A method for the selective recovery of uranium from a scandium concentrate

Abstract

The present application relates to a kind of method for selectively recovering uranium from scandium concentrate, comprising: using sulfuric acid to carry out leaching treatment to scandium concentrate;Mixing acidic leaching liquid with oxalic acid solution, after the complete precipitation of scandium oxalate solid, obtain the filtrate containing uranium element and a small amount of scandium element as subsequent extraction aqueous phase;Organic extractant is mixed with diluent according to certain proportion to configure organic phase;Mixing organic phase and extraction aqueous phase to obtain load organic phase loaded with uranium and scandium element;Mixing load organic phase with stripping aqueous solution respectively, selectively stripping uranium element, obtain uranium-containing stripping solution.The uranium-scandium separation process of the present application is selective, green and efficient, and the extractant can be recycled, suitable for the collaborative resource recovery of uranium and scandium in complex multi-metal acidic waste liquid, plays a positive role in the comprehensive recovery and utilization of uranium element in scandium concentrate, the recovery rate of uranium element reaches 98.6%, and the separation coefficient of uranium element and scandium element reaches 3504.

Description

Technical Field

[0001] This application belongs to the field of hydrometallurgical recovery technology, specifically relating to a method for selectively recovering uranium from scandium concentrate. Background Technology

[0002] Against the backdrop of a global shift towards clean energy and advanced materials, the strategic importance of key metals is becoming increasingly prominent. In 2020, global nickel production totaled 2.4307 million tons; of which 69% (1.6777 million tons) came from laterite nickel ore. As the main source of global nickel resources, laterite nickel ore also contains various high-value key metals (such as 20-50 ppm of the rare metal scandium Sc and trace amounts of uranium).

[0003] To meet the requirements of green mining, wet recovery technology is usually used when processing laterite nickel ore with a nickel content of less than 0.8%. During this recovery process, scandium concentrate enriched with key metals such as scandium and uranium is generated. Due to the huge amount of laterite nickel ore, the total amount of uranium in scandium concentrate is also a significant part.

[0004] However, research on how to selectively separate and recover the key metal uranium from scandium concentrate remains largely unexplored. Although early studies, such as those by Lash and Ross in 1961, successfully separated uranium and scandium from uranium ore leachate, these methods heavily relied on highly toxic hydrofluoric acid (HF) for precipitation. These methods were cumbersome and posed significant safety and environmental risks, failing to meet modern green chemistry principles. Furthermore, the fundamental differences in their solution chemistry made it difficult to directly apply existing separation strategies.

[0005] Therefore, developing a highly efficient, environmentally friendly, and industrially scalable selective uranium / scandium (U / Sc) separation technology for the specific system of scandium concentrate acidic leaching solution is of great practical significance. Summary of the Invention

[0006] The purpose of this application is to overcome the shortcomings of the prior art and provide a method for selectively recovering uranium from scandium concentrate, selectively separating uranium from scandium concentrate to achieve efficient separation of uranium and scandium in scandium concentrate and recovery of uranium.

[0007] The technical problem solved by this application is achieved through the following technical solution: A method for selectively recovering uranium from scandium concentrate, the method comprising the following steps: S1. Saturated sulfuric acid is used to leach scandium concentrate to obtain an acidic leachate; S2. Mix the acidic leachate with the oxalic acid solution. After the scandium oxalate solid has completely precipitated, a filtrate containing uranium and a small amount of scandium is obtained, which is used as the aqueous phase for subsequent extraction. S3. Prepare an organic phase by mixing the organic extractant with the diluent in a certain proportion; S4. Mix the above organic phase with the extraction aqueous phase and shake thoroughly to obtain a loaded organic phase containing uranium and scandium. S5. After mixing the above-mentioned loaded organic phase with the back-extraction aqueous solution and shaking thoroughly, selective back-extraction of uranium is performed to obtain uranium-containing back-extraction solution.

[0008] Furthermore, the sulfuric acid concentration of S1 is 10% to 30%, preferably 15%.

[0009] Furthermore, the oxalic acid concentration of S2 is 5%~15%, preferably 10%; the uranium ion concentration of the acidic leachate is 0.5~0.8 g / L, preferably 0.69 g / L; the scandium ion concentration of the acidic leachate is 0.1~0.2 g / L, preferably 0.15 g / L; and the pH of the extraction aqueous phase is 0.1~5, preferably 0.3.

[0010] Furthermore, the diluent for S3 is sulfonated kerosene, carbon tetrachloride, toluene, chlorobenzene, or chloroform.

[0011] Furthermore, the organic extractant of S3 is any one of bis(2,4,4-trimethylpentyl)phosphonic acid, tributyl phosphate, di(2-ethylhexyl) phosphate, 2-ethylhexylphosphonic acid mono(2-ethylhexyl) ester, and compound I, wherein the structure of compound I is: .

[0012] Furthermore, the weight ratio of the diluent to the organic extractant in S3 is 1~500:1~50, preferably 4:1.

[0013] Furthermore, in S4, the mass ratio of the aqueous phase to the organic phase is 1:9 to 9:1, the stirring time is 1 to 100 min, the stirring temperature is 25 to 50 °C, and the number of extraction stages is 1 to 5.

[0014] Furthermore, the stripping agent aqueous solution of S5 is any one of hydrochloric acid aqueous solution, nitric acid aqueous solution, oxalic acid aqueous solution, ammonia water, sodium hydroxide aqueous solution, sodium carbonate aqueous solution and ammonium carbonate aqueous solution, and the concentration of the stripping agent aqueous solution is 5~25%.

[0015] Furthermore, the mass ratio of the back-extraction aqueous solution to the supported organic phase in S5 is 1:9 to 9:1, the shaking and stirring time is 1 to 100 min, the stirring temperature is 25 to 50℃, and the number of back-extraction stages is 1 to 5.

[0016] Compared with the prior art, the present invention has the following beneficial effects: 1. The present invention relates to a process for recovering uranium from scandium concentrate. This process selectively recovers uranium from scandium concentrate through a two-step separation of leaching precipitation and solvent extraction. The two elements can be selectively extracted and separated in an acidic solution of sulfuric acid-oxalic acid system. This extraction process has strong separation ability of uranium and scandium and has a high recovery rate.

[0017] 2. The extractant used in this invention can be reused after the back-extraction step without causing secondary pollution, effectively extending the life of the extractant.

[0018] 3. This invention does not require the use of hazardous chemicals such as hydrofluoric acid for precipitation treatment, making it more environmentally friendly.

[0019] 4. The separation process used in this invention has good selectivity for uranium and scandium, is green and efficient, and the extractant can be recycled. It is suitable for the synergistic resource recovery of uranium and scandium in complex polymetallic acidic waste liquids, and plays a positive role in the comprehensive recovery and utilization of uranium in scandium concentrate. The uranium recovery rate reaches 98.6%, and the separation coefficient between uranium and scandium reaches 3504. Detailed Implementation

[0020] The present application will be further described in detail below through specific embodiments. The following embodiments are merely descriptive and not limiting, and should not be used to limit the scope of protection of the present application.

[0021] An innovative method for selectively recovering uranium from scandium concentrate, characterized by the following testing method: The original extract, raffinate, and back-extract were all diluted 1000-fold to prepare the sample for analysis. The diluted aqueous metal ions were detected by ICP-MS (Inductively Coupled Plasma Mass Spectrometry). ICP-MS consists of an ICP torch, a mass spectrometer, and an interface device, and primarily relies on the mass spectrometer for analytical calculations. The ICP torch generates high-temperature plasma, using a high-voltage spark to ionize the gas and a high-frequency electric field to generate a plasma flow. Driven by the gas, a stable plasma torch is formed at the nozzle. The sample is atomized within the system to form an aerosol, which is carried by a carrier gas into the central region of the torch. The aerosol is subsequently evaporated, decomposed, excited, and ionized to produce ions. The interface, consisting of a sampling cone and a cutoff cone, transmits the ions to the mass spectrometer, which separates the charged ions according to their mass-to-charge ratio (m / z), thereby analyzing and calculating the elemental intensity.

[0022] Analysis was performed using an ICAP RQ inductively coupled plasma mass spectrometer (ICP-MS) manufactured by Thermo Fisher Scientific.

[0023] Data processing: Extraction rate ( E Extraction rate is used to represent the completeness of the extraction of the extracted substance from the aqueous phase to the organic phase, which is the ratio of the content of the extracted substance in the organic phase to the content in the initial aqueous phase. It can be obtained directly by measurement and can directly reflect the extraction effect. It is calculated by formula (1).

[0024] (1) in: E Extraction rate, % C o The initial elemental concentration in the aqueous phase before extraction is in mg / L. C e The concentration of elements in the aqueous phase after extraction is in mg / L.

[0025] Distribution ratio (D): When separating and purifying substances by solvent extraction, it is used to indicate the ease with which a substance is extracted and separated. It is obtained by analyzing the distribution relationship between the extracted substances in the two phases, that is, the ratio of the concentration of the extracted substance in the organic phase to its concentration in the aqueous phase, and is calculated by formula (2).

[0026] (2) in: D For allocation ratio; C o The initial elemental concentration in the aqueous phase before extraction is in mg / L. C e The concentration of elements in the aqueous phase after extraction is in mg / L; V aq Let L be the volume of the aqueous phase in the extraction system; V org Let L be the volume of the organic phase in the extraction system.

[0027] Back-extraction rate ( S ): When back-extracting the target substance from the loaded organic phase, it is used to indicate the completeness of the target substance being back-extracted into the aqueous phase, which is the ratio of the content of the loaded organic phase substance to the content of the aqueous phase substance after back-extraction, calculated by formula (3).

[0028] (3) in: S The back-extraction rate is %; M aq The content of substances in the aqueous phase after back-extraction is in mg; M org The content of the loaded organic phase material is expressed in mg.

[0029] Separation coefficient ( βIf there are other components in the extraction system besides the substances that need to be extracted and separated, the separation coefficient can be used to measure the ease with which they can be separated by extraction. The larger the value, the easier it is for the two to be extracted and separated. It is the ratio of the distribution ratio of the two substances to be separated, and is calculated by formula (4).

[0030] (4) in: The separation coefficient between uranium and scandium; The allocation ratio of uranium; The allocation ratio for scandium.

[0031] Example 1 (1) 1 g of scandium concentrate was stirred with 10 mL of sulfuric acid solution (15% sulfuric acid) at 120 °C for 4 h to obtain a leaching solution containing uranium and scandium.

[0032] (2) Mix the above leachate with 10 mL of oxalic acid solution (10% oxalic acid) and let it stand for 24 hours to allow precipitation. After filtration, dilute to 20 mL in a volumetric flask and adjust the pH of the solution with 10 M sodium hydroxide solution to obtain a filtrate with pH=0.3.

[0033] (3) 16g of sulfonated kerosene and 4g of compound I were thoroughly mixed to obtain an organic phase.

[0034] (4) Take 20 g of the above-mentioned filtrate after volume adjustment as the aqueous phase and mix it with 20 g of the organic phase. The stirring temperature is 25℃. An organic phase rich in most of the uranium and scandium elements in the pre-extraction liquid can be obtained. After extraction equilibrium, the uranium extraction rate is 96.48% and the scandium extraction rate is 96.69%.

[0035] (5) Mix 20g of the loaded organic phase and 20g of 10% ammonium carbonate aqueous solution for back-extraction and stir at a stirring temperature of 25℃. After back-extraction equilibrium, the back-extraction rate of uranium can reach 98.6%, while the back-extraction rate of scandium is only 1.97%. The separation coefficient between uranium and scandium is 3504.

[0036] Example 2 (1) 1 g of scandium concentrate was stirred with 10 mL of sulfuric acid solution (15% sulfuric acid) at 120 °C for 4 h to obtain a leaching solution containing uranium and scandium.

[0037] (2) Mix the above leachate with 10 mL of oxalic acid solution (10% oxalic acid) and let it stand for 24 hours to wait for precipitation. After filtration, dilute to 20 mL in a volumetric flask and adjust the pH of the solution with 10 M sodium hydroxide solution to obtain a filtrate with pH=1.

[0038] (3) 16g of sulfonated kerosene and 4g of compound I were thoroughly mixed to obtain an organic phase.

[0039] (4) Take 20 g of the above-mentioned filtrate after volume adjustment as the aqueous phase and mix it with 20 g of the organic phase. The stirring temperature is 25℃. An organic phase rich in most of the uranium and scandium elements in the pre-extraction liquid can be obtained. After extraction equilibrium, the uranium extraction rate is 91.44% and the scandium extraction rate is 95.72%.

[0040] (5) Mix 20g of the loaded organic phase and 20g of 10% ammonium carbonate aqueous solution for back-extraction. Stir at 25°C. After back-extraction equilibrium, the back-extraction rate of uranium can reach 90.54%, while the back-extraction rate of scandium is only 3.42%. The separation coefficient between uranium and scandium is 270.

[0041] Example 3 (1) 1 g of scandium concentrate was stirred with 10 mL of sulfuric acid solution (15% sulfuric acid) at 120 °C for 4 h to obtain a leaching solution containing uranium and scandium.

[0042] (2) Mix the above leachate with 10 mL of oxalic acid solution (10% oxalic acid) and let it stand for 24 hours to allow precipitation. After filtration, dilute to 20 mL in a volumetric flask and adjust the pH of the solution with 10 M sodium hydroxide solution to obtain a filtrate with pH=0.3.

[0043] (3) 16g of sulfonated kerosene and 4g of compound I were thoroughly mixed to obtain an organic phase.

[0044] (4) Take 20 g of the above-mentioned filtrate after volume adjustment as the aqueous phase and mix it with 20 g of the organic phase. The stirring temperature is 25℃. An organic phase rich in most of the uranium and scandium elements in the pre-extraction liquid can be obtained. After extraction equilibrium, the uranium extraction rate is 96.48% and the scandium extraction rate is 96.69%.

[0045] (5) Mix 20g of the loaded organic phase and 10g of 10% ammonium carbonate aqueous solution for back-extraction and stir at a stirring temperature of 25℃. After back-extraction equilibrium, the back-extraction rate of uranium can reach 46%, while the back-extraction rate of scandium is only 1.02%. The separation coefficient between uranium and scandium is 82.

[0046] Example 4 (1) 1 g of scandium concentrate was stirred with 10 mL of sulfuric acid solution (15% sulfuric acid) at 120 °C for 4 h to obtain a leaching solution containing uranium and scandium.

[0047] (2) Mix the above leachate with 10 mL of oxalic acid solution (10% oxalic acid) and let it stand for 24 hours to allow precipitation. After filtration, dilute to 20 mL in a volumetric flask and adjust the pH of the solution with 10 M sodium hydroxide solution to obtain a filtrate with pH=0.3.

[0048] (3) 16g of sulfonated kerosene and 4g of compound I were thoroughly mixed to obtain an organic phase.

[0049] (4) Take 20 g of the above-mentioned filtrate after volume adjustment as the aqueous phase and mix it with 20 g of the organic phase. The stirring temperature is 25℃. An organic phase rich in most of the uranium and scandium elements in the pre-extraction liquid can be obtained. After extraction equilibrium, the uranium extraction rate is 96.48% and the scandium extraction rate is 96.69%.

[0050] (5) Mix 20g of the loaded organic phase and 20g of 5% ammonium carbonate aqueous solution for back-extraction and stir at a stirring temperature of 25℃. After back-extraction equilibrium, the back-extraction rate of uranium can reach 84.65%, while the back-extraction rate of scandium is only 1.13%. The separation coefficient between uranium and scandium is 482.

[0051] Example 5 (1) 1 g of scandium concentrate was stirred with 10 mL of sulfuric acid solution (15% sulfuric acid) at 120 °C for 4 h to obtain a leaching solution containing uranium and scandium.

[0052] (2) Mix the above leachate with 10 mL of oxalic acid solution (10% oxalic acid) and let it stand for 24 hours to allow precipitation. After filtration, dilute to 20 mL in a volumetric flask and adjust the pH of the solution with 10 M sodium hydroxide solution to obtain a filtrate with pH=0.3.

[0053] (3) 16g of sulfonated kerosene and 4g of compound I were thoroughly mixed to obtain an organic phase.

[0054] (4) Take 20 g of the above-mentioned filtrate after volume adjustment as the aqueous phase and mix it with 20 g of the organic phase. The stirring temperature is 25℃. An organic phase rich in most of the uranium and scandium elements in the pre-extraction liquid can be obtained. After extraction equilibrium, the uranium extraction rate is 96.48% and the scandium extraction rate is 96.69%.

[0055] (5) Mix 20g of the loaded organic phase and 20g of 15% ammonium carbonate aqueous solution for back-extraction and stir at a stirring temperature of 25℃. After back-extraction equilibrium, the back-extraction rate of uranium can reach 99.71%, and the back-extraction rate of scandium is 43.94%. The separation coefficient between uranium and scandium is 438.

[0056] Example 6 (1) 1 g of scandium concentrate was stirred with 10 mL of sulfuric acid solution (15% sulfuric acid) at 120 °C for 4 h to obtain a leaching solution containing uranium and scandium.

[0057] (2) Mix the above leachate with 10 mL of oxalic acid solution (10% oxalic acid) and let it stand for 24 hours to allow precipitation. After filtration, dilute to 20 mL in a volumetric flask and adjust the pH of the solution with 10 M sodium hydroxide solution to obtain a filtrate with pH=0.3.

[0058] (3) 16g of sulfonated kerosene and 4g of 2-ethylhexylphosphonic acid mono(2-ethylhexyl) ester were thoroughly mixed to obtain an organic phase.

[0059] (4) Take 20 g of the above-mentioned filtrate after volume adjustment as the aqueous phase, mix it with 20 g of the organic phase and stir at a stirring temperature of 25°C. An organic phase containing some uranium and scandium can be obtained. After extraction equilibrium, the extraction rate of uranium is 17.99% and the extraction rate of scandium is 11.31%.

[0060] (5) Mix 20g of the loaded organic phase and 20g of 10% ammonium carbonate aqueous solution for back-extraction and stir at a stirring temperature of 25℃. After back-extraction equilibrium, the back-extraction rate of uranium can reach 89.4%, while the back-extraction rate of scandium is only 5.11%. The separation coefficient between uranium and scandium is 167.

[0061] Example 7 (1) 1 g of scandium concentrate was stirred with 10 mL of sulfuric acid solution (15% sulfuric acid) at 120 °C for 4 h to obtain a leaching solution containing uranium and scandium.

[0062] (2) Mix the above leachate with 10 mL of oxalic acid solution (10% oxalic acid) and let it stand for 24 hours to allow precipitation. After filtration, dilute to 20 mL in a volumetric flask and adjust the pH of the solution with 10 M sodium hydroxide solution to obtain a filtrate with pH=0.3.

[0063] (3) 16g of sulfonated kerosene and 4g of bis(2,4,4-trimethylpentyl)phosphonic acid were thoroughly mixed to obtain an organic phase.

[0064] (4) Take 20 g of the above-mentioned filtrate after volume adjustment as the aqueous phase and mix it with 20 g of the organic phase. Stir at 25°C to obtain an organic phase rich in most of the uranium and scandium elements in the pre-extraction liquid. After extraction equilibrium, the uranium extraction rate is 90.12% and the scandium extraction rate is 89.26%.

[0065] (5) Mix 20g of the loaded organic phase and 20g of 10% ammonium carbonate aqueous solution for back-extraction and stir at a stirring temperature of 25℃. After back-extraction equilibrium, the back-extraction rate of uranium can reach 96.16%, while the back-extraction rate of scandium is only 2.95%. The separation coefficient between uranium and scandium is 2609.

[0066] Example 8 (1) 1 g of scandium concentrate was stirred with 10 mL of sulfuric acid solution (15% sulfuric acid) at 120 °C for 4 h to obtain a leaching solution containing uranium and scandium.

[0067] (2) Mix the above leachate with 10 mL of oxalic acid solution (10% oxalic acid) and let it stand for 24 hours to allow precipitation. After filtration, dilute to 20 mL in a volumetric flask and adjust the pH of the solution with 10 M sodium hydroxide solution to obtain a filtrate with pH=0.3.

[0068] (3) 16g of sulfonated kerosene and 4g of compound I were thoroughly mixed to obtain an organic phase.

[0069] (4) Take 20 g of the above-mentioned filtrate after volume adjustment as the aqueous phase and mix it with 20 g of the organic phase. The stirring temperature is 25℃. An organic phase rich in most of the uranium and scandium elements in the pre-extraction liquid can be obtained. After extraction equilibrium, the uranium extraction rate is 96.48% and the scandium extraction rate is 96.69%.

[0070] (5) Mix 20g of the loaded organic phase and 20g of 20% hydrochloric acid aqueous solution for back-extraction. Stir at 25°C. After back-extraction equilibrium, the back-extraction rate of uranium is only 0.52%, while the back-extraction rate of scandium can reach 10.38%. The separation coefficient between uranium and scandium is 186.

[0071] Example 9 (1) 1 g of scandium concentrate was stirred with 10 mL of sulfuric acid solution (15% sulfuric acid) at 120 °C for 4 h to obtain a leaching solution containing uranium and scandium.

[0072] (2) Mix the above leachate with 10 mL of oxalic acid solution (10% oxalic acid) and let it stand for 24 hours to allow precipitation. After filtration, dilute to 20 mL in a volumetric flask and adjust the pH of the solution with 10 M sodium hydroxide solution to obtain a filtrate with pH=0.3.

[0073] (3) 16g of sulfonated kerosene and 4g of compound I were thoroughly mixed to obtain an organic phase.

[0074] (4) Take 20 g of the above-mentioned filtrate after volume adjustment as the aqueous phase and mix it with 20 g of the organic phase. The stirring temperature is 25℃. An organic phase rich in most of the uranium and scandium elements in the pre-extraction liquid can be obtained. After extraction equilibrium, the uranium extraction rate is 96.48% and the scandium extraction rate is 96.69%.

[0075] (5) Mix 20g of the loaded organic phase and 20g of 15% sodium hydroxide aqueous solution for back-extraction. Stir at 25°C. After back-extraction equilibrium, the back-extraction rate of uranium can reach 78.48%, and the back-extraction rate of scandium can reach 80.16%. The separation coefficient of uranium and scandium is 73.

[0076] Example 10 (1) 1 g of scandium concentrate was stirred with 10 mL of sulfuric acid solution (15% sulfuric acid) at 120 °C for 4 h to obtain a leaching solution containing uranium and scandium.

[0077] (2) Mix the above leachate with 10 mL of oxalic acid solution (10% oxalic acid) and let it stand for 24 hours to allow precipitation. After filtration, dilute to 20 mL in a volumetric flask and adjust the pH of the solution with 10 M sodium hydroxide solution to obtain a filtrate with pH=0.3.

[0078] (3) 16g of sulfonated kerosene and 4g of compound I were thoroughly mixed to obtain an organic phase.

[0079] (4) Take 20 g of the above-mentioned filtrate after volume adjustment as the aqueous phase and mix it with 20 g of the organic phase. The stirring temperature is 25℃. An organic phase rich in most of the uranium and scandium elements in the pre-extraction liquid can be obtained. After extraction equilibrium, the uranium extraction rate is 96.48% and the scandium extraction rate is 96.69%.

[0080] (5) Mix 20g of the loaded organic phase and 20g of 15% sodium carbonate aqueous solution for back-extraction and stir at a stirring temperature of 25℃. After back-extraction equilibrium, the back-extraction rate of uranium can reach 11.03% and the back-extraction rate of scandium can reach 21.45%. The separation coefficient of uranium and scandium is 190.

Claims

1. A method for selectively recovering uranium from scandium concentrate, characterized in that: The steps of the method are as follows: S1. Saturated sulfuric acid is used to leach scandium concentrate to obtain an acidic leachate; S2. Mix the acidic leachate with the oxalic acid solution. After the scandium oxalate solid has completely precipitated, a filtrate containing uranium and a small amount of scandium is obtained, which is used as the aqueous phase for subsequent extraction. S3. Prepare an organic phase by mixing the organic extractant with the diluent in a certain proportion; S4. Mix the above organic phase with the extraction aqueous phase and shake thoroughly to obtain a loaded organic phase containing uranium and scandium. S5. After mixing the above-mentioned loaded organic phase with the back-extraction aqueous solution and shaking thoroughly, selective back-extraction of uranium is performed to obtain uranium-containing back-extraction solution.

2. The method for selectively recovering uranium from scandium concentrate according to claim 1, characterized in that: The sulfuric acid concentration of S1 is 10% to 30%, preferably 15%.

3. The method for selectively recovering uranium from scandium concentrate according to claim 1, characterized in that: The oxalic acid concentration of S2 is 5%~15%, preferably 10%; the uranium ion concentration of the acidic leachate is 0.5~0.8 g / L, preferably 0.69 g / L; the scandium ion concentration of the acidic leachate is 0.1~0.2 g / L, preferably 0.15 g / L; and the pH of the extraction aqueous phase is 0.1~5, preferably 0.

3.

4. The method for selectively recovering uranium from scandium concentrate according to claim 1, characterized in that: The diluent for S3 is sulfonated kerosene, carbon tetrachloride, toluene, chlorobenzene, or chloroform.

5. The method for selectively recovering uranium from scandium concentrate according to claim 1, characterized in that: The organic extractant of S3 is any one of bis(2,4,4-trimethylpentyl)phosphonic acid, tributyl phosphate, di(2-ethylhexyl) phosphate, 2-ethylhexylphosphonic acid mono(2-ethylhexyl) ester, and compound I, wherein the structure of compound I is: 。 6. The method for selectively recovering uranium from scandium concentrate according to claim 1, characterized in that: The weight ratio of the diluent to the organic extractant in S3 is 1~500:1~50, preferably 4:

1.

7. The method for selectively recovering uranium from scandium concentrate according to claim 1, characterized in that: In S4, the mass ratio of the aqueous phase to the organic phase is 1:9 to 9:1, the stirring time is 1 to 100 min, the stirring temperature is 25 to 50℃, and the number of extraction stages is 1 to 5.

8. The method for selectively recovering uranium from scandium concentrate according to claim 1, characterized in that: The stripping agent aqueous solution of S5 is any one of hydrochloric acid aqueous solution, nitric acid aqueous solution, oxalic acid aqueous solution, ammonia water, sodium hydroxide aqueous solution, sodium carbonate aqueous solution and ammonium carbonate aqueous solution, and the concentration of the stripping agent aqueous solution is 5~25%.

9. The method for selectively recovering uranium from scandium concentrate according to claim 1, characterized in that: The mass ratio of the back-extraction aqueous solution to the supported organic phase in S5 is 1:9 to 9:1, the shaking and stirring time is 1 to 100 min, the stirring temperature is 25 to 50℃, and the number of back-extraction stages is 1 to 5.

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