Modified ammonium salt collector and preparation method and application thereof

Abstract

The application discloses a modified ammonium salt collecting agent and a preparation method and application thereof, and belongs to the technical field of ore flotation collecting agents. + · ‑ OOC C 17 H 33 , R is C 12~14 alkyl, and the modified ammonium salt collecting agent is obtained by the reaction of a cationic collecting agent, hydrochloric acid and an anionic collecting agent. The modified ammonium salt collecting agent with an amphoteric surfactant structure is prepared by a chemical synthesis method, can be subjected to multiple actions with the surface active sites of aluminosilicate minerals, and realizes accurate identification and efficient collection of aluminum-containing minerals.

Description

Technical Field

[0001] This invention relates to the field of ore flotation collectors, and in particular to a modified ammonium salt collector, its preparation method, and its application. Background Technology

[0002] my country is a major alumina producer, but its bauxite resources are relatively poor, mainly consisting of gibbsite-type bauxite, characterized by high aluminum, high silica, and a low aluminum-silicon ratio. With the continuous depletion of high-quality bauxite resources, the development and utilization of large quantities of medium- and low-grade bauxite with an aluminum-silicon ratio below 5 has become an urgent task to ensure the resource security of my country's aluminum industry and meet national strategic needs. However, the main gangue minerals in these ores are layered silicate minerals such as kaolinite, illite, and pyrophyllite, which are extremely similar to the target mineral, gibbsite, in crystal structure, surface chemical properties, and floatability, making it difficult to achieve efficient separation using conventional beneficiation methods. How to efficiently remove silicate gangue and increase the aluminum-silicon ratio is key to solving the problem of utilizing medium- and low-grade bauxite in my country, and it has long been a hot topic and a difficult issue in the mineral processing field.

[0003] Currently, bauxite desilication flotation mainly employs two technical routes: "direct flotation" and "reverse flotation," both of which hinge on the development and control of flotation reagents. Direct flotation primarily uses fatty acid collectors to collect gibbsite monohydrate, while simultaneously using depressants to suppress silicate gangue. Commonly used depressants include sodium hexametaphosphate, sodium silicate, starch, and its derivatives. However, these depressants generally suffer from insufficient selectivity, sensitivity to slime, and significant interference from unavoidable ions, leading to high reagent consumption and fluctuations in flotation parameters. Reverse flotation primarily uses cationic amine collectors to collect silicate gangue. However, single amine collectors suffer from drawbacks such as high foam viscosity, poor selectivity, sensitivity to pulp pH, and decreased activity at low temperatures, severely limiting the industrial application of reverse flotation.

[0004] To overcome the limitations of single-agent agents, researchers have attempted to combine different types of collectors, such as cationic amines with anionic fatty acids. Existing compounding techniques are mostly simple physical mixtures, with their mechanism of action based on the formation of mixed micelles, enhancing surface activity and collecting capacity through synergistic effects. However, this physical mixing method has limited ability to identify differences in mineral surface properties, especially for aluminosilicate minerals with similar lattice structures and similar surface properties, making truly precise separation difficult. Summary of the Invention

[0005] The main objective of this invention is to provide a modified ammonium salt collector, its preparation method, and its application, thereby solving the technical problems in existing flotation processes where physically compounded composite collectors have poor activity and limited ability to identify differences on mineral surfaces, resulting in poor selectivity and unsatisfactory separation effects.

[0006] To achieve the above objectives, the present invention provides a modified ammonium salt collector having the following general structural formula: RNH3 + · - OOC C 17 H 33 R is C 12~14 The alkyl group, wherein the modified ammonium salt collector is obtained by reacting a cationic collector, hydrochloric acid and an anionic collector.

[0007] In some embodiments of the present invention, the cationic collector reacts with the hydrochloric acid to obtain an intermediate, and the intermediate reacts with the anionic collector to obtain the modified ammonium salt collector.

[0008] In some embodiments of the present invention, the cationic collector includes at least one of dodecylamine, tetradecylamine, and isododecylamine.

[0009] In some embodiments of the present invention, the anionic collector includes at least one of sodium oleate, oxidized paraffin soap, and tal oil soap.

[0010] In some embodiments of the present invention, the cationic collector is 3.5 to 4.5 parts by weight, the anionic collector is 0.5 to 1.5 parts by weight, and the hydrochloric acid is 3.5 to 4.5 parts by weight. And / or, the hydrochloric acid has a mass fraction of 36% to 38%.

[0011] In some embodiments of the present invention, the mass ratio of the cationic collector, the anionic collector, and the hydrochloric acid is 4:1:4.

[0012] In some embodiments of the present invention, the modified ammonium salt collector is an oily paste.

[0013] This invention also provides a method for preparing a modified ammonium salt collector, the method comprising the following steps: Hydrochloric acid was added to the cationic collector, and the first stirring reaction yielded an intermediate. An anion collector was added to the intermediate, and a second stirring reaction was carried out to obtain the reaction product. The reaction product was allowed to stand and mature to obtain a modified ammonium salt collector.

[0014] In some embodiments of the present invention, the reaction temperature of the first stirring reaction is 20°C to 30°C and the reaction time is 10 min to 20 min; and / or, the reaction temperature of the second stirring reaction is 20°C to 30°C and the reaction time is 30 min to 60 min.

[0015] The present invention also provides the application of the modified ammonium salt collector as described above in the ore flotation process.

[0016] The beneficial effects that this invention can achieve are: This invention abandons the traditional approach of flotation of target ores using physically compounded reagents. Instead, it employs a chemical synthesis method to neutralize cationic and anionic collectors in a hydrochloric acid medium, generating in situ a modified ammonium salt collector capable of achieving a precise stoichiometric ratio. The cationic collector possesses cationic surfactant properties, and the intermediate obtained after mixing with hydrochloric acid also exhibits cationic surfactant properties. The anionic collector, possessing anionic surfactant properties, binds to this intermediate through electrostatic and hydrophobic interactions, resulting in a neutralization reaction that generates a modified ammonium salt collector with a precise stoichiometric ratio and incorporating an amphoteric surfactant structure.

[0017] The modified ammonium salt collector exhibits fundamentally altered aggregation states, critical micelle concentrations, and adsorption configurations on different mineral surfaces. It can interact with specific active sites on mineral surfaces, particularly aluminosilicate minerals, through multiple mechanisms. For example, positively charged amine groups can adsorb onto negatively charged mineral surfaces via electrostatic interactions, while negatively charged carboxylic acid groups can interact with Al groups on mineral surfaces through chemical coordination. 3+ Si-O - Through chemical adsorption and hydrogen bonding of surface hydroxyl groups, it can accurately identify and efficiently collect impurity minerals, especially for the deep removal of trace impurities such as aluminum and potassium, so as to separate and purify the target minerals.

[0018] This invention provides a novel approach to the development of collectors based on molecular structure design, offering a solid theoretical foundation and clear directional guidance for further optimization of agent structures and the development of a series of highly efficient collectors in the future. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0020] Figure 1 This is a SEM image of the ore sample (original sample) in Example 1 of the present invention; Figure 2 The above is the EDS energy spectrum of the ore sample (original sample) in Example 1 of this invention; Figure 3The image shows the FT-IR infrared spectrum of the ore sample (original sample) in Example 1 of this invention; Figure 4 This is an SEM image of the upper foam product after flotation in Example 1 of the present invention; Figure 5 This is the EDS energy spectrum of the upper foam product after flotation in Example 1 of the present invention; Figure 6 This is an SEM image of the lower sediment product after flotation in Example 1 of the present invention; Figure 7 This is the EDS energy spectrum of the lower precipitate product after flotation in Example 1 of the present invention; Figure 8 This is the FT-IR infrared spectrum of the upper foam product after flotation in Example 1 of the present invention; Figure 9 This is the FT-IR infrared spectrum of the lower precipitate product after flotation in Example 1 of the present invention.

[0021] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0022] It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0023] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0024] In this invention, descriptions involving "first," "second," etc., are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. Furthermore, the technical solutions of the various embodiments can be combined with each other, but only on the basis of being achievable by those skilled in the art. If the combination of technical solutions is contradictory or impossible to implement, such a combination should be considered non-existent and not within the scope of protection claimed by this invention.

[0025] To overcome the shortcomings of single collectors, researchers have attempted to combine different types of collectors, such as combining cationic amine collectors with anionic fatty acid collectors. However, existing compounding techniques are mostly simple physical mixing methods, which have limited ability to identify differences in mineral surface properties, especially for aluminosilicate minerals with similar crystal structures and surface properties, making it difficult to achieve truly precise separation.

[0026] In view of this, the present invention provides a modified ammonium salt collector having the following general structural formula: RNH3 + · - OOC C 17 H 33 R is C 12~14 The alkyl-modified ammonium salt collector is obtained by reacting a cationic collector, hydrochloric acid, and an anionic collector.

[0027] Cationic collectors possess the properties of cationic surfactants, and the intermediates obtained from their reaction with hydrochloric acid also possess the properties of cationic surfactants. In contrast, anionic collectors possess the properties of anionic surfactants. After combining with the intermediates through electrostatic and hydrophobic interactions, a neutralization reaction occurs, generating a modified ammonium salt collector with a defined stoichiometric ratio and containing an amphoteric surfactant structure.

[0028] This invention abandons the traditional approach of flotation of target ores using physically compounded reagents. The modified ammonium salt collector prepared through the above chemical synthesis method achieves an amphoteric surfactant structure, capable of forming a composite micelle structure in aqueous solution. The hydrophobic tail chains of the cationic and anionic collector portions of the modified ammonium salt collector aggregate through hydrophobic interactions to form the micelle core, while the polar heads with opposite charges form a mixed arrangement on the micelle surface, resulting in active sites with both positive and negative charges on the micelle surface. Based on these fundamental changes in molecular structure and aggregation morphology, the critical micelle concentration and adsorption configuration of this modified ammonium salt collector have significantly changed, enabling it to exhibit multiple synergistic effects with specific active sites on the mineral surface—positively charged active groups adsorb onto negatively charged mineral regions through electrostatic interactions, while negatively charged active groups interact with Al on the mineral surface through chemical coordination. 3+ Si-O - The composite micelles form chemisorption and hydrogen bonding with surface hydroxyl groups. When the composite micelles come into contact with the mineral surface, the above-mentioned dual mechanisms of electrostatic interaction and chemisorption act simultaneously on different active areas of the mineral surface, forming a more robust and dense hydrophobic adsorption layer than a single collector. This significantly improves the collecting capacity and selectivity, enabling accurate identification and efficient collection of trace impurity minerals such as aluminum and potassium, and achieving the purpose of deep impurity removal and separation and purification of target minerals.

[0029] This invention provides a novel approach to the development of collectors based on molecular structure design, offering a solid theoretical foundation and clear directional guidance for further optimization of agent structures and the development of a series of highly efficient collectors in the future.

[0030] Cationic collectors endow modified ammonium salt collectors with cationic surfactant properties, enabling them to provide positively charged active groups that adsorb onto negatively charged mineral regions on the surface via electrostatic interactions.

[0031] In some embodiments, the cationic collector includes at least one of dodecylamine, tetradecylamine, and isododecylamine. These cationic collectors possess cationic surfactant activity, providing positively charged amine groups to the modified ammonium salt collector. Through electrostatic adsorption, they adsorb onto negatively charged minerals, achieving precise identification and efficient collection of impurity minerals. In particular, they can deeply remove trace impurities such as aluminum and potassium, achieving the purpose of separation and purification to obtain the target mineral.

[0032] For example, the cationic collector is dodecylamine, which reacts with hydrochloric acid to give the intermediate dodecylamine hydrochloride, providing a reaction basis for subsequent neutralization reactions with the anionic collector.

[0033] In some embodiments, the intermediate obtained by reacting a cationic collector with hydrochloric acid has the following general structural formula: RNH3 + Cl - R is C 12~14 Alkyl groups.

[0034] Anionic collectors possess the properties of anionic surfactants, providing negatively charged groups for modified ammonium salt collectors, enabling them to chemically coordinate with Al on the mineral surface. 3+ Si-O - Through chemical adsorption and hydrogen bonding of surface hydroxyl groups, it can accurately identify and efficiently collect impurity minerals, especially for the deep removal of trace impurities such as aluminum and potassium, so as to separate and purify the target minerals.

[0035] In some embodiments, the anionic collector includes at least one of sodium oleate, oxidized paraffin soap, and talcum oil soap; exemplaryly, the anionic collector is sodium oleate. The above anionic collector readily undergoes a neutralization reaction with an intermediate obtained from the reaction of a cationic collector and hydrochloric acid to generate a modified ammonium salt collector with an amphoteric surfactant structure, providing a negatively charged carboxylic acid group that interacts with Al on the mineral surface through chemical coordination. 3+ Si-O - Through chemical adsorption and hydrogen bonding of surface hydroxyl groups, it can accurately identify and efficiently collect impurity minerals, especially for the deep removal of trace impurities such as aluminum and potassium, so as to separate and purify the target minerals.

[0036] In some embodiments, the cationic collector is 3.5 to 4.5 parts by weight, the anionic collector is 0.5 to 1.5 parts, and the hydrochloric acid is 3.5 to 4.5 parts. Exemplarily, the cationic collector is 3.5, 3.8, 3.9, 4, 4.1, 4.2, 4.3, 4.4, or 4.5 parts; the anionic collector is 0.5, 0.7, 0.8, 0.9, 1, 1.2, 1.3, 1.4, or 1.5 parts; and the hydrochloric acid is 3.5, 3.8, 3.9, 4, 4.2, or 4.5 parts, etc. This invention uses a chemical synthesis method to prepare modified ammonium salt collectors. By adjusting the mass ratio of cationic collectors, anionic collectors, and hydrochloric acid, the reaction can follow the required stoichiometric ratio, giving the modified ammonium salt collectors better molecular structural stability. This promotes the formation of specific aggregation states and micellar structures in the solution, resulting in specific adsorption configurations on the mineral surface, thereby achieving accurate identification and efficient collection of target minerals.

[0037] In some embodiments, the mass ratio of cationic collector, anionic collector, and hydrochloric acid is 4:1:4, which is beneficial for the intermediate generated by the cationic collector and hydrochloric acid to form a stable composite micelle structure with charge matching with the anionic collector. At the same time, the excess hydrochloric acid ensures the complete protonation of the cationic collector and maintains a suitable acidic environment, thereby achieving efficient and selective adsorption and separation of aluminosilicate gangue minerals.

[0038] In some embodiments, the mass fraction of hydrochloric acid is 36% to 38%, which can be 36%, 36.5%, 37%, 37.5%, 38%, etc. On the one hand, this concentration range ensures that dodecylamine is completely protonated to form a stable cationic active component, and also provides a suitable neutralization reaction medium; on the other hand, this concentration range avoids the introduction of too much water due to excessively low concentration, which would affect the morphology and stability of the product.

[0039] In some embodiments, the modified ammonium salt collector is an oily paste. This oily paste form provides excellent dispersibility and mass transfer efficiency in the slurry, which helps to shorten the interaction time between the reagent and the mineral surface, thereby improving flotation efficiency. Unlike existing amine collectors, which are mostly supplied in solid or liquid form and require on-site acidification, the modified ammonium salt collector, with its superior ease of use and stability, can be directly added to the flotation cell for flotation operations without any pretreatment. This formulation design not only simplifies on-site reagent management and avoids reagent performance fluctuations caused by improper on-site acidification conditions, but also significantly reduces the health hazards of reagent dust to operators.

[0040] This invention also provides a method for preparing a modified ammonium salt collector, the method comprising the following steps: S10. Add hydrochloric acid to the cationic collector and stir the reaction for the first time to obtain the intermediate. S20. Add an anion collector to the intermediate and stir the reaction a second time to obtain the reaction product. S30. The reaction product was allowed to stand and mature to obtain the modified ammonium salt collector.

[0041] In some embodiments, the reaction temperature of the first stirring reaction is 20℃~30℃, and the reaction time is 10min~20min. For example, the reaction temperature can be 20℃, 21℃, 22℃, 23℃, 24℃, 25℃, 26℃, 27℃, 28℃, 29℃, 30℃, etc., and the reaction time can be 10min, 12min, 14min, 15min, 16min, 18min, 20min, etc.

[0042] In some embodiments, the reaction temperature of the second stirring reaction is 20℃~30℃, which can be 20℃, 22℃, 25℃, 28℃, 30℃, etc., and the reaction time is 30min~60min, which can be 30min, 35min, 40min, 45min, 50min, 55min, 60min, etc.

[0043] In step S30, the reaction product is allowed to stand and mature to obtain a modified ammonium salt collector. The standing and maturation process helps to improve the structural stability and dispersibility of the modified ammonium salt collector in flotation applications, thereby improving the flotation effect.

[0044] In some embodiments, the settling time is 30 min to 60 min. For example, the settling time can be 30 min, 40 min, 50 min, 60 min, etc.

[0045] In some embodiments, the temperature for static curing is 25°C to 30°C.

[0046] In some embodiments, the modified ammonium salt collector from step S30 is subjected to the following treatment: drying and pulverizing to obtain a solid powder that is easy to store.

[0047] In some embodiments, the drying temperature is 40°C to 50°C.

[0048] The modified ammonium salt collector of the present invention can be applied to the silica sand flotation purification process, and silica sand products can be obtained by flotation purification of minerals using the modified ammonium salt collector.

[0049] The modified ammonium salt collector of the present invention is suitable for laboratory-scale micro-flotation experiments and can also be directly scaled up for industrial-scale production.

[0050] The technical solution of the present invention will be further described in detail below with reference to specific embodiments. It should be understood that the following specific embodiments are only used to explain the present invention and are not intended to limit the present invention.

[0051] 1. Preparation of modified ammonium salt collector Example 1 S10. Weigh the raw materials according to Table 9, place the cationic collector in the reactor, slowly add hydrochloric acid under stirring at 400 r / min, and carry out the first stirring reaction at 400 r / min for 15 min at 25℃ to obtain the intermediate. S20. Add an anion collector to the intermediate and stir the mixture for a second time at 400 r / min at 25°C for 30 min until the reaction is complete to obtain the reaction product. S30. The reaction product was allowed to stand at 25°C for 45 minutes to mature, thus obtaining the modified ammonium salt collector.

[0052] 2. Flotation test conditions Flotation tests were conducted on an XFD-II type hanging trough flotation machine (40 mL tank volume). For each test, 2.0 g of ore sample was weighed and added to the flotation cell along with 35 mL of deionized water. The mixture was stirred for 1 min to form a homogeneous slurry. The pH of the slurry was adjusted to 4.0 with HCl or NaOH. After stirring for 2 min, the modified ammonium salt collector from Example 1 was added at a dosage of 35 mg per L of slurry. The mixture was stirred for 3 min, and finally, the bubbles were manually skimmed off for 3 min.

[0053] The upper foam product and the lower sediment product obtained by flotation are filtered, dried and weighed respectively for subsequent testing.

[0054] 3. Original sample analysis (before flotation) (3.1) ICP-OES elemental analysis After digestion, the contents of major elements were determined by inductively coupled plasma atomic emission spectrometry (ICP-AES). The results are shown in Table 1.

[0055] Table 1

[0056] From Table 1, we can see that: The ore sample contains approximately 45.58% SiO2, 1.00% Al2O3, and 0.23% Fe2O3, classifying it as a typical high-iron, high-alumina quartz sand.

[0057] (3.2) SEM morphology analysis and EDS elemental analysis SEM morphology analysis was performed using a Hitachi SU8010 field emission scanning electron microscope with an accelerating voltage of 5.0 kV. The samples were sputter-coated with gold before testing.

[0058] SEM images of the ore samples are shown below. Figure 1 The ore sample consists of irregular aggregates with a size exceeding 100 μm, with sharp edges and numerous flat, plate-like structures, consistent with brittle fracture characteristics.

[0059] EDS plot of ore sample is shown below Figure 2 The elemental composition results are shown in Table 2. Analysis shows that the main phase of the ore sample is SiO2 (Si 47.47 wt%, O 41.72 wt%), and it also contains Al (3.30 wt%), Fe (1.85 wt%) and small amounts of K, Na, Mg, etc., which further confirms the presence of aluminosilicate impurities (such as mica and feldspar).

[0060] Table 2

[0061] (3.3) FT-IR infrared spectroscopy analysis FT-IR infrared spectroscopy analysis was performed on a Nicolet (detector DTGS) infrared spectrometer, with a wavenumber range of 4000–400 cm⁻¹. -1 .

[0062] The FT-IR spectrum of the ore sample is shown below. Figure 3 The FT-IR spectrum shows typical silicate characteristics: 1058 cm⁻¹ -1 The vibration at this point is an asymmetric stretching vibration of Si-O-Si, 885 cm⁻¹. -1 and 594 cm -1 For Si-O bending and network deformation mode, 3670 cm -1 The broad peaks nearby indicate surface hydroxyl groups (-OH), 2977 / 2900 cm⁻¹ -1 The small peak indicates organic CH stretching vibration (trace contamination). FT-IR spectra confirm that the ore sample has a silicate glass / mineral structure with surface hydration.

[0063] 4. Analysis of flotation products After flotation, the upper foam product and the lower precipitate product were analyzed by ICP-OES, SEM-EDS and FT-IR to evaluate the selective separation effect of the modified ammonium salt collector in Example 1.

[0064] (4.1) ICP-OES elemental analysis (after flotation) ICP-OES elemental analysis was performed on the original ore sample, the upper froth, and the lower sediment after flotation. The IPC test analysis process is shown in Table 3, and the comprehensive analysis results are shown in Table 4.

[0065] Table 3

[0066] Table 4

[0067] From Tables 3 and 4, we can see that: The Al content in the upper foam product (2.61%) was 2.6 times that of the original sample (1.00%) and nearly 5 times that of the lower sediment (0.53%), indicating that Al was selectively enriched in the foam product.

[0068] The Si content in the lower sediment layer increased slightly, and the Si / Al ratio increased from 45.5 to 85.7, indicating that aluminum-poor minerals such as quartz were mainly retained in the tailings.

[0069] The Fe content decreased in both the upper and lower layers (from 0.23% to about 0.17%), which is equivalent to a reduction of about 1000 ppm in Fe2O3, indicating that iron impurities were also partially removed.

[0070] (4.2) SEM-EDS analysis (after flotation) The upper foam and lower sediment layers after flotation were analyzed by SEM-EDS.

[0071] SEM image of the upper foam layer is shown below. Figure 4 The EDS elemental analysis process and results are shown in Table 5 and Figure 5 .

[0072] SEM images of the lower sediment layer are shown below. Figure 6 The EDS elemental analysis process and results are shown in Table 6 and Figure 7 .

[0073] Table 5

[0074] Depend on Figure 4 We can know that: Upper foam: SEM images show a large number of fine, flaky particles (mica characteristics) attached to the surface and pores of coarse, angular quartz particles.

[0075] Depend on Figure 5The EDS analysis results in Table 5 show that, in addition to Si and O, high concentrations of Al (9.96 wt%), K (3.73 wt%), and Fe (5.18 wt%) were detected, confirming that aluminosilicates such as mica / feldspar were entrained or partially floated into the foam, consistent with the Al enrichment in the ICP-OES elemental analysis in Tables 3 and 4.

[0076] Table 6

[0077] Depend on Figure 6 We can know that: Lower sediment: SEM images show a large number of well-defined, large and thin flaky particles (typical mica layered structure), indicating that the mica was effectively discharged into the tailings.

[0078] Depend on Figure 7 The EDS analysis results in Table 6 show that Si (30.86 wt%) and O (47.68 wt%) are dominant in the EDS analysis (Table 5), the Al content is reduced to 4.97 wt%, and K is below the detection limit, confirming that aluminosilicate impurities are significantly reduced.

[0079] (4.3) FT-IR analysis (after flotation) FT-IR analysis was used to analyze the upper foam and lower sediment.

[0080] The FT-IR spectrum of the upper foam is shown below. Figure 8 : Figure 8 It shows approximately 3700–3200 cm. -1 Wide absorption (OH / NH stretching), 3000–2850 cm⁻¹ -1 Weak absorption (CH, alkyl structure), 1700–1720 cm⁻¹ -1 A C=O stretching peak appears nearby, at 1600–1450 cm⁻¹. -1 The aromatic rings are C=C or NH bent. These characteristics indicate that the amine and carboxylic acid groups in the modified ammonium salt collector molecule of Example 1 have been successfully adsorbed onto the mineral surface, consistent with the structure of the amphoteric surfactant.

[0081] The FT-IR spectrum of the lower precipitate is shown below. Figure 9 : Figure 9 The characteristic peaks of Si-O-Si (1134, 1033 cm⁻¹) are still visible in the middle. -1 However, the absorption by the organic functional groups is weak, indicating that the modified ammonium salt collector in Example 1 mainly acts on the aluminum-containing minerals being floated, and has less adsorption on quartz in the tailings.

[0082] Analysis of Example 1 shows that after flotation, the original Al content of the ore sample was 1.00%, while the treated content was 2.61% in the upper layer and 0.53% in the lower layer, with the upper layer content being nearly five times that of the lower layer, indicating that Al was mainly enriched in the upper product. The original Si content was 45.58%, while the treated content was 43.92% in the upper layer and 45.28% in the lower layer, indicating that Si was relatively enriched in the lower layer. This demonstrates that the modified ammonium salt collector of this invention can achieve accurate identification and efficient separation of aluminum-bearing minerals and gangue minerals in the flotation process. Simultaneously, the original Fe content was 0.23%, while the treated content was 0.18% in the upper layer and 0.17% in the lower layer, a reduction of approximately 0.06%, which translates to approximately 1000 ppm Fe₂O₃. The Fe content in the silica sand was reduced in both the upper and lower layers, achieving directional enrichment of the target element Al while removing a small amount of Fe impurities.

[0083] 5. Comparative Example Comparative Examples 1 and 2 below use the exact same ore samples, flotation equipment, processes and testing methods as Example 1, only the collector system is different.

[0084] Comparative Example 1: Comparative Example 1 uses dodecylamine (DDA) as the collector instead of the modified ammonium salt collector in Example 1, and the amount used is the same as that of the modified ammonium salt collector in Example 1. The results of Comparative Example 1 are shown in Table 7.

[0085] Table 7

[0086] From Table 7, we can see that: In Comparative Example 1, the single collector dodecylamine could not selectively enrich Al, and the Al content in the foam and tailings was almost equal (about 1.1%).

[0087] Comparative Example 2: Comparative Example 2 follows the same procedure as Example 1, but without the addition of hydrochloric acid. Dodecylamine and sodium oleate are mixed by simple physical mixing at a mass ratio of 4:1, and then stirred at 25°C for 10 min before being directly added to the slurry as a collector for flotation. The total amount used for flotation is the same as in Example 1. The results are shown in Table 8.

[0088] Table 8

[0089] From Table 8, we can see that: Although Comparative Example 2 achieved partial separation (Al enrichment ratio of approximately 2.1) through physical mixing of the collector, it was far lower than the 4.9-fold enrichment ratio of Example 1.

[0090] By combining Examples 1 and 2, we can see that: This invention utilizes a modified ammonium salt collector synthesized through a pre-neutralization reaction to achieve an Al content in the upper foam layer (2.61%) that is nearly five times higher than that in the lower precipitate layer (0.53%), thus realizing highly efficient and selective enrichment of Al in aluminosilicate minerals. Furthermore, SEM-EDS testing can visually demonstrate that layered aluminosilicates such as mica are effectively discharged into the tailings. FT-IR testing confirms that the modified ammonium salt collector of Example 1 acts on the surface of the target mineral through chemical adsorption, demonstrating that the modified ammonium salt collector of Example 1 has excellent selective separation ability for aluminosilicate minerals, and its technical effect is significantly better than that of single amines and physically mixed collectors.

[0091] 6. Examples 2 to 5 Examples 2 to 5 prepared modified ammonium salt collectors according to the method of Example 1, except that the types, mass fractions, and reaction conditions of the cationic collector, hydrochloric acid, and anionic collector were different. Among them: In Example 2, the mass ratio of dodecylamine, sodium oleate, and hydrochloric acid was 4.5:1.5:4.5. In Example 3, the mass ratio of dodecylamine, sodium oleate, and hydrochloric acid was 3.5:0.5:3.5. In Example 4, the cationic collector was tetradecylamine, the anionic collector was oxidized paraffin soap, and the mass concentration of hydrochloric acid was 38%. In Example 5, the first stirring reaction was carried out at 30°C for 20 minutes, the second stirring reaction was carried out at 30°C for 60 minutes, and the settling and ripening process was carried out at 25°C for 60 minutes.

[0092] The Al enrichment factor of Examples 2 to 5 was tested using the method described in Example 1.

[0093] The specific data is shown in Table 9.

[0094] Table 9

[0095] As shown in Table 9, the modified ammonium salt collectors prepared in Examples 2 to 5 of the present invention can all achieve selective enrichment of Al element in foam products, with Al enrichment factor of more than 3.79, which is much higher than 1.04 in Comparative Example 1 and 2.09 in Comparative Example 2.

[0096] The above are merely preferred embodiments of the present invention and do not limit the scope of the patent. Any equivalent structural or procedural transformations made based on the description and drawings of the present invention, or direct or indirect applications in other related technical fields, are similarly included within the scope of patent protection of the present invention.

Claims

1. A modified ammonium salt collector, characterized in that, The modified ammonium salt collector has the following general structural formula: RNH3 + · - OOC C 17 H 33 R is C 12~14 The alkyl group, wherein the modified ammonium salt collector is obtained by reacting a cationic collector, hydrochloric acid and an anionic collector.

2. The modified ammonium salt collector according to claim 1, characterized in that, The cationic collector reacts with the hydrochloric acid to obtain an intermediate, and the intermediate reacts with the anionic collector to obtain the modified ammonium salt collector.

3. The modified ammonium salt collector according to claim 1, characterized in that, The cationic collector includes at least one of dodecylamine, tetradecylamine, and isododecylamine.

4. The modified ammonium salt collector according to claim 1, characterized in that, The anionic collector includes at least one of sodium oleate, oxidized paraffin soap, and tal oil soap.

5. The modified ammonium salt collector according to any one of claims 1 to 4, characterized in that, The cationic collector comprises 3.5 to 4.5 parts by weight, the anionic collector comprises 0.5 to 1.5 parts by weight, and the hydrochloric acid comprises 3.5 to 4.5 parts by weight. And / or, the hydrochloric acid has a mass fraction of 36% to 38%.

6. The modified ammonium salt collector according to claim 5, characterized in that, The mass ratio of the cationic collector, the anionic collector, and the hydrochloric acid is 4:1:

4.

7. The modified ammonium salt collector according to claim 5, characterized in that, The modified ammonium salt collector is an oily paste.

8. A method for preparing a modified ammonium salt collector, characterized in that, The preparation method includes the following steps: Hydrochloric acid was added to the cationic collector, and the first stirring reaction yielded an intermediate. An anion collector was added to the intermediate, and a second stirring reaction was carried out to obtain the reaction product. The reaction product was allowed to stand and mature to obtain a modified ammonium salt collector.

9. The method for preparing the modified ammonium salt collector according to claim 8, characterized in that, The reaction temperature for the first stirring reaction is 20℃~30℃, and the reaction time is 10min~20min; And / or, the reaction temperature of the second stirring reaction is 20℃~30℃, and the reaction time is 30min~60min.

10. The application of the modified ammonium salt collector according to any one of claims 1 to 7 in an ore flotation process.

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