Method for recovering indium from indium-containing material

Abstract

The invention discloses a method for recovering indium from an indium-containing material, and belongs to the technical field of resource recycling and reutilization. Indium-containing material powder is subjected to wet leaching with a sulfuric acid solution, the pH value is adjusted to 3-5 with caustic soda flakes, part of impurity metal and indium can be selectively separated, preliminary treatment is conducted, indium is effectively enriched, and the recovery rate of indium is increased. Then high-temperature smelting reduction is carried out in the presence of a reducing agent and a slag former, metal oxide is reduced into metal, meanwhile, part of sulfur elements can be removed, then halogenation refining is carried out, and directional impurity removal is carried out by utilizing the fact that the affinity of part of metal impurities and halogenated elements is larger than that of indium metal; the indium metal is purified by utilizing different saturated vapor pressures of the indium metal and other metals through vacuum distillation, the whole process is simple to operate, and the indium metal recovery rate is high.

Description

Technical Field

[0001] The invention relates to the technical field of resource recovery and reuse, and in particular to a method for recovering indium from indium-containing materials. Background Art

[0002] Indium, a rare metal, has good ductility, low melting point, high boiling point, high conductivity, strong corrosion resistance, and soft material. It is widely used in aerospace, radio and electronics industries, medical care, national defense, high-tech, energy and other fields.

[0003] ITO target, i.e. indium tin oxide target, is a ceramic target composed of indium (In) and tin (Sn) oxides. This target has excellent conductivity, transparency and good processing performance, so it is widely used in the field of thin film preparation, especially in liquid crystal display (LCD), touch screen, solar cell and various types of coated glass. When producing ITO target, the utilization rate is 70%, and the residual waste contains a high indium content and has a very high recycling value. Wet leaching is often used to separate indium from other impurity metals, but the presence of impurities such as tin and bismuth leads to a low indium recovery rate. Summary of the invention

[0004] The purpose of the present invention is to overcome the shortcomings of the prior art and provide a method for recovering indium from indium-containing materials, which can effectively recover indium metal.

[0005] To achieve the above object, the technical solution adopted by the present invention is:

[0006] A method for recovering indium from an indium-containing material comprises the following steps:

[0007] (1) crushing the indium-containing material to obtain indium-containing material powder;

[0008] (2) leaching the indium-containing material powder with a sulfuric acid solution, adding caustic soda to adjust the pH to 3-5, filtering, and obtaining a filter residue;

[0009] (3) uniformly mixing the filter residue, the reducing agent, and the slag-forming agent, and smelting the mixture to obtain an indium-containing alloy;

[0010] (4) adding an indium-containing alloy, a halogenating agent, and a softening agent into a smelting furnace, smelting, and obtaining an indium ingot;

[0011] (5) Vacuum distill the indium ingot to obtain refined indium.

[0012] The invention wet-leaches indium-containing material powder with sulfuric acid solution, uses caustic soda to adjust the pH to 3-5, can selectively separate part of the impurity metal and indium, performs preliminary treatment, effectively enriches indium, and then performs high-temperature smelting reduction in the presence of a reducing agent and a slag-forming agent to reduce the metal oxide to metal, and simultaneously removes part of the sulfur element, and then performs halogenation refining, utilizes the affinity of part of the metal impurities to the halogenated element to be greater than the affinity of the indium metal, to remove impurities in a targeted manner, and utilizes the different saturated vapor pressures of the indium metal and other metals through vacuum distillation to purify the indium metal. The whole process is simple to operate and has a high recovery rate of the indium metal.

[0013] As a preferred embodiment of the present invention, the indium-containing material is derived from at least one of ITO waste and indium-containing semiconductor electronic waste.

[0014] As a preferred embodiment of the present invention, the indium content in the indium-containing material is 1-10%, and the method of the present invention has a better effect on the material with an indium content of 1-10%.

[0015] As a preferred embodiment of the present invention, the indium-containing material mainly includes the following components: In 1-10%, Sn20-40%, Bi 5-20%, Zn 1-2%, Fe 2-10%, Pb 0.8-1.2%, Cu 1-5%. In particular, when the main components of the indium-containing material are in this ratio, it is more suitable for the method of the present invention, and can carry out targeted impurity removal of various complex metals, effectively improving the purity and recovery rate of indium metal.

[0016] As a preferred embodiment of the present invention, the particle size of the indium-containing material powder is 30-50 meshes.

[0017] As a preferred embodiment of the present invention, the solid-to-liquid ratio of the indium-containing material powder to the sulfuric acid solution is 1 g: (4-6) mL.

[0018] As a preferred embodiment of the present invention, the concentration of the sulfuric acid solution is 5 to 8 wt%;

[0019] The leaching temperature is 75-85° C. and the leaching time is 2-5 hours.

[0020] As a preferred embodiment of the present invention, the mass ratio of the filter residue, the reducing agent and the slag-forming agent is (10-20): (1-3): (1-5). In particular, when the ratio of the filter residue, the reducing agent and the slag-forming agent is controlled within this range, the purity and recovery rate of indium metal can be more effectively improved.

[0021] As a preferred embodiment of the present invention, the reducing agent includes at least one of anthracite, coke, and flour;

[0022] The slag-forming agent includes at least one of sodium chloride, potassium carbonate, sodium carbonate, quartz sand and borax.

[0023] As a preferred embodiment of the present invention, the smelting temperature in step (3) is 800-1200° C. and the smelting time is 6-8 hours.

[0024] As a preferred embodiment of the present invention, the mass ratio of the indium-containing alloy, the halogenating agent, and the softening agent is (100-150): (1-5): (5-10). In particular, when the mass ratio of the indium-containing alloy, the halogenating agent, and the softening agent is controlled within this range, the purity and recovery rate of the indium metal can be more effectively improved.

[0025] As a preferred embodiment of the present invention, the softener includes at least one of glycerol, ethylene glycol, and sorbitol;

[0026] The halogenating agent includes at least one of ammonium chloride, zinc chloride and chlorine.

[0027] As a preferred embodiment of the present invention, the smelting temperature in step (4) is 300-400° C., and the smelting time is 1-4 hours.

[0028] As a preferred embodiment of the present invention, the vacuum distillation temperature is 1000-1200° C. and the time is 6-10 hours.

[0029] The beneficial effects of the present invention are as follows: the present invention wet-leaches indium-containing material powder with a sulfuric acid solution, uses caustic soda to adjust the pH to 3-5, can selectively separate part of the impurity metals and indium, performs preliminary treatment, effectively enriches indium, and then performs high-temperature smelting reduction in the presence of a reducing agent and a slag-forming agent to reduce the metal oxide to a metal, and simultaneously removes part of the sulfur element, and then performs halogenation refining, utilizes the affinity of part of the metal impurities to the halogenated element to be greater than the affinity of the indium metal, to perform directional impurity removal, utilizes the different saturated vapor pressures of the indium metal and other metals through vacuum distillation, to purify the indium metal, the whole process is simple to operate, and the recovery rate of the indium metal is high. DETAILED DESCRIPTION

[0030] In order to make the purpose, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application are described clearly and completely below. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present application.

[0031] In the present application, the technical features described in an open manner include closed technical solutions composed of the listed features, and also include open technical solutions containing the listed features.

[0032] In this application, when it comes to numerical ranges, unless otherwise specified, the above numerical ranges are deemed to be continuous and include the minimum and maximum values ​​of the range, as well as each value between such minimum and maximum values. Further, when a range refers to an integer, each integer between the minimum and maximum values ​​of the range is included. In addition, when multiple ranges are provided to describe features or characteristics, the ranges can be merged. In other words, unless otherwise specified, all ranges disclosed herein should be understood to include any and all subranges included therein.

[0033] In the present application, there is no particular limitation on the specific dispersion and stirring treatment methods.

[0034] Unless otherwise specified, the components, 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 components and raw materials used in each parallel experiment are all of the same kind.

[0035] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0036] The following examples are provided to facilitate understanding of the present invention. These examples are not provided to limit the scope of the claims.

[0037] Example 1

[0038] A method for recovering indium from an indium-containing material comprises the following steps:

[0039] (1) crushing the indium-containing material into 50 meshes using a crusher to obtain indium-containing material powder;

[0040] The indium-containing material mainly includes the following components: In 8.62%, Sn 35.83%, Bi 15.21%, Zn 1.42%, Fe 2.19%, Pb 0.85%, and Cu 1.58%.

[0041] (2) adding indium-containing material powder and sulfuric acid solution into a leaching tank at a solid-liquid ratio of 1 g: 5 mL, leaching at 80° C. for 3 h, adding caustic soda flakes to adjust the pH to 4, filtering to obtain a filter residue, and sending the filtrate to a sewage treatment workshop;

[0042] (3) mixing the filter residue, coke and potassium carbonate in a mass ratio of 10:1:1 and adding the mixture into a medium frequency furnace, smelting the mixture at 1200° C. for 6 h, removing the surface scum and cooling the mixture to obtain an indium-containing alloy;

[0043] (4) adding an indium-containing alloy, ammonium chloride, and glycerol into a smelting furnace in a mass ratio of 100:1:5, and smelting at 400° C. for 2 h to obtain an indium ingot;

[0044] (5) The indium ingot is placed in a graphite crucible, which is then placed in a vacuum distillation furnace. Vacuum distillation is performed at a vacuum degree of 1 Pa, a distillation temperature of 1200° C., and a time of 6 h to obtain refined indium.

[0045] Example 2

[0046] A method for recovering indium from an indium-containing material comprises the following steps:

[0047] (1) crushing the indium-containing material into 50 meshes using a crusher to obtain indium-containing material powder;

[0048] The indium-containing material mainly includes the following components: In 8.62%, Sn 35.83%, Bi 15.21%, Zn 1.42%, Fe 2.19%, Pb 0.85%, and Cu 1.58%.

[0049] (2) adding indium-containing material powder and sulfuric acid solution into a leaching tank at a solid-liquid ratio of 1 g: 5 mL, leaching at 80° C. for 3 h, adding caustic soda flakes to adjust the pH to 4, filtering to obtain a filter residue, and sending the filtrate to a sewage treatment workshop;

[0050] (3) mixing the filter residue, coke and potassium carbonate in a mass ratio of 20:3:5 and adding the mixture into a medium frequency furnace, smelting the mixture at 1200° C. for 6 h, removing the surface scum and cooling the mixture to obtain an indium-containing alloy;

[0051] (4) adding an indium-containing alloy, ammonium chloride, and glycerol into a smelting furnace in a mass ratio of 100:1:5, and smelting at 400° C. for 2 h to obtain an indium ingot;

[0052] (5) The indium ingot is placed in a graphite crucible, which is then placed in a vacuum distillation furnace. Vacuum distillation is performed at a vacuum degree of 1 Pa, a distillation temperature of 1200° C., and a time of 6 h to obtain refined indium.

[0053] Example 3

[0054] A method for recovering indium from an indium-containing material comprises the following steps:

[0055] (1) crushing the indium-containing material into 50 meshes using a crusher to obtain indium-containing material powder;

[0056] The indium-containing material mainly includes the following components: In 8.62%, Sn 35.83%, Bi 15.21%, Zn 1.42%, Fe 2.19%, Pb 0.85%, and Cu 1.58%.

[0057] (2) adding indium-containing material powder and sulfuric acid solution into a leaching tank at a solid-liquid ratio of 1 g: 5 mL, leaching at 80° C. for 3 h, adding caustic soda flakes to adjust the pH to 4, filtering to obtain a filter residue, and sending the filtrate to a sewage treatment workshop;

[0058] (3) mixing the filter residue, coke and potassium carbonate in a mass ratio of 10:1:1 and adding the mixture into a medium frequency furnace, smelting the mixture at 800° C. for 8 h, removing the surface scum and cooling the mixture to obtain an indium-containing alloy;

[0059] (4) adding an indium-containing alloy, ammonium chloride, and glycerol into a smelting furnace in a mass ratio of 100:1:5, and smelting at 400° C. for 2 h to obtain an indium ingot;

[0060] (5) The indium ingot is placed in a graphite crucible, which is then placed in a vacuum distillation furnace. Vacuum distillation is performed at a vacuum degree of 1 Pa, a distillation temperature of 1200° C., and a time of 6 h to obtain refined indium.

[0061] Example 4

[0062] A method for recovering indium from an indium-containing material comprises the following steps:

[0063] (1) crushing the indium-containing material into 50 meshes using a crusher to obtain indium-containing material powder;

[0064] The indium-containing material mainly includes the following components: In 8.62%, Sn 35.83%, Bi 15.21%, Zn 1.42%, Fe 2.19%, Pb 0.85%, and Cu 1.58%.

[0065] (2) adding indium-containing material powder and sulfuric acid solution into a leaching tank at a solid-liquid ratio of 1 g: 5 mL, leaching at 80° C. for 3 h, adding caustic soda flakes to adjust the pH to 4, filtering to obtain a filter residue, and sending the filtrate to a sewage treatment workshop;

[0066] (3) mixing the filter residue, coke and potassium carbonate in a mass ratio of 10:1:1 and adding the mixture into a medium frequency furnace, smelting the mixture at 1200° C. for 6 h, removing the surface scum and cooling the mixture to obtain an indium-containing alloy;

[0067] (4) adding an indium-containing alloy, ammonium chloride, and glycerol into a smelting furnace in a mass ratio of 150:5:10, and smelting at 400° C. for 2 h to obtain an indium ingot;

[0068] (5) The indium ingot is placed in a graphite crucible, which is then placed in a vacuum distillation furnace. Vacuum distillation is performed at a vacuum degree of 1 Pa, a distillation temperature of 1200° C., and a time of 6 h to obtain refined indium.

[0069] Example 5

[0070] A method for recovering indium from an indium-containing material comprises the following steps:

[0071] (1) crushing the indium-containing material into 50 meshes using a crusher to obtain indium-containing material powder;

[0072] The indium-containing material mainly includes the following components: In 8.62%, Sn 35.83%, Bi 15.21%, Zn 1.42%, Fe 2.19%, Pb 0.85%, and Cu 1.58%.

[0073] (2) adding indium-containing material powder and sulfuric acid solution into a leaching tank at a solid-liquid ratio of 1 g: 5 mL, leaching at 80° C. for 3 h, adding caustic soda flakes to adjust the pH to 4, filtering to obtain a filter residue, and sending the filtrate to a sewage treatment workshop;

[0074] (3) mixing the filter residue, coke and potassium carbonate in a mass ratio of 10:1:1 and adding the mixture into a medium frequency furnace, smelting the mixture at 1200° C. for 6 h, removing the surface scum and cooling the mixture to obtain an indium-containing alloy;

[0075] (4) adding an indium-containing alloy, ammonium chloride, and glycerol into a smelting furnace in a mass ratio of 10:1:1, and smelting at 300° C. for 3 h to obtain an indium ingot;

[0076] (5) The indium ingot is placed in a graphite crucible, which is then placed in a vacuum distillation furnace. Vacuum distillation is performed at a vacuum degree of 1 Pa, a distillation temperature of 1200° C., and a time of 6 h to obtain refined indium.

[0077] Example 6

[0078] A method for recovering indium from an indium-containing material comprises the following steps:

[0079] (1) crushing the indium-containing material into 50 meshes using a crusher to obtain indium-containing material powder;

[0080] The indium-containing material mainly includes the following components: In 8.62%, Sn 35.83%, Bi 15.21%, Zn 1.42%, Fe 2.19%, Pb 0.85%, and Cu 1.58%.

[0081] (2) adding indium-containing material powder and sulfuric acid solution into a leaching tank at a solid-liquid ratio of 1 g: 5 mL, leaching at 80° C. for 3 h, adding caustic soda flakes to adjust the pH to 4, filtering to obtain a filter residue, and sending the filtrate to a sewage treatment workshop;

[0082] (3) mixing the filter residue, coke and potassium carbonate in a mass ratio of 10:1:1 and adding the mixture into a medium frequency furnace, smelting the mixture at 1200° C. for 6 h, removing the surface scum and cooling the mixture to obtain an indium-containing alloy;

[0083] (4) adding an indium-containing alloy, ammonium chloride, and glycerol into a smelting furnace in a mass ratio of 100:1:5, and smelting at 400° C. for 2 h to obtain an indium ingot;

[0084] (5) The indium ingot is placed in a graphite crucible, which is then placed in a vacuum distillation furnace. Vacuum distillation is performed at a vacuum degree of 1 Pa, a distillation temperature of 1000° C., and a time of 8 h to obtain refined indium.

[0085] Comparative Example 1

[0086] A method for recovering indium from an indium-containing material comprises the following steps:

[0087] (1) crushing the indium-containing material into 50 meshes using a crusher to obtain indium-containing material powder;

[0088] The indium-containing material mainly includes the following components: In 8.62%, Sn 35.83%, Bi 15.21%, Zn 1.42%, Fe 2.19%, Pb 0.85%, and Cu 1.58%.

[0089] (2) adding indium-containing material powder and sulfuric acid solution into a leaching tank at a solid-liquid ratio of 1 g: 5 mL, leaching at 80° C. for 3 h, adding caustic soda flakes to adjust the pH to 4, filtering to obtain a filter residue, and sending the filtrate to a sewage treatment workshop;

[0090] (3) adding the filtered residue into a medium frequency furnace, smelting at 1200° C. for 6 h, removing the surface scum, cooling, and obtaining an indium-containing alloy;

[0091] (4) adding an indium-containing alloy, ammonium chloride, and glycerol into a smelting furnace in a mass ratio of 100:1:5, and smelting at 400° C. for 2 h to obtain an indium ingot;

[0092] (5) The indium ingot is placed in a graphite crucible, which is then placed in a vacuum distillation furnace. Vacuum distillation is performed at a vacuum degree of 1 Pa, a distillation temperature of 1200° C., and a time of 6 h to obtain refined indium.

[0093] Comparative Example 2

[0094] A method for recovering indium from an indium-containing material comprises the following steps:

[0095] (1) crushing the indium-containing material into 50 meshes using a crusher to obtain indium-containing material powder;

[0096] The indium-containing material mainly includes the following components: In 8.62%, Sn 35.83%, Bi 15.21%, Zn 1.42%, Fe 2.19%, Pb 0.85%, and Cu 1.58%.

[0097] (2) adding indium-containing material powder and sulfuric acid solution into a leaching tank at a solid-liquid ratio of 1 g: 5 mL, leaching at 80° C. for 3 h, adding caustic soda flakes to adjust the pH to 4, filtering to obtain a filter residue, and sending the filtrate to a sewage treatment workshop;

[0098] (3) mixing the filter residue, coke and potassium carbonate in a mass ratio of 10:0.5:8 and adding the mixture into a medium frequency furnace, smelting the mixture at 1200° C. for 6 h, removing the surface scum and cooling the mixture to obtain an indium-containing alloy;

[0099] (4) adding an indium-containing alloy, ammonium chloride, and glycerol into a smelting furnace in a mass ratio of 100:1:5, and smelting at 400° C. for 2 h to obtain an indium ingot;

[0100] (5) The indium ingot is placed in a graphite crucible, which is then placed in a vacuum distillation furnace. Vacuum distillation is performed at a vacuum degree of 1 Pa, a distillation temperature of 1200° C., and a time of 6 h to obtain refined indium.

[0101] Comparative Example 3

[0102] A method for recovering indium from an indium-containing material comprises the following steps:

[0103] (1) crushing the indium-containing material into 50 meshes using a crusher to obtain indium-containing material powder;

[0104] The indium-containing material mainly includes the following components: In 8.62%, Sn 35.83%, Bi 15.21%, Zn 1.42%, Fe 2.19%, Pb 0.85%, and Cu 1.58%.

[0105] (2) adding indium-containing material powder and sulfuric acid solution into a leaching tank at a solid-liquid ratio of 1 g: 5 mL, leaching at 80° C. for 3 h, adding caustic soda flakes to adjust the pH to 4, filtering to obtain a filter residue, and sending the filtrate to a sewage treatment workshop;

[0106] (3) mixing the filter residue, coke and potassium carbonate in a mass ratio of 10:5:0.5 and adding the mixture into a medium frequency furnace, smelting the mixture at 1200° C. for 6 h, removing the surface scum and cooling the mixture to obtain an indium-containing alloy;

[0107] (4) adding an indium-containing alloy, ammonium chloride, and glycerol into a smelting furnace in a mass ratio of 100:1:5, and smelting at 400° C. for 2 h to obtain an indium ingot;

[0108] (5) The indium ingot is placed in a graphite crucible, which is then placed in a vacuum distillation furnace. Vacuum distillation is performed at a vacuum degree of 1 Pa, a distillation temperature of 1200° C., and a time of 6 h to obtain refined indium.

[0109] Comparative Example 4

[0110] A method for recovering indium from an indium-containing material comprises the following steps:

[0111] (1) crushing the indium-containing material into 50 meshes using a crusher to obtain indium-containing material powder;

[0112] The indium-containing material mainly includes the following components: In 8.62%, Sn 35.83%, Bi 15.21%, Zn 1.42%, Fe 2.19%, Pb 0.85%, and Cu 1.58%.

[0113] (2) adding indium-containing material powder and sulfuric acid solution into a leaching tank at a solid-liquid ratio of 1 g: 5 mL, leaching at 80° C. for 3 h, adding caustic soda flakes to adjust the pH to 4, filtering to obtain a filter residue, and sending the filtrate to a sewage treatment workshop;

[0114] (3) mixing the filter residue, coke and potassium carbonate in a mass ratio of 10:1:1 and adding the mixture into a medium frequency furnace, smelting the mixture at 1200° C. for 6 h, removing the surface scum and cooling the mixture to obtain an indium-containing alloy;

[0115] (4) The indium-containing alloy is placed in a graphite crucible, placed in a vacuum distillation furnace, and vacuum distilled at a vacuum degree of 1 Pa, a distillation temperature of 1200° C., and a time of 6 hours to obtain refined indium.

[0116] Comparative Example 5

[0117] A method for recovering indium from an indium-containing material comprises the following steps:

[0118] (1) crushing the indium-containing material into 50 meshes using a crusher to obtain indium-containing material powder;

[0119] The indium-containing material mainly includes the following components: In 8.62%, Sn 35.83%, Bi 15.21%, Zn 1.42%, Fe 2.19%, Pb 0.85%, and Cu 1.58%.

[0120] (2) adding indium-containing material powder and sulfuric acid solution into a leaching tank at a solid-liquid ratio of 1 g: 5 mL, leaching at 80° C. for 3 h, adding caustic soda flakes to adjust the pH to 4, filtering to obtain a filter residue, and sending the filtrate to a sewage treatment workshop;

[0121] (3) mixing the filter residue, coke and potassium carbonate in a mass ratio of 10:1:1 and adding the mixture into a medium frequency furnace, smelting the mixture at 1200° C. for 6 h, removing the surface scum and cooling the mixture to obtain an indium-containing alloy;

[0122] (4) adding an indium-containing alloy, ammonium chloride, and glycerol into a smelting furnace in a mass ratio of 100:0.5:20, and smelting at 400° C. for 2 h to obtain an indium ingot;

[0123] (5) The indium ingot is placed in a graphite crucible, which is then placed in a vacuum distillation furnace. Vacuum distillation is performed at a vacuum degree of 1 Pa, a distillation temperature of 1200° C., and a time of 6 h to obtain refined indium.

[0124] Comparative Example 6

[0125] A method for recovering indium from an indium-containing material comprises the following steps:

[0126] (1) crushing the indium-containing material into 50 meshes using a crusher to obtain indium-containing material powder;

[0127] The indium-containing material mainly includes the following components: In 8.62%, Sn 35.83%, Bi 15.21%, Zn 1.42%, Fe 2.19%, Pb 0.85%, and Cu 1.58%.

[0128] (2) adding indium-containing material powder and sulfuric acid solution into a leaching tank at a solid-liquid ratio of 1 g: 5 mL, leaching at 80° C. for 3 h, adding caustic soda flakes to adjust the pH to 4, filtering to obtain a filter residue, and sending the filtrate to a sewage treatment workshop;

[0129] (3) mixing the filter residue, coke and potassium carbonate in a mass ratio of 10:1:1 and adding the mixture into a medium frequency furnace, smelting the mixture at 1200° C. for 6 h, removing the surface scum and cooling the mixture to obtain an indium-containing alloy;

[0130] (4) adding an indium-containing alloy, ammonium chloride, and glycerol into a smelting furnace in a mass ratio of 100:10:1, and smelting at 400° C. for 2 h to obtain an indium ingot;

[0131] (5) The indium ingot is placed in a graphite crucible, which is then placed in a vacuum distillation furnace. Vacuum distillation is performed at a vacuum degree of 1 Pa, a distillation temperature of 1200° C., and a time of 6 h to obtain refined indium.

[0132] Comparative Example 7

[0133] A method for recovering indium from an indium-containing material comprises the following steps:

[0134] (1) crushing the indium-containing material into 50 meshes using a crusher to obtain indium-containing material powder;

[0135] The indium-containing material mainly includes the following components: In 8.62%, Sn 35.83%, Bi 15.21%, Zn 1.42%, Fe 2.19%, Pb 0.85%, and Cu 1.58%.

[0136] (2) adding indium-containing material powder and sulfuric acid solution into a leaching tank at a solid-liquid ratio of 1 g: 5 mL, leaching at 80° C. for 3 h, adding caustic soda flakes to adjust the pH to 4, filtering to obtain a filter residue, and sending the filtrate to a sewage treatment workshop;

[0137] (3) mixing the filter residue, coke and potassium carbonate in a mass ratio of 10:1:1 and adding the mixture into a medium frequency furnace, smelting the mixture at 1200° C. for 6 h, removing the surface scum and cooling the mixture to obtain an indium-containing alloy;

[0138] (4) adding an indium-containing alloy, ammonium chloride, and glycerol into a smelting furnace in a mass ratio of 100:1:5, and smelting at 200° C. for 2 h to obtain an indium ingot;

[0139] (5) The indium ingot is placed in a graphite crucible, which is then placed in a vacuum distillation furnace. Vacuum distillation is performed at a vacuum degree of 1 Pa, a distillation temperature of 1200° C., and a time of 6 h to obtain refined indium.

[0140] Comparative Example 8

[0141] A method for recovering indium from an indium-containing material comprises the following steps:

[0142] (1) crushing the indium-containing material into 50 meshes using a crusher to obtain indium-containing material powder;

[0143] The indium-containing material mainly includes the following components: In 8.62%, Sn 35.83%, Bi 15.21%, Zn 1.42%, Fe 2.19%, Pb 0.85%, and Cu 1.58%.

[0144] (2) adding indium-containing material powder and sulfuric acid solution into a leaching tank at a solid-liquid ratio of 1 g: 5 mL, leaching at 80° C. for 3 h, adding caustic soda flakes to adjust the pH to 4, filtering to obtain a filter residue, and sending the filtrate to a sewage treatment workshop;

[0145] (3) mixing the filter residue, coke and potassium carbonate in a mass ratio of 10:1:1 and adding the mixture into a medium frequency furnace, smelting the mixture at 1200° C. for 6 h, removing the surface scum and cooling the mixture to obtain an indium-containing alloy;

[0146] (4) adding an indium-containing alloy, ammonium chloride, and glycerol into a smelting furnace in a mass ratio of 100:1:5, and smelting at 500° C. for 2 h to obtain an indium ingot;

[0147] (5) The indium ingot is placed in a graphite crucible, which is then placed in a vacuum distillation furnace. Vacuum distillation is performed at a vacuum degree of 1 Pa, a distillation temperature of 1200° C., and a time of 6 h to obtain refined indium.

[0148] Test Case

[0149] The purity and recovery rate of the refined indium in the embodiment and the comparative example are shown in Table 1.

[0150] Table 1

[0151] Refined Indium Purity Recovery rate / % Example 1 99.99 99.56 Example 2 99.99 98.12 Example 3 99.85 97.23 Example 4 99.53 96.53 Example 5 99.64 97.63 Example 6 99.15 98.28 Comparative Example 1 80.15 90.32 Comparative Example 2 92.99 98.20 Comparative Example 3 99.99 93.15 Comparative Example 4 65.18 72.15 Comparative Example 5 96.55 95.25 Comparative Example 6 97.95 95.58 Comparative Example 7 90.25 92.18 Comparative Example 8 99.99 86.72

[0152] The invention wet-leaches indium-containing material powder with sulfuric acid solution, uses caustic soda to adjust the pH to 3-5, can selectively separate part of the impurity metal and indium, performs preliminary treatment, effectively enriches indium, and then performs high-temperature smelting reduction in the presence of a reducing agent and a slag-forming agent to reduce the metal oxide to metal, and simultaneously removes part of the sulfur element, and then performs halogenation refining, utilizes the affinity of part of the metal impurities to the halogenated element to be greater than the affinity of the indium metal, to remove impurities in a targeted manner, and utilizes the different saturated vapor pressures of the indium metal and other metals through vacuum distillation to purify the indium metal. The whole process is simple to operate and has a high recovery rate of the indium metal.

[0153] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the essence and scope of the technical solution of the present invention.

Claims

1. A method for recovering indium from an indium-containing material, characterized in that: The following steps are involved: (1) crushing the indium-containing material to obtain indium-containing material powder; (2) leaching the indium-containing material powder with a sulfuric acid solution, adding caustic soda to adjust the pH to 3-5, filtering, and obtaining a filter residue; (3) uniformly mixing the filter residue, the reducing agent, and the slag-forming agent, and smelting the mixture to obtain an indium-containing alloy; (4) adding an indium-containing alloy, a halogenating agent, and a softening agent into a smelting furnace, smelting, and obtaining an indium ingot; (5) Vacuum distill the indium ingot to obtain refined indium.

2. The method for recovering indium from an indium-containing material according to claim 1, characterized in that: The solid-to-liquid ratio of the indium-containing material powder to the sulfuric acid solution is 1 g: (4-6) mL.

3. The method for recovering indium from an indium-containing material according to claim 1, characterized in that: The concentration of the sulfuric acid solution is 5-8wt%; The leaching temperature is 75-85° C. and the leaching time is 2-5 hours.

4. The method for recovering indium from an indium-containing material according to claim 1, characterized in that: The mass ratio of the filter residue, the reducing agent and the slag-forming agent is (10-20): (1-3): (1-5).

5. The method for recovering indium from an indium-containing material according to claim 1, characterized in that: The reducing agent includes at least one of anthracite, coke, and flour; The slag-forming agent includes at least one of sodium chloride, potassium carbonate, sodium carbonate, quartz sand and borax.

6. The method for recovering indium from an indium-containing material according to claim 1, characterized in that: The smelting temperature in step (3) is 800-1200° C. and the smelting time is 6-8 hours.

7. The method for recovering indium from an indium-containing material according to claim 1, characterized in that: The mass ratio of the indium-containing alloy, the halogenating agent and the softening agent is (100-150): (1-5): (5-10).

8. The method for recovering indium from an indium-containing material according to claim 1, characterized in that: The softener includes at least one of glycerol, ethylene glycol, and sorbitol; The halogenating agent includes at least one of ammonium chloride, zinc chloride and chlorine.

9. The method for recovering indium from an indium-containing material according to claim 1, characterized in that: The smelting temperature in step (4) is 300-400° C. and the smelting time is 1-4 hours.

10. The method for recovering indium from an indium-containing material according to claim 1, characterized in that: The vacuum distillation temperature is 1000-1200° C. and the time is 6-10 hours.