Method for selectively extracting scandium from nickel laterite ore pickle liquor with iron and aluminum removed

Abstract

The invention discloses a method for selectively extracting scandium from nickel laterite ore pickle liquor with iron and aluminum removed. The scandium extraction method comprises the following steps: adjusting the pH value of the nickel laterite ore pickle liquor from which iron and aluminum are removed to 0.5-2, and adding an extraction agent for extraction to obtain a first organic phase and a first water phase; performing first countercurrent washing on the first organic phase by using a first detergent to obtain a second organic phase and a second water phase; performing second countercurrent washing on the second organic phase by using a second detergent to obtain a third organic phase and a third water phase; performing countercurrent reverse extraction on the third organic phase by adopting a reverse extraction agent to obtain a fourth organic phase and a fourth water phase; and reacting a precipitant with the fourth water phase to generate a precipitate, and roasting the precipitate to obtain scandium oxide. According to the method, a foundation is laid for preparation of high-purity scandium oxide, the resource utilization rate of the laterite-nickel ore is remarkably increased, and the raw material cost is reduced.

Description

Technical Field

[0001] The present invention belongs to the technical field of hydrometallurgy, and particularly relates to a method for selectively extracting scandium from the acid leaching solution of laterite nickel ore after removing iron and aluminum. Background Art

[0002] Scandium is often accompanied by a small amount in laterite nickel ore. In the production process of nickel cobalt hydroxide in hydrometallurgy, as the pH value of the iron and aluminum removal process increases, scandium will co-precipitate with iron and aluminum into the slag phase, resulting in a large amount of nickel cobalt precipitation and thus reducing the recovery rate of nickel cobalt. However, due to the low content of scandium in the iron and aluminum slag, and problems such as low recovery rate and high cost, scandium is usually not processed. In addition, these slag materials contain a high proportion of impurities such as iron, aluminum, manganese, magnesium, calcium, etc., and their contents far exceed that of scandium, which is likely to interfere with the extraction of scandium and thus affect the synthesis of subsequent high-purity scandium oxide.

[0003] In view of the above problems, a variety of treatment methods have been proposed at present. For example, CN 116024443A discloses a method for extracting and recovering scandium, using P204 and trioctylamine (N235) as extractants to extract and recover scandium from the red mud leaching solution. However, in the stripping process of this method, strong alkali is required to elute scandium from the organic phase, resulting in a large consumption of acid and alkali and being prone to generating a third phase. CN 117701920A discloses a method for extracting and recovering scandium, using secondary amine extractants to recover scandium from laterite nickel ore. This method has a high selectivity for scandium, and scandium can be stripped by weak acid or weak base, and it is not easy to emulsify or generate a third phase. However, associated elements of scandium such as Th, Ti, U, Zr, etc. are difficult to effectively remove, and may enter the final product scandium oxide following subsequent processes, resulting in the impurity content being difficult to meet the national standard requirements. CN104498714B discloses a method for separating impurities such as Fe, Al, Ca, Ti, etc. from a scandium-containing solution. This method obtains a purified scandium solution by reducing, complexing and adjusting the pH of the scandium-containing solution, and then mixing it with a strongly acidic cation exchange resin or flowing it through an exchange column filled with this resin. The impurity removal process of this process is relatively complex, with high costs, and the adsorption and desorption cycle of the resin is long, and the overall treatment efficiency is low. CN 106395881 B discloses a method for removing zirconium, hafnium, calcium from crude scandium oxide to synthesize high-purity scandium oxide. This method requires dissolving the crude scandium oxide first, then adding ammonium o-iodobenzoate and boiling to precipitate and separate the impurities; finally, high-purity scandium oxide is obtained through the steps of oxalic acid precipitation and calcination.

[0004] In summary, in view of the limitations of the existing technology, it is urgent to develop a more efficient, environmentally friendly and economical method for extracting and purifying scandium to improve the utilization rate of laterite nickel ore and reduce the raw material cost. Summary of the Invention

[0005] Aiming at the deficiencies of the prior art, the purpose of the present invention is to provide a method for selectively extracting scandium from the acid leaching solution of laterite nickel ore after iron and aluminum removal, aiming to solve the technical problems of long process flow, low treatment efficiency and high material cost existing in the prior art during the extraction of scandium.

[0006] The purpose of the present invention is achieved through the following technical solutions: A method for selectively extracting scandium from the acid leaching solution of laterite nickel ore after iron and aluminum removal, comprising the following steps: S1. Adjust the pH of the acid leaching solution of laterite nickel ore after iron and aluminum removal to 0.5 - 2, add an extractant for extraction to obtain a first organic phase and a first aqueous phase; The main reactions involved are: RNH2 + H2SO4 → (RNH3)HSO4, where RNH2 represents the extractant; 3(RNH3)HSO4 + Sc 3+ + SO4 2- → (RNH3)3Sc(SO4)3 + HSO4 - . S2. Use a first detergent to perform a first countercurrent washing on the first organic phase to obtain a second organic phase and a second aqueous phase; The main reactions involved are: (RNH3)3Sc(SO4)3 + (RNH3) n / n-1 M(SO4) n + H + + H2O2 + SO4 2- → (RNH3)3Sc(SO4)3 + [TiO(H2O2)] 2+ + CoSO4 + NiSO4 + ZrSO4 + CuSO4 + (RNH3)HSO4, where M is impurity elements such as Co, Ni, Zr, Cu, Ti, etc.

[0007] S3. Use a second detergent to perform a second countercurrent washing on the second organic phase to obtain a third organic phase and a third aqueous phase; The main reactions involved are: 2(RNH3)3UO(SO4)3 + (RNH3)Th(SO4)3 + OH - + 3CO3 2- → 3RNH2 + SO4 2- + 8H2O + 2UO2(CO3)3 4- + Th(CO3)3 2- .

[0008] S4. Use a stripping agent to perform a countercurrent stripping on the third organic phase to obtain a fourth organic phase and a fourth aqueous phase; S5. React the precipitant with the fourth aqueous phase to form a precipitate, and calcine the precipitate to obtain scandium oxide.

[0009] Preferably, after step S4, the fourth organic phase is recycled as an extractant to step S1.

[0010] Preferably, in step S1, the pH is adjusted by adding concentrated sulfuric acid.

[0011] Preferably, the extractant in step S1 is composed of a scandium extractant, an organic alcohol, and a diluent mixed in a volume ratio of 20% - 30%: 5% - 15%: 55% - 75%.

[0012] Preferably, the scandium extractant is a secondary carbon primary amine extractant N - 1923.

[0013] Preferably, the organic alcohol is at least one of isooctanol and sec - octanol.

[0014] Preferably, the diluent is at least one of solvent oil No. 260 and dodecane.

[0015] Preferably, the specific extraction method in step S1 is counter - current extraction. The extraction stage of counter - current extraction is 1 - 3, and the feed flow ratio of the extractant to the material to be extracted is 1:4 - 8.

[0016] Preferably, the first counter - current washing in step S2 is 1 - 3 - stage washing, and the feed flow ratio of the first organic phase to the first detergent is 0.5 - 5:1.

[0017] Preferably, the first detergent in step S2 includes a mixed solution of sulfuric acid solution and hydrogen peroxide. The concentration of the sulfuric acid solution is 0.5 - 3 M, the concentration of the hydrogen peroxide is 1% - 5%, and the volume ratio of the sulfuric acid solution to the hydrogen peroxide is 10:0.25 - 1.25.

[0018] Preferably, the second counter - current washing in step S3 is 1 - 3 - stage washing, and the feed flow ratio of the second organic phase to the second detergent is 0.5 - 5:1.

[0019] Preferably, the second detergent in step S3 is a carbonate / bicarbonate - alkaline solution mixed system. Among them, the concentration of carbonate / bicarbonate is 0.3 - 1.2 M; for the alkaline solution system, liquid alkali or ammonia water is used, and its OH - concentration is 0.25 - 1.5 M.

[0020] Preferably, the counter - current stripping in step S4 is 1 - 3 - stage stripping, and the feed flow ratio of the third organic phase to the stripping agent is 2 - 8:1.

[0021] ​

[0022] Preferably, the stripping agent is hydrochloric acid with a concentration of 2 - 5 M.

[0023] Preferably, the molar ratio of the precipitating agent to scandium in the fourth aqueous phase in step S5 is 1.5 - 3:1.

[0024] Preferably, the precipitating agent and the fourth aqueous phase in step S5 react at 60 - 80 °C for 2 - 5 h to form a precipitate.

[0025] Preferably, the temperature of the roasting treatment in step S5 is 650 - 850 °C and the time is 2 - 4 h.

[0026] Compared with the prior art, the beneficial effects of the present invention include: The present invention focuses on solving the technical problem of efficiently extracting scandium from the acid leaching solution of laterite nickel ore after removing iron and aluminum and achieving its deep separation from impurities. By optimizing the extraction system and separation process, it lays a foundation for the subsequent preparation of high-purity scandium oxide. This technology can improve the resource utilization rate of laterite nickel ore, reduce raw material costs, and at the same time provide an innovative method for the targeted recovery of scandium elements and the co-removal of impurities in complex systems. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a process flow diagram of the method for selectively extracting scandium from the acid leaching solution of laterite nickel ore after removing iron and aluminum of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0028] In order to make the objectives, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0029] Example 1 A method for selectively extracting scandium from the acid leaching solution of laterite nickel ore after removing iron and aluminum, the specific steps are as follows: S1. Take the acid leaching solution of laterite nickel ore after removing iron and aluminum, and the main component composition of the acid leaching solution of laterite nickel ore after removing iron and aluminum is shown in Table 1.

[0030] Table 1 Composition of the acid leaching solution (mg / L)

[0031] By adding concentrated sulfuric acid to adjust the pH of the above-mentioned acid leaching solution of laterite nickel ore after removing iron and aluminum to 1, adding an extractant for 2-stage countercurrent extraction, and the feed flow ratio of the extractant to the material to be extracted is 1:6, to obtain a first organic phase and a first aqueous phase; the extractant is composed of N1923, isooctanol and n-dodecane mixed in a volume ratio of 25%:10%:65%. The first organic phase contains scandium.

[0032] S2. Use a mixed solution of sulfuric acid solution and hydrogen peroxide as the first detergent. The concentration of the sulfuric acid solution is 1.5 M, the concentration of the hydrogen peroxide is 2.5%, and the volume ratio of the sulfuric acid solution to the hydrogen peroxide is 10:1. Perform 2-stage first countercurrent washing on the first organic phase with the first detergent, and the feed flow rate ratio of the first organic phase to the first detergent is 4:1 to obtain a second organic phase and a second aqueous phase; the second organic phase contains scandium. After testing and calculation, the washing rates (stripping rates) of scandium, cobalt, nickel, aluminum, iron, and zirconium are 1.26%, 98.33%, 99.52%, 97.85%, 71.11%, and 98.38% respectively. The difficult-to-wash accompanying element Ti forms [TiO(H2O2)] through complex washing with hydrogen peroxide 2+ , and the removal rate reaches 99%.

[0033] S3. For difficult-to-wash accompanying elements such as uranium and thorium, perform 2-stage second countercurrent washing on the second organic phase with the second detergent: Wash again with a mixed solution of 1 M sodium carbonate solution + 0.5 M ammonia water. The feed flow rate ratio of the second organic phase to the second detergent is 2:1 each time to obtain a third organic phase and a third aqueous phase; the third organic phase contains scandium. After testing and calculation, the washing rates of uranium and thorium are 93% and 88% respectively. During this washing process, by forming UO2(CO3)3 4- , Th(CO3)3 2- complexes, the effective separation of scandium from uranium and thorium can be further achieved. In addition, the washing rates of other conventional impurity elements are also relatively high, so the effective separation of scandium from these impurities can be realized.

[0034] S4. Use 3 M hydrochloric acid as the stripping agent to perform 3-stage countercurrent stripping on the third organic phase. The feed flow rate ratio of the third organic phase to the stripping agent is 6:1 to obtain a fourth organic phase and a fourth aqueous phase; the fourth aqueous phase contains scandium. After testing and calculation, the stripping rate of scandium is 99.08%, while the stripping rates of the remaining impurity elements are all less than 1%. Therefore, this method can achieve the selective extraction of scandium and effectively separate impurities that meet national standards.

[0035] S5. Use oxalic acid as the precipitant, and the molar ratio of the precipitant to scandium in the fourth aqueous phase is 2:1. React the precipitant and the fourth aqueous phase at 70 °C for 2 h to form scandium oxalate precipitate, and perform calcination treatment on this precipitate at 700 °C for 3 h to obtain scandium oxide. After testing, the purity of the scandium oxide reaches 99.9%, meeting the requirements for the impurity content of the Sc2O3-3N level in GB-T 13219-2018.

[0036] Comparative Example 1 A method for selectively extracting scandium from a red mud nickel ore acid leaching solution after removing iron and aluminum, the specific steps are as follows: S1. Take the acid leaching solution of laterite nickel ore after removing iron and aluminum, whose components are the same as those in Example 1. Adjust the pH of the above-mentioned acid leaching solution of laterite nickel ore after removing iron and aluminum to 1 by adding concentrated sulfuric acid, and add an extractant for two-stage countercurrent extraction. The feed flow rate ratio of the extractant to the material to be extracted is 1:6 to obtain a first organic phase and a first aqueous phase; the extractant is composed of N1923, isooctanol and n-dodecane mixed in a volume ratio of 25%:10%:65%. The first organic phase contains scandium.

[0037] S2. Use a sulfuric acid solution as the first detergent, the concentration of the sulfuric acid solution is 1.5 M. Use the first detergent to perform two-stage first countercurrent washing on the first organic phase. The feed flow rate ratio of the first organic phase to the first detergent is 4:1 to obtain a second organic phase and a second aqueous phase; the second organic phase contains scandium; after testing and calculation, the washing rates (stripping rates) of scandium, cobalt, nickel, aluminum, iron, and zirconium are 1.26%, 98.33%, 99.52%, 97.85%, 71.11%, and 98.38% respectively. The washing rate of the difficult-to-wash accompanying element Ti is only 10.2%.

[0038] S3. For the accompanying elements that are difficult to wash, such as uranium and thorium, use a second detergent to perform two-stage second countercurrent washing on the second organic phase: use a mixed solution of 1 M sodium carbonate + 0.5 M ammonia water for washing again. Each time, the feed flow rate ratio of the second organic phase to the second detergent is 2:1 to obtain a third organic phase and a third aqueous phase; the third organic phase contains scandium; after testing and calculation, the washing rates of uranium and thorium are 93% and 88% respectively. During this washing process, by forming UO2(CO3)3 4- , Th(CO3)3 2- complexes, the effective separation of scandium from uranium and thorium can be further realized. In addition, the washing rates of other conventional impurity elements are also relatively high, so the effective separation of scandium from these impurities can be achieved.

[0039] S4. Use hydrochloric acid with a concentration of 3 M as the stripping agent to perform three-stage countercurrent stripping on the third organic phase. The feed flow rate ratio of the third organic phase to the stripping agent is 6:1 to obtain a fourth organic phase and a fourth aqueous phase; the fourth aqueous phase contains scandium; after testing and calculation, the stripping rate of scandium is 99.08%, while the stripping rates of the remaining impurity elements are all less than 1%. Therefore, this method can achieve the selective extraction of scandium and effectively separate impurities that meet national standards.

[0040] S5. Use oxalic acid as the precipitant, and the molar ratio of the precipitant to scandium in the fourth aqueous phase is 2:1. React the precipitant and the fourth aqueous phase at 70 °C for 2 h to form scandium oxalate precipitate, and perform calcination treatment on this precipitate at 700 °C for 3 h to obtain scandium oxide. After detection, the purity of the scandium oxide is 98.6%.

[0041] Comparative Example 2 A method for selectively extracting scandium from the acid leaching solution of laterite nickel ore after removing iron and aluminum, the specific steps are as follows: S1. Take the acid leaching solution of laterite nickel ore after removing iron and aluminum, whose components are the same as those in Example 1. Adjust the pH of the above acid leaching solution of laterite nickel ore after removing iron and aluminum to 1 by adding concentrated sulfuric acid, add an extractant for 2-stage countercurrent extraction, and the feed flow ratio of the extractant to the material to be extracted is 1:6 to obtain a first organic phase and a first aqueous phase; the extractant is composed of N1923, isooctanol and n-dodecane mixed in a volume ratio of 25%:10%:65%. The first organic phase contains scandium.

[0042] S2. Use a mixed solution of sulfuric acid solution and hydrogen peroxide as the first detergent, the concentration of the sulfuric acid solution is 1.5 M, the concentration of the hydrogen peroxide is 2.5%, and the volume ratio of the sulfuric acid solution to the hydrogen peroxide is 10:1; use the first detergent to carry out 2-stage first countercurrent washing on the first organic phase, and the feed flow ratio of the first organic phase to the first detergent is 4:1 to obtain a second organic phase and a second aqueous phase; the second organic phase contains scandium; after testing and calculation, the washing rates (stripping rates) of scandium, cobalt, nickel, aluminum, iron, and zirconium are 1.26%, 98.33%, 99.52%, 97.85%, 71.11%, and 98.38% respectively. The difficult-to-wash accompanying element Ti forms [TiO(H2O2)] through complex washing with hydrogen peroxide 2+ , and the removal rate reaches 99%.

[0043] S3. For accompanying elements such as uranium and thorium that are difficult to wash, use a 0.2 M sodium carbonate solution as the second detergent to carry out 2-stage second countercurrent washing on the second organic phase. Each time, the feed flow ratio of the second organic phase to the second detergent is 2:1 to obtain a third organic phase and a third aqueous phase; the third organic phase contains scandium; after testing and calculation, the washing rates of uranium and thorium are only 0.23% and 1.12% respectively.

[0044] S4. Use 3 M hydrochloric acid as the stripping agent to carry out 3-stage countercurrent stripping on the third organic phase, and the feed flow ratio of the third organic phase to the stripping agent is 6:1 to obtain a fourth organic phase and a fourth aqueous phase; the fourth aqueous phase contains scandium; after testing and calculation, the stripping rate of scandium is 99.08%, while the stripping rates of the remaining impurity elements are all less than 1%. Therefore, this method can realize the selective extraction of scandium and effectively separate impurities that meet national standards.

[0045] S5. Use oxalic acid as the precipitant, and the molar ratio of the precipitant to scandium in the fourth aqueous phase is 2:1. React the precipitant and the fourth aqueous phase at 70 °C for 2 h to generate scandium oxalate precipitate, and calcine the precipitate at 700 °C for 3 h to obtain scandium oxide. After detection, the purity of the scandium oxide is 99.5%.

[0046] Comparing Example 1 with Comparative Example 1, it can be seen that in the first countercurrent washing process, when the first detergent is changed from the hydrogen peroxide-sulfuric acid mixed solution in Example 1 to a pure sulfuric acid solution, the washing rate of the associated element Ti decreases significantly. This is because hydrogen peroxide can react with the titanium ((RNH3)2TiO) loaded in the organic phase to form [TiO(H2O2)] 2+ complex, which promotes the stripping of titanium from the organic phase and retains it in the aqueous phase, while scandium remains stable in the organic phase, thus achieving the effective separation of the two.

[0047] Comparing Example 1 with Comparative Example 2, it can be seen that in the secondary countercurrent washing stage, when a 0.2M sodium carbonate solution is used to replace the sodium carbonate-ammonia mixed detergent in Example 1, the washing rates of uranium and thorium decrease significantly respectively. This is because the lack of carbonate ligands makes it impossible to form UO2(CO3)3 4- and Th(CO3)3 2- soluble complexes, resulting in the retention of uranium and thorium ions in the scandium-containing organic phase and making it difficult to separate them.

[0048] Comparative Example 3 Take the acid leaching solution of laterite nickel ore after removing iron and aluminum, whose components are the same as those in Example 1. Adjust the pH of the above-mentioned acid leaching solution of laterite nickel ore after removing iron and aluminum to 1 by adding concentrated sulfuric acid, add an extractant for 2-stage countercurrent extraction, and the feed flow ratio of the extractant to the material to be extracted is 1:6 to obtain a first organic phase and a first aqueous phase; the extractant is composed of P204, isooctanol and n-dodecane mixed in a volume ratio of 25%:10%:65%. Comparative Example 4 Take the acid leaching solution of laterite nickel ore after removing iron and aluminum, whose components are the same as those in Example 1. Adjust the pH of the above-mentioned acid leaching solution of laterite nickel ore after removing iron and aluminum to 1 by adding concentrated sulfuric acid, add an extractant for 2-stage countercurrent extraction, and the feed flow ratio of the extractant to the material to be extracted is 1:6 to obtain a first organic phase and a first aqueous phase; the extractant is composed of N235, isooctanol and n-dodecane mixed in a volume ratio of 25%:10%:65%. The extraction effects of Example 1 and Comparative Examples 3-4 using different scandium extractants were statistically analyzed, and the results are shown in Table 2.

[0049] The statistical results of the extraction effects of Example 1 and Comparative Examples 3-4 using different scandium extractants are shown in Table 2.

[0050] Table 2 Extraction effects of different scandium extractants

[0051] Referring to Table 2, it can be seen that when P204 of Example 3 and N235 of Example 4 are selected as scandium extractants, the extraction rates of Co and Ni are relatively high, resulting in co-extraction of these elements with scandium and making it difficult to achieve effective separation. Therefore, N1923 is selected as the scandium extractant in the present invention.

[0052] The specific embodiments of the present invention described above do not constitute a limitation on the protection scope of the present invention. Any other corresponding changes and deformations made according to the technical concept of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. A method for selectively extracting scandium from the acid leaching solution of laterite nickel ore after removing iron and aluminum, characterized in that, It includes the following steps: S1. Adjust the pH of the laterite nickel ore acid leaching solution after removing iron and aluminum to 0.5 - 2, add an extractant for extraction to obtain a first organic phase and a first aqueous phase; S2. Perform a first countercurrent washing on the first organic phase with a first detergent to obtain a second organic phase and a second aqueous phase; S3. Perform a second countercurrent washing on the second organic phase with a second detergent to obtain a third organic phase and a third aqueous phase; S4. Perform a countercurrent stripping on the third organic phase with a stripping agent to obtain a fourth organic phase and a fourth aqueous phase; S5. React a precipitating agent with the fourth aqueous phase to generate a precipitate, and perform a calcination treatment on the precipitate to obtain scandium oxide.

2. The method for selectively extracting scandium from the acid leaching solution of laterite nickel ore after removing iron and aluminum according to claim 1, characterized in that, After step S4, it further includes recycling the fourth organic phase as an extractant to step S1.

3. The method for selectively extracting scandium from the acid leaching solution of laterite nickel ore after removing iron and aluminum according to claim 1, wherein, In step S1, the pH is adjusted by adding concentrated sulfuric acid; and / or In step S1, the extractant is composed of a scandium extractant, an organic alcohol, and a diluent mixed in a volume ratio of 20% - 30%: 5% - 15%: 55% - 75%.

4. The method for selectively extracting scandium from the acid leaching solution of laterite nickel ore after removing iron and aluminum according to claim 3, characterized in that, The scandium extractant is a secondary carbon primary amine extractant N - 1923; and / or The organic alcohol is at least one of isooctanol and sec - octanol; and / or The diluent is at least one of solvent oil No. 260 and dodecane.

5. The method for selectively extracting scandium from the acid leaching solution of laterite nickel ore after removing iron and aluminum according to claim 1, characterized in that, The specific manner of extraction in step S1 is countercurrent extraction, the extraction stage of countercurrent extraction is 1 - 3, and the feed flow ratio of the extractant to the material to be extracted is 1:4 - 8; and / or The first countercurrent washing in step S2 is 1 - 3 - stage washing, and the feed flow ratio of the first organic phase to the first detergent is 0.5 - 5:

1.

6. The method for selectively extracting scandium from the acid leaching solution of laterite nickel ore after removing iron and aluminum according to claim 1, characterized in that, The first detergent in step S2 includes a mixed solution of a sulfuric acid solution and hydrogen peroxide, the concentration of the sulfuric acid solution is 0.5 - 3 M, the concentration of the hydrogen peroxide is 1% - 5%, and the volume ratio of the sulfuric acid solution to the hydrogen peroxide is 10:0.25 - 1.

25.

7. The method for selectively extracting scandium from the acid leaching solution of laterite nickel ore after removing iron and aluminum according to claim 1, characterized in that, The second countercurrent washing in step S3 is 1 - 3 - stage washing, and the feed flow ratio of the second organic phase to the second detergent is 0.5 - 5:1; The second detergent described in step S3 is a carbonate / bicarbonate-alkaline solution mixed system, where the concentration of carbonate / bicarbonate is 0.3 - 1.2 M; for the alkaline solution system, liquid caustic soda or ammonia water is used, and its OH - concentration is 0.25 - 1.5 M.

8. The method for selectively extracting scandium from the acid leaching solution of laterite nickel ore after removing iron and aluminum according to claim 1, characterized in that, The countercurrent stripping in step S4 is 1 - 3 - stage stripping, and the feed flow ratio of the third organic phase to the stripping agent is 2 - 8:

1.

9. The method for selectively extracting scandium from the acid leaching solution of laterite nickel ore after removing iron and aluminum according to claim 1, wherein The stripping agent in step S4 is at least one of hydrochloric acid and nitric acid; The molar ratio of the precipitating agent to scandium in the fourth aqueous phase in step S5 is 1.5 - 3:

1.

10. The method for selectively extracting scandium from the acid leaching solution of laterite nickel ore after removing iron and aluminum according to claim 9, characterized in that, The precipitating agent and the fourth aqueous phase react at 60 - 80 °C for 2 - 5 h to generate a precipitate; The temperature of the calcination treatment in step S5 is 650 - 850 °C, and the time is 2 - 4 h.

Images