A method for removing aluminum from an iron-containing aluminum feed solution

Abstract

The present application relates to a kind of methods for removing aluminum from iron-containing aluminum feed liquid, and the present application relates to the field of hydrometallurgy, the method comprises: using saponifier saponification extractant, the saponifier is alkaline solution;Using saponified extractant to remove aluminum from the iron-containing aluminum feed liquid, control extraction equilibrium pH value is 0.5-3, obtain the raffinate removed aluminum and the aluminum extractant loaded;Aluminum-loaded extractant is sequentially washed and stripped, to obtain the extractant after stripping.The method of the present application has high aluminum extraction efficiency, so that iron and impurities such as aluminum are well separated.

Description

Technical Field

[0001] This invention relates to the field of hydrometallurgical technology. Specifically, this invention relates to a method for removing aluminum from molten iron-aluminum materials. Background Technology

[0002] Some leaching solutions with high iron content, such as waste lithium iron phosphate leaching solution, phosphorus iron slag leaching solution, and iron ore leaching solution, often contain aluminum. Separating and removing aluminum can better realize the resource recovery and utilization of iron in iron-aluminum leaching solutions.

[0003] Resin solid-phase extraction (SPE) utilizes resins containing specific functional groups to extract metals. SPE is characterized by good metal selectivity, rapid phase separation, simple operation, and environmental friendliness.

[0004] How to efficiently separate and remove aluminum from molten iron-containing aluminum feedstock has become an urgent problem that related industries need to solve. Summary of the Invention

[0005] One object of the present invention is to provide a method for efficiently removing aluminum from an iron-aluminum molten material.

[0006] Therefore, the present invention provides a method for removing aluminum from an iron-aluminum molten material, comprising the following steps:

[0007] S1. The extractant is saponified using a saponifying agent, wherein the saponifying agent is an alkaline solution;

[0008] S2. The iron-aluminum-containing liquid is extracted with a saponified extractant to remove aluminum, and the extraction equilibrium pH is controlled at 0.5-3 to obtain the aluminum-removed raffinate and the aluminum-loaded extractant.

[0009] S3. The aluminum-loaded extractant is washed and back-extracted sequentially to obtain the back-extracted extractant.

[0010] In molten aluminum containing iron, iron mainly exists in the form of ferrous iron.

[0011] in,

[0012] The extractant comprises a chelating resin of formula (I):

[0013]

[0014] in:

[0015] M is the base resin;

[0016] R1 and R2 are each independently hydrogen, phosphorus-containing groups, carboxyl groups or their derivatives;

[0017] At least one of R1 and R2 is a phosphorus-containing group.

[0018] The method of this invention has high aluminum extraction efficiency, resulting in good separation of iron from aluminum impurities. Detailed Implementation

[0019] The various aspects of the invention, as well as further objects, features and advantages, will be set forth more fully below.

[0020] As described above, the present invention provides a method for removing aluminum from an iron-aluminum molten material, comprising the following steps:

[0021] S1. The extractant is saponified using a saponifying agent, wherein the saponifying agent is an alkaline solution;

[0022] S2. The iron-aluminum-containing liquid is extracted with a saponified extractant to remove aluminum, and the extraction equilibrium pH is controlled at 0.5-3 to obtain the aluminum-removed raffinate and the aluminum-loaded extractant.

[0023] S3. The aluminum-loaded extractant is washed and back-extracted sequentially to obtain the back-extracted extractant.

[0024] The iron in the iron-containing aluminum molten material mainly exists in the form of divalent iron.

[0025] in,

[0026] The extractant comprises a chelating resin of formula (I):

[0027]

[0028] in:

[0029] M is the base resin;

[0030] R1 and R2 are each independently hydrogen, phosphorus-containing groups, carboxyl groups or their derivatives;

[0031] At least one of R1 and R2 is a phosphorus-containing group.

[0032] In this invention, the extraction equilibrium pH is controlled at 0.5-3, within which the aluminum extraction rate is high. Preferably, the extraction equilibrium pH is controlled at 0.8-2.8, and more preferably at 1-2.

[0033] Preferably, one of R1 and R2 is a phosphorus-containing group, and the other is a carboxyl group or a derivative thereof.

[0034] The saponifying agent described in this invention is not particularly limited, but preferably it is selected from one or a combination of at least two of ammonia, sodium hydroxide solution, sodium carbonate and potassium hydroxide solution, and more preferably it is ammonia.

[0035] Preferably, the concentrations of the ammonia solution, sodium hydroxide solution, sodium carbonate solution, and potassium hydroxide solution are 0.1-10 mol / L, more preferably 0.2-2 mol / L.

[0036] The saponified solution can be recycled for saponification and / or preparation of saponifying agents.

[0037] Furthermore, the pH of the solution after saponification is controlled to be 4-10, preferably 4-7, or the saponified extractant is washed with pure water before extraction, and the pH of the washing effluent is controlled to be 4-10. Under these conditions, the extraction and separation effect of aluminum is particularly good, and the process cost is low.

[0038] The iron-aluminum molten material can be, for example, an aqueous dispersion or an aqueous solution.

[0039] Advantageously, the iron-aluminum molten material contains Al 0.02-16 g / L, preferably Al 0.1-10 g / L, by weight relative to the volume of the iron-aluminum molten material.

[0040] In some embodiments, the iron-aluminum molten material contains 1-120 g / L of Fe, preferably 40-80 g / L, by weight relative to the volume of the iron-aluminum molten material.

[0041] In some embodiments, the pH value of the iron-aluminum-containing liquid is 0.2-2.5, preferably, the pH value of the iron-aluminum-containing liquid is greater than or equal to 0.5 and less than 2.

[0042] The iron in the iron-containing aluminum molten material mainly exists in the form of divalent iron, which means that divalent iron accounts for more than 95% of the total iron weight.

[0043] In some embodiments, the iron-aluminum molten material contains ferric iron. In the case where the iron-aluminum molten material contains ferric iron, preferably, a reducing agent is used to reduce the ferric iron in the iron-aluminum molten material.

[0044] The reducing agent is not particularly limited, but preferably includes one or a combination of at least two of the following: iron powder, nickel-iron alloy, sodium sulfite, sodium thiosulfate, ascorbic acid, glucose, and fructose.

[0045] In some embodiments, the iron-aluminum molten material may optionally include other elements, such as one or a combination of at least two of Zn, Cd, Cu, Mg, Ni, Co, Ti, Li, Mn, Cr, Na, P, etc.

[0046] This invention does not specifically limit the base resin M. Preferably, the base resin M is selected from polystyrene resin, copolymer of styrene and divinylbenzene, phenolic resin polymer, polyacrylic acid resin, or silicone resin. More preferably, the base resin M is selected from polystyrene resin or copolymer of styrene and divinylbenzene.

[0047] More specifically, the phosphorus-containing groups referred to in relation to R1 and R2 are selected from the following groups:

[0048]

[0049] The carboxyl group or its derivative thereof for R1 and R2 is selected from the following groups:

[0050] Where * represents the connection site between the group and the base resin.

[0051] More specifically, the chelating resin of formula (I) has a structure selected from the following:

[0052]

[0053]

[0054] M is independently selected from polystyrene resin, copolymers of styrene and divinylbenzene, phenolic resin polymers, polyacrylic resins, or silicone resins.

[0055] More preferably, the chelating resin of formula (I) has a structure selected from the following:

[0056]

[0057] M is independently selected from polystyrene resin or copolymers of styrene and divinylbenzene.

[0058] In some implementations, the saponified extractant may contain a portion of the saponifying agent. Preferably, the saponified extractant is washed before extraction to remove the entrained saponifying agent, thus obtaining the dead volume of the saponified solution.

[0059] Furthermore, before extraction, the saponified extractant is washed with the iron-aluminum-containing liquid. Preferably, the volume of the iron-aluminum-containing liquid used for washing before extraction is 0.5-1.5 Bv.

[0060] Furthermore, the extraction flow rate is controlled at 0.5–20 Bv / h, preferably 1–5 Bv / h.

[0061] Furthermore, the volume of the iron-aluminum-containing liquid in the extraction is 1-20 Bv.

[0062] Furthermore, the washing liquid used in the washing process can be, for example, one or a combination of at least two of the following: water, acid solution, and dead volume of the solution after saponification; the pH value of the acid solution is 1-6, preferably 1-3, and the acid solution is not particularly limited, including hydrochloric acid and / or sulfuric acid, preferably sulfuric acid solution.

[0063] Preferably, the washing process can be divided into a first-stage washing and a second-stage washing, resulting in a solution after the first-stage washing and a solution after the second-stage washing, respectively.

[0064] The washing flow rate is controlled at 1-40 Bv / h, preferably 2-10 Bv / h, and the volume of the washing liquid is controlled at 0.5-3.0 Bv, preferably 0.5-1 Bv.

[0065] The flow rate of the second-stage washing is controlled at 1-20 Bv / h, preferably 1-5 Bv / h, and the volume of the second-stage washing liquid is controlled at 1-5 Bv, preferably 1-2 Bv.

[0066] In some embodiments, the washing solution is the dead volume of the solution after saponification; the washing solution is incorporated into the iron-aluminum slurry or used as the leachate in the leaching section for preparing the iron-aluminum slurry.

[0067] In some embodiments, the two-stage washing solution is selected from one or a combination of two of water and the acid solution.

[0068] In some embodiments, the washed aluminum-loaded extractant is further back-extracted using a back-extracting agent to obtain a back-extracted extractant.

[0069] Furthermore, the back-extraction agent used includes one or a combination of at least two of sulfuric acid, hydrochloric acid, and phosphoric acid solutions, preferably a sulfuric acid solution, wherein the sulfuric acid, hydrochloric acid, and phosphoric acid solutions contain H+. + The concentration is 0.8-12 mol / L, preferably 1-4 mol / L.

[0070] Furthermore, the volume of the back-extraction agent is 0.5-5 Bv, preferably 0.5-2 Bv, the back-extraction flow rate is 5-25 Bv / h, preferably 15-25 Bv / h, and the cyclic back-extraction time is 2-6 h, preferably 2-4 h.

[0071] The back-extraction also yields a back-extraction liquid, which can be recycled for further back-extraction.

[0072] Furthermore, the extractant after back-extraction is regenerated and recycled. The regeneration solution used for regeneration is not particularly limited and can be one or a combination of two of water and acid. The acid solution is not particularly limited and includes hydrochloric acid and / or sulfuric acid solution, preferably sulfuric acid solution, and preferably the pH value of the acid solution is 1-3.

[0073] The water may be selected from one or a combination of at least two of pure water, tap water, and soft water.

[0074] Preferably, the pH of the regenerated solution is controlled to be 0.5-2, more preferably 1-1.5.

[0075] Preferably, the volume of the regenerant is 0.5-8 Bv, more preferably 0.5-5 Bv; the regeneration flow rate is 0.5-10 Bv / h, more preferably 1-10 Bv / h.

[0076] The regenerated solution can be recycled for further regeneration.

[0077] The method of this invention can efficiently remove aluminum from iron-containing solutions, thereby purifying the iron-containing solutions. It achieves good separation of aluminum and iron, is simple to operate, and has low process cost.

[0078] The method provided by this invention can achieve an aluminum content of ≤0.02g / L and an iron loss rate of ≤7% in the raffinate.

[0079] Furthermore, the resin used in the method of the present invention can be reused after back-extraction and regeneration, resulting in low operating costs and good economic benefits.

[0080] In this application, the term "and / or" covers situations involving one or both of the mentioned elements.

[0081] In this application, the terms "comprising" and "including" cover situations where other elements not explicitly mentioned are also included, as well as situations where the mentioned elements constitute the entirety of the application.

[0082] Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. In the event of any discrepancy between the definitions of terms in this specification and their commonly understood meaning by one of ordinary skill in the art to which this invention pertains, the definitions set forth herein shall prevail.

[0083] Unless otherwise stated, all numerical values ​​for the amount of ingredients, temperature, time, etc., used in the specification and claims are to be understood as being modified by the term "about". Therefore, unless otherwise indicated, the numerical parameters set forth herein are approximate values ​​that can be varied to obtain the desired performance.

[0084] Example

[0085] The following will further illustrate the concept, specific structure, and technical effects of the present invention with reference to embodiments, so as to enable those skilled in the art to fully understand the purpose, features, and effects of the present invention. It will be readily understood by those skilled in the art that the embodiments described herein are merely illustrative, and the scope of the present invention is not limited thereto.

[0086] Example 1

[0087] Nickel-iron alloy powder was used to reduce an initial iron-aluminum slurry containing ferric iron. The amount of nickel-iron alloy added was greater than 1 times the molar amount of ferric iron in the initial iron-aluminum slurry, based on the molar amount of ferric iron. After filtration, an iron-aluminum slurry with ferrous iron accounting for 99.9% of the total iron content was obtained. The pH value of this slurry was 1.5, and it contained the following metallic components:

[0088] element Al Ca Cd Co Cr Cu Fe Content (g / L) 0.3 0.2 0.001 0.005 0.001 0.001 70.15 element Li Mg Mn Na Ni Zn Ti Content (g / L) 0.005 0.445 0.314 0.214 2 0.001 0.1

[0089] Select a chelating resin (structural formula: Wherein, M is polystyrene resin microspheres) is used as the aluminum extraction agent.

[0090] The chelating resin was loaded into a resin column (400 mL resin = 1 Bv). The chelating resin was saponified using a saponifying agent, ammonia water with a concentration of 0.53 mol / L and a saponifying agent dosage of 1.25 Bv. The saponification flow rate was 10 Bv / h. The resulting saponified solution was circulated for further saponification for 2 hours. After saponification, the chelating resin and the saponified solution with a pH of 6.58 were obtained.

[0091] The iron-aluminum-containing solution was extracted using a saponified chelating resin. The solution volume was 4.375 Bv, the extraction flow rate was 2.25 Bv / h, and the pH of the extraction equilibrium (outlet raffinate) was controlled at 2.6. This yielded 0.5 Bv of saponified solution dead volume, 3.875 Bv of raffinate, and aluminum-loaded chelating resin.

[0092] The loaded aluminum chelate resin was subjected to a two-stage washing process. 0.5 Bv of the dead volume of the solution after saponification was selected as the first-stage washing solution, and 1 Bv of pure water was selected as the second-stage washing solution. The flow rate for both stages was controlled at 3 Bv / h to obtain the washed loaded aluminum chelate resin. 1.25 Bv of pure water was then used as the second-stage washing solution. + The washed aluminum-loaded chelating resin was back-extracted using a 2.0 mol / L sulfuric acid solution at a flow rate of 10 Bv / h. The resulting back-extracted solution was recycled for further back-extraction for 3 hours. After back-extraction, the back-extracted chelating resin was obtained. Subsequently, the back-extracted chelating resin was regenerated using a sulfuric acid solution with a pH of 2 at a flow rate of 3 Bv / h, resulting in regenerated chelating resin and a regenerated solution with a pH of 1.0. The regenerated chelating resin was then recycled.

[0093] In this embodiment, the aluminum and iron contents in the raffinate are 0.0168 g / L and 65.8 g / L, respectively, and the resulting back-extraction solution contains 0.85 g / L aluminum and 1.44 g / L iron.

[0094] Example 2

[0095] An initial iron-aluminum solution containing ferric iron (Fe3+) was reduced using iron powder and ascorbic acid. The total amount of iron powder and ascorbic acid added was based on the molar amount of ferric iron in the initial iron-aluminum solution, and the total amount added was greater than 1 times the molar amount of ferric iron in the initial iron-aluminum solution. After filtration, an iron-aluminum solution with ferrous iron (Fe2+) accounting for nearly 100% of the total iron content was obtained. The pH value of this solution was 1.5, and it contained the following metallic components:

[0096] element Al Ca Cd Co Cr Cu Fe P Content (g / L) 0.40 0.2 0.001 0.001 0.001 0.50 68.52 32.5 element Li Mg Mn Na Ni Zn Ti Content (g / L) 6.69 0.50 0.04 0.12 0.2 0.001 0.50

[0097] Select a chelating resin (structural formula: Wherein, M is polystyrene resin microspheres) is used as the aluminum extraction agent.

[0098] The chelating resin was loaded into a resin column (400 mL resin = 1 Bv). The chelating resin was saponified using a saponifying agent, ammonia water with a concentration of 2 mol / L, a saponifying agent dosage of 1.69 Bv, and a saponification flow rate of 5 Bv / h. The resulting saponified solution was circulated for further saponification over a period of 3 hours. Once saponification was complete, the saponified chelating resin was obtained.

[0099] The iron-aluminum-containing solution was extracted using a saponified chelating resin. The solution volume was 5 Bv, the extraction flow rate was 3 Bv / h, and the pH of the extraction equilibrium (outlet raffinate) was controlled at 2.8. This yielded 1 Bv of dead volume of the saponified solution, 4 Bv of raffinate, and aluminum-loaded chelating resin.

[0100] The loaded aluminum chelate resin was subjected to a two-stage washing process. 1 Bv of the dead volume of the solution after saponification was used as the first-stage washing solution, and 1 Bv of sulfuric acid solution with pH 3 was used as the second-stage washing solution. The flow rate for both stages was controlled at 2 Bv / h to obtain the washed loaded aluminum chelate resin. 2.5 Bv of H... + The washed aluminum-loaded chelating resin was back-extracted using a 1.0 mol / L sulfuric acid solution at a flow rate of 5 Bv / h. The resulting back-extracted solution was recycled for further back-extraction for 2.5 h. After back-extraction, the back-extracted chelating resin was obtained. The back-extracted chelating resin was then regenerated using a sulfuric acid solution with a pH of 3 at a flow rate of 5 Bv / h. The pH of the regenerated solution was controlled to be 2, resulting in regenerated chelating resin, which was then recycled.

[0101] In this embodiment, the aluminum and iron contents in the raffinate are 0.0145 g / L and 63.85 g / L, respectively, and the resulting back-extraction solution contains 0.7 g / L aluminum and 0.8 g / L iron.

[0102] Example 3

[0103] The feed solution in this embodiment is an iron-aluminum feed solution with a pH value of 1.1. It contains Al 8.0 g / L, P 33 g / L, and iron 64 g / L, of which divalent iron accounts for nearly 100% of the total iron.

[0104] Select a chelating resin (structural formula: Wherein, M is a copolymer of styrene and divinylbenzene) is used as an aluminum extraction agent.

[0105] The chelating resin was mixed with a saponifying agent and stirred for saponification. The saponifying agent was a 4 mol / L sodium hydroxide solution. Solid-liquid separation was performed to obtain the saponified extractant.

[0106] The iron-aluminum-containing liquid was subjected to four-stage stirring extraction using a saponified extractant. The ratio of the saponified extractant to the iron-aluminum-containing liquid was 1 g: 3 mL, and the extraction time for each stage was 0.5 h. The pH value of the extraction equilibrium (outlet raffinate) was controlled at 2.0 to obtain the raffinate and the aluminum-loaded extractant.

[0107] The aluminum-loaded extractant was subjected to five stages of agitation and washing. A sulfuric acid solution with a pH of 2.5 was used as the washing solution, and the ratio of aluminum-loaded extractant to washing solution was 1 g: 2 ml. Each washing stage lasted 0.5 h, yielding the washed aluminum-loaded extractant. H... + A 2.5 mol / L sulfuric acid solution was used to perform four-stage back-extraction on the washed aluminum-loaded extractant, with the back-extraction time controlled at 0.5 h. The washed aluminum-loaded extractant was then reacted with H2O. + The ratio of 2.5 mol / L sulfuric acid solution to 1 g: 1 mL is used to obtain the back-extraction solution and the back-extraction extractant. The back-extraction extractant is pre-washed with pure water at a liquid-to-solid ratio of 1 mL: 1 g. Then, the pre-washed back-extraction extractant is stirred and regenerated using sulfuric acid solution with a pH of 2. The pH of the regenerated solution is controlled to be 1.1 to obtain the regenerated extractant, which is then recycled.

[0108] In this embodiment, the aluminum and iron contents in the raffinate are 0.011 g / L and 59.76 g / L, respectively, and the resulting back-extraction solution contains 20.5 g / L aluminum and 1.3 g / L iron.

[0109] Example 4

[0110] The feed solution in this embodiment is an iron-aluminum feed solution with a pH value of 0.5, containing 2.5 g / L of Al and 73.5 g / L of iron, with ferrous iron accounting for 99.9% of the total iron content.

[0111] Select an extractant (structural formula: Wherein, M is a copolymer of styrene and divinylbenzene) is used as an aluminum extraction agent.

[0112] The extractant and saponifying agent are mixed and stirred for saponification. The saponifying agent is a 0.2 mol / L sodium hydroxide solution. Solid-liquid separation is performed to obtain the saponified extractant.

[0113] The iron-aluminum-containing liquid was subjected to three-stage stirring extraction using a saponified extractant. The ratio of the saponified extractant to the iron-aluminum-containing liquid was 1 g: 5 mL, and the extraction time for each stage was 0.5 h. The pH value of the extraction equilibrium (outlet raffinate) was controlled at 0.8 to obtain the raffinate and the aluminum-loaded extractant.

[0114] The aluminum-loaded extractant was subjected to five stages of agitation and washing, using a sulfuric acid solution with a pH of 3 as the washing liquid. The ratio of aluminum-loaded extractant to washing liquid was 1 g: 2 mL, and the washing time for each stage was controlled to be 0.5 h, resulting in the washed aluminum-loaded extractant. H... + A 3 mol / L sulfuric acid solution was used to perform three-stage back-extraction on the washed aluminum-loaded extractant, with the back-extraction time controlled at 0.5 h. The washed aluminum-loaded extractant was then reacted with H2O. + The ratio of 1.5 mol / L sulfuric acid solution to 1 g: 2 mL is used to obtain the back-extraction solution and the back-extraction extractant. Then, the back-extraction extractant is regenerated by stirring with sulfuric acid solution with a pH of 3, and the pH of the regenerated solution is controlled to be 2.5 to obtain the regenerated extractant, which is then recycled.

[0115] In this embodiment, the aluminum and iron contents in the raffinate are 0.02 g / L and 69.5 g / L, respectively, and the resulting back-extraction solution contains 3.4 g / L aluminum and 0.9 g / L iron.

[0116] Example 5

[0117] The steps are the same as in Example 3, except that the pH value of the iron-aluminum-containing feed solution is adjusted with ammonia water to control the pH value of the extraction equilibrium (outlet raffinate) to be 2.7. In this example, the aluminum and iron contents in the raffinate are 0.01 g / L and 59.7 g / L, respectively, and the resulting back-extraction solution contains 21.0 g / L of aluminum and 1.3 g / L of iron.

[0118] Example 6

[0119] The steps are the same as in Example 5, except that the extractant (structural formula is...) is selected. Wherein, M is a copolymer of styrene and divinylbenzene) is used as the aluminum extraction extractant, and the pH value of the extraction equilibrium (outlet raffinate) is controlled at 2.7. In this embodiment, the aluminum and iron contents in the raffinate are 0.01 g / L and 59.7 g / L, respectively, and the resulting back-extraction liquid contains 19.0 g / L of aluminum and 1.25 g / L of iron.

[0120] Example 7

[0121] The steps are the same as in Example 3, except that sulfuric acid is used to adjust the pH of the iron-aluminum-containing feed solution to control the pH of the extraction equilibrium (outlet raffinate) to 1.5. In this example, the aluminum and iron contents in the raffinate are 0.021 g / L and 59.8 g / L, respectively, and the resulting back-extraction solution contains 19.5 g / L of aluminum and 1.27 g / L of iron.

[0122] Comparative Example 1

[0123] The steps are the same as in Example 1, except that the chelating resin is not saponified and is directly used to extract the iron-aluminum-containing liquid. The resulting raffinate has a pH of 1.35. The aluminum and iron contents in the raffinate of this comparative example are 0.24 g / L and 65.7 g / L, respectively. The resulting back-extracted liquid contains 0.05 g / L of aluminum and 1.5 g / L of iron.

[0124] Comparative Example 2

[0125] The steps are the same as in Example 3, except that the aluminum extraction agent has the following structural formula: The volume fraction was 25%, the diluent was Escaid110, and the pH of the extraction equilibrium (outlet raffinate) was controlled at 2.0. The results showed that the aluminum and iron contents in the raffinate were 7.76 g / L and 62.2 g / L, respectively, and the back-extraction solution contained 0.68 g / L of aluminum and 1.4 g / L of iron.

[0126] Comparative Example 3

[0127] The steps are the same as in Example 1, except that the aluminum extraction agent is... The pH of the extraction equilibrium (outlet raffinate) was controlled at 2.6. The results showed that the aluminum and iron contents in the raffinate were 0.1 g / L and 65.6 g / L, respectively, and the back-extraction solution contained 0.6 g / L of aluminum and 1.46 g / L of iron.

[0128] Comparative Example 4

[0129] The steps are the same as in Example 5, except that the aluminum extraction extractant is P204 (di(2-ethylhexyl) phosphate) with a volume fraction of 20%, the diluent is sulfonated kerosene, and the pH of the extraction equilibrium (outlet raffinate) is controlled at 2.7. The results show that the aluminum and iron contents in the raffinate are 0.62 g / L and 62.5 g / L, respectively, and the back-extraction solution contains 17.5 g / L of aluminum and 1.32 g / L of iron.

[0130] The foregoing descriptions are merely exemplary embodiments or examples of the present invention and are not intended to limit the invention. Those skilled in the art will recognize that the present invention can be modified and varied in many ways. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principle of the present invention are included within the scope of the claims of this application.

Claims

1. A method for removing aluminum from an iron-aluminum molten material, characterized in that, Includes the following steps: S1. The extractant is saponified using a saponifying agent, wherein the saponifying agent is an alkaline solution; S2. The iron-aluminum-containing liquid is extracted with a saponified extractant to remove aluminum, and the extraction equilibrium pH is controlled at 1.5-2.8 to obtain the aluminum-removed raffinate and the aluminum-loaded extractant. S3. The aluminum-loaded extractant is washed and back-extracted sequentially to obtain the back-extracted extractant. The iron in the iron-containing aluminum molten material mainly exists in the form of divalent iron. in, The extractant comprises a chelating resin of formula (I): (I)， in: M is the base resin; R1 is , R2 is a carboxyl group or a derivative thereof; The carboxyl group or its derivative is selected from the following groups: , , , , , , , in These are the sites where the functional groups connect to the base resin.

2. The method according to claim 1, characterized in that, The saponifying agent is selected from any one or a combination of at least two of ammonia water, sodium hydroxide solution, sodium carbonate solution, and potassium hydroxide solution.

3. The method according to claim 2, characterized in that, The concentrations of the ammonia solution, sodium hydroxide solution, sodium carbonate solution, and potassium hydroxide solution are 0.1-10 mol / L; Control the pH of the solution after saponification to 4-10, or wash the saponified extractant with pure water before extraction and control the pH of the washing effluent to 4-10.

4. The method according to claim 3, characterized in that, The concentrations of the ammonia solution, sodium hydroxide solution, sodium carbonate solution, and potassium hydroxide solution are 0.2-2 mol / L.

5. The method according to claim 1, characterized in that, The iron-aluminum molten material contains Al 0.02-16 g / L, by weight relative to the volume of the iron-aluminum molten material; The iron-aluminum molten material contains 1-120 g / L of Fe, by weight relative to the volume of the iron-aluminum molten material.

6. The method according to claim 1, characterized in that, The iron-aluminum molten material also contains ferric iron, and the method further includes using a reducing agent to reduce the ferric iron in the iron-aluminum molten material.

7. The method according to claim 1, characterized in that, The base resin M is selected from polystyrene resin, copolymer of styrene and divinylbenzene, phenolic resin polymer, polyacrylic resin or silicone resin.

8. The method according to claim 1, characterized in that, The chelating resin of formula (I) has a structure selected from the following: 、 、 、 、 ， M is independently selected from polystyrene resin, copolymer of styrene and divinylbenzene, phenolic resin polymer, polyacrylic resin or silicone resin.

9. The method according to claim 1, characterized in that, Before extraction, the saponified extractant is washed to remove the saponifying agent entrained therein, resulting in a saponifying agent washing solution; before extraction, the saponified extractant is washed with the iron-aluminum-containing material solution.

10. The method according to claim 9, characterized in that, The volume of the iron-aluminum-containing liquid used for washing before extraction is 0.5-1.5 Bv.

11. The method according to claim 1, characterized in that, The extraction flow rate is controlled at 0.5-20 Bv / h during the extraction process; The washing solution used is one or a combination of at least two of the following: water, acid solution, and saponifying agent washing solution obtained by washing the saponified extractant before extraction; the acid solution has a pH value of 1-6 and includes hydrochloric acid and / or sulfuric acid solution.

12. The method according to claim 11, characterized in that, The extraction flow rate is 1-5 Bv / h.

13. The method according to claim 1, characterized in that, The volume of the iron-aluminum-containing liquid in the extraction process is 1-20 Bv.

14. The method according to claim 11, characterized in that, The pH value of the acid solution is 1-3.

15. The method according to claim 11, characterized in that, The acid solution is a sulfuric acid solution.

16. The method according to claim 1, characterized in that, The washing process is divided into a first-stage washing and a second-stage washing, resulting in solutions after the first-stage washing and solutions after the second-stage washing, respectively. The washing flow rate of the first stage is controlled at 1-40 Bv / h, and the volume of the washing liquid in the first stage is controlled at 0.5-3.0 Bv. The flow rate of the second-stage washing is controlled at 1-20 Bv / h, and the volume of the second-stage washing liquid is controlled at 1-5 Bv. The washing solution mentioned above is a saponifying agent washing solution obtained by washing the saponified extractant before extraction. The two-stage washing solution is selected from one or a combination of two of water and acid solutions.

17. The method according to claim 16, characterized in that, Control the washing flow rate of one stage to 2-10 Bv / h, and control the volume of the washing liquid of one stage to 0.5-1 Bv.

18. The method according to claim 16, characterized in that, The flow rate of the second-stage washing is controlled at 1-5 Bv / h, and the volume of the second-stage washing liquid is controlled at 1-2 Bv.

19. The method according to claim 1, characterized in that, The washed aluminum-loaded extractant obtained from washing is back-extracted using a back-extracting agent to obtain a back-extracted extractant.

20. The method according to claim 19, characterized in that, The stripping agent comprises one or a combination of at least two of sulfuric acid, hydrochloric acid, and phosphoric acid solution, wherein the sulfuric acid, hydrochloric acid, and phosphoric acid solution contain H... + The concentration is 0.8-12 mol / L.

21. The method according to claim 20, characterized in that, The sulfuric acid, hydrochloric acid, and phosphoric acid solutions contain H... + The concentration is 1-4 mol / L.

22. The method according to claim 19, characterized in that, The back-extraction also yields a back-extraction liquid, which is recycled for further back-extraction. The extractant after back-extraction is regenerated and reused. The pH of the regenerated solution should be controlled to be 0.5-2.

23. The method according to claim 22, characterized in that, The pH of the regenerated solution should be controlled to be 1-1.5.

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