Method for recovering indium from indium-containing material

Abstract

The invention discloses a method for recovering indium from an indium-containing material, which belongs to the technical field of resource recycling and reutilization, and comprises the following steps: performing sulfating roasting on the high-lead, high-tin, high-zinc and high-sulfur indium-containing material, effectively removing S and chlorine, converting metal into sulfate which is easy to dissolve in water, facilitating subsequent leaching, volatilizing S at the same time, and recovering indium from the indium-containing material. The metal leaching rate is effectively improved; secondary leaching is adopted, the leaching effect can be effectively improved, leaching of lead is promoted, hydrogen sulfide is introduced to convert Sn into precipitates to be removed when indium is in an ionic state, after the pH is adjusted through sodium carbonate, a replacement reaction is conducted, indium metal is effectively replaced, and finally heat treatment is conducted to obtain crude indium.

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 is a rare associated metal found in zinc, lead, copper or tin ores in nature. It can form compounds with excellent physical and chemical properties with a variety of metal elements and is often used in the fields of microelectronic materials, optics, chemical industry, aviation and military industry.

[0003] Currently, there are few indium metal resources that can be directly mined in the earth's crust. Therefore, recovering indium metal from secondary indium-containing resources is the mainstream trend of future development. However, due to the complex composition of secondary indium-containing resources, especially for materials with high impurity elements such as lead, tin, and sulfur, it is difficult to effectively remove impurity elements such as lead, tin, and sulfur.

[0004] In view of this, this application is filed. Summary of the invention

[0005] 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 from indium-containing materials with high lead, high tin, high zinc and high sulfur content to obtain crude indium, and effectively remove lead, tin, zinc, sulfur and other impurity elements, and has broad application prospects.

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

[0007] A method for recovering indium from an indium-containing material comprises the following steps:

[0008] (1) grinding an indium-containing material to obtain an indium-containing powder;

[0009] (2) mixing the indium-containing powder and the sulfuric acid solution uniformly, and roasting to obtain roasted slag;

[0010] (3) leaching the roasted slag with a first leaching solution and then leaching it with a second leaching solution to obtain a leaching solution;

[0011] (4) adding sulfuric acid solution to the leaching solution, introducing hydrogen sulfide gas to react, and filtering to obtain a filtrate;

[0012] (5) adjusting the pH of the filtrate to 1.5-2.5 with sodium carbonate, adding a zinc plate to carry out a replacement reaction, and obtaining sponge indium;

[0013] (6) Covering the surface of sponge indium with caustic soda and subjecting it to heat treatment to obtain crude indium.

[0014] The present invention creatively subjects the indium-containing material with high lead, high tin, high zinc and high sulfur to sulfurization roasting first, effectively removes S and chlorine, converts the metal into a sulfate that is easily soluble in water, facilitates subsequent leaching, and volatilizes S, effectively improving the metal leaching rate; adopts secondary leaching, which can effectively improve the leaching effect and promote the leaching of lead; introduces hydrogen sulfide when indium is still in an ionic state, converts Sn into a precipitate for removal; after adjusting the pH with sodium carbonate, a replacement reaction is carried out to effectively replace the indium metal; and finally, crude indium is obtained through heat treatment.

[0015] The method disclosed in the present invention can effectively recover indium from indium-containing materials with high lead, high tin, high zinc and high sulfur content to obtain crude indium, and effectively remove lead, tin, zinc, sulfur and other impurity elements, thus having broad application prospects.

[0016] As a preferred embodiment of the present invention, the main components of the indium-containing material are: 0.8-2% In, 8-12% Pb, 6-10% Sn, 25-30% Zn, 4-6% Cu, 28-35% S, and 1-2% Cl.

[0017] As a preferred embodiment of the present invention, the mass mixing ratio of the indium-containing powder and 95-98wt% concentrated sulfuric acid is (2-4):1.

[0018] As a preferred embodiment of the present invention, the concentration of the sulfuric acid solution in step (2) is 95-98 wt%.

[0019] As a preferred embodiment of the present invention, the calcination temperature is 350-450° C., and the calcination time is 2-5 hours.

[0020] As a preferred embodiment of the present invention, the heat treatment temperature is 250-350° C., and the heat treatment time is 2-5 hours.

[0021] As a preferred embodiment of the present invention, the first acid solution comprises an oxidant and a first acid solution, and the mass ratio of the oxidant to the first acid solution is 1:(3-5);

[0022] The oxidant includes at least one of sodium hypochlorite and potassium permanganate;

[0023] The first acid solution includes at least one of a 2-4 mol / L hydrochloric acid solution, a 2-4 mol / L acetic acid solution, a 2-4 mol / L oxalic acid solution, and a 2-4 mol / L nitric acid solution;

[0024] The second leaching solution includes at least one of a 4-6 mol / L nitric acid solution and a 4-6 mol / L sulfuric acid solution.

[0025] As a preferred embodiment of the present invention, the solid-liquid ratio of the calcined slag, the first leaching solution and the second leaching solution is 1g: (4-6)mL: (2-3)mL.

[0026] As a preferred embodiment of the present invention, the leaching temperature is 50-60°C and the leaching time is 1-4 hours.

[0027] As a preferred embodiment of the present invention, the solid-to-liquid ratio of the calcined slag to the acid solution is 1 g: (4-6) mL.

[0028] As a preferred embodiment of the present invention, the concentration of the sulfuric acid solution in step (4) is 10 to 20 wt%.

[0029] As a preferred embodiment of the present invention, the volume ratio of the leaching solution to the sulfuric acid solution is (4-6):1.

[0030] As a preferred embodiment of the present invention, the amount of hydrogen sulfide gas introduced is 1 to 2 L / min.

[0031] As a preferred embodiment of the present invention, the reaction temperature in step (4) is 70 to 90° C. and the reaction time is 4 to 6 hours.

[0032] As a preferred embodiment of the present invention, the mass ratio of the caustic soda to the sponge indium is (0.4-0.5):1.

[0033] The beneficial effects of the present invention are as follows: the present invention firstly subjectes the indium-containing material with high lead, high tin, high zinc and high sulfur to sulfurization roasting, effectively removes S and chlorine, converts the metal into a sulfate that is easily soluble in water, facilitates subsequent leaching, and volatilizes S, effectively improving the metal leaching rate; adopts secondary leaching, can effectively improve the leaching effect, promote the leaching of lead, introduces hydrogen sulfide when indium is still in an ionic state, converts Sn into a precipitate for removal, adjusts the pH with sodium carbonate, performs a replacement reaction, effectively replaces the indium metal, and finally obtains crude indium through heat treatment. DETAILED DESCRIPTION

[0034] 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.

[0035] 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.

[0036] 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.

[0037] In the present application, there is no particular limitation on the specific dispersion and stirring treatment methods.

[0038] 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.

[0039] The following examples are provided to facilitate understanding of the present invention. These examples are not provided to limit the scope of the claims.

[0040] Example 1

[0041] A method for recovering indium from an indium-containing material comprises the following steps:

[0042] (1) Spread the indium-containing material on a stainless steel tray, put it into a drying oven, dry it, take it out, and grind it to 100 mesh to obtain indium-containing powder;

[0043] The main components of the indium-containing material are: In 1.32%, Pb 10.21%, Sn 8.93%, Zn 27.95%, Cu 5.2%, S 31.58%, Cl 1.3%, and other elements 14.83%.

[0044] (2) mixing the indium-containing powder and 98 wt % concentrated sulfuric acid in a mass ratio of 1:0.7, placing the mixture in a corundum crucible and placing the mixture in a muffle furnace, and calcining the mixture at 400° C. for 3 h to obtain calcined slag;

[0045] (3) mixing sodium hypochlorite and 4 mol / L hydrochloric acid solution in a mass ratio of 1:4 to obtain a first leachate;

[0046] The roasted slag was mixed evenly with the first leaching solution in a reaction kettle, leached at 55°C for 1 hour, then leached for 1 hour by adding 6 mol / L sulfuric acid solution, and filtered to obtain a leaching solution;

[0047] The solid-liquid ratio of the roasted slag, the first leaching solution and the sulfuric acid solution is 1g:4mL:2mL.

[0048] (4) adding 15 wt % sulfuric acid solution to the leaching solution, introducing hydrogen sulfide gas at a flow rate of 2 L / min, reacting at 80° C. for 5 h, and filtering by pressure to obtain a filtrate;

[0049] The volume ratio of the leaching solution to the sulfuric acid solution is 5:1.

[0050] (5) adjusting the pH of the filtrate to 2 with sodium carbonate, adding a 4N purity zinc plate to carry out a replacement reaction for 48 hours to obtain sponge indium;

[0051] (6) Press the sponge indium into a cake, cover the surface of the sponge indium with caustic soda, put it into an induction medium frequency furnace, heat treat it at 400° C. for 4 hours, remove the upper scum, and obtain 99% crude indium.

[0052] The mass ratio of the caustic soda to sponge indium is 0.5:1.

[0053] Example 2

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

[0055] (1) Spread the indium-containing material on a stainless steel tray, put it into a drying oven, dry it, take it out, and grind it to 100 mesh to obtain indium-containing powder;

[0056] The main components of the indium-containing material are: In 1.32%, Pb 10.21%, Sn 8.93%, Zn 27.95%, Cu 5.2%, S 31.58%, Cl 1.3%, and other elements 14.83%.

[0057] (2) mixing the indium-containing powder and 98 wt % sulfuric acid solution in a solid-liquid ratio of 1 g:2 mL, placing the mixture in a corundum crucible and placing the mixture in a muffle furnace, and calcining the mixture at 400° C. for 3 h to obtain calcined slag;

[0058] (3) mixing sodium hypochlorite and 4 mol / L hydrochloric acid solution in a mass ratio of 1:4 to obtain a first leachate;

[0059] The roasted slag was mixed evenly with the first leaching solution in a reaction kettle, leached at 55°C for 1 hour, then leached for 1 hour by adding 6 mol / L sulfuric acid solution, and filtered to obtain a leaching solution;

[0060] The solid-liquid ratio of the roasted slag, the first leaching solution and the sulfuric acid solution is 1g:5mL:2mL.

[0061] (4) adding 15 wt % sulfuric acid solution to the leaching solution, introducing hydrogen sulfide gas at a flow rate of 2 L / min, reacting at 80° C. for 5 h, and filtering by pressure to obtain a filtrate;

[0062] The volume ratio of the leaching solution to the sulfuric acid solution is 5:1.

[0063] (5) adjusting the pH of the filtrate to 2 with sodium carbonate, adding a 4N purity zinc plate to carry out a replacement reaction for 48 hours to obtain sponge indium;

[0064] (6) Press the sponge indium into a cake, cover the surface of the sponge indium with caustic soda, put it into an induction medium frequency furnace, heat treat it at 400° C. for 4 h, remove the upper scum, and obtain crude indium.

[0065] The mass ratio of the caustic soda to sponge indium is 0.5:1.

[0066] Example 3

[0067] A method for recovering indium from an indium-containing material comprises the following steps:

[0068] (1) Spread the indium-containing material on a stainless steel tray, put it into a drying oven, dry it, take it out, and grind it to 100 mesh to obtain indium-containing powder;

[0069] The main components of the indium-containing material are: In 1.32%, Pb 10.21%, Sn 8.93%, Zn 27.95%, Cu 5.2%, S 31.58%, Cl 1.3%, and other elements 14.83%.

[0070] (2) mixing the indium-containing powder and 98 wt % sulfuric acid solution in a solid-liquid ratio of 1 g:2 mL, placing the mixture in a corundum crucible and placing the mixture in a muffle furnace, and calcining the mixture at 400° C. for 3 h to obtain calcined slag;

[0071] (3) mixing potassium permanganate and 4 mol / L nitric acid solution in a mass ratio of 1:4 to obtain a first leachate;

[0072] The roasted slag was mixed evenly with the first leaching solution in a reaction kettle, leached at 55°C for 1 hour, then leached for 1 hour by adding 6 mol / L sulfuric acid solution, and filtered to obtain a leaching solution;

[0073] The solid-liquid ratio of the roasted slag, the first leaching solution and the sulfuric acid solution is 1g:5mL:2mL.

[0074] (4) adding 15 wt % sulfuric acid solution to the leaching solution, introducing hydrogen sulfide gas at a flow rate of 2 L / min, reacting at 80° C. for 5 h, and filtering by pressure to obtain a filtrate;

[0075] The volume ratio of the leaching solution to the sulfuric acid solution is 5:1.

[0076] (5) adjusting the pH of the filtrate to 2 with sodium carbonate, adding a 4N purity zinc plate to carry out a replacement reaction for 48 hours to obtain sponge indium;

[0077] (6) Press the sponge indium into a cake, cover the surface of the sponge indium with caustic soda, put it into an induction medium frequency furnace, heat treat it at 400° C. for 4 h, remove the upper scum, and obtain crude indium.

[0078] The mass ratio of the caustic soda to sponge indium is 0.5:1.

[0079] Example 4

[0080] A method for recovering indium from an indium-containing material comprises the following steps:

[0081] (1) Spread the indium-containing material on a stainless steel tray, put it into a drying oven, dry it, take it out, and grind it to 100 mesh to obtain indium-containing powder;

[0082] The main components of the indium-containing material are: In 1.32%, Pb 10.21%, Sn 8.93%, Zn 27.95%, Cu 5.2%, S 31.58%, Cl 1.3%, and other elements 14.83%.

[0083] (2) mixing the indium-containing powder and 98 wt % sulfuric acid solution in a solid-liquid ratio of 1 g:2 mL, placing the mixture in a corundum crucible and placing the mixture in a muffle furnace, and calcining the mixture at 400° C. for 3 h to obtain calcined slag;

[0084] (3) mixing sodium hypochlorite and 4 mol / L hydrochloric acid solution in a mass ratio of 1:4 to obtain a first leachate;

[0085] The roasted slag was mixed evenly with the first leaching solution in a reaction kettle, leached at 55°C for 1 hour, then leached for 1 hour by adding 6 mol / L sulfuric acid solution, and filtered to obtain a leaching solution;

[0086] The solid-liquid ratio of the roasted slag, the first leaching solution and the sulfuric acid solution is 1g:4mL:2mL.

[0087] (4) adding 15 wt % sulfuric acid solution to the leaching solution, introducing hydrogen sulfide gas at a flow rate of 2 L / min, reacting at 80° C. for 5 h, and filtering by pressure to obtain a filtrate;

[0088] The volume ratio of the leaching solution to the sulfuric acid solution is 5:1.

[0089] (5) The pH of the filtrate was adjusted to 1.5 with sodium carbonate, and a 4N purity zinc plate was added to carry out a replacement reaction for 48 hours to obtain sponge indium;

[0090] (6) Press the sponge indium into a cake, cover the surface of the sponge indium with caustic soda, put it into an induction medium frequency furnace, heat treat it at 400° C. for 4 h, remove the upper scum, and obtain crude indium.

[0091] The mass ratio of the caustic soda to sponge indium is 0.5:1.

[0092] Example 5

[0093] A method for recovering indium from an indium-containing material comprises the following steps:

[0094] (1) Spread the indium-containing material on a stainless steel tray, put it into a drying oven, dry it, take it out, and grind it to 100 mesh to obtain indium-containing powder;

[0095] The main components of the indium-containing material are: In 1.32%, Pb 10.21%, Sn 8.93%, Zn 27.95%, Cu 5.2%, S 31.58%, Cl 1.3%, and other elements 14.83%.

[0096] (2) mixing the indium-containing powder and 98 wt % sulfuric acid solution in a solid-liquid ratio of 1 g:2 mL, placing the mixture in a corundum crucible and placing the mixture in a muffle furnace, and calcining the mixture at 400° C. for 3 h to obtain calcined slag;

[0097] (3) mixing sodium hypochlorite and 4 mol / L hydrochloric acid solution in a mass ratio of 1:4 to obtain a first leachate;

[0098] The roasted slag was mixed evenly with the first leaching solution in a reaction kettle, leached at 55°C for 1 hour, then leached for 1 hour by adding 6 mol / L sulfuric acid solution, and filtered to obtain a leaching solution;

[0099] The solid-liquid ratio of the roasted slag, the first leaching solution and the sulfuric acid solution is 1g:4mL:2mL.

[0100] (4) adding 15 wt % sulfuric acid solution to the leaching solution, introducing hydrogen sulfide gas at a flow rate of 2 L / min, reacting at 80° C. for 5 h, and filtering by pressure to obtain a filtrate;

[0101] The volume ratio of the leaching solution to the sulfuric acid solution is 5:1.

[0102] (5) The pH of the filtrate was adjusted to 2.5 with sodium carbonate, and a 4N purity zinc plate was added to carry out a replacement reaction for 48 hours to obtain sponge indium;

[0103] (6) Press the sponge indium into a cake, cover the surface of the sponge indium with caustic soda, put it into an induction medium frequency furnace, heat treat it at 400° C. for 4 h, remove the upper scum, and obtain crude indium.

[0104] The mass ratio of the caustic soda to sponge indium is 0.5:1.

[0105] Comparative Example 1

[0106] The difference between Comparative Example 1 and Example 1 is that only sulfuric acid solution is used for leaching, and the total leaching time is consistent with that of the example.

[0107] A method for recovering indium from an indium-containing material comprises the following steps:

[0108] (1) Spread the indium-containing material on a stainless steel tray, put it into a drying oven, dry it, take it out, and grind it to 100 mesh to obtain indium-containing powder;

[0109] The main components of the indium-containing material are: In 1.32%, Pb 10.21%, Sn 8.93%, Zn 27.95%, Cu 5.2%, S 31.58%, Cl 1.3%, and other elements 14.83%.

[0110] (2) mixing the indium-containing powder and 98 wt % sulfuric acid solution in a solid-liquid ratio of 1 g:2 mL, placing the mixture in a corundum crucible and placing the mixture in a muffle furnace, and calcining the mixture at 400° C. for 3 h to obtain calcined slag;

[0111] (3) leaching the roasted slag with sulfuric acid solution for 2 h, and filtering by pressure to obtain a leachate;

[0112] The solid-to-liquid ratio of the calcined slag to the sulfuric acid solution is 1 g:4 mL.

[0113] (4) adding 15 wt % sulfuric acid solution to the leaching solution, introducing hydrogen sulfide gas at a flow rate of 2 L / min, reacting at 80° C. for 5 h, and filtering by pressure to obtain a filtrate;

[0114] The volume ratio of the leaching solution to the sulfuric acid solution is 5:1.

[0115] (5) adjusting the pH of the filtrate to 2 with sodium carbonate, adding a 4N purity zinc plate to carry out a replacement reaction for 48 hours to obtain sponge indium;

[0116] (6) Press the sponge indium into a cake, cover the surface of the sponge indium with caustic soda, put it into an induction medium frequency furnace, heat treat it at 400° C. for 4 h, remove the upper scum, and obtain crude indium.

[0117] The mass ratio of the caustic soda to sponge indium is 0.5:1.

[0118] Comparative Example 2

[0119] A method for recovering indium from an indium-containing material comprises the following steps:

[0120] (1) Spread the indium-containing material on a stainless steel tray, put it into a drying oven, dry it, take it out, and grind it to 100 mesh to obtain indium-containing powder;

[0121] The main components of the indium-containing material are: In 1.32%, Pb 10.21%, Sn 8.93%, Zn 27.95%, Cu 5.2%, S 31.58%, Cl 1.3%, and other elements 14.83%.

[0122] (2) mixing the indium-containing powder and 98 wt % sulfuric acid solution in a solid-liquid ratio of 1 g:2 mL, placing the mixture in a corundum crucible and placing the mixture in a muffle furnace, and calcining the mixture at 400° C. for 3 h to obtain calcined slag;

[0123] (3) mixing sodium hypochlorite and 4 mol / L hydrochloric acid solution in a mass ratio of 1:4 to obtain a first leachate;

[0124] The roasted slag was mixed evenly with the first leaching solution in a reaction kettle, leached at 55°C for 1 hour, then leached for 1 hour by adding 6 mol / L sulfuric acid solution, and filtered to obtain a leaching solution;

[0125] The solid-liquid ratio of the roasted slag, the first leaching solution and the sulfuric acid solution is 1g:4mL:2mL.

[0126] (4) adding 15 wt % sulfuric acid solution to the leaching solution, reacting at 80° C. for 5 h, and filtering to obtain a filtrate;

[0127] The volume ratio of the leaching solution to the sulfuric acid solution is 5:1.

[0128] (5) adjusting the pH of the filtrate to 2 with sodium carbonate, adding a 4N purity zinc plate to carry out a replacement reaction for 48 hours to obtain sponge indium;

[0129] (6) Press the sponge indium into a cake, cover the surface of the sponge indium with caustic soda, put it into an induction medium frequency furnace, heat treat it at 400° C. for 4 h, remove the upper scum, and obtain crude indium.

[0130] The mass ratio of the caustic soda to sponge indium is 0.5:1.

[0131] Comparative Example 3

[0132] A method for recovering indium from an indium-containing material comprises the following steps:

[0133] (1) Spread the indium-containing material on a stainless steel tray, put it into a drying oven, dry it, take it out, and grind it to 100 mesh to obtain indium-containing powder;

[0134] The main components of the indium-containing material are: In 1.32%, Pb 10.21%, Sn 8.93%, Zn 27.95%, Cu 5.2%, S 31.58%, Cl 1.3%, and other elements 14.83%.

[0135] (2) placing the indium-containing powder in a corundum crucible into a muffle furnace and calcining at 400° C. for 3 h to obtain calcined slag;

[0136] (3) mixing sodium hypochlorite and 4 mol / L hydrochloric acid solution in a mass ratio of 1:4 to obtain a first leachate;

[0137] The roasted slag was mixed evenly with the first leaching solution in a reaction kettle, leached at 55°C for 1 hour, then leached for 1 hour by adding 6 mol / L sulfuric acid solution, and filtered to obtain a leaching solution;

[0138] The solid-liquid ratio of the roasted slag, the first leaching solution and the sulfuric acid solution is 1g:4mL:2mL.

[0139] (4) adding 15 wt % sulfuric acid solution to the leaching solution, introducing hydrogen sulfide gas at a flow rate of 2 L / min, reacting at 80° C. for 5 h, and filtering by pressure to obtain a filtrate;

[0140] The volume ratio of the leaching solution to the sulfuric acid solution is 5:1.

[0141] (5) adjusting the pH of the filtrate to 2 with sodium carbonate, adding a 4N purity zinc plate to carry out a replacement reaction for 48 hours to obtain sponge indium;

[0142] (6) Press the sponge indium into a cake, cover the surface of the sponge indium with caustic soda, put it into an induction medium frequency furnace, heat treat it at 400° C. for 4 h, remove the upper scum, and obtain crude indium.

[0143] The mass ratio of the caustic soda to sponge indium is 0.5:1.

[0144] Comparative Example 4

[0145] A method for recovering indium from an indium-containing material comprises the following steps:

[0146] (1) Spread the indium-containing material on a stainless steel tray, put it into a drying oven, dry it, take it out, and grind it to 100 mesh to obtain indium-containing powder;

[0147] The main components of the indium-containing material are: In 1.32%, Pb 10.21%, Sn 8.93%, Zn 27.95%, Cu 5.2%, S 31.58%, Cl 1.3%, and other elements 14.83%.

[0148] (2) mixing the indium-containing powder and 98 wt % sulfuric acid solution in a solid-liquid ratio of 1 g:2 mL, placing the mixture in a corundum crucible and placing the mixture in a muffle furnace, and calcining the mixture at 400° C. for 3 h to obtain calcined slag;

[0149] (3) mixing sodium hypochlorite and 4 mol / L hydrochloric acid solution in a mass ratio of 1:4 to obtain a first leachate;

[0150] The roasted slag was mixed evenly with the first leaching solution in a reaction kettle, leached at 55°C for 1 hour, then leached for 1 hour by adding 6 mol / L sulfuric acid solution, and filtered to obtain a leaching solution;

[0151] The solid-liquid ratio of the roasted slag, the first leaching solution and the sulfuric acid solution is 1g:4mL:2mL.

[0152] (4) adding 15 wt % sulfuric acid solution to the leaching solution, introducing hydrogen sulfide gas at a flow rate of 2 L / min, reacting at 80° C. for 5 h, and filtering by pressure to obtain a filtrate;

[0153] The volume ratio of the leaching solution to the sulfuric acid solution is 5:1.

[0154] (5) adding a 4N pure zinc plate to the filtrate to carry out a replacement reaction for 48 hours to obtain sponge indium;

[0155] (6) Press the sponge indium into a cake, cover the surface of the sponge indium with caustic soda, put it into an induction medium frequency furnace, heat treat it at 400° C. for 4 h, remove the upper scum, and obtain crude indium.

[0156] The mass ratio of the caustic soda to sponge indium is 0.5:1.

[0157] Comparative Example 5

[0158] A method for recovering indium from an indium-containing material comprises the following steps:

[0159] (1) Spread the indium-containing material on a stainless steel tray, put it into a drying oven, dry it, take it out, and grind it to 100 mesh to obtain indium-containing powder;

[0160] The main components of the indium-containing material are: In 1.32%, Pb 10.21%, Sn 8.93%, Zn 27.95%, Cu 5.2%, S 31.58%, Cl 1.3%, and other elements 14.83%.

[0161] (2) mixing the indium-containing powder and 98 wt % sulfuric acid solution in a solid-liquid ratio of 1 g:2 mL, placing the mixture in a corundum crucible and placing the mixture in a muffle furnace, and calcining the mixture at 400° C. for 3 h to obtain calcined slag;

[0162] (3) mixing sodium hypochlorite and 4 mol / L hydrochloric acid solution in a mass ratio of 1:4 to obtain a first leachate;

[0163] The roasted slag was mixed evenly with the first leaching solution in a reaction kettle, leached at 55°C for 1 hour, then leached for 1 hour by adding 6 mol / L sulfuric acid solution, and filtered to obtain a leaching solution;

[0164] The solid-liquid ratio of the roasted slag, the first leaching solution and the sulfuric acid solution is 1g:4mL:2mL.

[0165] (4) adding 15 wt % sulfuric acid solution to the leaching solution, introducing hydrogen sulfide gas at a flow rate of 2 L / min, reacting at 80° C. for 5 h, and filtering by pressure to obtain a filtrate;

[0166] The volume ratio of the leaching solution to the sulfuric acid solution is 5:1.

[0167] (5) The pH of the filtrate was adjusted to 3.5 with sodium carbonate, and a 4N purity zinc plate was added to carry out a replacement reaction for 48 hours to obtain sponge indium;

[0168] (6) Press the sponge indium into a cake, cover the surface of the sponge indium with caustic soda, put it into an induction medium frequency furnace, heat treat it at 400° C. for 4 h, remove the upper scum, and obtain crude indium.

[0169] The mass ratio of the caustic soda to sponge indium is 0.5:1.

[0170] Test Case

[0171] The lead removal rate, tin removal rate, indium metal recovery rate and crude indium purity of the embodiments and comparative examples were calculated.

[0172] Table 1

[0173]

[0174] As can be seen from Table 1, the present invention can effectively recover indium from indium-containing materials with high lead, high tin, high zinc and high sulfur to obtain crude indium, and effectively remove lead, tin, zinc, sulfur and some other impurity elements, and has broad application prospects.

[0175] 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) grinding an indium-containing material to obtain an indium-containing powder; (2) mixing the indium-containing powder and the sulfuric acid solution uniformly, and roasting to obtain roasted slag; (3) leaching the roasted slag with a first leaching solution and then leaching it with a second leaching solution to obtain a leaching solution; (4) adding sulfuric acid solution to the leaching solution, introducing hydrogen sulfide gas to react, and filtering to obtain a filtrate; (5) adjusting the pH of the filtrate to 1.5-2.5 with sodium carbonate, adding a zinc plate to carry out a replacement reaction, and obtaining sponge indium; (6) Covering the surface of sponge indium with caustic soda and subjecting it to heat treatment to obtain crude indium.

2. The method for recovering indium from an indium-containing material according to claim 1, characterized in that: The main components of the indium-containing material are: 0.8-2% In, 8-12% Pb, 6-10% Sn, 25-30% Zn, 4-6% Cu, 28-35% S, and 1-2% Cl.

3. The method for recovering indium from an indium-containing material according to claim 1, characterized in that: The mass mixing ratio of the indium-containing powder and 95-98wt% concentrated sulfuric acid is (2-4):1; The concentration of the sulfuric acid solution in step (2) is 95-98 wt %.

4. The method for recovering indium from an indium-containing material according to claim 1, characterized in that: The calcination temperature is 350-450°C and the calcination time is 2-5h; The heat treatment temperature is 250-350° C., and the heat treatment time is 2-5 hours.

5. The method for recovering indium from an indium-containing material according to claim 1, characterized in that: The first acid solution includes an oxidant and a first acid solution, and the mass ratio of the oxidant to the first acid solution is 1:(3-5); The oxidant includes at least one of sodium hypochlorite and potassium permanganate; The first acid solution includes at least one of a 2-4 mol / L hydrochloric acid solution, a 2-4 mol / L acetic acid solution, a 2-4 mol / L oxalic acid solution, and a 2-4 mol / L nitric acid solution; The second leaching solution includes at least one of a 4-6 mol / L nitric acid solution and a 4-6 mol / L sulfuric acid solution.

6. The method for recovering indium from an indium-containing material according to claim 1, characterized in that: The solid-liquid ratio of the roasted slag, the first leaching solution and the second leaching solution is 1g: (4-6)mL: (2-3)mL; and / or The leaching temperature is 50-60° C. and the leaching time is 1-4 hours.

7. The method for recovering indium from indium-containing materials according to claim 1, characterized in that: The concentration of the sulfuric acid solution in step (4) is 10-20 wt %; and / or The volume ratio of the leaching solution to the sulfuric acid solution is (4-6):

1.

8. The method for recovering indium from indium-containing materials according to claim 1, characterized in that: The amount of hydrogen sulfide gas introduced is 1-2 L / min.

9. The method for recovering indium from indium-containing materials according to claim 1, characterized in that: The reaction temperature in step (4) is 70-90° C. and the reaction time is 4-6 hours.

10. The method for recovering indium from indium-containing materials according to claim 1, characterized in that: The mass ratio of the caustic soda to sponge indium is (0.4-0.5):1.

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