Synergistic extraction of aluminum, iron, lithium, and gallium from high-aluminum solid waste acidic systems.

Abstract

To provide a method for collaboratively extracting aluminum, iron, lithium, and gallium from a high aluminum solid waste acidic system.SOLUTION: In step 1, TBP is employed as an extractant first, Fe, Li, Ga are extracted from a complicated acidic system to acquire extracted residual liquid 1, and then, back-extraction is performed by using water or dilute acid to acquire solution 2 containing Fe, Li, Ga. In step 2, quaternary ammonium salt or quaternary phosphonium salt extractant is employed to extract the solution 2 to acquire an organic phase carrying Fe, Ga and Li-containing extracted residual liquid 3, the organic phase carrying Fe, Ga is back-extracted by dilute acid to acquire solution 4 containing Fe, Ga. In step 3, the solution 4 in step 2 is extracted by 2-ethylhexyl phosphoric acid mono-2-ethylhexyl to acquire an organic phase carrying Fe and Ga-containing extracted residual liquid 5, and the organic phase carrying Fe is back-extracted by sulfuric acid to acquire solution containing Fe.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention belongs to the technical field of integrated resource utilization, and specifically relates to a method for synergistically extracting aluminum, iron, lithium, and gallium from an acidic system of high-aluminum solid waste. [Background technology]

[0002] Lithium is an important strategic energy metal, and gallium is an important rare metal, also known as the "spice of the electronics industry." They are widely used in strategic emerging fields such as aerospace, nuclear power development, new energy vehicles, and electronic materials, and play an important role in national defense and national economic development. With China's industrial structure undergoing transformation and the rapid development of the new energy vehicles and electronic materials industries, demand for lithium and gallium products is rapidly increasing. However, China's supply of lithium and gallium resources lags far behind market demand, with the country's lithium dependence at over 70%. The country's proven gallium reserves are only 100,000 tons. Gallium does not form independently in nature; it is primarily extracted from bauxite and zinc slag, with gallium extracted from bauxite accounting for 90% of total production. Coalfields in northern Shanxi Province and Inner Mongolia, among others, contain abundant lithium, gallium, rare earth elements, and other important rare metals, in addition to major elements such as aluminum, silicon, and iron. Solid waste gangue from coal mining also contains large amounts of associated strategic metals. After coal is burned and fly ash is produced, lithium and gallium are further concentrated in the ash, exceeding industrial mining grades (Li: 200 μg / g, Ga: 30 μg / g). The reserves are huge, making them highly valuable for mining.

[0003] As solid waste or low-grade resources, their mineral phases are highly complex, with low and highly dispersed associated strategic metals such as lithium and gallium. Their individual extraction costs, energy consumption, and economic benefits are high. Utilizing the large-volume elements of aluminum and silicon while synergistically extracting the strategic metals lithium and gallium would not only improve the economic efficiency of the process, but also open up new routes for the supply of lithium and gallium resources and, to some extent, alleviate the shortage of strategic metal resources. Therefore, synergistic extraction of multiple elements is an inevitable trend. Generally, elements are transferred to the leachate by leaching, and then separated and refined. The leachate is a complex system with high ionic strength and multiple ions coexisting. The ion diversity is high, and some elements have very similar chemical properties, making separation difficult. Therefore, selective separation and enrichment are key to extracting associated elements and utilizing them as resources.

[0004] There have been several reports on the collaborative separation of Al, Li, and Ga from fly ash leachate. Sun Yuzhuang of Hebei Polytechnic University has published Chinese patent CN102923742A, which proposes a method for extracting aluminum and lithium from fly ash comprehensively. This method involves desiliconization, magnetic iron removal, limestone activation, alkaline leaching, and carbonization. After alkaline leaching, a solution containing aluminum and lithium is obtained. The solution is carbonized and then subjected to solid-liquid separation to obtain a mother liquor containing Li and Al(OH)3. The former is evaporated and concentrated to obtain lithium carbonate, and the Al(OH)3 is calcined to obtain Al2O3. Li Shaopeng of the Institute of Process Engineering, Chinese Academy of Sciences, in his published Chinese patent CN107758714A, proposed a method for the synergistic extraction of aluminum, silicon, lithium, and gallium from fly ash. The method involves pre-desiliconizing the fly ash with an alkaline solution, removing impurities from the desiliconizing solution, adsorbing it on a lithium ion sieve, and concentrating and precipitating it to obtain a lithium carbonate product. The desiliconized slag is then subjected to the Bayer process to extract aluminum to produce an aluminum hydroxide product. The Bayer process seed precipitation mother liquor is recycled multiple times, adsorbed, and rinsed to obtain a gallium-rich solution. Metallic gallium is then obtained through concentration, crystallization, and electrolysis. This process achieves the synergistic extraction of Al, Li, and Ga from the fly ash leachate. Currently reported multi-element synergistic extraction processes are based on alkaline fly ash systems, which require long processing times and are complex.

[0005] Because solid wastes such as fly ash and gangue have low Al / Si ratios, alkaline extraction requires large amounts of slag and alkaline consumption. However, using an acidic medium offers advantages such as a simple leaching process, minimal slag, and a high leaching rate of valuable metals. The separated silicon slag can also be further utilized as a resource. This makes it an effective process for recycling gangue and fly ash. The one-step acid pasting method can extract large amounts of aluminum, lithium, gallium, iron, and other elements. However, the large number of elements in the acidic leachate and the complex system present challenges for acidic separation. Regarding the separation of Li and Ga using acidic systems, current efforts focus on the isolation of Li or Ga alone. Shenhua Group, in Chinese Patent CN103101935A, disclosed a method for preparing lithium carbonate from fly ash. The aluminum chloride crystal mother liquor used in the fly ash acid extraction process was repeatedly recycled and evaporated to concentrate lithium. The lithium carbonate was then prepared through a series of processes, including purification, impurity removal, iron removal, aluminum-lithium coprecipitation, calcination, leaching, and the addition of sodium carbonate to precipitate lithium. Li Lijuan of the Qinghai Salt Lake Institute, Chinese Academy of Sciences, in Chinese Patent CN108265176A, disclosed a method for extracting lithium from fly ash. The author selectively extracted lithium from the fly ash acid leachate using a TBP-FeCl3-kerosene extraction system, followed by multi-level countercurrent extraction, washing, and stripping to obtain a LiCl solution. Chinese Patent CN109897961A disclosed a method for stepwise separation, impurity removal, and aluminum-gallium synergistic extraction from fly ash in a sulfuric acid system. In summary, currently, the extraction of Li and Ga from acidic systems is mostly the separation of single elements, and there have been no reports of the synergistic extraction of Al, Fe, Li, and Ga in acidic leaching solutions. Summary of the Invention [Problem to be solved by the invention]

[0006] The present invention addresses the problems of the large number of metal elements in the acidic leachate of high-aluminum solid waste, the difficulty of selective separation, and the high cost of extracting lithium and gallium separately, by providing a method for synergistically extracting aluminum, iron, lithium, and gallium from the acidic system of high-aluminum solid waste. [Means for solving the problem]

[0007] To achieve the above object, the present invention provides the following technical solutions:

[0008] 1. A method for synergistically extracting aluminum, lithium, and gallium from a high-aluminum solid waste acidic system, comprising: The acidic leachate of high-aluminum solid waste and the organic phase are mixed in a volume ratio of 1:3 to 3:1, and then extracted. After phase separation, the organic phase carrying Fe, Li, and Ga and the Al-containing raffinate are obtained. Step 1: Mixing the organic phase carrying Fe, Li, and Ga with hydrochloric acid in a volume ratio of 1:2 to 1:3 and back-extracting to obtain a mixed solution of Fe, Li, and Ga; The Fe, Li, and Ga mixed solution and the organic phase are mixed in a volume ratio of 1:3 to 3:1, and then extracted. After phase separation, the organic phase carrying Fe and Ga and the Li-containing raffinate are obtained. Step 2: Mixing the organic phase carrying Fe and Ga with sulfuric acid in a volume ratio of 1:2 to 1:3 and performing back extraction to obtain a mixed solution containing Fe and Ga; The mixed solution containing Fe and Ga and the organic phase are mixed at a volume ratio of 1:3 to 3:1, and then extracted to obtain an organic phase carrying Fe and a Ga-containing raffinate; and step 3 of mixing the organic phase carrying Fe with sulfuric acid at a volume ratio of 1:2 to 1:3 to perform back extraction to obtain an Fe solution.

[0009] Furthermore, in the step 1, the high-aluminum solid waste is a mixture of one or more of fly ash, gangue, and low-grade bauxite in any ratio, the acidic leaching solution is a hydrochloric acid solution with a pH of 0-1, the extraction time is 5-30 minutes, and the back-extraction time is 30-60 minutes.

[0010] Furthermore, in step 1, the organic phase contains an extractant and a diluent, the extractant is tributyl phosphate (TBP), the diluent is a mixture of one or more of 260# solvent oil, dichloromethane, chloroform, and 1,2-dichloroethane in any ratio, and the concentration of hydrochloric acid is 0-1 mol / L (deionized water is added when it is 0 mol / L).

[0011] Furthermore, in step 2, the organic phase contains an extractant, and the extractant is a quaternary phosphonium salt or a quaternary ammonium salt, for example, [P 14,6,6,6 ]Cl, [N 8,8,8,1 ]Cl, [P 14,6,6,6 ]Br, [N 4,4,4,4 ]Cl, etc., the extraction time is 5 to 30 minutes, the back-extraction time is 30 to 60 minutes, and the sulfuric acid concentration is 0.1 to 0.5 mol / L.

[0012] Furthermore, the organic phase further comprises a diluent, and the diluent is a mixture of one or more of 260# solvent oil, dichloromethane, chloroform, and 1,2-dichloroethane in any ratio.

[0013] Furthermore, in step 3, the organic phase contains an extractant and a diluent, the extractant is mono-2-ethylhexyl 2-ethylhexylphosphonate (P507), the diluent is a mixture of one or more of 260# solvent oil, dichloromethane, chloroform, and 1,2-dichloroethane in any ratio, and the sulfuric acid concentration is 1.0 to 4.0 mol / L.

[0014] Furthermore, in step 3, the extraction time is 30 to 60 minutes, and the back-extraction time is 30 to 60 minutes.

[0015] The Al-containing raffinate obtained in the above extraction process can be evaporated and crystallized to obtain high-quality crystalline aluminum chloride products. The Li-containing raffinate and Ga-containing raffinate can be further purified, concentrated, and enriched, and then processed by carbonization or electrodeposition to prepare products such as lithium carbonate and metallic gallium, and the Fe solution can be hydrothermally reacted to prepare α-Fe2O3. [Effects of the Invention]

[0016] Compared with the prior art, the present invention has the following advantages:

[0017] This invention employs TBP as an extractant to extract Li / Fe / Ga from a complex acidic system in one step, simplifying the separation system and reducing the acidity and Cl for subsequent separation. - This reduces the interference of elements, and then, through a two-step extraction-back extraction process, achieves the stepwise selective separation of Al, Li, Ga, and Fe in the acid leachate. The separated Al, Li, Ga, and Fe solutions can be used to prepare high-quality crystalline aluminum chloride, lithium carbonate, electrolytic gallium, and α-Fe2O3 products, achieving the synergistic extraction and high-value-added utilization of Al, Li, Ga, and Fe in the acid leachate. Compared with the fly ash-alkali method for synergistic element extraction, this technological process is simpler, has a shorter flow rate, and has higher separation efficiency. [Brief explanation of the drawings]

[0018] [Figure 1] 1 is a flow chart of the method for synergistically extracting aluminum, iron, lithium, and gallium from a high-aluminum solid waste acidic system of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0019] [Example 1] As shown in Figure 1, the method for synergistic extraction of aluminum, lithium, and gallium from high-aluminum solid waste acidic systems includes the following steps:

[0020] Step 1, Extraction-Back Extraction: After acid leaching of fly ash with hydrochloric acid, solid-liquid separation was performed to obtain an acidic leachate containing 56.7 g / L Al, 5.1 g / L Fe, 202 mg / L Li, and 105 mg / L Ga. 10 mL of the acidic leachate was mixed with 5 mL of 2 mol / L TBP, diluented with dichloromethane, and the pH of the acidic leachate was adjusted to approximately 0.4. The reaction time was 30 min. After the reaction was completed, the mixture was allowed to stand for phase separation, yielding an organic phase containing Li, Fe, and Ga, and an Al-containing raffinate. The aqueous phase was tested and calculated to yield 84.2% Fe extraction, 80.9% Li extraction, and 97.5% Ga extraction, with a small amount of Al entrained. Extraction was performed at room temperature.

[0021] 5 mL of TBP loaded with Fe, Li, and Ga was mixed with 10 mL of deionized water for 30 min. After the back-extraction, the mixture was allowed to stand for phase separation, and Fe, Li, and Ga were almost completely back-extracted.

[0022] Step 2, Extraction-Back Extraction: 5 mL of the Fe, Li, Ga mixed solution in step 1 and 5 mL of [N 8,8,8,1 ]Cl was mixed, and the extraction time was 30 min. After extraction, the mixture was allowed to stand and separated into layers, and an organic phase carrying Fe and Ga and an extract containing Li were obtained. The aqueous phase was tested by ICP-OES, and the extraction rate of Fe was 99.9%, the extraction rate of Ga was 97.2%, and almost no Li was extracted, with the Li concentration in the solution being 160 mg / L. In this example, the recovery rate of Li was approximately 80%.

[0023] 5 mL of the organic phase containing Fe and Ga was mixed with 10 mL of 0.1 mol / L H2SO4 solution and stripped at room temperature for 30 minutes. After stripping, the mixture was allowed to stand for phase separation and the stripped solution was tested. The stripping rate of Fe was 83.3% and that of Ga was 92.1%, yielding a mixed Fe and Ga solution.

[0024] Step 3, Extraction-Back Extraction: 5 mL of the Fe and Ga mixed solution from step 2 was mixed with 5 mL of 1 mol / L P507, and the diluent was 260°C sulfonated kerosene. The equilibrium pH was controlled to approximately 0.8. After 30 minutes of extraction, the mixture was allowed to stand to separate into phases, yielding Fe-loaded P507 and Ga-containing raffinate. The aqueous phase was tested, and the Fe removal rate reached 96.6%, with approximately 10% Ga entrained. The Ga concentration in the raffinate reached 67 mg / L. In this example, the Ga recovery rate was approximately 65%.

[0025] 5 mL of the Fe-loaded P507 was mixed with 10 mL of 4 mol / L H2SO4 solution and stripped at room temperature for 30 min. After stripping, the mixture was allowed to stand for phase separation, and the aqueous phase was tested. The stripping rate of Fe was 93.4%.

[0026] The organic phase that has undergone the back-extraction can be regenerated and reused in a new extraction process.

[0027] [Example 2] The method for synergistic extraction of aluminum, lithium, and gallium from a high-aluminum solid waste acidic system comprises the following steps:

[0028] Step 1, Extraction-Back Extraction: Low-grade bauxite was leached with hydrochloric acid and then solid-liquid separation yielded an acidic leachate containing 83.5 g / L Al, 5.8 g / L Fe, 210 mg / L Li, and 32 mg / L Ga. The pH of the acidic leachate was adjusted to 1 with hydrochloric acid, and 10 mL of the acidic leachate was mixed with 5 mL of 2 mol / L TBP. The diluent was dichloromethane, and the reaction time was 30 min. After the reaction was complete, the mixture was allowed to stand and phase separated to obtain an organic phase containing Li and Ga, and an Al-containing raffinate. The aqueous phase was tested and calculated to have an extraction rate of 81.2% Li and 97.5% Ga, with a small amount of Al entrained. Extraction was performed at room temperature.

[0029] 5 mL of TBP loaded with Li and Ga was mixed with 10 mL of deionized water for 30 min. After the back-extraction, the mixture was allowed to stand for phase separation, and Li and Ga were almost completely back-extracted.

[0030] Step 2, Extraction-Back Extraction: 5 mL of a solution containing Li and Ga and 5 mL of [P 14,6,6,6 The mixture was mixed with HCl and the extraction time was 30 min. After extraction, the mixture was allowed to stand and separated into layers, and an extract containing Ga-loaded Aliquat 336 extractant and Li was obtained. The aqueous phase was tested by ICP-OES, and the Ga extraction rate was 97.2%, with almost no Li extraction, resulting in a Li concentration of 168 mg / L. In this example, the Li recovery rate was approximately 81%.

[0031] 5 mL of the above Ga-loaded [P 14,6,6,6 ]Cl was mixed with 10 mL of 0.1 mol / L H2SO4 solution and stripped at room temperature for 30 min. After stripping, the mixture was allowed to stand for phase separation, and the stripped solution was tested. The stripping rate of Ga was 92.1%, and a mixed solution of Fe and Ga was obtained.

[0032] Step 3, Extraction-Back Extraction: 5 mL of a solution containing Fe and Ga was mixed with 5 mL of 1 mol / L P507, the equilibrium pH adjusted to approximately 0.8, and the diluent was 260 ml sulfonated kerosene. After 30 min of extraction, the mixture was allowed to stand for phase separation, yielding Fe-loaded P507 and Ga-containing raffinate. The aqueous phase was tested, and the Fe removal rate reached 95.6%, with approximately 15% Ga entrained. The Ga concentration in the raffinate was 21 mg / L. In this example, the Ga recovery rate was approximately 66%.

[0033] 5 mL of the Fe-loaded P507 was mixed with 10 mL of 1 mol / L H2SO4 solution and stripped at room temperature for 30 min. After stripping, the mixture was allowed to stand for phase separation, and the aqueous phase was tested. The stripping rate of Fe was 90.3%.

[0034] [Example 3] The method for synergistic extraction of aluminum, lithium, and gallium from a high-aluminum solid waste acidic system comprises the following steps:

[0035] Step 1, Extraction-Back Extraction: High-aluminum gangue was acid-leached with hydrochloric acid and then solid-liquid separation yielded an acidic leachate containing 52.6 g / L Al, 4.8 g / L Fe, 195 mg / L Li, and 85 mg / L Ga. 10 mL of the acidic leachate was mixed with 10 mL of 2 mol / L TBP, diluted with dichloromethane, and the pH of the acidic leachate was adjusted to approximately 1. The reaction time was 5 min. After the reaction was complete, the mixture was allowed to stand and phase-separated to yield an organic phase containing Li, Fe, and Ga, and an Al-containing raffinate. The aqueous phase was tested and calculated to yield 97.2% Fe extraction, 78.9% Li extraction, and 97.5% Ga extraction, with a small amount of Al entrained. Extraction was performed at room temperature.

[0036] 5 mL of TBP loaded with Fe, Li, and Ga was mixed with 15 mL of 1 mol / L hydrochloric acid, and the back-extraction time was 60 min. After back-extraction, the mixture was allowed to stand and phase-separated, and Fe, Li, and Ga were almost completely back-extracted.

[0037] Step 2, Extraction-Back Extraction: 5 mL of the Fe, Li, Ga mixed solution in step 1 and 15 mL of [N 8,8,8,1 ]Cl was mixed, and the extraction time was 5 min. After extraction, the mixture was allowed to stand and separated into layers, obtaining an organic phase carrying Fe and Ga, and an extract containing Li. The aqueous phase was tested by ICP-OES, and the Fe extraction rate was 99.9%, the Ga extraction rate was 99.8%, and almost no Li was extracted. The Li concentration in the solution was 154 mg / L. In this example, the Li recovery rate was approximately 78%.

[0038] 5 mL of the organic phase containing Fe and Ga was mixed with 15 mL of 0.5 mol / L H2SO4 solution and stripped at room temperature for 60 minutes. After stripping, the mixture was allowed to stand for phase separation and the stripped solution was tested. The stripping rate of Fe was 89.3% and that of Ga was 95.2%, yielding a mixed Fe and Ga solution.

[0039] Step 3, Extraction-Back Extraction: 5 mL of the Fe and Ga mixed solution from step 2 was mixed with 15 mL of P507, and the diluent was 260 mL sulfonated kerosene. The equilibrium pH was controlled to approximately 0.8. After 40 minutes of extraction, the mixture was allowed to stand for phase separation, yielding Fe-loaded P507 and Ga-containing raffinate. The aqueous phase was tested, and the Fe removal rate reached 92.6%, with approximately 13% Ga entrained. The Ga concentration in the raffinate reached 64 mg / L. In this example, the Ga recovery rate was approximately 75%.

[0040] 5 mL of the Fe-loaded P507 was mixed with 15 mL of 1.0 mol / L H2SO4 solution and stripped at room temperature for 40 min. After stripping, the mixture was allowed to stand for phase separation, and the aqueous phase was tested. The stripping rate of Fe was 90.2%.

[0041] [Example 4] The method for synergistic extraction of aluminum, lithium, and gallium from a high-aluminum solid waste acidic system comprises the following steps:

[0042] Step 1, Extraction-Back Extraction: After acid leaching of fly ash with hydrochloric acid, solid-liquid separation was performed to obtain an acidic leachate containing 56.7 g / L Al, 5.1 g / L Fe, 202 mg / L Li, and 105 mg / L Ga. 30 mL of the acidic leachate was mixed with 10 mL of 2 mol / L TBP, diluented with dichloromethane, and the pH of the acidic leachate was adjusted to approximately 0. The reaction time was 20 min. After the reaction was completed, the mixture was allowed to stand for phase separation, yielding an organic phase containing Li, Fe, and Ga, and an Al-containing raffinate. The aqueous phase was tested and calculated to yield an extraction rate of 80.2% Fe, 76.9% Li, and 96.5% Ga, with a small amount of Al entrained. The extraction was performed at room temperature.

[0043] 5 mL of TBP loaded with Fe, Li, and Ga was mixed with 15 mL of 0.5 mol / L hydrochloric acid, and the back-extraction time was 60 min. After back-extraction, the mixture was allowed to stand and phase-separated, and Fe, Li, and Ga were almost completely back-extracted.

[0044] Step 2, Extraction-Back Extraction: 15 mL of the Fe, Li, and Ga mixed solution in step 1 and 5 mL of [N 8,8,8,1 ]Cl was mixed, and the extraction time was 20 min. After extraction, the mixture was allowed to stand and separated into layers, obtaining an organic phase carrying Fe and Ga, and an extract containing Li. The aqueous phase was tested by ICP-OES, and the Fe extraction rate was 99.3%, the Ga extraction rate was 96.2%, and almost no Li was extracted, with the Li concentration in the solution being 150 mg / L. In this example, the Li recovery rate was approximately 74%.

[0045] 5 mL of the organic phase containing Fe and Ga was mixed with 10 mL of 0.3 mol / L H2SO4 solution and stripped at room temperature for 60 minutes. After stripping, the mixture was allowed to stand for phase separation and the stripped solution was tested. The stripping rate of Fe was 85.4% and that of Ga was 93.5%, yielding a mixed Fe and Ga solution.

[0046] Step 3, Extraction-Back Extraction: 10 mL of the Fe and Ga mixed solution from step 2 was mixed with 3 mL of 1 mol / L P507, and the diluent was 260°C sulfonated kerosene. The equilibrium pH was controlled to approximately 0.8. After 60 minutes of extraction, the mixture was allowed to stand for phase separation, yielding Fe-loaded P507 and Ga-containing raffinate. The aqueous phase was tested, and the Fe removal rate reached 86.6%, with approximately 8% Ga entrained. The Ga concentration in the raffinate reached 75 mg / L. In this example, the Ga recovery rate was approximately 71%.

[0047] 5 mL of the Fe-loaded P507 was mixed with 10 mL of 3.0 mol / L H2SO4 solution and stripped at room temperature for 60 min. After stripping, the mixture was allowed to stand for phase separation, and the aqueous phase was tested. The stripping rate of Fe was 93.4%.

Claims

1. An acidic leachate of high-aluminum solid waste and an organic phase are mixed at a volume ratio of 1:3 to 3:1, and then extracted. After phase separation, an organic phase carrying Fe, Li, and Ga and an Al-containing raffinate are obtained. The acidic leachate is a solution obtained by leaching with hydrochloric acid, and the pH of the acidic leachate is 0 to 1. The organic phase contains an extractant and a diluent, and the extractant is tributyl phosphate. Step 1: Mixing the organic phase carrying Fe, Li, and Ga with hydrochloric acid in a volume ratio of 1:2 to 1:3 to perform back extraction, thereby obtaining an Fe, Li, and Ga mixed solution; The Fe, Li, and Ga mixed solution and an organic phase are mixed at a volume ratio of 1:3 to 3:1, and then extracted. After phase separation, an organic phase carrying Fe and Ga and a Li-containing raffinate are obtained, and the organic phase contains an extractant, which is a quaternary phosphonium salt or a quaternary ammonium salt; Step 2: Mixing the organic phase carrying Fe and Ga with sulfuric acid in a volume ratio of 1:2 to 1:3 and performing back extraction to obtain a mixed solution containing Fe and Ga; a mixed solution containing Fe and Ga and an organic phase are mixed at a volume ratio of 1:3 to 3:1, and then extracted to obtain an organic phase carrying Fe and a Ga-containing raffinate, the organic phase containing an extractant, the extractant being mono-2-ethylhexyl 2-ethylhexylphosphonate; Step 3: Mixing the organic phase carrying Fe with sulfuric acid in a volume ratio of 1:2 to 1:3 to perform back extraction to obtain an Fe solution; Including, A method for synergistically extracting aluminum, iron, lithium, and gallium from an acidic system of high-aluminum solid waste, comprising:

2. In step 1, the high-aluminum solid waste is a mixture of one or more of fly ash, gangue, and low-grade bauxite in any ratio, the extraction time is 5 to 30 minutes, and the back-extraction time is 30 to 60 minutes; 2. The method of claim 1 for synergistically extracting aluminum, iron, lithium, and gallium from a high-aluminum solid waste acidic system.

3. In step 1, the diluent is a mixture of one or more of 260# solvent oil, dichloromethane, chloroform, and 1,2-dichloroethane mixed in any ratio, and the concentration of the hydrochloric acid used in the stripping is 0 to 1 mol / L.

2. The method of claim 1 for synergistically extracting aluminum, iron, lithium, and gallium from a high-aluminum solid waste acidic system.

4. In step 2, the extraction time is 5 to 30 minutes, the stripping time is 30 to 60 minutes, and the sulfuric acid concentration is 0.1 to 0.5 mol / L.

2. The method of claim 1 for synergistically extracting aluminum, iron, lithium, and gallium from a high-aluminum solid waste acidic system.

5. In step 2, the organic phase further comprises a diluent, and in step 2, the diluent is a mixture of one or more of 260# solvent oil, dichloromethane, chloroform, and 1,2-dichloroethane in any ratio; 5. The method for synergistically extracting aluminum, iron, lithium, and gallium from a high-aluminum solid waste acidic system according to claim 4.

6. In step 3, the organic phase contains a diluent, and in step 3, the diluent is a mixture of one or more of 260# solvent oil, dichloromethane, chloroform, and 1,2-dichloroethane mixed in any ratio, and the sulfuric acid concentration is 1.0 to 4.0 mol / L; 2. The method of claim 1 for synergistically extracting aluminum, iron, lithium, and gallium from a high-aluminum solid waste acidic system.

7. In step 3, the extraction time is 30 to 60 minutes, and the back-extraction time is 30 to 60 minutes.

2. The method of claim 1 for synergistically extracting aluminum, iron, lithium, and gallium from a high-aluminum solid waste acidic system.

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