A composite flocculant for hydrometallurgy based on phosphonic group and nano synergism, and a preparation method and application thereof

Abstract

This application provides a composite flocculant for hydrometallurgical processing based on phosphonic acid groups and nano-enhancing agents, its preparation method, and its application, relating to the field of hydrometallurgical technology. Calculated based on 100% of the total raw material mass of the composite flocculant, it includes: 70-90% heat-resistant, salt-resistant, and hydrolysis-resistant copolymer; 5-25% inorganic nano-core-shell synergist; and 3-8% buffer dispersant. The heat-resistant, salt-resistant, and hydrolysis-resistant copolymer is a three-dimensional network polymer obtained by free radical copolymerization of acrylamide, 2-acrylamido-2-methylpropanesulfonic acid, N-vinylpyrrolidone, and phosphonic acid-containing functional monomers. The inorganic nano-core-shell synergist has a core-shell structure, consisting of an outer shell and a core with an encapsulated design. The surface of the core is grafted with organophosphonate esters via chemical bonds to form the core-shell structure. This composite flocculant exhibits superior performance; it solves the problems of conventional flocculants requiring large dosages, having low flocculation efficiency, and being prone to degradation and failure in high-temperature, high-salt, and strong-acid environments.

Description

Technical Field

[0001] This application relates to the field of hydrometallurgical technology, and in particular to a composite flocculant for hydrometallurgical processing based on phosphonic acid groups and nano-enhancing, its preparation method and application. Background Technology

[0002] Hydrometallurgical processes, such as high-pressure acid leaching (HPAL) of lateritic nickel ore, acid leaching of cobalt ore, and leaching of manganese and zinc ore, often produce slurries with high temperatures (up to 85-95℃), high acidity (pH 1.5-3.0), and high ionic strength (Al³⁺). + Fe³ + The extreme characteristics of high concentrations (often ranging from several grams per liter to tens of grams per liter) pose a significant challenge to subsequent solid-liquid separation processes. Taking the most representative laterite nickel ore HPAL process as an example, the high concentration of Al in its slurry... 3+ Fe 3+ Polyvalent metal ions easily form "ion bridges" between polymer chains, leading to flocculant gelation or precipitation and eventual failure. Simultaneously, polyvalent metal ions compete with target particles for adsorption sites on the flocculant's active sites, significantly reducing flocculation efficiency. Even with the addition of temperature- and salt-resistant monomers such as 2-acrylamido-2-methylpropanesulfonic acid and N-vinylpyrrolidone, the issues of polymer solubility and spreadability can only be addressed to a certain extent. These problems remain unresolved in the extreme conditions of mineral slurry environments, where reduced flocculation leads to slow settling velocity, high supernatant turbidity, and low underflow concentration, severely hindering production efficiency.

[0003] Therefore, developing a composite flocculant that can actively capture and utilize interfering ions in slurry while maintaining the effective conformation and bridging ability of polymer chains under extreme conditions of high temperature, high acidity, and high salinity has become an inevitable technical direction for breaking through the bottleneck of solid-liquid separation in hydrometallurgical processes. Summary of the Invention

[0004] The purpose of this application is to provide a composite flocculant for hydrometallurgical processing based on phosphonic acid groups and nano-enhancing, so as to solve the above-mentioned problems.

[0005] To achieve the above objectives, this application adopts the following technical solution: This application provides a composite flocculant for hydrometallurgical processing based on phosphonic acid groups and nano-enhancing agents. The composite flocculant comprises, based on 100% of the total raw material mass, 70-90% of a temperature-resistant, salt-resistant, and hydrolysis-resistant copolymer, 5-25% of an inorganic nano-core-shell synergist, and 3-8% of a buffer dispersant. The temperature-resistant, salt-resistant, and hydrolysis-resistant copolymer is a three-dimensional network polymer obtained by free radical copolymerization of acrylamide, 2-acrylamido-2-methylpropanesulfonic acid, N-vinylpyrrolidone, and phosphonic acid functional monomers. The inorganic nano-core-shell synergist includes a core and a shell covering the core; the surface of the core is formed by chemically grafting organophosphonate compounds to form a core-shell structure.

[0006] Optionally, the viscosity-average molecular weight of the three-dimensional network polymer is 3 million to 8 million.

[0007] Optionally, the phosphonic acid-containing functional monomer includes at least one of vinylphosphonic acid, 2-acrylamido-2-methylpropionic acid, and N-(2-hydroxyethyl)vinylphosphonic acid.

[0008] Optionally, based on the total mass of the raw materials of the three-dimensional network polymer being 100%, the amount of the phosphonic acid-containing functional monomer added is 5-15%.

[0009] Optionally, the raw material of the core includes at least one of nano-silica, nano-titanium dioxide, and nano-zirconia.

[0010] Optionally, the organophosphonate compound includes 2-carboxyethylphenylphosphonic acid.

[0011] Optionally, the buffer dispersant includes a compound of sodium citrate and polyethylene glycol.

[0012] Optionally, the mass ratio of sodium citrate to polyethylene glycol is 1-3:1.

[0013] This application also provides a method for preparing a composite flocculant for hydrometallurgical processing based on phosphonic acid groups and nano-enhancing agents, comprising: Preparation of inorganic core-shell synergists: After amination of nanoparticles with an aminosilane coupling agent, they are condensed with an organophosphonate compound in the presence of a catalyst to obtain core-shell particles with phosphonates grafted onto their surface by chemical bonds, thus obtaining inorganic core-shell synergists. Acrylamide, 2-acrylamido-2-methylpropanesulfonic acid, N-vinylpyrrolidone and phosphonic acid-containing functional monomers were dissolved in deionized water, and N,N'-methylenebisacrylamide was added. After adjusting the pH value, a copolymer precursor solution was obtained. The inorganic nano-core-shell synergist was mixed with the copolymer precursor liquid, dispersed, and then mixed with an initiator to carry out an initiation polymerization reaction to obtain an organic-inorganic hybrid hydrogel. The organic-inorganic hybrid hydrogel was mixed and homogenized with sodium citrate and polyethylene glycol, and then dried to obtain the composite flocculant for hydrometallurgical based on phosphonic acid groups and nano-enhanced properties.

[0014] Optionally, the amount of N,N'-methylenebisacrylamide added is 0.05-0.15% of the total mass of the acrylamide, the 2-acrylamido-2-methylpropanesulfonic acid, the N-vinylpyrrolidone, and the phosphonic acid-containing functional monomer.

[0015] Optionally, the pH value can be adjusted to 6-7.

[0016] Optionally, the initiator comprises an ammonium persulfate / sodium bisulfite redox system; the amount of the initiator added is 0.1-0.5% of the total mass of the acrylamide, the 2-acrylamido-2-methylpropanesulfonic acid, the N-vinylpyrrolidone and the phosphonic acid-containing functional monomer.

[0017] Optionally, the reaction temperature for initiating the polymerization reaction is 25-30°C, and the reaction time is 4-6 hours.

[0018] This application also provides an application of a composite flocculant based on phosphonic acid groups and nano-enhancing in hydrometallurgical processes, wherein the composite flocculant is used in processes containing high concentrations of Al. 3+ and / or Fe 3+ Solid-liquid separation of ore slurry in wet smelting.

[0019] Compared with the prior art, the beneficial effects of this application include: This application provides a composite flocculant for hydrometallurgical processing based on phosphonic acid groups and nano-enhancing. The flocculant exhibits stable structure and superior performance in extreme slurry environments during hydrometallurgical processing. It solves the problems of conventional temperature- and salt-resistant flocculants, which suffer from high dosage, low flocculation efficiency, and easy degradation and failure in high-temperature, high-salt, and strong-acid environments. This application innovatively introduces a functional monomer containing phosphonic acid groups, whose phosphonic acid groups enhance the performance of Al... 3+ Fe 3+ High-valence metal ions possess extremely high specific complexing ability, preferentially binding to these interfering ions before amide groups and other groups in the copolymer to form stable water-soluble complexes. This design is the key mechanism for turning harm into benefit. On the one hand, it effectively "removes" free high-valence metal interfering ions from the slurry; on the other hand, these complexed ions themselves can act as dynamic "ionic cross-linking points," constructing a more robust ionic cross-linking network between polymer molecular chains, thereby significantly enhancing the strength and toughness of the floc skeleton.

[0020] The preparation method provided in this application employs an "in-situ composite and polymerization" process, enabling the functional copolymer and the nano-synergist to form a chemically and physically interpenetrating hybrid network structure during polymerization. This structure is not a simple mixture, but rather achieves synergy at the molecular scale. Its temperature resistance (derived from the rigid rings and cross-linked network of NVP), salt resistance (derived from the strong hydration effect of AMPS sulfonic acid groups), and resistance to ionic interference (derived from the synergistic complexation of phosphonic acid groups and synergists) produce a synergistic effect of "1+1>2". Attached Figure Description

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

[0022] Figure 1 A schematic diagram of the process flow for preparing the composite flocculant for hydrometallurgical processing based on phosphonic acid groups and nano-enhancing, as provided in Example 1. Figure 2 This is a comparison chart of the sedimentation curves of the product in Example 1 and the comparative product in a high-temperature slurry at 90°C. Detailed Implementation

[0023] As used in this article: "Prepared from" is synonymous with "comprising". The terms "comprising", "including", "having", "containing", or any other variations thereof as used herein are intended to cover non-exclusive inclusion. For example, a composition, step, method, article, or apparatus that includes the listed elements is not necessarily limited to those elements, but may include other elements not expressly listed or elements inherent to such composition, step, method, article, or apparatus.

[0024] The conjunction "composed of..." excludes any unspecified elements, steps, or components. If used in a claim, this phrase makes the claim closed, excluding materials other than those described, except for associated conventional impurities. When the phrase "composed of..." appears in a clause of the body of a claim rather than immediately following it, it limits only the elements described in that clause; other elements are not excluded from the claim as a whole.

[0025] When a quantity, concentration, or other value or parameter is expressed as a range, a preferred range, or a range defined by a series of upper and lower preferred values, this should be understood as specifically disclosing all ranges formed by any pair of any upper or preferred value with any lower or preferred value, regardless of whether the range is disclosed individually. For example, when the range “1–5” is disclosed, the described range should be interpreted as including ranges “1–4”, “1–3”, “1–2”, “1–2 and 4–5”, “1–3 and 5”, etc. When numerical ranges are described herein, unless otherwise stated, the range is intended to include its endpoints and all integers and fractions within that range.

[0026] In these embodiments, unless otherwise specified, the portions and percentages are all by weight.

[0027] "Parts by mass" refers to the basic unit of measurement that expresses the mass ratio of multiple components. One part can represent any unit mass, such as 1g or 2.689g. If we say that component A has "a" parts by mass and component B has "b" parts by mass, it means the ratio of the mass of component A to the mass of component B is a:b. Alternatively, it can mean that the mass of component A is aK and the mass of component B is bK (where K is any number representing a multiplier). It is important to understand that, unlike parts by mass, the sum of the mass parts of all components is not limited to 100 parts.

[0028] "And / or" is used to indicate that one or both of the described situations may occur, for example, A and / or B includes (A and B) and (A or B).

[0029] To better explain the technical solution provided in this application, the technical solution provided in this application will be described in general before the specific implementation.

[0030] In a first aspect, this application provides a composite flocculant for hydrometallurgical processing based on phosphonic acid groups and nano-enhancing agents. The composite flocculant comprises, based on 100% of the total raw material mass, 70-90% of a temperature-resistant, salt-resistant, and hydrolysis-resistant copolymer, 5-25% of an inorganic nano-core-shell synergist, and 3-8% of a buffer dispersant. The temperature-resistant, salt-resistant, and hydrolysis-resistant copolymer is a three-dimensional network polymer obtained by free radical copolymerization of acrylamide, 2-acrylamido-2-methylpropanesulfonic acid, N-vinylpyrrolidone, and phosphonic acid functional monomers. The inorganic nano-core-shell synergist includes a core and a shell covering the core; the surface of the core is formed by chemically grafting organophosphonate compounds to form a core-shell structure.

[0031] Optionally, based on the total mass of the raw materials of the composite flocculant as 100%, the amount of the temperature-resistant, salt-resistant, and hydrolysis-resistant copolymer can be 70%, 75%, 80%, 85%, 90%, or any value between 70% and 90%; the amount of the inorganic nano-core-shell synergist can be 5%, 10%, 15%, 20%, 25%, or any value between 5% and 25%; and the amount of the buffer dispersant can be 3%, 4%, 5%, 6%, 7%, 8%, or any value between 3% and 8%.

[0032] It is understandable that the innovative microstructure of the composite flocculant provided in this application greatly improves the flocculation efficiency. Composite core-shell particles with nano-silica (SiO2), titanium dioxide (TiO2), or zirconium oxide (ZrO2) as the core and surface grafted with organophosphonates (such as 2-carboxyethylphenylphosphonic acid) serve as synergists, achieving three functions from a microstructure perspective: (1) the rigid nano-core provides physical support, preventing the flocs from being destroyed under high temperature and high shear; (2) the densely packed phosphonate groups on the surface can generate a synergistic chelation effect with the phosphonic acid groups in the copolymer, efficiently "capturing" Al in local high ion concentration regions. 3+ / Fe 3+ (3) Its high specific surface area provides additional particle adsorption sites, which enhances the bridging and trapping effect.

[0033] In one optional embodiment, the viscosity-average molecular weight of the three-dimensional network polymer is 3 million to 8 million.

[0034] Optionally, the viscosity-average molecular weight of the three-dimensional network copolymer can be 3 million, 4 million, 5 million, 6 million, 7 million, or 8 million, or any value between 3 million and 8 million.

[0035] In an optional embodiment, the phosphonic acid-containing functional monomer includes at least one of vinylphosphonic acid, 2-acrylamido-2-methylpropionic acid, and N-(2-hydroxyethyl)vinylphosphonic acid.

[0036] In one optional embodiment, the amount of the phosphonic acid-containing functional monomer added is 5-15%, calculated based on the total mass of the raw materials of the three-dimensional network polymer as 100%.

[0037] Optionally, based on the total mass of the raw materials of the three-dimensional network copolymer being 100%, the amount of phosphonic acid functional monomers added can be 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, or any value between 5% and 15%.

[0038] In one optional embodiment, the raw material of the core includes at least one of nano-silica, nano-titanium dioxide, and nano-zirconia.

[0039] In an optional embodiment, the organophosphonate compound includes 2-carboxyethylphenylphosphonic acid.

[0040] In an optional embodiment, the buffer dispersant comprises a compound of sodium citrate and polyethylene glycol.

[0041] In one optional embodiment, the mass ratio of sodium citrate to polyethylene glycol is 1-3:1.

[0042] Optionally, the mass ratio of sodium citrate to polyethylene glycol can be 1:1, 2:1, 3:1, or any value between 1 and 3:1.

[0043] Secondly, this application also provides a method for preparing a composite flocculant for hydrometallurgical processing based on phosphonic acid groups and nano-enhancing agents, comprising: Preparation of inorganic core-shell synergists: After amination of nanoparticles with an aminosilane coupling agent, they are condensed with an organophosphonate compound in the presence of a catalyst to obtain core-shell particles with phosphonates grafted onto their surface by chemical bonds, thus obtaining inorganic core-shell synergists. Acrylamide, 2-acrylamido-2-methylpropanesulfonic acid, N-vinylpyrrolidone and phosphonic acid-containing functional monomers were dissolved in deionized water, and N,N'-methylenebisacrylamide was added. After adjusting the pH value, a copolymer precursor solution was obtained. The inorganic nano-core-shell synergist was mixed with the copolymer precursor liquid, dispersed, and then mixed with an initiator to carry out an initiation polymerization reaction to obtain an organic-inorganic hybrid hydrogel. The organic-inorganic hybrid hydrogel was mixed and homogenized with sodium citrate and polyethylene glycol, and then dried to obtain the composite flocculant for hydrometallurgical based on phosphonic acid groups and nano-enhanced properties.

[0044] In an optional embodiment, the amount of N,N'-methylenebisacrylamide added is 0.05-0.15% of the total mass of the acrylamide, the 2-acrylamido-2-methylpropanesulfonic acid, the N-vinylpyrrolidone, and the phosphonic acid-containing functional monomer.

[0045] Optionally, the amount of crosslinking agent N,N'-methylenebisacrylamide added can be 0.05%, 0.1%, 0.15% of the total mass of acrylamide, 2-acrylamido-2-methylpropanesulfonic acid, N-vinylpyrrolidone and phosphonic acid-containing functional monomers, or any value between 0.05% and 0.15%.

[0046] In one alternative implementation, the pH value is adjusted to 6-7.

[0047] Optionally, the pH value can be adjusted to 6, 6.1, 6.2, 6.3, 6.4, 6.5, 6.6, 6.7, 6.8, 6.9, 7, or any value between 6 and 7.

[0048] In an optional embodiment, the initiator comprises an ammonium persulfate / sodium bisulfite redox system; the amount of the initiator added is 0.1-0.5% of the total mass of the acrylamide, the 2-acrylamido-2-methylpropanesulfonic acid, the N-vinylpyrrolidone, and the phosphonic acid-containing functional monomer.

[0049] Optionally, the amount of initiator added can be 0.1%, 0.2%, 0.3%, 0.4%, or 0.5% of the total mass of acrylamide, 2-acrylamido-2-methylpropanesulfonic acid, N-vinylpyrrolidone, and phosphonic acid-containing functional monomers, or any value between 0.1% and 0.5%.

[0050] In one optional embodiment, the reaction temperature for initiating the polymerization reaction is 25-30°C, and the reaction time is 4-6 hours.

[0051] Optionally, the reaction temperature for initiating the polymerization reaction can be 25℃, 26℃, 27℃, 28℃, 29℃, 30℃, or any value between 25℃ and 30℃; the reaction time can be 4 hours, 5 hours, 6 hours, or any value between 4 and 6 hours.

[0052] Thirdly, this application also provides an application of a composite flocculant based on phosphonic acid groups and nano-enhancing in hydrometallurgical processes, wherein the composite flocculant is used in applications containing high concentrations of Al. 3+ and / or Fe 3+ Solid-liquid separation of ore slurry in wet smelting.

[0053] Specifically, the initial solids content and temperature of the wet leaching slurry to be treated are determined. The slurry is kept stirred to prevent particle settling. Under stirring conditions, the prepared flocculant working solution is slowly added to the slurry. After adding the flocculant, stirring continues to ensure thorough mixing of the flocculant and the slurry. This causes the fine particles in the slurry to rapidly aggregate into large, dense flocs. After agglomeration, stirring is stopped, allowing the slurry to enter the settling stage. The change in the settling interface height over time is recorded, and the initial settling velocity is calculated. After settling stabilizes, a clear interface is formed between the supernatant and the underflow slurry.

[0054] Compared to traditional flocculants, this method employs an "in-situ composite and polymerization" process, enabling the functional copolymer and nano-synergist to form a chemically and physically interpenetrating hybrid network structure during polymerization. This structure is not a simple mixture but rather achieves molecular-scale synergy. Simultaneously, the rigid nano-core provides physical support, preventing the flocs from being destroyed under high temperature and high shear, and the densely packed phosphonate groups on the surface can generate a synergistic chelation effect with the phosphonic acid groups in the copolymer, efficiently "capturing" Al in localized high-ion-concentration regions. 3+ / Fe 3+ It contains polyvalent ions; in addition, the high specific surface area provides additional adsorption sites for particles, enhancing bridging and trapping effects.

[0055] The implementation schemes of this application will be described in detail below with reference to specific embodiments. However, those skilled in the art will understand that the following embodiments are only for illustrating this application and should not be regarded as limiting the scope of this application. Unless otherwise specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall apply. Reagents or instruments used without specified manufacturers are all conventional products that can be purchased commercially.

[0056] Example 1 This embodiment provides a composite flocculant for hydrometallurgical processes based on phosphonic acid groups and nano-enhanced properties: The total mass of the raw materials for the composite flocculant is calculated as 100%, including: 153g of temperature-resistant, salt-resistant, and hydrolysis-resistant copolymer, 30g of inorganic nano-core-shell synergist, 5g of sodium citrate, and 5g of PEG-400.

[0057] The temperature-resistant, salt-resistant, and hydrolysis-resistant copolymer is a three-dimensional network polymer obtained by free radical copolymerization of acrylamide (AM, purchased from Shanghai Aladdin Biochemical Technology Co., Ltd., 100g), 2-acrylamido-2-methylpropanesulfonic acid (AMPS, purchased from Shanghai Aladdin Biochemical Technology Co., Ltd., 32g), N-vinylpyrrolidone (NVP, purchased from Shanghai Aladdin Biochemical Technology Co., Ltd., 12g), and phosphonic acid-containing functional monomers. The inorganic nano-core-shell synergist includes a core and a shell covering the core. The surface of the core is grafted with organophosphonate compounds through chemical bonds to form a core-shell structure. The raw material for the core is nano-silica (10g, particle size 20nm), and the organophosphonate compound is 2-carboxyethylphenylphosphonic acid (5g, purchased from Hubei Longxin Chemical Industry Co., Ltd., CEPPA).

[0058] The viscosity-average molecular weight of the three-dimensional network polymer is 6 million. The phosphonic acid functional monomer is vinylphosphonic acid (VPA, purchased from Shanghai Aladdin Biochemical Technology Co., Ltd., 16g).

[0059] This embodiment also provides a method for preparing the composite flocculant for hydrometallurgical processing based on phosphonic acid groups and nano-enhanced properties, the specific process of which is as follows: 10 g of SiO2 with a particle size of 20 nm was dispersed in 200 mL of anhydrous ethanol and sonicated for 30 minutes. 3 g of silane coupling agent (γ-aminopropyltriethoxysilane) was added, and the mixture was refluxed at 80 °C for 6 hours. After centrifugation, washing, and drying, aminated SiO2 was obtained. The aminated SiO2 was dispersed in 150 mL of N,N-dimethylformamide (DMF), and 5 g of 2-carboxyethylphenylphosphonic acid (CEPPA) and 2 g of 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride (EDC) catalyst were added. The mixture was reacted at 60 °C for 12 hours. After centrifugation, washing with ethanol and water, and vacuum drying, the inorganic nano-core-shell synergist was obtained.

[0060] Add 300g of water to a four-necked flask and dissolve acrylamide (AM, 100g), 2-acrylamido-2-methylpropanesulfonic acid (AMPS, 32g), N-vinylpyrrolidone (NVP, 12g), and N-vinylphosphonic acid (VPA, 16g). Adjust the pH to 6.5 with NaOH. Add the crosslinking agent N,N'-methylenebisacrylamide (MBA, 0.16g) and the molecular weight regulator sodium hypophosphite (0.5g). Purge with nitrogen for 30 minutes. Add 30g of the prepared inorganic nano-core-shell synergist and homogenize for 15 minutes. Heat to 25-30℃ and add the initiator (ammonium persulfate 0.8g + sodium bisulfite 0.4g, dissolved in 10mL of water). React for 5 hours to obtain a viscous hydrogel. Add 5g sodium citrate and 5g PEG-400 to the hydrogel, stir to homogenize, and then spray dry (inlet air 180℃, outlet air 90℃) to obtain white porous microsphere composite flocculant product S-1.

[0061] Example 2 This embodiment provides a composite flocculant for hydrometallurgical processing based on phosphonic acid groups and nano-enhancing. The only difference from Example 1 is that the content of phosphonic acid groups is adjusted to 5% (i.e., AM, 100g; AMPS, 38g; NVP, 14g; VPA, 8g), while the other dosages are the same as in Example 1.

[0062] This embodiment also provides a method for preparing a composite flocculant for hydrometallurgical processing with the phosphonic acid group and nano-enhanced properties. Only the content of the phosphonic acid group is adjusted, and the rest of the process is the same as in Example 1, to obtain composite flocculant product S-2.

[0063] Example 3 This embodiment provides a composite flocculant for hydrometallurgical processing based on phosphonic acid groups and nano-enhancing. The only difference from Example 1 is that the content of phosphonic acid groups is adjusted to 15% (i.e., AM, 100g; AMPS, 26g; NVP, 10g; VPA, 24g), while the other dosages are the same as in Example 1.

[0064] This embodiment also provides a method for preparing a composite flocculant for hydrometallurgical processing with the phosphonic acid group and nano-enhanced properties. Only the content of the phosphonic acid group is adjusted, and the rest of the process is the same as in Example 1, to obtain composite flocculant product S-3.

[0065] Example 4 This embodiment provides a composite flocculant for hydrometallurgical processing based on phosphonic acid groups and nano-enhancing agents. The only difference from Example 1 is that the content of the inorganic nano-core-shell synergist is adjusted to 16g, accounting for 10% of the total monomer content, while the remaining dosages are the same as in Example 1.

[0066] This embodiment also provides a method for preparing a composite flocculant for hydrometallurgical processing with the phosphonic acid group and nano-enhanced properties. Only the content of the inorganic nano-core-shell enhancer is adjusted, and the rest of the process is the same as in Example 1, to obtain composite flocculant product S-4.

[0067] Example 5 This embodiment provides a composite flocculant for hydrometallurgical processing based on phosphonic acid groups and nano-enhancing agents. The only difference from Example 1 is that the content of the inorganic nano-core-shell synergist is adjusted to 48g, accounting for 30% of the total monomer content, while the remaining dosages are the same as in Example 1.

[0068] This embodiment also provides a method for preparing a composite flocculant for hydrometallurgical processing with the phosphonic acid group and nano-enhanced properties. Only the content of the inorganic nano-core-shell enhancer is adjusted, and the rest of the process is the same as in Example 1, to obtain composite flocculant product S-5.

[0069] Example 6 This embodiment provides a composite flocculant for hydrometallurgical processing based on phosphonic acid groups and nano-enhancing. The only difference from Example 1 is that VPA (16g) is replaced with AMPP (16g), while the other dosages are the same as in Example 1.

[0070] This embodiment also provides a method for preparing a composite flocculant for hydrometallurgical processing with the phosphonic acid group and nano-enhanced properties. Only the amount of the above materials is adjusted, and the rest of the process is the same as in Example 1, to obtain composite flocculant product S-6.

[0071] Example 7 This embodiment provides a composite flocculant for hydrometallurgical processing based on phosphonic acid groups and nano-enhancing. The only difference from Example 1 is that VPA (16g) is replaced with HEVP (16g), while the other dosages are the same as in Example 1.

[0072] This embodiment also provides a method for preparing a composite flocculant for hydrometallurgical processing with the phosphonic acid group and nano-enhanced properties. Only the amount of the above materials is adjusted, and the rest of the process is the same as in Example 1, to obtain composite flocculant product S-7.

[0073] Example 8 This embodiment provides a composite flocculant for hydrometallurgical processing based on phosphonic acid groups and nano-enhancing. The only difference from Example 1 is that nano-silica (10g, particle size 20nm) is replaced with nano-titanium dioxide (10g, particle size 20nm), while the other dosages are the same as in Example 1.

[0074] This embodiment also provides a method for preparing a composite flocculant for hydrometallurgical processing with the phosphonic acid group and nano-enhanced properties. Only the amount of the above-mentioned materials is adjusted, and the rest of the process is the same as in Example 1, to obtain composite flocculant product S-8.

[0075] Example 9 This embodiment provides a composite flocculant for hydrometallurgical processing based on phosphonic acid groups and nano-enhancing. The only difference from Example 1 is that nano-silica (10g, particle size 20nm) is replaced with nano-zirconia (10g, particle size 20nm), while the other dosages are the same as in Example 1.

[0076] This embodiment also provides a method for preparing a composite flocculant for hydrometallurgical processing with the phosphonic acid group and nano-enhanced properties. Only the amount of the above materials is adjusted, and the rest of the process is the same as in Example 1, to obtain composite flocculant product S-9.

[0077] Comparative Example 1 This comparative example provides a composite flocculant: The only difference from Example 1 is that the monomers are only AM (110g), AMPS (40g), and NVP (10g), without VPA, while the other dosages are the same as in Example 1.

[0078] This embodiment also provides a method for preparing the composite flocculant, only adjusting the amount of the above-mentioned materials, while the rest of the process is the same as in Example 1, to obtain composite flocculant product D-1.

[0079] Comparative Example 2 This comparative example provides a composite flocculant: The only difference from Example 1 is that the copolymer does not contain the nano-core-shell synergist. The monomers are AM (100g), AMPS (32g), NVP (12g), and VPA (16g), and the other amounts are the same as in Example 1.

[0080] This embodiment also provides a method for preparing the composite flocculant, only adjusting the amount of the above-mentioned materials, while the rest of the process is the same as in Example 1, to obtain composite flocculant product D-2.

[0081] Comparative Example 3 This comparative example provides a composite flocculant: The only difference from Example 1 is that SiO2 is replaced with nano-alumina (γ-Al2O3) with the same particle size (20nm), while the other amounts are the same as in Example 1.

[0082] This embodiment also provides a method for preparing the composite flocculant, only adjusting the amount of the above-mentioned materials, while the rest of the process is the same as in Example 1, to obtain composite flocculant product D-3.

[0083] Comparative Example 4 This embodiment provides a method for preparing a composite flocculant, which differs from Example 1 only in that it uses a physical mixing method. The dried polymer powder (AM, AMPS, NVP, and VPA dosages and ratios are the same as in Example 1) is physically mixed uniformly with nano-core-shell synergist powder at a mass ratio of 16:3. That is, the pre-synthesized organic polymer particles / powder and the pre-prepared inorganic nano-core-shell particles are uniformly blended in a solid state. This process does not involve the breaking or formation of chemical bonds, but only changes the spatial distribution of the materials. The resulting composite flocculant product is D-4.

[0084] Comparative Example 5 This comparative example uses the commercially available Magnafloc® LT series and the high-end competitor, polyacrylamide flocculant D-5.

[0085] Tests were performed on S1-S6 and D1-D5: Based on the composition of the liquid after typical hydrometallurgical processes (such as high-pressure acid leaching of laterite nickel ore), a simulated solution was prepared using reagents such as deionized water, nickel sulfate, cobalt sulfate, magnesium sulfate, aluminum sulfate, and ferric sulfate. The average particle size D was then used as the reference. 50 45μm quartz sand and D 50 A solid suspension composed of 8μm kaolinite mixed at a mass ratio of 7:3, adjusted to a temperature of 90±1℃, pH=1.8±0.1, and Al³⁺. + Concentration 6 g / L, Fe³ + The concentration was 8 g / L, and the total solids content (TSS) was 15% (w / w), simulating a real extreme slurry.

[0086] Test method: Refer to GB / T 16881-2008 "Test Methods for Coagulation and Flocculation in Water" and GB / T 18712-2002 "Test Methods for Performance of Flocculants for Coal Preparation". Take 500 mL of simulated slurry into a stoppered graduated cylinder, quickly add a certain amount of flocculant solution (pre-prepared as a 0.1% solution), invert the cylinder five times to mix thoroughly, immediately start timing, and record the time required for the clarified interface to descend to the 250 mL mark, calculating the settling velocity. After standing for 5 minutes, take the supernatant and measure the turbidity using a Hach 2100N turbidity meter. Filter the bottom slurry and measure the moisture content of the filter cake.

[0087] The initial performance test results are shown in Table 1, with a dosage of 100 ppm for all tests. Table 1 Initial Performance Test Results

[0088] As can be seen, the flocculation performance of the products in this application (S-1 to S-8) under extreme conditions is comprehensively and significantly better than that of the comparative examples and commercially available products, proving the effectiveness of the synergistic design of "phosphonic acid group complexation + nano-enhancement".

[0089] The comparison results of Examples S-1 (phosphonic acid group content 10%) with S-2 (phosphonic acid group content 5%) and S-3 (phosphonic acid group content 15%) show that the flocculation performance reaches the best balance when the VPA content is between 5% and 15%. If the content is too low, the complexing ability will be insufficient, and if it is too high, it may lead to a decrease in the hydrophilicity of the polymer or excessive local cross-linking.

[0090] Examples S-4 and S-5 show that the preferred range for the nano-core-shell synergist is 10% to 30%. If the content is too low, an effective "rigid support-synergistic complexation" network cannot be formed, and the product performance is not significantly different from that of conventional temperature-resistant and salt-resistant flocculants. If the amount added is too high, it will destroy the continuity and flexibility of the polymer matrix, introducing new weaknesses, increasing costs, and even turning the synergistic effect into negative interference. Examples S-1, S-4, and S-5 show that the synergist dosage can exhibit excellent performance within the range of 10% to 30% of the total monomer mass. When the dosage is about 18.7% (S-1), the overall performance reaches its best; when the dosage is close to the lower limit (10%, S-4) or the upper limit (30%, S-5), the performance fluctuates slightly, but is still far superior to the comparative example.

[0091] Examples S-6 and S-7 provide a variety of choices for phosphonic acid groups. When the phosphonic acid groups are replaced with AMPP and HEVP, the flocculants in these examples all have good flocculation performance, with VPA being the preferred choice.

[0092] Examples S-8 and S-9 provide a variety of choices for the core of the nano-core-shell synergist. When the core is replaced with nano-titanium dioxide and nano-zirconia, the flocculants in these examples still have good flocculation performance, with nano-silica being the preferred choice.

[0093] Comparative example D-1 (without VPA) showed significantly insufficient flocculation performance, indicating that simple AMPS / NVP modification cannot withstand high Al³ content. + / Fe³ + Interference. This directly demonstrates the effect of the phosphonic acid group (VPA) on Al³⁺. + / Fe³ + The specific and strong complexing ability of high-valence metal ions is the core mechanism of this application to resist ion interference. Common groups such as carboxyl groups cannot effectively compete to bind high-valence metal ions under this extreme environment.

[0094] Comparative Example D-2 (without nano-core-shell synergist) showed a significant difference in flocculation performance compared to the other examples, demonstrating that the improvement in microstructure by the nano-core-shell synergist greatly enhanced the bridging and trapping capabilities of the flocculant.

[0095] When comparative example D-3 used nano-Al2O3 as the core, the initial performance and long-term stability of the product were significantly lower than those of this application (product S-1). This is because the surface of Al2O3 partially dissolves under strong acid conditions, leading to instability in the grafted layer and the potential introduction of aluminum ions for interference. This result demonstrates the advantages of SiO2 as the core in terms of chemical inertness and structural stability in extreme hydrometallurgical environments.

[0096] Comparative example D-4 (physical mixing) outperformed D-1 but was far inferior to S-1, demonstrating that the interpenetrating network structure formed by "in-situ composite" is crucial for achieving synergistic effects, and that simple physical mixing cannot achieve synergistic effects at the molecular / nanoscale level.

[0097] Comparative Example D-5, even as a commercially available high-end temperature- and salt-resistant flocculant, meets the extremely high Al requirements set in this application. 3+ / Fe 3+ Under these conditions, its performance is still significantly inferior to the product of this application. This fully demonstrates the necessity and superiority of molecular functionalization design targeting specific interfering ions, as general-purpose modification schemes are difficult to meet such extreme operating conditions.

[0098] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

[0099] Furthermore, those skilled in the art will understand that although some embodiments herein include certain features included in other embodiments but not others, combinations of features from different embodiments are intended to be within the scope of this application and form different embodiments. For example, in the foregoing claims, any of the claimed embodiments can be used in any combination. The information disclosed in this background section is intended only to enhance the understanding of the general background of this application and should not be construed as an admission or in any way implying that such information constitutes prior art known to those skilled in the art.

Claims

1. A composite flocculant for hydrometallurgical processes based on phosphonic acid groups and nano-enhanced properties, characterized in that, Based on the total mass of the raw materials of the composite flocculant being 100%, it includes: 70-90% heat-resistant, salt-resistant, and hydrolysis-resistant copolymer, 5-25% inorganic nano-core-shell synergist, and 3-8% buffer dispersant; The temperature-resistant, salt-resistant, and hydrolysis-resistant copolymer is a three-dimensional network polymer obtained by free radical copolymerization of acrylamide, 2-acrylamido-2-methylpropanesulfonic acid, N-vinylpyrrolidone, and phosphonic acid functional monomers. The inorganic nano-core-shell synergist includes a core and a shell covering the core; the surface of the core is formed by chemically grafting organophosphonate compounds to form a core-shell structure.

2. The composite flocculant for hydrometallurgical processing based on phosphonic acid groups and nano-enhanced properties according to claim 1, characterized in that, The viscosity-average molecular weight of the three-dimensional network polymer is 3 million to 8 million.

3. The composite flocculant for hydrometallurgical processing based on phosphonic acid groups and nano-enhanced properties according to claim 1, characterized in that, The phosphonic acid functional monomers include at least one of vinylphosphonic acid, 2-acrylamido-2-methylpropionic acid, and N-(2-hydroxyethyl)vinylphosphonic acid.

4. The composite flocculant for hydrometallurgical processing based on phosphonic acid groups and nano-enhanced properties according to claim 3, characterized in that, Based on the total mass of the raw materials of the three-dimensional network polymer being 100%, the amount of the phosphonic acid-containing functional monomer added is 5-15%.

5. The composite flocculant for hydrometallurgical processing based on phosphonic acid groups and nano-enhanced properties according to claim 4, characterized in that, At least one of the following conditions must be met: a. The raw material of the core includes at least one of nano-silica, nano-titanium dioxide, and nano-zirconium oxide; b. The organophosphonate compounds include 2-carboxyethylphenylphosphonic acid.

6. The composite flocculant for hydrometallurgical processing based on phosphonic acid groups and nano-enhanced properties according to any one of claims 1-5, characterized in that, The buffer dispersant comprises a compound of sodium citrate and polyethylene glycol.

7. The composite flocculant for hydrometallurgical processing based on phosphonic acid groups and nano-enhanced properties according to claim 6, characterized in that, The mass ratio of sodium citrate to polyethylene glycol is 1-3:

1.

8. A method for preparing a composite flocculant for hydrometallurgical processing based on phosphonic acid groups and nano-enhanced properties as described in any one of claims 1-7, characterized in that, include: Preparation of inorganic core-shell synergists: After amination of nanoparticles with an aminosilane coupling agent, they are condensed with an organophosphonate compound in the presence of a catalyst to obtain core-shell particles with phosphonates grafted onto their surface by chemical bonds, thus obtaining inorganic core-shell synergists. Acrylamide, 2-acrylamido-2-methylpropanesulfonic acid, N-vinylpyrrolidone and phosphonic acid-containing functional monomers were dissolved in deionized water, and N,N'-methylenebisacrylamide was added. After adjusting the pH value, a copolymer precursor solution was obtained. The inorganic nano-core-shell synergist was mixed with the copolymer precursor liquid, dispersed, and then mixed with an initiator to carry out an initiation polymerization reaction to obtain an organic-inorganic hybrid hydrogel. The organic-inorganic hybrid hydrogel was mixed and homogenized with sodium citrate and polyethylene glycol, and then dried to obtain the composite flocculant for hydrometallurgical based on phosphonic acid groups and nano-enhanced properties.

9. The preparation method according to claim 8, characterized in that, At least one of the following conditions must be met: A. The amount of N,N'-methylenebisacrylamide added is 0.05-0.15% of the total mass of the acrylamide, the 2-acrylamido-2-methylpropanesulfonic acid, the N-vinylpyrrolidone, and the phosphonic acid-containing functional monomer; B. Adjust the pH value to 6-7; C. The initiator comprises an ammonium persulfate / sodium bisulfite redox system; the amount of the initiator added is 0.1-0.5% of the total mass of the acrylamide, the 2-acrylamido-2-methylpropanesulfonic acid, the N-vinylpyrrolidone, and the phosphonic acid-containing functional monomer; D. The reaction temperature for initiating the polymerization reaction is 25-30℃, and the reaction time is 4-6 hours.

10. The application of the composite flocculant for hydrometallurgical processing based on phosphonic acid groups and nano-enhanced properties as described in any one of claims 1-7, characterized in that, The composite flocculant is used for materials containing high concentrations of Al. 3+ and / or Fe 3+ Solid-liquid separation of ore slurry in wet smelting.

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