A process for the extraction of gallium and aluminium from sulphuric acid leach solutions
Patent Information
- Application Number
- CN202610785703.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-06-02
- Publication Date
- 2026-09-04
AI Technical Summary
[0004]尽管上述萃取剂均可实现镓的分离富集，但相关工艺仍存在诸多不足：（1）P204、P507和Cyanex272需在低酸环境（硫酸浓度小于10 g/L）下萃取镓，且萃取过程中会同步萃取铝，对二者的选择性较差，反萃过程中镓和铝同步被反萃出来；（2）OPAP可从高浓度硫酸中萃取镓，萃取率极高，即使硫酸浓度达80 g/L，镓的萃取率仍能达到90%，但同步萃取的铝至今无法找到合适的反萃剂从负载有机相中反萃出来，导致该工艺难以实际应用
上述方案，采用新型的磷酸酯类萃取剂，在复配的萃取体系下实现一步镓萃取，分步反萃分离富集镓和铝，工艺方法简单，生产成本低，镓和铝分离效果好，具有广泛的工业应用价值。具体的，
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Abstract
Description
Technical Field
[0001] This invention relates to the field of rare gallium metal recovery technology, and in particular to an extraction method for separating gallium and aluminum from sulfuric acid leaching solution. Background Technology
[0002] Currently, gallium is an important rare metal, with 90% of metallic gallium originating from aluminum smelting, and the remainder from zinc smelting and coal. Due to their similar properties, aluminum is one of the most critical byproduct metals in the gallium separation process.
[0003] To achieve a high gallium leaching rate, high-concentration sulfuric acid is required for leaching gallium-enriched slag generated during the smelting process. However, aluminum usually enters the leaching solution along with gallium. Therefore, aluminum separation is a key technology in separating gallium-enriched gallium from gallium- and aluminum-containing sulfuric acid leaching solutions. Currently, phosphate ester extractants, including P204, P507, Cyanex 272, and OPAP, are mainly used for extracting and separating gallium from gallium-containing sulfuric acid leaching solutions.
[0004] Although the above extractants can all achieve the separation and enrichment of gallium, the related processes still have many shortcomings: (1) P204, P507 and Cyanex272 need to be extracted in a low acid environment (sulfuric acid concentration less than 10 g / L), and aluminum will be extracted simultaneously during the extraction process. The selectivity for both is poor, and gallium and aluminum are extracted simultaneously during the back-extraction process; (2) OPAP can extract gallium from high-concentration sulfuric acid with extremely high extraction rate. Even if the sulfuric acid concentration reaches 80 g / L, the gallium extraction rate can still reach 90%. However, the aluminum extracted simultaneously cannot be extracted from the supported organic phase by a suitable back-extraction agent, which makes the process difficult to apply in practice.
[0005] In summary, existing processes for selectively extracting and recovering gallium from gallium- and aluminum-containing sulfuric acid leaching solutions cannot effectively separate gallium and aluminum in the solution. These processes suffer from problems such as a narrow selectivity range of the extractant, difficulty in production control, and high aluminum impurity content in the resulting gallium-containing products. These issues significantly increase the difficulty of gallium extraction and recovery, and severely limit the recovery of gallium resources. Summary of the Invention
[0006] To address the aforementioned technical problems in the existing technology, this invention provides an extraction method for separating gallium and aluminum from sulfuric acid leaching solution. The technical solution is as follows:
[0007] An extraction method for separating gallium and aluminum from a sulfuric acid leaching solution, the method comprising: S1. The sulfuric acid leaching solution containing gallium and aluminum is subjected to liquid-liquid extraction I with a compounded organic phase; S2. The loaded organic phase I obtained from liquid-liquid extraction I in S1 is washed with acid solution to obtain the loaded organic phase II and the washing liquid. The washing liquid is returned to S1 and mixed with sulfuric acid leaching solution as the extraction feed solution. S3. The supported organic phase II obtained in S2 is back-extracted with acid solution to obtain the supported organic phase III and gallium back-extraction solution I. S4. The supported organic phase III obtained by back-extraction I in S3 is back-extracted II with acid solution to obtain aluminum back-extraction solution II; S5. The gallium back-extraction solution I obtained in S3 is passed into a homogeneous dialysis apparatus to obtain a low-acid gallium-containing solution. The free sulfuric acid obtained from dialysis is mixed with concentrated sulfuric acid and recycled into S3. The low-acid gallium-containing solution is neutralized with sodium hydroxide to obtain gallium enrichment. S6. Pass the aluminum back-extraction solution II obtained in S4 into a homogeneous dialysis apparatus to obtain a low-acid aluminum-containing solution. The free sulfuric acid obtained from dialysis is mixed with concentrated sulfuric acid and recycled into S4. The low-acid aluminum-containing solution is neutralized with sodium hydroxide to obtain an aluminum concentrate.
[0008] The organic phase in S1 comprises the following components: 10 vol% to 30 vol% alkyl phosphate extractant, 5 vol% to 20 vol% alcohol modifier, and the balance being kerosene diluent; The alcohol modifier is or Any one of them.
[0009] The alkyl phosphate extractant is composed of 80-90 mol% of monophosphate of formula (11) and 10-20 mol% of diphosphate of formula (12); R1 in formula (11) and formula (12) is one of C8~C15 alkyl groups; Equation (11) Equation (12).
[0010] The gallium- and aluminum-containing sulfuric acid leaching solution in S1 contains 0.1~3 g / L of gallium and 0.1~3 g / L of aluminum. The main impurities include Cu, Zn, and As. The concentration of Cu ions is less than 10 g / L, the concentration of Zn ions is less than 50 g / L, the concentration of As ions is less than 5 g / L, and the concentration of sulfuric acid ranges from 10 to 80 g / L.
[0011] The extraction temperature of liquid-liquid extraction I in S1 is 20-45℃, with a ratio of O / A of 1:1-5:1; the extraction time is 2-15 min.
[0012] The acid solution in S2 is one of sulfuric acid solution, nitric acid solution, hydrochloric acid solution, phosphoric acid solution and oxalic acid solution, with a concentration of 0.1~0.5mol / L, a washing temperature of 20~60℃, a ratio of O:A=1:1~1:8, and a washing time of 2.5~10min.
[0013] The acid solution in S3 is one of sulfuric acid solution, nitric acid solution, hydrochloric acid solution, phosphoric acid solution and oxalic acid solution, with a concentration of 2.0~2.5 mol / L. The back-extraction temperature of back-extraction I is 20~30℃, with a ratio of O / A of 1:1~1:10 and a back-extraction time of 2.5~25 min.
[0014] The acid solution in S4 is one of sulfuric acid solution, nitric acid solution, hydrochloric acid solution, phosphoric acid solution and oxalic acid solution, with a concentration of 3.0~5.0 mol / L. The back-extraction temperature of back-extraction II is 65~95 ℃, with a ratio of O / A = 1:1~1:10. The back-extraction time is 5~25 min.
[0015] The temperature at which sodium hydroxide is added for neutralization in S5 and S6 is 65–95 °C, the pH after neutralization is 3.5–5.5, and the reaction time is 0.5–2 h.
[0016] The above method, through one-step extraction (i.e., liquid-liquid extraction I) and stepwise back-extraction (i.e., back-extraction I and back-extraction II), achieves the extraction, separation, and enrichment of gallium and aluminum from gallium- and aluminum-containing sulfuric acid leachates, respectively. During the extraction process, the single-stage extraction rate of gallium is greater than 90%, while the single-stage co-extraction rate of aluminum is less than 15%. In the stepwise back-extraction: during gallium back-extraction, the single-stage back-extraction rate of gallium is greater than 90%, while the single-stage back-extraction rate of aluminum is less than 6%; during aluminum back-extraction, the single-stage back-extraction rate of aluminum is greater than 90%. The gallium back-extraction solution I obtained after back-extraction I is passed through a homogeneous dialysis membrane, and the low-acid gallium-containing solution III is neutralized to precipitate gallium, yielding a concentrate with a gallium content greater than 30%, which is used as a raw material for electrowinning the preparation of metallic gallium. The aluminum back-extraction solution I obtained after back-extraction II is passed through a homogeneous dialysis membrane, and the low-acid aluminum-containing solution IV is neutralized to precipitate aluminum, yielding a concentrate with an aluminum content greater than 28%, which is used as a raw material for preparing alumina. The free acid solution from dialysis is used to replenish the concentrated solution for recycling.
[0017] The liquid-liquid extraction I uses an organic phase with alkyl phosphate extractant, which has a long carbon chain and low water solubility, meeting the requirements for cyclic reuse. The alkyl phosphates with the structures of formula (11) and (12) have an acidity between P204 and OPAP extractants due to the electron-donating effect of the alkyl group. They can undergo hydrogen ionization in acidic systems and can exchange ions with gallium to achieve the purpose of extraction with a certain acid concentration without the need for acid adjustment.
[0018] By controlling the back-extraction temperature during the process, gallium and aluminum impurities can be effectively separated without introducing other chemical elements. After back-extraction, the high-acid solution is recycled through a dialysis unit, reducing production costs and improving product quality.
[0019] The beneficial effects of the technical solutions provided in the embodiments of the present invention include at least the following: The above scheme employs a novel phosphate ester extractant to achieve one-step gallium extraction in a compound extraction system, followed by stepwise back-extraction to separate and enrich gallium and aluminum. The process is simple, has low production costs, and provides excellent separation of gallium and aluminum, making it highly valuable for broad industrial applications. Specifically,
[0020] A novel phosphate ester extractant is used, whose extraction performance is between that of P204 and OPAP. In a compound extraction system, one-step gallium extraction is achieved. During this process, the gallium single-stage extraction rate is greater than 90%, and the aluminum single-stage co-extraction rate is less than 15%. Stepwise back-extraction is also performed: during gallium back-extraction, the gallium single-stage back-extraction rate is greater than 90%, while the aluminum single-stage back-extraction rate is less than 6%; during aluminum back-extraction, the aluminum single-stage back-extraction rate is greater than 90%. Attached Figure Description
[0021] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0022] Figure 1 This is a flowchart of an extraction method for separating gallium and aluminum from sulfuric acid leaching solution provided in an embodiment of the present invention. Detailed Implementation
[0023] The technical solution of the present invention will now be described with reference to the accompanying drawings.
[0024] In embodiments of the present invention, words such as "exemplarily," "for example," etc., are used to indicate that something is an example, illustration, or description. Any embodiment or design described as "exemplary" in the present invention should not be construed as being more preferred or advantageous than other embodiments or designs. Specifically, the use of the word "exemplary" is intended to present the concept in a concrete manner. Furthermore, in embodiments of the present invention, the meaning expressed by "and / or" can be both, or either one.
[0025] In this embodiment of the invention, sometimes a subscript such as W1 may be written in a non-subscript form such as W1. When the difference is not emphasized, the meaning they express is the same.
[0026] To make the technical problems, technical solutions and advantages of the present invention clearer, a detailed description will be given below in conjunction with the accompanying drawings and specific embodiments.
[0027] This invention provides an extraction method for separating gallium and aluminum from sulfuric acid leaching solution. For example... Figure 1 The flowchart shown illustrates an extraction method for separating gallium and aluminum from a sulfuric acid leaching solution. This method may include the following steps:
[0028] S1. The sulfuric acid leaching solution containing gallium and aluminum is subjected to liquid-liquid extraction I with a compounded organic phase; S2. The loaded organic phase I obtained from liquid-liquid extraction I in S1 is washed with acid solution to obtain the loaded organic phase II and the washing liquid. The washing liquid is returned to S1 and mixed with sulfuric acid leaching solution as the extraction feed solution. S3. The supported organic phase II obtained in S2 is back-extracted with acid solution to obtain the supported organic phase III and gallium back-extraction solution I. S4. The supported organic phase III obtained by back-extraction I in S3 is back-extracted II with acid solution to obtain aluminum back-extraction solution II; S5. The gallium back-extraction solution I obtained in S3 is passed into a homogeneous dialysis apparatus to obtain a low-acid gallium-containing solution. The free sulfuric acid obtained from dialysis is mixed with concentrated sulfuric acid and recycled into S3. The low-acid gallium-containing solution is neutralized with sodium hydroxide to obtain gallium enrichment. S6. Pass the aluminum back-extraction solution II obtained in S4 into a homogeneous dialysis apparatus to obtain a low-acid aluminum-containing solution. The free sulfuric acid obtained from dialysis is mixed with concentrated sulfuric acid and recycled into S4. The low-acid aluminum-containing solution is neutralized with sodium hydroxide to obtain an aluminum concentrate.
[0029] The following description, in conjunction with specific embodiments, illustrates this point.
[0030] Example 1 In this embodiment, the sulfuric acid concentration in the gallium and aluminum-containing sulfuric acid leaching solution is 20 g / L. The concentrations of Ga, Al, As, Zn, and Cu are shown in Table 1.
[0031] In this embodiment, the organic phase composition is: 15 vol% alkyl phosphate extractant + 10 vol% alcohol modifier + 85 vol% 260# sulfonated kerosene.
[0032] in: The alkyl phosphate extractant of this embodiment includes 83 mol% monophosphate and 17 mol% diphosphate.
[0033] Monophosphates have the following structure: Bisphosphonates have the following structure: Alcohol modifiers have the following structures: S1, Liquid-Liquid Extraction I: In this embodiment, a separatory funnel was used for single-stage extraction at an extraction temperature of 25°C, an extraction ratio of O / A of 1:1, and an extraction time of 10 min. This yielded a loaded organic phase I.
[0034] Table 1. Separation results of liquid-liquid extraction process I in Example 1 The results in Table 1 show that the single-stage extraction rates of gallium and aluminum during the liquid-liquid extraction process were 94.32% and 10.91%, respectively, while other impurities were extracted in trace amounts.
[0035] S2, Washing: The organic phase I was washed with a 0.4 mol / L sulfuric acid solution at a temperature of 35°C with a ratio of O / A of 1:1 for 10 min, resulting in the washed organic phase II and the washing solution (in Table 2, the organic phase washing solution is referred to as the washing solution).
[0036] S3, Back Extraction I: After washing the supported organic phase II by liquid-liquid extraction I, back-extracting it with 2.0 mol sulfuric acid solution using a separatory funnel yielded the supported organic phase III and gallium back-extraction solution I (in Table 2, this refers to the gallium back-extraction solution). The gallium back-extraction rate was calculated from a single back-extraction of gallium back-extraction solution I, and the results are shown in Table 2 below. The back-extraction temperature in back-extraction I was 25℃, with a ratio of O / A = 1:1; the back-extraction time was 10 min.
[0037] S4, Reverse Extraction II: Organic phase III was loaded and back-extracted in a single stage with 4 mol sulfuric acid solution using a separatory funnel to obtain aluminum back-extraction solution II (referring to aluminum back-extraction solution in Table 2). The aluminum back-extraction rate was calculated from aluminum back-extraction solution II, and the results are shown in Table 2 below. The back-extraction temperature in back-extraction II was 85℃, with a ratio of O / A = 1:1; the back-extraction time was 10 min.
[0038] Table 2. Separation results of back-extraction I and back-extraction II in Example 1 As can be seen from the results in Table 2, after gallium and aluminum are back-extracted separately, the single-stage back-extraction rate of gallium can reach 94.94%, while the aluminum back-extraction rate is only 5.71%. During the aluminum back-extraction process, the single-stage back-extraction rate of aluminum is 90.91%, where impurities are washed out during the washing process, and the remaining gallium in the gallium back-extraction process is completely back-extracted when aluminum is back-extracted.
[0039] S5, Enrichment: The gallium and aluminum back-extraction solutions in S4 were recycled and enriched to obtain high-concentration gallium back-extraction solution I (see Table 3, where gallium back-extraction solution is referred to in Table 3) and aluminum back-extraction solution II (see Table 4, where aluminum back-extraction solution is referred to in Table 4). The high-concentration back-extraction solutions were fed into a homogeneous dialysis unit to separate free sulfuric acid, resulting in dialysis free acid and low-acid gallium back-extraction solution (see Table 3, where gallium back-extraction solution is referred to in Table 3) and low-acid aluminum back-extraction solution (see Table 4, where aluminum back-extraction solution is referred to in Table 4). Sodium hydroxide was added for neutralization, and the reaction was carried out at a temperature of 75 °C, a pH of 5.0, and a reaction time of 1 h, yielding 41.64 g of gallium concentrate with a water content of 45% and 87.49 g of aluminum concentrate with a water content of 48.62%.
[0040] Table 3 Results of gallium back-extraction solution dialysis separation and neutralization precipitation in Example 1 Table 4 Results of dialysis separation and neutralization precipitation of aluminum back-extraction solution in Example 1 As shown in Tables 3 and 4, the enriched quantities of gallium and aluminum after precipitation are 30.56% and 28.47%, respectively.
[0041] Example 2 In this embodiment, the sulfuric acid leaching solution containing gallium and aluminum has a sulfuric acid concentration of 25 g / L. The concentrations of Ga, Al, As, Zn, and Cu are shown in Table 5.
[0042] In this embodiment, the organic phase composition is: 18 vol% alkyl phosphate extractant + 15 vol% alcohol modifier + 77 vol% 260# sulfonated kerosene.
[0043] in: The alkyl phosphate extractant of this embodiment includes 83 mol% monophosphate and 17 mol% diphosphate.
[0044] Monophosphates have the following structure: Bisphosphonates have the following structure: Alcohol modifiers have the following structures: S1, Liquid-Liquid Extraction I: In this embodiment, a separatory funnel was used for single-stage extraction at an extraction temperature of 30°C, an extraction ratio of O / A = 1:1, and an extraction time of 7.5 min. This yielded a loaded organic phase I.
[0045] Table 5. Separation results of liquid-liquid extraction process I in Example 2 The results in Table 5 show that the single-stage extraction rates of gallium and aluminum during the liquid-liquid extraction process were 94.44% and 10.19%, respectively, while other impurities were extracted in trace amounts.
[0046] S2, Washing: The organic phase I was washed with a 0.5 mol / L sulfuric acid solution at a temperature of 30°C with a ratio of O / A of 1:1 for 10 min, resulting in the washed organic phase II and the washing solution (in Table 6, the washing solution refers to the organic phase).
[0047] S3, Back Extraction I: After washing the supported organic phase II by liquid-liquid extraction I, back-extracting it with 2.5 mol sulfuric acid solution using a separatory funnel yielded the supported organic phase III and gallium back-extraction solution I (in Table 6, this refers to the gallium back-extraction solution). The gallium back-extraction rate was calculated from a single back-extraction of gallium back-extraction solution I, and the results are shown in Table 6 below. The back-extraction temperature in back-extraction I was 25℃, with a ratio of O / A = 1:1; the back-extraction time was 10 min.
[0048] S4, Reverse Extraction II: Organic phase III was loaded and back-extracted in a single stage with 5 mol sulfuric acid solution using a separatory funnel to obtain aluminum back-extraction solution II (referring to aluminum back-extraction solution in Table 6). The aluminum back-extraction rate was calculated from aluminum back-extraction solution II, and the results are shown in Table 6 below. The back-extraction temperature in back-extraction II was 90℃, with a ratio of O / A = 1:1; the back-extraction time was 10 min.
[0049] Table 6. Separation results of back-extraction I and back-extraction II in Example 2 As can be seen from the results in Table 6, after gallium and aluminum are back-extracted separately, the single-stage back-extraction rate of gallium can reach 96.91%, while the aluminum back-extraction rate is only 4.35%. During the aluminum back-extraction process, the single-stage back-extraction rate of aluminum is 95.45%, where impurities are washed out during the washing process, and the remaining gallium in the gallium back-extraction process is all back-extracted when aluminum is back-extracted.
[0050] S5, Enrichment: The gallium and aluminum back-extraction solutions in S4 were recycled and enriched to obtain high-concentration gallium back-extraction solution I (see Table 7, where gallium back-extraction solution is referred to in Table 7) and aluminum back-extraction solution II (see Table 8, where aluminum back-extraction solution is referred to in Table 8). The high-concentration back-extraction solution was fed into a homogeneous dialysis unit to separate free sulfuric acid, resulting in dialysis free acid and low-acid gallium back-extraction solution (see Table 7, where gallium back-extraction solution is referred to in Table 7) and low-acid aluminum back-extraction solution (see Table 8, where aluminum back-extraction solution is referred to in Table 8). Sodium hydroxide was added for neutralization, the temperature was 70 °C, the pH was 4.8, and the reaction time was 1 h. After filtration, 54.81 g of gallium concentrate with 48% water content and 154.02 g of aluminum concentrate with 50.5% water content were obtained.
[0051] Table 7 Results of gallium back-extraction solution dialysis separation and neutralization precipitation in Example 2 Table 8 Results of dialysis separation and neutralization precipitation of aluminum back-extraction solution in Example 2 As shown in Tables 7 and 8, the precipitated gallium and aluminum enrichments have grades of 32.10% and 28.20%, respectively.
[0052] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.
Claims
1. An extraction method for separating gallium and aluminum from sulfuric acid leaching solution, characterized in that, The method includes: S1. The sulfuric acid leaching solution containing gallium and aluminum is subjected to liquid-liquid extraction I using a compounded organic phase; S2. The loaded organic phase I obtained from liquid-liquid extraction I in S1 is washed with acid solution to obtain the loaded organic phase II and the washing liquid. The washing liquid is returned to S1 and mixed with sulfuric acid leaching solution as the extraction feed solution. S3. The supported organic phase II obtained in S2 is back-extracted with acid solution to obtain the supported organic phase III and gallium back-extraction solution I. S4. The supported organic phase III obtained by back-extraction I in S3 is back-extracted II with acid solution to obtain aluminum back-extraction solution II; S5. The gallium back-extraction solution I obtained in S3 is passed into a homogeneous dialysis apparatus to obtain a low-acid gallium-containing solution. The free sulfuric acid obtained from dialysis is mixed with concentrated sulfuric acid and recycled into S3. The low-acid gallium-containing solution is neutralized with sodium hydroxide to obtain gallium enrichment. S6. Pass the aluminum back-extraction solution II obtained in S4 into a homogeneous dialysis apparatus to obtain a low-acid aluminum-containing solution. The free sulfuric acid obtained from dialysis is mixed with concentrated sulfuric acid and recycled into S4. The low-acid aluminum-containing solution is neutralized with sodium hydroxide to obtain an aluminum concentrate.
2. The extraction method for separating gallium and aluminum from sulfuric acid leaching solution according to claim 1, characterized in that, The organic phase in S1 comprises the following components: 10 vol% to 30 vol% alkyl phosphate extractant, 5 vol% to 20 vol% alcohol modifier, and the balance being kerosene diluent; The alcohol modifier is or Any one of them.
3. The extraction method for separating gallium and aluminum from sulfuric acid leaching solution according to claim 2, characterized in that, The alkyl phosphate extractant is composed of 80-90 mol% of monophosphate of formula (11) and 10-20 mol% of diphosphate of formula (12); R1 in formula (11) and formula (12) is one of C8~C15 alkyl groups; Equation (11) Equation (12).
4. The extraction method for separating gallium and aluminum from sulfuric acid leaching solution according to claim 1, characterized in that, The gallium- and aluminum-containing sulfuric acid leaching solution in S1 contains 0.1~3 g / L of gallium and 0.1~3 g / L of aluminum, with a Cu ion concentration of less than 10 g / L, a Zn ion concentration of less than 50 g / L, an As ion concentration of less than 5 g / L, and a sulfuric acid concentration range of 10~80 g / L.
5. The extraction method for separating gallium and aluminum from sulfuric acid leaching solution according to claim 1, characterized in that, The extraction temperature of liquid-liquid extraction I in S1 is 20-45℃, with a ratio of O / A of 1:1-5:1; the extraction time is 2-15 min.
6. The extraction method for separating gallium and aluminum from sulfuric acid leaching solution according to claim 1, characterized in that, The acid solution in S2 is one of sulfuric acid solution, nitric acid solution, hydrochloric acid solution, phosphoric acid solution and oxalic acid solution, with a concentration of 0.1~0.5mol / L, a washing temperature of 20~60℃, a ratio of O:A=1:1~1:8, and a washing time of 2.5~10min.
7. The extraction method for separating gallium and aluminum from sulfuric acid leaching solution according to claim 1, characterized in that, The acid solution in S3 is one of sulfuric acid solution, nitric acid solution, hydrochloric acid solution, phosphoric acid solution and oxalic acid solution, with a concentration of 2.0~2.5 mol / L. The back-extraction temperature of back-extraction I is 20~30℃, with a ratio of O / A of 1:1~1:10 and a back-extraction time of 2.5~25 min.
8. The extraction method for separating gallium and aluminum from sulfuric acid leaching solution according to claim 1, characterized in that, The acid solution in S4 is one of sulfuric acid solution, nitric acid solution, hydrochloric acid solution, phosphoric acid solution and oxalic acid solution, with a concentration of 3.0~5.0 mol / L. The back-extraction temperature of back-extraction II is 65~95 ℃, with a ratio of O / A = 1:1~1:
10. The back-extraction time is 5~25 min.
9. The extraction method for separating gallium and aluminum from sulfuric acid leaching solution according to claim 1, characterized in that, The temperature at which sodium hydroxide is added for neutralization in S5 and S6 is 65–95 °C, the pH after neutralization is 3.5–5.5, and the reaction time is 0.5–2 h.