Fine-grained lepidolite high-efficiency collector, preparation method and application thereof

Abstract

The application discloses a fine-grained lepidolite high-efficiency collector and a preparation method and application thereof. The collector is composed of sodium oleate, oxidized paraffin soap, dodecylamine and ether amine. The combined collector has good selectivity and strong collecting capacity for fine-grained lepidolite recovery based on the synergistic effect among the components, and has good foamability. In the use process, a foaming agent does not need to be added separately, the dosage is smaller, but the mineral processing index is higher, and the problem of resource waste caused by the difficulty in fine mud recovery or low recovery rate in the traditional lepidolite recovery process is solved.

Description

Technical Field

[0001] This invention relates to a high-efficiency collector for fine-grained lepidolite and its preparation method, as well as a flotation recovery method for fine-grained lepidolite, belonging to the field of comprehensive recovery and beneficiation technology of fine-grained mineral resources. Background Technology

[0002] Lepidolite, as an important lithium mineral resource, has extremely high application value and strategic significance. It is a basic aluminosilicate of potassium and lithium, belonging to the mica group of minerals, and is commonly found in pegmatites, greisen, and high-temperature hydrothermal veins. The chemical composition of lepidolite is complex, mainly consisting of K and Li. 1.5 Al 1.5 [AlSi3O] 10 Lithium mica (F,OH)₂, with its monoclinic crystal structure and fine scaly aggregate characteristics, holds an important position in the fields of mineralogy and materials science. As lithium metal is an ideal raw material for lightweight alloy materials and new energy sources, the development and utilization of lepidolite is of significant strategic importance.

[0003] my country possesses abundant lithium resources, including large reserves of lepidolite, particularly in Jiangxi Province, which boasts the world's largest lepidolite mine. The development and utilization of these lithium resources are crucial for the growth of emerging industries such as new energy vehicles, energy storage, and electronic information. However, the extraction and utilization of lepidolite minerals face numerous technical challenges, especially the effective mining and utilization of low-grade ores with complex associated minerals, and the high cost and low efficiency of recovering lepidolite from lepidolite beneficiation slime.

[0004] Currently, the mining and purification of lepidolite suffers from significant resource waste, particularly during its flotation process. Over-grinding of the ore and the presence of primary slime lead to the generation of large quantities of fine slime, which contains abundant lepidolite. If this slime cannot be effectively recovered, it results in substantial resource waste. Traditional flotation technologies face challenges in processing fine-grained lepidolite, including high reagent consumption, low recovery efficiency, and unsatisfactory beneficiation indicators. In particular, the highly reactive chemical properties of lepidolite result in poor selectivity for collectors during flotation, making it difficult to meet the requirements of industrial production in terms of concentrate grade and recovery rate.

[0005] To address the aforementioned issues, researchers both domestically and internationally have recently attempted to improve the flotation efficiency and concentrate grade of lepidolite by utilizing different collector combinations. Studies have found that amine collectors exhibit good flotation effects on lepidolite, and mixed amines as collectors can significantly improve the recovery rate. Furthermore, by adjusting the collector combination and flotation process parameters, the flotation effect of lepidolite can be further optimized, reducing reagent consumption and improving economic efficiency. However, the separation efficiency and beneficiation indicators in the recovery of fine-grained lepidolite still need further improvement, especially in selectivity and collection capacity at low temperatures. Summary of the Invention

[0006] To address the shortcomings of existing methods for recovering fine-grained lepidolite, the first objective of this invention is to provide a highly efficient collector for fine-grained lepidolite. The components of this collector have an effective synergistic effect during the collection of lepidolite ore, mutually enhancing the collection effect on lepidolite minerals and thus improving hydrophobicity. The increased hydrophobicity makes it easier for lepidolite to adhere to air bubbles and be carried to the surface of the flotation cell, thereby achieving effective separation and recovery of lepidolite.

[0007] The second objective of this invention is to provide a method for preparing a high-efficiency collector of fine-grained lepidolite that is simple to operate, operates under mild conditions, and has low production costs.

[0008] The third objective of this invention is to provide an application of a high-efficiency collector for fine-grained lepidolite, which is used for the flotation recovery of fine-grained lepidolite. By using the high-efficiency collector for fine-grained lepidolite provided by this invention in combination with gangue dispersants and inhibitors, the problems of resource waste caused by the difficulty in recovering fine mud or low recovery rate in the traditional lepidolite recovery process are solved.

[0009] To achieve the above-mentioned technical objectives, the present invention provides a fine-grained lepidolite high-efficiency collector, comprising the following components by weight: 20-25 parts sodium oleate, 25-30 parts oxidized paraffin soap, 25-30 parts dodecylamine, and 20-25 parts etheramine.

[0010] Sodium oleate in this invention is a cationic collector. Sodium oleate reacts with cations on the mineral surface to form water-insoluble organic salts, making the mineral surface hydrophobic, which helps the mineral particles adhere to bubbles. Oxide paraffin soap is an anionic flotation agent. Under acidic or neutral conditions, it can react with metal ions to form hydrophobic metal soaps, thereby increasing the hydrophobicity of the mineral surface. The combined use of sodium oleate and oxide paraffin soap, both cationic and anionic collecting components, enables effective collection of lepidolite, especially fine-grained lepidolite. Dodecylamine is a cationic surfactant that adsorbs onto the mineral surface through ion exchange, improving the hydrophobicity of the mineral surface and increasing the flotation selectivity of lepidolite. Etheramine is also a cationic surfactant with a long hydrophobic chain and hydrophilic amine groups. It is commonly used to treat difficult-to-float and refined minerals, helping to improve the surface hydrophobicity of the minerals. This invention also rationally controls the mass fraction of the collector raw materials, allowing for effective synergistic effects among the above components, thereby achieving efficient flotation and separation and recovery of fine lepidolite ore.

[0011] As a preferred embodiment, the oxidized paraffin soap has a fatty acid content of not less than 50%, unsaponifiable matter of not more than 15%, free alkali of not more than 1%, and moisture content of not more than 30%. In this invention, the various indicators of the oxidized paraffin soap have a significant impact on the flotation effect, especially the fatty acid content; a higher content results in better flotation, while a lower content results in poorer flotation.

[0012] This invention also provides a method for preparing a high-efficiency collector for fine-grained lepidolite, which is obtained by mixing a solution containing sodium oleate, oxidized paraffin soap, dodecylamine, and etheramine. The preparation method provided by this invention is simple to operate, operates under mild conditions, and has low production costs, making it suitable for industrial application.

[0013] Finally, this invention also provides an application of a high-efficiency collector for fine-grained lepidolite, which is applied to the flotation recovery of fine-grained lepidolite. The specific process is as follows: after the lepidolite sludge is slurry-treated, a slurry is obtained; gangue mineral dispersant, inhibitor and collector are added to the slurry for aerated flotation to obtain lepidolite concentrate and lepidolite tailings.

[0014] As a preferred embodiment, the gangue mineral dispersant is sodium hexametaphosphate.

[0015] As a preferred embodiment, the inhibitor is SG-1, composed of water glass, oxalic acid, and sodium phosphate in a mass ratio of (50-60):10:(30-40). Water glass reacts with the surface of positively charged minerals in the pulp, such as silicates, to form a silica film, making the surface more hydrophilic and thus inhibiting flotation. Oxalic acid, through complexation with surface metal ions, alters the surface properties of the minerals, making them more hydrophilic. Sodium phosphate acts as a pH adjuster to change the acidity or alkalinity of the pulp. By controlling the combined dosage of these three components, the surface properties of lepidolite are regulated, thereby achieving selective inhibition of lepidolite and improving flotation efficiency.

[0016] As a preferred embodiment, the mass ratio of the gangue mineral dispersant, inhibitor, and collector is 1:(2.5-4):(1.6-4). Another innovation of this invention lies in the combined use of the composite collector with specific gangue mineral dispersants and inhibitors. The addition of sodium hexametaphosphate, the dispersant, increases the electrostatic repulsion between mineral particles, reducing the covering of fine mud on the lepidolite surface and creating conditions for the collector's adsorption on the mineral surface. The inhibitor SG-1, under the action of the dispersant, is directly adsorbed onto the gangue mineral surface, forming a hydrophilic film that inhibits gangue buoyancy. The combined effect of the dispersant sodium hexametaphosphate and the inhibitor SG-1, along with the addition of a collector, further facilitates the formation of a hydrophobic film on the target mineral surface, improving the floatability of the target mineral.

[0017] As a preferred embodiment, the pulp conditioning process controls the pulp concentration to 15-20% and the pH to 9-10. This invention controls the pulp concentration within the selected range and the flotation system within the alkaline range, which is more conducive to controlling the fluidity of the lepidolite pulp, thereby facilitating mineral flotation.

[0018] As a preferred embodiment, the aerated flotation is performed using a microbubble countercurrent contact flotation column, involving one roughing stage, at least two cleaning stages, and at least one scavenging stage. The reagent regimen for the roughing stage is as follows: the amount of gangue mineral dispersant relative to the lepidolite fine mud is 550–600 g / t, the amount of inhibitor relative to the lepidolite fine mud is 1500–2000 g / t, and the amount of collector relative to the lepidolite fine mud is 800–1500 g / t.

[0019] As a preferred embodiment, the selected reagent system is as follows: the amount of gangue mineral dispersant relative to lepidolite fine mud is 60-80 g / t, the amount of inhibitor relative to lepidolite fine mud is 100-200 g / t, and the amount of collector relative to lepidolite fine mud is 150-200 g / t.

[0020] As a preferred embodiment, the scavenging reagent system is as follows: the amount of gangue mineral dispersant relative to lepidolite fine mud is 120-160 g / t, the amount of inhibitor relative to lepidolite fine mud is 200-400 g / t, and the amount of collector relative to lepidolite fine mud is 300-400 g / t.

[0021] Another key to the superior flotation effect of the fine-grained lepidolite flotation recovery method of this invention lies in the use of a microbubble countercurrent contact flotation column. Since this invention targets fine-grained lepidolite, the flotation column utilizes a microbubble generator to inject gas into the column, producing a large number of microbubbles. The slurry is transported to the pre-bubble buffer tank of the flotation column via a slurry pump or a stepped gravity flow method. After being buffered sufficiently, the slurry enters the slurry distributor of the flotation column from the upper part through the feed pipe. This ensures uniform dispersion of the lepidolite slurry, facilitating thorough mixing and contact between the gas and the lepidolite slurry, thereby improving the recovery rate and concentrate grade during the flotation process.

[0022] As a preferred embodiment, the lithium mica tailings are subjected to reverse flotation to remove impurities and magnetic separation to remove iron, resulting in high-silicon aluminum ceramic material.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] 1) By selecting reasonable components and controlling their mass fraction, the collector obtained by this invention has good selectivity and strong collection ability for the recovery of fine-grained lepidolite. At the same time, it has good foaming properties, so there is no need to add foaming agent separately during use. Compared with other collectors, under the same conditions, the dosage is less, but the mineral processing index is higher.

[0025] 2) The fine-grained lepidolite high-efficiency collector provided by the present invention also has good stability and adaptability, and can adapt to flotation at temperatures below 5°C. It still has high selectivity and collection ability under low temperature conditions.

[0026] 3) The preparation method of the fine-grained lithium mica high-efficiency collector provided by the present invention is simple to operate, has mild conditions, and low production cost, making it suitable for industrialization.

[0027] 4) By using the fine-grained lithium mica high-efficiency collector and novel microbubble countercurrent contact flotation column provided by the present invention, many problems such as the difficulty in recovering fine mud or the low recovery rate caused by resource waste in the traditional lithium mica recovery process can be solved. Attached Figure Description

[0028] Figure 1 This is a flow chart of the flotation process in Example 1. Detailed Implementation

[0029] The present invention will be further described below with reference to specific embodiments, but the scope of protection of the present invention is not limited to the following specific embodiments. Obviously, the embodiments described below are only a part of the embodiments, and all other embodiments obtained by those skilled in the art without creative effort are still within the scope of protection of the present invention.

[0030] Unless otherwise specified, all raw materials, reagents, instruments and equipment used in this invention can be purchased from the market or prepared by existing methods.

[0031] The oxidized paraffin soap used in this invention has a fatty acid content of not less than 50%, unsaponifiable matter of not more than 15%, free alkali (NaOH) of not more than 1.0%, and moisture content of not more than 30%.

[0032] The dodecylamine used in this invention has a molecular weight of 185.35, a melting point of 28.3℃, a boiling point of 258.64℃, a flash point of 100.43℃, and a density of 0.805 g / cm³. 3 It is slightly soluble in water and has a purity of not less than 99%.

[0033] The industrial etheramine used in this invention has a purity of not less than 99% and an iodine value of less than 1.

[0034] Example 1

[0035] Heat water to 85°C, add sodium hydroxide to dissolve it completely, add oleic acid and sodium hydroxide in a mass ratio of 6.5:1 to the sodium hydroxide solution, stir quickly and thoroughly to saponify the oleic acid and obtain sodium oleate.

[0036] Dissolve the paste-like oxidized paraffin soap in water at 70°C, stirring constantly to ensure complete dissolution and obtain a 50% oxidized paraffin soap solution.

[0037] Take an acetic acid solution and dissolve dodecylamine in the acetic acid solution in a water bath at a mass ratio of 1:1. Add water to the above dodecylamine acetate solution according to the dodecylamine content to prepare a 50% dodecylamine acetate solution.

[0038] Take an acetic acid solution and dissolve the etheramine in the acetic acid solution in a water bath at a mass ratio of 1:1. Add water to the above etheramine acetate solution according to the content of etheramine to prepare a 50% etheramine acetate solution.

[0039] Sodium oleate solution (50% solute by mass), oxidized paraffin soap solution (50% solute by mass), dodecylamine solution (50% solute by mass), and etheramine solution (50% solute by mass) were mixed together at room temperature in a mass ratio of 2:3:3:2 and stirred thoroughly to obtain fine-grained lepidolite high-efficiency collector YX-2, which was then stored in drums for later use.

[0040] Fine-grained lepidolite is conveyed into the slurry mixing tank, where water is added for slurry preparation. The slurry concentration is adjusted to 15% through stirring. An automatic dosing system adds various prepared reagents to the mixing tank. First, a 10% sodium hydroxide solution is added to adjust the slurry pH to approximately 10, and stirring is performed for 5 minutes. Then, 5% sodium hexametaphosphate (600 g / t) and SG-1 inhibitor solution (composed of water glass, oxalic acid, and sodium phosphate in a mass ratio of 60:10:30) are added at a dosage of 1500 g / t to disperse the fine mud and inhibit gangue minerals, with stirring time of 5 minutes. Finally, 5% YX-2, a high-efficiency collector for fine-grained lepidolite, is added at a dosage of 1000 g / t, and stirring is performed. The time is 5 minutes. A new type of microbubble countercurrent contact flotation column is used. Through an automated control system, the process involves one roughing, two cleaning, and one scavenging process (the cleaning reagent system is as follows: gangue mineral dispersant is 60 g / t relative to lepidolite fine mud, inhibitor is 200 g / t relative to lepidolite fine mud, collector is 150 g / t relative to lepidolite fine mud, and the scavenging reagent system is twice the amount of the cleaning reagent system). With a lepidolite grade of about 0.3% in the fine mud lepidolite ore, a lepidolite concentrate grade of over 2.08% and a recovery rate of over 56.62% can be obtained.

[0041] Table 1 shows a comparison of the beneficiation indicators of YX-2, a high-efficiency collector for fine-grained lepidolite, and other lepidolite collectors.

[0042] Table 1. Comparison of flotation performance of YX-2 and other lepidolite collectors.

[0043]

[0044] As shown in Table 1, when the collector does not contain etheramine and dodecylamine, or does not contain sodium oleate and etheramine, the recovery rate and grade of lepidolite decrease significantly. The results indicate that the present invention achieves better flotation results through the synergistic effect of sodium oleate, oxidized paraffin soap, dodecylamine, and etheramine.

[0045] Example 2

[0046] The only difference between this embodiment and Example 1 is the amount of collector YX-2. The effect of different amounts of collector on the flotation index of lepidolite was investigated, and the results are shown in Table 2.

[0047] Table 2. Effects of different dosages of collector YX-2 on flotation parameters

[0048]

[0049] As shown in Table 2, the recovery rate increases with the increase of collector YX-2 dosage, but the grade of the concentrate first increases and then decreases. The flotation effect is best at a dosage of 1000 g / t. This is mainly because, under the dual action of dispersant sodium hexametaphosphate and depressant SG-1, more and more target minerals are collected as the collector dosage increases, and the recovery rate also increases. After a certain amount of collector is added, most of the target minerals that can float have already floated, and flotation is in an optimal state. However, if more collector is added at this point, impurities in the pulp will float to the surface, thus affecting the concentrate grade and causing it to decrease.

[0050] Comparative Example 1

[0051] The conditions and steps of this comparative example are the same as those of Example 1 when YX-2 is used as the collector. The only difference is that the microbubble countercurrent contact flotation column is replaced with a non-microbubble countercurrent contact flotation column. The comparison results of the flotation index are shown in Table 3.

[0052] Table 3 Comparison of performance indicators between microbubble countercurrent contact flotation columns and non-microbubble countercurrent contact flotation columns.

[0053]

[0054] As shown in Table 3, the flotation performance of the microbubble countercurrent contact flotation column is better than that of the non-microbubble countercurrent contact flotation column.

Claims

1. A flotation recovery method for fine-grained lepidolite, characterized in that: After the lepidolite mud is slurry treated, a slurry is obtained; gangue mineral dispersant, inhibitor and collector are added to the slurry and then subjected to aerated flotation to obtain lepidolite concentrate and lepidolite tailings. The collector is composed of the following components by mass: 20-25 parts sodium oleate, 25-30 parts oxidized paraffin soap, 25-30 parts dodecylamine, and 20-25 parts etheramine. The inhibitor is SG-1, which is composed of water glass, oxalic acid and sodium phosphate in a mass ratio of (50~60):10:(30~40); the mass ratio of gangue mineral dispersant, inhibitor and collector is 1:(2.5~4):(1.6~4).

2. The flotation recovery method for fine-grained lepidolite according to claim 1, characterized in that: The gangue mineral dispersant is sodium hexametaphosphate.

3. The flotation recovery method for fine-grained lepidolite according to claim 1, characterized in that: The oxidized paraffin soap has a fatty acid content of not less than 50%, unsaponifiable matter of not more than 15%, free alkali of not more than 1%, and moisture content of not more than 30%.

4. The flotation recovery method for fine-grained lepidolite according to claim 3, characterized in that: The pulp conditioning process controls the pulp concentration to be 15-20% and the pH to be 9-10.

5. The flotation recovery method for fine-grained lepidolite according to claim 4, characterized in that: The aerated flotation is obtained by using a microbubble countercurrent contact flotation column through one roughing, at least two cleaning and at least one scavenging process; The reagent system for roughing is as follows: the amount of gangue mineral dispersant relative to lepidolite fine mud is 550~600 g / t, the amount of inhibitor relative to lepidolite fine mud is 1500~2000 g / t, and the amount of collector relative to lepidolite fine mud is 800~1500 g / t. The selected reagent system is as follows: the amount of gangue mineral dispersant relative to lepidolite fine mud is 60~80g / t, the amount of inhibitor relative to lepidolite fine mud is 100~200g / t, and the amount of collector relative to lepidolite fine mud is 150~200g / t. The reagent system for scavenging is as follows: the amount of gangue mineral dispersant relative to lepidolite fine mud is 120~160 g / t, the amount of inhibitor relative to lepidolite fine mud is 200~400 g / t, and the amount of collector relative to lepidolite fine mud is 300~400 g / t.

6. A flotation recovery method for fine-grained lepidolite according to claim 4 or 5, characterized in that: The lithium mica tailings were subjected to reverse flotation to remove impurities and magnetic separation to remove iron, resulting in high-silicon aluminum ceramic material.

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