Phosphinyl covalently modified composite adsorbent material, and preparation method and use thereof

Abstract

The present application relates to a kind of phosphine oxy group covalent modification composite adsorption material and its preparation method and purposes, the preparation method includes the following steps: (1) mixing dopamine hydrochloride, phosphine-containing substrate, tris-hydroxymethyl aminomethane hydrochloride and sodium hydroxide in solvent, to obtain mixed solution;(2) the mixed solution obtained in step (1) and solid phase material are mixed, then oscillation reaction is carried out, to obtain solid-liquid mixture;(3) the solid-liquid mixture obtained in step (2) is carried out solid-liquid separation, and the solid phase part obtained is sequentially washed and dried, to obtain phosphine oxy group covalent modification composite adsorption material.The phosphine oxy group covalent modification composite adsorption material provided by the present application has excellent adsorption selectivity and material stability, and can be used for the high-selectivity separation and recovery of rare metals indium and gallium.

Description

Technical Field

[0001] This invention relates to the field of electronic waste treatment and disposal, specifically to a phosphoxy-covalently modified composite adsorbent material, its preparation method, and its uses. Background Technology

[0002] With the increasing prominence of fossil fuel depletion globally and the growing awareness of environmental protection, the new energy industry has developed rapidly, with photovoltaic power generation being a key representative. In today's photovoltaic module market, second-generation thin-film photovoltaic modules, represented by copper indium gallium selenide (CIGS) modules, are rapidly emerging due to their advantages such as flexibility, high photoelectric conversion efficiency, and good performance in low-light conditions. The key component of CIGS photovoltaic modules is copper indium gallium selenide alloy, which contains indium and gallium, both rare metal elements with low abundance and extremely dispersed distribution in the Earth's crust. Furthermore, since indium and gallium are widely used in low-carbon technologies such as solar cells, electronic semiconductors, and radio, a future supply shortage of indium and gallium is anticipated. Therefore, selectively separating and recycling indium and gallium from waste CIGS photovoltaic modules can maximize the utilization life of rare metals, alleviate their supply shortage, and is crucial for promoting the sustainable development of the photovoltaic industry and other low-carbon technology industries, providing a stable resource guarantee for the future development of green energy.

[0003] Adsorption is one of the main technologies for metal ion recovery. However, in practical applications, the adsorption effect of adsorbent materials on the target metal element is often interfered with by other impurity metal elements. Therefore, adsorption selectivity has become an important indicator for evaluating the adsorption capacity of materials. Currently, some studies use chemical modification methods to functionalize solid-phase materials, enhancing their selective adsorption capacity by directionally loading chemical groups while retaining the advantages of stable physicochemical properties.

[0004] CN113149123A discloses a method for selectively adsorbing and recovering precious metal ions from wastewater using a modified polymer adsorbent. The adsorbent is prepared by mixing various reaction substrates and a supporting substrate (porous adsorption material) in an organic solvent to obtain a solid-liquid mixture. Subsequently, the solid-liquid mixture is heated under a protective gas atmosphere to obtain a modified polymer mixture. The modified polymer mixture is then cooled to room temperature, followed by washing, centrifugation, and drying to obtain the modified polymer adsorbent. The modified polymer adsorbent obtained by this method exhibits advantages such as high selectivity, high adsorption capacity, and stable performance for precious metal ions. However, this method requires the use of large amounts of organic solvents and necessitates heating the reaction at 60-120℃ for 4-24 hours, resulting in high energy consumption and cost, as well as significant pollution, posing potential risks to the ecological environment and human health.

[0005] CN109261124A discloses an activated carbon adsorbent for removing heavy metal ions from water and its preparation method. The method first generates Fe3O4 in situ and loads it onto the surface of activated carbon particles to obtain magnetic activated carbon. Then, benzoyl peroxide, an initiator, is adsorbed onto the surface of the magnetic activated carbon particles, followed by polymerization to form a polystyrene layer. Further, -SO3H is introduced onto the polystyrene surface using triethyl phosphate and SO3 as sulfonating agents to obtain a composite activated carbon adsorbent. The composite activated carbon adsorbent obtained by this method can selectively remove Ni from water. 2+ Pb 2+ Co 2+ Cd 2+ It can absorb various heavy metal ions, but the preparation process of this adsorbent requires a large amount of organic reagents and needs to be carried out at 220-250℃ for 4-6 hours. The steps are complicated, and the energy consumption and cost are high, with a significant environmental risk.

[0006] In summary, although existing research has employed various chemical modification methods to functionalize solid materials and enable them to exhibit adsorption selectivity, these methods often require special conditions such as high temperature and high pressure, and involve the use of large quantities of chemical reagents, including strong acids, strong bases, strong oxidants, and highly toxic organic reagents. Furthermore, the procedures are cumbersome, the reaction conditions are complex, and the costs are high, which greatly limits the practical application of the materials.

[0007] Therefore, it is of great significance to provide a composite adsorbent material that has mild and simple modification conditions, is environmentally friendly, low in cost, has stable adsorption performance, and excellent selective separation effect. Summary of the Invention

[0008] To address the above problems, the present invention aims to provide a phosphoxy-covalently modified composite adsorbent material, its preparation method, and its applications. Compared with the prior art, the phosphoxy-covalently modified composite adsorbent material provided by the present invention has excellent adsorption selectivity and material stability, and can be used for the highly selective separation and recovery of rare metals indium and gallium. The preparation method provided by the present invention has the advantages of simple operation, mild conditions, green environmental protection, and low cost. It can functionalize and modify solid-phase material carriers with phosphoxy groups to obtain composite adsorbent materials with excellent adsorption selectivity.

[0009] To achieve this objective, the present invention employs the following technical solution:

[0010] In a first aspect, the present invention provides a method for preparing a phosphoxy-covalently modified composite adsorbent material, the preparation method comprising the following steps:

[0011] (1) Mix dopamine hydrochloride, phosphine-containing substrate, tris(hydroxymethyl)aminomethane hydrochloride and sodium hydroxide in a solvent to obtain a mixed solution;

[0012] (2) Mix the mixed solution and solid material obtained in step (1), and then perform an oscillating reaction to obtain a solid-liquid mixture;

[0013] (3) The solid-liquid mixture obtained in step (2) is subjected to solid-liquid separation, and the obtained solid phase is washed and dried in sequence to obtain phosphoxy-covalently modified composite adsorbent material.

[0014] In this invention, a phosphine-containing substrate is introduced and reacted with dopamine hydrochloride under weakly alkaline conditions. On one hand, dopamine hydrochloride spontaneously undergoes oxidative polymerization in the weakly alkaline solution to generate polydopamine, while the phosphine-containing substrate also copolymerizes with dopamine, ultimately forming a tightly adhered polymer film on the support surface, allowing the phosphine-containing substrate to simultaneously adhere to the support surface. On the other hand, the phosphine-containing substrate undergoes an Atherton-Todd reaction with polydopamine, covalently linking to the polymer film. That is, the preparation method provided by this invention, through the synergistic effect of dopamine copolymerization and the Atherton-Todd reaction, enables the modification of phosphoxy functionalized groups onto the surface of a solid material, obtaining an adsorbent material with excellent adsorption selectivity for rare metals gallium and indium. Furthermore, due to the tight adhesion of the polymer film, the resulting adsorbent material exhibits excellent cycling stability.

[0015] The present invention provides a preparation method that can complete the functional modification of solid-phase materials without using strong acids, strong bases, strong oxidants and highly toxic organic reagents. It has the advantages of mild and simple modification conditions, green and environmentally friendly, and low cost. Compared with existing neutral phosphonic oxygen extractants, the adsorbent material provided by the present invention has better compatibility with water, is easier to contact indium and gallium elements in solution, and has significant advantages in adsorption selectivity and adsorption capacity.

[0016] Preferably, the phosphine-containing substrate in step (1) includes an organic compound containing a phosphoxy group.

[0017] Preferably, the phosphono-containing organic compound includes any one or a combination of at least two of diethyl phosphite, diisopropyl phosphite, phenylphosphonic acid, ethyl phenylphosphonate, or dimethylphosphine oxide, wherein typical but non-limiting combinations include a combination of diethyl phosphite and diisopropyl phosphite or a combination of phenylphosphonic acid and ethyl phenylphosphonate.

[0018] In this invention, the phosphine-containing substrate is a phosphine-containing substrate capable of undergoing the Atherton-Todd reaction, and is divided into three categories according to the different grafting structures of phosphine atoms, including: (i) O,O-dialkylphosphonates, (ii) hypophosphites and (iii) dialkylphosphine oxides; further, the representative organic compounds of (i) are preferably diethyl phosphite and diisopropyl phosphite, the representative organic compounds of (ii) are preferably phenylphosphine acid and ethyl phenylphosphonate, and the representative organic compounds of (iii) are preferably dimethylphosphine oxide.

[0019] Preferably, the solvent includes water.

[0020] Preferably, the molar ratio of dopamine hydrochloride, tris(hydroxymethyl)aminomethane hydrochloride, sodium hydroxide, and water is (0.5-5):(0.5-5):(2-20):11000, for example, 0.5:0.5:2:11000, 1:0.5:2:11000, 2:0.5:2:11000, 3:0.5:2:11000, 4:0.5:2:11000, 5:0.5:2:11000, 0.5:1:2:11000, 0.5:2:2:11000, 0.5:4:2:1100 0, 0.5:5:2:11000, 0.5:0.5:4:11000, 0.5:0.5:6:11000, 0.5:0.5:8:11000, 0.5:0.5:10:11000, 0.5:0.5:12:11000, 0.5:0.5:14:11000, 0.5:0.5:16:11000, 0.5:0.5:18:11000, or 0.5:0.5:20:11000, but not limited to the listed values, other unlisted values ​​within the range are also applicable.

[0021] In this invention, it is preferable to control the molar ratio of dopamine hydrochloride, tris(hydroxymethyl)aminomethane hydrochloride, sodium hydroxide and water, which can further adjust the thickness of the polymer film and maintain a well-developed pore structure.

[0022] Preferably, the molar ratio of dopamine hydrochloride to the phosphine-containing substrate is (1-3):(10-20), for example, it can be 1:10, 1:12, 1:14, 1:16, 1:18, 1:20, 2:10, 2:12, 2:14, 2:16, 2:18, 3:10, 3:12, 3:14, 3:16 or 3:20, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0023] In this invention, the molar ratio of dopamine hydrochloride to phosphine-containing substrate is preferably controlled, which can regulate the thickness of the polymer film and the degree of phosphooxy modification, thereby achieving high adsorption selectivity and adsorption capacity.

[0024] Preferably, the mixing temperature in step (1) is 15-35℃, for example, it can be 15℃, 16℃, 18℃, 20℃, 22℃, 24℃, 26℃, 28℃, 30℃, 32℃, 34℃ or 35℃, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0025] Preferably, the mixing time in step (1) is 0.1-2h, for example, it can be 0.1h, 0.2h, 0.4h, 0.6h, 0.8h, 1h, 1.2h, 1.4h, 1.6h, 1.8h or 2h, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0026] Preferably, the solid material in step (2) includes any one or a combination of at least two of porous materials, non-porous materials, or nanomaterials.

[0027] Preferably, the porous material comprises any one or a combination of at least two of activated carbon, carbon gel, resin, activated alumina, mesoporous silica, silica gel, zeolite, or bentonite, wherein typical but non-limiting combinations include a combination of activated carbon and mesoporous silica or a combination of zeolite and bentonite.

[0028] Preferably, the non-porous material comprises any one or a combination of at least two of fibrous materials, kaolin, metal oxides, or metal hydroxides, wherein typical but non-limiting combinations include a combination of fibrous materials and metal oxides or a combination of metal oxides and metal hydroxides.

[0029] Preferably, the nanomaterial includes any one or a combination of at least two of carbon nanotubes, graphene, or titanium dioxide nanotubes, wherein typical but non-limiting combinations include a combination of carbon nanotubes and graphene or a combination of graphene and titanium dioxide nanotubes.

[0030] Preferably, the solid material includes coconut shell activated carbon.

[0031] In this invention, coconut shell activated carbon is preferred not only because its preparation method is simple and inexpensive, but also because it has excellent specific surface area and pore structure, as well as strong adsorption capacity.

[0032] Preferably, the BJH desorption pore size of the coconut shell activated carbon is 2-50 nm, for example, it can be 2 nm, 5 nm, 10 nm, 15 nm, 20 nm, 25 nm, 30 nm, 35 nm, 40 nm, 45 nm or 50 nm, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable, preferably 2-5 nm.

[0033] Preferably, the BET specific surface area of ​​the coconut shell activated carbon is 1000-1800 m². 2 / g, for example, could be 1000m 2 / g, 1050m 2 / g、1100m 2 / g、1150m 2 / g、1200m 2 / g、1250m 2 / g、1300m 2 / g, 1350m 2 / g, 1400m 2 / g, 1450m 2 / g, 1500m 2 / g, 1550m 2 / g, 1600m 2 / g、1650m 2 / g、1700m 2 / g、1750m 2 / g or 1800m 2 / g, but not limited to the listed values; other unlisted values ​​within the range are also applicable, preferably 1600-1800m. 2 / g.

[0034] In this invention, it is preferable to control the BJH desorption pore size and BET specific surface area of ​​coconut shell activated carbon within a specific range, which can maximize the loading of polymer film and the degree of phosphooxy modification, while providing sufficient contact area and reaction space for the combination of phosphooxy groups with metal ions in solution, thereby increasing the metal ion adsorption capacity of the adsorption material.

[0035] Preferably, the particle size of the coconut shell activated carbon is 60-850 μm, for example, it can be 60 μm, 70 μm, 80 μm, 90 μm, 100 μm, 150 μm, 200 μm, 250 μm, 300 μm, 350 μm, 400 μm, 450 μm, 500 μm, 550 μm, 600 μm, 650 μm, 700 μm, 750 μm, 800 μm or 850 μm, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable, preferably 250-850 μm.

[0036] Preferably, the solid-liquid ratio of the solid material to the mixed solution in step (2) is (0.1-0.3):20g / mL, for example, it can be 0.1:20g / mL, 0.12:20g / mL, 0.15:20g / mL, 0.18:20g / mL, 0.2:20g / mL, 0.22:20g / mL, 0.25:20g / mL, 0.28:20g / mL or 0.3:20g / mL, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0037] Preferably, the rotational speed of the oscillation reaction is 130-180 r / min, for example, it can be 130 r / min, 132 r / min, 135 r / min, 138 r / min, 140 r / min, 142 r / min, 145 r / min, 148 r / min, 150 r / min, 152 r / min, 155 r / min, 158 r / min, 160 r / min, 162 r / min, 165 r / min, 168 r / min, 170 r / min, 172 r / min, 175 r / min or 180 r / min, but is not limited to the listed values, and other unlisted values ​​within the range are also applicable.

[0038] Preferably, the temperature of the oscillation reaction is 15-45℃, for example, it can be 15℃, 16℃, 18℃, 20℃, 22℃, 24℃, 26℃, 28℃, 30℃, 32℃, 34℃, 36℃, 38℃, 40℃, 42℃, 44℃ or 45℃, but is not limited to the listed values, and other unlisted values ​​within the range are also applicable.

[0039] Preferably, the oscillation reaction time is 10-25h, for example, it can be 10h, 11h, 12h, 13h, 14h, 15h, 16h, 17h, 18h, 19h, 20h, 21h, 22h, 23h, 24h or 25h, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0040] Preferably, the drying temperature is 40-100℃, for example, it can be 40℃, 42℃, 45℃, 48℃, 50℃, 52℃, 55℃, 58℃, 60℃, 62℃, 65℃, 68℃, 70℃, 72℃, 75℃, 78℃, 80℃, 82℃, 85℃, 88℃, 90℃, 92℃, 95℃, 98℃ or 100℃, but is not limited to the listed values, and other unlisted values ​​within the range are also applicable.

[0041] Preferably, the drying time is 4-20 hours, for example, it can be 4 hours, 6 hours, 8 hours, 10 hours, 12 hours, 14 hours, 15 hours, 18 hours or 20 hours, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0042] As a preferred embodiment of the first aspect of the present invention, the preparation method includes the following steps:

[0043] (1) Dopamine hydrochloride, phosphine-containing substrate, tris(hydroxymethyl)aminomethane hydrochloride and sodium hydroxide are mixed in water at a temperature of 15-35℃ and a mixing time of 0.1-2h to obtain a mixed solution;

[0044] The phosphono-containing organic compound includes any one or a combination of at least two of diethyl phosphite, diisopropyl phosphite, phenylphosphonic acid, ethyl phenylphosphonate, or dimethylphosphonic acid oxide; the molar ratio of dopamine hydrochloride, tris(hydroxymethyl)aminomethane hydrochloride, sodium hydroxide, and water is (0.5-5):(0.5-5):(2-20):11000; and the molar ratio of dopamine hydrochloride to the phosphonic substrate is (1-3):(10-20).

[0045] (2) The mixed solution and solid material obtained in step (1) are mixed at a solid-liquid ratio of (0.1-0.3):20 g / mL, and then the mixture is subjected to a shaking reaction at a speed of 130-180 r / min, a temperature of 15-45℃, and a time of 10-25 h to obtain a solid-liquid mixture.

[0046] The solid material includes coconut shell activated carbon, which has a BJH desorption pore size of 2-5 nm and a BET specific surface area of ​​1600-1800 m². 2 / g, with a particle size of 60-850μm;

[0047] (3) The solid-liquid mixture obtained in step (2) is subjected to solid-liquid separation, the obtained solid phase is washed, and then dried at 40-100℃ for 4-20h to obtain phosphoxy-covalently modified composite adsorbent material.

[0048] In a second aspect, the present invention provides a phosphoxy-covalently modified composite adsorbent material, wherein the phosphoxy-covalently modified composite adsorbent material is obtained by the preparation method of the phosphoxy-covalently modified composite adsorbent material described in the first aspect of the present invention; the phosphoxy-covalently modified composite adsorbent material comprises a solid phase material carrier and a polymer film layer coated on the solid phase material carrier; the polymer film layer is grafted with phosphoxy functionalized groups.

[0049] In the phosphoxy-covalently modified composite adsorbent material provided by this invention, a polymer film layer formed by the self-polymerization of dopamine and the copolymerization of phosphine-containing substrate and dopamine adheres to the surface of the solid-phase material support. Simultaneously, the surface of the polymer film layer is covalently linked with abundant phosphoxy-functionalized groups. The adsorbent material provided by this invention not only possesses high adsorption capacity and high adsorption selectivity, but also stable physicochemical properties and good recyclability.

[0050] Thirdly, the present invention provides an application of the phosphoxy-covalently modified composite adsorbent material as described in the second aspect of the present invention, wherein the phosphoxy-covalently modified composite adsorbent material is used for selectively separating and recovering rare metal elements in a solution; the rare metal elements include indium and / or gallium.

[0051] By using the phosphoxy-covalently modified composite adsorbent material provided by this invention and adjusting the pH value of the solution, highly efficient selective adsorption of indium and gallium can be achieved. The adsorbed material is then desorbed, thereby enabling highly selective separation and recovery of indium and gallium.

[0052] Preferably, the solution comprises an acidic leachate of copper indium gallium selenide (CIGS) photovoltaic modules.

[0053] In this invention, the phosphoxy-based covalently modified composite adsorbent material can be used for the adsorption of recycled electronic waste solutions, such as for the acidic leachate of waste copper indium gallium selenide photovoltaic modules, thereby achieving the purpose of separating and recovering indium and gallium from photovoltaic modules, alleviating the problem of supply shortage of rare elements indium and gallium, and promoting the sustainable development of the photovoltaic industry.

[0054] Preferably, the method for selectively separating and recovering indium and gallium from solution using the phosphoxy-covalently modified composite adsorbent material includes the following steps:

[0055] (a) A mixed acidic leachate and a phosphono-oxygen covalently modified composite adsorbent are subjected to a first adsorption and solid-liquid separation to obtain a first filtrate and a first filter residue. Then, the first filtrate and the phosphono-oxygen covalently modified composite adsorbent are mixed and subjected to a second adsorption and solid-liquid separation to obtain a second filtrate and a second filter residue. Both the first and second adsorption are carried out at a first pH value.

[0056] (b) The second filtrate obtained in step (a) and the phosphoxy-covalently modified composite adsorbent material are mixed and subjected to three adsorption and solid-liquid separation processes to obtain a third filtrate and a third filter residue. Then, the third filtrate and the phosphoxy-covalently modified composite adsorbent material are mixed and subjected to four adsorption and solid-liquid separation processes to obtain a fourth filtrate and a fourth filter residue. The three adsorption processes and the four adsorption processes are all carried out at the second pH value.

[0057] (c) The first and second filter residues obtained in step (a) are desorbed in the first acid solution, and then solid-liquid separation is performed to obtain indium recovery solution and regenerated adsorbent material; the third and fourth filter residues obtained in step (b) are desorbed in the second acid solution, and then solid-liquid separation is performed to obtain gallium recovery solution and regenerated adsorbent material.

[0058] Preferably, the acidic leachate in step (a) includes the leachate obtained by leaching copper indium gallium selenide photovoltaic modules with nitric acid.

[0059] Preferably, the solid-liquid ratio of the primary adsorption and the secondary adsorption is independently 0.05-0.6 g / L, for example, it can be 0.05 g / L, 0.1 g / L, 0.15 g / L, 0.2 g / L, 0.25 g / L, 0.3 g / L, 0.35 g / L, 0.4 g / L, 0.45 g / L, 0.5 g / L, 0.55 g / L or 0.6 g / L, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0060] Preferably, the first pH value is in the range of 0.3-0.8, for example, it can be 0.3, 0.4, 0.5, 0.6, 0.7 or 0.8, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0061] Preferably, the solid-liquid ratio of the third and fourth adsorption processes is independently 0.05-0.6 g / L, for example, it can be 0.05 g / L, 0.1 g / L, 0.15 g / L, 0.2 g / L, 0.25 g / L, 0.3 g / L, 0.35 g / L, 0.4 g / L, 0.45 g / L, 0.5 g / L, 0.55 g / L or 0.6 g / L, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0062] Preferably, the range of the second pH value is 1.8-2.3, for example, it can be 1.8, 1.9, 2, 2.1, 2.2 or 2.3, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0063] Preferably, the first acid solution comprises a nitric acid solution.

[0064] Preferably, the concentration of the first acid solution is 1-3 mol / L, for example, it can be 1 mol / L, 1.2 mol / L, 1.5 mol / L, 1.8 mol / L, 2 mol / L, 2.2 mol / L, 2.5 mol / L, 2.8 mol / L or 3 mol / L, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0065] Preferably, the second acid solution comprises a nitric acid solution.

[0066] Preferably, the concentration of the second acid solution is 0.1-1 mol / L, for example, it can be 0.1 mol / L, 0.2 mol / L, 0.3 mol / L, 0.4 mol / L, 0.5 mol / L, 0.6 mol / L, 0.7 mol / L, 0.8 mol / L, 0.9 mol / L or 1 mol / L, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0067] As a preferred embodiment of the third aspect of the present invention, the method for selectively separating and recovering indium and gallium from solution using the phosphoxy-covalently modified composite adsorbent material includes the following steps:

[0068] (a) A mixture of acidic leachate and phosphoxy-covalently modified composite adsorbent is subjected to a first adsorption and solid-liquid separation to obtain a first filtrate and a first filter residue. Then, the first filtrate is mixed with the phosphoxy-covalently modified composite adsorbent and subjected to a second adsorption and solid-liquid separation to obtain a second filtrate and a second filter residue. Both the first and second adsorption are carried out under conditions of pH 0.3-0.8, and the solid-liquid ratio of the first and second adsorption is independently 0.05-0.6 g / L.

[0069] (b) The second filtrate obtained in step (a) and the phosphoxy-covalently modified composite adsorbent are mixed and subjected to three adsorption and solid-liquid separation processes to obtain a third filtrate and a third filter residue. Then, the third filtrate and the phosphoxy-covalently modified composite adsorbent are mixed and subjected to four adsorption and solid-liquid separation processes to obtain a fourth filtrate and a fourth filter residue. The three and four adsorption processes are all carried out under conditions of pH 1.8-2.3, and the solid-liquid ratio of the three and four adsorption processes is independently 0.05-0.6 g / L.

[0070] (c) The first and second filter residues obtained in step (a) are desorbed in a nitric acid solution with a concentration of 1-3 mol / L, and then solid-liquid separation is performed to obtain an indium nitrate solution and a regenerated adsorbent material; the third and fourth filter residues obtained in step (b) are desorbed in a nitric acid solution with a concentration of 0.1-1 mol / L, and then solid-liquid separation is performed to obtain a gallium nitrate solution and a regenerated adsorbent material.

[0071] The present invention does not specifically limit the method of solid-liquid separation, and can be any solid-liquid separation method commonly used in the art, such as filtration or centrifugation.

[0072] The regenerated adsorbent material described in this invention can be reused as an adsorbent material in the adsorption process, achieving recycling and exhibiting good stability in use.

[0073] Compared with the prior art, the present invention has the following beneficial effects:

[0074] (1) Compared with existing extractants and adsorbents, the phosphono-oxygenated covalently modified composite adsorbent provided by this invention has higher compatibility with solutions and is more likely to adsorb rare metal elements in solutions, especially exhibiting excellent adsorption selectivity for rare metals indium and gallium. Under optimal conditions, when the pH of the solution is 0.5, the adsorption rate for indium can reach over 69.8%, and the selective separation coefficient SF0 at this point is [missing value]. In X The adsorption rate reaches over 332.8; when the solution pH is 2, the adsorption rate of gallium can reach over 80.5%, and the selective separation coefficient SF at this time is... Ga X It reached 208.6 or higher.

[0075] (2) The phosphoxy-covalently modified composite adsorbent material provided by the present invention has excellent adsorption capacity and is used for highly selective separation and recovery of rare metal elements indium and gallium in solution. It is especially suitable for efficient separation and high-purity recovery of indium and gallium in acidic leachate of waste CIGS photovoltaic modules. Not only is the process green and pollution-free, but it can also alleviate the shortage of indium and gallium supply and promote the sustainable development of the photovoltaic industry.

[0076] (3) In the phosphoxy covalently modified composite adsorbent material provided by the present invention, the phosphoxy functional groups are firmly modified on the solid material carrier by the polymer film layer and the carrier, thereby achieving stable chemical modification and having excellent recyclability.

[0077] (4) The preparation method provided by the present invention is carried out under mild reaction conditions, without the need for special conditions such as high temperature and high pressure, without the use of large amounts of chemical reagents such as strong acid, strong base, strong oxidant and highly toxic organic reagent, and the required amount of chemical reagents is small and inexpensive. The preparation process does not require additional reaction conditions such as heating or pressurization, and has the advantages of simple preparation, environmental friendliness, low cost and low energy consumption. Attached Figure Description

[0078] Figure 1 The liquid-phase nuclear magnetic resonance phosphorus spectrum of the adsorbent material obtained in Example 1 of this invention and ethyl phenylphosphonate (NMR) 31 Comparison of P NMR characterization;

[0079] Figure 2 The liquid phase nuclear magnetic resonance (NMR) spectra of the adsorbent material obtained in Example 1 of this invention and ethyl phenylphosphonate are shown in Figure 1. 1 Comparison of H NMR characterization;

[0080] Figure 3This is a schematic diagram of the process for using the adsorbent material in Example 1 of the present invention to recover indium and gallium from the acidic leachate of waste copper indium gallium selenide photovoltaic modules.

[0081] Figure 4 This is a line graph showing the adsorption rate of various metal ions for the adsorbent material obtained in Example 1 of the present invention at different pH values;

[0082] Figure 5 This is a line graph showing the adsorption rate of the adsorption material of Comparative Example 1 of the present invention for each metal ion at different pH values.

[0083] Figure 6 The figure shows the cyclic stability test results of the adsorption material described in Example 1 of the present invention. Detailed Implementation

[0084] The technical solution of the present invention will be further illustrated below through specific embodiments. Those skilled in the art should understand that the embodiments described are merely illustrative of the present invention and should not be construed as limiting the invention in any way.

[0085] Example 1

[0086] This embodiment provides a method for preparing a phosphoxy-covalently modified composite adsorbent material, the preparation method comprising the following steps:

[0087] (1) Under the conditions of a temperature of 25℃ and a mixing time of 0.5h, 1×10⁻⁶ ppm of the solution was added to 1.1 mol of water. -4 mol dopamine hydrochloride, 1.5 × 10 -3 mol ethyl phenylphosphonate, 1×10 -4 mol of tris(hydroxymethyl)aminomethane hydrochloride, 0.2 × 10 - 3 A mixed solution was obtained by adding sodium hydroxide; the molar ratio of dopamine hydrochloride to ethyl phenylphosphonate was 1:15.

[0088] (2) The mixed solution obtained in step (1) and coconut shell activated carbon (BJH desorption pore size 2.5 nm, BET specific surface area 1700 m²) were mixed at a solid-liquid ratio of 0.2:20 g / mL. 2 / g, with a particle size of 250-850μm), and then subjected to a shaking reaction at a speed of 160r / min, a temperature of 22℃, and a time of 12h to obtain a solid-liquid mixture;

[0089] (3) The solid-liquid mixture obtained in step (2) is filtered, the solid phase is washed, and then dried at 55°C for 7 hours to obtain the phosphoxy-covalently modified composite adsorbent material.

[0090] This embodiment also provides a phosphoxy-covalently modified composite adsorbent material obtained by the above preparation method. The phosphoxy-covalently modified composite adsorbent material includes a solid material carrier and a polymer film layer wrapped on the solid material carrier; the polymer film layer is grafted with phosphoxy functionalized groups.

[0091] Taking Example 1 as an example, liquid-phase nuclear magnetic resonance (NMR) spectroscopy was performed on the obtained phospho-oxygen covalently modified composite adsorbent material (denoted as EPP-PDA) and ethyl phenylphosphonate (denoted as EPP). 31 P NMR, proton NMR (P NMR), 1 The results of the H NMR (H NMR) test are as follows: Figure 1 and Figure 2 As shown.

[0092] from Figure 1 It can be seen that the NMR phosphorus spectrum of ethyl phenylphosphonate (EPP) contains only a single signal peak, while the spectrum of the adsorbent material EPP-PDA shows multiple signal peaks, indicating that the P atoms in the adsorbent material are in multiple chemical environments, proving the successful functionalization of phosphoxy groups.

[0093] from Figure 2 As can be seen from the 1H NMR characterization results, the H atom signal peak attributable to PH in ethyl phenylphosphonate EPP (represented by A in the figure) disappears in the adsorbent material EPP-PDA. This indicates that during the formation of the adsorbent material, ethyl phenylphosphonate and polydopamine underwent an Atherton-Todd reaction that breaks the PH bond, and the phosphoxy functionalized groups were covalently linked to the polymer film.

[0094] Example 2

[0095] This embodiment provides a method for preparing a phosphoxy-covalently modified composite adsorbent material, the preparation method comprising the following steps:

[0096] (1) Under the conditions of a temperature of 15℃ and a mixing time of 2h, 1.5×10⁻⁶ ppm of the solution was added to 1.1 mol of water. -4 mol dopamine hydrochloride, 2×10 -3 mol diethyl phosphite, 1.5 × 10 -4 mol of tris(hydroxymethyl)aminomethane hydrochloride, 0.5 × 10 - 3 A mixed solution was obtained by adding mol of sodium hydroxide; the molar ratio of dopamine hydrochloride to diethyl phosphite was 1.5:20.

[0097] (2) The mixed solution obtained in step (1) and coconut shell activated carbon (BJH desorption pore size 5nm, BET specific surface area 1000m²) were mixed at a solid-liquid ratio of 0.15:20g / mL. 2 / g, with a particle size of 250-850μm), and then subjected to a shaking reaction at a speed of 160r / min, a temperature of 20℃, and a time of 10h to obtain a solid-liquid mixture;

[0098] (3) The solid-liquid mixture obtained in step (2) is filtered, the solid phase is washed, and then dried at 50°C for 6 hours to obtain the phosphoxy-covalently modified composite adsorbent material.

[0099] This embodiment also provides a phosphoxy-covalently modified composite adsorbent material obtained by the above preparation method. The phosphoxy-covalently modified composite adsorbent material includes a solid material carrier and a polymer film layer wrapped on the solid material carrier; the polymer film layer is grafted with phosphoxy functionalized groups.

[0100] Example 3

[0101] This embodiment provides a method for preparing a phosphoxy-covalently modified composite adsorbent material, the preparation method comprising the following steps:

[0102] (1) Under the conditions of a temperature of 35℃ and a mixing time of 0.1h, 2.5×10⁻⁶ ppm of methyl methacrylate (MCMA) was added to 1.1 mol of water sequentially. - 4 mol dopamine hydrochloride, 1×10 -3 mol phenylphosphine, 2×10 -4 mol of tris(hydroxymethyl)aminomethane hydrochloride, 0.7 × 10 - 3 A mixed solution was obtained by adding sodium hydroxide; the molar ratio of dopamine hydrochloride to phenylphosphine was 2.5:10.

[0103] (2) The mixed solution obtained in step (1) and coconut shell activated carbon (BJH desorption pore size 2.5 nm, BET specific surface area 1700 m²) were mixed at a solid-liquid ratio of 0.3:20 g / mL. 2 / g, with a particle size of 250-850μm), and then subjected to a shaking reaction at a speed of 160r / min, a temperature of 25℃, and a time of 15h to obtain a solid-liquid mixture;

[0104] (3) The solid-liquid mixture obtained in step (2) is filtered, the solid phase is washed, and then dried at 60°C for 8 hours to obtain the phosphoxy-covalently modified composite adsorbent material.

[0105] This embodiment also provides a phosphoxy-covalently modified composite adsorbent material obtained by the above preparation method. The phosphoxy-covalently modified composite adsorbent material includes a solid material carrier and a polymer film layer wrapped on the solid material carrier; the polymer film layer is grafted with phosphoxy functionalized groups.

[0106] Example 4

[0107] This embodiment provides a method for preparing a phosphono-oxygenated covalently modified composite adsorbent material. The difference between this method and Example 1 is only in adjusting the amount of ethyl phenylphosphonate added, so that the molar ratio of dopamine hydrochloride to ethyl phenylphosphonate is 1:30.

[0108] Example 5

[0109] This embodiment provides a method for preparing a phosphono-oxygenated covalently modified composite adsorbent material. The difference between this method and Example 1 is only in adjusting the amount of ethyl phenylphosphonate added, so that the molar ratio of dopamine hydrochloride to ethyl phenylphosphonate is 1:5.

[0110] Example 6

[0111] This embodiment provides a method for preparing a phosphoxy-covalently modified composite adsorbent material, which differs from Example 1 only in that the oscillation reaction time is 0.5 h.

[0112] Example 7

[0113] This embodiment provides a method for preparing a phosphono-oxygen-covalently modified composite adsorbent material. The only difference from Example 1 is that the desorption pore size of the coconut shell activated carbon is 9.8 nm, and the BET specific surface area is 500 m². 2 / g.

[0114] Example 8

[0115] This embodiment provides a method for preparing a phosphoxy-covalently modified composite adsorbent material, the only difference from Example 1 being that the phosphine-containing substrate is replaced with dimethylphosphine oxide.

[0116] Example 9

[0117] This embodiment provides a method for preparing a phosphoxy-based covalently modified composite adsorbent material. The only difference from Example 1 is that the coconut shell activated carbon is replaced with mesoporous silica, wherein the mesoporous silica has a BJH desorption pore size of 10 nm and a BET specific surface area of ​​600 m². 2 / g, with a particle size of 200nm-1μm.

[0118] Example 10

[0119] This embodiment provides a method for preparing a phosphoxy-based covalently modified composite adsorbent material. The only difference from Example 1 is that the coconut shell activated carbon is replaced with bamboo-based activated carbon. The bamboo-based activated carbon has a BJH desorption pore size of 4.8 nm and a BET specific surface area of ​​700 m². 2 / g, with a particle size of 60-150μm.

[0120] Comparative Example 1

[0121] This comparative example provides an adsorption material, which is the coconut shell activated carbon from Example 1.

[0122] Application Example 1

[0123] This application example provides a use for a phosphoxy-based covalently modified composite adsorbent material, which is prepared according to Example 1. The use is for recovering indium and gallium from the acidic leachate of waste copper indium gallium selenide (CIGS) photovoltaic modules. The acidic leachate contains 62.8 wt.% Zn by mass. 2+ 16.3 wt.% In 3+ 10.2 wt.% Cu 2+ 6.9 wt.% Ga 3+ 3.2 wt.% Cd 2+ 0.1 wt.% Mg 2+ and 0.5 wt.% Al 3+ ,like Figure 3 As shown, the application includes the following steps:

[0124] (a) A mixture of acidic leachate and phosphoxy-covalently modified composite adsorbent material is subjected to a first adsorption and filtration process to obtain a first filtrate and a first filter residue. Then, the first filtrate and phosphoxy-covalently modified composite adsorbent material are mixed and subjected to a second adsorption and filtration process to obtain a second filtrate and a second filter residue. Both the first and second adsorption processes are carried out at a pH of 0.5 and the solid-liquid ratio during the adsorption process is 0.3 g / L.

[0125] (b) The second filtrate obtained in step (a) and the phosphoxy-covalently modified composite adsorbent material are mixed and subjected to three adsorption and filtration processes to obtain a third filtrate and a third filter residue. Then, the third filtrate and the phosphoxy-covalently modified composite adsorbent material are mixed and subjected to four adsorption and filtration processes to obtain a fourth filtrate and a fourth filter residue. The three and four adsorption processes are all carried out at a pH of 2 and the solid-liquid ratio of the adsorption process is 0.3 g / L.

[0126] (c) Desorb the first and second filter residues obtained in step (a) in a 2 mol / L nitric acid solution, and then filter to obtain an indium nitrate solution and a regenerated adsorbent material; desorb the third and fourth filter residues obtained in step (b) in a 0.5 mol / L nitric acid solution, and then filter to obtain a gallium nitrate solution and a regenerated adsorbent material.

[0127] The regenerated adsorbent material can be reused in steps (a) and (b).

[0128] Application Example 2

[0129] This application example provides a use for a phosphoxy-based covalently modified composite adsorbent material, which is prepared according to Example 2. The use is for recovering indium and gallium from the acidic leaching solution of waste copper indium gallium selenide (CIGS) photovoltaic modules. The acidic leaching solution is the same as in Example 1. The use includes the following steps:

[0130] (a) A mixture of acidic leachate and phosphoxy-covalently modified composite adsorbent material is subjected to a first adsorption and filtration process to obtain a first filtrate and a first filter residue. Then, the first filtrate and phosphoxy-covalently modified composite adsorbent material are mixed and subjected to a second adsorption and filtration process to obtain a second filtrate and a second filter residue. Both the first and second adsorption processes are carried out at a pH of 0.8 and the solid-liquid ratio during the adsorption process is 0.3 g / L.

[0131] (b) The second filtrate obtained in step (a) and the phosphoxy-covalently modified composite adsorbent material are mixed and subjected to three adsorption and filtration processes to obtain a third filtrate and a third filter residue. Then, the third filtrate and the phosphoxy-covalently modified composite adsorbent material are mixed and subjected to four adsorption and filtration processes to obtain a fourth filtrate and a fourth filter residue. The three and four adsorption processes are all carried out at a pH of 2.3 and the solid-liquid ratio of the adsorption process is 0.3 g / L.

[0132] (c) Desorb the first and second filter residues obtained in step (a) in a 3 mol / L nitric acid solution, and then filter to obtain an indium nitrate solution and a regenerated adsorbent material; desorb the third and fourth filter residues obtained in step (b) in a 1 mol / L nitric acid solution, and then filter to obtain a gallium nitrate solution and a regenerated adsorbent material.

[0133] The regenerated adsorbent material can be reused in steps (a) and (b).

[0134] Application Example 3

[0135] This application example provides a use for a phosphoxy-based covalently modified composite adsorbent material, which is prepared in Example 3. The use is for recovering indium and gallium from the acidic leaching solution of waste copper indium gallium selenide (CIGS) photovoltaic modules. The acidic leaching solution is the same as in Example 1. The use includes the following steps:

[0136] (a) A mixture of acidic leachate and phosphoxy-covalently modified composite adsorbent material is subjected to a first adsorption and filtration process to obtain a first filtrate and a first filter residue. Then, the first filtrate and phosphoxy-covalently modified composite adsorbent material are mixed and subjected to a second adsorption and filtration process to obtain a second filtrate and a second filter residue. Both the first and second adsorption processes are carried out at a pH of 0.3 and the solid-liquid ratio during the adsorption process is 0.3 g / L.

[0137] (b) The second filtrate obtained in step (a) and the phosphoxy-covalently modified composite adsorbent material are mixed and subjected to three adsorption and filtration processes to obtain a third filtrate and a third filter residue. Then, the third filtrate and the phosphoxy-covalently modified composite adsorbent material are mixed and subjected to four adsorption and filtration processes to obtain a fourth filtrate and a fourth filter residue. The three and four adsorption processes are all carried out at a pH of 1.8 and the solid-liquid ratio of the adsorption process is 0.3 g / L.

[0138] (c) Desorb the first and second filter residues obtained in step (a) in a 1 mol / L nitric acid solution, and then filter to obtain an indium nitrate solution and a regenerated adsorbent material; Desorb the third and fourth filter residues obtained in step (b) in a 0.1 mol / L nitric acid solution, and then filter to obtain a gallium nitrate solution and a regenerated adsorbent material.

[0139] The regenerated adsorbent material can be reused in steps (a) and (b).

[0140] Application Example Comparative Example 1

[0141] This comparative example provides an application of an adsorbent material, which differs from Application Example 1 only in that it uses the adsorbent material provided in Comparative Example 1.

[0142] The contents of gallium ions and indium ions in the indium nitrate and gallium nitrate solutions obtained in the above application examples and comparative examples were determined, and the recovery rates of gallium and indium were calculated. The results are shown in Table 1. The formula for calculating the recovery rate is:

[0143] Table 1

[0144] Indium recovery rate / % Gallium recovery rate / % Application Example 1 99.9 99.9 Application Example 2 94.5 95.5 Application Example 3 96.4 96.8 Application Comparative Example 1 0.8 2.1

[0145] As can be seen from the data in Table 1, the phosphoxy-based covalently modified composite adsorbent provided by the present invention is used for selectively separating and recovering indium and gallium from the acidic leachate of waste copper indium gallium selenide photovoltaic modules. It has a high recovery rate and selectivity for indium and gallium, and can achieve efficient separation and high-purity recovery of indium and gallium.

[0146] Metal ion adsorption effect test:

[0147] The adsorbent materials obtained in Examples 1-10 and Comparative Example 1 were each placed in a 100 mL stoppered conical flask to prepare a solution containing In. 3+ Ga 3+ Al 3+ Zn 2+ Cd 2+ Cu 2+ Mg 2+ and Ni +A mixed metal solution (each metal ion concentration of 0.1 mmol / L) was prepared and its pH value was adjusted to 0.5, 1, 1.5, 2, 2.5, 3, 3.5, and 4. The solution was added to an Erlenmeyer flask at a solid-liquid ratio of 0.3 g / L and reacted for 8 hours at 25°C and a shaking speed of 160 r / min. The concentration of each metal ion in the mixed solution after reaction was measured at different pH values, and the adsorption rate of the corresponding metal ions was calculated. Table 2 shows the adsorption rate and separation coefficient of indium in each example and comparative example when the pH value is 0.5, and the table 2 shows the adsorption rate and separation coefficient of gallium in each example and comparative example when the pH value is 2.

[0148] The formula for calculating the adsorption rate is as follows: in:

[0149] C i,0 —The initial concentration of metal ions in the solution (mg / L);

[0150] C i,e —The concentration (mg / L) of metal ions in solution when adsorption equilibrium is reached;

[0151] Separation coefficient SF A B The calculation formula is: in:

[0152] C A,0 —The initial concentration (mg / L) of metal ion A in the mixed metal solution;

[0153] C A,e —Equilibrium concentration (mg / L) of metal ion A in the mixed metal solution;

[0154] C B,0 —Initial concentration (mg / L) of metal ion B in the mixed metal solution;

[0155] C B,e —Equilibrium concentration (mg / L) of metal ion B in mixed metal solution;

[0156] Adsorption capacity q i The calculation formula is: in:

[0157] C i,0 —The initial concentration of metal ions in the solution (mg / L);

[0158] C i,e —The concentration (mg / L) of metal ions in solution when adsorption equilibrium is reached;

[0159] V – Volume of the solution (L);

[0160] W – Amount of adsorbent material added (g).

[0161] Taking Example 1 as an example, in the above metal ion adsorption effect test, the adsorption material provided in Example 1, under the conditions of 25℃ and pH=0.5, had a saturated adsorption capacity of 125.09 mg / g for indium ions, and the separation coefficient for separating indium ions from other metal ions was [missing value]. The adsorbent material provided in Example 1 exhibits a saturated adsorption capacity of 140.73 mg / g for gallium ions at 25°C and pH = 2.0, and the separation coefficient for separating gallium ions from other metal ions is [missing value].

[0162] Taking Example 1 and Comparative Example 1 as examples, the adsorption rates of the adsorbent material obtained in Example 1 for each metal ion are as follows: Figure 4 As shown, the adsorption rates of the adsorbent material provided in Comparative Example 1 for each metal ion are as follows: Figure 5 As shown, from Figure 4 and Figure 5 It can be seen that the phosphoxy-covalently modified composite adsorbent material provided by the present invention achieves highly selective adsorption of indium and gallium at pH values ​​of 0.5 and 2 in the mixed metal solution, respectively, while coconut shell activated carbon does not have selective adsorption capacity for indium and gallium, and the adsorption rate of each metal ion is less than 10% in the pH range of 0.5-2.

[0163] Cyclic stability test:

[0164] Taking Example 1 as an example, the adsorbent material was placed in In(NO3)3 and Ga(NO3)3 solutions, respectively. The adsorption conditions for the In(NO3)3 solution were controlled as follows: solid-liquid ratio 0.3 g / L, pH 0.5. Desorption was then performed using a 2 mol / L nitric acid solution. The regenerated adsorbent material obtained after desorption was used to repeat the above adsorption-desorption process. The adsorption conditions for the Ga(NO3)3 solution were controlled as follows: solid-liquid ratio 0.3 g / L, pH 2. Desorption was then performed using a 0.5 mol / L nitric acid solution. The regenerated adsorbent material obtained after desorption was used to repeat the above adsorption-desorption process. The adsorption rates of metal ions at different cycle numbers are as follows: Figure 6 As shown. From Figure 6 It can be seen that after 9 adsorption-desorption cycles, the adsorption material for In... 3+ and Ga 3+ The adsorption rates still reached 85% and 90% respectively, proving that the adsorbent material has excellent cycle stability.

[0165] Table 2

[0166]

[0167] In Table 2, "-" indicates that the data is not available.

[0168] The following points can be observed from the data in Table 2:

[0169] (1) As can be seen from the data in Examples 1-10, the adsorption material provided by the present invention can achieve an adsorption rate of over 69.8% for indium under optimal conditions, and the separation coefficient is [missing information]. It can reach a value of over 332.8, with an adsorption rate of over 80.5% for gallium and a separation coefficient of over 10%. It can reach 208.6 or higher.

[0170] (2) A comprehensive comparison of the data from Examples 1 and 4-5 shows that the only difference between Examples 4-5 and Example 1 is that the molar ratio of dopamine hydrochloride to ethyl phenylphosphonate is not within the preferred range of the present invention. The adsorption selectivity of indium and gallium in Example 1 is significantly better than that in Examples 4-5. It can be seen that the present invention can regulate the thickness of the polymer film and the degree of phosphoxy modification by preferentially controlling the molar ratio of dopamine hydrochloride to ethyl phenylphosphonate, thereby further improving the adsorption amount and adsorption selectivity.

[0171] (3) A comprehensive comparison of the data of Example 1 and Example 6 shows that the only difference between Example 6 and Example 1 is that the time of the oscillation reaction is not within the preferred range of the present invention. The adsorption selectivity of indium and gallium in Example 1 is significantly better than that in Example 6. It can be seen that the present invention can further improve the modification effect by preferably controlling the time of the oscillation reaction within a specific range, thereby improving the adsorption amount and adsorption selectivity.

[0172] (4) A comprehensive comparison of the data from Examples 1 and 7, 9-10 shows that the only difference between Example 7 and Example 1 is that the specific surface area of ​​the coconut shell activated carbon is not within the preferred range of the present invention. The adsorption selectivity for indium and gallium in Example 1 is significantly better than that in Example 7. Thus, the present invention can further improve the adsorption capacity and adsorption selectivity by optimizing and controlling the structural parameters of the coconut shell activated carbon within a specific range. The only difference between Examples 9-10 and Example 1 is that the coconut shell activated carbon is replaced with mesoporous silica and bamboo-based activated carbon, respectively. The adsorption selectivity for indium and gallium in Example 1 is significantly better than that in Examples 9-10. Thus, the present invention can further improve the adsorption capacity and adsorption selectivity by optimizing the use of coconut shell activated carbon and utilizing its excellent specific surface area, pore structure and particle size.

[0173] (5) A comprehensive comparison of the data from Example 1 and Example 8 shows that the only difference between Example 8 and Example 1 is that the phosphine-containing substrate is replaced with dimethylphosphine oxide. The adsorption selectivity of indium and gallium in Example 1 is significantly better than that in Example 8. It can be seen that the present invention can further improve the adsorption amount and adsorption selectivity by optimizing and controlling the type of phosphine-containing substrate.

[0174] (6) Comparing the data of Example 1 and Comparative Example 1, it can be seen that the coconut shell activated carbon used in Comparative Example 1 has a significantly better adsorption selectivity for indium and gallium than the adsorption material provided in Example 1. Therefore, the adsorption material provided by the present invention has excellent adsorption effect and adsorption selectivity. However, when only coconut shell activated carbon is used for adsorption, not only is the adsorption effect poor, but there is also no adsorption selectivity.

[0175] In summary, the phosphoxy-based covalently modified composite adsorbent material provided by this invention has excellent adsorption selectivity and material stability, and can be used for the highly selective separation and recovery of rare metals indium and gallium. The preparation method provided by this invention has the advantages of simple operation, mild conditions, green environmental protection, and low cost. It can modify solid-phase material carriers with phosphoxy-based functionalization to obtain composite adsorbent materials with excellent adsorption selectivity.

[0176] The applicant declares that the above description is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention fall within the protection and disclosure scope of the present invention.

Claims

1. A method for preparing a phosphoxy-covalently modified composite adsorbent material, characterized in that, The preparation method includes the following steps: (1) Mix dopamine hydrochloride, phosphine-containing substrate, tris(hydroxymethyl)aminomethane hydrochloride and sodium hydroxide in a solvent to obtain a mixed solution; (2) The mixed solution obtained in step (1) and the solid material are mixed and then subjected to an oscillating reaction to obtain a solid-liquid mixture; (3) The solid-liquid mixture obtained in step (2) is subjected to solid-liquid separation, and the obtained solid phase is washed and dried in sequence to obtain phosphoxy-covalently modified composite adsorbent material; The phosphine-containing substrate in step (1) includes organic compounds containing phosphoxy groups; The phosphono-containing organic compound includes any one or a combination of at least two of diethyl phosphite, diisopropyl phosphite, phenylphosphonic acid, ethyl phenylphosphonate, or dimethylphosphine oxide.

2. The preparation method according to claim 1, characterized in that, The solvent includes water.

3. The preparation method according to claim 2, characterized in that, The molar ratio of dopamine hydrochloride, tris(hydroxymethyl)aminomethane hydrochloride, sodium hydroxide, and water is (0.5-5):(0.5-5):(2-20):11000.

4. The preparation method according to claim 1, characterized in that, The molar ratio of dopamine hydrochloride to the phosphine-containing substrate is (1-3):(10-20).

5. The preparation method according to claim 1, characterized in that, The mixing temperature in step (1) is 15-35℃.

6. The preparation method according to claim 1, characterized in that, The mixing time in step (1) is 0.1-2 hours.

7. The preparation method according to claim 1, characterized in that, The solid material in step (2) includes any one or a combination of at least two of porous materials, non-porous materials, or nanomaterials.

8. The preparation method according to claim 7, characterized in that, The porous material includes any one or a combination of at least two of the following: activated carbon, carbon gel, resin, activated alumina, mesoporous silica, silica gel, zeolite, or bentonite.

9. The preparation method according to claim 7, characterized in that, The non-porous material includes any one or a combination of at least two of the following: fibrous materials, kaolin, metal oxides, or metal hydroxides.

10. The preparation method according to claim 7, characterized in that, The nanomaterials include any one or a combination of at least two of carbon nanotubes, graphene, or titanium dioxide nanotubes.

11. The preparation method according to claim 1, characterized in that, The solid material includes coconut shell activated carbon.

12. The preparation method according to claim 11, characterized in that, The BJH desorption pore size of the coconut shell activated carbon is 2-50 nm.

13. The preparation method according to claim 12, characterized in that, The BJH desorption pore size of the coconut shell activated carbon is 2-5 nm.

14. The preparation method according to claim 11, characterized in that, The BET specific surface area of ​​the coconut shell activated carbon is 1000-1800 m². 2 / g.

15. The preparation method according to claim 14, characterized in that, The BET specific surface area of ​​the coconut shell activated carbon is 1600-1800 m². 2 / g.

16. The preparation method according to claim 11, characterized in that, The particle size of the coconut shell activated carbon is 60-850 μm.

17. The preparation method according to claim 16, characterized in that, The particle size of the coconut shell activated carbon is 250-850 μm.

18. The preparation method according to claim 1, characterized in that, The solid-liquid ratio of the solid material to the mixed solution in step (2) is (0.1-0.3):20g / mL.

19. The preparation method according to claim 1, characterized in that, The rotational speed of the oscillation reaction is 130-180 r / min.

20. The preparation method according to claim 1, characterized in that, The temperature of the oscillation reaction is 15-45℃.

21. The preparation method according to claim 1, characterized in that, The oscillation reaction lasts for 10-25 hours.

22. The preparation method according to claim 1, characterized in that, The drying temperature in step (3) is 40-100℃.

23. The preparation method according to claim 1, characterized in that, The drying time is 4-20 hours.

24. A phosphoxy-covalently modified composite adsorbent material, characterized in that, The phosphoxy-covalently modified composite adsorbent material is obtained by the preparation method of the phosphoxy-covalently modified composite adsorbent material as described in any one of claims 1-23; The phosphoxy-covalently modified composite adsorbent material includes a solid material carrier and a polymer film layer wrapped on the solid material carrier; The polymer film is grafted with phosphoxy functionalized groups.

25. The use of the phosphoxy-covalently modified composite adsorbent material as described in claim 24, characterized in that, The phosphoxy-covalently modified composite adsorbent material is used for the selective separation and recovery of rare metal elements in solution; The rare metal elements include indium and / or gallium.

26. The use according to claim 25, characterized in that, The solution includes an acidic leachate of copper indium gallium selenide (CIGS) photovoltaic modules.

27. The use according to claim 25, characterized in that, The method for selectively separating and recovering indium and gallium from solution using the phosphoxy-covalently modified composite adsorbent material includes the following steps: (a) A mixed acidic leachate and a phosphono-oxygen covalently modified composite adsorbent are subjected to a first adsorption and solid-liquid separation to obtain a first filtrate and a first filter residue. Then, the first filtrate and the phosphono-oxygen covalently modified composite adsorbent are mixed and subjected to a second adsorption and solid-liquid separation to obtain a second filtrate and a second filter residue. Both the first and second adsorption are carried out at a first pH value. (b) The second filtrate obtained in step (a) and the phospho-oxygen covalently modified composite adsorbent are mixed and subjected to three adsorption and solid-liquid separation processes to obtain a third filtrate and a third filter residue. Then, the third filtrate and the phospho-oxygen covalently modified composite adsorbent are mixed and subjected to four adsorption and solid-liquid separation processes to obtain a fourth filtrate and a fourth filter residue. The three adsorption processes and the four adsorption processes are all carried out at the second pH value. (c) Desorb the first and second filter residues obtained in step (a) in the first acid solution, and then separate the solid and liquid to obtain indium recovery solution and regenerated adsorbent material; desorb the third and fourth filter residues obtained in step (b) in the second acid solution, and then separate the solid and liquid to obtain gallium recovery solution and regenerated adsorbent material.

28. The use according to claim 27, characterized in that, The acidic leachate in step (a) includes the leachate obtained by leaching copper indium gallium selenide photovoltaic modules with nitric acid.

29. The use according to claim 27, characterized in that, The solid-liquid ratio of the primary adsorption and the secondary adsorption is independently 0.05-0.6 g / L.

30. The use according to claim 27, characterized in that, The first pH value is in the range of 0.3-0.

8.

31. The use according to claim 27, characterized in that, The solid-liquid ratios for the third and fourth adsorption processes are each independently 0.05-0.6 g / L.

32. The use according to claim 27, characterized in that, The second pH value ranges from 1.8 to 2.

3.

33. The use according to claim 27, characterized in that, The first acid solution includes a nitric acid solution.

34. The use according to claim 27, characterized in that, The concentration of the first acid solution is 1-3 mol / L.

35. The use according to claim 27, characterized in that, The second acid solution includes a nitric acid solution.

36. The use according to claim 27, characterized in that, The concentration of the second acid solution is 0.1-1 mol / L.

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