Method for recovering indium from indium-containing anode bag and indium-containing waste

Abstract

The invention discloses a method for recovering indium from an indium-containing anode bag and indium-containing waste materials, and belongs to the technical field of resource recycling and reutilization. The indium-containing anode bag is pyrolyzed, then a pyrolysis precursor, fused salt and indium-containing waste material powder are evenly mixed and calcined, the anode bag not only contains a large amount of indium but also contains a large amount of carbon element, and therefore the indium-containing anode bag can be recycled. The preparation method comprises the following steps: calcining indium in a calcining furnace, effectively improving the reduction effect and reducing the loss rate of indium metal in the calcining process under the combined action with molten salt, respectively recovering and purifying indium-containing scum and indium alloy, carrying out acid leaching on the indium-containing scum, carrying out selective adsorption and desorption on indium by using resin to obtain an indium-containing solution with low impurity content, distilling the indium alloy, and recycling the indium-containing solution. And crude indium is obtained.

Description

Technical Field

[0001] The present invention relates to the technical field of resource recycling and reuse, and particularly relates to a method for recovering indium from indium-containing anode bags and indium-containing waste materials. Background Art

[0002] Indium is widely distributed in many frontier fields such as optical fiber communication, photovoltaic industry, infrared detection technology, and efficient chemical catalysis. However, with the continuous increase in the global demand for indium metal, its scarcity has directly led to a year-on-year increase in market prices, triggering a tense situation in the supply and demand relationship of the indium metal market. The secondary recovery and extraction of indium metal from indium-containing resources have become the mainstream in the market. Indium-containing resources include by-products of lead-zinc-copper smelting, production waste, electronic waste, etc.

[0003] During the electrolysis of indium, metal ions will be precipitated from the anode metal and anode mud will be produced. Therefore, it is necessary to wrap the indium anode plate with an anode bag (usually made of polyester). With the increase in the number of electrolysis times and the adjustment of the electrolysis process, the reaction of the indium anode plate during electrolysis is insufficient, and a large amount of indium metal enters the anode mud, thus adhering to the anode bag, forming an indium-containing anode bag.

[0004] In addition, ITO target cutting waste and waste indium oxide powder are also important sources of indium-containing waste. ITO (indium tin oxide) target is an important material for manufacturing electronic products such as flat panel displays. During the production process, a large amount of ITO target cutting waste and waste indium oxide powder will be produced, and these wastes contain a large amount of indium. Summary of the Invention

[0005] The purpose of the present invention is to overcome the deficiencies of the prior art and provide a method for recovering indium from indium-containing anode bags and indium-containing waste materials. The present invention can effectively recover indium from indium-containing anode bags and indium-containing waste powder. At the same time, the elements in the indium-containing anode bag promote the reduction process, promote each other, and recover the dross and alloy respectively, effectively improving the recovery rate of indium metal.

[0006] To achieve the above purpose, the technical solution adopted by the present invention is as follows:

[0007] A method for recovering indium from indium-containing anode bags and indium-containing waste materials, comprising the following steps:

[0008] Crush the indium-containing anode bag and pyrolyze it under a nitrogen atmosphere to obtain a pyrolysis precursor;

[0009] Mix the pyrolysis precursor, molten salt, and indium-containing waste powder evenly and calcine to obtain indium-containing dross and indium alloy;

[0010] Distill the indium alloy to obtain crude indium;

[0011] Leach the indium-containing dross with a sulfuric acid solution to obtain a leachate;

[0012] Adjust the pH of the leaching solution to 1.8 - 2.2, and pass it through the adsorption resin at a flow rate of 4 - 6 BV / h. Then, use the sulfuric acid solution to desorb the adsorption resin at a rate of 0.4 - 0.8 BV / h to obtain an indium-containing solution.

[0013] In the present invention, the indium-containing anode bag is pyrolyzed, and then the pyrolysis precursor, molten salt, and indium-containing waste powder are mixed evenly and calcined. The anode bag not only contains a large amount of indium but also a large amount of carbon element, which acts together with the molten salt during the calcination process, effectively improving the reduction effect and reducing the indium metal loss rate. Then, the indium-containing dross and indium alloy are separately recovered and purified. Among them, the indium-containing dross is acid-leached, and then the resin is used for selective adsorption and desorption of indium to obtain an indium-containing solution with low impurity content. The indium alloy is distilled to obtain crude indium.

[0014] The present invention can effectively recover indium from the indium-containing anode bag and indium-containing waste powder. At the same time, the elements in the indium-containing anode bag promote the reduction process, promote each other, and the dross and alloy are separately recovered, effectively improving the recovery rate of indium metal.

[0015] As a preferred embodiment of the present invention, the pyrolysis temperature is 350 - 400 °C, and the pyrolysis time is 1 - 4 h.

[0016] As a preferred embodiment of the present invention, the calcination temperature is 1000 - 1200 °C, and the calcination time is 6 - 8 h.

[0017] As a preferred embodiment of the present invention, the mass ratio of the pyrolysis precursor, molten salt, and indium-containing waste powder is (10 - 20):(1 - 5):(50 - 100). Especially when the mass ratio of the three is controlled within this range, the recovery rate can be more effectively improved, indium metal loss can be avoided, and the reduction effect can be improved.

[0018] As a preferred embodiment of the present invention, the molten salt includes at least one of alumina, sodium carbonate, quartz sand, and borax.

[0019] As a preferred embodiment of the present invention, the distillation temperature is 1000 - 1200 °C, and the time is 6 - 8 h.

[0020] As a preferred embodiment of the present invention, the solid-liquid ratio of the indium-containing dross to the sulfuric acid solution is 1:(4 - 6).

[0021] As a preferred embodiment of the present invention, the leaching temperature is 45 - 55 °C, and the time is 4 - 6 h.

[0022] As a preferred embodiment of the present invention, the concentration of the sulfuric acid solution is 2 - 6 mol / L.

[0023] As a preferred embodiment of the present invention, the adsorption resin includes at least one of D418 amino phosphoric acid resin and macroporous amidoxime resin.

[0024] As a preferred embodiment of the present invention, the main metal element contents of the indium-containing anode bag (made of polyester) are as follows: In 0.05 - 1.28%, Sn 1.5 - 5.9%, Fe 3.43 - 8.16%, Pb 3 - 5%, Bi 0.2 - 3%.

[0025] As a preferred embodiment of the present invention, the indium content in the indium-containing waste powder is 30 - 40%.

[0026] The beneficial effects of the present invention are as follows: The indium-containing anode bag of the present invention is pyrolyzed, and then the pyrolysis precursor, molten salt and indium-containing waste powder are mixed evenly and calcined. The anode bag not only contains a large amount of indium, but also a large amount of carbon element, which acts together with the molten salt during the calcination process, effectively improving the reduction effect and reducing the indium metal loss rate. Then, the indium-containing dross and indium alloy are separately recovered and purified. Among them, the indium-containing dross is acid-leached, and then the resin is used for selective adsorption and desorption of indium to obtain an indium-containing solution with low impurity content, and the indium alloy is distilled to obtain crude indium. Description of the Drawings

[0027] Figure 1 The indium-containing waste for Example 1. Detailed Embodiments

[0028] To make the objectives, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below. Apparently, the described embodiments are some, but not all, of the embodiments of the present application. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present application without creative efforts shall fall within the scope of protection of the present application.

[0029] In the present application, among the technical features described in an open-ended manner, a closed technical solution composed of the listed features is included, and an open technical solution including the listed features is also included.

[0030] In the present application, regarding the numerical range, unless otherwise specified, the above numerical range is considered continuous and includes the minimum value and maximum value of the range, as well as each value between such minimum value and maximum value. Further, when the range refers to an integer, each integer between the minimum value and maximum value of the range is included. In addition, when multiple ranges are provided to describe features or characteristics, the ranges can be combined. In other words, unless otherwise specified, all ranges disclosed herein should be understood to include any and all sub-ranges subsumed therein.

[0031] In this application, there is no particular limitation on the specific dispersion and stirring treatment methods.

[0032] Unless otherwise specified, the component raw materials or instruments used in the embodiments and comparative examples of the present invention are all commercially available raw materials or instruments, and the component raw materials used in each parallel experiment are of the same kind.

[0033] Example 1

[0034] A method for recovering indium from indium-containing anode bags and indium-containing waste, comprising the following steps:

[0035] (1) Crush the indium-containing anode bag to 100 mesh to obtain indium-containing anode bag powder;

[0036] Load the indium-containing anode bag powder into a corundum boat, place it in a tube furnace, introduce nitrogen at a flow rate of 5 L / min, heat up to 400 °C at a rate of 10 °C / min, and pyrolyze at 400 °C for 2 h to obtain a pyrolysis precursor;

[0037] Among them, the main metal element contents of the indium-containing anode bag are: In 1.09%, Sn 1.74%, Fe 5.72%, Pb 4.29%, Bi 2.95%.

[0038] (2) Remove the particulate matter from the indium-containing waste (a mixture of ITO target cutting waste and waste indium oxide powder) as shown in Figure 1 and sieve it to obtain indium-containing waste powder; among them, the indium content in the indium-containing waste powder is 30.32%;

[0039] Mix the pyrolysis precursor, borax and indium-containing waste powder evenly according to a mass ratio of 10:1:50, calcine at 1000 °C for 6 h, skim the surface scum (i.e., indium-containing scum), and obtain indium-containing scum and indium alloy respectively;

[0040] (3) Load the indium alloy into a graphite boat, then place it in a vacuum distillation furnace, evacuate to a vacuum degree of 5 Pa, and distill at 1200 °C for 6 h to obtain crude indium;

[0041] (4) Leach the indium-containing scum with a 5 mol / L sulfuric acid solution at 50 °C for 5 h to obtain a leachate; the solid-liquid ratio of the indium-containing scum to the sulfuric acid solution is 1:5.

[0042] (5) Adjust the pH of the leachate to 2 with a 4 mol / L sulfuric acid solution, pass it through a D418 amino phosphoric acid resin with a height of 500 mm at a flow rate of 5 BV / h, and then elute the adsorption resin with a sulfuric acid solution at a rate of 0.5 BV / h to obtain an indium-containing solution.

[0043] Example 2

[0044] A method for recovering indium from indium-containing anode bags and indium-containing waste, comprising the following steps:

[0045] (1) Crush the indium-containing anode bag to 100 mesh to obtain indium-containing anode bag powder;

[0046] Load the indium-containing anode bag powder into a corundum boat, place it in a tubular furnace, introduce nitrogen at a flow rate of 5 L / min, heat up to 400 °C at a rate of 10 °C / min, and pyrolyze at 400 °C for 2 h to obtain a pyrolysis precursor;

[0047] Among them, the main metal element contents of the indium-containing anode bag are: In 1.09%, Sn 1.74%, Fe 5.72%, Pb 4.29%, Bi 2.95%.

[0048] (2) Remove the particulate matter from the indium-containing waste (a mixture of ITO target cutting waste and waste indium oxide powder) as shown in Figure 1 and sieve it to obtain indium-containing waste powder; among them, the indium content in the indium-containing waste powder is 30.32%;

[0049] Mix the pyrolysis precursor, borax and indium-containing waste powder evenly according to a mass ratio of 20:5:100, calcine at 1000 °C for 6 h, skim the surface scum (i.e., indium-containing scum), and obtain indium-containing scum and indium alloy respectively;

[0050] (3) Load the indium alloy into a graphite boat, then place it in a vacuum distillation furnace, evacuate to a vacuum degree of 5 Pa, and distill at 1200 °C for 6 h to obtain crude indium;

[0051] (4) Leach the indium-containing scum with a 5 mol / L sulfuric acid solution at 50 °C for 5 h to obtain a leachate; the solid-liquid ratio of the indium-containing scum to the sulfuric acid solution is 1:5.

[0052] (5) Adjust the pH of the leachate to 2 with a 4 mol / L sulfuric acid solution, pass it through a D418 amino phosphonic acid resin with a height of 500 mm at a flow rate of 5 BV / h, and then elute the adsorption resin with a sulfuric acid solution at a rate of 0.5 BV / h to obtain an indium-containing solution.

[0053] Example 3

[0054] A method for recovering indium from indium-containing anode bags and indium-containing waste, comprising the following steps:

[0055] (1) Crush the indium-containing anode bag to 100 mesh to obtain indium-containing anode bag powder;

[0056] Load the indium-containing anode bag powder into a corundum boat, place it in a tubular furnace, introduce nitrogen at a flow rate of 5 L / min, heat up to 400 °C at a rate of 10 °C / min, and pyrolyze at 400 °C for 2 h to obtain a pyrolysis precursor;

[0057] Among them, the main metal element contents of the indium-containing anode bag are: In 1.09%, Sn 1.74%, Fe 5.72%, Pb 4.29%, Bi 2.95%.

[0058] (2) Remove the particulate matters from the indium-containing waste material (a mixture of ITO target cutting waste and waste indium oxide powder) as shown in Figure 1 and sieve it to obtain indium-containing waste material powder; among them, the indium content in the indium-containing waste material powder is 30.32%;

[0059] Mix the pyrolysis precursor, borax and indium-containing waste material powder evenly according to the mass ratio of 10:1:50, calcine at 1200 °C for 6 h, fish out the surface scum (i.e., indium-containing scum), and obtain indium-containing scum and indium alloy respectively;

[0060] (3) Load the indium alloy into a graphite boat, then place it in a vacuum distillation furnace, evacuate to a vacuum degree of 5 Pa, and distill at 1200 °C for 6 h to obtain crude indium;

[0061] (4) Leach the indium-containing scum with a 5 mol / L sulfuric acid solution at 50 °C for 5 h to obtain a leaching solution; the solid-liquid ratio of the indium-containing scum to the sulfuric acid solution is 1:5.

[0062] (5) Adjust the pH of the leaching solution to 2 with a 4 mol / L sulfuric acid solution, pass it through a D418 amino phosphonic acid resin with a height of 500 mm at a flow rate of 5 BV / h, and then elute the adsorption resin with a sulfuric acid solution at a rate of 0.5 BV / h to obtain an indium-containing solution.

[0063] Comparative Example 1

[0064] A method for recovering indium from an indium-containing anode bag and indium-containing waste material, comprising the following steps:

[0065] (1) Crush the indium-containing anode bag to 100 meshes to obtain indium-containing anode bag powder;

[0066] Load the indium-containing anode bag powder into a corundum boat, place it in a tube furnace, introduce nitrogen at a flow rate of 5 L / min, heat up to 400 °C at a rate of 10 °C / min, and pyrolyze at 400 °C for 2 h to obtain a pyrolysis precursor;

[0067] Among them, the main metal element contents of the indium-containing anode bag are: In 1.09%, Sn 1.74%, Fe 5.72%, Pb 4.29%, Bi 2.95%.

[0068] (2) Remove the particulate matters from the indium-containing waste material (a mixture of ITO target cutting waste and waste indium oxide powder) as shown in Figure 1 and sieve it to obtain indium-containing waste material powder; among them, the indium content in the indium-containing waste material powder is 30.32%;

[0069] Mix the pyrolysis precursor, borax and indium-containing waste powder evenly according to the mass ratio of 50:1:50, calcine at 1000 °C for 6 h, skim the surface scum (i.e., indium-containing scum), and obtain indium-containing scum and indium alloy respectively;

[0070] (3) Load the indium alloy into a graphite boat, then place it in a vacuum distillation furnace, evacuate to a vacuum degree of 5 Pa, and distill at 1200 °C for 6 h to obtain crude indium;

[0071] (4) Leach the indium-containing scum with 5 mol / L sulfuric acid solution at 50 °C for 5 h to obtain a leaching solution; the solid-liquid ratio of the indium-containing scum to the sulfuric acid solution is 1:5.

[0072] (5) Adjust the pH of the leaching solution to 2 with 4 mol / L sulfuric acid solution, pass it through a D418 amino phosphoric acid resin with a height of 500 mm at a flow rate of 5 BV / h, and then elute the adsorption resin with sulfuric acid solution at a rate of 0.5 BV / h to obtain an indium-containing solution.

[0073] Comparative Example 2

[0074] A method for recovering indium from indium-containing anode bags and indium-containing waste, comprising the following steps:

[0075] (1) Crush the indium-containing anode bag to 100 meshes to obtain indium-containing anode bag powder;

[0076] Load the indium-containing anode bag powder into a corundum boat, place it in a tubular furnace, introduce nitrogen at a flow rate of 5 L / min, heat up to 400 °C at a rate of 10 °C / min, and pyrolyze at 400 °C for 2 h to obtain a pyrolysis precursor;

[0077] Among them, the main metal element contents of the indium-containing anode bag are: In 1.09%, Sn 1.74%, Fe 5.72%, Pb 4.29%, Bi 2.95%.

[0078] (2) Remove the particulate matter from the indium-containing waste (a mixture of ITO target cutting waste and waste indium oxide powder) as shown in Figure 1 , screen it to obtain indium-containing waste powder; among them, the indium content in the indium-containing waste powder is 30.32%;

[0079] Mix the pyrolysis precursor, borax and indium-containing waste powder evenly according to the mass ratio of 5:10:100, calcine at 1000 °C for 6 h, skim the surface scum (i.e., indium-containing scum), and obtain indium-containing scum and indium alloy respectively;

[0080] (3) Load the indium alloy into a graphite boat, then place it in a vacuum distillation furnace, evacuate to a vacuum degree of 5 Pa, and distill at 1200 °C for 6 h to obtain crude indium;

[0081] (4) Leach the indium-containing dross with 5 mol / L sulfuric acid solution at 50 °C for 5 h to obtain a leachate; the solid-liquid ratio of the indium-containing dross to the sulfuric acid solution is 1:5.

[0082] (5) Adjust the pH of the leachate to 2 with 4 mol / L sulfuric acid solution, pass it through a D418 amino phosphoric acid resin with a height of 500 mm at a flow rate of 5 BV / h, and then elute the adsorbed resin with sulfuric acid solution at a rate of 0.5 BV / h to obtain an indium-containing solution.

[0083] Comparative Example 3

[0084] A method for recovering indium from indium-containing anode bags and indium-containing waste materials, comprising the following steps:

[0085] (1) Crush the indium-containing anode bag to 100 mesh to obtain indium-containing anode bag powder;

[0086] Load the indium-containing anode bag powder into a corundum boat, place it in a tube furnace, introduce nitrogen at a flow rate of 5 L / min, heat it to 400 °C at a rate of 10 °C / min, and pyrolyze it at 400 °C for 2 h to obtain a pyrolysis precursor;

[0087] Among them, the main metal element contents of the indium-containing anode bag are: In 1.09%, Sn 1.74%, Fe 5.72%, Pb 4.29%, Bi 2.95%.

[0088] (2) Remove the particulate matter from the indium-containing waste material (a mixture of ITO target cutting waste and waste indium oxide powder) as shown in Figure 1 and sieve it to obtain indium-containing waste powder; among them, the indium content in the indium-containing waste powder is 30.32%;

[0089] Mix the pyrolysis precursor, borax and indium-containing waste powder evenly according to the mass ratio of 10:1:50, calcine it at 800 °C for 6 h, skim the surface dross (i.e., indium-containing dross), and obtain indium-containing dross and indium alloy respectively;

[0090] (3) Load the indium alloy into a graphite boat, and then place it in a vacuum distillation furnace, evacuate to a vacuum degree of 5 Pa, and distill it at 1200 °C for 6 h to obtain crude indium;

[0091] (4) Leach the indium-containing dross with 5 mol / L sulfuric acid solution at 50 °C for 5 h to obtain a leachate; the solid-liquid ratio of the indium-containing dross to the sulfuric acid solution is 1:5.

[0092] (5) Adjust the pH of the leachate to 2 with 4 mol / L sulfuric acid solution, pass it through a D418 amino phosphoric acid resin with a height of 500 mm at a flow rate of 5 BV / h, and then elute the adsorbed resin with sulfuric acid solution at a rate of 0.5 BV / h to obtain an indium-containing solution.

[0093] Comparative Example 4

[0094] A method for recovering indium from indium-containing anode bags and indium-containing waste, comprising the following steps:

[0095] (1) Crush the indium-containing anode bag to 100 mesh to obtain indium-containing anode bag powder;

[0096] Load the indium-containing anode bag powder into a corundum boat, place it in a tubular furnace, introduce nitrogen at a flow rate of 5 L / min, heat it to 400 °C at a rate of 10 °C / min, and pyrolyze it at 400 °C for 2 h to obtain a pyrolysis precursor;

[0097] Among them, the main metal element contents of the indium-containing anode bag are: In 1.09%, Sn 1.74%, Fe 5.72%, Pb 4.29%, Bi 2.95%.

[0098] (2) Remove the particulate matter from the indium-containing waste (a mixture of ITO target cutting waste and waste indium oxide powder) as shown in Figure 1 , screen it to obtain indium-containing waste powder; among them, the indium content in the indium-containing waste powder is 30.32%;

[0099] Mix the pyrolysis precursor, borax and indium-containing waste powder evenly according to a mass ratio of 10:1:50, calcine it at 1400 °C for 6 h, skim the surface scum (i.e., indium-containing scum), and obtain indium-containing scum and indium alloy respectively;

[0100] (3) Load the indium alloy into a graphite boat, then place it in a vacuum distillation furnace, evacuate to a vacuum degree of 5 Pa, and distill it at 1200 °C for 6 h to obtain crude indium;

[0101] (4) Leach the indium-containing scum with a 5 mol / L sulfuric acid solution at 50 °C for 5 h to obtain a leachate; the solid-liquid ratio of the indium-containing scum to the sulfuric acid solution is 1:5.

[0102] (5) Adjust the pH of the leachate to 2 with a 4 mol / L sulfuric acid solution, pass it through a D418 amino phosphoric acid resin with a height of 500 mm at a flow rate of 5 BV / h, and then elute the adsorption resin with a sulfuric acid solution at a rate of 0.5 BV / h to obtain an indium-containing solution.

[0103] Comparative Example 5

[0104] A method for recovering indium from indium-containing anode bags and indium-containing waste, comprising the following steps:

[0105] (1) Crush the indium-containing anode bag to 100 mesh to obtain indium-containing anode bag powder;

[0106] Put the indium-containing anode bag powder into a corundum boat, place it in a tube furnace, introduce nitrogen at a flow rate of 5 L / min, heat it to 400 °C at a rate of 10 °C / min, and pyrolyze it at 400 °C for 2 h to obtain a pyrolysis precursor;

[0107] Among them, the main metal element contents of the indium-containing anode bag are: In 1.09%, Sn 1.74%, Fe 5.72%, Pb 4.29%, Bi 2.95%.

[0108] (2) Remove the particulate matter from the indium-containing waste (a mixture of ITO target cutting waste and waste indium oxide powder) as shown in Figure 1 , screen it to obtain indium-containing waste powder; among them, the indium content in the indium-containing waste powder is 30.32%;

[0109] Mix the pyrolysis precursor, borax and indium-containing waste powder evenly according to the mass ratio of 10:1:50, calcine it at 1000 °C for 6 h, skim the surface scum (i.e., indium-containing scum), and obtain indium-containing scum and indium alloy respectively;

[0110] (3) Put the indium alloy into a graphite boat, then place it in a vacuum distillation furnace, evacuate to a vacuum degree of 5 Pa, and distill it at 1200 °C for 6 h to obtain crude indium;

[0111] (4) Leach the indium-containing scum with a 5 mol / L sulfuric acid solution at 50 °C for 5 h to obtain a leaching solution; the solid-liquid ratio of the indium-containing scum to the sulfuric acid solution is 1:5.

[0112] (5) Adjust the pH of the leaching solution to 1 with a 4 mol / L sulfuric acid solution, pass it through a D418 amino phosphoric acid resin with a height of 500 mm at a flow rate of 5 BV / h, and then elute the adsorption resin with a sulfuric acid solution at a rate of 0.5 BV / h to obtain an indium-containing solution.

[0113] Comparative Example 6

[0114] A method for recovering indium from indium-containing anode bags and indium-containing waste, comprising the following steps:

[0115] (1) Crush the indium-containing anode bag to 100 meshes to obtain indium-containing anode bag powder;

[0116] Put the indium-containing anode bag powder into a corundum boat, place it in a tube furnace, introduce nitrogen at a flow rate of 5 L / min, heat it to 400 °C at a rate of 10 °C / min, and pyrolyze it at 400 °C for 2 h to obtain a pyrolysis precursor;

[0117] Among them, the main metal element contents of the indium-containing anode bag are: In 1.09%, Sn 1.74%, Fe 5.72%, Pb 4.29%, Bi 2.95%.

[0118] (2) Remove the particulate matter from the indium-containing waste (a mixture of ITO target cutting waste and waste indium oxide powder) as shown in Figure 1 , and sieve it to obtain indium-containing waste powder; among them, the indium content in the indium-containing waste powder is 30.32%;

[0119] Mix the pyrolysis precursor, borax and indium-containing waste powder evenly according to the mass ratio of 10:1:50, calcine at 1000 °C for 6 h, skim the surface scum (i.e., indium-containing scum), and obtain indium-containing scum and indium alloy respectively;

[0120] (3) Load the indium alloy into a graphite boat, then place it in a vacuum distillation furnace, evacuate to a vacuum degree of 5 Pa, and distill at 1200 °C for 6 h to obtain crude indium;

[0121] (4) Leach the indium-containing scum with a 5 mol / L sulfuric acid solution at 50 °C for 5 h to obtain a leachate; the solid-liquid ratio of the indium-containing scum to the sulfuric acid solution is 1:5.

[0122] (5) Adjust the pH of the leachate to 3 with a 4 mol / L sulfuric acid solution, pass it through a D418 amino phosphoric acid resin with a height of 500 mm at a flow rate of 5 BV / h, and then elute the adsorption resin with a sulfuric acid solution at a rate of 0.5 BV / h to obtain an indium-containing solution.

[0123] Test example

[0124] Among them, the purity of the crude indium and the total impurities of the indium-containing solution obtained in the examples and comparative examples are shown in Table 1.

[0125] Table 1

[0126] Purity of crude indium / % Total impurities in indium-containing solution / ppm Example 1 99.98 ＜200 Example 2 99.98 ＜200 Example 3 99.90 ＜1000 Comparative Example 1 99.50 ＜1000 Comparative Example 2 99.54 ＜5000 Comparative Example 3 98.05 ＜20000 Comparative Example 4 98.10 ＜10000 Comparative Example 5 98.45 ＜1000 Comparative Example 6 98.98 ＜2000

[0127] It can be seen from Table 1 that in the present invention, the indium-containing anode bag is pyrolyzed, and then the pyrolysis precursor, molten salt and indium-containing waste powder are mixed evenly and calcined. The anode bag not only contains a large amount of indium, but also a large amount of carbon elements, which act together with the molten salt during the calcination process, effectively improving the reduction effect and reducing the indium metal loss rate. Then, the indium-containing scum and indium alloy are separately recovered and purified. Among them, the indium-containing scum is acid-leached, and then the indium is selectively adsorbed and eluted by resin to obtain an indium-containing solution with low impurity content, and the indium alloy is distilled to obtain crude indium.

[0128] 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 the protection scope of the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. A method for recovering indium from indium-containing anode bags and indium-containing waste materials, characterized in that, It includes the following steps: Crush the indium-containing anode bag and pyrolyze it under a nitrogen atmosphere to obtain a pyrolysis precursor; Mix the pyrolysis precursor, molten salt and indium-containing waste powder evenly and calcine to obtain indium-containing dross and indium alloy; Distill the indium alloy to obtain crude indium; Leach the indium-containing dross with a sulfuric acid solution to obtain a leachate; Adjust the pH of the leachate to 1.8 - 2.2, pass it through the adsorption resin at a flow rate of 4 - 6 BV / h, and then desorb the adsorption resin with a sulfuric acid solution at a rate of 0.4 - 0.8 BV / h to obtain an indium-containing solution.

2. The method for recovering indium from indium-containing anode bags and indium-containing waste materials according to claim 1, wherein The pyrolysis temperature is 350 - 400 °C and the pyrolysis time is 1 - 4 h.

3. The method for recovering indium from indium-containing anode bags and indium-containing waste materials according to claim 1, characterized in that, The calcination temperature is 1000 - 1200 °C and the calcination time is 6 - 8 h.

4. The method for recovering indium from indium-containing anode bags and indium-containing waste materials according to claim 1, characterized in that, The mass ratio of the pyrolysis precursor, molten salt and indium-containing waste powder is (10 - 20):(1 - 5):(50 - 100).

5. The method for recovering indium from indium-containing anode bags and indium-containing waste materials according to claim 1, characterized in that, The molten salt includes at least one of alumina, sodium carbonate, quartz sand, and borax.

6. The method for recovering indium from indium-containing anode bags and indium-containing waste materials according to claim 1, wherein The distillation temperature is 1000 - 1200 °C and the time is 6 - 8 h.

7. The method for recovering indium from indium-containing anode bags and indium-containing waste materials according to claim 1, characterized in that The solid-liquid ratio of the indium-containing dross to the sulfuric acid solution is 1:(4 - 6).

8. The method for recovering indium from indium-containing anode bags and indium-containing waste materials according to claim 1, characterized in that, The leaching temperature is 45 - 55 °C and the time is 4 - 6 h.

9. The method for recovering indium from indium-containing anode bags and indium-containing waste materials according to claim 1, characterized in that, The concentration of the sulfuric acid solution is 2 - 6 mol / L.

10. The method for recovering indium from indium-containing anode bags and indium-containing waste materials according to claim 1, characterized in that, The adsorption resin includes at least one of D418 amino phosphoric acid resin and macroporous amidoxime resin.

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