Use and method for the extraction and separation of indium with amine-containing neutral phosphine extractants

Abstract

The present application relates to the use and method of extracting and separating indium by amine group-containing neutral phosphine extractant of general formula I, wherein R1 and R2 are each independently selected from C1-C 12 alkyl; R3, R4, R5 and R6 are each independently selected from C 1‑10 alkyl and hydrogen; R7 and R8 are each independently selected from C 1‑16 alkyl and hydrogen. The amine group-containing neutral phosphine extractant used in the present application has good effect of extracting and separating indium, stable property, easy to synthesize, simple and readily available raw materials for synthesis, and low cost, thereby effectively reducing the cost of extracting and separating indium, and having high industrial application value.

Description

TECHNICAL FIELD

[0001] The present application relates to a method for extracting and separating indium, in particular, to the use and method of a kind of amido neutral phosphine extractant for extracting and separating indium. BACKGROUND

[0002] Indium is widely used in high-tech and energy, information, aerospace, electronic industry and medical fields due to its good light penetration and strong conductivity. Indium is dispersed in the earth's crust, mainly associated with gallium, zinc and other elements in sphalerite (the content of indium is 0.005%) and lead-zinc ore. Therefore, indium is often recovered as a byproduct from zinc smelting waste residue. Since indium has similar chemical properties to gallium and zinc, its separation is often difficult.

[0003] Solvent extraction separation method has become one of the main methods for extracting and recovering indium from acidic solution due to its advantages of large treatment capacity, fast reaction speed and good separation effect. Currently, the main extractants for industrial extraction and separation of indium include acid phosphorus extractant, hydroxylamine extractant, carboxylic acid extractant and amine extractant, etc.

[0004] For example, CN113122736A discloses a method for recovering indium from sulfuric acid solution using acid phosphorus extractant P204, CN104962743A discloses a method for selectively extracting indium and gallium from zinc displacement residue sulfuric acid leaching solution after recovering germanium using a synergistic extraction system composed of hydroxylamine chelating extractant and carboxylic acid extractant, and Gaoyuan et al. (Extraction and separation of indium by N503 in hydrochloric acid system, Non-ferrous metals (smelting part), 2012 (01): 35-38) found that amine extractant N503 is suitable for extracting indium under relatively low acidity conditions and realizing separation from other metal elements.

[0005] However, acid phosphorus (phosphine) extractants P204 and P507 have poor selectivity for indium, gallium and zinc; hydroxylamine extractants have complicated synthesis steps, high price (market price is 140 million / ton), and long equilibrium time for indium extraction; carboxylic acid extractants and amine extractants are easily emulsified under low acidity conditions, and have too high water solubility, causing high COD of water body, additional water treatment cost, and the need for regular replenishment of extractants.

[0006] Therefore, it is of great significance to find a new type of extractant with high selectivity, low cost and stability for efficient recovery and utilization of indium. SUMMARY

[0007] In order to solve the above problems, the present application uses a new type of amido neutral phosphine extractant to extract and separate indium, which achieves good extraction and separation effect, and the extractant used is stable and easy to synthesize.

[0008] It is an object of the present application to provide the use of an amine group-containing neutral phosphine extractant for the extraction and separation of indium.

[0009] It is another object of the present application to provide a method for the extraction and separation of indium using the amine group-containing neutral phosphine extractant.

[0010] One aspect of the present application provides the use of an amine group-containing neutral phosphine extractant of the following general formula I for the extraction and separation of indium:

[0011]

[0012] wherein,

[0013] R1and R2are each independently selected from C1-C 12 alkyl;

[0014] R3, R4, R5and R6are each independently selected from C 1-10 alkyl and hydrogen;

[0015] R7and R8are each independently selected from C 1-16 alkyl and hydrogen.

[0016] Another aspect of the present application relates to a method for the extraction and separation of indium, which comprises the step of using an amine group-containing neutral phosphine extractant of general formula I to extract an indium-containing feed solution to separate indium.

[0017] The method for the separation of indium according to the present application can be carried out by a method of solvent extraction, for example, the amine group-containing neutral phosphine extractant of the present application is formulated into a liquid extraction system for use, or by a method of solid-liquid extraction, for example, the amine group-containing neutral phosphine extractant of the present application is formulated into a solid-state separation material such as an extraction resin for use.

[0018] Advantages

[0019] The amine group-containing neutral phosphine extractant used in the present application not only has good extraction and separation capacity for indium, but also has a simple synthesis method, simple and readily available chemical raw materials used in the synthesis, and low cost, thereby effectively reducing the extraction and separation cost of indium and having high industrial application value. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 A graph showing the relationship between the extraction rate of indium, gallium and zinc extracted by 2-((2-ethylhexyl)amino)-ethyl phosphonic acid di(2-ethylhexyl) ester in Extraction Example 1 and the concentration of sulfuric acid;

[0021] Figure 2 A graph showing the relationship between the extraction rate of indium, gallium and zinc extracted by (2-ethylhexyl)aminomethyl phosphonic acid di(2-ethylhexyl) ester in Comparative Extraction Example 1 and the concentration of sulfuric acid. DETAILED DESCRIPTION

[0022] The present application will be described in more detail below, but the present application is not limited to the following.

[0023] The present application provides, in one aspect, the use of an amine group containing neutral phosphine extractant of general formula I for the extraction separation of indium:

[0024]

[0025] wherein,

[0026] R1and R2are each independently selected from the group consisting of C1-C 12 alkyl, preferably C4-C 10 alkyl, more preferably C5-C9alkyl, most preferably C6-C8alkyl;

[0027] R3, R4, R5and R6are each independently selected from the group consisting of C 1-10 alkyl and hydrogen;

[0028] R7and R8are each independently selected from the group consisting of C 1-16 alkyl and hydrogen.

[0029] In the general formula I, R1and R2are the same or different. Preferably, the total number of carbon atoms of R1and R2is an integer between 8 and 20, preferably an integer between 10 and 18, for example 11, 12, 13, 14, 15, 16, 17, etc. Furthermore, R1and R2are preferably the same alkyl, more preferably the same C5-C9alkyl.

[0030] R3, R4, R5and R6are the same or different; preferably, R3, R4, R5and R6are selected from the group consisting of C1-C8alkyl and hydrogen, preferably C1-C5alkyl and hydrogen, more preferably C1-C3alkyl and hydrogen; preferably, the total number of carbon atoms of R3, R4, R5and R6is an integer between 0 and 32, preferably an integer between 0 and 20, for example 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, etc.; preferably, one of R3and R4is H and one of R5and R6is H.

[0031] R7and R8are the same or different; preferably, R7is selected from the group consisting of C1-C 10 alkyl and hydrogen, preferably C1-C8alkyl and hydrogen, and R8is selected from the group consisting of C1-C 14 alkyl, preferably C1-C 12 alkyl; preferably, the total number of carbon atoms of R7and R8is an integer between 1 and 16, preferably an integer between 2 and 13; more preferably an integer between 3 and 10, for example 4, 5, 6, 7, 8, 9, etc.

[0032] Preferably, in the amine group-containing neutral phosphine extractant of general formula I of the present application, the total number of carbon atoms of R1, R2, R3, R4, R5, R6, R7and R8is 9-68, preferably 12-51, such as 18-44, and the like, including but not limited to 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67and 68.

[0033] Preferably, the amine group-containing neutral phosphine extractant of general formula I is one or more selected from 2-((2-ethylhexyl)amino)-ethylphosphonic acid di(2-ethylhexyl) ester, 1-methyl-2-((2-ethylhexyl)amino)-propylphosphonic acid di(2-ethylhexyl) ester, 2-((2-ethylhexyl)amino)-pentylphosphonic acid di(2-ethylhexyl) ester.

[0034] The amine group-containing neutral phosphine extractant of general formula I can be a commercially available product, or can be synthesized according to the methods known in the prior art (e.g., Xu Yuanyao et al., Synthesis 1990(5): 427-429, etc.).

[0035] For example, the amine group-containing neutral phosphine extractant of general formula I can be synthesized as shown in Reaction Formula 1:

[0036]

[0037] The amine group-containing neutral phosphine extractant of general formula I is obtained by substitution reaction of compound II and compound III,

[0038] wherein R1, R2, R3, R4, R5, R6, R7and R8are the same as defined in general formula I.

[0039] The compound III can be a commercially available product or synthesized according to the known methods in the prior art. For example, the compound III can be synthesized as shown in Reaction Formula 2:

[0040]

[0041] The compound III is obtained by substitution reaction of compound IV and compound V,

[0042] wherein R1, R2, R3, R4, R5and R6are the same as defined in general formula I,

[0043] R9is selected from the group consisting of C1-C 12 alkyl, preferably C4-C 10 alkyl, more preferably C5-C9 alkyl, most preferably C6-C8 alkyl.

[0044] The compound IV can be a commercially available product or synthesized according to known methods in the prior art.

[0045] Alternatively, the amine group-containing neutral phosphine extractant of general formula I can be synthesized as shown in Reaction Scheme 3:

[0046]

[0047] The compound VI is subjected to a substitution reaction with the compound VII to obtain the amine group-containing neutral phosphine extractant of general formula I,

[0048] wherein R1, R2, R3, R4, R5, R6, R7and R8are the same as defined in general formula I,

[0049] The compound VI can be a commercially available product or synthesized according to known methods in the prior art.

[0050] Alternatively, when R4and R6are hydrogen, the amine group-containing neutral phosphine extractant of general formula I can be synthesized as shown in Reaction Scheme 4:

[0051]

[0052] The compound VIII is subjected to an addition reaction with the compound II to obtain the amine group-containing neutral phosphine extractant of general formula I,

[0053] wherein R1, R2, R3, R5, R7and R8are the same as defined in general formula I,

[0054] The compound VIII can be a commercially available product or synthesized according to known methods in the prior art. For example, the compound VIII can be synthesized as shown in Reaction Scheme 5:

[0055]

[0056] The compound IX is subjected to an addition reaction with the compound X to obtain the compound VIII,

[0057] wherein R1, R2, R3and R5are the same as defined in general formula I,

[0058] The compound X can be a commercially available product or synthesized according to known methods in the prior art.

[0059] According to another aspect of the present application, there is provided a method for extracting and separating indium, the method comprising the step of extracting indium from an indium-containing feed solution using the amine group-containing neutral phosphine extractant of general formula I described above to separate indium.

[0060] In one embodiment, the method for extracting and separating indium according to the present application can be carried out by using a solvent extraction method, which comprises: mixing a neutral phosphine extractant system comprising an amine group-containing neutral phosphine extractant of general formula I (hereinafter sometimes referred to as an organic phase) with an indium-containing feed solution to carry out extraction to obtain an indium-containing extract solution.

[0061] After the neutral phosphine extractant contacts with indium in the feed solution, an indium-containing extraction complex is formed, thereby separating indium from the feed solution into the organic phase.

[0062] The neutral phosphine extractant system comprises an amine group-containing neutral phosphine extractant of general formula I, an optional auxiliary extractant, an optional phase modifier, and a diluent. Preferably, the neutral phosphine extractant system consists of the above components.

[0063] The auxiliary extractant mainly plays a role of assisting extraction, and can enhance the extraction performance of the amine group-containing neutral phosphine extractant for indium. The auxiliary extractant can be selected from phosphorus (phosphine) extractants of general formula XI:

[0064]

[0065] wherein,

[0066] Z is O or S;

[0067] R9is selected from the group consisting of hydrogen, C1-C 12 alkyl, C1-C 12 alkoxy, -SH, and -NH2substituted with at least one substituent selected from the group consisting of C1-C 12 alkyl, and the like, preferably selected from the group consisting of hydrogen, C1-C 10 alkyl, C1-C 10 alkoxy, -SH, and -NH2substituted with at least one substituent selected from the group consisting of C4-C 10 alkyl, and the like, more preferably selected from the group consisting of C4-C 10 alkyl and C4-C 10 alkoxy;

[0068] R 10 and R 11 are each independently selected from the group consisting of C4-C 12 alkyl, C4-C 12 alkoxy, and -NH2substituted with at least one substituent selected from the group consisting of C4-C 12 alkyl, and the like, preferably selected from the group consisting of C4-C 10 alkyl, C4-C 10 alkoxy, and -NH2substituted with at least one substituent selected from the group consisting of C4-C 10 alkyl, and the like, more preferably selected from the group consisting of C4-C 10 alkyl and C4-C10 Alkyl group.

[0069] Suitable auxiliary extractants can be selected from: neutral phosphorus (phosphine) extractants such as linear trialkylphosphine oxide (Cyanex 923), branched trialkylphosphine oxide (Cyanex 925), trioctylphosphine oxide (TOPO), dimethylheptyl methylphosphonate (P350), di(-2-ethylhexyl) 2-ethylhexylphosphonate, and tributyl phosphate (TBP); and di(2,4,4-trimethylpentyl)dithiophosphonic acid (Cyanex 301), di(2,4,4-trimethylpentyl)thiophosphonic acid (Cyanex 301), etc. Acidic phosphorus (phosphine) extractants of 302), bis(2-ethylhexyl)phosphonic acid (P204), 2-ethylhexylphosphonic acid mono-2-ethylhexyl ester (P507), bis(2,4,4-trimethylpentyl)phosphonic acid (Cyanex272), and bis(2-ethylhexyl)phosphonic acid (P227 or P229); neutral phosphoramide extractants disclosed in CN201410409451.0 and CN201410040023.5, such as triisooctylphosphamide, diisooctyl-isooctoxyphosphamide, isooctyl-diisooctoxyphosphamide, tri(diisobutyl)phosphamide, di(diisobutyl)-isooctoxyphosphamide, tridecylphosphamide, and dihexyl-decoxyphosphamide; and mixed extractants of the above extractants in any proportion.

[0070] The phase modifier mainly functions to improve the physical phenomena of extraction, and it can be selected from C4 to C6. 10 One or more of alkanols and tributyl phosphate, preferably one or more of n-octanol, isooctol, 2-methylheptanol, and a mixture of the above three alcohols in any proportion and tributyl phosphate; more preferably a mixture of alcohols or 2-methylheptanol.

[0071] The diluent is selected from: C5~C 16 Alkanes, such as pentane, hexane, heptane, octane, nonane, decane, undecane, dodecane, tridecane, tetradecane, pentadecane, hexadecane, etc.; aviation kerosene; sulfonated kerosene; liquid paraffin, such as light lubricating oil fractions at 250–400℃; C5–C6 16 Alicyclic alkanes, such as cyclopentane, C1-C4 alkyl-substituted cyclopentane, cyclohexane, C1-C4 alkyl-substituted cyclohexane, decahydronaphthalene, etc.; C6-C 10 Aromatic hydrocarbons, such as benzene, toluene, xylene (including ortho-, meta-, para-xylene and mixed xylenes), etc. Preferably, the diluent is one or more selected from aviation kerosene, sulfonated kerosene, heptane and xylene.

[0072] In the amine group-containing neutral phosphine extraction system, the volume ratio of the amine group-containing neutral phosphine extractant, the optional auxiliary extractant, the optional phase modifier and the diluent can be: amine group-containing neutral phosphine extractant: auxiliary extractant: phase modifier: diluent = about 1-60: about 0-40: about 0-20: about 40-110, more preferably: amine group-containing neutral phosphine extractant: auxiliary extractant: phase modifier: diluent = about 10-40: about 0-20: about 0-20: about 50-100; and still more preferably: amine group-containing neutral phosphine extractant: auxiliary extractant: phase modifier: diluent = about 15-35: about 0-15: about 0-15: about 55-90, for example: amine group-containing neutral phosphine extractant: auxiliary extractant: phase modifier: diluent = about 15-35: about 3-15: 0: about 55-90, or: amine group-containing neutral phosphine extractant: auxiliary extractant: phase modifier: diluent = about 15-35: 0: about 3-15: about 55-90, or: amine group-containing neutral phosphine extractant: auxiliary extractant: phase modifier: diluent = about 15-35: 0: 0: about 55-90.

[0073] The feed solution is an indium-containing sulfuric acid solution. The indium concentration can be about 0.0001-1 mol / L, for example 0.001, 0.010, 0.020, 0.030, 0.040, 0.050, 0.10, 0.20, 0.30, 0.50 mol / L, etc., but is not limited thereto; and the sulfuric acid concentration of the feed solution is about 0.1-5 mol / L, preferably about 0.15-4 mol / L, for example 0.2, 0.5, 0.8, 1.0, 1.5, 2.0, 2.5, 3.0, 3.5 mol / L, but is not limited thereto.

[0074] In practical applications, the feed solution can also contain alkali metals, alkaline earth metals, associated metal elements zinc, gallium and non-metal elements, etc. In particular, in addition to indium, the feed solution also contains one or more selected from zinc and gallium. In some embodiments, the feed solution is a zinc replacement residue sulfuric acid leaching solution obtained by leaching zinc residue using sulfuric acid. The zinc replacement residue sulfuric acid leaching solution generally contains metal elements such as zinc, indium and gallium. In this case, the method of the present application can selectively extract and separate indium from impurity elements.

[0075] In the extraction step, preferably, the extraction stages can be 1-10 stages, preferably 1-5 stages.

[0076] Preferably, the flow ratio of the neutral phosphine extraction system to the feed solution can be about 0.2-20:1, preferably about 0.5-10:1. The flow ratio changes mainly according to the concentration of indium in the feed solution. When the concentration of indium in the feed solution is high, the flow of the neutral phosphine extraction system is appropriately increased to ensure that the indium can be fully extracted into the organic phase.

[0077] The solvent extraction method according to the present application further comprises a step of washing the indium-containing extract solution with a washing solution (also referred to as washing liquid, washing acid, washing agent). The washing process can further reduce the content of impurity elements in the indium-containing extract solution, thereby helping to improve the purity of the final indium product.

[0078] The washing solution is water or a mixed solution of water mixed with hydrochloric acid, sulfuric acid, nitric acid in any ratio, and the washing solution optionally further contains chloride, such as sodium chloride, potassium chloride, ammonium chloride. The molar concentration of chloride ions in the washing solution is preferably 0-0.5 mol / L. The washing stage can be 0-10 stages, preferably 0-5 stages. The flow ratio of the indium-containing extract solution to the washing solution can be about 1:0.1-5, preferably about 1:0.2-2.

[0079] The method according to the present application further comprises a step of stripping the indium from the indium-containing extract solution with a stripping agent (also referred to as stripping liquid, stripping solution, stripping extract solution) to obtain a indium-containing stripping product. The organic phase after stripping can be recycled and used again to extract and separate indium from the indium-containing feed solution.

[0080] The stripping solution is a hydrochloric acid solution, or an aqueous solution of sodium chloride, potassium chloride, ammonium chloride, or a mixed solution of the aqueous solution of the chloride mixed with hydrochloric acid, sulfuric acid, nitric acid in any ratio, and the molar concentration of chloride ions in the stripping solution is 0-4 mol / L, preferably 1-3 mol / L. The stripping stage can be 1-10 stages, preferably 2-6 stages. The flow ratio of the indium-containing extract solution to the stripping solution can be about 1:0.1-10, preferably 1:0.2-1.

[0081] In the solvent extraction method according to the present application, the extraction, washing and stripping can be carried out using a liquid separation device known in the art, preferably in a series of liquid separation funnels, mixed clear extraction tanks or centrifugal extractors, more preferably in mixed clear extraction tanks or centrifugal extractors.

[0082] In the solvent extraction method according to the present application, the above-mentioned extraction, washing and stripping can be carried out intermittently or continuously, preferably continuously.

[0083] In another embodiment, the method for extracting and separating indium according to the present application is carried out using a solid-liquid extraction method, which comprises using a solid separation material prepared using an amine-containing neutral phosphine extractant of general formula I to separate and purify indium. More specifically, the method comprises contacting the solid separation material prepared using an amine-containing neutral phosphine extractant of general formula I with an indium-containing feed solution to carry out extraction to obtain an indium-containing solid separation material.

[0084] In one embodiment, the solid-liquid extraction method is carried out in a resin column, wherein the solid separation material is added into the resin column, and then the indium-containing solution is added to contact the solid separation material with the indium-containing solution for solid-liquid extraction.

[0085] The content of indium in the indium extraction tail liquid is not particularly limited, but is preferably not more than about 2 g / l, more preferably not more than about 1 g / l.

[0086] The description of the indium-containing solution in the solvent extraction method is also applicable to the solid-liquid extraction method, and thus is not repeated here.

[0087] The solid separation material can be a resin loaded with the neutral phosphine extractant of general formula I, porous silica spheres, diatomite, etc. Preferably, the solid separation material can be prepared by conventional methods in the art, for example, by loading the neutral phosphine extractant of general formula I on a resin, porous silica spheres, diatomite, etc. by impregnation, in-situ polymerization, chemical bonding, etc., preferably by impregnation, in-situ polymerization, etc.

[0088] In one preferred embodiment, the solid separation material is a chelating resin. The method for preparing the chelating resin is not particularly limited, as long as it is loaded with the neutral phosphine extractant of general formula I containing an amine group. For example, resin microparticles can be first prepared by dispersion polymerization, emulsion polymerization, bulk polymerization, suspension polymerization, etc., and then the neutral phosphine extractant of general formula I is loaded on the resin microparticles to obtain the chelating resin, or the neutral phosphine extractant of general formula I is added before or during polymerization to obtain the chelating resin by in-situ polymerization.

[0089] In one embodiment, the chelating resin can be prepared by dispersion polymerization of the neutral phosphine extractant of general formula I with styrene monomers and divinylbenzene monomers. For example, the neutral phosphine extractant of general formula I is mixed with a mixture of styrene monomers and divinylbenzene monomers, an initiator is added in an amount of 2% of the total mass of the oil phase to obtain an oil phase; 10 times the volume of the oil phase of deionized water is taken, 3% gelatin and 0.5% amine thiocyanate are added to the water phase, and mixed to obtain a water phase; the water phase is heated to 50°C, after the gelatin is dissolved, the oil phase is slowly added, and incubated for half an hour, then the temperature is raised to 80°C, and the polymerization reaction is carried out for 5 hours; the temperature is then raised to 90°C for half an hour to solidify the resin, the resin is taken out, washed, sieved, and air-dried to obtain the desired chelating resin. The styrene monomers can be styrene, methylstyrene, ethylstyrene, etc.

[0090] In another embodiment, the solid separation material is porous silica balls, diatomite, etc. loaded with the amine group-containing neutral phosphine extractant of general formula I. There is no particular limitation on the method for loading the amine group-containing neutral phosphine extractant of general formula I on the porous silica balls, diatomite, etc., as long as the amine group-containing neutral phosphine extractant of general formula I can be loaded on the porous silica balls, diatomite, etc. For example, the amine group-containing neutral phosphine extractant of general formula I can be dissolved in a diluent (e.g. dichloromethane, trichloromethane, benzene, toluene, etc. volatile inert solvents), and the porous silica balls, diatomite, etc. separation material is added, and the diluent is slowly evaporated under stirring to obtain the desired solid separation material.

[0091] In one embodiment, the solid-liquid extraction method according to the present application further comprises the step of washing the indium-containing solid separation material with a washing solution. The washing process can further reduce the content of impurity elements in the indium-containing extract solution, thereby helping to improve the purity of the final indium product.

[0092] The description of the washing solution in the solvent extraction method is equally applicable to the solid-liquid extraction method, and thus is not repeated here.

[0093] The washing solution after washing is collected, and when the indium content in the washing solution is less than 0.1 g / l, the addition of the washing solution is stopped.

[0094] In one embodiment, the solid-liquid extraction method according to the present application further comprises the step of stripping the indium in the indium-containing solid separation material with a stripping solution. The stripping solution after stripping is collected, and when the indium content in the stripping solution is less than 0.01 g / l, the addition of the stripping solution can be stopped. The solid separation material after stripping can be recycled and used again to extract and separate indium from the indium-containing feed solution.

[0095] The description of the stripping solution in the solvent extraction method is equally applicable to the solid-liquid extraction method, and thus is not repeated here.

[0096] As an example, the solid-liquid extraction method according to the present application can be operated as follows: the solid separation material is added to a resin column, and then the feed solution is added from the inlet for solid-liquid extraction, and the extract raffinate is collected from the outlet. The indium content in the extract raffinate is periodically analyzed, and when the indium content in the extract raffinate reaches 0.01 g / l, the addition of the feed solution is stopped. Optionally, a washing solution is added for washing, and the washing solution is collected, and when the indium content in the washing solution is less than 0.1 g / l, the addition of the washing solution is stopped. Finally, a stripping solution is added to strip the extracted indium in the solid separation material, and the stripping solution is collected, and when the indium content in the stripping solution is less than 0.01 g / l, the addition of the stripping solution is stopped.

[0097] The term "C1-C6" used in the present application means a group having 1 to 6 carbon atoms. 16Alkyl refers to a straight-chain or branched-chain alkyl group containing 1 to 16 carbon atoms, for example a straight-chain or branched-chain alkyl group having 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 1 1, 12, 13, 14, 15 or 16 carbon atoms, including, without limitation, methyl, ethyl, n-propyl, i-propyl, n-butyl, t-butyl, i-butyl, n-pentyl, neopentyl, i-pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl and the like. C1-C5 alkyl, C1-C6 alkyl, C1-C7 alkyl, C1-C8 alkyl, C1-C9 alkyl, C1-C10 alkyl, C1-C11 alkyl, C1-C12 alkyl, C1-C13 alkyl, C1-C14 alkyl, C1-C15 alkyl and C1-C16 alkyl have the meaning given for alkyl with the indicated number of carbon atoms. 10 Alkyl, C4-C 12 Alkyl, C4-C 10 Alkyl, C5-C9 alkyl and C6-C8 alkyl have the meaning given for alkyl with the indicated number of carbon atoms.

[0098] The term C1-C4 alkyl as used in the present application refers to a straight-chain or branched-chain alkyl group containing 1 to 4 carbon atoms, for example a straight-chain or branched-chain alkyl group having 1, 2, 3 or 4 carbon atoms, including, without limitation, methyl, ethyl, n-propyl, i-propyl, n-butyl, t-butyl, i-butyl and the like. 12 Alkoxy refers to a straight-chain or branched-chain alkoxy group containing 1 to 12 carbon atoms, for example a straight-chain or branched-chain alkoxy group having 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 1 1 or 12 carbon atoms, including, without limitation, methoxy, ethoxy, n-propoxy, i-propoxy, n-butoxy, t-butoxy, i-butoxy, n-pentoxy, neopentoxy, i-pentoxy, hexyloxy, heptyloxy, octyloxy, nonyloxy, decyloxy, undecyloxy, dodecyloxy and the like. C1-C5 alkoxy, C1-C6 alkoxy, C1-C7 alkoxy, C1-C8 alkoxy, C1-C9 alkoxy, C1-C10 alkoxy, C1-C11 alkoxy, C1-C12 alkoxy have the meaning given for alkoxy with the indicated number of carbon atoms. 10 Alkoxy, C4-C 10 Alkoxy, C4-C

[0099] The term C4-C6 alkoxy as used in the present application refers to a straight-chain or branched-chain alkoxy group containing 4 to 6 carbon atoms, for example a straight-chain or branched-chain alkoxy group having 4, 5 or 6 carbon atoms, including, without limitation, n-butoxy, t-butoxy, i-butoxy, n-pentoxy, neopentoxy, i-pentoxy and the like. 10 Alkanol refers to a straight-chain or branched-chain alkanol containing 4 to 10 carbon atoms, for example a straight-chain or branched-chain alkanol having 4, 5, 6, 7, 8, 9 or 10 carbon atoms, including, without limitation, n-butanol, t-butanol, i-butanol, n-pentanol, neopentanol, i-pentanol, hexanol, heptanol, octanol, nonanol, decanol and the like.

[0100] The term C5-C10 alkanol as used in the present application refers to a straight-chain or branched-chain alkanol containing 5 to 10 carbon atoms, for example a straight-chain or branched-chain alkanol having 5, 6, 7, 8, 9 or 10 carbon atoms, including, without limitation, pentanol, hexanol, heptanol, octanol, nonanol, decanol and the like. 16 Alkane refers to a straight-chain or branched-chain alkane containing 5 to 16 carbon atoms, for example a straight-chain or branched-chain alkane having 5, 6, 7, 8, 9, 10, 1 1, 12, 13, 14, 15 or 16 carbon atoms, including, without limitation, pentane, hexane, heptane, octane, nonane, decane, undecane, dodecane, tridecane, tetradecane, pentadecane, hexadecane and the like.

[0101] The term C5-C10 alkane as used in the present application refers to a straight-chain or branched-chain alkane containing 5 to 10 carbon atoms, for example a straight-chain or branched-chain alkane having 5, 6, 7, 8, 9 or 10 carbon atoms, including, without limitation, pentane, hexane, heptane, octane, nonane, decane and the like. 16Alicyclic alkanes refer to saturated cyclic alkanes containing 5 to 16 carbon atoms, which can be monocyclic or bicyclic, such as cyclopentane, cyclohexane, cycloheptane, cyclooctane, cyclononane, cyclodecane, decalin, etc., including substituents, which can be one or more substituents selected from C1-C4 alkyl.

[0102] The term C6-C10 aryl used in the present application refers to aromatic hydrocarbons containing 6 to 10 carbon atoms, such as benzene and benzene substituted with one or more substituents selected from C1-C4 alkyl, such as benzene, toluene, xylene, etc. 10 The term C6-C10 aryl used in the present application refers to aromatic hydrocarbons containing 6 to 10 carbon atoms, such as benzene and benzene substituted with one or more substituents selected from C1-C4 alkyl, such as benzene, toluene, xylene, etc.

[0103] Unless otherwise specified, the numerical ranges set out in the present application include the end point values and all point values in increments or decrements of the minimum unit of the end point values between the end point values and all sub-ranges consisting of these point values.

[0104] Examples

[0105] In order to further illustrate the scheme of the present application, specific examples of the present application are provided to help those skilled in the art to understand and implement the present application, but the present application is not limited to these examples.

[0106] Reagents and sources

[0107] Di(2-ethylhexyl) phosphite, sulfonated kerosene, aviation kerosene and TBP were purchased from Shanghai Liayishi Chemical Co., Ltd. 1,8-diazabicycloundec-7-ene, 1,3-bis(diphenylphosphino)propane, nickel acetate, heptane, acetylene, 1-pentynyl, 2-butynyl and 2-ethylhexylamine were purchased from Aldrich.

[0108] Feed solution, washing solution and stripping agent were self-made in the laboratory.

[0109] Other reagents (such as acids, etc.) were commercially available analytical reagents.

[0110] The purity of the product was determined by ICP-OES (instrument model: Optical-8000, manufacturer: Perkin Elmer).

[0111] Nuclear magnetic resonance instrument was Varian Mercury 300.

[0112] Mass spectrometer was Bruker Daltonics Flex mass spectrum analyzer.

[0113] Infrared was Bruker Vertex 70 spectrometer.

[0114] Preparation example

[0115] Preparation Example 1: Preparation of di(2-ethylhexyl) 2-((2- ethylhexyl)amino)ethylphosphonate

[0116]

[0117] Into a 250 mL three-necked flask equipped with a mechanical stirrer and a condenser reflux apparatus, 93.6 g of di(2-ethylhexyl) phosphite, 231.4 mg of nickel acetate, 767.2 mg of 1,3-bis(diphenylphosphino)propane, 456.4 mg of 1,8-diazabicycloundec-7-ene were added, heated to 100°C, stirred for 15 minutes at this temperature, then acetylene was introduced and the reaction was heated at 120°C for 100 minutes. After the reaction was completed, it was cooled to room temperature, washed with water three times to obtain an intermediate compound. Into a 500 mL three-necked round-bottom flask, 0.2 mol of the above intermediate compound, 0.2 mol of 2-ethylhexylamine, and 200 mL of water were added. The reaction was heated and stirred under reflux for 4 hours. After the reaction was completed, the aqueous phase was separated, and the oil phase was washed with water three times to obtain the target product.

[0118] Yield: 98.5%. 31 P NMR (243 MHz, CDCl3) δ: 30.37 (s); 1 H NMR (600 MHz, CDCl3) δ: 0.89 (t, 18H, CH3), 1.23-1.43 (m, 24H, CH2), 1.50 (m, 2H, CH), 1.69 (m, 1H, CH), 1.87 (t, 2H, CH2), 2.01 (s, 1H, NH), 2.69-2.78 (m, 4H, CH2), 3.94 (m, 4H, CH2); MS-ESI m / z: [M+H] + 462.7; IR (KBr), v / cm -1 : 1208 (P=O), 1050, 993 (P-O-C).

[0119] Preparation Example 2: Preparation of di(2-ethylhexyl) 1-methyl-2-((2- ethylhexyl)amino)propylphosphonate

[0120]

[0121] The target product was prepared by the same process as in Preparation Example 1, except that 2-butyne was used instead of acetylene.

[0122] Yield: 96.7%. 31 P NMR (243 MHz, CDCl3) δ: 30.62; MS-ESI m / z: [M+H] + 490.6; IR (KBr), v / cm-1 :1225 (P=O).

[0123] Preparation Example 3: Preparation of 2-((2-ethylhexyl)amino)-pentylphosphonic acid di(2- ethylhexyl) ester

[0124]

[0125] The target product was prepared by the same process as Preparation Example 1 except that 1-pentyn-3-yl was used instead of ethynyl.

[0126] Yield: 98.2%. 31 P NMR (243 MHz, CDC13) δ: 30.5; MS-ESI m / z: [M+H] + 504.7; IR (KBr), v / cm -1 :1229 (P=O).

[0127] Extraction Example

[0128] The extraction efficiency E% and the distribution ratio D were calculated as follows:

[0129]

[0130]

[0131] wherein [M] (aq,init) and [M] (aq) are the initial concentration and the equilibrium concentration of the metal ion in the aqueous phase, respectively.

[0132] The separation factor β of indium (In) from the impurity metal element (M) was calculated as follows In / M :

[0133]

[0134] wherein D In is the distribution ratio of the indium ion, and D M is the distribution ratio of the impurity metal element ion.

[0135] Extraction Example 1

[0136] The organic phase was prepared: the organic phase consisted of 5% 2-((2-ethylhexyl)amino)-ethylphosphonic acid di(2-ethylhexyl) ester and 95% n-heptane by volume fraction, and the molar concentration of the extractant in the organic phase was 0.1 mol / L.

[0137] The single solution was prepared: the single solutions of indium, gallium and zinc were taken respectively, diluted with distilled water to the required concentration, and adjusted to the appropriate sulfuric acid concentration with concentrated sulfuric acid, and the concentrations of indium, gallium and zinc were all 0.01 mol / L.

[0138] The organic phase was mixed with the single feed liquid at a volume ratio of 1:1, and single-stage extraction was carried out at room temperature. During the extraction process, the phase separation was rapid, reaching equilibrium within 1 minute, and the phase interface was clear, without emulsification or the generation of a third phase.

[0139] After the extraction was completed, the extraction rate E%, the distribution ratio D, and the separation coefficient β of indium (In) and impurity metal elements (M) were calculated In / M .

[0140] The relationship diagram of the extraction rate of metal ions and the concentration of sulfuric acid is shown in Figure 1 .

[0141] Table 1 below summarizes the E%, the distribution ratio D, and the separation coefficient β of indium (In) and impurity metal elements (M) under the condition of partial sulfuric acid concentration In / M .

[0142] Table 1

[0143]

[0144] Comparative Extraction Example 1

[0145] Except that (2-ethylhexyl) aminomethylphosphonic acid di(2-ethylhexyl) ester shown in the following formula was used instead of 2-((2-ethylhexyl) amino)-ethylphosphonic acid di(2-ethylhexyl) ester, experiments were carried out under other experimental conditions in Extraction Example 1. The results are shown in Figure 2 .

[0146]

[0147] Figure 2 The relationship diagram of the extraction rate of (2-ethylhexyl) aminomethylphosphonic acid di(2-ethylhexyl) ester for extracting indium, gallium, and zinc measured in Comparative Extraction Example 1 and the concentration of sulfuric acid is shown. It can be seen from Figure 2 that under the same conditions as Extraction Example 1, (2-ethylhexyl) aminomethylphosphonic acid di(2-ethylhexyl) ester does not extract indium, gallium, and zinc substantially.

[0148] Extraction Example 2

[0149] The organic phase was prepared: the organic phase consisted of 5% 2-((2-ethylhexyl) amino)-ethylphosphonic acid di(2-ethylhexyl) ester and 95% n-heptane by volume fraction, and the molar concentration of the extractant in the organic phase was 0.1 mol / L.

[0150] Preparation of the mixed solution containing indium: single solutions of indium, gallium and zinc were mixed, and distilled water was added to dilute the mixed solution to the desired concentration. Concentrated sulfuric acid was added to adjust the concentration of sulfuric acid to 2.40 mol / L. The concentrations of indium, gallium and zinc in the mixed solution were 0.024 mol / L, 0.020 mol / L and 0.023 mol / L, respectively, and the total concentration was 0.067 mol / L.

[0151] The organic phase was mixed with the mixed solution containing indium at a volume ratio of 1:1, and single-stage extraction was carried out at room temperature. After the extraction was completed, the extraction rate E%, the distribution ratio D and the separation coefficient β of indium (In) and impurity metal elements (M) were calculated In / M (see Table 2). During the extraction process, the phase separation was rapid, reaching equilibrium within 1 minute, and the phase interface was clear without emulsification or the generation of a third phase.

[0152] Table 2

[0153] In Ga Zn E％ 94.17 1.50 0 D 16.14 0.015 0 β In / M ]]> 1 1060 +∞

[0154] Extraction Example 3

[0155] Preparation of the organic phase: the organic phase was composed of 5% 2-((2- ethylhexyl) amino) pentyl phosphonic acid di (2- ethylhexyl) ester and 95% sulfonated kerosene by volume fraction, and the molar concentration of the extractant in the organic phase was 0.1 mol / L.

[0156] Preparation of the mixed solution containing indium: single solutions of indium, gallium and zinc were mixed, and distilled water was added to dilute the mixed solution to the desired concentration. Concentrated sulfuric acid was added to adjust the concentration of sulfuric acid to 1.0 mol / L. The concentrations of indium, gallium and zinc in the mixed solution were 0.04 mol / L, 0.01 mol / L and 0.01 mol / L, respectively, and the total concentration was 0.06 mol / L.

[0157] The organic phase was mixed with the mixed solution containing indium at a volume ratio of 1:1, and single-stage extraction was carried out at room temperature. After the extraction was completed, the extraction rate E%, the distribution ratio D and the separation coefficient β of indium (In) and impurity metal elements (M) were calculated In / M (see Table 3). During the extraction process, the phase separation was rapid, reaching equilibrium within 1 minute, and the phase interface was clear without emulsification or the generation of a third phase.

[0158] Table 3

[0159] In Ga Zn E％ 96.62 0.60 0 D 28.59 0.006 0 β In / M ]]> 1 4765 +∞

[0160] Extraction Example 4

[0161] Preparation of the organic phase: the organic phase was composed of 5% 2-((2- ethylhexyl) amino) pentyl phosphonic acid di (2- ethylhexyl) ester and 95% sulfonated kerosene by volume fraction, and the molar concentration of the extractant in the organic phase was 0.1 mol / L.

[0162] Preparation of the mixed solution containing indium: the single solutions of indium, gallium and zinc were mixed, and then distilled water was added to dilute the solution to the desired concentration. Concentrated sulfuric acid was added to adjust the concentration of sulfuric acid to 1.5 mol / L. The concentrations of indium, gallium and zinc in the mixed solution were 0.03 mol / L, 0.02 mol / L and 0.01 mol / L, respectively, and the total concentration was 0.06 mol / L.

[0163] The organic phase was mixed with the mixed solution containing indium at a volume ratio of 1:1, and single-stage extraction was carried out at room temperature. After the extraction was completed, the extraction rate E%, the distribution ratio D and the separation coefficient β of indium (In) and impurity metal elements (M) were calculated In / M (see Table 4). During the extraction process, the phase separation was rapid, reaching equilibrium within 1 minute, and the phase interface was clear without emulsification or the generation of a third phase.

[0164] Table 4

[0165]

[0166] Example 1

[0167] Preparation of the organic phase: 0.5 L of 2-((2-ethylhexyl)amino)-ethyl phosphonic acid di(2-ethylhexyl) ester was mixed with 9.5 L of n-heptane to prepare the organic phase.

[0168] The feed solution was a 0.025 mol / L indium sulfate solution with a sulfuric acid concentration of 2.5 mol / L.

[0169] The washing solution was pure water.

[0170] The stripping agent was a 2.0 mol / L hydrochloric acid solution.

[0171] The extraction separation experiment was carried out using a 250 ml mixed-settling extraction tank. First, 1-stage countercurrent extraction was carried out with a flow rate ratio of the organic phase to the feed solution of 10 mL / min:5.6 mL / min to obtain an indium-containing extraction solution and an indium extraction tail liquid. Then, 2-stage countercurrent washing was carried out with a flow rate ratio of the indium-containing extraction solution to the washing solution of 10 mL / min:5 mL / min. Next, 4-stage countercurrent stripping was carried out with a flow rate ratio of the indium-containing extraction solution to the stripping agent of 10 mL / min:3.5 mL / min to obtain an indium-containing stripping solution. The obtained stripping solution was precipitated, filtered and washed to obtain indium hydroxide, and the purity of indium was 99%.

[0172] Example 2

[0173] Preparation of the organic phase: 1 L of 2-((2-ethylhexyl)amino)-ethyl phosphonic acid di(2-ethylhexyl) ester, 1 L of TBP and 8 L of aviation kerosene were mixed to prepare the organic phase.

[0174] The feed solution is a 0.05 mol / L indium sulfate solution, and the concentration of sulfuric acid is 1.5 mol / L.

[0175] The stripping agent is a 2.5 mol / L hydrochloric acid solution.

[0176] The extraction experiment is carried out in a 250 ml centrifugal extractor. First, 2-stage countercurrent extraction is carried out, the flow rate ratio of the organic phase to the feed solution is 10 mL / min:5.6 mL / min, and indium-containing extraction solution and indium extraction tail liquid are obtained. Then, 5-stage countercurrent stripping is carried out in a 250 ml mixed-settling extraction tank, the flow rate ratio of the indium-containing extraction solution to the stripping agent is 10 mL / min:3.5 mL / min, and indium-containing stripping solution is obtained. The obtained indium-containing stripping solution is subjected to precipitation, filtration and washing to obtain indium hydroxide, and the purity of indium is 99.9%.

[0177] Example 3

[0178] Preparation of the organic phase: 2L 2-((2-ethylhexyl)amino)-ethyl phosphonic acid di(2-ethylhexyl) ester, 1L TBP, 0.5L 2-methylheptanol and 6.5L sulfonated kerosene are mixed to prepare the organic phase.

[0179] The feed solution is a 0.2 mol / L indium sulfate solution, and the concentration of sulfuric acid is 3.0 mol / L.

[0180] The washing liquid is pure water.

[0181] The stripping agent is a 2.0 mol / L sodium chloride+0.5 mol / L sulfuric acid mixed solution.

[0182] The extraction separation experiment is carried out in a 250 ml centrifugal extractor. First, 5-stage countercurrent extraction is carried out, the flow rate ratio of the organic phase to the feed solution is 10 mL / min:5.6 mL / min, and indium-containing extraction solution and indium extraction tail liquid are obtained. Then, 3-stage countercurrent washing is carried out, the flow rate ratio of the indium-containing extraction solution to the washing liquid is 10 mL / min:10 mL / min. Then, 5-stage countercurrent stripping is carried out, the flow rate ratio of the indium-containing extraction solution to the stripping agent is 10 mL / min:3.5 mL / min, and indium-containing stripping solution is obtained. The obtained indium-containing stripping solution is subjected to precipitation, filtration and washing to obtain indium hydroxide, and the purity of indium is 99.5%.

[0183] Example 4

[0184] Preparation of the organic phase: 3L 1-methyl-2-((2-ethylhexyl)amino)-propyl phosphonic acid di(2-ethylhexyl) ester, 1L 2-methylheptanol and 6L aviation kerosene are mixed to prepare the organic phase.

[0185] The feed solution is a 0.5 mol / L indium sulfate solution, and the concentration of sulfuric acid is 3.0 mol / L.

[0186] The washing liquid is 0.1 mol / L hydrochloric acid solution.

[0187] The stripping agent is a mixed solution of 2.5 mol / L sodium chloride and 0.5 mol / L nitric acid.

[0188] The extraction separation experiment is performed by combining a 250 ml centrifugal extractor with a mixer-settler. First, the 5-stage countercurrent extraction is performed by using the centrifugal extractor, and the flow rate ratio of the organic phase to the feed liquid is 7.5 mL / min: 12.5 mL / min, so as to obtain the indium-containing extraction liquid and the indium extraction tail liquid. Then, the 7-stage countercurrent washing is performed, and the flow rate ratio of the indium-containing extraction liquid to the washing liquid is 7.5 mL / min: 5 mL / min. Next, the 3-stage countercurrent stripping is performed by using the mixer-settler, and the flow rate ratio of the indium-containing extraction liquid to the stripping agent is 7.5 mL / min: 2.5 mL / min, so as to obtain the indium-containing stripping liquid. The obtained stripping liquid is subjected to precipitation, filtration and washing, so as to obtain indium hydroxide, and the purity of indium is 99.5%.

[0189] Example 5

[0190] Preparation of the organic phase: 3L 2-((2-ethylhexyl)amino)-pentyl phosphonic acid di(2-ethylhexyl) ester, 1L TBP and 6L sulfonated kerosene are mixed to prepare the organic phase.

[0191] The feed liquid is 0.3 mol / L indium sulfate solution, and the concentration of sulfuric acid is 3.5 mol / L.

[0192] The washing liquid is 0.1 mol / L sodium chloride + 0.3 mol / L sulfuric acid solution.

[0193] The stripping agent is a mixed solution of 3 mol / L sodium chloride and 1 mol / L sulfuric acid.

[0194] The extraction separation experiment is performed by using a 250 ml centrifugal extractor. First, the 5-stage countercurrent extraction is performed, and the flow rate ratio of the organic phase to the feed liquid is 10 mL / min: 5.6 mL / min, so as to obtain the indium-containing extraction liquid and the indium extraction tail liquid. Then, the 3-stage countercurrent washing is performed, and the flow rate ratio of the indium-containing extraction liquid to the washing liquid is 10 mL / min: 5 mL / min. Next, the 3-stage countercurrent stripping is performed, and the flow rate ratio of the indium-containing extraction liquid to the stripping agent is 10 mL / min: 3.3 mL / min, so as to obtain the indium-containing stripping liquid. The obtained stripping liquid is subjected to precipitation, filtration and washing, so as to obtain indium hydroxide, and the purity of indium is 99.9%.

[0195] Example 6

[0196] (1) Preparation of the extraction and elution resin

[0197] An oil phase was prepared by mixing 50 ml of 2-((2-ethylhexyl)amino)-ethyl phosphonic acid di(2-ethylhexyl) ester with 50 ml of a mixture of styrene-divinylbenzene, wherein the volume ratio of styrene to divinylbenzene was 2:1. 500 ml of deionized water was taken, 15 g of gelatin, 2.5 g of ammonium thiocyanate were added, and heated to 50°C. After the gelatin was completely dissolved, the oil phase was slowly added, stirred for half an hour, and then heated to 80°C. The reaction was carried out for 5 hours, and then heated to 90°C. The resin was taken out, washed with water, and air-dried to obtain 75 g of the XAD resin.

[0198] (2) Extraction experiment

[0199] 50 g of the XAD resin was weighed into a separation column, and an indium-containing solution (0.10 mol / L indium in sulfuric acid solution, sulfuric acid concentration was 1.5 mol / L) was added. The flow rate of the solution was 2 ml / min, and sampling was monitored every 5 minutes. When the content of indium in the tail liquid of indium extraction was greater than 0.01 g / l, the feeding was stopped. The indium-containing XAD resin was washed with a washing solution (pure water) at a flow rate of 2 ml / min. When the concentration of indium in the washing liquid was less than 0.1 g / L, the addition of the washing solution was stopped. The back-extraction solution (2 mol / L hydrochloric acid solution) was added at a flow rate of 2 ml / min. When the concentration of indium in the back-extraction solution was less than 0.01 g / L, the back-extraction was completed, and an indium-containing back-extraction solution was obtained. The obtained indium-containing back-extraction solution was precipitated, filtered, and washed to obtain indium hydroxide. The yield of indium was 95%, and the purity of indium was 99.99%.

[0200] Separation example 1

[0201] Preparation of the organic phase: the organic phase consisted of 5% 2-((2-ethylhexyl)amino)-ethyl phosphonic acid di(2-ethylhexyl) ester and 95% n-heptane by volume fraction.

[0202] Preparation of the indium-containing solution: the concentrations of indium, gallium, and zinc in the indium-containing solution were all 0.02 mol / L, and the concentration of sulfuric acid was 2.5 mol / L.

[0203] The washing solution was pure water.

[0204] The back-extraction agent was a 2.0 mol / L hydrochloric acid solution.

[0205] The extraction separation experiment was carried out by using a 250 ml mixed-settling extraction tank. First, 1-stage countercurrent extraction was carried out, the flow rate ratio of organic phase to feed liquid was 10 mL / min:5.6 mL / min, and indium-containing extraction liquid and indium extraction tail liquid were obtained. Then, 3-stage countercurrent washing was carried out, the flow rate ratio of indium-containing extraction liquid to washing liquid was 10 mL / min:5 mL / min. Then, 3-stage countercurrent stripping was carried out, the flow rate ratio of indium-containing extraction liquid to stripping agent was 10 mL / min:5 mL / min, and indium-containing stripping liquid was obtained. The obtained stripping liquid was subjected to precipitation, filtration and washing to obtain indium hydroxide, the purity of indium was 99%, and the yield was 99%.

[0206] Separation example 2

[0207] Preparation of organic phase: the organic phase was composed of 10% 1-methyl-2-((2-ethylhexyl) amino)-propyl phosphonic acid di(2-ethylhexyl) ester, 10% 2-methyl heptanol and 80% aviation kerosene by volume fraction.

[0208] Preparation of indium-containing feed liquid: the concentrations of indium, gallium and zinc in the indium-containing feed liquid were 0.1 mol / L, 0.05 mol / L and 0.5 mol / L respectively, and the concentration of sulfuric acid was 3.0 mol / L.

[0209] The washing liquid was 0.05 mol / L hydrochloric acid solution.

[0210] The stripping agent was a mixed solution of 2.5 mol / L sodium chloride and 0.5 mol / L nitric acid.

[0211] The extraction separation experiment was carried out by using a 250 ml centrifugal extractor combined with a mixed-settling extraction tank. First, 3-stage countercurrent extraction was carried out by using the centrifugal extractor, the flow rate ratio of organic phase to feed liquid was 7.5 mL / min:12.5 mL / min, and indium-containing extraction liquid and indium extraction tail liquid were obtained. Then, 5-stage countercurrent washing was carried out, the flow rate ratio of indium-containing extraction liquid to washing liquid was 7.5 mL / min:5 mL / min. Then, 3-stage countercurrent stripping was carried out by using the mixed-settling extraction tank, the flow rate ratio of indium-containing extraction liquid to stripping agent was 7.5 mL / min:3.5 mL / min, and indium-containing stripping liquid was obtained. The obtained stripping liquid was subjected to precipitation, filtration and washing to obtain indium hydroxide, the purity of indium was 99.5%, and the yield was 98%.

[0212] Separation example 3

[0213] Preparation of organic phase: the organic phase was composed of 20% 2-((2-ethylhexyl) amino)-pentyl phosphonic acid di(2-ethylhexyl) ester, 15% TBP and 65% sulfonated kerosene by volume fraction.

[0214] The indium-containing feed solution was prepared with 0.5 mol / L indium, 0.1 mol / L gallium, 1.0 mol / L zinc, and 3.5 mol / L sulfuric acid.

[0215] The washing solution was 0.1 mol / L sodium chloride + 0.3 mol / L sulfuric acid.

[0216] The stripping agent was a mixture of 3 mol / L sodium chloride + 1 mol / L sulfuric acid.

[0217] The extraction separation experiment was performed using a 250 ml centrifugal extractor. First, 5-stage countercurrent extraction was performed with a flow rate ratio of organic phase to feed solution of 10 mL / min:5.6 mL / min to obtain an indium-containing extraction solution and an indium extraction tail liquid. Then, 3-stage countercurrent washing was performed with a flow rate ratio of indium-containing extraction solution to washing solution of 10 mL / min:5 mL / min. Next, 3-stage countercurrent stripping was performed with a flow rate ratio of indium-containing extraction solution to stripping agent of 10 mL / min:6.6 mL / min to obtain an indium-containing stripping solution. The obtained stripping solution was subjected to precipitation, filtration, and washing to obtain indium hydroxide, with an indium purity of 99.9% and an indium yield of 98%.

[0218] Separation Example 4

[0219] 50 grams of the extraction resin prepared in (1) of Example 6 were weighed into a separation column, and indium sulfate solid with a purity of 99% was dissolved to prepare a feed solution (0.10 mol / L indium in sulfuric acid solution, with a sulfuric acid concentration of 1.5 mol / L). The feed solution was injected into the separation column at a flow rate of 2 ml / min, and sampling was performed every 5 minutes for monitoring. When the indium content in the indium extraction tail liquid was greater than 0.01 g / L, the feed solution was stopped. The indium-containing extraction resin was washed with a washing solution (pure water) at a flow rate of 2 ml / min. When the indium concentration in the washing solution was less than 0.1 g / L, the washing solution was stopped. A stripping solution (2 mol / L hydrochloric acid solution) was then added at a flow rate of 2 ml / min. When the indium concentration in the stripping solution was less than 0.01 g / L, the stripping was completed, and an indium-containing stripping solution was obtained. The obtained indium-containing stripping solution was subjected to precipitation, filtration, and washing to obtain indium hydroxide, with an indium yield of 95% and an indium purity of 99.99%.

Claims

1. Use of an amine group-containing neutral phosphine extractant of general formula I for the extraction separation of indium: （I） wherein, R1and R2are each independently selected from the group consisting of C1-C 12 alkyl; R3, R4, R5, and R6are each independently selected from C 1-10 alkyl and hydrogen; R7and R8are each independently selected from C 1-16 alkyl and hydrogen.

2. Use according to claim 1, wherein, R1and R2are each independently selected from C4-C 10 alkyl.

3. Use according to claim 1, wherein, R1and R2are each independently selected from C5-C9alkyl.

4. The use according to claim 1, wherein, R1and R2are each independently selected from C6-C8alkyl.

5. The use according to claim 1, wherein, the total number of carbon atoms of R1and R2is an integer between 8 and 20; and / or R1and R2are the same alkyl; and / or R3, R4, R5and R6are selected from C1-C8alkyl and hydrogen; and / or, the total number of carbon atoms of R3, R4, R5and R6is an integer between 0 and 32; and / or R7is selected from C1-C 10 alkyl and hydrogen, R8is selected from C1-C 14 alkyl and hydrogen; and / or the total number of carbon atoms of R7and R8is an integer between 1 and 16; and / or the total number of carbon atoms of R1, R2, R3, R4, R5, R6, R7and R8is 9-68.

6. The use according to claim 5, wherein, the total number of carbon atoms of R1and R2is an integer between 10 and 18; and / or R1and R2are the same C5-C9alkyl; and / or R3, R4, R5and R6are selected from C1-C5alkyl and hydrogen; and / or, the total number of carbon atoms of R3, R4, R5and R6is an integer between 0 and 20; and / or R7is selected from the group consisting of C1-C8alkyl and hydrogen, R8is selected from the group consisting of C1-C 12 alkyl; and / or the total number of carbon atoms of R7and R8is an integer between 2 and 13; and / or the total number of carbon atoms of R1, R2, R3, R4, R5, R6, R7and R8is 12-51.

7. The use according to claim 6, wherein, R3, R4, R5and R6are selected from C1-C3alkyl and hydrogen; and / or, one of R3and R4is H and one of R5and R6is H; and / or the total number of carbon atoms of R7and R8is an integer between 3 and 10; and / or the total number of carbon atoms of R1, R2, R3, R4, R5, R6, R7and R8is 18-44.

8. The use according to claim 1, wherein, the amine group-containing neutral phosphine extractant of general formula I is one or more selected from 2-((2-ethylhexyl)amino)-ethylphosphonic acid bis(2-ethylhexyl) ester, 1-methyl-2-((2-ethylhexyl)amino)-propylphosphonic acid bis(2-ethylhexyl) ester, 2-((2-ethylhexyl)amino)-pentylphosphonic acid bis(2-ethylhexyl) ester.

9. A method for the extraction separation of indium, the method comprising the step of using the amine group-containing neutral phosphine extractant as described in any one of claims 1-8 for the extraction separation of indium from an indium-containing feed solution.

10. The method according to claim 9, wherein, the method for the extraction separation of indium is performed by a solvent extraction method, comprising mixing a neutral phosphine extraction system comprising the amine group-containing neutral phosphine extractant with the indium-containing feed solution to perform the extraction to obtain an indium-containing extract solution; or the method for the extraction separation of indium is performed by a solid-liquid extraction method, comprising contacting a solid separation material prepared using the amine group-containing neutral phosphine extractant with the indium-containing feed solution to perform the extraction to obtain an indium-containing solid separation material.

11. The method of claim 10, wherein, in the solvent extraction method, the neutral phosphine extraction system comprises the amine group-containing neutral phosphine extractant, optionally an auxiliary extractant, optionally a phase modifier, and a diluent.

12. The method according to claim 11, wherein, the auxiliary extractant is selected from phosphorus or phosphine extractants of general formula XI: (XI) wherein, Z is O or S; R9is selected from the group consisting of hydrogen, CrC 12 alkyl, CrC 12 alkoxy, -SH and -NH2 substituted with at least one substituent selected from the group consisting of CrC 12 alkyl; R 10 and R 11 are each independently selected from the group consisting of C4-C 12 alkyl, C4-C 12 alkoxy and -NH2 substituted with at least one substituent selected from the group consisting of C4-C 12 alkyl; The phase modifier is one or more selected from C4-C 10 one or more of an alkanol and tributyl phosphate; The diluent is selected from the group consisting of: C5to C 16 alkanes; aviation kerosene; sulfonated kerosene, liquid paraffin; C5to C 16 cycloalkanes; C6to C 10 aromatics.

13. The method according to claim 12, wherein, R9is selected from the group consisting of hydrogen, CrC 10 alkyl, CrC 10 alkoxy, -SH and -NH2substituted with at least one substituent selected from the group consisting of C4-C 10 alkyl, C4-C R 10 and R 11 each independently is selected from the group consisting of C4-C 10 alkyl, C4-C 10 alkoxy and -NH2 substituted with at least one substituent selected from the group consisting of C4-C 10 alkyl; the phase modifier is one or more selected from the group consisting of n-octanol, iso-octanol, 2-methylheptanol, a mixed alcohol of the three alcohols in any ratio, and tributyl phosphate; said C5-C 16 alkanes are selected from the group consisting of pentane, hexane, heptane, octane, nonane, decane, undecane, dodecane, tridecane, tetradecane, pentadecane, hexadecane; the liquid paraffin is a 250-400℃ light lubricating oil fraction; The C5~C 16 Alicyclic alkanes are selected from cyclopentane, C1-C4 alkyl-substituted cyclopentane, cyclohexane, C1-C4 alkyl-substituted cyclohexane, and decahydronaphthalene; The C6-C 10 Aromatic hydrocarbons are selected from benzene, toluene, and xylene.

14. The method according to claim 13, wherein, R9is selected from C1-C 10 alkyl and C1-C 10 alkoxy; R 10 and R 11 each independently is selected from the group consisting of C4-C 10 alkyl and C4-C 10 alkoxy.

15. The method according to claim 12, wherein, the auxiliary extractant is selected from the group consisting of linear trialkyl phosphine oxide, branched trialkyl phosphine oxide, tri-n-octyl phosphine oxide, dimethylheptyl methylphosphonate, di(-2-ethylhexyl) 2-ethylhexyl phosphonate, tributyl phosphate, bis(2,4,4-trimethylpentyl) dithiophosphonate, bis(2,4,4-trimethylpentyl) thiophosphonate, bis(2-ethylhexyl) phosphoric acid, mono-2-ethylhexyl 2-ethylhexyl phosphonate, bis(2,4,4-trimethylpentyl) phosphonic acid, bis(2-ethylhexyl) phosphonic acid, triisooctyl phosphoramide, diisooctyl-isooctyloxy phosphoramide, isooctyl-diisooctyloxy phosphoramide, tri(diisobutyl) phosphoramide, di(diisobutyl)-isooctyloxy phosphoramide, tridecyl phosphoramide, dihexyl-decyloxy phosphoramide, and a mixed extractant of the above extractants in any ratio; the phase modifier is a mixed alcohol of n-octanol, iso-octanol, and 2-methylheptanol in any ratio or 2-methylheptanol; the diluent is one or more selected from the group consisting of aviation kerosene, sulfonated kerosene, heptane, and xylene.

16. The method of claim 11, wherein, In the amine group-containing neutral phosphine extractive system, the volume ratio of the amine group-containing neutral phosphine extractant, the optional auxiliary extractant, the optional phase modifier, and the diluent is: amine group-containing neutral phosphine extractant: auxiliary extractant: phase modifier: diluent = 1-60: 0-40: 0-20: 40-110.

17. The method of claim 16, wherein, Amine group-containing neutral phosphine extractant: auxiliary extractant: phase modifier: diluent = 10-40: 0-20: 0-20: 50-100.

18. The method of claim 16, wherein, Amine group-containing neutral phosphine extractant: auxiliary extractant: phase modifier: diluent = 15-35: 0-15: 0-15: 55-90.

19. The method of claim 16, wherein, Amine group-containing neutral phosphine extractant: auxiliary extractant: phase modifier: diluent = 15-35: 3-15: 0: 55-90, or amine group-containing neutral phosphine extractant: auxiliary extractant: phase modifier: diluent = 15-35: 0: 3-15: 55-90, or amine group-containing neutral phosphine extractant: auxiliary extractant: phase modifier: diluent = 15-35: 0: 0: 55-90.

20. The method of claim 10, wherein, In the extraction step of the solvent extraction method, the extraction stage number is 1-10 stages; and / or The flow ratio of the neutral phosphine extractive system to the feed liquid is 0.2-20:

1.

21. The method of claim 20, wherein, The extraction stage number is 1-5 stages; and / or The flow ratio of the neutral phosphine extractive system to the feed liquid is 0.5-10:

1.

22. The method of claim 10, wherein, The solvent extraction method further comprises: Optionally washing the indium-containing extract liquid with a washing liquid; Stripping the indium in the indium-containing extract liquid with a stripping agent to obtain an indium-containing stripping product.

23. The method according to claim 22, wherein, The washing stage number is 0-10 stages; and / or The washing flow ratio is 1:0.1-5 of the indium-containing extraction solution to the washing solution; and / or The back-extraction stage number is 1-10 stages; and / or The back-extraction flow ratio is 1:0.1-10 of the indium-containing extraction solution to the back-extraction solution.

24. The method according to claim 22, wherein, The washing stage number is 0-5 stages; and / or The washing flow ratio is 1:0.2-2 of the indium-containing extraction solution to the washing solution; and / or The back-extraction stage number is 2-6 stages; and / or The back-extraction flow ratio is 1:0.2-1 of the indium-containing extraction solution to the back-extraction solution.

25. The method according to claim 22, wherein, In the solvent extraction method, the extraction, washing and back-extraction are carried out in a series of separatory funnels, mixer-settler extraction tanks or centrifugal extractors; and / or In the solvent extraction method, the extraction, washing and back-extraction are carried out intermittently or continuously.

26. The method according to claim 25, wherein, In the solvent extraction method, the extraction, washing and back-extraction are carried out in mixer-settler extraction tanks or centrifugal extractors; and / or In the solvent extraction method, the extraction, washing and back-extraction are carried out continuously.

27. The method of claim 10, wherein, In the solid-liquid extraction method, the solid separation material is selected from resins loaded with amine group-containing neutral phosphine extractants, porous silica spheres, diatomite.

28. The method of claim 10, wherein, In the solid-liquid extraction method, the solid separation material is a LIX resin.

29. The method of claim 10, wherein, The solid-liquid extraction method further comprises: Optionally washing the indium-containing solid separation material with a washing solution; Back-extracting the indium from the indium-containing solid separation material with a back-extraction solution.

30. The method according to claim 22 or 29, wherein, The washing solution is water, or a mixed solution of water mixed with hydrochloric acid, sulfuric acid, nitric acid in any ratio, and the washing solution optionally contains chloride; and / or The back-extraction solution is a hydrochloric acid solution, or a chloride aqueous solution, or a mixed solution of a chloride aqueous solution mixed with hydrochloric acid, sulfuric acid, nitric acid in any ratio; the molar concentration of chloride ions in the back-extraction solution is 0-4 mol / L.

31. The method according to claim 30, wherein, The chloride is selected from sodium chloride, potassium chloride, ammonium chloride; and / or The molar concentration of chloride ions in the washing solution is 0-0.5 mol / L; and / or The molar concentration of chloride ions in the back-extraction solution is 1-3 mol / L.

32. The method of claim 9 or 10, wherein, The indium-containing feed solution is a sulfuric acid solution, wherein the indium concentration is 0.0001-1 mol / L, and the sulfuric acid concentration is 0.1-5 mol / L.

33. The method of claim 32, wherein, The sulfuric acid concentration is 0.15-4 mol / L.

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