阅读说明：本技术 一种液晶面板萃取回收铟的方法及装置 (Method and device for extracting and recycling indium from liquid crystal display panel ) 是由 余广炜 黎长江 于 2021-10-27 设计创作，主要内容包括：本发明涉及一种液晶面板萃取回收铟的方法及装置,方法包括S1,将液晶面板进行破碎后进行绝氧热解,得到热解料；S2：将所述热解料放入酸溶液中浸泡,过滤得到浸泡液；S3：对所述浸泡液进行萃取,所述萃取剂为酰胺衍生物D2EHAG,取上层有机相进行反萃,下层为含铟的溶液。本发明还提供一种液晶面板萃取回收铟的装置,采用本发明的液晶面板萃取回收铟的工艺,回收效率高,处理成本低,具有较好的经济效益和环保价值。(The invention relates to a method and a device for extracting and recovering indium from a liquid crystal panel, wherein the method comprises the steps of S1, crushing the liquid crystal panel, and then carrying out anaerobic pyrolysis to obtain a pyrolysis material; s2: soaking the pyrolysis material in an acid solution, and filtering to obtain a soaking solution; s3: and extracting the soaking solution, wherein the extracting agent is an amide derivative D2EHAG, taking an upper layer organic phase for back extraction, and taking a lower layer indium-containing solution. The invention also provides a device for extracting and recovering indium from the liquid crystal panel, and the process for extracting and recovering indium from the liquid crystal panel has the advantages of high recovery efficiency, low treatment cost, and better economic benefit and environmental protection value.)

1. A method for extracting and recovering indium from a liquid crystal panel is characterized by comprising the following steps: comprises the steps of (a) preparing a mixture of a plurality of raw materials,

s1, breaking the liquid crystal panel, and then carrying out anaerobic pyrolysis to decompose the polarizing film of the liquid crystal panel, and exposing the indium covered by the polarizing film to obtain a pyrolysis material;

s2: soaking the pyrolysis material in an acid solution, and filtering to remove glass residues to obtain a soaking solution;

s3: extracting the soaking solution by adopting an extracting agent, wherein the extracting agent is an amide derivative D2 EHAG; and after extraction, taking the upper organic phase for back extraction, wherein the back extractant is hydrochloric acid, and the lower organic phase is an indium-containing solution.

2. The method for extracting and recovering indium from the liquid crystal panel according to claim 1, wherein: after the liquid crystal panel in S1 is crushed, the granularity is less than or equal to 1 cm.

3. The method for extracting and recovering indium from the liquid crystal panel according to claim 1, wherein: the temperature of the anaerobic pyrolysis in S1 is 500-600 ℃, preferably 550-580 ℃.

4. The method for extracting and recovering indium from a liquid crystal panel according to any one of claims 1 to 3, wherein: and S2, soaking the pyrolysis material in a sulfuric acid solution, wherein the concentration of the sulfuric acid solution is 0.5-2 mol/L.

5. The method for extracting and recovering indium from a liquid crystal panel according to any one of claims 1 to 3, wherein: and soaking in S2, and leaching the pyrolysis material in an ultrasonic mode for 60-120 min.

6. The method for extracting and recovering indium from a liquid crystal panel according to any one of claims 1 to 3, wherein: the volume ratio of the extracting agent to the extracting liquid in the S3 is 1: 3-1: 1, the extracting mode is forced stirring, standing and layering are carried out, the upper organic phase is used for back extraction, and the lower sulfuric acid solution is reused in the S2 as an acid solution; preferably, the pH of the solution is adjusted to 3-6 during extraction.

7. The method for extracting and recovering indium from a liquid crystal panel according to any one of claims 1 to 3, wherein: in the back extraction process of S3, the volume ratio of the back extraction agent to the back extraction liquid is 3: 1-1: 1, the back extraction mode is forced stirring, the lower layer is indium-containing solution, and the upper layer organic phase solution is reused as the extraction agent.

8. A device for extracting and recovering indium from a liquid crystal panel, which applies the method for extracting and recovering indium from a liquid crystal panel as claimed in any one of claims 1 to 7, and is characterized in that: the method comprises the following steps:

the device comprises a conveying device 1# (1), a crushing device (2), a conveying device 2# (3), a pyrolysis device (4), a combustion hearth device (5), a cooling device (6), a conveying device 3# (7), a leaching device (8), an acid storage tank (9), a conveying device 4# (10), a conveying device 5# (11), a purifying device (12), a discharging device (13), a solid-liquid separation device (14), a conveying device 6# (15), an extracting device (16), a conveying device 7# (17), a conveying device 8# (18), an extractant storage tank (19), a conveying device 9# (20), a back-extraction device (21), a conveying device 10# (22), a back-extraction storage tank (23), a conveying device 11# (24) and a conveying device 12# (25), wherein an outlet of the conveying device 1# (1) is connected with an inlet of the crushing device (2), the outlet of the crushing device (2) is connected with the inlet of the conveying device 2# (3), the outlet of the conveying device 2# (3) is connected with the inlet of the pyrolysis device (4), the outlet of the pyrolysis device (4) is connected with the inlets of the combustion hearth device (5), the cooling device (6) and the leaching device (8), the outlet of the combustion hearth device (5) is connected with the inlet of the pyrolysis device (4), the outlet of the cooling device (6) is connected with the inlet of the conveying device 3# (7), the outlet of the conveying device 3# (7) is connected with the inlet of the leaching device (8), the outlet of the acid storage tank (9) is connected with the inlet of the conveying device 4# (10), the outlet of the conveying device 4# (10) is connected with the inlet of the leaching device (8), and the outlet of the leaching device (8) is connected with the inlets of the conveying device 5# (11) and the solid-liquid separation device (14), the outlet of the conveying device 5# (11) is connected with the inlet of the purifying device (12), the outlet of the purifying device (12) is connected with the inlet of the discharging device (13), the outlet of the solid-liquid separation device (14) is connected with the inlets of the conveying device 6# (15) and the extracting device (16), the outlet of the extracting device (16) is connected with the inlets of the conveying device 7# (17) and the conveying device 9# (20), the outlet of the conveying device 7# (17) is connected with the inlet of the acid storage tank (9), the outlet of the conveying device 9# (20) is connected with the inlet of the back-extraction device (21), the outlet of the back-extraction storage tank (23) is connected with the inlet of the conveying device 10# (22), the outlet of the conveying device 10# (22) is connected with the inlet of the back-extraction device (21), and the outlet of the back-extraction device (21) is connected with the inlets of the conveying device 11# (24) and the conveying device 12# (25), the outlet of the conveying device 11# (24) is connected with the inlet of the extractant storage tank (19), the outlet of the extractant storage tank (19) is connected with the inlet of the conveying device 8# (18), and the outlet of the conveying device 8# (18) is connected with the inlet of the extraction device (16).

9. The device for extracting and recovering indium from the liquid crystal panel according to claim 8, wherein: the conveying device 1# (1) is a forklift;

the crushing device (2) is a shear type crusher;

the conveying device 2# (3), the conveying device 3# (7) and the conveying device 6# (15) are screw conveyors, belt conveyors, inclined chutes or scraper conveyors;

the pyrolysis device (4) is an indirect heating type roller pyrolysis furnace;

the combustion hearth device (5) is a conventional coal gas and natural gas combustion hearth;

the cooling device (6) is an indirect roller cooling device;

the leaching device (8), the extracting device (16) and the back-extracting device (21) are stainless steel tanks with electromagnetic stirring or ultrasonic stirring, and are lined with polytetrafluoroethylene.

10. The device for extracting and recovering indium from the liquid crystal panel according to claim 8, wherein: the acid storage tank (9), the extractant storage tank (19) and the back extraction storage tank (23) are stainless steel tanks, and are lined with polytetrafluoroethylene;

the conveying device 4# (10), the conveying device 7# (17), the conveying device 8# (18), the conveying device 9# (20), the conveying device 10# (22), the conveying device 11# (24) and the conveying device 12# (25) are acid and alkali resistant liquid pumps;

the conveying device 5# (11) is a high-temperature flue gas fan;

the purification device (12) is a common wet method or dry method flue gas purification device;

the discharge device (13) is a concrete or steel chimney;

the solid-liquid separation device (14) is a vacuum belt type suction filter, a belt type filter press or a plate and frame type filter press.

Technical Field

The invention relates to the field of harmless treatment of electronic wastes, in particular to a method and a device for extracting and recycling indium from a liquid crystal display panel.

Background

With the improvement of living standard, the demand of intelligent technology is getting bigger and bigger, and products such as liquid crystal televisions, computer monitors, mobile phones, projectors, navigators and the like all adopt liquid crystal display elements. The service life of the liquid crystal display element is generally 5-8 years, and the liquid crystal display element becomes a main object of electronic waste treatment in China. The waste liquid crystal panel has high indium content, indium toxicity is larger than that of lead, the toxicity is not visible, and the waste liquid crystal panel can seriously threaten the environment and human health. On the other hand, because the indium raw material is in short supply and expensive at present, the research on recycling indium in the harmless treatment of the liquid crystal panel has important significance on reasonably utilizing resources and protecting resources.

Patent application CN101722169A discloses that the glass panel containing liquid crystal is broken and then heated and decomposed under nitrogen condition, and the decomposed gas is discharged after high temperature combustion treatment, and the method only relates to the harmless treatment of the liquid crystal panel, and does not relate to the precious metal recovery process.

Patent application CN101133172A provides a method and apparatus for recovering indium from waste liquid crystal display, which utilizes acid to directly dissolve indium in liquid crystal panel, generates indium-containing solution, utilizes zinc or aluminum particles (0.1-8mm) to perform replacement, then utilizes ultrasonic oscillation and other modes to strip indium from metal surface, finally recovers indium after removing other metal impurities by adding alkali, the whole process is complex and is not easy to control.

In view of the limitation of the current liquid crystal panel treatment, the development of an advanced liquid crystal panel harmless treatment process and system has important significance for resource recycling, people health and ecological safety guarantee and the like.

Disclosure of Invention

The invention aims to overcome the defects in the existing liquid crystal panel indium recovery, and provides a method and a device for extracting and recovering indium by using a liquid crystal panel.

The inventor researches the harmless treatment of the liquid crystal panel in the prior art, and the adopted method is referred to CN104498721A, wherein the method adopts an acetone soaking mode to operate the back locking, the time is long, and the extraction and back extraction effects are limited. After repeated investigations, the inventors found that the polarizing film in the liquid crystal panel can be separated from the glass panel by heat treatment under specific conditions, and that the indium adhered to the glass panel is exposed, and that acid leaching can be rapidly achieved.

In another aspect, the invention uses an extraction agent which is an amide derivative D2EHAG, and the preparation method comprises the following steps: step A: preparation of extractant precursors

(A1) Mixing dichloromethane, triethylamine and diisooctylamine, and uniformly stirring at 0-5 ℃ to obtain a diisooctylamine solution;

(A2) adding chloroacetyl chloride into the diisooctylamine solution obtained in the previous step, and stirring and reacting for 3-7h at the temperature of 0-5 ℃;

(A3) after the reaction is finished, adding an acid solution to remove triethylamine, then washing an organic matter with deionized water until a supernatant is neutral, removing water with a drying agent, performing vacuum filtration on the obtained solution to remove the drying agent, then performing rotary evaporation to remove dichloromethane, and performing vacuum drying to obtain an extractant precursor;

and B: preparation of the extractant

(B1) Mixing sodium hydroxide, methanol and glycine, and uniformly stirring to obtain a glycine solution;

(B2) adding the extractant precursor prepared in the step A into the glycine solution obtained in the previous step, and stirring and reacting at 50-70 ℃ for 25-30 h;

(B3) and after the reaction is finished, performing rotary evaporation to remove the methanol, adding dichloromethane, uniformly stirring, adding an acid solution to remove glycine and sodium hydroxide, and then washing the organic matters with deionized water until the supernatant is neutral and does not contain sulfate ions. And (3) dehydrating by using a drying agent, carrying out vacuum filtration on the obtained solution to remove the drying agent, then carrying out rotary evaporation to remove dichloromethane, and carrying out vacuum drying to obtain the extracting agent.

Based on the above, the invention provides a method for extracting and recovering indium from a liquid crystal panel, which mainly comprises anaerobic pyrolysis, extraction and back extraction. In the existing liquid crystal panel recycling technology, an organic solvent such as acetone is usually adopted to soak a liquid crystal panel, so that hazardous waste liquid crystals in the liquid crystal panel are leached by the acetone, and then harmless treatment is carried out by a distillation method, and the steps are complex and the cost is high. However, repeated experiments by the inventor find that organic wastes such as a polarizing film and liquid crystal on the surface of the liquid crystal display screen are thoroughly separated from the display screen under the condition of anaerobic pyrolysis, and are converted into combustible gas in a pyrolysis mode for pyrolysis of the liquid crystal panel, so that harmless treatment of the liquid crystal panel is quickly realized; and then under an acidic condition, enabling indium to efficiently enter the solution to obtain an indium-enriched soaking solution, and utilizing an extracting agent and a solution containing indium obtained under a back extraction condition to directly serve as a chemical raw material, or obtaining indium after zinc sheet or aluminum sheet replacement treatment, thereby realizing resource recovery.

The specific scheme is as follows:

a method for extracting and recovering indium from a liquid crystal panel comprises the following steps,

s1, breaking the liquid crystal panel, and then carrying out anaerobic pyrolysis to decompose the polarizing film of the liquid crystal panel, and exposing the indium covered by the polarizing film to obtain a pyrolysis material;

s2: soaking the pyrolysis material in an acid solution, and filtering to remove glass residues to obtain a soaking solution;

s3: extracting the soaking solution by adopting an extracting agent, wherein the extracting agent is an amide derivative D2 EHAG; and after extraction, taking the upper organic phase for back extraction, wherein the back extractant is hydrochloric acid, and the lower organic phase is an indium-containing solution.

Furthermore, after the liquid crystal panel in S1 is crushed, the granularity is less than or equal to 1 cm.

Further, the temperature of the anaerobic pyrolysis in S1 is 500-600 ℃, preferably 550-580 ℃.

Further, the pyrolysis material is soaked in a sulfuric acid solution in S2, wherein the concentration of the sulfuric acid solution is 0.5-2 mol/L.

Further, soaking in S2, and leaching the pyrolysis material in an ultrasonic manner for 60-120 min.

Further, the volume ratio of the extracting agent to the extraction liquid in the S3 is 1: 3-1: 1, the extraction mode is forced stirring, standing and layering are carried out, the upper organic phase is used for back extraction, and the lower sulfuric acid solution is reused in the S2 as an acid solution; preferably, the pH of the solution is adjusted to 3-6 during extraction.

Further, in the back extraction process in S3, the volume ratio of the back extraction agent to the back extraction liquid is 3: 1-1: 1, the back extraction mode is forced stirring, the lower layer is an indium-containing solution, and the upper layer organic phase solution is reused as the extraction agent.

The invention also provides a device for extracting and recovering indium from the liquid crystal panel, which comprises the following components:

the device comprises a conveying device 1# (1), a crushing device (2), a conveying device 2# (3), a pyrolysis device (4), a combustion hearth device (5), a cooling device (6), a conveying device 3# (7), a leaching device (8), an acid storage tank (9), a conveying device 4# (10), a conveying device 5# (11), a purifying device (12), a discharging device (13), a solid-liquid separation device (14), a conveying device 6# (15), an extracting device (16), a conveying device 7# (17), a conveying device 8# (18), an extractant storage tank (19), a conveying device 9# (20), a back-extraction device (21), a conveying device 10# (22), a back-extraction storage tank (23), a conveying device 11# (24) and a conveying device 12# (25), wherein an outlet of the conveying device 1# (1) is connected with an inlet of the crushing device (2), the outlet of the crushing device (2) is connected with the inlet of the conveying device 2# (3), the outlet of the conveying device 2# (3) is connected with the inlet of the pyrolysis device (4), the outlet of the pyrolysis device (4) is connected with the inlets of the combustion hearth device (5), the cooling device (6) and the leaching device (8), the outlet of the combustion hearth device (5) is connected with the inlet of the pyrolysis device (4), the outlet of the cooling device (6) is connected with the inlet of the conveying device 3# (7), the outlet of the conveying device 3# (7) is connected with the inlet of the leaching device (8), the outlet of the acid storage tank (9) is connected with the inlet of the conveying device 4# (10), the outlet of the conveying device 4# (10) is connected with the inlet of the leaching device (8), and the outlet of the leaching device (8) is connected with the inlets of the conveying device 5# (11) and the solid-liquid separation device (14), the outlet of the conveying device 5# (11) is connected with the inlet of the purifying device (12), the outlet of the purifying device (12) is connected with the inlet of the discharging device (13), the outlet of the solid-liquid separation device (14) is connected with the inlets of the conveying device 6# (15) and the extracting device (16), the outlet of the extracting device (16) is connected with the inlets of the conveying device 7# (17) and the conveying device 9# (20), the outlet of the conveying device 7# (17) is connected with the inlet of the acid storage tank (9), the outlet of the conveying device 9# (20) is connected with the inlet of the back-extraction device (21), the outlet of the back-extraction storage tank (23) is connected with the inlet of the conveying device 10# (22), the outlet of the conveying device 10# (22) is connected with the inlet of the back-extraction device (21), and the outlet of the back-extraction device (21) is connected with the inlets of the conveying device 11# (24) and the conveying device 12# (25), the outlet of the conveying device 11# (24) is connected with the inlet of the extractant storage tank (19), the outlet of the extractant storage tank (19) is connected with the inlet of the conveying device 8# (18), and the outlet of the conveying device 8# (18) is connected with the inlet of the extraction device (16).

Further, the conveying device 1# (1) is a forklift;

the crushing device (2) is a shear type crusher;

the conveying device 2# (3), the conveying device 3# (7) and the conveying device 6# (15) are screw conveyors, belt conveyors, inclined chutes or scraper conveyors;

the pyrolysis device (4) is an indirect heating type roller pyrolysis furnace;

the combustion hearth device (5) is a conventional coal gas and natural gas combustion hearth;

the cooling device (6) is an indirect roller cooling device;

the leaching device (8), the extracting device (16) and the back-extracting device (21) are stainless steel tanks with electromagnetic stirring or ultrasonic stirring, and are lined with polytetrafluoroethylene.

Further, the acid storage tank (9), the extractant storage tank (19) and the back extraction storage tank (23) are stainless steel tanks, and are lined with polytetrafluoroethylene;

the conveying device 4# (10), the conveying device 7# (17), the conveying device 8# (18), the conveying device 9# (20), the conveying device 10# (22), the conveying device 11# (24) and the conveying device 12# (25) are acid and alkali resistant liquid pumps;

the conveying device 5# (11) is a high-temperature flue gas fan;

the purification device (12) is a common wet method or dry method flue gas purification device;

the discharge device (13) is a concrete or steel chimney;

the solid-liquid separation device (14) is a vacuum belt type suction filter, a belt type filter press or a plate and frame type filter press.

Has the advantages that:

(1) the method achieves the aim of recycling the metal indium while realizing the quick pyrolysis harmless treatment of the liquid crystal and the polarizing film in the liquid crystal panel, and has environmental protection significance and economic value;

(2) the process flow for recovering indium is simple, the operation is simple, the automation degree is high, the cost is low, and the economic benefit is good;

(3) the invention has clean and tidy treatment process, does not generate secondary pollution, provides a new scheme for realizing complete resource utilization of the liquid crystal panel and has obvious environmental benefit.

In a word, the invention develops the technology for recovering indium by pyrolysis coupling extraction of the liquid crystal panel, has high recovery efficiency, obtains pure solution containing indium, and can greatly improve the prior indium recovery technology.

Drawings

In order to illustrate the technical solution of the present invention more clearly, the drawings will be briefly described below, and it is apparent that the drawings in the following description relate only to some embodiments of the present invention and are not intended to limit the present invention.

Fig. 1 is a schematic structural diagram of an apparatus for extracting and recovering indium from a liquid crystal panel according to an embodiment of the present invention.

Detailed Description

The definitions of some of the terms used in the present invention are given below, and other non-mentioned terms have definitions and meanings known in the art:

a liquid crystal panel: mainly comprises a polarizing film, a glass substrate and liquid crystal, wherein indium exists on the surface of the glass substrate in an ITO form.

In the method for extracting and recovering indium from the liquid crystal panel, the S1 is subjected to anaerobic pyrolysis, the anaerobic pyrolysis condition is to completely pyrolyze the polarizing film and the liquid crystal, and the pyrolysis temperature is 500-600 ℃, preferably 550-580 ℃, and more preferably 570-579 ℃. Indium in the liquid crystal panel covered with the polarizing film is exposed by anaerobic pyrolysis, so that the indium can be efficiently leached in the next acid solution soaking step.

The acid solution in S2 can be sulfuric acid, hydrochloric acid, or nitric acid solution. Preferably, a sulfuric acid solution with the concentration of 0.5-2 mol/L is adopted, so that the indium leaching rate is high.

And (3) performing extraction and back extraction in S3, wherein an extractant is D2EHAG and can be prepared by adopting the method provided by the invention, a key step in the process of preparing the extractant is to prepare an extractant precursor, and a key control condition is ice water bath. The stripping agent is hydrochloric acid, and preferably, the concentration of the stripping hydrochloric acid is 4 mol/L.

Wherein the volume ratio of the extracting agent to the extraction liquid is 1: 3-1: 1, preferably 1:2.5-1:1.5, and the upper organic phase solution is used for back extraction; the back extractant is hydrochloric acid, the volume ratio of the back extractant to the back extraction liquid is 3: 1-1: 1, and preferably 2.5: 1-1.5:1, and the lower layer liquid is pure solution containing indium.

Preferred embodiments of the present invention will be described in more detail below. While the following describes preferred embodiments of the present invention, it should be understood that the present invention may be embodied in various forms and should not be limited by the embodiments set forth herein. The examples do not specify particular techniques or conditions, and are performed according to the techniques or conditions described in the literature in the art or according to the product specifications. The reagents or instruments used are not indicated by the manufacturer, and are all conventional products commercially available. In the following examples, "%" means weight percent, unless otherwise specified.

Example 1

The extractant (D2EHAG) was prepared, preferably by the following steps:

a: preparation of extractant precursors

(1) To a 250mL round bottom flask were added 50mL of dichloromethane and 10.10g of triethylamine (0.1mol), and stirred in an ice water bath (5 ℃ C.) for 1 min; adding 24.20g of diisooctylamine (0.1mol) into the solution, and stirring for 5min in an ice water bath (5 ℃);

(2) weighing 13.66g of chloroacetyl chloride (0.12mol) in a 50mL beaker, transferring to a constant pressure funnel, adding dropwise (about 14 s/drop) to the diisooctylamine solution, and continuously stirring in an ice-water bath (stirring for 5 h);

(3) washing the reaction product on the wall of the flask with 35mL of dichloromethane, stirring for 45min again, transferring to a 250mL separating funnel, adding 15mL of hydrochloric acid solution (0.01mol/L), removing triethylamine, and measuring the acidity of the supernatant with pH test paper;

(4) washing the organic matter with deionized water until the supernatant is neutral (100 mL of water is added for the first 3 times, 150mL of water is added for the second 2 times, and 200mL of water is added for the last 2 times), and adding a proper amount of dichloromethane dropwise if emulsification occurs;

(5) drying with 32.59g anhydrous sodium sulfate for 30min, and vacuum filtering; rotary evaporation to remove dichloromethane (-0.06MPa, 30 ℃); vacuum drying for 48h to constant weight (-0.08MPa, 75 deg.C) to obtain extractant precursor.

B: preparation of extractant (D2EHAG)

(1) 3.19g of granular sodium hydroxide (0.08mol), 60mL of methanol and 6.05g of glycine (0.08mol) are added into a 250mL round-bottom flask and stirred uniformly in a water bath at 60 ℃ to obtain a glycine solution;

(2) using a constant-pressure funnel, dropwise adding 21.04g of extractant precursor (0.066mol) into a glycine solution (completely adding the precursor in a sharp-bottomed flask into the funnel by using 15mL of methanol), after 30min, finishing dropwise adding, and continuously stirring in a water bath at 60 ℃ for 27 h;

(3) after stirring, removing methanol (-0.06MPa, 65 ℃) by rotary evaporation, adding 50mL of dichloromethane into the flask, stirring uniformly, immediately adding 1mol/L sulfuric acid solution (20mL), and removing redundant glycine and sodium hydroxide (the supernatant is acidic);

(4) the reaction was transferred to a separatory funnel and the residue was poured into the funnel with the appropriate amount of dichloromethane (10 mL); washing the organic matter with deionized water, removing impurities until the supernatant is neutral (adding 200mL of water each time, totaling 6 times), and adding a proper amount of dichloromethane (32.5mL) during emulsification; drying with 50.09g anhydrous sodium sulfate for 60min, and vacuum filtering to remove anhydrous sodium sulfate;

(5) the product is subjected to rotary evaporation to remove dichloromethane (-0.06MPa, 40 ℃); vacuum drying for 48h to constant weight (-0.08MPa, 75 deg.C) to obtain the extractant.

The detection proves that the extractant is D2EHAG and the molecular formula is C₂₀H₄₀N₂O₃。

Example 2

The extraction agent prepared in example 1 is used for extracting and recovering indium of the liquid crystal panel, and the method comprises the following steps:

s1: crushing the liquid crystal panel, wherein the granularity is less than 1 cm; placing the broken liquid crystal panel in a pyrolysis furnace for anaerobic pyrolysis to realize complete decomposition of the liquid crystal screen and the polarizing film;

s2: soaking the crushed liquid crystal panel obtained after pyrolysis in a sulfuric acid solution, filtering to obtain a sulfuric acid solution soaking solution, and recovering the soaked glass residues for subsequent resource utilization; the concentration of the sulfuric acid solution is 0.5-2 mol/L.

S3: and (3) carrying out extraction and back extraction treatment on the sulfuric acid solution soaking solution, and recovering to obtain a pure solution containing indium.

The method specifically comprises the following steps:

1) adding an organic extractant into the sulfuric acid soaking solution for extraction, wherein the extraction mode is ultrasonic wave + forced stirring, standing and layering; the upper organic phase solution is used for back extraction;

2) adding a back extraction agent into the extracted organic phase solution for back extraction, wherein the back extraction mode is forced stirring, and standing for layering; the lower layer liquid is pure solution containing indium.

Wherein, in the step 1), the lower sulfuric acid solution is recycled; in the step 2), the upper layer organic phase solution is recycled.

Wherein the volume ratio of the extracting agent to the extraction liquid is 1: 3-1: 1; the back extractant is hydrochloric acid, and the volume ratio of the back extractant to the back extraction liquid is 3: 1-1: 1.

Example 3

An apparatus for extracting and recovering indium from a liquid crystal panel, referring to fig. 1, comprises: the device comprises a conveying device 1# (1), a crushing device (2), a conveying device 2# (3), a pyrolysis device (4), a combustion hearth device (5), a cooling device (6), a conveying device 3# (7), a leaching device (8), an acid storage tank (9), a conveying device 4# (10), a conveying device 5# (11), a purifying device (12), a discharging device (13), a solid-liquid separation device (14), a conveying device 6# (15), an extracting device (16), a conveying device 7# (17), a conveying device 8# (18), an extractant storage tank (19), a conveying device 9# (20), a back-extraction device (21), a conveying device 10# (22), a back-extraction storage tank (23), a conveying device 11# (24) and a conveying device 12# (25).

Wherein, the connection sequence of the equipment is as follows:

the outlet of the conveying device 1# (1) is connected with the inlet of the crushing device (2), the outlet of the crushing device (2) is connected with the inlet of the conveying device 2# (3), the outlet of the conveying device 2# (3) is connected with the inlet of the pyrolysis device (4), the outlet of the pyrolysis device (4) is connected with the inlets of the combustion hearth device (5), the cooling device (6) and the leaching device (8), the outlet of the combustion hearth device (5) is connected with the inlet of the pyrolysis device (4), the outlet of the cooling device (6) is connected with the inlet of the conveying device 3# (7), the outlet of the conveying device 3# (7) is connected with the inlet of the leaching device (8), the outlet of the acid storage tank (9) is connected with the inlet of the conveying device 4# (10), and the outlet of the conveying device 4# (10) is connected with the inlet of the leaching device (8), the outlet of the leaching device (8) is connected with the inlets of the conveying device 5# (11) and the solid-liquid separation device (14), the outlet of the conveying device 5# (11) is connected with the inlet of the purification device (12), the outlet of the purification device (12) is connected with the inlet of the discharge device (13), the outlet of the solid-liquid separation device (14) is connected with the inlets of the conveying device 6# (15) and the extraction device (16), the outlet of the extraction device (16) is connected with the inlets of the conveying device 7# (17) and the conveying device 9# (20), the outlet of the conveying device 7# (17) is connected with the inlet of the acid storage tank (9), the outlet of the conveying device 9# (20) is connected with the inlet of the back-extraction device (21), the outlet of the back-extraction storage tank (23) is connected with the inlet of the conveying device 10# (22), and the outlet of the conveying device 10# (22) is connected with the inlet of the back-extraction device (21), the outlet of the back extraction device (21) is connected with the inlets of the conveying device 11# (24) and the conveying device 12# (25), the outlet of the conveying device 11# (24) is connected with the inlet of the extractant storage tank (19), the outlet of the extractant storage tank (19) is connected with the inlet of the conveying device 8# (18), and the outlet of the conveying device 8# (18) is connected with the inlet of the extraction device (16).

The detailed process described in connection with the apparatus is as follows:

the liquid crystal panel raw material enters a crushing device (2) from a conveying device 1# (1), after the liquid crystal panel raw material is crushed to the granularity of less than 1cm, the liquid crystal panel raw material enters a pyrolysis device (4) from a conveying device 2# (3), and the crushed liquid crystal panel raw material is placed in the pyrolysis device (4) for anaerobic pyrolysis, so that the liquid crystal and the polarizing film are completely decomposed. And cooling the crushed liquid crystal panel obtained after pyrolysis to room temperature by a cooling device (6), and then feeding the crushed liquid crystal panel into a leaching device (8) through a conveying device 3# (7).

Sulfuric acid in the acid storage tank (9) is conveyed to the leaching device (8) through the conveying device 4# (10) to be soaked with the crushed liquid crystal panel obtained after pyrolysis. After the soaking is completed, a solid-liquid separation device (14) is used for separation, and the separated solid phase is subjected to glass residue recovery through a conveying device No. 6 (15) for subsequent resource utilization; the liquid phase component, namely sulfuric acid solution soak solution enters an extraction device (16) and is mixed with an extractant conveyed from an extractant storage tank (19) through a conveying device 8# (18), after extraction, the upper layer organic phase solution is used for back extraction through a conveying device 9# (20), and the lower layer acid solution is conveyed to an acid storage tank (9) for recycling through a conveying device 7# (17); and adding a stripping agent of a stripping storage tank (23) sent by a conveyer device 10# (22) into the organic phase solution after extraction, carrying out stripping in a stripping device (21), sending the organic phase solution at the upper layer of stripping to an extracting agent storage tank (19) for recycling by a conveyer device 11# (24), and sending the liquid at the lower layer of stripping, namely a pure solution containing indium, by a conveyer device 12# (25).

The flue gas that the pyrolysis produced supplies heat for burning furnace device (5) to the flue gas of burning furnace device (5) supplies the heat of pyrolysis device (4) in turn, is provided for leaching device (8) by the waste heat of pyrolysis device (4), and the tail gas that leaching device (8) process produced sends into purifier (12) through conveyor 5# (11) and fully purifies behind the purification unit (12) discharges to the air by discharging device (13).

Example 4

By adopting the method in example 2, the liquid crystal panel was pyrolyzed at 577 ℃, and the residue was leached with sulfuric acid under ultrasonic conditions to obtain a leaching solution containing indium, and the leaching effect was studied. The results are shown in Table 1.

Table 1: record table of leaching orthogonal experiment

Table 1 shows that, when the ultrasonic combined sulfuric acid developed by the present invention is used for leaching after pyrolysis, the indium leaching rate is greater than 92%, which is beneficial to the subsequent indium recycling.

Example 5: pair of extracting agents In₂(SO₄)₃、In(NO₃)₃、InCl₃Effect of extraction of

Preparing indium nitrate, indium sulfate and indium trichloride solutions with different pH values; a50 mL centrifuge tube was charged with 15mL of the In-containing solution and 15mL of the extractant (10mM) prepared In example 1, and shaken at 200rpm for 1 h. And (4) comparing and detecting the In concentration In the liquid phase before and after extraction, and analyzing the effect of the extracting agent on different indium-containing solutions.

TABLE 2 extraction Effect of the extractant on pure indium nitrate, indium sulfate and indium trichloride solutions of different pH

As can be seen from table 2, when the pH is adjusted to 3-6, the extraction efficiency of different indium salts is 99.0-100%, and the extraction efficiency is effectively ensured, when the pH is adjusted to 3-4.

Comparative example 1

The liquid crystal panel is soaked in the organic solution for recovery, and the operation is as follows:

(1) pretreatment: manually disassembling a polarizing film of the liquid crystal panel, and soaking for 60min by using acetone;

(2) adding 0.35g of manganese dioxide into 9.23g of the treated liquid crystal panel, adding 50mL of sulfuric acid solution (2mol/L), and heating in a water bath at 70 ℃ for 100min under the conditions that the ultrasonic power is 700W and the stirring speed is 500 rpm;

the leaching capacity is tested by ICP-OES to be 0.119mg/g, the indium content of leaching residue is 0.019mg/g, and the leaching efficiency is 86.12%;

(3) and (3) extraction: adjusting the leaching solution to 3.32 by using ammonia water, and adding 10mL of extracting agent (the concentration is 0.1mol/L, and the diluent is sulfonated kerosene) and 10mL of leaching solution into a 50mL centrifuge tube;

oscillating at the oscillating speed of 200rpm for 60min at room temperature;

the concentration of the extraction stock solution is 14.02mg/L by ICP-OES, the concentration of the liquid phase after extraction is 1.34mg/L, and the extraction efficiency is 90.4%.

Comparative example 2:

the conventional extractant is researched to recover the liquid crystal panel, and the steps are as follows:

s1: crushing the liquid crystal panel, wherein the granularity is less than 1 cm; placing the broken liquid crystal panel in a pyrolysis furnace for anaerobic pyrolysis at 577 ℃ to realize complete decomposition of the liquid crystal screen and the polarizing film;

s2: soaking the crushed liquid crystal panel obtained after pyrolysis in a sulfuric acid solution, filtering to obtain a sulfuric acid solution soaking solution, and recovering the soaked glass residues for subsequent resource utilization; the concentration of the sulfuric acid solution is 1mol/L, leaching liquor containing indium is obtained, and the pH value is adjusted to 2.93;

s3: extracting and back-extracting the sulfuric acid solution soak solution, and adding 10mL of an extracting agent (the concentration is 0.1mol/L, and the diluent is sulfonated kerosene) and 10mL of leaching liquor into a 50mL centrifuge tube; oscillating at the oscillating speed of 200rpm for 60min at room temperature;

testing the content of indium in the liquid phase before and after leaching by using ICP-OES; the test results are: the original concentration of the indium sulfate solution (pH 2.93) was 16.00mg/L, the concentration of the liquid phase after extraction was 0.38mg/L, and the extraction efficiency was 97.63%.

The preferred embodiments of the present invention have been described in detail, however, the present invention is not limited to the specific details of the above embodiments, and various simple modifications may be made to the technical solution of the present invention within the technical idea of the present invention, and these simple modifications are within the protective scope of the present invention.

It should be noted that the various features described in the above embodiments may be combined in any suitable manner without departing from the scope of the invention. The invention is not described in detail in order to avoid unnecessary repetition.

In addition, any combination of the various embodiments of the present invention is also possible, and the same should be considered as the disclosure of the present invention as long as it does not depart from the spirit of the present invention.