Adsorbent for recovering scandium from an acidic solution, method of preparation and use

Abstract

The application belongs to the technical field of rare earth recovery, and particularly relates to an adsorbent for recovering scandium from an acid solution, a preparation method and application, which comprises the following raw materials: monomers, a crosslinking agent and an initiator, the monomers are a mixture of ethylene phosphoric acid and 2-methyl-2-propenoic acid-2-hydroxyethyl ester phosphate, and the molar ratio of ethylene phosphoric acid and 2-methyl-2-propenoic acid-2-hydroxyethyl ester phosphate is 0.1-10:1. The application can adsorb scandium from different acid solutions, and all have good adsorption capacity.

Description

Technical Field

[0001] This invention belongs to the field of rare earth recovery technology, specifically relating to an adsorbent for recovering scandium from acidic solutions, its preparation method, and its application. Background Technology

[0002] Scandium is a member of the rare earth elements. Due to its special properties in optoelectronics, magnetism, acoustics, and heat, it plays an irreplaceable role in fields such as electronics, optics, magnetic materials, and catalysts.

[0003] Scandium lacks independent deposits in nature and is extremely dispersed, making it a typical rare lithophile element. It often occurs alongside other minerals and is typically recovered as a byproduct, which is difficult, costly, and expensive to extract.

[0004] Due to the complex sources and difficult extraction of scandium, the recovery and purification process often involves switching between different acid systems to meet varying requirements. However, different adsorbents exhibit significant differences in adsorption capacity in different acid solutions. Generally, an adsorbent with good adsorption capacity in one acid may not have good adsorption capacity in other acid solutions. Therefore, developing a material capable of adsorbing scandium in different acid systems can avoid the problem of having to replace adsorbents and related equipment due to system switching during scandium recovery, which has practical significance for scandium recovery. Currently, there is a lack of adsorbents that meet this requirement.

[0005] Patent application number 201910244493.6 discloses a method for preparing a resin based on BMAOP and its application in separating scandium and zirconium. The resin is prepared by crosslinking polymerization using di(methacryloyloxyethyl) hydrogen phosphate (BMAOP) as a monomer, dimethyl sulfoxide as a solvent, ethylene glycol dimethacrylate (EGDMA) as a crosslinking agent, and azobisisobutyl cyanide as an initiator, and loading the resin onto the micropores or surface of a support. However, this material preferentially adsorbs zirconium but has a weak adsorption capacity for scandium. It is primarily used for removing trace amounts of zirconium impurities from scandium, but cannot preferentially adsorb scandium from complex systems. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to provide an adsorbent, preparation method and application for recovering scandium from acidic solutions, which can adsorb scandium from different acid solutions and has good adsorption capacity.

[0007] This invention provides an adsorbent for recovering scandium from an acidic solution, comprising the following raw materials: a monomer, a crosslinking agent, and an initiator. The monomer is a mixture of ethylene phosphoric acid and 2-methyl-2-acrylate-2-hydroxyethyl phosphate, wherein the molar ratio of ethylene phosphoric acid to 2-methyl-2-acrylate-2-hydroxyethyl phosphate is 0.1 to 10:1 (preferably 1:1).

[0008] Preferably, the crosslinking agent is ethylene glycol dimethacrylate, and the initiator is azobisisobutyronitrile.

[0009] Preferably, the material further includes a solvent and a carrier, wherein the solvent is dimethyl sulfoxide and the carrier is a porous material, such as a porous silica carrier. The carrier may also be a commercially available product XAD7HP and its series of products, domestically produced white spheres, or other porous materials with good stability.

[0010] Preferably, the weight ratio of the monomer to the crosslinking agent is 0.2~1:0.08~0.4 (preferably 0.6-0.9:0.08-0.4), and the weight ratio of the initiator to the monomer is 0.01~0.05:1, more preferably 0.01-0.03:1.

[0011] Preferably, the weight ratio of the dimethyl sulfoxide to the support is 0.4 to 3:1, more preferably 0.4 to 1.5:1.

[0012] Preferably, the weight ratio of the monomer to the carrier is 0.2-1:1, and the weight ratio of the crosslinking agent to the carrier is 0.08-0.4:1.

[0013] The present invention provides a method for preparing an adsorbent for recovering scandium from an acidic solution, comprising the steps of monomer polymerization under the action of an initiator, and reacting with a crosslinking agent to form a crosslinked structure.

[0014] Preferably, a mixture of monomer, crosslinking agent, initiator and solvent is introduced into the carrier using negative pressure, heated, reacted, and processed to obtain an adsorbent for recovering scandium from an acidic solution; the heating method involves maintaining the temperature at different temperatures for a period of time during the heating process.

[0015] Preferably, the heating method is as follows: maintaining the temperature at 55-65℃ (preferably 60℃) for a period of time (preferably 0.5-1.5 h), then maintaining the temperature at 65-75℃ (preferably 70℃) for a period of time (preferably 1.5-2.5 h), then maintaining the temperature at 75-85℃ (preferably 80℃) for a period of time (preferably 10-12 h), and then maintaining the temperature at 85-95℃ (preferably 90℃) for a period of time (preferably 8-10 h).

[0016] Preferably, the treatment method is to wash with acetone and ultrapure water alternately and then dry (drying temperature is 40-50℃).

[0017] The present invention carries out the reaction under an inert atmosphere. The instrument used can be a rotary evaporator. The negative pressure is formed by evacuating the container. The pressure is preferably controlled below 50 hPa (e.g., 25 hPa). After the mixture of monomer, crosslinking agent, initiator and solvent is introduced into the carrier under the action of negative pressure, it is filled with inert gas (nitrogen or argon), restored to normal pressure, and then heated to carry out the in-situ polymerization reaction.

[0018] This invention provides an application of the adsorbent described above for recovering scandium from an acidic solution. The adsorbent is used to recover scandium. Specifically, the recovery method involves adding the adsorbent to an acidic solution containing scandium for adsorption. The acidic solution is one or more of sulfuric acid, hydrochloric acid, and nitric acid. The concentration of scandium in the acidic solution is 10-10000 ppm (preferably 10-1000 ppm), and it may contain other rare earth and non-rare earth elements. The impurity concentration ranges from 0.1-10000 ppm (preferably 0.1-100 ppm). The adsorption time between the adsorbent and the acidic solution containing scandium is 5-1500 min (preferably 100-360 min), the temperature is 15-80℃ (preferably 25-50℃), and the acidity of the acidic solution containing scandium is 0.00001-6 mol / L. The solid-liquid ratio of the adsorbent to the acidic solution containing scandium is 1g:10-2000mL, preferably 1g:100-1000mL.

[0019] The beneficial effects of this invention are that the adsorbent of this invention can recover scandium from various acidic solutions, such as sulfuric acid, hydrochloric acid, nitric acid and other acid systems. The operation is simple and efficient, and it has good recovery ability. More importantly, it can effectively recover scandium from other rare metals with a high degree of separation. Attached Figure Description

[0020] Figure 1 This is a flowchart illustrating the preparation process of the phosphoric acid functionalized adsorbent according to an embodiment of the present invention.

[0021] Figure 2 Thermogravimetric analysis (TGA) of the phosphoric acid functionalized adsorbent SiHmpVa in an embodiment of the present invention.

[0022] Figure 3 The phosphoric acid functionalized adsorbent SiHmpVa in this embodiment of the invention adsorbs scandium from nitric acid solution.

[0023] Figure 4 The phosphoric acid functionalized adsorbent SiHmpVa in this embodiment of the invention adsorbs scandium from hydrochloric acid solution.

[0024] Figure 5 The phosphoric acid functionalized adsorbent SiHmpVa in this embodiment of the invention adsorbs scandium from sulfuric acid solution.

[0025] Figure 6 The phosphoric acid functionalized adsorbent SiHmpVa, as described in this embodiment of the invention, selectively adsorbs scandium from nitric acid solution. Detailed Implementation

[0026] Example 1 Six g of porous silica support was added to the flask of a rotary evaporator, and the flask was kept rotating at a low speed. The oxygen in the rotary evaporator was replaced twice with nitrogen, followed by evacuation to 25 hPa. Simultaneously, 2.6 g of dimethyl sulfoxide, 1.742 g of 2-methyl-2-acrylate-2-hydroxyethyl phosphate, 0.851 g of ethylene phosphoric acid, 1.514 g of ethylene glycol dimethacrylate, and 0.1 g of azobisisobutyronitrile were mixed sequentially. After the azobisisobutyronitrile was completely dissolved, the mixed oil phase was introduced into the rotary evaporator flask using a pressure difference. The rotation speed was adjusted to ensure thorough mixing of the oil phase with the porous silica support until no obvious agglomeration occurred; at this point, the oil phase was considered to have completely entered the porous silica support. Nitrogen was introduced to restore atmospheric pressure, and then the temperature was increased to initiate the polymerization reaction. An oil bath was used for heating, maintaining 60 °C for 1 h, 70 °C for 2 h, 80 °C for 11 h, and 90 °C for 9 h. After the reaction was complete, the sample was washed three times alternately with acetone and ultrapure water, and finally dried in a vacuum drying oven at 40 °C for 48 h. The flow chart is shown below. Figure 1 As shown. The final phosphoric acid-functionalized adsorbent SiHmpVa was obtained, with an effective organic matter content of 23.84 wt%, as shown. Figure 2 As shown.

[0027] Example 2 The phosphorylated functionalized adsorbent SiHmpVa prepared in Example 1 was used for the adsorption of scandium in a nitric acid system. The nitric acid concentration varied from 0.00001–6 M, the scandium concentration was 225 ppm, the solid-liquid ratio was 1:200 (g / mL), the adsorption time was 360 min, and the temperature was 25 °C. The phosphorylated functionalized adsorbent SiHmpVa exhibited good adsorption performance for scandium in a 0.00001–5 M HNO3 solution, with an adsorption capacity exceeding 18 mg / g. The results are as follows: Figure 3 As shown. E is the adsorption rate (%), E = (scandium concentration in the solution before adsorption - scandium concentration in the solution after adsorption) / scandium concentration in the solution before adsorption * 100%; Q is the adsorption capacity (mg / g), Q = (scandium concentration in the solution before adsorption - scandium concentration in the solution after adsorption) * solution volume / adsorbent mass.

[0028] Example 3 The phosphorylated functionalized adsorbent SiHmpVa prepared in Example 1 was used for the adsorption of scandium in a hydrochloric acid system. The hydrochloric acid concentration varied from 0.00001–5 M, the scandium concentration was 225 ppm, the solid-liquid ratio was 1:200 (g / mL), the adsorption time was 360 min, and the temperature was 25 °C. The phosphorylated functionalized adsorbent SiHmpVa exhibited good adsorption performance for scandium in 0.00001–5 M HCl solution, with an adsorption capacity exceeding 18 mg / g. The results are as follows: Figure 4 As shown. E is the adsorption rate (%), E = (scandium concentration in the solution before adsorption - scandium concentration in the solution after adsorption) / scandium concentration in the solution before adsorption * 100%; Q is the adsorption capacity (mg / g), Q = (scandium concentration in the solution before adsorption - scandium concentration in the solution after adsorption) * solution volume / adsorbent mass.

[0029] Example 4 The phosphoric acid-functionalized adsorbent SiHmpVa prepared in Example 1 was used for the adsorption of scandium in a sulfuric acid system. The sulfuric acid concentration varied from 0.5 to 4 M, the scandium concentration was 225 ppm, the solid-liquid ratio was 1:200 (g / mL), the adsorption time was 360 min, and the temperature was 25 °C. The phosphoric acid-functionalized adsorbent SiHmpVa exhibited good adsorption performance for scandium in 0.5–4 M H₂SO₄ solution, with an adsorption capacity exceeding 20 mg / g. The results are as follows: Figure 4 As shown. E is the adsorption rate (%), E = (scandium concentration in the solution before adsorption - scandium concentration in the solution after adsorption) / scandium concentration in the solution before adsorption * 100%; Q is the adsorption capacity (mg / g), Q = (scandium concentration in the solution before adsorption - scandium concentration in the solution after adsorption) * solution volume / adsorbent mass.

[0030] Example 5 The phosphorylated functional adsorbent SiHmpVa prepared in Example 1 was used to selectively adsorb scandium in 0.1 M HNO3 solution. The nitric acid concentration was 0.1 M, the scandium concentration was 225 ppm, the other rare earth element concentrations were 5 mM, the solid-liquid ratio was 1:200 (g / mL), the adsorption time was 360 min, and the temperature was 25 °C. The phosphorylated functional adsorbent SiHmpVa exhibited adsorption activity for scandium in 0.1 M HNO3 solution, but almost no adsorption activity for other rare earth elements. The separation coefficient between scandium and other rare earth elements was above 20, indicating that the phosphorylated functional adsorbent SiHmpVa has good adsorption selectivity for scandium. The results are as follows: Figure 6 As shown. Kd is the partition coefficient (mL / g), Kd = (scandium concentration in the solution before adsorption - scandium concentration in the solution after adsorption) * solution volume / scandium concentration in the solution before adsorption / adsorbent mass; SF A / B SF is the separation coefficient between elements A and B. The larger the value deviates from 1, the better the separation performance between the two. A / B=Kd(A) / Kd(B).

[0031] Those skilled in the art should understand that the discussion of any of the above embodiments is merely exemplary and is not intended to imply that the scope of protection of this application is limited to these examples; within the framework of this application, the technical features of the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other variations of different aspects of one or more embodiments of this application as described above, which are not provided in detail for the sake of brevity.

[0032] One or more embodiments in this application are intended to cover all such substitutions, modifications, and variations that fall within the broad scope of this application. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of one or more embodiments in this application should be included within the protection scope of this application.

Claims

1. A sorbent for recovering scandium from an acidic solution, characterized by, The product includes the following raw materials: monomer, crosslinking agent and initiator, wherein the monomer is a mixture of ethylene phosphoric acid and 2-methyl-2-acrylate-2-hydroxyethyl phosphate, wherein the molar ratio of ethylene phosphoric acid and 2-methyl-2-acrylate-2-hydroxyethyl phosphate is 0.1~10:1, and also includes a solvent and a support, wherein the solvent is dimethyl sulfoxide and the support is a porous material; The adsorbent is prepared by introducing a mixture of monomer, crosslinking agent, initiator and solvent into a carrier under negative pressure, heating, reacting and processing to obtain an adsorbent for recovering scandium from an acidic solution; the heating method involves maintaining the temperature at different times for a period of time during the heating process.

2. The adsorbent for recovering scandium from an acidic solution as described in claim 1, characterized in that, The crosslinking agent is ethylene glycol dimethacrylate, and the initiator is azobisisobutyronitrile.

3. The adsorbent for recovering scandium from an acidic solution as described in claim 1 or 2, characterized in that, The weight ratio of the monomer to the crosslinking agent is 0.2~1:0.08~0.4, and the weight ratio of the initiator to the monomer is 0.01~0.05:

1.

4. The adsorbent for recovering scandium from an acidic solution as described in claim 1, characterized in that, The weight ratio of dimethyl sulfoxide to the support is 0.4 to 3:

1.

5. A method for preparing an adsorbent for recovering scandium from an acidic solution as described in any one of claims 1-4, characterized in that, A mixture of monomer, crosslinking agent, initiator and solvent is introduced into a carrier using negative pressure, heated, reacted and processed to obtain an adsorbent for recovering scandium from an acidic solution; the heating method involves maintaining the temperature at different levels for a period of time during the heating process.

6. The preparation method according to claim 5, characterized in that, The heating method involves maintaining the temperature at 55-65℃ for a period of time, then at 65-75℃ for a period of time, then at 75-85℃ for a period of time, and then at 85-95℃ for a period of time.

7. The preparation method according to claim 5, characterized in that, The treatment method involves washing with acetone and ultrapure water alternately, followed by drying.

8. An application of an adsorbent for recovering scandium from an acidic solution as described in any one of claims 1-4, characterized in that, The adsorbent is used to recover scandium.

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