Bauxite flotation iron removal collector and preparation method and application thereof

Abstract

This application relates to a bauxite flotation iron removal collector, its preparation method, and its application. The collector's molecular structure incorporates both phosphonic acid groups and tertiary amine groups. During flotation, the phosphonate groups dissociate to form phosphonate ions, which then bond with Al atoms on the surface of gibbsite via their own phosphorus-oxygen double bonds. 3+ Formation of chelates enhances adsorption stability; simultaneously, it affects Al 3+ It exhibits excellent selectivity; the tertiary amine group gives the collector an isomerically charged distribution, blocking electrostatic attraction with negatively charged hematite and enhancing ion selectivity; the terminal carbon chain hydroxyl group of the tertiary amine group improves the collector's solubility and dispersibility at room temperature; this collector, by introducing phosphonic acid groups and tertiary amine groups into the carbonyl group, has a mild process and low industrialization cost. When applied to high-iron gibbsite bauxite, this collector can simultaneously achieve technical advantages such as high selectivity, low reagent consumption, resistance to low-temperature conditions, and excellent foam stability.

Description

Technical Field

[0001] This application relates to the field of mineral processing flotation reagents, and in particular to a bauxite flotation iron removal collector, its preparation method, and its application. Background Technology

[0002] The core technical challenge in developing high-speed bauxite resources (such as in Guinea) lies in the fact that gibbsite has similar surface physicochemical properties to hematite and goethite, resulting in poor selectivity of conventional collectors for the target minerals.

[0003] Currently, the collectors widely used in industry mainly include fatty acid derivatives (such as sodium oleate and oxidized paraffin soap) and hydroxamic acids; however, these two types of collectors have many technical shortcomings: firstly, they have limitations in their effect on the Ca in the system. 2+ Fe 3+ Firstly, due to their high ion sensitivity, they tend to cause non-selective collection of iron minerals, making it difficult to achieve efficient separation of aluminum-iron minerals. Secondly, their solubility and dispersibility are poor at room temperature, requiring heated flotation processes, which significantly increases production energy consumption. Thirdly, the actual dosage of reagents is generally high, significantly increasing the production cost of the flotation process. In addition, fatty acid collectors are prone to generating viscous foam, which not only interferes with the smooth operation of flotation but also hinders the subsequent concentrate transportation process.

[0004] While physical combinations of fatty acids and hydroxamic acid can optimize some of the properties of collectors, this approach does not address the fundamental molecular structure and therefore cannot overcome the inherent limitations of existing collectors, resulting in very limited performance improvements. Therefore, developing novel collectors with both excellent collecting ability and high selectivity from a molecular design perspective has become a critical technical challenge that urgently needs to be overcome in this field.

[0005] In view of this, it is necessary to design a bauxite flotation iron removal collector, its preparation method, and its application to solve the above problems. Summary of the Invention

[0006] This application provides a bauxite flotation iron removal collector, its preparation method, and its application, in order to solve the problem of poor selectivity of current collectors for aluminum and iron elements in high-iron bauxite.

[0007] In a first aspect, this application provides a bauxite flotation iron removal collector, said collector having the chemical structural formula shown in formula (I): (Ⅰ); In formula (I), R1 includes at least one substituted or unsubstituted phosphate group; R2 includes at least one substituted or unsubstituted tertiary amine group.

[0008] In some embodiments, the number of carbon atoms in R1 is 2 to 10; and / or, The number of carbon atoms in R2 is 2 to 5.

[0009] In some embodiments, the collector comprises any one or more of 3-[bis(2-hydroxyethyl)amino]-3-oxopropylphosphonic acid, 4-[bis(2-hydroxyethyl)amino]-4-oxobutylphosphonic acid, 5-[bis(2-hydroxyethyl)amino]-5-oxopentylphosphonic acid, 6-[bis(2-hydroxyethyl)amino]-6-oxohexylphosphonic acid, 3-[bis(3-hydroxypropyl)amino]-3-oxopropylphosphonic acid, 3-[bis(4-hydroxybutyl)amino]-3-oxopropylphosphonic acid, and 5-[bis(3-hydroxypropyl)amino]-5-oxopentylphosphonic acid.

[0010] Secondly, this application provides a method for preparing the above-mentioned bauxite flotation iron removal collector, comprising the following steps: Diethyl phosphite and ω-olefin ethyl carboxylate compounds were subjected to Michael addition reaction to obtain ethyl carboxylate phosphonate compounds; The ethyl carboxylate phosphonate compound was mixed with a diolamine compound and subjected to an aminolysis-amidation reaction to obtain a carbamoyl phosphonate compound; and The carbamoyl phosphonate compound is subjected to a hydrolysis reaction to obtain the collector.

[0011] In some embodiments, the Michael addition reaction includes: ; and / or, The reaction formula for the aminolysis-amidation reaction includes: ; and / or, The hydrolysis includes: mixing the carbamoyl phosphonate compound with an acid reagent; The acid reagent includes hydrochloric acid; the mass concentration of the hydrochloric acid is 5%~20%; The reaction formula for the hydrolysis reaction includes: .

[0012] In some embodiments, the ω-olefin carboxylic acid ethyl ester compound includes any one or more of ethyl acrylate, ethyl butyronate, ethyl pent-4-enoate, and ethyl hex-5-enoate; and / or, The diethanolamine compounds include any one or more of diethanolamine, bis(3-hydroxypropyl)amine, and bis(4-hydroxybutyl)amine.

[0013] Thirdly, this application provides an application of the above-mentioned bauxite flotation iron removal collector, wherein the collector is applied to bauxite flotation iron removal; The bauxite includes high-iron bauxite; By mass percentage, the Fe2O3 content in the high-iron bauxite is 25.39%~48.36%, and the Al2O3 content is 28.26%~45.56%.

[0014] Fourthly, this application provides a method for applying the above-mentioned iron removal collector in bauxite flotation, comprising the following steps: The pH of the bauxite slurry was adjusted to obtain a modified bauxite slurry. Inhibitors and collectors are added sequentially to the modified bauxite slurry, and flotation is performed to obtain de-ironized slurry.

[0015] In some embodiments, the pH value of the modified bauxite slurry is 4-10; and / or, The flotation temperature is 15℃~50℃; and / or, Particles with a size <0.074 mm account for 75.0% to 95.0% of the total mass of the bauxite.

[0016] In some embodiments, the amount of collector added is 200 g / t bauxite to 800 g / t bauxite; and / or, The amount of the inhibitor added is 20g / t bauxite to 100g / t bauxite.

[0017] The technical solutions provided in this application have the following advantages compared with the prior art: 1. The core highlight of the bauxite flotation iron removal collector provided in this application is the simultaneous introduction of phosphonic acid groups and tertiary amine groups into the collector, forming a functionally complementary dual-active-end structure. Specifically, the chemical structure of the collector... (R1 contains -PO(OH)2 group; R2 contains In the N(CH2CH2OH)2 group, the phosphonic acid group (-PO(OH)2) serves as the core complexing group of the collector, replacing the carboxyl group (-COOH) in traditional collectors; during flotation, the phosphonic acid group (-PO(OH)2) dissociates into phosphonate ions (-PO(O)2). - )2), the phosphonate enhances the mineral separation efficiency through a dual action; specifically: (1) the phosphonate can use its own phosphorus-oxygen double bond (P=O) to react with the Al on the surface of gibbsite (AlOOH). 3+ To form stable bidentate or multidentate chelates, constructing a more thermodynamically stable five- or six-membered ring structure, greatly enhancing the adsorption strength and adsorption stability of the collector on the surface of gibbsite; (2) Phosphonate on Al3+ It possesses excellent selective recognition capabilities. Its unique electronic configuration and spatial structure enable it to precisely distinguish the metal ion coordination environments on the surfaces of gibbsite, hematite, and goethite, thereby achieving selective inhibition of iron minerals at the molecular level and laying the foundation for subsequent efficient separation. The tertiary amine group (-N(CH2(CH2)) at the other end of the collector's chemical structure... X OH)2) then acts as a multifunctional regulating unit, optimizing the overall molecular performance through multiple mechanisms; mainly reflected in: (1) within the subsequently defined pH flotation range, the collector simultaneously carries negative charge (phosphonate ions formed by the ionization of phosphonic acid groups carry negative charge) and positive charge (tertiary amine groups formed by the protonation reaction of tertiary amine groups (-NH) + -) Carrying a positive charge), this amphoteric electrical distribution can effectively block the electrostatic attraction between the collector and the positively charged hematite surface, further enhancing the inhibition effect and separation selectivity of iron minerals. (2) The two carbon chain hydroxyl groups at the end of the tertiary amine group (-CH2(CH2)) X The presence of OH provides strong hydrophilicity, significantly improving the solubility and dispersibility of collector molecules at room temperature and preventing the decrease in efficiency caused by molecular aggregation. Furthermore, this hydrophilic structure can effectively regulate the physicochemical properties of the gas-liquid interface film, replacing the molecular arrangement of traditional fatty acid collectors that easily form viscous foams. This allows for the construction of a foam system with fluidity and stability adapted to flotation requirements, ensuring a highly efficient and smooth flotation process.

[0018] 2. The method for preparing the bauxite flotation iron removal collector provided in this application involves first subjecting diethyl phosphite and ω-olefin ethyl carboxylate compounds to a Michael addition reaction to obtain ethyl carboxylate-based phosphonates; then subjecting the ethyl carboxylate-based phosphonates to an aminolysis-amidation reaction with a diolamine compound to obtain carbamoyl phosphonates; finally, hydrolyzing the carbamoyl phosphonates; thus, phosphonic acid groups (-PO(OH)2) and tertiary amine groups (-N(CH2(CH2)) are directionally introduced into the carbonyl group. X The target flotation collector was successfully prepared by OH)2. This preparation method has the advantages of a clear and controllable reaction path, mild and easy-to-control process conditions, and strong equipment compatibility. It does not require harsh high temperature and high pressure or special catalysts, and can be directly adapted to existing chemical production lines for large-scale production, which can effectively reduce the cost and technical threshold of industrialization.

[0019] 3. Application of the bauxite flotation iron removal collector provided in this application embodiment: The collector prepared by the above method can achieve highly efficient and selective collection of iron impurities in bauxite due to the strong chelation effect of phosphonic acid groups with iron minerals and the affinity and synergistic adsorption characteristics of tertiary amine groups, significantly improving the grade of bauxite concentrate. Simultaneously, the raw materials are widely available, and the reaction byproducts are few and easily separated, combining economic feasibility and environmental friendliness, providing a practical and feasible technical solution for improving the quality and efficiency of bauxite flotation iron removal process. The bauxite flotation iron removal collector provided in this application embodiment is applied to bauxite flotation iron removal. Because the collector relies on the precise design of its molecular structure, using phosphonic acid groups as selective complexation centers to achieve highly efficient and specific collection of gibbsite; and using tertiary amine groups as multifunctional regulating units, leveraging their amphoteric properties and strong hydrophilicity to achieve molecular electrical regulation, stable dispersion in a room temperature system, and optimized regulation of flotation foam characteristics. When processing complex bauxite deposits such as the Guinean high-iron trihydrate bauxite, this method offers simultaneous advantages including high selectivity, low reagent consumption, resistance to low-temperature conditions, and excellent foam stability. Practical application has verified that the Fe2O3 content in the de-ironized slurry can be reduced to below 25%. Furthermore, the flotation foam possesses suitable viscosity and stability, ensuring continuous and efficient mineral processing operations. The collector provided in this application offers a novel and reliable technical solution to the challenges of efficient development and resource utilization of difficult-to-process high-iron bauxite resources, and possesses broad industrial application prospects. Attached Figure Description

[0020] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0021] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 A flowchart of a method for preparing an iron removal collector for bauxite flotation provided in this application is shown; Figure 2 This application provides a flotation process diagram for removing iron from bauxite using a "one-stage roughing-one-stage cleaning-one-stage scavenging" method. Figure 3 The present application provides a flotation process diagram for removing iron from bauxite using a "one roughing-two cleaning-one scavenging" method. Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0024] Various embodiments of this application may exist in the form of a range. It should be understood that the description in the form of a range is merely for convenience and brevity and should not be construed as a rigid limitation on the scope of this application. Therefore, it should be considered that the range description has specifically disclosed all possible sub-ranges and single numerical values ​​within that range. For example, it should be considered that the range description from 1 to 6 has specifically disclosed sub-ranges, such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., and single numbers within the range, such as 1, 2, 3, 4, 5, and 6, regardless of the range. In addition, whenever a numerical range is indicated in this application, it means including any referenced number (fraction or integer) within the indicated range. Unless otherwise specified, all raw materials, reagents, instruments, and equipment used in this application can be purchased commercially or prepared by existing methods. In this application, unless otherwise stated, directional terms such as "upper" and "lower" specifically refer to the drawing directions in the accompanying drawings. In addition, in this application, the terms "comprising," "including," etc., mean "including but not limited to." In this application, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, without necessarily requiring or implying any actual relationship or order between these entities or operations. In this application, "and / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A alone, A and B simultaneously, or B alone. A and B can be singular or plural. In this application, "at least one" means one or more, and "more than one" means two or more. "At least one," "at least one of the following," or similar expressions refer to any combination of these items, including any combination of single or plural items. For example, "at least one of a, b, or c," or "at least one of a, b, and c," can both represent: a, b, c, ab (i.e., a and b), ac, bc, or abc, where a, b, and c can each be single or multiple.

[0025] Unless otherwise specified, all raw materials, reagents, instruments and equipment used in this application can be purchased from the market or prepared by existing methods.

[0026] This application provides a bauxite flotation iron removal collector, the collector having the chemical structural formula shown in formula (I): (Ⅰ); In formula (I), R1 includes at least one substituted or unsubstituted phosphate group; R2 includes at least one substituted or unsubstituted tertiary amine group.

[0027] The bauxite flotation iron removal collector provided in this application is characterized by the simultaneous introduction of phosphonic acid groups and tertiary amine groups into the collector, forming a functionally complementary dual-active-terminal structure. Specifically, the chemical structure of the collector... (R1 contains a carbon chain and a -PO(OH)2 group; R2 contains a carbon chain, In the N(CH2CH2OH)2 group, the phosphonic acid group (-PO(OH)2) serves as the core complexing group of the collector, replacing the carboxyl group (-COOH) in traditional collectors; during flotation, the phosphonic acid group (-PO(OH)2) dissociates into phosphonate ions (-PO(O)2). - )2), the phosphonate group enhances the mineral separation efficiency through a dual action, specifically in the following ways: (1) the phosphonate group (-PO(OH)2) dissociates into phosphonate (-PO(O)2) - 2) Phosphonate can react with Al on the surface of gibbsite (AlOOH) via its own phosphorus-oxygen double bond (P=O). 3+ To form stable bidentate or multidentate chelates, constructing a more thermodynamically stable five- or six-membered ring structure, greatly enhancing the adsorption strength and adsorption stability of the collector on the surface of gibbsite; (2) Phosphonate on Al 3+ It possesses excellent selective recognition capabilities. Its unique electronic configuration and spatial structure enable it to precisely distinguish the metal ion coordination environments on the surfaces of gibbsite, hematite, and goethite, thereby achieving selective inhibition of iron minerals at the molecular level and laying the foundation for subsequent efficient separation. The tertiary amine group (-N(CH2(CH2)) at the other end of the collector's chemical structure... X OH)2) then acts as a multifunctional regulating unit, optimizing the overall molecular performance through multiple mechanisms; mainly reflected in: (1) within the subsequently defined pH flotation range, the collector simultaneously carries negative charge (phosphonate ions formed by the ionization of phosphonic acid groups carry negative charge) and positive charge (tertiary amine groups formed by the protonation reaction of tertiary amine groups (-NH) +-) Carrying a positive charge), this amphoteric electrical distribution can effectively block the electrostatic attraction between the collector and the positively charged hematite surface, further enhancing the inhibition effect and separation selectivity of iron minerals. (2) The two carbon chain hydroxyl groups at the end of the tertiary amine group (-CH2(CH2)) X The presence of OH provides strong hydrophilicity, significantly improving the solubility and dispersibility of collector molecules at room temperature and preventing the decrease in efficiency caused by molecular aggregation. Furthermore, this hydrophilic structure can effectively regulate the physicochemical properties of the gas-liquid interface film, replacing the molecular arrangement of traditional fatty acid collectors that easily form viscous foams. This allows for the construction of a foam system with fluidity and stability adapted to flotation requirements, ensuring a highly efficient and smooth flotation process.

[0028] As an optional implementation, in this embodiment, R1 has 2 to 10 carbon atoms; and R2 has 2 to 5 carbon atoms. It is worth noting that the carbon chains in R1 and / or R2 can be straight chains or branched chains.

[0029] Thus, by controlling the number of carbon atoms in substituents R1 and R2, the carbon chain length of the collector can be precisely controlled. This is because the carbon chain length has a significant regulatory effect on the hydrophobic and steric hindrance effects of the collector; an appropriate carbon chain length can enhance the interaction strength between the collector and the target mineral surface, thereby improving flotation efficiency.

[0030] If the carbon number of R1 is less than 2 or the carbon number of R2 is less than 2, the overall hydrophobicity of the collector molecule will be severely insufficient, significantly weakening the collector's ability to impart hydrophobicity to the surface of the target mineral, gibbsite. This results in insufficient driving force for the adhesion of mineral particles to bubbles, ultimately leading to a sharp decline in the recovery rate and yield of aluminum concentrate. Simultaneously, excessively short carbon chains are unlikely to form a stable adsorption film at the gas-liquid interface, easily leading to a barren and unstable foam layer, which is detrimental to the enrichment and recovery of concentrate. If the carbon number of R1 is greater than 10 or the carbon number of R2 is greater than 5, the hydrophobicity of the collector molecule will be too strong. Excessive hydrophobic association will cause the collector to non-selectively collect iron minerals such as hematite and goethite, and exacerbate the mechanical entrainment of fine-grained iron minerals, resulting in a significant deterioration in the selectivity of aluminum-iron separation, making it difficult to effectively control the iron content of the aluminum concentrate. Furthermore, excessively long carbon chains significantly reduce the solubility and dispersibility of molecules in the aqueous phase, often requiring heating for the collector to function effectively, thus negating the advantage of this application where flotation can be performed without high temperatures or even at room temperature. Moreover, excessively long carbon chains easily promote the formation of a dense and tough adsorption film at the gas-liquid interface, resulting in excessively high foam viscosity and stability, leading to a series of engineering operational problems such as difficulty in subsequent defoaming, low concentrate transportation and dewatering filtration efficiency. For example, the number of carbon atoms in R1 can be 2, 4, 5, 6, 7, 8, 9, 10, etc.; the number of carbon atoms in R2 can be 2, 4, 5, etc.

[0031] As an optional implementation, in this embodiment, the collector includes 3-[bis(2-hydroxyethyl)amino]-3-oxopropylphosphonic acid (structural formula: ), 4-[bis(2-hydroxyethyl)amino]-4-oxobutylphosphonic acid (structural formula: ), 5-[bis(2-hydroxyethyl)amino]-5-oxopentylphosphonic acid (structural formula: ), 6-[bis(2-hydroxyethyl)amino]-6-oxohexylphosphonic acid (structural formula: ), 3-[bis(3-hydroxypropyl)amino]-3-oxopropylphosphonic acid (structural formula: ), 3-[bis(4-hydroxybutyl)amino]-3-oxopropylphosphonic acid (structural formula: ), 5-[bis(3-hydroxypropyl)amino]-5-oxopentylphosphonic acid (structural formula: Any one or more of the following.

[0032] like Figure 1 As shown, based on a general inventive concept, this application provides a method for preparing the above-mentioned bauxite flotation iron removal collector, comprising the following steps: Step 1: Diethyl phosphite and ω-olefin ethyl carboxylate compounds undergo a Michael addition reaction to obtain ethyl carboxylate phosphonate compounds; Step 3: Mix the ethyl carboxylate phosphonate compound with a diolamine compound and carry out an aminolysis-amidation reaction to obtain carbamoyl phosphonate compound; Step 4: Hydrolyze the carbamoyl phosphonate compound to obtain the collector.

[0033] The method for preparing the bauxite flotation iron removal collector provided in this application involves first subjecting diethyl phosphite and ω-olefin ethyl carboxylate compounds to a Michael addition reaction to obtain ethyl carboxylate-based phosphonates; then subjecting the ethyl carboxylate-based phosphonates to an aminolysis-amidation reaction with a diolamine compound to obtain carbamoyl phosphonates; finally, hydrolyzing the carbamoyl phosphonates; thus, phosphonic acid groups (-PO(OH)2) and tertiary amine groups (-N(CH2(CH2)) are directionally introduced into the carbonyl group. X The target flotation collector was successfully prepared by OH)2. This preparation method has the advantages of a clear and controllable reaction path, mild and easy-to-control process conditions, and strong equipment compatibility. It does not require harsh high temperature and high pressure or special catalysts, and can be directly adapted to existing chemical production lines for large-scale production, effectively reducing the cost and technical threshold of industrialization.

[0034] As an optional implementation, in this embodiment of the application, the reaction formula for the Michael addition reaction includes: P(O)(OC2H5)2H + CH2=CH-C(O)O(CH2) X CH3→(C2H5O)2P(O)(CH2) X C(O)OC2H5 ( ).

[0035] The reaction formula for the aminolysis-amidation reaction includes: (C2H5O)2P(O)(CH2) X C(O)OC2H5+ HN((CH2) X OH)2→(C2H5O)2P(O)(CH2) X C(O)N((CH2) X OH)2 ( .

[0036] The hydrolysis includes mixing the carbamoyl phosphonate compound with an acid reagent.

[0037] The acid reagent includes hydrochloric acid; the mass concentration of the hydrochloric acid is 5%~20%; The reaction formula for the hydrolysis reaction includes: (C2H5O)2P(O)(CH2) X C(O)N((CH2) X OH)2+ H2O / H + →(HO)2P(O)(CH2) X C(O)N(CH2(CH2) X OH)2 ( ).

[0038] Thus, the hydrolysis process can hydrolyze the phosphonate group (-PO(OR)2) into the phosphonic acid group (-PO(OH)2).

[0039] As an optional implementation, in the embodiments of this application, the ω-olefin carboxylic acid ethyl ester compound includes any one or more of ethyl acrylate, ethyl butyronate, ethyl pent-4-enoate, and ethyl hex-5-enoate.

[0040] In the embodiments of this application, the diethanolamine compound includes any one or more of diethanolamine, bis(3-hydroxypropyl)amine, and bis(4-hydroxybutyl)amine.

[0041] Based on a general inventive concept, this application provides an application of the above-mentioned bauxite flotation iron removal collector, wherein the collector is applied to bauxite flotation iron removal; The bauxite includes high-iron bauxite.

[0042] By mass percentage, the Fe2O3 content in the high-iron bauxite is 25.39%~48.36%, and the Al2O3 content is 28.26%~45.56%.

[0043] The collector prepared using this method achieves highly efficient and selective collection of iron impurities in bauxite due to the strong chelating effect of phosphonic acid groups with iron minerals and the affinity and synergistic adsorption characteristics of tertiary amine groups, significantly improving the grade of bauxite concentrate. Simultaneously, the raw materials are widely available, and the reaction byproducts are few and easily separated, combining economic feasibility and environmental friendliness, providing a practical and feasible technical solution for improving the quality and efficiency of bauxite flotation iron removal processes. Furthermore, the application of the bauxite flotation iron removal collector provided in this application relies on the precise design of its molecular structure. The phosphonic acid group serves as a selective complexation center, achieving highly efficient and specific collection of gibbsite; the tertiary amine group acts as a multifunctional regulating unit, leveraging its amphoteric properties and strong hydrophilicity to achieve molecular electrical regulation, stable dispersion at room temperature, and optimized control of flotation foam characteristics. The aforementioned molecular-level structural design and group synergistic effects endow this collector with excellent comprehensive performance. When processing complex bauxite deposits such as the Guinean high-iron trihydrate bauxite, this collector offers several advantages, including high selectivity, low reagent consumption, resistance to low-temperature conditions, and excellent foam stability. Practical application has verified that the Fe2O3 content in the de-ironized slurry can be reduced to below 25%. Furthermore, the flotation foam exhibits suitable viscosity and stability, ensuring continuous and efficient mineral processing operations. The application of this collector provides a novel and reliable technical solution to the challenges of efficient development and resource utilization of difficult-to-process high-iron bauxite resources, and it possesses broad prospects for industrial application.

[0044] Based on a general inventive concept, this application provides a method for applying the above-mentioned iron removal collector in bauxite flotation, comprising the following steps: The bauxite and water are mixed to obtain a bauxite slurry; A pH adjuster is added to the bauxite slurry to adjust the pH, thereby obtaining a modified bauxite slurry. Inhibitors and collectors are added to the modified bauxite slurry, and flotation is performed to obtain de-ironized slurry.

[0045] The method for applying the iron removal collector in bauxite flotation provided in this application involves adjusting the pH of the bauxite and adding inhibitors and collectors for flotation. The Fe2O3 content in the resulting iron-removed ore pulp can be reduced to below 25%. This is mainly due to the collector used. Its specific function is as follows: The collector incorporates both phosphonic acid groups and tertiary amine groups, forming a dual-active-end structure with complementary functions. The phosphonic acid group (-PO(OH)2) at one end of the chemical structure acts as the core complexing group, replacing the carboxyl group in traditional collectors, thus enhancing separation efficiency through a dual effect: (1) In the flotation environment, the phosphonic acid group (-PO(OH)2) dissociates into phosphonate (-PO(O)2) groups. - )2), its unique electronic structure and spatial configuration can interact with the Al on the surface of gibbsite (AlOOH). 3+ Stable bidentate or multidentate chelates are formed, and thermodynamically more stable five- or six-membered ring structures are constructed. The stability constant of this structure is significantly higher than that of complexes formed by carboxyl groups, which greatly enhances the adsorption strength and adsorption stability of the collector on the surface of gibbsite. This also provides a structural basis for reducing the amount of collector used; (2) Phosphonate on Al 3+ It possesses excellent selective recognition capabilities, with the electron cloud distribution provided by the phosphorus-oxygen double bond and phosphonic acid oxygen atoms, and is similar to Al. 3+ The coordination field (mainly octahedral) of Fe has a better matching degree compared to Fe. 3+ This allows for the formation of stronger covalent bonds. This unique electronic configuration and atomic spatial structure enables the collector to precisely distinguish the metal ion coordination environments on the surfaces of gibbsite, hematite, and goethite, thus preferentially and firmly adsorbing onto the bauxite surface and minimizing non-selective collection of iron minerals. This is the primary mechanism for achieving efficient aluminum-iron separation. The tertiary amine group (-N(CH2(CH2)) at the other end of the chemical structure... X OH)2) then serves as a multifunctional regulating unit for process intensification and property, optimizing the overall molecular performance through multiple mechanisms; its contribution is mainly reflected in two aspects: (1) within the subsequently defined pH flotation range, the collector simultaneously carries negative charge (phosphonate ions formed by the ionization of phosphonic acid groups carry negative charge) and positive charge (tertiary amine groups formed by the protonation reaction of tertiary amine groups (-NH) + -) Carrying a positive charge), when the phosphonic acid end of the molecule is anchored to the surface of gibbsite through the above chelation mechanism, the positively charged tertiary amine at its end is exposed to the slurry. For hematite and goethite, which are usually positively charged on the surface, a significant electrostatic repulsion force will be generated. This repulsion force physically blocks the collector molecule from approaching and adhering to the iron mineral surface, thereby strengthening the inhibitory effect of the entire molecule on the iron mineral from another dimension and further improving the selectivity of the separation process. (2) The two carbon chain hydroxyl groups at the end of the tertiary amine group (-CH2(CH2)) XThe OH group is a strong hydrophilic group that greatly enhances the hydration capacity and water solubility of the collector molecules through hydrogen bonding. This fundamentally overcomes the technical difficulties of traditional fatty acid collectors, which suffer from poor dissolution and dispersion at room temperature due to their strong hydrophobicity and large intermolecular forces, requiring additional heating for effective flotation. Ultimately, this achieves highly efficient room-temperature flotation, significantly reducing the energy consumption of the flotation process. Furthermore, this strong hydrophilic group can effectively insert into and reconstruct the gas-liquid interface film. At the gas-liquid interface, it can separate fatty acid molecules that easily cause foam stickiness, disrupting the dense, high-viscosity interface film structure formed by the latter, and promoting the formation of a mixed adsorption film with a suitable hydrophilic-hydrophobic ratio and a relatively loose molecular arrangement. The viscosity and strength of this interface film are significantly reduced, giving the foam generated during flotation the characteristics of uniform size, moderate stability, and excellent flowability. This completely solves the foam stickiness problem caused by traditional collectors and effectively avoids the engineering obstacles caused by foam stickiness to concentrate transportation and subsequent dewatering processes. It is evident that by regulating the physicochemical properties of the gas-liquid interface membrane, replacing the molecular arrangement of traditional fatty acid collectors that easily form viscous foam, a foam system with fluidity and stability adapted to flotation requirements can be constructed, ensuring the efficient and smooth operation of the flotation process.

[0046] This collector, through precise molecular structure design, uses phosphonic acid groups as selective complexation centers to achieve highly efficient and specific collection of gibbsite. It utilizes tertiary amine groups as performance adjustment units, leveraging their amphoteric properties and strong hydrophilicity to achieve multifunctionality, including molecular electrochemical regulation, ensuring room-temperature dispersibility, and optimizing foam properties. This innovative molecular-level design enables the collector to simultaneously achieve high selectivity, low reagent dosage, low-temperature tolerance, and excellent foam performance when processing high-iron gibbsite-type bauxite, providing reliable technical support for the efficient development and resource utilization of complex high-iron bauxite resources.

[0047] As an optional implementation, in this embodiment, the pH value of the modified bauxite slurry is 4-10. Exemplarily, the pH value of the modified bauxite slurry can be selected from specific values ​​such as 4, 5, 6, 7, 8, 9, and 10. Preferably, the pH value of the modified bauxite slurry is 8.0-9.0.

[0048] Therefore, controlling the pH of the modified bauxite slurry to 4-10 is necessary because pH fundamentally affects the physicochemical properties of mineral surfaces, the form of collectors, and the interaction mechanism between the two. When the pH of the system is less than 4, the slurry is in a strongly acidic environment. On the one hand, this leads to a significant acid dissolution reaction of gibbsite (AlOOH), causing irreversible chemical loss of alumina components and directly reducing the final recovery rate of the target product. On the other hand, it inhibits the dissociation process of phosphonic acid groups (-PO(OH)2) in the amphoteric collector and causes excessive protonation of tertiary amine groups, causing the collector molecules to lose their ability to effectively bond with the active sites on the target mineral surface. Conversely, when the pH is greater than 10, the excessively alkaline conditions cause excessive hydroxylation reactions on the surfaces of iron minerals such as hematite and goethite, significantly increasing the electronegativity of the iron mineral surface and greatly weakening the electrostatic repulsion between the iron minerals and the collector molecules. This can even induce non-selective chemical adsorption of the collector on the surfaces of aluminum and iron minerals, ultimately resulting in the simultaneous collection of aluminum and iron minerals and a complete loss of separation effect.

[0049] Crucially, within the weakly alkaline pH range of 8.0–9.0, the collector exhibits its optimal electrical state—the phosphonic acid groups fully dissociate into negatively charged phosphonate ions, while the tertiary amine groups are moderately protonated and become positively charged. In this state, the collector molecules effectively target the Al atoms on the surface of gibbsite. 3+ The active sites exhibit the highest chelation selectivity and adsorption strength, while also generating the strongest electrostatic repulsion effect on the negatively charged iron mineral surface, thus constructing the optimal thermodynamic window for achieving highly selective separation of aluminum-iron minerals.

[0050] As an optional implementation, in this embodiment of the application, the flotation temperature is 15℃~50℃. For example, the flotation temperature can be a specific value such as 15℃, 18℃, 20℃, 23℃, 25℃, 28℃, 30℃, 33℃, 35℃, 38℃, 40℃, 43℃, 45℃, 48℃, or 50℃.

[0051] The setting of this temperature range can significantly improve the solubility and selectivity of the collector, thereby optimizing the flotation process efficiency and improving the economic feasibility of the process. The setting of the lower limit of 15℃ fully demonstrates the core advantage of the collector provided in this application compared to traditional fatty acid collectors—the introduction of strong hydrophilic groups such as hydroxyl groups in its molecular structure endows the collector with excellent room-temperature solubility and dispersion properties, achieving stable flotation without additional heating and significantly reducing process energy consumption. However, if the flotation temperature is below 15℃, the collector solubility will decrease significantly, requiring an increase in reagent dosage to ensure separation effect, and may also lead to poor flotation selectivity due to uneven reagent dispersion. If the temperature is above 50℃, it will destroy the stability of the collector's molecular structure, weaken its selective recognition ability for aluminum and iron minerals, and may also accelerate reagent decomposition, leading to a decline in flotation effect, additional temperature control energy consumption, and reduced process economy.

[0052] As an optional implementation, in this embodiment of the application, the amount of collector added is 200 g / t bauxite to 800 g / t bauxite. For example, the amount of collector added can be specific values ​​such as 200 g / t dry ore, 250 g / t dry ore, 300 g / t dry ore, 350 g / t dry ore, 400 g / t dry ore, 450 g / t dry ore, 500 g / t dry ore, 550 g / t dry ore, 600 g / t dry ore, 650 g / t dry ore, 700 g / t dry ore, 750 g / t dry ore, and 800 g / t dry ore.

[0053] Understandably, controlling the amount of collector added to 200g / t bauxite to 800g / t bauxite can ensure the efficient recovery of aluminum concentrate while maintaining a relatively high grade. This effectively removes iron-containing mineral impurities from the ore and ensures that the recovery efficiency of alumina in the concentrate is at a high level.

[0054] If the collector dosage is less than 200 g / t, the collector molecules cannot form a dense and complete monomolecular adsorption layer on the surface of gibbsite, making it difficult to impart sufficient hydrophobicity to the target mineral for effective flotation. This ultimately leads to a simultaneous decrease in both aluminum concentrate yield and alumina recovery rate. Conversely, if the collector dosage exceeds 800 g / t, the excessive collector will adsorb onto the surface of iron minerals through non-selective mechanisms such as physical adsorption, semi-micelle adsorption, and hydrophobic association, forcing the iron minerals to float along with the aluminum minerals. This severely impairs the separation selectivity of aluminum-iron minerals. At the same time, excessive reagents will cause a sharp increase in flotation foam viscosity and decreased fluidity, leading to operational problems such as foam entrainment of ore slime and difficulty in continuous and stable separation operations. It will also directly and significantly increase the cost of mineral processing reagents, reducing the economic feasibility of the process.

[0055] As an optional implementation, in this embodiment, the amount of inhibitor added is 20 g / t bauxite to 100 g / t bauxite. For example, the amount of inhibitor added can be specific values ​​such as 20 g / t bauxite, 30 g / t bauxite, 40 g / t bauxite, 50 g / t bauxite, 60 g / t bauxite, 70 g / t bauxite, 80 g / t bauxite, 90 g / t bauxite, or 100 g / t bauxite.

[0056] Understandably, in the bauxite flotation iron removal process, the core mechanism of inhibitors lies in shielding or modifying the active sites on the surface of iron-bearing minerals through adsorption or chemical reaction, weakening the interaction between iron-bearing minerals and flotation collectors, thereby preventing iron minerals from being enriched along with aluminum minerals during flotation. If the amount of inhibitor added is less than 20 g / t bauxite, it is insufficient to form a dense and complete monomolecular adsorption layer on the surface of iron minerals such as hematite and goethite. This not only fails to effectively shield the active adsorption sites on the surface of iron minerals but also makes it difficult to fully disperse the fine-grained slime in the pulp, thus exacerbating the non-selective adsorption of the collector on the surface of iron minerals, ultimately leading to the iron impurity content in the aluminum concentrate exceeding the required standards. Conversely, if the amount of inhibitor added exceeds 100 g / t of bauxite, the excessive inhibitor will diffuse to the surface of gibbsite and compete for adsorption, hindering the effective bonding between the collector and the active sites on the surface of gibbsite. This will suppress the floatability of gibbsite itself, resulting in a significant decline in the recovery rate of aluminum concentrate. At the same time, excessive inhibitor will significantly increase the viscosity of the slurry, destroy the stability and flowability of the flotation foam, and also increase reagent costs, reducing the economic feasibility of the process.

[0057] As an optional implementation, in the embodiments of this application, the inhibitor includes any one or more of sodium hexametaphosphate, water glass, carboxymethyl cellulose, starch, and dextrin.

[0058] As an optional implementation, in this embodiment of the application, the mass concentration of the bauxite slurry is 200~500 g / L. Exemplarily, the mass concentration of the bauxite slurry can be selected from specific values ​​such as 200 g / L, 250 g / L, 300 g / L, 350 g / L, 400 g / L, 450 g / L, and 500 g / L.

[0059] In the embodiments of this application, the acid-base regulator includes either Na2CO3 or hydrochloric acid.

[0060] As an optional implementation, in this embodiment of the application, particles with a size <0.074mm account for 75.0% to 95.0% of the total mass of the bauxite. For example, the percentage of particles smaller than 0.074mm in the bauxite can be selected from specific values ​​such as 75%, 76%, 77%, 78%, 79%, 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, and 95%.

[0061] Understandably, the limitation on the grinding fineness of bauxite is determined by a balance among three factors: the mineral dissemination characteristics of the ore, the required degree of liberation, and the negative effects of over-grinding. If the proportion of particles smaller than 0.074 mm in the grinding is less than 75.0%, gibbsite and iron-bearing minerals such as hematite and goethite will be difficult to achieve sufficient liberation. The large number of intergrowth particles in the system will significantly weaken the selective recognition of aluminum and iron minerals by collectors and depressants during flotation, ultimately leading to a significant decrease in aluminum-iron separation efficiency. Conversely, if the proportion of particles smaller than 0.074 mm in the grinding is higher than 95.0%, although it can improve the degree of mineral liberation to some extent, it will be accompanied by the formation of a large amount of secondary slime. These fine particles have a very large specific surface area, which can cause non-selective adsorption of collectors and inhibitors, resulting in a sharp increase in reagent consumption. At the same time, secondary slime can easily coat the surface of coarse minerals through the slime capping effect, which not only worsens the floatability of coarse minerals, but also significantly increases the viscosity of the pulp, destroys the stability of the flotation foam system, and thus has an adverse effect on the overall separation index.

[0062] As an optional implementation, in this embodiment of the application, the flotation method adopts as follows: Figure 2 The process is carried out using the method of "one coarse selection, one fine selection, and one sweep selection".

[0063] The present application is further illustrated below with reference to specific embodiments. Experimental methods in the following embodiments that do not specify specific conditions are generally determined according to national standards. If no corresponding national standard exists, then generally accepted international standards, conventional conditions, or conditions recommended by the manufacturer are followed.

[0064] Example 1 Example 1 provides a method for preparing an iron removal collector for bauxite flotation, comprising the following steps: Step 1: Provide diethyl phosphite, ethyl acrylate (ω-olefin carboxylic acid ethyl ester compound), and diethanolamine (diolamine compound); Step 2: Diethyl phosphite and ethyl acrylate are subjected to a Michael addition reaction to obtain diethyl(2-ethoxycarbonylethyl)phosphonate; Step 3: Mix diethyl(2-ethoxycarbonylethyl)phosphonate with diethanolamine and carry out an aminolysis-amidation reaction to generate diethyl3-[bis(2-hydroxyethyl)amino]-3-oxopropylphosphonate; Step 4: Mix diethyl 3-[bis(2-hydroxyethyl)amino]-3-oxopropylphosphonate with 10% hydrochloric acid and carry out hydrolysis reaction to obtain the collector (3-[bis(2-hydroxyethyl)amino]-3-oxopropylphosphonic acid).

[0065] The obtained collector has the following chemical structural formula: .

[0066] The above-mentioned collector is applied to the flotation of bauxite for iron removal; the bauxite includes high-iron bauxite; by mass percentage, the Al2O3 content in high-iron bauxite is 28.26% and the Fe2O3 content is 48.36%.

[0067] Example 1 also provides a method for iron removal by flotation of bauxite, comprising the following steps: Bauxite and water were mixed to obtain a bauxite slurry with a mass concentration of 200 g / L. Na₂CO₃ was added to the bauxite slurry to adjust the pH, resulting in a modified bauxite slurry with a pH of 9; particles with a size <0.074 mm accounted for 75.5% of the total mass of the bauxite. 20 g / t of inhibitor (sodium hexametaphosphate) and 200 g / t of collector (3-[bis(2-hydroxyethyl)amino]-3-oxopropylphosphonic acid) were added sequentially to the modified bauxite slurry, and flotation was carried out at a temperature of 15 °C to obtain the de-ironized slurry.

[0068] The flotation method adopted is as follows: Figure 2 The process is carried out using the method of "one coarse selection, one fine selection, and one sweep selection".

[0069] The yield of the de-ironized slurry, the Al2O3 recovery rate in the aluminum concentrate, the Al2O3 content in the aluminum concentrate, and the Fe2O3 content in the aluminum concentrate prepared by the above application method are shown in Table 1.

[0070] Example 2 Example 2 provides a method for preparing an iron removal collector for bauxite flotation, comprising the following steps: Step 1: Provide diethyl phosphite, ethyl butyrate (an ω-olefin carboxylic acid ethyl ester compound), and diethanolamine (a diolamine compound); Step 2: Diethyl phosphite and ethyl butyrate are subjected to a Michael addition reaction to obtain diethyl(3-ethoxycarbonylpropyl)phosphonate; Step 3: Diethyl(3-ethoxycarbonylpropyl)phosphonate is mixed with diethanolamine and subjected to an aminolysis-amidation reaction to generate diethyl3-[bis(2-hydroxyethyl)amino]-3-oxopentylphosphonate; Step 4: Diethyl 3-[bis(2-hydroxyethyl)amino]-3-oxopentylphosphonate is mixed with 5% hydrochloric acid and subjected to hydrolysis to obtain the collector (4-[bis(2-hydroxyethyl)amino]-4-oxobutylphosphonic acid). The obtained collector has the following chemical structural formula: .

[0071] The above-mentioned collector is applied to the flotation of bauxite for iron removal; the bauxite includes high-iron bauxite; by mass percentage, the Al2O3 content in high-iron bauxite is 39.35% and the Fe2O3 content is 32.21%.

[0072] Example 2 also provides a method for iron removal by flotation of bauxite, comprising the following steps: Bauxite and water were mixed to obtain a bauxite slurry with a mass concentration of 500 g / L. Na₂CO₃ was added to the bauxite slurry to adjust the pH, resulting in a modified bauxite slurry with a pH of 8; particles with a size <0.074 mm accounted for 85.32% of the total mass of the bauxite. 70 g / t of inhibitor (carboxymethyl cellulose) and 350 g / t of collector (4-[bis(2-hydroxyethyl)amino]-4-oxobutylphosphonic acid) were added sequentially to the modified bauxite slurry, and flotation was carried out at a temperature of 25°C to obtain the de-ironized slurry.

[0073] The flotation method adopted is as follows: Figure 2 The process is carried out using the method of "one coarse selection, one fine selection, and one sweep selection".

[0074] The yield of the de-ironized slurry, the Al2O3 recovery rate in the aluminum concentrate, the Al2O3 content in the aluminum concentrate, and the Fe2O3 content in the aluminum concentrate prepared by the above application method are shown in Table 1.

[0075] Example 3 Example 3 provides a method for preparing an iron removal collector for bauxite flotation, comprising the following steps: Step 1: Provide diethyl phosphite, ethyl acrylate (ω-olefin carboxylic acid ethyl ester compound), and bis(4-hydroxybutyl)amine (diolamine compound); Step 2: Diethyl phosphite and ethyl acrylate are subjected to a Michael addition reaction to obtain diethyl(2-ethoxycarbonylethyl)phosphonate; Step 3: Diethyl(2-ethoxycarbonylethyl)phosphonate is mixed with bis(4-hydroxybutyl)amine and subjected to an aminolysis-amidation reaction to generate diethyl4-[bis(4-hydroxybutyl)amino]-4-oxobutylphosphonate; Step 4: Diethyl 4-[bis(4-hydroxybutyl)amino]-4-oxobutylphosphonate is mixed with 15% hydrochloric acid and subjected to hydrolysis to obtain the collector (3-[bis(4-hydroxybutyl)amino]-3-oxopropylphosphonic acid). The obtained collector has the following chemical structural formula: .

[0076] The above-mentioned collector is applied to the flotation of bauxite for iron removal; the bauxite includes high-iron bauxite; by mass percentage, the Al2O3 content in high-iron bauxite is 38.75% and the Fe2O3 content is 31.78%.

[0077] Example 3 also provides a method for iron removal in bauxite flotation, comprising the following steps: Bauxite and water were mixed to obtain a bauxite slurry with a mass concentration of 350 g / L. The pH of the bauxite slurry was 6.9; particles with a size <0.074mm accounted for 90.03% of the total mass of the bauxite. 50 g / t of inhibitor (water glass) and 450 g / t of collector (3-[bis(4-hydroxybutyl)amino]-3-oxopropylphosphonic acid) were added sequentially to the modified bauxite slurry, and flotation was carried out at a temperature of 35°C to obtain de-ironized slurry.

[0078] The flotation method adopted is as follows: Figure 2 The process is carried out using the method of "one coarse selection, one fine selection, and one sweep selection".

[0079] The yield of the de-ironized slurry, the Al2O3 recovery rate in the aluminum concentrate, the Al2O3 content in the aluminum concentrate, and the Fe2O3 content in the aluminum concentrate prepared by the above application method are shown in Table 1.

[0080] Example 4 Example 4 provides a method for preparing an iron removal collector for bauxite flotation, comprising the following steps: Step 1: Provide diethyl phosphite, ethyl butyrate (ω-olefin carboxylic acid ethyl ester compound), and bis(4-hydroxybutyl)amine (diolamine compound); Step 2: Diethyl phosphite and ethyl butyrate are subjected to a Michael addition reaction to obtain diethyl(3-ethoxycarbonylpropyl)phosphonate; Step 3: Diethyl(3-ethoxycarbonylpropyl)phosphonate is mixed with bis(4-hydroxybutyl)amine and subjected to an aminolysis-amidation reaction to generate diethyl5-[bis(4-hydroxybutyl)carbamoyl]pentylphosphonate; Step 4: Diethyl 5-[bis(4-hydroxybutyl)carbamoyl]pentylphosphonate is mixed with 20% hydrochloric acid and subjected to hydrolysis to obtain the collector (4-[bis(4-hydroxybutyl)amino]-4-oxobutylphosphonic acid). The obtained collector has the following chemical structural formula: .

[0081] The above-mentioned collector is applied to the flotation of bauxite for iron removal; the bauxite includes high-iron bauxite; by mass percentage, the Al2O3 content in high-iron bauxite is 45.56% and the Fe2O3 content is 25.39%.

[0082] Example 4 also provides a method for iron removal in bauxite flotation, comprising the following steps: Bauxite and water were mixed to obtain a bauxite slurry with a mass concentration of 300 g / L. Hydrochloric acid was added to the bauxite slurry to adjust the pH, resulting in a modified bauxite slurry with a pH of 4; particles with a size <0.074 mm accounted for 94.14% of the total mass of the bauxite. 100 g / t of inhibitor (starch) and 600 g / t of collector (4-[bis(4-hydroxybutyl)amino]-4-oxobutylphosphonic acid) were added sequentially to the modified bauxite slurry, and flotation was carried out at a temperature of 50°C to obtain the de-ironized slurry.

[0083] The flotation method adopted is as follows: Figure 2 The process is carried out using the method of "one coarse selection, one fine selection, and one sweep selection".

[0084] The yield of the de-ironized slurry, the Al2O3 recovery rate in the aluminum concentrate, the Al2O3 content in the aluminum concentrate, and the Fe2O3 content in the aluminum concentrate prepared by the above application method are shown in Table 1.

[0085] Example 5 Example 5 provides a method for preparing an iron removal collector for bauxite flotation. The specific preparation method is the same as that in Example 2, and will not be repeated here.

[0086] The resulting collector was 4-[bis(2-hydroxyethyl)amino]-4-oxobutylphosphonic acid.

[0087] The above-mentioned collector was applied to the flotation of bauxite for iron removal; the bauxite was high-iron bauxite; by mass percentage, the Al2O3 content in the high-iron bauxite was 32.17% and the Fe2O3 content was 42.56%.

[0088] Example 5 also provides a method for iron removal in bauxite flotation, comprising the following steps: Bauxite and water were mixed to obtain a bauxite slurry with a mass concentration of 350 g / L. Na₂CO₃ was added to the bauxite slurry to adjust the pH, resulting in a modified bauxite slurry with a pH of 8; particles with a size <0.074 mm accounted for 86.11% of the total mass of the bauxite. 70 g / t of inhibitor (water glass) and 350 g / t of collector (4-[bis(2-hydroxyethyl)amino]-4-oxobutylphosphonic acid) were added sequentially to the modified bauxite slurry, and flotation was carried out at a temperature of 40 °C to obtain the de-ironized slurry.

[0089] The flotation method adopted is as follows: Figure 2 The process is carried out using the method of "one coarse selection, one fine selection, and one sweep selection".

[0090] The yield of the de-ironized slurry, the Al2O3 recovery rate in the aluminum concentrate, the Al2O3 content in the aluminum concentrate, and the Fe2O3 content in the aluminum concentrate prepared by the above application method are shown in Table 1.

[0091] Comparative Example 1 Comparative Example 1 provides a method for removing iron from bauxite by flotation, comprising the following steps: Bauxite and water were mixed to obtain a bauxite slurry with a mass concentration of 200 g / L; the bauxite included high-iron bauxite; by mass percentage, the high-iron bauxite contained 39.35% Al2O3 and 32.21% Fe2O3.

[0092] Na₂CO₃ was added to the bauxite slurry to adjust the pH, resulting in a modified bauxite slurry with a pH of 8. Particles with a size <0.074 mm accounted for 84.23% of the total bauxite mass. 70 g / t of inhibitor (carboxymethyl cellulose) and 800 g / t of collector (sodium oleate) were added sequentially to the modified bauxite slurry, and flotation was carried out at a temperature of 25°C to obtain de-ironized slurry.

[0093] The flotation method adopted is as follows: Figure 2 The process is carried out using the method of "one coarse selection, one fine selection, and one sweep selection".

[0094] The yield of the de-ironized slurry, the Al2O3 recovery rate in the aluminum concentrate, the Al2O3 content in the aluminum concentrate, and the Fe2O3 content in the aluminum concentrate prepared by the above application method are shown in Table 1.

[0095] Comparative Example 2 Comparative Example 2 provides a method for removing iron from bauxite by flotation, comprising the following steps: Bauxite and water were mixed to obtain a bauxite slurry with a mass concentration of 500 g / L; the bauxite was high-iron bauxite; by mass percentage, the bauxite contained 39.35% Al2O3 and 32.21% Fe2O3. Na₂CO₃ was added to the bauxite slurry to adjust the pH, resulting in a modified bauxite slurry with a pH of 8. Particles with a size <0.074 mm accounted for 86.12% of the total bauxite mass. 70 g / t of inhibitor (water glass) and 1000 g / t of collector (sulfonated oleic acid) were added sequentially to the modified bauxite slurry, and flotation was carried out at a temperature of 60°C to obtain the de-ironized slurry.

[0096] The flotation method adopted is as follows: Figure 2 The process is carried out using the method of "one coarse selection, one fine selection, and one sweep selection".

[0097] The yield of the de-ironized slurry, the Al2O3 recovery rate in the aluminum concentrate, the Al2O3 content in the aluminum concentrate, and the Fe2O3 content in the aluminum concentrate prepared by the above application method are shown in Table 1.

[0098] Comparative Example 3 Comparative Example 3 provides a method for preparing an iron removal collector for bauxite flotation, comprising the following steps: Sodium oleate and hydroxamic acid are mixed in a mass ratio of 1:1 to obtain a composite flotation collector.

[0099] Comparative Example 3 also provides a method for iron removal by flotation of bauxite, comprising the following steps: Bauxite and water were mixed to obtain a bauxite slurry with a mass concentration of 350 g / L; the bauxite included high-iron bauxite; by mass percentage, the bauxite contained 39.35% Al2O3 and 32.21% Fe2O3.

[0100] Na₂CO₃ was added to the bauxite slurry to adjust the pH, resulting in a modified bauxite slurry with a pH of 8; particles with a size <0.074 mm accounted for 83.25% of the total mass of the bauxite. 70 g / t of inhibitor (carboxymethyl cellulose) and 1000 g / t of composite flotation collector were added sequentially to the modified bauxite slurry, and flotation was carried out at a temperature of 50°C to obtain the de-ironized slurry.

[0101] The flotation method adopted is as follows: Figure 3 The process is carried out using the method of "one coarse selection, two fine selections, and one sweep selection".

[0102] The yield of the de-ironized slurry, the Al2O3 recovery rate in the aluminum concentrate, the Al2O3 content in the aluminum concentrate, and the Fe2O3 content in the aluminum concentrate prepared by the above application method are shown in Table 1.

[0103] Table 1. Results of aluminum concentrate obtained from each embodiment and comparative example.

[0104] Experimental results: Comparing Examples 1-5 and Comparative Examples 1-3, it can be seen that when the bauxite flotation iron removal collector prepared by the method provided in this application is applied to the bauxite flotation iron removal, the yield of the aluminum concentrate and the recovery rate of Al2O3 in the aluminum concentrate are higher than those of other collectors (the collectors used in Comparative Examples 1-3).

[0105] Examples 1-3 demonstrate that the collector provided in this application achieves excellent flotation results at low temperatures. Examples 1, 2, and 5 demonstrate that the collector provided in this application achieves excellent flotation results at lower dosages.

[0106] As can be seen, in the bauxite flotation iron removal collector provided in this application, the zwitterionic surfactant, possessing both anionic and cationic groups, generally exhibits superior environmental tolerance and mineral recognition selectivity. The excellent performance of the bauxite flotation iron removal collector provided in this application is the result of the combined effect of various parameters, none of which can be omitted.

[0107] There is still a significant gap in the application of such surfactants in the field of mineral flotation collectors, especially in the specific structure of amphoteric phosphonic acid compounds designed for the flotation needs of high-iron bauxite, for which no relevant technical reports have been found yet.

[0108] In summary, this invention provides a bauxite flotation iron removal collector, its preparation method, and its application. The core highlight of this design is the simultaneous introduction of phosphonic acid groups and tertiary amine groups into the collector, forming a functionally complementary dual-active-terminal structure. Specifically, the chemical structure of the collector... (R1 contains a carbon chain and a -PO(OH)2 group; R2 contains a carbon chain and a -N(CH2CH2OH)2 group) In this process, the phosphonic acid group (-PO(OH)2) serves as the core complexing group of the collector, replacing the carboxyl group (-COOH) in traditional collectors; during flotation, the phosphonic acid group (-PO(OH)2) dissociates into phosphonate ions (-PO(O)2) - )2), the phosphonate group enhances the mineral separation efficiency through a dual action; specifically: (1) the phosphonate group (-PO(OH)2) dissociates into phosphonate (-PO(O)2) - 2) Phosphonate can react with Al on the surface of gibbsite (AlOOH) via its own phosphorus-oxygen double bond (P=O). 3+ To form stable bidentate or multidentate chelates, constructing a more thermodynamically stable five- or six-membered ring structure, greatly enhancing the adsorption strength and adsorption stability of the collector on the surface of gibbsite; (2) Phosphonate on Al 3+ It possesses excellent selective recognition capabilities. Its unique electronic configuration and spatial structure enable it to precisely distinguish the metal ion coordination environments on the surfaces of gibbsite, hematite, and goethite, thereby achieving selective inhibition of iron minerals at the molecular level and laying the foundation for subsequent efficient separation. The tertiary amine group (-N(CH2(CH2)) at the other end of the collector's chemical structure... X OH)2) then acts as a multifunctional regulating unit, optimizing the overall molecular performance through multiple mechanisms; mainly reflected in: (1) within the subsequently defined pH flotation range, the collector simultaneously carries negative charge (phosphonate ions formed by the ionization of phosphonic acid groups carry negative charge) and positive charge (tertiary amine groups formed by the protonation reaction of tertiary amine groups (-NH) + -) Carrying a positive charge), this amphoteric electrical distribution can effectively block the electrostatic attraction between the collector and the positively charged hematite surface, further enhancing the inhibition effect and separation selectivity of iron minerals. (2) The two carbon chain hydroxyl groups at the end of the tertiary amine group (-CH2(CH2)) XThe presence of OH provides strong hydrophilicity, significantly improving the solubility and dispersibility of the collector molecules at room temperature and preventing the decrease in efficiency caused by molecular aggregation. Furthermore, this hydrophilic structure can effectively regulate the physicochemical properties of the gas-liquid interface film, replacing the molecular arrangement of traditional fatty acid collectors that easily form viscous foams. This allows for the construction of a foam system with fluidity and stability adapted to flotation requirements, ensuring a highly efficient and smooth flotation process. The provided method for preparing a bauxite flotation iron removal collector involves first performing a Michael addition reaction on diethyl phosphite and ω-olefin ethyl carboxylate compounds to obtain ethyl carboxylate-based phosphonates; then, performing an aminolysis-amidation reaction on the ethyl carboxylate-based phosphonates with diolamine compounds to obtain carbamoyl phosphonates; finally, the carbamoyl phosphonates are hydrolyzed. This process directionally introduces phosphonic acid groups (-PO(OH)2) and tertiary amine groups (-N(CH2(CH2)) into the carbonyl group. X The target flotation collector was successfully prepared by OH)2. This method has the advantages of a clear and controllable reaction path, mild and easily controllable process conditions, and strong equipment compatibility. It does not require harsh high temperature and high pressure or special catalysts and can be directly adapted to existing chemical production lines for large-scale production, effectively reducing the cost and technical threshold of industrialization. The collector prepared by the above method can achieve highly efficient and selective collection of iron impurities in bauxite due to the strong chelation effect of phosphonic acid groups and iron minerals, as well as the affinity and synergistic adsorption characteristics of tertiary amine groups, significantly improving the grade of bauxite concentrate. At the same time, the raw materials are widely available, and the reaction byproducts are few and easily separated, combining economic feasibility and environmental friendliness, providing a practical and feasible technical solution for improving the quality and efficiency of bauxite flotation iron removal process. The provided bauxite flotation iron removal collector is applied to the iron removal process in bauxite flotation. Due to its precise molecular structure design, the collector utilizes phosphonic acid groups as selective complexation centers to achieve highly efficient and specific collection of gibbsite. Tertiary amine groups serve as multifunctional regulating units, leveraging their amphoteric properties and strong hydrophilicity to achieve molecular electrical regulation, stable dispersion at room temperature, and optimized control of flotation foam characteristics. When processing complex bauxite such as Guinea high-iron gibbsite, it simultaneously achieves technical advantages such as high selectivity, low reagent consumption, resistance to low-temperature conditions, and excellent foam stability. Practical application verification shows that the Fe2O3 content in the bauxite concentrate can be reduced to below 25%; the reagent dosage is only 200g / t~800g / t, which is 1 / 3 to 1 / 2 of the traditional collector dosage, significantly reducing beneficiation costs; efficient flotation can be achieved within a room temperature range of 15℃~50℃ without the need for additional temperature control equipment; and the flotation foam possesses suitable viscosity and stability, ensuring continuous and efficient beneficiation operations. The application of the collector provided in this application offers a novel and reliable technical solution to the problem of efficient development and resource utilization of difficult-to-process high-iron bauxite resources, and has broad prospects for industrial application.

[0109] The above description is merely a specific embodiment of this application, enabling those skilled in the art to understand or implement this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed in this application.

Claims

1. A bauxite flotation iron removal collector, characterized in that, The collector has the chemical structural formula shown in formula (Ⅰ): (Ⅰ)； In formula (I), R1 includes at least one substituted or unsubstituted phosphate group; R2 includes at least one substituted or unsubstituted tertiary amine group.

2. The bauxite flotation iron removal collector according to claim 1, characterized in that, The number of carbon atoms in R1 is 2 to 10; and / or, The number of carbon atoms in R2 is 2 to 5.

3. The bauxite flotation iron removal collector according to claim 2, characterized in that, The collector comprises any one or more of 3-[bis(2-hydroxyethyl)amino]-3-oxopropylphosphonic acid, 4-[bis(2-hydroxyethyl)amino]-4-oxobutylphosphonic acid, 5-[bis(2-hydroxyethyl)amino]-5-oxopentylphosphonic acid, 6-[bis(2-hydroxyethyl)amino]-6-oxohexylphosphonic acid, 3-[bis(3-hydroxypropyl)amino]-3-oxopropylphosphonic acid, 3-[bis(4-hydroxybutyl)amino]-3-oxopropylphosphonic acid, and 5-[bis(3-hydroxypropyl)amino]-5-oxopentylphosphonic acid.

4. A method for preparing a bauxite flotation iron removal collector as described in any one of claims 1 to 3, characterized in that, Includes the following steps: Diethyl phosphite and ω-olefin ethyl carboxylate compounds were subjected to Michael addition reaction to obtain ethyl carboxylate phosphonate compounds; The ethyl carboxylate phosphonate compound was mixed with a diolamine compound and subjected to an aminolysis-amidation reaction to obtain a carbamoyl phosphonate compound; and The carbamoyl phosphonate compound is subjected to a hydrolysis reaction to obtain the collector.

5. The method for preparing the bauxite flotation iron removal collector according to claim 4, characterized in that, The reaction formula for the Michael addition reaction includes: ; and / or, The reaction formula for the aminolysis-amidation reaction includes: ; and / or, The hydrolysis includes: mixing the carbamoyl phosphonate compound with an acid reagent; The acid reagent includes hydrochloric acid; the mass concentration of the hydrochloric acid is 5%~20%; The reaction formula for the hydrolysis reaction includes: 。 6. The method for preparing the bauxite flotation iron removal collector according to claim 5, characterized in that, The ω-olefin carboxylic acid ethyl ester compounds include any one or more of ethyl acrylate, ethyl butyronate, ethyl pent-4-enoate, and ethyl hex-5-enoate; and / or, The diethanolamine compounds include any one or more of diethanolamine, bis(3-hydroxypropyl)amine, and bis(4-hydroxybutyl)amine.

7. The application of a collector as described in any one of claims 1 to 3, characterized in that, The collector is used for iron removal in bauxite flotation. The bauxite includes high-iron bauxite; By mass percentage, the Fe2O3 content in the high-iron bauxite is 25.39%~48.36%, and the Al2O3 content is 28.26%~45.56%.

8. A method for the application as described in claim 7, characterized in that, Includes the following steps: The pH of the bauxite slurry was adjusted to obtain a modified bauxite slurry. Inhibitors and collectors are added to the modified bauxite slurry, and flotation is performed to obtain de-ironized slurry.

9. The method of application according to claim 8, characterized in that, The modified bauxite slurry has a pH value of 4-10; and / or, The flotation temperature is 15℃~50℃; and / or, Particles with a size <0.074 mm account for 75.0% to 95.0% of the total mass of the bauxite.

10. The method of application according to claim 9, characterized in that, The amount of the collector added is 200 g / t bauxite to 800 g / t bauxite; and / or, The amount of the inhibitor added is 20g / t bauxite to 100g / t bauxite.

Images