Application of a triazine hexapolyquaternary ammonium salt compound as a silicate mineral flotation collector
By using triazine hexameric quaternary ammonium salt compounds, the problems of high energy consumption and poor selectivity of traditional collectors have been solved, achieving efficient separation and low-energy flotation of lepidolite, and improving flotation efficiency and recovery rate.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- CENT SOUTH UNIV
- Filing Date
- 2026-06-09
- Publication Date
- 2026-07-24
AI Technical Summary
Traditional cationic collectors suffer from problems such as high energy consumption, poor selectivity, easy mud formation, and excessive foam stability in the flotation of lepidolite, making it difficult to efficiently separate and enrich lepidolite.
Triazine hexameric quaternary ammonium salt compounds are used as collectors. The synergistic effect of azinyl isolation groups, hydroxyl groups and quaternary ammonium salt groups is utilized to improve water solubility and dispersibility, and the adhesion is enhanced through multi-point anchoring, thereby reducing foam stability.
Achieving high selectivity and high recovery rate flotation at room temperature, reducing energy consumption, improving flotation efficiency, reducing reagent dosage, preventing fine-particle slime from covering, and improving foam performance.
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Figure CN122441561A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the application of a triazine hexameric quaternary ammonium salt compound as a flotation collector for silicate minerals, belonging to the field of mineral flotation. Background Technology
[0002] Lithium plays an irreplaceable role in new energy vehicles, energy storage, and portable electronic devices. Lepidolite is one of the important lithium-bearing minerals, with large reserves and wide distribution, and has become an important raw material for ensuring the security of the lithium resource supply chain. However, lepidolite ore is of low grade and often occurs in close association with aluminosilicate gangue minerals such as feldspar and quartz. Due to the high similarity of the crystal structure and surface physicochemical properties of these minerals, efficient separation and enrichment are extremely difficult.
[0003] In traditional lepidolite flotation processes, industrially used collectors are mostly mono-terminated fatty amines (such as dodecylamine and mixed amines). However, these conventional cationic collectors have revealed many insurmountable technical bottlenecks in practical applications: First, mono-terminated fatty amines have extremely poor water solubility at both room and low temperatures, and are prone to coagulation. Industrial production often requires a large amount of heat energy to heat the pulp or reagents, resulting in high overall beneficiation energy consumption and costs. Second, traditional monoamine collectors have poor selectivity and are prone to non-selective adsorption on the surface of gangue minerals such as feldspar and quartz, making it difficult to improve the grade of lithium concentrate. Finally, traditional amine reagents are highly sensitive to slime in the flotation system. Lepidolite itself is prone to sliming, and the covering of fine-grained slime often leads to a sharp increase in reagent consumption and even deterioration of the flotation process. At the same time, this process generates a large amount of viscous foam with mineral inclusions, which makes subsequent dewatering processes difficult.
[0004] Chinese patent application CN119680758A discloses a multi-component collector and its application in the flotation of low-grade lepidolite. The collector consists of cationic amine collectors, anionic promoters, and long-chain anionic collectors, significantly improving the collector's reactivity and its capture behavior of mineral particles during flotation. However, this method uses a wide variety of collectors, requires large quantities of flotation reagents, and cannot effectively solve the problem of fine-particle slime covering in lepidolite minerals.
[0005] To fundamentally solve the problems of extreme flotation conditions, excessive foam stability, and fine-particle slime capping associated with traditional cationic collectors, developing novel collectors with high selectivity, strong collecting power, excellent low-temperature resistance, and foaming properties at the molecular level has become a key technological breakthrough in this field. Summary of the Invention
[0006] To address the shortcomings of existing cationic collectors, such as extreme flotation conditions, excessive foam stability, and the covering effect of fine-particle slime, the present invention aims to provide a triazine hexameric quaternary ammonium salt compound as a flotation collector for silicate minerals. Through the synergistic multi-branched molecular structure of the azinyl isolation group, hydroxyl group, and quaternary ammonium salt group in the molecular structure, it exhibits excellent foaming and collecting performance for silicate minerals.
[0007] To achieve the above-mentioned technical objectives, the present invention provides an application of a triazine hexameric quaternary ammonium salt compound as a flotation collector for silicate minerals, wherein the triazine hexameric quaternary ammonium salt compound has the structural formula of Formula 1:
[0008]
[0009] Formula 1;
[0010] Where R is a quaternary ammonium salt group.
[0011] The key to the excellent foaming and collecting properties of the triazine hexameric quaternary ammonium salt compounds of this invention for silicate minerals lies in the synergistic effect between various functional groups and molecular structures. Specifically, the hydroxyl and quaternary ammonium salt groups on multiple branches in the molecular structure give the compound good water solubility and dispersibility in the pulp. Simultaneously, the conjugated groups composed of triazine rings and amines in the middle of the molecule coordinate with the active sites on the surface of silicate minerals. This multi-point anchoring effect increases the adhesion and intensity on the target mineral surface, thereby improving the collectability of the target mineral. Furthermore, the rigid triazine isolation structure in the molecular structure can be orderly arranged at the gas-liquid interface, significantly improving the liquid film fluidity of the bubbles, reducing foam stability, and improving foaming performance during flotation.
[0012] As a preferred embodiment, R has the structural formula of Equation 2:
[0013]
[0014] Formula 2;
[0015] in, The bonding sites are represented by X, which represents the equilibrium anion. R1 is an alkylene group, and R2 to R4 are the same or different alkyl or aryl groups.
[0016] As a preferred embodiment, X is a halogen, such as F, Cl, Br, etc.
[0017] As a preferred embodiment, R1 is methylene, R2 and R4 are selected from the same C1-C3 straight-chain alkyl group, and R3 is selected from C1-C4. 18Straight-chain alkyl groups or C6-C7 aromatic alkyl groups, such as benzyl, n-hexyl, n-octyl, n-decyl, n-dodecyl, n-tetradecyl, n-hexadecyl, or n-octadecyl.
[0018] Further preferably, R3 is benzyl, n-octane, or n-decyl. When a more preferred group is used, a compound with better overall performance can be obtained.
[0019] Taking X as chlorine and R1 as methylene as an example, as a preferred embodiment, the preparation process of the triazine hexameric quaternary ammonium salt compound is as follows: melamine and triethylamine are dissolved in N,N-dimethylformamide, epichlorohydrin is added, and a ring-opening alkylation reaction is carried out to obtain the intermediate of formula 3; then the intermediate of formula 3 is subjected to a quaternization reaction with the compound of formula 4 to obtain the product.
[0020]
[0021] Formula 3;
[0022]
[0023] Equation 4;
[0024] Wherein, R2 and R4 are selected from the same C1~C3 straight-chain alkyl group, and R3 is selected from C1~C3. 18 Straight-chain alkyl groups or C6-C7 aromatic alkyl groups, such as benzyl, n-hexyl, n-octyl, n-decyl, n-dodecyl, n-tetradecyl, n-hexadecyl, or n-octadecyl.
[0025] As a preferred embodiment, the ring-opening alkylation reaction is carried out at a temperature of 100-110°C for a time of 40-48 hours.
[0026] As a preferred embodiment, the quaternization reaction is carried out at a temperature of 75-85°C for a time of 16-20 hours.
[0027] As a preferred embodiment, the application process includes the following steps:
[0028] S1 involves grinding and slurry preparation of silicate mineral ore to obtain a slurry;
[0029] S2 adds flotation reagents, including triazine hexameric quaternary ammonium salt compounds, to the slurry for flotation and collects the flotation concentrate.
[0030] The above flotation steps can achieve excellent flotation results with a relatively small amount of collector.
[0031] As a preferred embodiment, the silicate minerals include at least one selected from lepidolite, quartz, potassium feldspar, sodium feldspar, and spodumene. Lepidolite is further preferred. When lepidolite is used, due to its relatively soft texture, it easily generates a large amount of fine slime during crushing and grinding, and traditional reagents are readily consumed in large quantities by the non-selective slime. However, the triazine hexameric quaternary ammonium salt compound of this invention has a large molecular volume and a rigid triazine ring framework. Its unique spatial configuration forms a denser hydrophobic layer after adsorption on the mineral surface. Simultaneously, its strong steric hindrance effectively prevents fine slime from covering the lepidolite surface, significantly improving the flotation system's tolerance to slime and maintaining excellent flotation performance even with a high slime content in the raw ore.
[0032] As a preferred embodiment, the grinding process controls the mineral content to be 55-85 wt% for a fineness of -200 mesh.
[0033] As a preferred embodiment, the slurry concentration is controlled at 25-45 wt%, and the pH is 5-10. A pH adjuster can be added during this process.
[0034] As a preferred embodiment, the grinding process further includes a desliming process. Preferably, the desliming process involves standing for 2-3 times, with each session lasting 3-5 minutes. When the selected silicate minerals include lepidolite, which contains a relatively high amount of fine mud, the desliming process can be increased to remove some of the mud.
[0035] As a preferred embodiment, the flotation includes at least one roughing stage, wherein the amount of triazine hexameric quaternary ammonium salt compound used in the roughing stage is 10-1500 g / t relative to the ore. More preferably, the amount of triazine hexameric quaternary ammonium salt compound used is 200-600 g / t relative to the ore. Even more preferably, the amount of triazine hexameric quaternary ammonium salt compound used is 200-300 g / t relative to the ore.
[0036] In order to further improve the flotation effect, inhibitors, frothers, etc. can be added to the flotation reagents according to different minerals and requirements.
[0037] Compared with the prior art, the present invention has the following beneficial effects:
[0038] (1) The triazine hexameric quaternary ammonium salt compound provided by the present invention has a large isolation group in the middle of its molecule, which enables its molecules to be arranged in an orderly manner at the gas-liquid interface; at the same time, the side chain has six hydroxyl groups and quaternary ammonium salt groups, which can greatly improve the fluidity of the liquid film during the flotation process and avoid the mineral foam from being too viscous.
[0039] (2) The triazine hexameric quaternary ammonium salt compound provided by this invention contains six positively charged quaternary ammonium groups. During the flotation process, these active groups can undergo strong multi-point electrostatic adsorption with the large number of negative charges exposed on the cleavage surfaces of silicate minerals. This multi-point anchoring effect greatly enhances the adhesion and intensity of the reagent on the surface of the target mineral, making its collecting ability far exceed that of traditional single-headed amine collectors, thus obtaining high-grade and high-recovery concentrates with extremely low reagent consumption.
[0040] (3) Traditional aliphatic amine collectors are prone to crystallization and precipitation at room temperature, requiring the heating of the slurry or the addition of large amounts of frothers / solvents. The triazine hexameric quaternary ammonium salt compounds of this invention are highly hydrophilic as collectors, and still have excellent solubility and dispersibility in water at room temperature or even low temperatures (such as 5℃~10℃). This directly eliminates the need for slurry heating in flotation operations during winter or in cold regions, completely breaks through the energy consumption bottleneck of traditional processes, and significantly reduces the energy cost of industrial production.
[0041] (4) The triazine hexameric quaternary ammonium salt compounds of the present invention have a large molecular volume and a rigid triazine ring skeleton. Their unique spatial configuration forms a more dense hydrophobic layer after adsorption on the mineral surface. At the same time, their strong steric hindrance effect can effectively block the covering of fine mineral slime on the surface of silicate minerals, which greatly improves the tolerance of the flotation system to mineral slime and can still maintain excellent flotation indicators even when the raw ore has a high slime content. Attached Figure Description
[0042] Figure 1 The molecular structure of THQ-pm prepared in Example 1 of this invention is shown.
[0043] Figure 2 The infrared spectrum of THQ-pm prepared in Example 1 of this invention.
[0044] Figure 3 The THQ-8 molecular structure prepared in Example 2 of this invention.
[0045] Figure 4 The infrared spectrum of THQ-8 prepared in Example 2 of this invention.
[0046] Figure 5 The molecular structure of THQ-10 prepared in Example 3 of this invention.
[0047] Figure 6 The infrared spectrum of THQ-10 prepared in Example 4 of this invention.
[0048] Figure 7 This is a flow chart of the flotation process in Example 5. Detailed Implementation
[0049] The technical solutions of the embodiments of the present invention will be clearly and completely described below, but are not limited to the embodiments.
[0050] Example 1
[0051] Preparation of THQ-pm
[0052] Under nitrogen protection, triethylamine (2.8 mL, 0.0201 mol) and melamine (5.000 g, 0.0397 mol) were dissolved in N,N-dimethylformamide (31.000 g, 0.4241 mol) in a three-necked flask equipped with a stirrer at room temperature. Epichlorohydrin (31.500 g, 0.3405 mol) was then slowly added dropwise to the flask at a rate of 5 drops / min. After the addition was complete, the mixture was heated to 105°C and refluxed at this temperature for 48 hours. After the reaction was complete, the solution was concentrated under reduced pressure using a rotary evaporator. The resulting residual solid was washed once with n-hexane and then recrystallized twice with acetone. After vacuum drying, a brown solid intermediate was obtained.
[0053] The intermediate prepared above (3.000 g, 0.0015 mol) was added to a three-necked flask, followed by distilled water (45 mL), N,N-dimethylformamide (45 mL), and sodium hydroxide aqueous solution (0.500 mol / L, 10 mL) to dissolve it. Under nitrogen protection and vigorous stirring, N,N-dimethylbenzylamine (1.42 g, 0.0105 mol), pre-dissolved in ethanol (30 mL), was slowly added to the reaction mixture. The reaction system was then heated to 85°C and refluxed for 16 hours. After the reaction was complete, the solvent was removed by vacuum distillation. The resulting solid residue was washed once with n-hexane and then recrystallized twice with acetone. The product was dried under vacuum at 65°C to obtain the final THQ-pm product. The molecular structure and infrared spectrum are shown below. Figure 1 , Figure 2 As shown.
[0054] Table 1 THQ-pm Infrared Spectroscopic Analysis
[0055]
[0056] Table 1 confirms the successful preparation of THQ-pm.
[0057] Example 2
[0058] Preparation of THQ-8
[0059] Under nitrogen protection, triethylamine (2.8 mL, 0.0201 mol) and melamine (5.000 g, 0.0397 mol) were dissolved in N,N-dimethylformamide (31.000 g, 0.4241 mol) in a three-necked flask equipped with a stirrer at room temperature. Epichlorohydrin (31.500 g, 0.3405 mol) was then slowly added dropwise to the flask at a rate of 5 drops / min. After the addition was complete, the mixture was heated to 105°C and refluxed at this temperature for 48 hours. After the reaction was complete, the solution was concentrated under reduced pressure using a rotary evaporator. The resulting residual solid was washed once with n-hexane and then recrystallized twice with acetone. After vacuum drying, a brown solid intermediate was obtained.
[0060] The intermediate prepared above (3.000 g, 0.0015 mol) was added to a three-necked flask, followed by distilled water (45 mL), N,N-dimethylformamide (45 mL), and sodium hydroxide aqueous solution (0.500 mol / L, 10 mL) to dissolve it. Under nitrogen protection and vigorous stirring, N,N-dimethyloctylamine (1.65 g, 0.0105 mol), pre-dissolved in ethanol (30 mL), was slowly added to the reaction mixture. The reaction system was then heated to 85°C and refluxed for 16 hours. After the reaction was complete, the solvent was removed by vacuum distillation. The resulting residual solid was washed once with n-hexane and then recrystallized twice with acetone. The product was dried under vacuum at 65°C to obtain THQ-8. The molecular structure and infrared spectrum are shown below. Figure 3 , Figure 4 As shown.
[0061] Table 2 Infrared Spectral Analysis of THQ-8
[0062]
[0063] Table 2 confirms the successful preparation of THQ-8.
[0064] Example 3
[0065] Preparation of THQ-10
[0066] Under nitrogen protection, triethylamine (2.8 mL, 0.0201 mol) and melamine (5.000 g, 0.0397 mol) were dissolved in N,N-dimethylformamide (31.000 g, 0.4241 mol) in a three-necked flask equipped with a stirrer at room temperature. Epichlorohydrin (31.500 g, 0.3405 mol) was then slowly added dropwise to the flask at a rate of 5 drops / min. After the addition was complete, the mixture was heated to 105°C and refluxed at this temperature for 48 hours. After the reaction was complete, the solution was concentrated under reduced pressure using a rotary evaporator. The resulting residual solid was washed once with n-hexane and then recrystallized twice with acetone. After vacuum drying, a brown solid intermediate (Formula 3) was obtained.
[0067] The intermediate prepared above (3.000 g, 0.0015 mol) was added to a three-necked flask, followed by distilled water (45 mL), N,N-dimethylformamide (45 mL), and sodium hydroxide aqueous solution (0.500 mol / L, 10 mL) to dissolve it. Under nitrogen protection and vigorous stirring, N,N-dimethyldecylamine (1.95 g, 0.0105 mol), pre-dissolved in ethanol (30 mL), was slowly added to the reaction mixture. The reaction system was then heated to 85°C and refluxed for 16 hours. After the reaction was complete, the solvent was removed by vacuum distillation. The resulting residual solid was washed once with n-hexane and then recrystallized twice with acetone. The product was dried under vacuum at 65°C to obtain THQ-10. The molecular structure and infrared spectrum are shown below. Figure 5 , Figure 6 As shown.
[0068] Table 3 Infrared Spectral Analysis of THQ-10
[0069]
[0070] Table 3 confirms the successful preparation of THQ-10.
[0071] Example 4
[0072] Evaluation of the foaming properties of triazine hexameric quaternary ammonium compounds
[0073] The foaming performance and foam stability of triazine hexameric quaternary ammonium compounds as collectors for silicate minerals were quantitatively evaluated using a DFA100 foam analyzer. In the two-phase (gas-liquid) system test, 40 mL of collector solution of the same concentration was prepared using deionized water. Compressed air was introduced into the solution through a porous filter at a constant flow rate of 0.3 L / min for a certain period of time to generate foam. Key parameters evaluated included the maximum foam height recorded immediately after the gas flow stopped and the foam half-life. All experiments were conducted at room temperature (25°C), and each condition was repeated at least three times to ensure data reproducibility.
[0074] In this experiment, THQ-8 prepared in Example 2 was used to test its bubble performance. The results are shown in Table 4. It can be seen that the half-life t of THQ-8 is... 50% It is significantly smaller than DDA and PDDA (N1,N3-bisdodecyl-N1,N1,N3,N3-tetramethylpropane-1,3-diammonium chloride), which is beneficial for the use of THQ-8 in flotation.
[0075] Table 4 Bubble Performance Test
[0076]
[0077] Example 5
[0078] Flotation experiments of triazine hexameric quaternary ammonium salts as collectors on a lithium mica ore deposit in Jiangxi Province
[0079] A lithium mica ore sample from Jiangxi Province contained 0.61 wt% Li2O. The grinding fineness of the ore was -200 mesh, accounting for 68 wt%. When using triazine hexameric quaternary ammonium salt as a collector, the roughing pH was adjusted to 5.0. After one roughing flotation process, the flotation results are shown in Table 5.
[0080] Table 5. Flotation experiments of a lithium mica ore in Jiangxi Province
[0081]
[0082] Flotation results showed that DDA and PDDA could not enrich lepidolite, and the Li2O grade only increased slightly after flotation. At the same time, the Li2O recovery rate was lower than that of triazine hexameric quaternary ammonium salt collectors such as THQ-8 and THQ-10.
Claims
1. The application of a triazine hexameric quaternary ammonium salt compound as a flotation collector for silicate minerals, characterized in that: The triazine hexameric quaternary ammonium salt compound has the structural formula of Formula 1: ； Formula 1; Where R is a quaternary ammonium salt group.
2. The application according to claim 1, characterized in that: The R has the structural formula of Equation 2: ； Formula 2; in, The bonding sites are represented by X, which represents the equilibrium anion. R1 is an alkylene group, and R2 to R4 are the same or different alkyl or aryl groups.
3. The application according to claim 2, characterized in that: R1 is methylene, R2 and R4 are selected from the same C1-C3 straight-chain alkyl group, and R3 is selected from C1-C3 alkyl group. 18 Straight-chain alkyl or C6-C7 aromatic alkyl.
4. The application according to any one of claims 1 to 3, characterized in that: The application process includes the following steps: S1 involves grinding and slurry preparation of silicate mineral ore to obtain a slurry; S2 adds flotation reagents, including triazine hexameric quaternary ammonium salt compounds, to the slurry for flotation and collects the flotation concentrate.
5. The application according to claim 4, characterized in that: The silicate minerals include at least one of lepidolite, quartz, potassium feldspar, sodium feldspar, and spodumene.
6. The application according to claim 5, characterized in that: The grinding process controls the mineral content to be -200 mesh, with the minerals comprising 55-85 wt%.
7. The application according to claim 4, characterized in that: The slurry concentration is controlled at 25-45 wt%, and the pH is 5-10.
8. The application according to claim 4, characterized in that: The grinding process is followed by a desliming process. Preferably, the desliming process is a settling process, which is repeated 2 to 3 times, with each settling time being 3 to 5 minutes.
9. The application according to claim 4, characterized in that: The flotation includes at least one roughing process, wherein the amount of the triazine hexameric quaternary ammonium salt compound used in the roughing process is 10~1500 g / t relative to the raw ore.