Synergistic extraction system and method for microwave-assisted extraction of indium

Abstract

The invention relates to the technical field of indium extraction, in particular to a synergistic extraction system and method for microwave-assisted synergistic extraction of indium. An extraction agent adopted by the synergistic extraction system for extracting the indium with the assistance of the microwaves is Cyanex272 + Versatic 10 acid. According to the novel synergistic extraction system for microwave-assisted indium extraction, efficient selective extraction of indium can be achieved under certain conditions, impurity metals such as zinc and aluminum are almost not co-extracted, and meanwhile the time for achieving extraction balance can be shortened by introducing microwaves. The invention can provide a new method and a new idea for efficient selective extraction of indium.

Description

Technical Field

[0001] The present invention relates to the technical field of indium extraction, and in particular to a microwave-assisted synergistic extraction system and method of indium. Background Art

[0002] Indium is the main raw material for manufacturing electronic and optical devices. Most of indium is used to produce ITO (indium tin oxide), while some is used to produce InP, copper indium gallium selenide thin film (CIGS), etc. Therefore, many countries list indium as a key strategic metal. With the continuous development of electronic technology, the demand for indium is also gradually increasing. Indium is usually recovered from the by-products of zinc, copper and aluminum smelting. In the future, it is very promising to recover indium from discarded LCDs or LEDs and zinc oxide dust.

[0003] Liquid-liquid extraction is a mature process for separating indium from indium-containing solutions. Indium is usually extracted from aqueous solutions using D2EHPA. However, D2EHPA can also extract zinc and aluminum in multi-metal solution systems, resulting in reduced indium purity. In order to overcome the limitations of D2EHPA in indium extraction, some researchers have developed ionic liquids for indium extraction, but ionic liquids are expensive and difficult to recycle, which limits their large-scale production. Synergistic extraction has been widely studied due to its advantages such as good selectivity and high extraction efficiency. Sankum-Nusen et al. used the synergistic extraction system LIX 63+Versatic 10 acid to extract 86% of indium at pH=3.0. Fan et al. studied the synergistic extraction of indium from a mixture of CA100 and N235. The extraction distribution ratio of indium reached its maximum at pH=3.0, and x CA100 =0.8. Ma et al. studied the extraction of gallium, indium and zinc by the synergistic extraction system CA12+N1923 and found that the synergistic extraction system CA12+N1923 has good extraction performance at pH=3.0 and x CA12 =0.2, it has a synergistic effect on the extraction of indium. Hisanori IMURA et al. studied the synergistic extraction of gallium and indium by a mixture of 2,4-pentanedione and 3,5-dichlorophenol, and found that the mechanism of synergistic extraction was caused by outer layer complexation. In recent years, microwaves have been widely used in the fields of pyrometallurgical roasting and hydrometallurgical leaching. Microwave heating is different from the traditional heating method from the outside to the inside. Microwave heating materials cause dielectric loss and human body heat in the electromagnetic field, and have the characteristics of fast heating rate, selectivity and uniform heating. Microwave is an electromagnetic wave that causes polar molecules to vibrate rapidly in a magnetic field, thereby generating energy. Therefore, microwave-assisted extraction of metal ions from aqueous solutions is theoretically feasible. Summary of the invention

[0004] In order to solve the above technical problems, the present invention provides a novel synergistic extraction system for microwave-assisted extraction of indium. The synergistic extraction system can achieve efficient and selective extraction of indium under certain conditions, and almost no co-extraction of impurity metals such as zinc and aluminum. At the same time, the introduction of microwaves can shorten the time to reach extraction equilibrium. The present invention can provide a new method and new idea for efficient and selective extraction of indium.

[0005] In the first aspect, the present invention provides a synergistic extraction system for microwave-assisted extraction of indium, wherein the extractant used is Cyanex272+Versatic 10 acid. The present invention uses a microwave-assisted novel synergistic extraction system Cyanex272+Versatic 10 acid to synergistically extract indium, and the mechanism of synergistic extraction is that the hydrogen ions ionized by Versatic 10 acid combine with -P=O to form OH + -----O=P bond, thereby exerting a synergistic extraction effect. The present invention uses a new synergistic extraction system Cyanex272+Versatic 10 acid to synergistically extract indium, and under certain conditions, it can efficiently and selectively extract indium.

[0006] Preferably, the volume concentration of Cyanex272 in the synergistic extraction system is 15-25%, and the volume concentration of Versatic 10 acid is 5-15%. In the embodiment of the present invention, the synergistic extraction coefficient of the synergistic extraction system Cyanex272+Versatic 10 acid is greater than 1, and has a positive synergistic effect on the extraction of indium, especially at a specific volume concentration, it can exert the best synergistic extraction effect, such as Figure 1 As shown (extraction distribution ratio of D-indium; synergistic extraction coefficient of R-indium).

[0007] The present invention uses a microwave-assisted novel synergistic extraction system Cyanex272+Versatic 10 acid to synergistically extract indium. The optimal concentration of the extractant Cyanex272+Versatic 10 acid is 30% (V / V), wherein: X Cyanex272 =20%,X Versatic 10 acid =10%.

[0008] Preferably, in the synergistic extraction system, the volume concentration of Cyanex272 is 20%, the volume concentration of Versatic 10 acid is 10%, and the diluent used is preferably sulfonated kerosene.

[0009] In a second aspect, the present invention provides a synergistic extraction method for microwave-assisted extraction of indium, which uses the above-mentioned synergistic extraction system for extraction, comprising the following steps: 1) Prepare the aqueous extraction phase and adjust the pH.

[0010] 2) The aqueous extraction phase is mixed with the synergistic extraction system and subjected to microwave-assisted extraction to obtain an indium-loaded organic phase.

[0011] 3) stripping indium from the indium-loaded organic phase.

[0012] Further preferably, in step 1), the pH of the extraction aqueous phase is adjusted to 2-2.5; the present invention uses a novel synergistic extraction system Cyanex272+Versatic 10 acid to synergistically extract indium, and under the condition of controlling the pH of the aqueous phase, indium can be efficiently and selectively extracted, while almost no impurity metals such as zinc and aluminum are extracted.

[0013] Preferably, the pH of the aqueous extraction phase is adjusted to 2.

[0014] In the present invention, the synergistic extraction system Cyanex272+Versatic 10 acid has good selectivity for indium and a large separation coefficient, and hardly extracts zinc and aluminum at a pH of 2.

[0015] Preferably, in step 1), the main metal ions in the extraction water phase include In, Zn and Al.

[0016] Further preferably, in step 1), the preparation of the extraction aqueous phase comprises: leaching indium from zinc oxide fume with sulfuric acid using ultrasound-microwave combination to obtain a leachate, reducing iron powder, ultrasonically enhancing indium precipitation with calcium carbonate, and then drying the precipitated residue and dissolving it with sulfuric acid to obtain the extraction aqueous phase.

[0017] Preferably, in step 2), the volume ratio of the synergistic extraction system to the extraction aqueous phase is 2:1-1:3.

[0018] Further preferably, in step 2), the contact time of the extraction is 1-5 min, and the microwave operation mode is a constant temperature mode or a constant power mode; preferably, the temperature of the constant temperature mode is 35-40° C.; the microwave power of the constant power mode is 50-90 W.

[0019] Preferably, in step 3), microwave-assisted stripping of indium is used, with a contact time of 1-3 min, a temperature of 35-40° C. and / or a microwave power of 50-90 W. Microwave-assisted stripping of indium from an indium-loaded organic phase can also be used to shorten the time it takes for the stripping to reach equilibrium.

[0020] Further preferably, in step 3), hydrochloric acid is used to extract indium from the indium-loaded organic phase, and the concentration of hydrochloric acid is 1.8-2.2 mol / L, preferably 2 mol / L. The present invention uses a microwave-assisted novel synergistic extraction system Cyanex272+Versatic 10acid to synergistically extract indium, and after the extraction is completed, 2 mol / L hydrochloric acid is used to extract indium from the indium-loaded organic phase for better results.

[0021] Preferably, the volume ratio of the indium-loaded organic phase to hydrochloric acid is 1.5:1 to 3:1.

[0022] In the present invention, a microwave-assisted novel synergistic extraction system Cyanex272+Versatic 10 acid is used to synergistically extract indium. After the extraction is completed, the organic phase after hydrochloric acid stripping is washed with oxalic acid and sulfuric acid, and the organic phase can be recycled for multiple times.

[0023] Preferably, the organic phase after hydrochloric acid stripping is washed with oxalic acid having a preferred concentration of 100 g / L and sulfuric acid having a preferred concentration of 100 g / L, and the organic phase is recycled preferably 3 times.

[0024] The beneficial effects of the present invention are at least that: the present invention uses a microwave-assisted novel synergistic extraction system Cyanex272+Versatic 10 acid to synergistically extract indium, which can efficiently and selectively extract indium. The present invention uses microwave-assisted synergistic extraction of indium, and utilizes microwaves to heat from the inside to the outside and continuously and uniformly, which can increase the contact area between the extracted aqueous phase and the organic phase, improve the extraction rate, and shorten the time for the extraction to reach equilibrium. The present invention uses microwave-assisted synergistic extraction of indium, which is simple and convenient to operate, and can achieve industrial-scale and process-based production. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0026] Figure 1 The synergistic extraction distribution ratio diagram (a) and the synergistic extraction coefficient (b) of indium of the synergistic extraction system provided in an embodiment of the present invention.

[0027] Figure 2 A processing flow chart of a novel microwave-assisted synergistic extraction system provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0028] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the drawings of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0029] It should be understood that the following examples are only exemplary illustrations and explanations of the present invention, and should not be construed as limiting the scope of protection of the present invention. All technologies implemented based on the above content of the present invention are included in the scope that the present invention is intended to protect. Unless otherwise specified, the raw materials and reagents used in the following examples are commercially available products, or can be prepared by known methods. If the specific technology or conditions are not specified in the examples, they are all conventional methods or carried out according to the technology or conditions described in the literature of the field, or according to the product instructions. The reagents and instruments used, etc., which do not indicate the manufacturer, are all conventional products that can be purchased through regular channels.

[0030] In an embodiment of the present invention, a novel synergistic extraction method for synergistically extracting indium from an acid solution of indium-rich precipitated slag is provided, comprising the following steps: 1) Ultrasonic-microwave synergistic leaching was used to prepare the leaching solution. The process conditions were 180 g / L sulfuric acid, 200 W ultrasonic power, 200 W microwave power, 8:1 liquid-to-solid ratio, and 30 min leaching time.

[0031] 2) The zinc oxide smoke leaching solution obtained after filtration was subjected to iron powder reduction and ultrasonic enhanced reduction for 20 minutes to make the Fe 3+ Reduction to Fe 2+ , which is convenient for the subsequent precipitation of indium.

[0032] 3) The leaching solution after the iron powder reduction is put into a 500 ml four-necked flask, the four-necked flask is placed in an ultrasonic-microwave chemical reactor, a pH meter and a temperature thermocouple are inserted into the four-necked flask to monitor the pH value and temperature of the solution.

[0033] 4) Turn on the ultrasonic generator, set the ultrasonic power to 200 W, and turn on the microwave reactor at the same time, but do not run the microwave reactor so as to record the solution temperature; slowly add calcium carbonate powder at the same time, and when the pH of the solution reaches 4, immediately turn off the ultrasonic generator, and quickly filter the precipitate, wash the precipitate residue with deionized water for 5 times, and then put the precipitate residue into an oven to dry for 24 hours.

[0034] 5) The dried precipitate residue was ground and then dissolved in sulfuric acid with a sulfuric acid concentration of 100 g / L and a liquid-to-solid ratio of 5:1. The ultrasonic-assisted dissolution was performed for 30 minutes. After the dissolution was completed, the mother liquor (i.e., the extracted aqueous phase in the embodiment) was obtained by vacuum filtration. The ion concentrations of indium, zinc, and aluminum in the mother liquor were determined by inductively coupled plasma optical emission spectrometry (ICP-OES).

[0035] 6) Mix the extractant Cyanex272 and Versatic 10 acid (neose acid), and then dilute with sulfonated kerosene, Cyanex272 + Versatic 10 acid = 30% (V / V), where: X Cyanex272 =20%, X Versatic 10 =1-X Cyanex272 (V / V). Then microwave-assisted extraction was performed according to certain ratio, pH, contact time, temperature and different microwave powers.

[0036] 7) Use 2 mol / L hydrochloric acid to extract indium from the indium-loaded organic phase.

[0037] Example 1 This embodiment provides a synergistic extraction system for microwave-assisted extraction of indium, wherein the concentration of the extractant Cyanex272+Versatic10 acid is 30% (V / V), wherein: Cyanex272 =20%, X Versatic 10 acid =10%, the diluent is sulfonated kerosene.

[0038] This embodiment also provides a synergistic extraction method for microwave-assisted extraction of indium: first, prepare the extraction aqueous phase according to the method of the above embodiment. The main metal ion concentrations in the extraction aqueous phase are In: 0.795g / L, Zn: 6.7g / L, Al: 0.58g / L. Then the extraction aqueous phase and the synergistic extraction system Cyanex272+Versatic 10 acid diluted with kerosene are mixed and placed in a microwave reactor for microwave-assisted extraction. Among them, the pH of the aqueous phase is adjusted to 2.0, the organic phase (extraction system) is 1:1 to the aqueous phase (extraction aqueous phase), the contact time is 5 minutes, the temperature is 35°C, the stirring rate is 500rpm, the microwave operation mode is the constant temperature mode, and the concentration of the extractant Cyanex272+Versatic 10 acid is 30% (V / V), wherein: X Cyanex272 =20%,X Versatic 10 acid =10%, and the diluent is sulfonated kerosene. At this time, the extraction rates of indium, zinc, and aluminum are 99.84%, 0.15%, and 0.34%, respectively. Then, hydrochloric acid is used to microwave-assisted stripping of indium from the organic phase loaded with indium. The hydrochloric acid concentration is 2 mol / L, the organic phase to water ratio is 1.5:1, the microwave power is 90 W, and the contact time is 3 minutes. The stripping rate of indium is 99.81%.

[0039] Example 2 The same method as in Example 1 was used, except that the pH of the aqueous phase was adjusted to 2.0, the ratio of the organic phase to the aqueous phase was 1:2, the contact time was 5 minutes, the temperature was 35°C, the stirring rate was 500 rpm, the microwave operation mode was constant temperature mode, and the concentration of the extractant Cyanex272+Versatic 10 acid was 30% (V / V), wherein: X Cyanex272 =20%, X Versatic 10 acid =10%, and the diluent is sulfonated kerosene. At this time, the extraction rates of indium, zinc, and aluminum are 95.71%, 0.87%, and 0.23%, respectively. Then, hydrochloric acid is used to microwave-assisted stripping of indium from the organic phase loaded with indium. The hydrochloric acid concentration is 2 mol / L, the organic phase to water ratio is 1.5:1, the microwave power is 90 W, and the contact time is 3 minutes. The stripping rate of indium is 99.79%.

[0040] Example 3 The same method as in Example 1 was used, except that the pH of the aqueous phase was adjusted to 2.0, the ratio of the organic phase to the aqueous phase was 1:3, the contact time was 5 minutes, the temperature was 35°C, the stirring rate was 500 rpm, the microwave operation mode was constant temperature mode, and the concentration of the extractant Cyanex272+Versatic 10 acid was 30% (V / V), wherein: X Cyanex272 =20%, X Versatic 10 acid =10%. At this time, the extraction rates of indium, zinc and aluminum were 93.21%, 0.79% and 0.98% respectively. Then, hydrochloric acid was used to microwave-assisted stripping of indium from the organic phase loaded with indium. The hydrochloric acid concentration was 2 mol / L, the organic phase to water ratio was 1.5:1, the microwave power was 90 W, and the contact time was 3 minutes. The stripping rate of indium was 99.76%.

[0041] Example 4 The same method as in Example 1 was used, except that the pH of the aqueous phase was adjusted to 2.0, the ratio of the organic phase to the aqueous phase was 1:3, the contact time was 1 minute, the temperature was 35°C, the stirring rate was 500 rpm, the microwave operation mode was constant temperature mode, and the concentration of the extractant Cyanex272+Versatic 10 acid was 30% (V / V), wherein: X Cyanex272 =20%, X Versatic 10 acid =10%, and the diluent is sulfonated kerosene. At this time, the extraction rates of indium, zinc, and aluminum are 99.94%, 0.06%, and 0.23%, respectively. Then, hydrochloric acid is used to microwave-assisted stripping of indium from the organic phase loaded with indium. The hydrochloric acid concentration is 2 mol / L, the organic phase to water ratio is 1.5:1, the microwave power is 90 W, and the contact time is 3 minutes. The stripping rate of indium is 99.53%.

[0042] Example 5 The same method as in Example 1 was used, except that the pH of the aqueous phase was adjusted to 2.0, the ratio of the organic phase to the aqueous phase was 1:3, the contact time was 1 minute, the temperature was 40°C, the stirring rate was 500 rpm, the microwave operation mode was constant temperature mode, and the concentration of the extractant Cyanex272+Versatic 10 acid was 30% (V / V), wherein: X Cyanex272 =20%, X Versatic 10 acid =10%, and the diluent is sulfonated kerosene. At this time, the extraction rates of indium, zinc, and aluminum are 99.96%, 0.12%, and 0.90%, respectively. Then, hydrochloric acid is used to microwave-assisted stripping of indium from the organic phase loaded with indium. The hydrochloric acid concentration is 2 mol / L, the organic phase to water ratio is 1.5:1, the microwave power is 90 W, and the contact time is 3 minutes. The stripping rate of indium is 99.94%.

[0043] Example 6 The same method as in Example 1 was used, except that the pH of the aqueous phase was adjusted to 2.0, the ratio of the organic phase to the aqueous phase was 1:3, the contact time was 1 minute, the microwave power was 70 W, the stirring rate was 500 rpm, the microwave operation mode was constant power mode, and the concentration of the extractant Cyanex272+Versatic 10 acid was 30% (V / V), wherein: X Cyanex272 =20%, X Versatic 10 acid =10%, and the diluent is sulfonated kerosene. At this time, the extraction rates of indium, zinc, and aluminum are 98.27%, 1.25%, and 1.46%, respectively. Then, hydrochloric acid is used to microwave-assisted stripping of indium from the organic phase loaded with indium. The hydrochloric acid concentration is 2 mol / L, the organic phase to water ratio is 1.5:1, the microwave power is 90 W, and the contact time is 3 minutes. The stripping rate of indium is 99.89%.

[0044] Comparative example (conventional extraction): First, the aqueous phase was prepared according to the above method, the pH of the aqueous phase was adjusted to 2.0, the organic phase to aqueous phase ratio was 1:3, the contact time was 1 minute, the temperature was 40°C, the stirring rate was 500 rpm, mechanical stirring, water bath heating, the concentration of the extractant Cyanex272+Versatic 10 acid was 30% (V / V), where: X Cyanex272 =20%, X Versatic 10 acid=10%. At this time, the extraction rates of indium, zinc and aluminum were 91.58%, 2.51% and 1.47% respectively. It can be seen that under the same conditions, compared with conventional extraction and microwave-assisted extraction, the extraction rate of indium decreased by 8.38 percentage points, the extraction rate of zinc increased by 2.39 percentage points, and the extraction rate of aluminum increased by 1.57 percentage points. Then, hydrochloric acid was used to strip indium from the organic phase loaded with indium, mechanical stirring, water heating, hydrochloric acid concentration of 2 mol / L, organic phase to water ratio of 1.5:1, temperature of 40 ° C, contact time of 3 minutes, and the stripping rate of indium was 92.02%. It can be seen that the stripping rate of indium decreased by 7.92 percentage points compared with microwave-assisted stripping. This shows that microwave-assisted extraction of indium and microwave-assisted stripping of indium have obvious advantages over conventional methods. Microwaves can improve the extraction rate of indium and inhibit the co-extraction of zinc and aluminum impurity elements, and have broad application prospects.

[0045] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A synergistic extraction system for microwave-assisted extraction of indium, characterized in that: The extractant used was Cyanex272+Versatic 10 acid.

2. The synergistic extraction system for microwave-assisted extraction of indium according to claim 1, characterized in that: The volume concentration of Cyanex272 in the synergistic extraction system is 15-25%, and the volume concentration of Versatic 10 acid is 5-15%.

3. The synergistic extraction system for microwave-assisted extraction of indium according to claim 1 or 2, characterized in that: In the synergistic extraction system, the volume concentration of Cyanex272 is 20%, the volume concentration of Versatic 10 acid is 10%, and the diluent used is preferably sulfonated kerosene.

4. A synergistic extraction method for microwave-assisted extraction of indium, characterized in that: The synergistic extraction system according to any one of claims 1 to 3 is used for extraction, comprising the following steps: 1) Prepare the aqueous extraction phase and adjust the pH; 2) mixing the aqueous extraction phase with the synergistic extraction system and performing microwave-assisted extraction to obtain an indium-loaded organic phase; 3) stripping indium from the indium-loaded organic phase.

5. The novel synergistic extraction system for microwave-assisted extraction of indium according to claim 4, characterized in that: In step 1), the pH of the aqueous phase is adjusted to 2-2.5; preferably, the pH of the aqueous phase is adjusted to 2.

6. The novel synergistic extraction system for microwave-assisted extraction of indium according to claim 4 or 5, characterized in that: In step 1), the main metal ions in the extraction water phase include In, Zn and Al; and / or, the preparation of the extraction water phase includes: ultrasonic-microwave combined leaching of indium from zinc oxide smoke with sulfuric acid to obtain a leachate, iron powder reduction, ultrasonic enhanced calcium carbonate precipitation of indium, and then drying the precipitated residue and dissolving it with sulfuric acid to obtain the extraction water phase.

7. The novel synergistic extraction system for microwave-assisted extraction of indium according to any one of claims 4 to 6, characterized in that: In step 2), the volume ratio of the synergistic extraction system to the extraction aqueous phase is 2:1 to 1:

3.

8. The novel synergistic extraction system for microwave-assisted extraction of indium according to any one of claims 4 to 7, characterized in that: In step 2), the contact time of the extraction is 1-5 min, and the microwave operation mode is a constant temperature mode or a constant power mode; preferably, the temperature of the constant temperature mode is 35-40° C.; the microwave power of the constant power mode is 50-90 W.

9. The novel synergistic extraction system for microwave-assisted extraction of indium according to any one of claims 4 to 8, characterized in that: In step 3), microwave-assisted stripping of indium is used with a contact time of 1 to 3 min, a temperature of 35 to 40° C. and / or a microwave power of 50 to 90 W.

10. The novel synergistic extraction system for microwave-assisted extraction of indium according to any one of claims 4 to 9, characterized in that: In step 3), hydrochloric acid is used to strip indium from the indium-loaded organic phase, and the concentration of the hydrochloric acid is 1.8-2.2 mol / L, preferably 2 mol / L; the volume ratio of the indium-loaded organic phase to the hydrochloric acid is 1.5:1-3:1.

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