts by mass of quicklime, 50-70 parts by mass of dolomite, 50-70 parts by mass of colemanite, 130-310 parts by mass of quartzitic sandstone, 20-30 parts by mass of fluorite, and 10-30 parts by mass of spodumene slags. Chinese patent CN1114232223A discloses a method for preparing ceramics by using spodumene slags instead of kaolin. The ingredients of a ceramic blank respectively account for: 50-75% spodumene slags, 10-20% quartz sand, 1-10% potassium feldspar, and 1-10% albite. The ingredients of a ceramic glaze respectively account for: 40-60% spodumene slags, 15-40% quartz sand, 15-20% feldspar, and 1-10% chinastone. Chinese patent CN113480182A discloses a glass fiber with an industrial waste as a main ingredient and a preparation method thereof. The ingredients of the glass fiber include: 0-200 parts by mass of lithium industrial tailing, 70-200 parts by mass of coal gangue, and 400-650 parts by mass of silicon-aluminum associated ore. The invention proposes a glass fiber with an industrial waste as a main ingredient and a preparation method thereof. The industrial waste is rationally used to prepare pyrophyllite, kaolin, quartz, and other ingredients mainly used instead of an existing glass fiber, thereby reducing the industrial risk of the ingredients for preparing the glass fiber. CN1090597C discloses a method for manufacturing a ceramic glazed tile using acidic lithium slags. The method has the disadvantages of high cost, difficult industrialization, and slow consumption of lithium slags. Patent CN1112335C provides a technology for preparing a gypsum reinforcing agent using lithium slags extracted by a spodumene acid process. CN106082739A provides a technology for preparing a cement admixture by mixing lithium slags extracted by a spodumene acid process and drying the mixture. These patented technologies are still in the low-valued stage, and therefore the high-valued utilization of lithium slags extracted by spodumene is not better realized. To sum up, if a technology for comprehensively recycling lithium slags can be developed, gypsum, tantalum and niobium, iron, silicon aluminum micropowder and lithium in the lithium slags are fully recycled to successfully consume them, thereby ensuring the development of the lithium industry, and greatly promoting the sound and rapid development of the lithium industry and lithium slags treatment industry. All valuable components in the lithium slags are effectively utilized without solid waste, which will solve the worries about the lithium industry development in one stroke. Brief Summary of the Invention

The technical problem to be solved by the invention is to provide a method for comprehensively recycling lithium, tantalum and niobium, silicon aluminum micropowder, iron concentrate, and gypsum from lithium slags. In order to solve the first technical problem, the method for comprehensively recycling lithium, tantalum and niobium, silicon aluminum micropowder, iron concentrate, and gypsum from lithium slags includes the following steps: a. Performing gravity separation on the lithium slags to obtain concentrate 1 and tailing 1, and performing low-intensity magnetic separation on the concentrate 1 to obtain coarse tantalum and niobium concentrate and coarse iron concentrate; b. Performing flotation on the tailing 1 to obtain the gypsum and tailing 2; c. c. Crushing the tailing 2; d. Performing low-intensity magnetic separation on the crushed tailing in Step c to obtain fine iron concentrate and tailing 3; e. e. Performing high-intensity magnetic separation on the tailing 3 to obtain concentrate 2 and tailing 4, and drying the tailing 4 to obtain the silicon aluminum micropowder; f. Performing gravity separation on the concentrate 2 in Step e to obtain fine tantalum and niobium concentrate and high-iron lithium-enriched material, where the lithium slags are extracted from spodumene; the gravity separation in Step a is one of gravity separation by shaking table, spiral gravity separation, centrifugal gravity separation, gravity separation by hydrocyclone, gravity separation by jig, gravity separation by wind power, and gravity separation by dense medium, or a combination thereof; The flotation collector in Step b includes, by weight: 50-100 parts of at least one of C8-20 fatty acids and salts thereof; 1-30 parts of aviation kerosene; 1-30 parts of at least one of sulfonic acid containing dodecyl or sulfuric acid containing dodecyl and salt thereof; 1-30 parts of at least one of polyether or polyol; 1-10 parts of propylene oxide block copolymer; 1-10 parts of sorbitan monooleate; 1-10 parts of monoglyceride; 1-30 parts of behenyl trimethyl ammonium chloride; 1-10 parts of cetylpyridinium halide; 5-50 parts of alkali; 10-50 parts of silica sol; and 10-100 parts of water; the polyether or the polyol is at least one of polyvinylether, polyoxypropylene ether, polyvinyl alcohol, and polyoxyethylene ether, and preferably 1-10 parts of polyvinylether, 1-10 parts of polyoxypropylene ether, and 1-10 parts of polyvinyl alcohol; the propylene oxide block copolymer is at least one of PE6100, PE6200, PE6400, and PE8100; the sulfonic acid containing dodecyl or the sulfuric acid containing dodecyl includes dodecylbenzene sulfonic acid, dodecyl sulfonate, and sodiumdodecyl sulfate, preferably dodecylbenzene sulfonic acid and salt thereof; and more preferably 1-10 parts of dodecylbenzene sulfonic acid and salt thereof; the mass concentration of the silica sol is preferably 5%-40%; and the concentration of flotation ore pulp is 20%-60%. In a specific embodiment, the grades of tantalum and niobium in the lithium slags are calculated respectively based on Ta20s and Nb 2 0s and lower than 100 ppm, and preferably 50 ppm-100 ppm. Tantalum and niobium oxides in the lithium slags of the invention still can be recycled when their grades are less than 100 ppm, and their recycling rate is ensured to be greater than 45%. However, in the existing method, the low grades of tantalum and niobium result in their low recycling rate or abandonment of recycling; when the grades of tantalum and niobium are higher than 100 ppm, they can be better recycled by the method of the invention, with the higher recycling rate.

In a specific embodiment, the magnetic field intensity of the low-intensity magnetic separation is 100-2000 Gauss and preferably 300-1000 Gauss; the magnetic field intensity of the high-intensity magnetic separation is 10000-20000 Gauss and preferably 12000-17000 Gauss. In a specific embodiment, a modifier is added during the flotation in Step b, and at least one of a modifier is added during the flotation in Step b, and at least one of alumina sol, sodium pyrophosphate, polyepoxysuccinic acid or salt thereof, polyaspartic acid or salt thereof, carboxylate-sulfonate copolymer TH-2000, carboxylate-sulfonate-nonion tri-polymer TH-3100, phosphonocarboxylic acid copolymer POCA, polyacrylic acid or salt thereof, maleic acid-acrylic acid copolymer sodium salt, tannin, chitosan, and sodium carboxymethylcellulose, and preferably alumina sol, sodium pyrophosphate, polyacrylic acid or salt thereof, carboxylate-sulfonate copolymer TH-2000, and tannin; and the dosage of the modifier is preferably 0-6000 g/t lithium slags and more preferably 500-3000 g/t lithium slags. In a specific embodiment, the dosage of the collector in Step b is 50-3000 g/t lithium slags and preferably 100-1000 g/t lithium slags. In a specific embodiment, the flotation includes roughing, scavenging, and selection. Preferably, the roughing is performed by 1-3 times, the scavenging is performed by 1-4 times, and the selection is performed by 1-3 times. The dosage of the collector during the scavenging is 1/20-12/13 of that during the roughing, and no collector is added during the selection. Preferably, the dosage of the collector during first scavenging is 1/2 of that during the roughing, the dosage of the collector during second scavenging is 1/3 of that during the roughing, and the dosage of the collector during third scavenging is 1/4 of that during the roughing. In a specific embodiment, the crushed tailing 2 in Step c has the granularity of lower than 325 meshes. Preferably, the crushed tailing 2 is classified as particles having the granularity of more than 325 meshes and lower than 325 meshes, and the particles having the granularity of more than 325 meshes are mixed with the particles having the granularity of lower than 325 meshes after crushed. Preferably, a non-ferrous medium mill is used for grinding the crushed tailing. 325 meshes are approximate to 45um, lower than 325 meshes are approximate to lower than um, and more than 325 meshes are approximate to more than 45um. In a specific embodiment, concentration-filtration is further performed before drying in Step e. In a specific embodiment, the gravity separation in Step a includes roughing and selection. Preferably, the roughing is performed by 1-3 times, and the selection is performed by 1-3 times; and the gravity separation in Step f includes roughing and selection. Preferably, the roughing is performed by 1-3 times, and the selection is performed by 1-3 times. In a specific embodiment, C8-20 fatty acids and salts thereof in the collector include at least one of octanoic acid, nonanoic acid, decanoic acid, hendecanoic acid, lauric acid, tridecanoic acid, myristic acid, isocetic acid, palmitic acid, margaric acid, stearic acid, nonadecanoic acid, arachidic acid, oleic acid, linoleic acid, linolenic acid, and arachidonic acid; the aviation kerosene includes 1-10 parts of wide cut aviation kerosene. Preferably, the aviation kerosene further includes 1-10 parts of kerosene and 1-10 parts of heavy cut aviation kerosene; the monoglyceride includes at least one of glyceryl oleate, glyceryl stearate, glyceryl laurate, and glycerol palmitate, and preferably includes glyceryl laurate; the behenyl trimethyl ammonium chloride includes dodecyltrimethylammonium chloride to hexadecyl trimethyl ammonium chloride or dodecyltrimethylammonium bromide to hexadecyl trimethyl ammonium bromide, preferably dodecyltrimethylammonium chloride, tetradecyl trimethyl ammonium chloride, or hexadecyl trimethyl ammonium chloride; or dodecyltrimethylammonium bromide, tetradecyl trimethyl ammonium bromide, or hexadecyl trimethyl ammonium bromide; and more preferably dodecyltrimethylammonium chloride or dodecyltrimethylammonium bromide.

The alkali is at least one of sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, sodium bicarbonate, and potassium bicarbonate; and the salt is at least one of sodium salt, potassium salt, ammonium salt, calcium salt, and magnesium salt. The kerosene type of the aviation kerosene is also known as the intermediate cut of the aviation kerosene, and its boiling point is 150°C-280°C. The boiling point of heavy cut aviation kerosene is 190°C-315°C, and the boiling point of wide cut aviation kerosene is 60°C-280°C. In a specific embodiment, the flotation desulfurization collector for lithium tailings extracted from spodumene by a sulfuric acid process is prepared by the following method: a. Mixing the alkali with the silica sol according to their mass ratio, stirring the mixture for 0.5-24 h at 50°C-80°C, and making it react to obtain reagent A; and mixing other components excluding the alkali with the silica sol according to their mass ratio, stirring the mixture for 1-2 h at 80°C-100°C, and making it react to obtain reagent B; b. Mixing the reagent A with the reagent B to uniformity to obtain the flotation desulfurization collector for lithium tailings extracted from spodumene by a sulfuric acid process. The Invention has the following advantageous effects: 1. The invention thoroughly realizes the purpose of diversification and high-valued utilization of lithium slag deep-processed products, and solves a major ailing problem that slags are difficult to handle in the lithium salt industry. 2. In the invention, silicon aluminum micropowder with high silicon and aluminum and low iron and sulfur can be obtained, and used for the glass fiber, ceramics, paper making, and other industries to replace pyrophyllite, kaolin, talc, and other raw materials, thereby greatly reducing the production costs of glass fiber, ceramics and paper making industries. 3. In the invention, a high-quality gypsum concentrate is obtained through flotation and the gypsum has the purity up to 95% and belongs to a high-purity gypsum. Gypsum can be used not only as putty powder, but also for developing whisker gypsum materials, coatings, mold materials, and the like, thus improving the value of gypsum. 4. The invention takes full advantage of resource characteristics, and obtains iron concentrate through low-intensity magnetic separation, thereby further improving the value of comprehensive utilization of lithium slags. 5. In the invention, tantalum and niobium concentrate is obtained. If the content of the niobium and tantalum oxide is 150 ppm and the annual yield of lithium slags is 3 million tons, the total amount of the niobium and tantalum oxide is approximate to 450 tons. 6. In the invention, high-iron lithium-enriched slags are obtained. Lithium oxide (Li20)in the high-iron lithium-enriched slags is 1.0%-1.5%, and its yield is about 5%-10%. Based on the yield of 7%, the annual yield of the high-iron lithium-enriched slags is 210,000 tons, equivalent to about 2,000-3,000 tons of lithium metal. In addition, the high-iron lithium-enriched slags can be used as lithium ore to further recycle lithium carbonate. 7. There is a small numberof SO 3 in the remaining tailing after the flotation of the invention. If SO3 is less than 10% of lithium slags, SO 3 more than 0.1% of the tailing can be obtained through flotation. Brief Description of the Drawings FIG. 1 is a process flow chart according to an embodiment of the invention. FIG. 2 is a process flow chart of recycling a high-iron lithium-enriched material to extract lithium according to the invention.

FIG. 3 is a process flow chart of comprehensively recycling a high-iron lithium-enriched material by acid roasting. Detailed Description of Preferred Embodiments of the Invention In order to solve the first technical problem of the invention, the method for comprehensively recycling lithium, tantalum and niobium, silicon aluminum micropowder, iron concentrate, and gypsum from lithium slags includes the following steps: a. Performing gravity separation on the lithium slags to obtain concentrate 1 and tailing 1, and performing low-intensity magnetic separation on the concentrate 1 to obtain coarse tantalum and niobium concentrate and coarse iron concentrate; b. Performing flotation on the tailing 1 to obtain the gypsum and tailing 2; c. c. Crushing the tailing 2; d. Performing low-intensity magnetic separation on the crushed tailing in Step c to obtain fine iron concentrate and tailing 3; e. e. Performing high-intensity magnetic separation on the tailing 3 to obtain concentrate 2 and tailing 4, and drying the tailing 4 to obtain the silicon aluminum micropowder; f. Performing gravity separation on the concentrate 2 in Step e to obtain fine tantalum and niobium concentrate and high-iron lithium-enriched material, where the lithium slags are extracted from spodumene; the gravity separation in Step a is one of gravity separation by shaking table, spiral gravity separation, centrifugal gravity separation, gravity separation by hydrocyclone, gravity separation by jig, gravity separation by wind power, and gravity separation by dense medium, or a combination thereof; The flotation collector in Step b includes, by weight: 50-100 parts of at least one of C8-20 fatty acids and salts thereof; 1-30 parts of aviation kerosene; 1-30 parts of at least one of sulfonic acid containing dodecyl or sulfuric acid containing dodecyl and salt thereof; 1-30 parts of at least one of polyether or polyol; 1-10 parts of propylene oxide block copolymer; 1-10 parts of sorbitan monooleate; 1-10 parts of monoglyceride; 1-30 parts of behenyl trimethyl ammonium chloride; 1-10 parts of cetylpyridinium halide; 5-50 parts of alkali; 10-50 parts of silica sol; and 10-100 parts of water; the polyether or the polyol is at least one of polyvinylether, polyoxypropylene ether, polyvinyl alcohol, and polyoxyethylene ether, and preferably 1-10 parts of polyvinylether, 1-10 parts of polyoxypropylene ether, and 1-10 parts of polyvinyl alcohol; the propylene oxide block copolymer is at least one of PE6100, PE6200, PE6400, and PE8100; the sulfonic acid containing dodecyl or the sulfuric acid containing dodecyl includes dodecylbenzene sulfonic acid, dodecyl sulfonate, and sodiumdodecyl sulfate, preferably dodecylbenzene sulfonic acid and salt thereof; and more preferably 1-10 parts of dodecylbenzene sulfonic acid and salt thereof; the mass concentration of the silica sol is preferably 5%-40%; and the concentration of flotation ore pulp is 20%-60%. The components of the collector are allocated in any proportion within the corresponding range. If they are allocated in the corresponding proportion, the efficient flotation desulfurization of lithium slags can be realized, ensuring that the gypsum is more than 95%, the impurity SiO 2 in the gypsum is less than 1%, and the A12 0 3 is less than 1%, thus providing high-quality raw materials for the subsequent preparation of whisker gypsum. It should be pointed out that for the allocation of the collector according to the invention, its components can be effectively allocated to realize the rapid and efficient removal of sulfur from lithium slags. The high-quality gypsum can be easily obtained using the process of the invention. It is worth mentioning that the gypsum obtained through flotation according to the invention can be directly used as raw material, gypsum putty powder orfiller for producing gypsum whiskers after filtrated. The filtered water generated by flotation continues to reuse of flotation operation after being collected, and no wastewater discharge occurs in the invention. Considering that gypsum in the product takes away some water, water needs to be additionally provided in the production process of the invention to ensure normal production. In a specific embodiment, the grades of tantalum and niobium in the lithium slags are calculated respectively based on Ta20s and Nb 2 0s and lower than 100 ppm, and preferably 50 ppm-100 ppm. Tantalum and niobium oxides in the lithium slags of the invention still can be recycled when their grades are less than 100 ppm, and their recycling rate is ensured to be greater than 45%. However, in the existing method, the low grades of tantalum and niobium result in their low recycling rate or abandonment of recycling; when the grades of tantalum and niobium are higher than 100 ppm, they can be better recycled by the method of the invention, with the higher recycling rate. In a specific embodiment, the magnetic field intensity of the low-intensity magnetic separation is 100-2000 Gauss and preferably 300-1000 Gauss; the magnetic field intensity of the high-intensity magnetic separation is 10000-20000 Gauss and preferably 12000-17000 Gauss. In a specific embodiment, a modifier is added during the flotation in Step b, and at least one of a modifier is added during the flotation in Step b, and at least one of alumina sol, sodium pyrophosphate, polyepoxysuccinic acid or salt thereof, polyaspartic acid or salt thereof, carboxylate-sulfonate copolymer TH-2000, carboxylate-sulfonate-nonion tri-polymer TH-3100, phosphonocarboxylic acid copolymer POCA, polyacrylic acid or salt thereof, maleic acid-acrylic acid copolymer sodium salt, tannin, chitosan, and sodium carboxymethylcellulose, and preferably alumina sol, sodium pyrophosphate, polyacrylic acid or salt thereof, carboxylate-sulfonate copolymer TH-2000, and tannin; and the dosage of the modifier is preferably 0-6000 g/t lithium slags and more preferably 500-3000 g/t lithium slags. In a specific embodiment, the dosage of the collector in Step b is 50-3000 g/t lithium slags and preferably 100-1000 g/t lithium slags. In a specific embodiment, the flotation includes roughing, scavenging, and selection. Preferably, the roughing is performed by 1-3 times, the scavenging is performed by 1-4 times, and the selection is performed by 1-3 times. The dosage of the collector during the scavenging is 1/20-12/13 of that during the roughing, and no collector is added during the selection. Preferably, the dosage of the collector during first scavenging is 1/2 of that during the roughing, the dosage of the collector during second scavenging is 1/3 of that during the roughing, and the dosage of the collector during third scavenging is 1/4 of that during the roughing. In a specific embodiment, the crushed tailing 2 in Step c has the granularity of lower than 325 meshes. Preferably, the crushed tailing 2 is classified as particles having the granularity of more than 325 meshes and lower than 325 meshes, and the particles having the granularity of more than 325 meshes are mixed with the particles having the granularity of lower than 325 meshes after crushed. Preferably, a non-ferrous medium mill is used for grinding the crushed tailing. The classifying equipment may be a spiral classifier, a cyclone, a linear sieve, and the like. In a specific embodiment, concentration-filtration is further performed before drying in Step e. In a specific embodiment, the gravity separation in Step a includes roughing and selection. Preferably, the roughing is performed by 1-3 times, and the selection is performed by 1-3 times; and the gravity separation in Step f includes roughing and selection. Preferably, the roughing is performed by 1-3 times, and the selection is performed by 1-3 times.

In a specific embodiment, C8-20 fatty acids and salts thereof in the collector include at least one of octanoic acid, nonanoic acid, decanoic acid, hendecanoic acid, lauric acid, tridecanoic acid, myristic acid, isocetic acid, palmitic acid, margaric acid, stearic acid, nonadecanoic acid, arachidic acid, oleic acid, linoleic acid, linolenic acid, and arachidonic acid; the aviation kerosene includes 1-10 parts of wide cut aviation kerosene. Preferably, the aviation kerosene further includes 1-10 parts of kerosene and 1-10 parts of heavy cut aviation kerosene; the monoglyceride includes at least one of glyceryl oleate, glyceryl stearate, glyceryl laurate, and glycerol palmitate, and preferably includes glyceryl laurate; the behenyl trimethyl ammonium chloride includes dodecyltrimethylammonium chloride to hexadecyl trimethyl ammonium chloride or dodecyltrimethylammonium bromide to hexadecyl trimethyl ammonium bromide, preferably dodecyltrimethylammonium chloride, tetradecyl trimethyl ammonium chloride, or hexadecyl trimethyl ammonium chloride; or dodecyltrimethylammonium bromide, tetradecyl trimethyl ammonium bromide, or hexadecyl trimethyl ammonium bromide; and more preferably dodecyltrimethylammonium chloride or dodecyltrimethylammonium bromide. The alkali is at least one of sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, sodium bicarbonate, and potassium bicarbonate; and the salt is at least one of sodium salt, potassium salt, ammonium salt, calcium salt, and magnesium salt. The kerosene type of the aviation kerosene is also known as the intermediate cut of the aviation kerosene, and its boiling point is 150°C-280°C. The boiling point of heavy cut aviation kerosene is 190°C-315°C, and the boiling point of wide cut aviation kerosene is 60°C-280°C. In a specific embodiment, the flotation desulfurization collector for lithium tailings extracted from spodumene by a sulfuric acid process is prepared by the following method: a. Mixing the alkali with the silica sol according to their mass ratio, stirring the mixture for 0.5-24 h at 50°C-80°C, and making it react to obtain reagent A; and mixing other components excluding the alkali with the silica sol according to their mass ratio, stirring the mixture for 1-2 h at 80°C-100°C, and making it react to obtain reagent B; b. Mixing the reagent A with the reagent B to uniformity to obtain the flotation desulfurization collector for lithium tailings extracted from spodumene by a sulfuric acid process. In a specific embodiment, 50-100 parts of at least one of C8-20 fatty acids and salts thereof; 1-15 parts of aviation kerosene; 1-15 parts of at least one of sulfonic acid containing dodecyl or sulfuric acid containing dodecyl and salt thereof; 1-15 parts of at least one of polyether or polyol; 1-5 parts of propylene oxide block copolymer; 1-5 parts of sorbitan monooleate; 1-5 parts of monoglyceride; 1-20 parts of behenyl trimethyl ammonium chloride; 1-5 parts of cetylpyridinium halide; 10-50 parts of alkali; 10-50 parts of silica sol; and 10-50 parts of water; preferably, 1-5 parts of wide cut aviation kerosene, 1-5 parts of kerosene, and 1-5 parts of heavy cut aviation kerosene; preferably, 1-5 parts of dodecylbenzene sulfonic acid and salt thereof; 1-5 parts of sodiumdodecyl sulfate and salt thereof; and 1-5 parts of dodecyl sulfonate and salt thereof; preferably, 1-5 parts of polyvinylether, 1-5 parts of polyoxypropylene ether, and 1-5 parts of polyvinyl alcohol; and preferably, 1-5 parts of dodecyltrimethylammonium chloride or dodecyltrimethylammonium bromide; 1-10 parts of tetradecyl trimethyl ammonium chloride or tetradecyl trimethyl ammonium bromide, and 1-5 parts of hexadecyl trimethyl ammonium chloride or hexadecyl trimethyl ammonium bromide. In a specific embodiment, 50-100 parts of at least one of C8-20 fatty acids and salts thereof; 1-6 parts of aviation kerosene; 1-3 parts of at least one of sulfonic acid containing dodecyl or sulfuric acid containing dodecyl and salt thereof; 1-6 parts of at least one of polyether or polyol; 1-2 parts of propylene oxide block copolymer; 1 part of sorbitan monooleate; 1 part of monoglyceride; 1-3 parts of behenyl trimethyl ammonium chloride; 1 part of cetylpyridinium halide; 15-20 parts of alkali; 10 parts of silica sol; and 40-50 parts of water; preferably, 1-2 parts of wide cut aviation kerosene, 1-2 parts of kerosene, and 1-2 parts of heavy cut aviation kerosene; preferably, 1 part of dodecylbenzene sulfonic acid and salt thereof;1 part of sodiumdodecyl sulfate and salt thereof; and 1 part of dodecyl sulfonate and salt thereof; preferably, 1-2 parts of polyvinylether, 1-2 parts of polyoxypropylene ether, and 1-2 parts of polyvinyl alcohol; and preferably, 1 part of dodecyltrimethylammonium chloride or dodecyltrimethylammonium bromide; 1 part of tetradecyl trimethyl ammonium chloride or tetradecyl trimethyl ammonium bromide, and 1 part of hexadecyl trimethyl ammonium chloride or hexadecyl trimethyl ammonium bromide. In a specific embodiment, the method further includes the following steps: performing alkaline or acid roasting, leaching, and solid-liquid separation on the high-iron lithium-enriched material, and purifying and concentrating a filtrate subjected to the solid-liquid separation to obtain a lithium salt. As shown in FIG. 2, the high-iron lithium-enriched material may share a lithium extraction process with spodumene. Different from spodumene, the high-iron lithium-enriched material is directly subjected to alkaline or acid roasting rather than transformational roasting. For alkaline roasting or acid roasting, acid used in acid roasting is concentrated sulfuric acid. In principle, the concentrated sulfuric acid is more than 80% concentrated sulfuric acid, and preferably 98% concentrated sulfuric acid. As shown in FIG. 3, solid after solid-liquid separation is silicon aluminum micropowder and can be recycled. The following description will detail the specific embodiments of the present invention, and the invention will thereby not be limited to the embodiments. Example 1 As shown in FIG. 1, lithium slags extracted by spodumene from a company in Sichuan are used, and main minerals thereof include quartz, calcite, gypsum, gibbsite, andalusite, corundum, glassy phase, alpha-spodumene, beta-spodumene, zeolite, orthoclase, tantalite (trace), and niobite (trace). The grade of Ta20s is 90 ppm, the grade of Nb 2 0s is 50 ppm, and the grade of S03 is 6.2%. (I) Gravity separation-low-intensity magnetic separation A spiral chute is directly used for performing gravity separation on raw material; the concentrate obtained after gravity separation by spiral chute is subjected to gravity separation by shaking table, and the concentrate obtained after gravity separation by shaking table is subjected to low-intensity magnetic separation, where the magnetic field intensity is 1000 Gauss, and the magnetic separation tailing is a coarse tantalum and niobium concentrate, the grade of Ta20s is 18.56%, the grade of Nb 2 0s is 9.56%, and the recycling rates of tantalum and niobium are respectively 46.12% and 32.68%; and the magnetic separation concentrate is a coarse iron concentrate, where TFe is 52.13%, and the recycling rate thereof is 12.89%. (II) Floatation desulfurization Preparation of collector: firstly, 20 parts of sodium hydroxide and 50 parts of 40% silica sol are mixed, heated to 80°C and stirred for 5 hours to obtain paste A. . Secondly, 100 parts of C8-20 fatty acids/fatty acid salts (in the Example, they are a mixture of octanoic acid and lauric acid in a ratio of 1:1), 1 part of wide cut aviation kerosene, 1 part of intermediate cut aviation kerosene, 1 part of heavy cut aviation kerosene, 1 part of sodium dodecyl benzene sulfonate, 1 part of sodium dodecyl sulfate, 1 part of polyvinylether, 1 part of polyoxypropylene ether, 1 part of polyvinyl alcohol, 1 part of ethylene oxide-propylene oxide block copolymer EO-PO-EO (PE6100 used in this experiment), 1 part of sorbitan monooleate, 1 part of glyceryl monooleate (which is a mixture of glyceryl oleate, glyceryl stearate, glyceryl laurate, and glycerol palmitate glycerol palmitate in a ratio of 1:1), 1 part of dodecyl ammonium chloride, 1 part of hexadecyl trimethyl ammonium chloride, 1 part of cetyl pyridinium chloride monohydrate, and 50 parts of water are completely mixed well, heated to 80°C and stirred for 2h to obtain paste B. Finally, the paste A and the paste B are mixed to uniformity to obtain a lithium slag desulfurization collector C. Tailings obtained through gravity separation are directly subjected to flotation, and the concentration of flotation ore pulp is adjusted to 35%; taking ton as a unit of ore feeding, 2000g modifier and 300g collector are sequentially added for first roughing; the dosage of the second roughing modifier is 500g and the dosage of the collector is 100g; the roughing concentrate 1 and the roughing concentrate 2 are mixed to obtain a roughing concentrate, and the modifier during primary flotation is an alumina sol. The roughing concentrate is selected by one time and ores obtained through selection are returned to first roughing. The roughing tailing is performed for scavenging by three times; during first scavenging, the dosage of the modifier is 500g, and the dosage of the collector is 50g; during second scavenging, the dosage of the modifier is 250g, and the dosage of the collector is 30g; during third scavenging, the dosage of the modifier is 250g and the dosage of the collector is 20g; ores obtained through scavenging are returned to first roughing to form a closed-loop circulation to obtain a desulfurized gypsum concentrate and a desulfurized tailing, and the purity of CaSO 4.2H2 0 in the gypsum concentrate is more than 95%. (III) Classification-grinding-low-intensity magnetic separation Flotation tailings are classified as -325 mesh samples and +325 mesh samples. The +325 mesh samples are directly fed into a ceramic mill and ground to -325 mesh samples accounting for 100%. The tailings are classified as -325 mesh samples and mixed with them after ground, then directly subjected to low-intensity magnetic separation with the magnetic field intensity of 2000 Gauss, to obtain a fine iron concentrate with TFe of 42.23% and a yield of 8.2%. (IV) High-intensity magnetic separation- gravity separation An ore pulp obtained after low-intensity magnetic separation is directly fed into a high-intensity magnetic separator having the roughing magnetic field intensity of 1.2T and the scavenging magnetic field intensity of 1.7T, where roughing and scavenging are together used; the magnetic separation tailing and the magnetic tantalum and niobium enriched lithium product after high-intensity magnetic separation. The magnetic separation tailing is directly concentrated, filtered and dried to obtain silicon aluminum micropowder 1, with a yield of 75%; the grade of SO 3 is 0.15%, and the grade of Fe203 is 0.32%. The magnetic tantalum and niobium enriched lithium product is directly subjected to gravity separation by shaking table, a first gravity separation concentrate is directly selected, and ores obtained during first gravity separation are returned to gravity separation; a first gravity separation tailing is directly used as a tailing; thefirst gravity separation concentrate is subjected to second selection; a second gravity separation concrete is a final fine tantalum and niobium concentrate, and ores obtained during second gravity separation and tailings are directly returned to first gravity separation. After gravity separation, the fine tantalum and niobium concentrate and the high-iron lithium-enriched material are respectively obtained. In the fine tantalum and niobium concentrate, the grade of Ta20s is 10.52%, the grade of Nb 2 0s is 4.78%, and the recycling rates of tantalum and niobium are respectively 14.73% and 18.79%. In the high-iron lithium-enriched material, the grade of Li2 0 is 1.58% and the recycling rate of lithium is 25%. (V) Extraction of lithium from high-iron lithium-enriched material with sulfuric acid process

As shown in FIG. 2 and FIG. 3, 1000g high-iron lithium-enriched material and 5Og concentrated sulfuric acid with the concentration of 98% are mixed and placed in a muffle furnace, and roasted for 2h at a constant temperature of 300°C; the roasted material cooled is mixed with water according to a solid-liquid mass ratio of 1:1, the mixture is leached for 2h at 40°C; filtrate and silicon aluminum micropowder 2 are obtained after solid-liquid separation; 5ml hydrogen peroxide is added into the filtrate, with oxidation reaction for 0. 5h; calcium carbonate is added to adjust the pH value as 3, and a purified lithium solution and a calcium iron slag (cement retarder) are obtained through filtration. During extraction of lithium from a high-iron lithium-enriched material with a sulfuric acid process, the yield of silicon aluminum micropowder is 92%. A lithium carbonate product is obtained after concentration-sodium removal, lithium precipitation and other processes. In the entire process, the recycling rate of Li 2 0 is 20.5% (its recycling rate during operation is 82%). Example 2 Example 2 is similar to Example 1, except that 5 parts of wide cut aviation kerosene, 3 parts of intermediate cut aviation kerosene, and 3 parts of heavy cut aviation kerosene are provided. Example 3 Example 3 is similar to Example 1, except that no modifier is added. Examples 4-5 Examples 4-5 are similar to Example 1, except that the modifier in Example 4 is chitosan, and the modifier in Example 4 is sodium carboxymethylcellulose. Examples 6-7 Examples 6-7 are similar to Example 1, except that in Example 6, the magnetic field intensity of low-intensity magnetic separation is 1500 Gauss; in Example 7, the magnetic field intensity of high-intensity magnetic separation is 11000 Gauss. Examples 8-9 Examples 8-9 are similar to Example 1, except that in Example 8, the dosage of the first scavenging collector is 500g/t, the dosage of the second scavenging collector is 250g/t, and the dosage of the third scavenging collector is 100g/t; in Example 9, the dosage of the first scavenging modifier is 800g/t, the dosage of the second scavenging modifier is 500g/t, and the dosage of the third scavenging modifier is 200g/t. Table 1 Grades and Yields of Coarse Tantalum and Niobium Concentrates in Examples 1-9 Examples Grade of Ta205(%) Grade of Nb 2 05 (%) Yield of Ta205(%) Yield of Nb 2 05 (%)

1 18.56 9.56 46.12 32.68 2 19.88 10.51 47.22 33.69 3 18.06 9.16 45.35 31.68 4 20.51 9.92 46.17 33.68 5 19.51 10.51 46.12 33.98 6 19.51 9.26 45.42 31.68 7 18.51 9.99 45.45 32.66 8 17.56 10.51 44.19 32.64 9 18.59 9.88 46.17 30.69 Table 2 Grades and Yields of Fine Tantalum and Niobium Concentrates in Examples 1-9 Examples Grade of Ta205 (%) Grade of Nb 2 05 (%) Yield of Ta205 (%) Yield of Nb 2 05 (%) 1 10.52 4.78 14.73 18.79 2 11.5 4.99 13.41 17.99 3 11.12 4.98 14.71 18.78 4 11.12 5.18 13.93 16.79

5 10.12 4.18 14.03 16.09 6 9.98 4.98 14.79 18.77 7 10.11 4.95 14.78 17.79 8 12.52 4.08 15.93 17.47 9 10.59 4.98 14.73 18.99 Table 3 Grades and Yields of Iron Concentrates in Examples 1-9

Examples Grade of Fe in coarse Grade of Fe in fine Yield of Fe in coarse Yield of Fe in fine iron iron concentrate(%) iron concentrate (%) iron concentrate(%) concentrate(%) 1 52.13 42.23 12.89 8.2 2 55.23 41.61 12.12 8.64 3 53.44 42.67 13.19 8.34 4 52.25 42.27 10.89 9.88 5 51.15 42.87 13.81 8.25 6 50.88 45.28 14.81 7.82 7 52.33 42.71 13.79 8.91 8 53.11 43.22 12.12 9.3 9 52.93 43.28 12.91 8.24 Table 4 Grades and Yields of Silicon Aluminum Micropowder and Lithium Carbonate in Examples 1-9 Grade(0%) Examples Description Fe2O3 S0 3 Gi0 2 A1 2 0 3 Silicon aluminum 0.32 0.15 66.56 23.68 micropowder 1

S Silicon aluminum 0.45 0.18 64.33 22.06 micropowder 2 Grade ofLi 20 (%) Yield ofLi 2 0 (%) Lithium carbonate 40.35 20.5

2 Silicon aluminum 0.31 0.14 64.79 23.13 micropowder 1

3 Silicon aluminum 0.38 0.17 65.22 22.11 micropowder 1

4 Silicon aluminum 0.3 0.12 65.96 22.98 micropowder 1

5 Silicon aluminum 0.28 0.13 65.96 24.98 micropowder 1

6 Silicon aluminum 0.26 0.16 62.76 26.69 micropowder 1

7 Silicon aluminum 0.31 0.12 64.51 25.62 micropowder 1

8 Silicon aluminum 0.36 0.11 64.96 25.88 micropowder 1

9 Silicon aluminum 0.31 0.14 66.12 23.88 micropowder 1 Table 5 Grade and Yield of Gypsum in Examples 1-9 Yield (%) Grade (%) Examples SO 3 Si0 2 A1 2 0 3 CaSO 4 .2H 2 0 1 44.56 0.22 0.15 96.52 2 44.31 0.21 0.11 95.92 3 44.33 0.2 0.12 95.12 4 43.99 0.18 0.15 96.55 5 44.06 0.21 0.11 94.92

6 44.11 0.23 0.16 95.23 7 43.98 0.21 0.11 95.58 8 44.21 0.21 0.13 95.82 9 43.59 0.21 0.12 96.02

Claims (32)

1. Claims 1. A method for comprehensively recycling lithium, tantalum and niobium, silicon aluminum micropowder, iron concentrate, and gypsum from lithium slags, characterized by comprising the following steps: a. Performing gravity separation on the lithium slags to obtain concentrate 1 and tailing 1, and performing low-intensity magnetic separation on the concentrate 1 to obtain coarse tantalum and niobium concentrate and coarse iron concentrate; b. Performing flotation on the tailing 1 to obtain the gypsum and tailing 2; c. Crushing the tailing 2; d. Performing low-intensity magnetic separation on the crushed tailing in Step c to obtain fine iron concentrate and tailing 3; e. Performing high-intensity magnetic separation on the tailing 3 to obtain concentrate 2 and tailing 4, and drying the tailing 4 to obtain the silicon aluminum micropowder; f. Performing gravity separation on the concentrate 2 in Step e to obtain fine tantalum and niobium concentrate and high-iron lithium-enriched material, wherein the lithium slags are extracted from spodumene; the gravity separation in Step a is one of gravity separation by shaking table, spiral gravity separation, centrifugal gravity separation, gravity separation by hydrocyclone, gravity separation by jig, gravity separation by wind power, and gravity separation by dense medium, or a combination thereof; The flotation collector in Step b includes, by weight: 50-100 parts of at least one of C8-20 fatty acids and salts thereof; 1-30 parts of aviation kerosene; 1-30 parts of at least one of sulfonic acid containing dodecyl or sulfuric acid containing dodecyl and salt thereof; 1-30 parts of at least one of polyether or polyol; 1-10 parts of propylene oxide block copolymer; 1-10 parts of sorbitan monooleate; 1-10 parts of monoglyceride; 1-30 parts of behenyl trimethyl ammonium chloride; 1-10 parts of cetylpyridinium halide; 5-50 parts of alkali; 10-50 parts of silica sol; and 10-100 parts of water; the polyether or the polyol is at least one of polyvinylether, polyoxypropylene ether, polyvinyl alcohol, and polyoxyethylene ether; the propylene oxide block copolymer is at least one of PE6100, PE6200, PE6400, and PE8100; the sulfonic acid containing dodecyl or the sulfuric acid containing dodecyl comprises dodecylbenzene sulfonic acid, dodecyl sulfonate, and sodiumdodecyl sulfate.
2. 2. The method for comprehensively recycling lithium, tantalum and niobium, silicon aluminum micropowder, iron concentrate, and gypsum from lithium slags according to claim 1, characterized in that the polyether or the polyol is1-10 parts of the polyvinylether, 1-10 parts of polyoxypropylene ether, and 1-10 parts of polyvinyl alcohol.
3. 3. The method for comprehensively recycling lithium, tantalum and niobium, silicon aluminum micropowder, iron concentrate, and gypsum from lithium slags according to claim 1 or claim 2, characterized in that the sulfonic acid containing dodecyl or the sulfuric acid containing dodecyl comprises the dodecylbenzene sulfonic acid and salt thereof.
4. 4. The method for comprehensively recycling lithium, tantalum and niobium, silicon aluminum micropowder, iron concentrate, and gypsum from lithium slags according to claim 3, characterized in that the dodecylbenzene sulfonic acid and the salt thereof are 1-10 parts, respectively.
5. 5. The method for comprehensively recycling lithium, tantalum and niobium, silicon aluminum micropowder, iron concentrate, and gypsum from lithium slags according to claim 1 or 2, characterized in that the mass concentration of the silica sol is 5%- 4 0 %.
6. 6. The method for comprehensively recycling lithium, tantalum and niobium, silicon aluminum micropowder, iron concentrate, and gypsum from lithium slags according to claim 1 or 2, characterized in that the concentration of flotation ore pulp is 20%- 6 0 %.
7. 7. The method for comprehensively recycling lithium, tantalum and niobium, silicon aluminum micropowder, iron concentrate, and gypsum from lithium slags according to claim 1 or 2, characterized in that the grades of tantalum and niobium in the lithium slags are calculated respectively based on Ta20s and Nb 2 0 and lower than 100 ppm.
8. 8. The method for comprehensively recycling lithium, tantalum and niobium, silicon aluminum micropowder, iron concentrate, and gypsum from lithium slags according to claim 7, characterized in that the grades of tantalum and niobium in the lithium slags are calculated respectively based on Ta20s and Nb 2 0O and lower than 50 ppm-100 ppm.
9. 9. The method for comprehensively recycling lithium, tantalum and niobium, silicon aluminum micropowder, iron concentrate, and gypsum from lithium slags according to claim 1 or claim 2, characterized in that the magnetic field intensity of the low-intensity magnetic separation is 100-2000 Gauss; and the magnetic field intensity of the high-intensity magnetic separation is 10000-20000 Gauss.
10. 10. The method for comprehensively recycling lithium, tantalum and niobium, silicon aluminum micropowder, iron concentrate, and gypsum from lithium slags according to claim 9, characterized in that the magnetic field intensity of the low-intensity magnetic separation is 300-1000 Gauss.
11. 11. The method for comprehensively recycling lithium, tantalum and niobium, silicon aluminum micropowder, iron concentrate, and gypsum from lithium slags according to claim 9, characterized in that the magnetic field intensity of the high-intensity magnetic separation is 12000-17000 Gauss.
12. 12. The method for comprehensively recycling lithium, tantalum and niobium, silicon aluminum micropowder, iron concentrate, and gypsum from lithium slags according to claim 1 or claim 2, characterized in that a modifier is added during the flotation in Step b, and at least one of alumina sol, sodium pyrophosphate, polyepoxysuccinic acid or salt thereof, polyaspartic acid or salt thereof, carboxylate-sulfonate copolymer TH-2000, carboxylate-sulfonate-nonion tri-polymer TH-3100, phosphonocarboxylic acid copolymer POCA, polyacrylic acid or salt thereof, maleic acid-acrylic acid copolymer sodium salt, tannin, chitosan, and sodium carboxymethylcellulose.
13. 13. The method for comprehensively recycling lithium, tantalum and niobium, silicon aluminum micropowder, iron concentrate, and gypsum from lithium slags according to claim 12, characterized in that the modifier is alumina sol, sodium pyrophosphate, polyacrylic acid or salt thereof, carboxylate-sulfonate copolymer TH-2000, and tannin.
14. 14. The method for comprehensively recycling lithium, tantalum and niobium, silicon aluminum micropowder, iron concentrate, and gypsum from lithium slags according to claim 12, characterized in that the dosage of the modifier is 0-6000 g/t lithium slags.
15. 15. The method for comprehensively recycling lithium, tantalum and niobium, silicon aluminum micropowder, iron concentrate, and gypsum from lithium slags according to claim 14, characterized in that the dosage of the modifier is 500-3000 g/t lithium slags.
16. 16. The method for comprehensively recycling lithium, tantalum and niobium, silicon aluminum micropowder, iron concentrate, and gypsum from lithium slags according to claim 1 or claim 2, characterized in that the dosage of the collector in Step b is 50-3000 g/t lithium slags.
17. 17. The method for comprehensively recycling lithium, tantalum and niobium, silicon aluminum micropowder, iron concentrate, and gypsum from lithium slags according to claim 16, characterized in that the dosage of the collector in Step b is 100-1000 g/t lithium slags.
18. 18. The method for comprehensively recycling lithium, tantalum and niobium, silicon aluminum micropowder, iron concentrate, and gypsum from lithium slags according to claim 16, characterized in that the flotation comprises roughing, scavenging, and selection; the dosage of the collector during the scavenging is 1/20-13/12 of that during the roughing, and no collector is added during the selection.
19. 19. The method for comprehensively recycling lithium, tantalum and niobium, silicon aluminum micropowder, iron concentrate, and gypsum from lithium slags according to claim 18, characterized in that the roughing is performed by 1-3 times, the scavenging is performed by 1-4 times, and the selection is performed by 1-3 times.
20. 20. The method for comprehensively recycling lithium, tantalum and niobium, silicon aluminum micropowder, iron concentrate, and gypsum from lithium slags according to claim 19, characterized in that the dosage of the collector during first scavenging is 1/2 of that during the roughing, the dosage of the collector during second scavenging is 1/3 of that during the roughing, and the dosage of the collector during third scavenging is 1/4 of that during the roughing.
21. 21. The method for comprehensively recycling lithium, tantalum and niobium, silicon aluminum micropowder, iron concentrate, and gypsum from lithium slags according to claim 1 or claim 2, characterized in that the granularity of the crushed tailing 2 in Step c is more than 325 meshes.
22. 22. The method for comprehensively recycling lithium, tantalum and niobium, silicon aluminum micropowder, iron concentrate, and gypsum from lithium slags according to claim 21, characterized in that the crushed tailing 2 in Step c is classified as particles having the granularity of more than 325 meshes and lower than 325 meshes, and the particles having the granularity of more than 325 meshes are mixed with the particles having the granularity of lower than 325 meshes after crushed.
23. 23. The method for comprehensively recycling lithium, tantalum and niobium, silicon aluminum micropowder, iron concentrate, and gypsum from lithium slags according to claim 21, characterized in that a non-ferrous medium mill is used for grinding the crushed tailing.
24. 24. The method for comprehensively recycling lithium, tantalum and niobium, silicon aluminum micropowder, iron concentrate, and gypsum from lithium slags according to claim 1 or claim 2, characterized in that concentration-filtration is further performed before drying in Step e.
25. 25. The method for comprehensively recycling lithium, tantalum and niobium, silicon aluminum micropowder, iron concentrate, and gypsum from lithium slags according to claim 1 or claim 2, characterized in that the gravity separation in Step a comprises roughing and selection; and the gravity separation in Step f comprises roughing and selection.
26. 26. The method for comprehensively recycling lithium, tantalum and niobium, silicon aluminum micropowder, iron concentrate, and gypsum from lithium slags according to claim 25, characterized in that the gravity separation in Step a roughing by 1-3 times and selection by 1-3 times.
27. 27. The method for comprehensively recycling lithium, tantalum and niobium, silicon aluminum micropowder, iron concentrate, and gypsum from lithium slags according to claim 25, characterized in that the gravity separation in Step f comprises roughing by 1-3 times and selection by 1-3 times.
28. 28. The method for comprehensively recycling lithium, tantalum and niobium, silicon aluminum micropowder, iron concentrate, and gypsum from lithium slags according to claim 1 or claim 25, characterized in that C8-20 fatty acids and salts thereof in the collector comprise at least one of octanoic acid, nonanoic acid, decanoic acid, hendecanoic acid, lauric acid, tridecanoic acid, myristic acid, isocetic acid, palmitic acid, margaric acid, stearic acid, nonadecanoic acid, arachidic acid, oleic acid, linoleic acid, linolenic acid, and arachidonic acid; the aviation kerosene comprises 1-10 parts of wide cut aviation kerosene; the monoglyceride comprises at least one of glyceryl oleate, glyceryl stearate, glyceryl laurate, and glycerol palmitate; the behenyl trimethyl ammonium chloride comprises dodecyltrimethylammonium chloride to hexadecyl trimethyl ammonium chloride or dodecyltrimethylammonium bromide to hexadecyl trimethyl ammonium bromide; and the alkali is at least one of sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, sodium bicarbonate, and potassium bicarbonate; and the salt is at least one of sodium salt, potassium salt, ammonium salt, calcium salt, and magnesium salt.
29. 29. The method for comprehensively recycling lithium, tantalum and niobium, silicon aluminum micropowder, iron concentrate, and gypsum from lithium slags according to claim 28, characterized in that the aviation kerosene further comprises 1-10 parts of kerosene and 1-10 parts of heavy cut aviation kerosene.
30. 30. The method for comprehensively recycling lithium, tantalum and niobium, silicon aluminum micropowder, iron concentrate, and gypsum from lithium slags according to claim 28, characterized in that the monoglyceride comprises the glyceryl laurate.
31. 31.The method for comprehensively recycling lithium, tantalum and niobium, silicon aluminum micropowder, iron concentrate, and gypsum from lithium slags according to claim 28, characterized in that the behenyl trimethyl ammonium chloride is the dodecyltrimethylammonium chloride, tetradecyl trimethyl ammonium chloride, or the hexadecyl trimethyl ammonium chloride or the hexadecyl trimethyl ammonium bromide.
32. 32.The method for comprehensively recycling lithium, tantalum and niobium, silicon aluminum micropowder, iron concentrate, and gypsum from lithium slags according to claim 28, characterized in that the behenyl trimethyl ammonium chloride is the dodecyltrimethylammonium chloride or the dodecyltrimethylammonium bromide.