A method for flotation of lithium-bearing mica-containing tantalum-niobium tailings based on anionic-nonionic complex collector and polymer selective depression

Abstract

The application provides a lithium mica-containing tantalum and niobium tailings flotation method based on anionic-nonionic composite collection and polymer selective inhibition, and relates to the field of mineral flotation. The method comprises the following steps: mixing lithium mica-containing tantalum and niobium tailings and a terpolymer inhibitor for the first time to obtain a slurry; performing desliming treatment on the slurry to obtain a deslimed flotation feed; mixing the deslimed flotation feed and the terpolymer inhibitor for the second time to obtain a selectively inhibited slurry; and mixing the selectively inhibited slurry and an anionic-nonionic composite collector for the third time to obtain a lithium mica concentrate. Through the construction of an interface regulation system of "pre-dispersion desliming-selective inhibition-composite collection", the fine mud cover and mechanical entrainment are reduced, and the grade and recovery rate of the lithium mica concentrate are improved.

Description

Technical Field

[0001] This application relates to the field of mineral flotation, and in particular to a flotation method for tantalum-niobium tailings containing lithium mica based on anionic-nonionic composite collection and polymer selective inhibition. Background Technology

[0002] Lithium, a strategic and critical mineral resource in my country, is an important raw material for new energy batteries, energy storage materials, and high-end lithium salt chemical industries. With the rapid development of new energy vehicles and energy storage industries, the demand for lithium resources continues to grow, and its efficient development and utilization has become an important foundation for ensuring national energy security and supporting the development of strategic emerging industries.

[0003] Lepidolite is an important hard-rock lithium resource mineral in my country, especially abundant in areas like Yichun, Jiangxi Province, and has become a crucial component of my country's lithium resource supply system. Currently, a large amount of lithium resources in these areas are found in tantalum-niobium ore beneficiation tailings. After recovery from tantalum-niobium ore, the lepidolite particle size in the tailings is further refined, and the mud content increases significantly. Fine-grained lepidolite has a large specific surface area and high surface activity, making it prone to mudification and mechanical entrainment. Therefore, achieving efficient recovery of fine-grained lepidolite from tantalum-niobium tailings has become a significant technical challenge in the comprehensive utilization of lithium resources.

[0004] Currently, lepidolite is mainly recovered through flotation. However, because lepidolite, along with quartz, feldspar, and other major gangue minerals, belongs to the same aluminosilicate mineral family and has similar surface structures and interfacial properties, flotation separation is challenging. Existing technologies typically employ fatty acid anionic collectors, amine cationic collectors, or a combination of anionic and cationic collectors to collect lepidolite, supplemented by depressants such as water glass, sodium hexametaphosphate, and carboxymethyl cellulose to achieve separation of lepidolite from gangue minerals.

[0005] However, existing flotation technologies still have the following shortcomings: (1) Traditional collectors have limited ability to collect fine-grained lepidolite and are easily affected by slime and gangue in complex slurry systems, leading to a decrease in flotation recovery; (2) Conventional depressants mainly achieve their inhibitory effect by increasing the hydrophilicity of gangue minerals or improving the dispersion state of the slurry, but their selective inhibitory ability on silicate gangue minerals such as quartz and feldspar is limited, making it difficult to effectively expand the floatability difference between lepidolite and gangue minerals; (3) Anionic collectors and cationic collectors usually play an independent role, and existing processes The collection and inhibition processes lack a synergistic interface regulation mechanism, resulting in low reagent utilization efficiency; (4) Fine-grained minerals are prone to agglomeration, entrainment, and non-selective adsorption. To ensure concentrate quality, a complex process of "roughing-multiple cleaning-multiple scavenging" is often required, leading to high reagent consumption, high production costs, and poor process stability; (5) Existing technologies focus on the individual optimization of collectors or inhibitors, lacking research on constructing an integrated interface regulation mechanism of "selective inhibition-synergistic collection" for the lepidolite-quartz-feldspar system, making it difficult to balance concentrate grade and recovery rate.

[0006] To address the aforementioned issues, some studies have attempted to improve flotation performance by enhancing the effects of reagents. For example, patent document CN201510788440.2 discloses "A Beneficiation Depressant for Lithium Mica Flotation Process," proposing a compound depressant approach. This involves modifying traditional water glass by adding sodium phosphate and carboxymethyl cellulose to enhance the inhibition of gangue minerals, thus improving mineral separation performance to some extent. However, this technology involves high reagent dosages (the actual depressant dosage in the example reaches 600-900 g / t), requires numerous auxiliary regulators, and uses expensive carboxymethyl cellulose, increasing the cost of flotation reagents. Furthermore, the introduction of phosphorus increases the difficulty of subsequent wastewater treatment.

[0007] Another technology improves flotation recovery by optimizing the collector system. For example, patent document CN202410084593.8 discloses "A selective flotation collector for lepidolite and its application method," proposing a compound collector approach that is "non-desliming and non-acidic," which improves upon the traditional amine + acid system. However, its sodium hexametaphosphate dosage is still relatively high (500~1000 g / t in roughing), and the collector is compounded from five special chemicals (3-[N,N-dimethyl,N-octadecyl]ammonium-2-hydroxypropanesulfonate, etheramine, lauryl alcohol polyoxyethylene ether, triethanolamine oleic acid soap, etc.), requiring the use of a high-shear emulsifier (≥7000 rpm, 15~20 min) to prepare a suspension, making the preparation conditions harsh. Patent document CN202111477002.6 discloses "A Lithium Mica Flotation Collector and Its Application", proposing a process scheme of "no desliming, no additional inhibitors, and no pH adjuster". However, the optimal ratio of the collector is strict, and the market supply of special sulfosuccinamides such as A-18 is limited, and the price is much higher than that of traditional coconut oil primary amine. At the same time, the flotation process is still long, making it difficult to simplify the process.

[0008] Overall, existing technologies mostly focus on optimizing combination inhibitors or single-type collectors. The reagents are complex and the preparation conditions are harsh. They lack synergistic control over the mineral dispersion behavior and interfacial adsorption characteristics during the flotation of lepidolite, resulting in high reagent consumption, complex processes, and high production costs, which seriously restricts the efficient development and utilization of fine-grained lepidolite resources.

[0009] Therefore, there is an urgent need to develop a new flotation method suitable for the efficient recovery of fine-grained lepidolite. This method would reduce the effects of fine mud covering and mechanical entrainment through desliming pretreatment, and enhance the floatability difference between lepidolite and gangue minerals such as quartz and feldspar by combining selective interface control technology. This would improve the separation efficiency of fine-grained lepidolite, reduce the amount of fine-grained cleaning operations and reagent consumption while ensuring concentrate grade and recovery rate, and achieve efficient and green development and utilization of lepidolite resources. Summary of the Invention

[0010] The purpose of this application is to provide a flotation method for tantalum-niobium tailings containing lithium mica based on anionic-nonionic composite collection and polymer selective inhibition, so as to solve the above-mentioned problems.

[0011] To achieve the above objectives, this application provides a flotation method for tantalum-niobium tailings containing lithium mica based on anionic-nonionic composite collection and polymer selective inhibition, comprising: Tantalum-niobium tailings containing lithium mica and ternary copolymer inhibitors are first mixed and pulped to obtain a slurry; the slurry is then deslimed to obtain a deslimed flotation feed. The deslimed flotation feed and the terpolymer inhibitor are mixed a second time to obtain a selectively inhibited slurry. The selectively inhibiting slurry and the anionic-nonionic composite collector are then mixed and roughed to obtain lepidolite concentrate.

[0012] Optionally, the mass percentage of -0.074 mm particles in the tantalum-niobium tailings containing lepidolite is 60%-80%.

[0013] Optionally, the slurry has a mass concentration of 20%-40%.

[0014] Optionally, the stirring rate of the pulping process is 1000-2000 r / min, and the pulping time is 2-6 min.

[0015] Optionally, the terpolymer inhibitor is obtained by copolymerizing acrylic acid, 2-acrylamide-2-methylpropanesulfonic acid, and hydroxypropyl acrylate, and its molecular chain has carboxyl, sulfonic acid, amide, and hydroxy ester side chains. Optionally, the flotation method for tantalum-niobium tailings containing lithium mica based on anionic-nonionic composite collection and polymer selective inhibition simultaneously satisfies the following conditions: (1) The amount of the terpolymer inhibitor used in the first mixing is greater than 0 g / t of raw ore and less than or equal to 5 g / t of raw ore; (2) The amount of the terpolymer inhibitor used in the second mixing is 10-100 g / t of raw ore.

[0016] Optionally, the flotation method for tantalum-niobium tailings containing lithium mica based on anionic-nonionic composite collection and polymer selective inhibition simultaneously satisfies the following conditions: (1) The desliming treatment is carried out by hydrocyclone grading method; the diameter of the hydrocyclone sand discharge port in the hydrocyclone grading method is 0.5mm-1.5mm; (2) The amount of desliming in the desliming process accounts for 5%-25% of the total mass of the lithium mica-containing tantalum-niobium tailings.

[0017] Optionally, the anionic-nonionic composite collector includes BK428; BK428 is prepared by reacting an aqueous solution of sodium alkyl diphenyl ether disulfonate (DOWFAX 2A1), dodecylamine and ethoxylated (tallow alkyl)amine in a mass ratio of 48.5:16.6:42, and its structure contains sulfonate anionic groups, sulfonamide linkage structures, long-chain alkyl hydrophobic groups and polyoxyethylene nonionic segments.

[0018] Optionally, the dosage of the anionic-nonionic composite collector is 100-500 g / t of raw ore.

[0019] Optionally, the flotation method for tantalum-niobium tailings containing lithium mica based on anionic-nonionic composite collection and polymer selective inhibition simultaneously satisfies the following conditions: (1) The coarse selection time is 2-8 minutes; (2) The pH of the roughing pulp is 7.0-10.5.

[0020] Compared with the prior art, the beneficial effects of this application include: This application provides a flotation method for lepidolite-containing tantalum-niobium tailings based on anionic-nonionic composite collectors and polymer selective inhibition. First, a small amount of ternary copolymer inhibitor with synergistic effects of multifunctional functional groups is added before desliming to improve the dispersion of fine mud, reduce fine mud covering and entrainment, and improve desliming and classification efficiency and fine mud removal effect. Second, after desliming, the ternary copolymer inhibitor is added again, utilizing carboxyl, sulfonic acid, amide, and hydroxy ester side chains to preferentially form a hydration adsorption layer on the surface of gangue minerals such as quartz and feldspar, reducing the non-selective adsorption of the collector by the gangue. Then, anionic-nonionic composite collectors are added to improve the adsorption, spreading, and hydrophobication of the reagent on the lepidolite surface. This constructs an interface control system of "pre-dispersion desliming—selective inhibition—composite collectors," enabling the acquisition of lepidolite concentrate through a single roughing process under natural pH or weakly alkaline conditions, reducing the number of cleaning cycles and lowering reagent consumption and operating costs. This application is particularly applicable to the recovery and utilization of fine-grained lithium mica resources in tantalum-niobium beneficiation tailings, and is of great significance for improving the comprehensive utilization rate of low-grade lithium resources, promoting the resource development of tailings, and realizing the efficient and clean utilization of lithium resources. Attached Figure Description

[0021] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly described below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation on the scope of this application.

[0022] Figure 1 A schematic diagram of the process for the flotation method of tantalum-niobium tailings containing lithium mica based on anionic-nonionic composite collection and polymer selective inhibition provided in this application; Figure 2 A schematic diagram of the conventional fine-grained lithium mica flotation process is provided for Comparative Example 6. Detailed Implementation

[0023] First, the solution provided in this application will be explained in more detail as follows: This application provides a flotation method for tantalum-niobium tailings containing lithium mica based on anionic-nonionic composite collecting and polymer selective inhibition, comprising: Tantalum-niobium tailings containing lithium mica and ternary copolymer inhibitors are first mixed and pulped to obtain a slurry; the slurry is then deslimed to obtain a deslimed flotation feed. It is important to note that the addition of a ternary copolymer inhibitor in the first mixing stage, at a dosage greater than 0 but not exceeding 5 g / t of raw ore, is primarily for pre-dispersing the fine mud to be removed. The carboxyl and sulfonic acid groups in the ternary copolymer, after ionization in water, can adsorb onto the surface of the fine mud particles, increasing the surface charge and hydration level. The steric hindrance generated by the polymer segments helps weaken the agglomeration between fine mud particles and between fine mud and lepidolite particles, causing some agglomerates to dissociate into particles with smaller apparent sizes and better dispersibility. In the centrifugal classification field of the hydrocyclone, the dispersed fine mud is more easily carried into the overflow discharge by the inner vortex, while coarser lepidolite particles mainly enter the settling sand by the outer vortex, thereby reducing fine mud covering, mechanical entrainment, and ineffective reagent consumption on the surface of the fine mud. This effectively solves the common problems of fine mud covering and mechanical entrainment in the flotation process of fine-grained lepidolite; in traditional processes, fine mud with a high specific surface area easily covers the surface of lepidolite and entrains gangue into the froth, leading to a decrease in concentrate grade. The deslimed flotation feed and the terpolymer inhibitor are mixed a second time to obtain a selectively inhibited slurry. It is important to note that during the second mixing after desliming, 10-100 g / t of terpolymer inhibitor from the raw ore is added, primarily for selective inhibition during the flotation stage. Carboxyl, amide, and hydroxy ester side chains can form a hydration adsorption layer on the surface of gangue minerals such as feldspar through hydrogen bonding, coordination, or bridging with metal ions in the pulp. Sulfonic acid groups help improve the negative charge and hydration stability of the mineral surface, reducing the probability of gangue particles adhering to bubbles, thereby inhibiting gangue flotation. Within the specified dosage range, the inhibitor has a relatively small impact on the floatability of lepidolite, which is beneficial for amplifying the floatability difference between lepidolite and gangue. This selective inhibition combined with desliming further amplifies the interfacial property differences between lepidolite and gangue minerals, overcoming the problems of insufficient selectivity and large dosage of existing single inhibitors (such as water glass, CMC, or phosphates). Good gangue inhibition can be achieved at a relatively low addition amount (preferably 20-60 g / t). The selectively inhibiting slurry and the anionic-nonionic composite collector are then mixed and roughed to obtain lepidolite concentrate.

[0024] In some embodiments, the coarse selection includes a first coarse selection.

[0025] It is important to note that the alkyl diphenyl ether backbone and long-chain alkyl groups in BK428 provide hydrophobic interactions, the sulfonate groups help maintain its dispersibility in the aqueous phase, the sulfonamide linkage structure and its adjacent polar groups may form hydrogen bonds, electrostatic interactions, or coordination interactions with the active sites on the lepidolite surface, and the polyoxyethylene segments are beneficial for improving the wetting, spreading, and interfacial alignment of the agent. Compared with the simple physical compounding of dodecylamine and sodium oleate, BK428 combines multiple functional structures in the same composite molecule, which can reduce the effective concentration loss caused by the association of compounded agents and improve the hydrophobicity efficiency of the fine-grained lepidolite surface; the adsorption response of BK428 to the quartz and feldspar surfaces covered by the terpolymer is weakened, thus forming a selective "inhibition-collection" synergy. It breaks through the limitations of poor selectivity and high reagent dosage when traditional anionic or cationic collectors are used alone. It can obtain excellent flotation indicators under conventional conditions with a collector dosage of 100-500 g / t, while avoiding the harsh preparation conditions such as complex reagent compounding and high shear emulsification in existing technologies. Thanks to the integrated technology of desliming pretreatment, ternary polymer inhibitor and anionic-nonionic composite collector, lithium mica concentrate with a Li2O grade of over 2% and a recovery rate of over 80% can be obtained in flotation with only one roughing stage. Compared with the complex process of "roughing-multiple cleaning-scavenging" commonly used in existing technologies, this application greatly simplifies the process, reduces operating variables, equipment investment and reagent consumption, and improves production stability and economy. It is especially suitable for the efficient recovery of fine-grained and easily mud-forming lithium mica resources in tantalum and niobium beneficiation tailings.

[0026] The flowchart of the flotation method for tantalum-niobium tailings containing lithium mica based on anionic-nonionic composite collection and polymer selective inhibition provided in this application is shown below. Figure 1 As shown.

[0027] Overall, this application addresses the industry challenges of high difficulty, complex process, and high reagent costs in the separation of fine-grained lepidolite resources. It constructs a complete technical route of "pre-desliming—multifunctional polymer inhibition—anionic-nonionic composite collection—primary roughing—primary scavenging." Compared with existing technologies, it not only significantly improves concentrate grade and recovery rate and reduces reagent consumption and wastewater treatment burden, but also substantially simplifies the flotation process, demonstrating good industrial application value and comprehensive resource utilization benefits.

[0028] In some embodiments, the mass percentage of -0.074 mm particles in the tantalum-niobium tailings containing lepidolite is 60%-80%.

[0029] Optionally, the mass percentage of -0.074 mm particles in tantalum-niobium tailings containing lepidolite can be any value between 60%, 62%, 64%, 66%, 68%, 70%, 72%, 74%, 76%, 78%, 80%, or 60-80%.

[0030] Preferably, the mass percentage of -0.074 mm particles in the tantalum-niobium tailings containing lepidolite is 65%-75%.

[0031] In some embodiments, the slurry has a mass concentration of 20%-40%.

[0032] Optionally, the mass concentration of the slurry can be any value between 20%, 22%, 24%, 26%, 28%, 30%, 32%, 34%, 36%, 38%, 40%, or 20-40%.

[0033] Preferably, the mass concentration of the slurry is 25%-35%.

[0034] In some embodiments, the stirring rate of the pulping process is 1000-2000 r / min, and the pulping time is 2-6 min.

[0035] Optionally, the stirring rate for pulping can be any value between 1000 r / min, 1100 r / min, 1200 r / min, 1300 r / min, 1400 r / min, 1500 r / min, 1600 r / min, 1700 r / min, 1800 r / min, 1900 r / min, 2000 r / min or 1000-2000 r / min, and the settling time can be any value between 2 min, 3 min, 4 min, 5 min, 6 min or 2-6 min.

[0036] In some embodiments, the terpolymer inhibitor is obtained by copolymerizing acrylic acid, 2-acrylamide-2-methylpropanesulfonic acid, and hydroxypropyl acrylate.

[0037] In some embodiments, the flotation method for tantalum-niobium tailings containing lithium mica based on anionic-nonionic composite collection and polymer selective inhibition satisfies at least one of the following conditions: (1) The amount of the terpolymer inhibitor used in the first mixing is greater than 0 g / t of raw ore and less than or equal to 5 g / t of raw ore; Optionally, the amount of the terpolymer inhibitor used in the first mixing can be 0.1 g / t raw ore, 0.5 g / t raw ore, 1 g / t raw ore, 2 g / t raw ore, 3 g / t raw ore, 4 g / t raw ore, 5 g / t raw ore, or any value greater than 0 g / t raw ore and less than or equal to 5 g / t raw ore; It is important to note that the amount of terpolymer inhibitor used in the first mixing stage cannot be zero. This is because without the addition of a pre-dispersant, fine mud with a high specific surface area is prone to agglomeration. Agglomerated fine mud exhibits a large apparent particle size, making it easy for it to be mistakenly included in the sediment and enter subsequent flotation, causing mud covering and mechanical entrainment. When the dosage exceeds 5 g / t of raw ore, the pulp viscosity may increase, the classification efficiency of the hydrocyclone may decrease, and the excess polymer may also adsorb onto the surface of lepidolite, causing some fine lepidolite particles to hydrate and be lost with the overflow. Therefore, controlling the dosage in the first mixing stage to be greater than zero and not exceeding 5 g / t of raw ore can balance the deagglomeration of fine mud and the recovery of lepidolite. The inhibitor required for the second mixing stage should not be added all at once during the first mixing stage: if all the reagent is added before desliming, some of the reagent will be ineffectively consumed by the overflow of fine mud, and the remaining excess reagent may also cause premature inhibition of lepidolite; adding it in two stages can achieve "pre-dispersion desliming" and "flotation selective inhibition" respectively. (2) The amount of the terpolymer inhibitor used in the second mixing is 10-100 g / t of raw ore.

[0038] Optionally, the amount of the terpolymer inhibitor used in the second mixing can be 10 g / t raw ore, 20 g / t raw ore, 30 g / t raw ore, 40 g / t raw ore, 50 g / t raw ore, 60 g / t raw ore, 70 g / t raw ore, 80 g / t raw ore, 90 g / t raw ore, 100 g / t raw ore, or any value between 10 and 100 g / t raw ore.

[0039] Preferably, the amount of the terpolymer inhibitor used in the second mixing is 20-60 g / t of raw ore.

[0040] It should be noted that when the dosage of the second mixture is less than 10 g / t of raw ore, the coverage of the inhibitor on the surface of quartz and feldspar may be insufficient, making it difficult to form a stable hydration adsorption layer. Gangue can still easily adsorb the collector and float with the foam. When the dosage is higher than 100 g / t of raw ore, excessive polymer may cause non-selective adsorption and increase the viscosity of the slurry, reducing bubble-particle collision and adhesion efficiency, while also increasing reagent costs. Therefore, controlling the dosage of the second mixture at 10-100 g / t of raw ore is beneficial to effectively suppress gangue while avoiding a significant decrease in the recovery rate of lepidolite, with 20-60 g / t of raw ore being the preferred range. In some embodiments, the flotation method for tantalum-niobium tailings containing lepidolite based on anionic-nonionic composite collection and polymer selective inhibition simultaneously meets the following conditions: (1) The desliming treatment is carried out by hydrocyclone grading method; the diameter of the hydrocyclone sand discharge port in the hydrocyclone grading method is 0.5mm-1.5mm; Optionally, the diameter of the hydrocyclone sedimentation port in the hydrocyclone classification method can be any value between 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1 mm, 1.1 mm, 1.2 mm, 1.3 mm, 1.4 mm, 1.5 mm or 0.5-1.5 mm; It is important to note that under pre-dispersion, the fine mud agglomerates in the slurry undergo deagglomeration and dispersion, reducing the mechanical covering effect of the fine mud particles on the lepidolite surface. During the hydrocyclone classification process, the finer particles mainly enter the overflow with the central inner cyclone, while the coarser particles form an outer cyclone along the vessel wall under centrifugal force and enter the sediment, thus achieving selective separation of fine mud from the target mineral particles.

[0041] In this application, the diameter of the hydrocyclone's underflow outlet is preferably controlled to be 0.5–1.5 mm. If the underflow outlet size is too small, the underflow discharge resistance increases, easily leading to blockages, rope-like discharge, and other abnormal phenomena, resulting in instability in the classification process and potentially causing fine-grained lepidolite to be lost with the overflow. If the underflow outlet size is too large, some fine mud particles may be discharged with the underflow, leading to a decrease in desliming efficiency and increasing the adverse effects of gangue minerals on subsequent flotation processes. Therefore, under the conditions of the pulp properties and feed particle size in this application, the specified underflow outlet size range can achieve a balance between stable discharge, effective desliming, and improved lepidolite recovery. (2) The amount of desliming in the desliming process accounts for 5%-25% of the total mass of the lithium mica-containing tantalum-niobium tailings.

[0042] Optionally, the amount of desliming treatment can be any value between 5%, 10%, 15%, 20%, 25% or 5-25% of the total mass of the tantalum-niobium tailings containing lepidolite.

[0043] It is important to note that when the desliming amount is controlled at 5%-25% of the total mass of the raw ore, some high specific surface area fine mud can be removed, reducing slurry viscosity, fine mud covering, mechanical entrainment, and non-selective consumption of the collector, thus creating a more stable slurry environment for subsequent selective inhibition and composite collection. When the desliming amount is less than 5%, the residual fine mud may still significantly interfere with flotation; when the desliming amount is more than 25%, some liberated or finely sized lepidolite may be lost with the overflow, leading to a decrease in lithium recovery. Without desliming treatment, fine mud easily covers the mineral surface, adsorbs a large amount of reagents, and enters the froth layer, causing a decrease in concentrate grade and recovery. In some embodiments, the anionic-nonionic composite collector includes BK428; BK428 is prepared by reacting an aqueous solution of sodium alkyl diphenyl ether disulfonate (DOWFAX 2A1), dodecylamine, and ethoxylated (tallow alkyl)amine in a mass ratio of 48.5:16.6:42.

[0044] In some embodiments, the dosage of the anionic-nonionic composite collector is 100-500 g / t of raw ore.

[0045] Optionally, the dosage of the anionic-nonionic composite collector can be 100 g / t raw ore, 150 g / t raw ore, 200 g / t raw ore, 250 g / t raw ore, 300 g / t raw ore, 350 g / t raw ore, 400 g / t raw ore, 450 g / t raw ore, 500 g / t raw ore, or any value between 100 and 500 g / t raw ore.

[0046] In some embodiments, the flotation method for tantalum-niobium tailings containing lithium mica based on anionic-nonionic composite collection and polymer selective inhibition satisfies at least one of the following conditions: (1) The coarse selection time is 2-8 minutes; Optionally, the coarse selection time can be any value between 2 min, 3 min, 4 min, 5 min, 6 min, 7 min, 8 min, or 2-8 min; Preferably, the coarse selection time is 3-5 minutes; (2) The pH of the roughing pulp is 7.0-10.5.

[0047] Optionally, the pH of the roughing pulp can be any value between 7, 7.5, 8, 8.5, 9, 9.5, 10, 10.5 or 7-10.5.

[0048] More preferably, the pH of the roughing pulp is 8.0-9.5.

[0049] Preferably, the pH of the roughing pulp can be any value between 8, 8.1, 8.2, 8.3, 8.4, 8.5, 8.6, 8.7, 8.8, 8.9, 9, 9.1, 9.2, 9.3, 9.4, 9.5, or 8-9.5.

[0050] The implementation schemes of this application will be described in detail below with reference to specific embodiments. However, those skilled in the art will understand that the following embodiments are only for illustrating this application and should not be regarded as limiting the scope of this application. Unless otherwise specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall apply. Reagents or instruments used without specified manufacturers are all conventional products that can be purchased commercially.

[0051] Example 1 This embodiment provides a flotation method for tantalum-niobium tailings containing lithium mica based on anionic-nonionic composite collection and polymer selective inhibition. Specifically: The tailings from a tantalum-niobium ore beneficiation mine in Yichun, Jiangxi Province, were used as the test sample. The raw ore had a Li₂O grade of 0.30%, and the main valuable mineral was lepidolite. The gangue minerals were mainly quartz and feldspar, with 68% of the particles being -0.074 mm. S1: Acrylic acid, 2-acrylamide-2-methylpropanesulfonic acid, and hydroxypropyl acrylate in a mass ratio of 4:2:1 are mixed and reacted at 70°C for 3 hours to obtain a terpolymer inhibitor; tailings and the terpolymer inhibitor are mixed to prepare a slurry with a mass concentration of 30%, wherein the amount of terpolymer inhibitor added is 5 g / t of raw material, and then deslimed by a Φ0.6 mm (diameter) hydrocyclone to remove fine mud below -20 μm, with a desliming amount of about 15%, to obtain a deslimed slurry; S2: Then add the terpolymer inhibitor prepared in S1 to the deslimed slurry at a dosage of 30 g / t of raw material, stir at a speed of 1705 r / min, adjust the slurry for 4 min, and then add the anionic-nonionic composite collector BK428 at a dosage of 300 g / t, and continue to adjust the slurry for 2 min. S3: The slurry is floated at a pH of 7.0-10.5. After one roughing process, the froth product is collected to obtain Li2O concentrate.

[0052] The grade of Li2O concentrate was 2.32%, and the recovery rate was 80.30%.

[0053] Example 2 This embodiment provides a flotation method for tantalum-niobium tailings containing lithium mica based on anionic-nonionic composite collection and polymer selective inhibition. Specifically: The tailings from a tantalum-niobium ore beneficiation mine in Yichun, Jiangxi Province, were used as the test sample. The raw ore had a Li₂O grade of 0.32%, and the main valuable mineral was lepidolite. The gangue minerals were mainly quartz and feldspar, with 70% of the particles being -0.074 mm. S1: The tailings and terpolymer inhibitor (the terpolymer inhibitor is the same as that in Example 1) are mixed to prepare a slurry with a mass concentration of 30%. The amount of terpolymer inhibitor added is 5g / t of raw material. Then, the slurry is deslimed by a Φ1.0mm hydrocyclone to remove fine mud below -20 μm. The desliming amount is about 10%, and the deslimed slurry is obtained. S2: Then add the terpolymer inhibitor prepared in S1 to the deslimed slurry at a dosage of 40 g / t of raw material, stir at a speed of 1705 r / min, adjust the slurry for 3 min, and then add the anionic-nonionic composite collector (same as in Example 1) at a dosage of 350 g / t, and continue to adjust the slurry for 2 min. S3: The slurry is flotated at a pH of 7-9. After one roughing process, the froth product is collected to obtain Li2O concentrate.

[0054] The grade of Li2O concentrate was 2.23%, and the recovery rate was 84.6%.

[0055] Example 3 This embodiment provides a flotation method for tantalum-niobium tailings containing lithium mica based on anionic-nonionic composite collection and polymer selective inhibition. Specifically: The tailings from a tantalum-niobium ore beneficiation mine in Yichun, Jiangxi Province, were used as the test sample. The raw ore had a Li₂O grade of 0.31%, and the main valuable mineral was lepidolite. The gangue minerals were mainly quartz and feldspar, with 70% of the particles being -0.074 mm. S1: The tailings and terpolymer inhibitor (the terpolymer inhibitor is the same as that in Example 1) are mixed to prepare a slurry with a mass concentration of 30%, wherein the amount of terpolymer inhibitor added is 5g / t of raw material. Then, the slurry is deslimed by a Φ1.5 mm hydrocyclone to remove fine mud below -20 μm, with a desliming amount of about 5%, to obtain the deslimed slurry. S2: Then add the terpolymer inhibitor prepared in S1 to the deslimed slurry at a dosage of 60 g / t of raw material, stir at a speed of 1705 r / min, adjust the slurry for 5 min, and then add an anionic-nonionic composite collector (same as in Example 1) at a dosage of 400 g / t, and continue to adjust the slurry for 3 min. S3: The slurry is flotated at a pH of 7-9. After one roughing process, the froth product is collected to obtain Li2O concentrate.

[0056] The grade of Li2O concentrate was 2.20%, and the recovery rate was 81.5%.

[0057] Comparative Example 1 The difference from Example 1 is that no terpolymer inhibitor was added in step S1 of Comparative Example 1.

[0058] Test results: The Li2O grade in Comparative Example 1 was 2.05%, and the recovery rate was 78.67%.

[0059] The results show that the combination of desliming pretreatment and terpolymer selective inhibition can effectively reduce the effects of fine mud covering and mechanical entrainment, and improve the flotation selectivity and recovery rate of fine-grained lepidolite.

[0060] Comparative Example 2 The difference from Example 1 is that Comparative Example 2 does not add a terpolymer inhibitor in step S2.

[0061] Test results: The Li2O grade in Comparative Example 2 was 1.77%, and the recovery rate was 81.2%.

[0062] The results showed that a high recovery rate could be obtained by using only anionic-nonionic composite collectors, but the inclusion of quartz and feldspar was severe, and the concentrate grade was significantly reduced.

[0063] Comparative Example 3 The difference from Example 2 is that in Comparative Example 3, the terpolymer inhibitor in steps 1 and 2 was replaced with an equal mass of water glass.

[0064] Test results: The Li2O grade in Comparative Example 3 was 2.07%, and the recovery rate was 73.49%.

[0065] The results showed that the terpolymer inhibitor had a better selective inhibitory effect on quartz and feldspar, and could significantly improve the concentrate grade while maintaining a high recovery rate.

[0066] Comparative Example 4 The difference from Example 3 is that in Comparative Example 4, the anionic-nonionic composite collector in steps 1 and 2 is replaced with an equal mass of dodecylamine and sodium oleate compound, wherein the mass ratio of dodecylamine to sodium oleate is 1:1.

[0067] Test results: The Li2O grade of Comparative Example 3 was 2.12%, and the recovery rate was 75.57%. The results show that the anionic-nonionic composite collector is a key component for improving the flotation grade of lepidolite and enhancing the selectivity of the reagent.

[0068] Comparative Example 5 The difference from Example 3 is that the desliming treatment in step S1 is not performed, and the slurry is directly subjected to flotation in steps S2 and S3.

[0069] Test results: Comparative Example 4 yielded a Li2O grade of 1.81% and a recovery rate of 71.24%.

[0070] The results showed that desliming, inhibitors, and collectors had a synergistic effect, which was beneficial to improving flotation indicators. Without desliming, the concentrate Li2O grade decreased from 2.20% to 1.81%, and the recovery rate decreased from 81.5% to 71.24%, a decrease of 0.39 percentage points and 10.26 percentage points, respectively. This was because the fine mud was not removed beforehand, leading to increased mud covering, non-selective adsorption of reagents, and enhanced mechanical entrainment by foam. This indicates that pre-dispersion desliming is a crucial step in achieving subsequent selective inhibition and efficient BK428 collection.

[0071] Comparative Example 6 The difference between Comparative Example 6 and Example 3 is that Comparative Example 6 uses conventional flotation processes and reagent regimens, as illustrated in the flowchart below. Figure 2 As shown.

[0072] The process flow of Comparative Example 6 is "pre-desliming - primary roughing - tertiary cleaning - primary scavenging". The primary filter modifier is Na2CO3, with a dosage of 300 g / t of raw ore; the depressant is sodium hexametaphosphate, with a dosage of 60 g / t of raw ore; the collector is a compound reagent of dodecylamine and sodium oleate (mass ratio of 1:1), with a dosage of 400 g / t of raw ore; the depressant for cleaning 1 is sodium hexametaphosphate, with a dosage of 30 g / t of raw ore; and the depressant for cleaning 2 is sodium hexametaphosphate, with a dosage of 10 g / t of raw ore.

[0073] Test results: Comparative Example 6 yielded a Li2O grade of 2.21% and a recovery rate of 74.46%, with a grade comparable to Example 3 but a lower recovery rate.

[0074] The results show that, compared with conventional flotation processes and reagents, the flotation method for tantalum-niobium tailings containing lithium mica based on anionic-nonionic composite collection and polymer selective inhibition provided in this application adopts the route of "pre-desliming - selective inhibition - synergistic collection - primary roughing - primary scavenging process". While reducing the number of fine scavenging processes, it can obtain better mineral processing indicators than conventional flotation processes with lower reagent types and dosages.

[0075] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

[0076] Furthermore, those skilled in the art will understand that although some embodiments herein include certain features included in other embodiments but not others, combinations of features from different embodiments are intended to be within the scope of this application and form different embodiments. For example, any of the claimed embodiments can be used in any combination. The information disclosed in this background section is intended only to enhance the understanding of the general background of this application and should not be construed as an admission or in any way implying that such information constitutes prior art known to those skilled in the art.

Claims

1. A flotation method for tantalum-niobium tailings containing lithium mica based on anionic-nonionic composite collection and polymer selective inhibition, characterized in that, include: Tantalum-niobium tailings containing lithium mica and ternary copolymer inhibitors are first mixed and pulped to obtain a slurry; The slurry is deslimed to obtain deslimed flotation feed; The deslimed flotation feed and the terpolymer inhibitor are mixed a second time to obtain a selectively inhibited slurry. The selectively inhibiting slurry and the anionic-nonionic composite collector are then mixed and roughed to obtain lepidolite concentrate.

2. The flotation method for tantalum-niobium tailings containing lithium mica based on anionic-nonionic composite collection and polymer selective inhibition according to claim 1, characterized in that, The mass percentage of -0.074 mm particles in the lithium mica-containing tantalum-niobium tailings is 60%-80%.

3. The flotation method for tantalum-niobium tailings containing lithium mica based on anionic-nonionic composite collection and polymer selective inhibition according to claim 1, characterized in that, The slurry has a mass concentration of 20%-40%.

4. The flotation method for tantalum-niobium tailings containing lithium mica based on anionic-nonionic composite collection and polymer selective inhibition according to claim 1, characterized in that, The stirring rate for pulp preparation is 1000-2000 r / min, and the pulp preparation time is 2-6 min.

5. The flotation method for tantalum-niobium tailings containing lithium mica based on anionic-nonionic composite collection and polymer selective inhibition according to claim 1, characterized in that, The terpolymer inhibitor is obtained by copolymerizing acrylic acid, 2-acrylamide-2-methylpropanesulfonic acid and hydroxypropyl acrylate.

6. The flotation method for tantalum-niobium tailings containing lithium mica based on anionic-nonionic composite collection and polymer selective inhibition according to claim 5, characterized in that, The following conditions must be met simultaneously: (1) The amount of the terpolymer inhibitor used in the first mixing is greater than 0 g / t of raw ore and less than or equal to 5 g / t of raw ore; (2) The amount of the terpolymer inhibitor used in the second mixing is 10-100 g / t of raw ore.

7. The flotation method for tantalum-niobium tailings containing lithium mica based on anionic-nonionic composite collection and polymer selective inhibition according to claim 1, characterized in that, The following conditions must be met simultaneously: (1) The desliming treatment is carried out by hydrocyclone grading method; the diameter of the hydrocyclone sand outlet in the hydrocyclone grading method is 0.5mm-1.5mm; (2) The amount of desliming in the desliming process accounts for 5%-25% of the total mass of the lithium mica-containing tantalum-niobium tailings.

8. The flotation method for tantalum-niobium tailings containing lithium mica based on anionic-nonionic composite collection and polymer selective inhibition according to claim 1, characterized in that, The anionic-nonionic composite collector includes BK428; BK428 is prepared by reacting 48.5 parts by mass of an aqueous solution of sodium alkyl diphenyl ether disulfonate, 16.6 parts by mass of dodecylamine and 42 parts by mass of ethoxylated (tallow alkyl)amine, and BK428 contains an alkyl diphenyl ether skeleton, sulfonate groups, sulfonamide linkage structure, long-chain alkyl groups and polyoxyethylene segments.

9. The flotation method for tantalum-niobium tailings containing lithium mica based on anionic-nonionic composite collection and polymer selective inhibition according to claim 8, characterized in that, The dosage of the anionic-nonionic composite collector is 100-500 g / t of raw ore.

10. The flotation method for tantalum-niobium tailings containing lithium mica based on anionic-nonionic composite collection and polymer selective inhibition according to any one of claims 1-9, characterized in that, The following conditions must be met simultaneously: (1) The coarse selection time is 2-8 minutes; (2) The pH of the roughing pulp is 7.0-10.5.

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