Method for recovering ITO waste target by electrolysis in aqueous solution

Abstract

The embodiment of the present invention discloses a method for electrolyzing and recovering ITO waste targets in an aqueous solution, comprising: using an ITO waste target as an anode, using an ITO waste target or an inert electrode as a cathode, and using an inorganic salt aqueous solution as an electrolyte to form an electrolysis system; applying ultrasonic waves to the electrolysis system, and the electrolysis system performs constant current electrolysis; after the electrolysis is completed, collecting the electrolysis products, dehydrating at a set temperature, and obtaining a mixed powder of indium oxide and tin oxide. The method for electrolyzing and recovering ITO waste targets in an aqueous solution utilizes ultrasonic coupling to electrolyze and recover ITO waste targets in an aqueous solution, and the generated products are tin oxide and indium oxide powders, which can be reused as tin and indium resources; the recovery process conditions are simple and easy to control, easy to operate, high product yield, no harmful gas generation, and can achieve efficient recovery of ITO waste targets and efficient recovery and utilization of indium and tin resources.

Description

Technical Field

[0001] The invention belongs to the technical field of electrochemical metallurgy, and in particular relates to a method for recovering ITO waste targets by electrolysis in an aqueous solution. Background Art

[0002] Indium tin oxide (ITO) is widely used in liquid crystal display and other fields due to its excellent conductivity and light transmittance. However, a large amount of ITO waste is generated during the sintering process of ITO, and in the process of sputtering ITO targets, the utilization rate of ITO is less than 30%, and 70% of ITO remains in the sputtering chamber in the form of sludge, resulting in serious waste of indium resources. Indium is an important and rare resource. The rapid increase in indium resource consumption each year has led to the rapid depletion of indium resources and the rapid rise in prices.

[0003] Recycling indium and tin metals from discarded targets is an important way to save indium resources and efficiently utilize ITO. Currently, the commonly used recycling technologies include pyrometallurgy and hydrometallurgy. However, there are still problems with the existing technologies. For example, pyrometallurgy has high energy consumption, large metal volatilization losses, and large pollution emissions; hydrometallurgy uses various strong acids and organic solvents for extraction, which can achieve a higher recovery rate. However, the use of a large amount of strong acids and organic solvents increases the risk and produces waste acid.

[0004] It is very important to develop new green processes to recover indium and tin from discarded targets. Summary of the invention

[0005] In view of this, some embodiments disclose a method for recovering ITO waste targets by electrolysis in an aqueous solution, the method comprising:

[0006] An electrolytic system is formed by using an ITO waste target as an anode, an ITO waste target or an inert electrode as a cathode, and an inorganic salt aqueous solution as an electrolyte;

[0007] Applying ultrasonic waves to the electrolysis system, so that the electrolysis system performs constant current electrolysis;

[0008] After the electrolysis is completed, the electrolysis products are collected and dehydrated at a set temperature to obtain a mixed powder of indium oxide and tin oxide.

[0009] In some embodiments, the method for recovering ITO waste targets by electrolysis in aqueous solution is disclosed, wherein an anode, a cathode and an electrolyte are placed in an electrolytic cell; the electrolytic cell is placed in an ultrasonic constant temperature water bath device;

[0010] Among them, the ultrasonic constant temperature water bath device includes:

[0011] A constant temperature water bath for setting up and heating the electrolytic cell;

[0012] The ultrasonic generator is arranged at the bottom of the constant temperature water bath and is used to generate ultrasonic waves.

[0013] Some embodiments disclose a method for electrolytically recovering ITO waste targets in an aqueous solution, wherein the inorganic salt is one or a combination of LiCl, NaCl, KCl, NH4Cl, NH4NO3, NH4OH, NaOH, KOH, etc.; the mass concentration of the inorganic salt aqueous solution is 1 to 50 wt.%, and the pH is 6.5 to 7.5.

[0014] In the method for recovering ITO waste targets by electrolysis in aqueous solution disclosed in some embodiments, the power of the ultrasonic wave is 40 to 2000 W, and the frequency of the ultrasonic wave is 20 to 500 KHz.

[0015] In the method for recovering ITO waste targets by electrolysis in aqueous solution disclosed in some embodiments, the temperature of the electrolyte is set to 10-120°C.

[0016] In some embodiments, the method for recovering ITO waste targets by electrolysis in aqueous solution is disclosed, wherein the current density of the constant current electrolysis is 0.01 to 5 A cm -2 .

[0017] In some embodiments of the present invention, the inert electrode of the method for recovering ITO waste targets by electrolysis in aqueous solution includes a graphite electrode, a molybdenum electrode, and a stainless steel electrode.

[0018] In the method for recovering ITO waste targets by electrolysis in aqueous solution disclosed in some embodiments, the dehydration temperature of the electrolysis product is set to 400-800°C.

[0019] The method for recovering ITO waste targets by electrolysis in an aqueous solution disclosed in an embodiment of the present invention utilizes ultrasonic coupling in an aqueous solution to electrolyze and recover ITO waste targets, and the generated products are tin oxide and indium oxide powders, which can be reused as tin and indium resources. The recovery process conditions are simple and easy to control, easy to operate, high in product yield, no harmful gas is generated, and efficient recovery of ITO waste targets can be achieved, and efficient recovery and utilization of indium and tin resources can be achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 Schematic diagram of the device for electrolytic recovery of ITO waste targets in aqueous solution in Example 1. DETAILED DESCRIPTION

[0021] The word "embodiment" used herein as an "exemplary" does not necessarily mean that any embodiment described is superior or better than other embodiments. Performance index tests in the embodiments of the present invention are performed using conventional test methods in the art unless otherwise specified. It should be understood that the terms described in the embodiments of the present invention are only used to describe specific implementation methods and are not intended to limit the contents disclosed in the embodiments of the present invention.

[0022] Unless otherwise specified, the technical and scientific terms used herein have the same meanings as commonly understood by ordinary technicians in the technical field to which the embodiments of the present invention belong; other experimental methods and technical means not specifically specified in the embodiments of the present invention refer to experimental methods and technical means commonly used by ordinary technicians in the field.

[0023] The terms "substantially" and "approximately" used herein are used to describe small fluctuations. For example, they can refer to less than or equal to ±5%, such as less than or equal to ±2%, such as less than or equal to ±1%, such as less than or equal to ±0.5%, such as less than or equal to ±0.2%, such as less than or equal to ±0.1%, such as less than or equal to ±0.05%. The numerical data represented or presented in the range format herein are used only for convenience and brevity, and should therefore be flexibly interpreted as including not only the values ​​clearly listed as the limits of the range, but also all independent values ​​or sub-ranges contained in the range. For example, the numerical range of "1-5%" should be interpreted as including not only the clearly listed values ​​of 1% to 5%, but also the independent values ​​and sub-ranges within the range shown. Therefore, independent values ​​such as 2%, 3.5% and 4% and sub-ranges such as 1%-3%, 2%-4% and 3%-5% are included in this numerical range. This principle also applies to the range of only one numerical value. In addition, such an interpretation applies regardless of the width of the range or the characteristics described.

[0024] In this document, including in the claims, transitional words such as "comprises," "includes," "with," "having," "containing," "involving," "accommodating," etc. are understood to be open-ended, i.e., meaning "including but not limited to." Only the transitional words "consisting of" and "composed of" are closed transitional words.

[0025] In order to better illustrate the present invention, numerous specific details are provided in the specific examples below. It should be understood by those skilled in the art that the present invention can be implemented without certain specific details. In the embodiments, some methods, means, instruments, equipment, etc. well known to those skilled in the art are not described in detail in order to highlight the gist of the present invention.

[0026] Under the premise of no conflict, the technical features disclosed in the embodiments of the present invention may be arbitrarily combined, and the resulting technical solutions belong to the contents disclosed in the embodiments of the present invention.

[0027] In some embodiments, the method for recovering ITO waste targets by electrolysis in an aqueous solution comprises:

[0028] An electrolytic system is formed by using an ITO waste target as an anode, an ITO waste target or an inert electrode as a cathode, and an inorganic salt aqueous solution as an electrolyte;

[0029] Ultrasonic waves are applied to the electrolysis system, and the electrolysis system performs constant current electrolysis. Usually, there are some dissolved gases in the aqueous solution, forming small bubbles. The aqueous solution produces cavitation under the action of ultrasonic waves, causing some small bubbles to burst and generating instantaneous high temperature and high pressure, which can significantly promote the electrochemical electrolysis reaction in the aqueous solution. In addition, the tiny bubbles burst and generate shock waves when the sound pressure exceeds a certain level, breaking the crystallized grains and achieving the effect of grain refinement. Therefore, applying ultrasonic waves to the electrolysis system can produce a coupled synergistic effect on the electrolysis process, which is beneficial to promoting electrochemical electrolysis and achieving the output and refinement of electrolysis products.

[0030] After the electrolysis is completed, the electrolysis products are collected and dehydrated at a set temperature to obtain a mixed powder of indium oxide and tin oxide.

[0031] In some embodiments, the method for recovering ITO waste targets by electrolysis in aqueous solution is disclosed, wherein an anode, a cathode and an electrolyte are placed in an electrolytic cell; the electrolytic cell is placed in an ultrasonic constant temperature water bath device;

[0032] Among them, the ultrasonic constant temperature water bath device includes:

[0033] A constant temperature water bath for setting up and heating the electrolytic cell;

[0034] The ultrasonic generator is arranged at the bottom of the constant temperature water bath and is used to generate ultrasonic waves.

[0035] Some embodiments disclose a method for electrolytically recovering ITO waste targets in an aqueous solution, wherein the inorganic salt is one or a combination of LiCl, NaCl, KCl, NH4Cl, NH4NO3, NH4OH, NaOH, KOH, etc.; the mass concentration of the inorganic salt aqueous solution is 1 to 50 wt.%, and the pH is 6.5 to 7.5.

[0036] In the method for recovering ITO waste targets by electrolysis in aqueous solution disclosed in some embodiments, the power of the ultrasonic wave is 40 to 2000 W, and the frequency of the ultrasonic wave is 20 to 500 KHz.

[0037] In the method for recovering ITO waste targets by electrolysis in aqueous solution disclosed in some embodiments, the temperature of the electrolyte is set to 10-120°C.

[0038] In some embodiments, the method for recovering ITO waste targets by electrolysis in aqueous solution is disclosed, wherein the current density of the constant current electrolysis is 0.01 to 5 A cm -2 .

[0039] In some embodiments of the present invention, the inert electrode of the method for recovering ITO waste targets by electrolysis in aqueous solution includes a graphite electrode, a molybdenum electrode, and a stainless steel electrode.

[0040] In the method for recovering ITO waste targets by electrolysis in aqueous solution disclosed in some embodiments, the dehydration temperature of the electrolysis product is set to 400-800°C.

[0041] Some embodiments disclose a device for recovering ITO waste targets by electrolysis in aqueous solution. Figure 1 Figure 1 is a schematic diagram of the device. Figure 1 In the example, the electrolysis device includes an ultrasonic constant temperature water bath device, which includes a constant temperature water bath and a plurality of ultrasonic field generating sources arranged at the bottom of the constant temperature water bath; a heating carrier is arranged in the constant temperature water bath, an electrolytic cell is arranged in the constant temperature water bath, an aqueous solution electrolyte is arranged in the electrolytic cell, an ITO anode and an ITO / metal cathode are arranged in the aqueous solution electrolyte;

[0042] In the process of electrolytic recovery of ITO waste targets, a constant temperature water bath is set to heat to a set temperature, the electrolyte of the aqueous solution is controlled at a constant temperature, the ultrasonic field generator is started, ultrasonic waves of a predetermined intensity and frequency are generated, the anode and the cathode are respectively connected to a DC power supply, constant current electrolysis is performed under the action of ultrasonic coupling, white flocculent precipitation is continuously generated in the aqueous solution, and after the electrolysis is completed, the electrolysis product is filtered and collected, and further heated and dehydrated to obtain a mixed powder of indium oxide and tin oxide. The product yield is greater than 97%.

[0043] The technical details are further illustrated below in conjunction with embodiments.

[0044] Example 1

[0045] An electrolytic system is formed by using an ITO waste target as an anode, using an ITO waste target as a cathode, and using a 10 wt % NaCl aqueous solution as an electrolyte;

[0046] Ultrasonic waves with a frequency of 40 kHz and a power of 180 W were applied to the electrolysis system, and the electrolysis system was subjected to constant current electrolysis; the electrolysis temperature was 30 °C, and the electrolysis current was 0.1 A cm -2 ;

[0047] After the electrolysis is completed, the electrolysis product is filtered and collected, and the electrolysis product is dehydrated at a temperature of 500° C. to obtain a mixed powder of indium oxide and tin oxide, with a product yield of 98.3%.

[0048] Example 2

[0049] An electrolytic system is formed by using an ITO waste target as an anode, an ITO waste target as a cathode, and a 10wt% NH4Cl+1% NH4OH aqueous solution as an electrolyte;

[0050] Ultrasonic waves with a frequency of 40 kHz and a power of 120 W were applied to the electrolysis system, and the electrolysis system was subjected to constant current electrolysis; the electrolysis temperature was 40 °C, and the electrolysis current was 0.2 A cm -2 ;

[0051] After the electrolysis is completed, the electrolysis product is filtered and collected, and the electrolysis product is dehydrated at a temperature of 600° C. to obtain a mixed powder of indium oxide and tin oxide, with a product yield of 98.1%.

[0052] Example 3

[0053] An electrolytic system was formed by using an ITO waste target as an anode, a molybdenum rod as a cathode, and a 10wt% NH4Cl+1% NH4OH aqueous solution as an electrolyte;

[0054] Ultrasonic waves with a frequency of 40 KHz and a power of 180 W were applied to the electrolysis system, and the electrolysis system was subjected to constant current electrolysis; the electrolysis temperature was 40 ° C, and the electrolysis current was 0.3 A cm -2 ;

[0055] After the electrolysis is completed, the electrolysis product is filtered and collected, and the electrolysis product is dehydrated at a temperature of 500° C. to obtain a mixed powder of indium oxide and tin oxide, with a product yield of 97.7%.

[0056] Example 4

[0057] An electrolytic system is formed by using an ITO waste target as an anode, using an ITO waste target as a cathode, and using a 10 wt % NaCl aqueous solution as an electrolyte;

[0058] Ultrasonic waves with a frequency of 40 kHz and a power of 120 W were applied to the electrolysis system, and the electrolysis system was subjected to constant current electrolysis; the electrolysis temperature was 50 °C, and the electrolysis current was 0.2 A cm -2 ;

[0059] After the electrolysis is completed, the electrolysis product is filtered and collected, and the electrolysis product is dehydrated at a temperature of 600° C. to obtain a mixed powder of indium oxide and tin oxide, with a product yield of 97.9%.

[0060] Example 5

[0061] An electrolytic system is formed by using an ITO waste target as an anode, a molybdenum rod as a cathode, and a 10 wt % KCl aqueous solution as an electrolyte;

[0062] Ultrasonic waves with a frequency of 40 kHz and a power of 180 W were applied to the electrolysis system, and the electrolysis system was subjected to constant current electrolysis; the electrolysis temperature was 40 °C, and the electrolysis current was 0.1 A cm -2 ;

[0063] After the electrolysis is completed, the electrolysis product is filtered and collected, and the electrolysis product is dehydrated at a temperature of 500° C. to obtain a mixed powder of indium oxide and tin oxide, with a product yield of 97.6%.

[0064] Example 6

[0065] An electrolytic system is formed by using an ITO waste target as an anode, a molybdenum rod as a cathode, and a 10 wt % KCl aqueous solution as an electrolyte;

[0066] Ultrasonic waves with a frequency of 40 KHz and a power of 130 W were applied to the electrolysis system, and the electrolysis system was subjected to constant current electrolysis; the electrolysis temperature was 40 ° C, and the electrolysis current was 0.2 A cm -2 ;

[0067] After the electrolysis is completed, the electrolysis product is filtered and collected, and the electrolysis product is dehydrated at a temperature of 600° C. to obtain a mixed powder of indium oxide and tin oxide, with a product yield of 98.2%.

[0068] The method for recovering ITO waste targets by electrolysis in an aqueous solution disclosed in an embodiment of the present invention utilizes ultrasonic coupling in an aqueous solution to electrolyze and recover ITO waste targets, and the generated products are tin oxide and indium oxide powders, which can be reused as tin and indium resources. The recovery process conditions are simple and easy to control, easy to operate, high in product yield, no harmful gas is generated, and efficient recovery of ITO waste targets can be achieved, and efficient recovery and utilization of indium and tin resources can be achieved.

[0069] The technical solutions disclosed in the embodiments of the present invention and the technical details disclosed in the embodiments are merely illustrative of the inventive concept of the present invention and do not constitute a limitation on the technical solutions of the embodiments of the present invention. Any conventional changes, replacements or combinations of the technical details disclosed in the embodiments of the present invention have the same inventive concept as the present invention and are within the protection scope of the claims of the present invention.

Claims

1. A method for recovering ITO waste targets by electrolysis in aqueous solution, characterized in that: The method includes: An electrolytic system is formed by using an ITO waste target as an anode, an ITO waste target or an inert electrode as a cathode, and an inorganic salt aqueous solution as an electrolyte; the inorganic salt is one or a combination of LiCl, NaCl, KCl, NH4Cl, NH4NO3, NH4OH, NaOH, and KOH; the mass concentration of the inorganic salt aqueous solution is 1 to 50 wt.%, and the pH is 6.5 to 7.5; Ultrasonic waves are applied to the electrolysis system, and the electrolysis system performs constant current electrolysis; the current density of the constant current electrolysis is 0.01 to 5 A cm -2 ; After the electrolysis is completed, the electrolysis products are collected and dehydrated at a set temperature to obtain a mixed powder of indium oxide and tin oxide.

2. The method for recovering ITO waste targets by electrolysis in aqueous solution according to claim 1, characterized in that: The anode, the cathode and the electrolyte are placed in an electrolytic cell; the electrolytic cell is placed in an ultrasonic constant temperature water bath device; Wherein, the ultrasonic constant temperature water bath device comprises: A constant temperature water bath for setting up and heating the electrolytic cell; The ultrasonic generator is arranged at the bottom of the constant temperature water bath pot and is used for generating ultrasonic waves.

3. The method for recovering ITO waste targets by electrolysis in aqueous solution according to claim 1 or 2, characterized in that: The power of ultrasound is 40-2000W, and the frequency of ultrasound is 20-500KHz.

4. The method for recovering ITO waste targets by electrolysis in aqueous solution according to claim 1 or 2, characterized in that: The temperature of the electrolyte is set to 10-120°C.

5. The method for recovering ITO waste targets by electrolysis in aqueous solution according to claim 1 or 2, characterized in that: The inert electrodes include graphite electrodes, molybdenum electrodes and stainless steel electrodes.

6. The method for recovering ITO waste targets by electrolysis in aqueous solution according to claim 1 or 2, characterized in that: The dehydration temperature of the electrolysis product is set to 400-800°C.

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