Method for removing iron and tin in indium oxide powder

Abstract

The invention discloses a method for removing iron and tin in indium oxide powder, and belongs to the technical field of semiconductor materials.According to the method, oxidation and acid leaching are conducted on the indium oxide powder under the condition that the pH is 1-2, hydrolysis of indium is effectively prevented, meanwhile, the valence states of iron and tin are improved, then cation resin is used for adsorption iron removal, tin removal is conducted through sodium sulfide under the condition that the pH is-2--1, and the tin content of the indium oxide powder is reduced. According to the method, indium is precipitated by adopting a sodium hydroxide solution, and indium hydroxide is converted into indium oxide through two times of heat treatment, so that the iron and tin in the indium oxide powder are effectively removed, the impurity removal efficiency is high, the indium oxide yield is high, and the method has a wide application prospect.

Description

Technical Field

[0001] The present invention relates to the technical field of semiconductor materials, and in particular to a method for removing iron and tin from indium oxide powder. Background Art

[0002] Indium oxide is a typical n-type semiconductor with good electron mobility and optical properties. It is widely used in gas sensors, solar cells, photocatalysts and other fields.

[0003] At present, industrially prepared indium oxide powder contains many impurities, such as iron and tin. If they are not removed, they will have a great impact on the performance of indium oxide. Therefore, in response to the above problems, it is urgent to develop a method for stepwise removal of iron and tin from indium oxide powder to solve the impact of impurity metals on the performance of indium oxide products, improve product qualification rate, and increase corporate benefits. 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 removing iron and tin from indium oxide powder, which can effectively improve the removal of iron and tin from indium oxide powder, has a high impurity removal effect, and has a high indium oxide yield, and has broad application prospects.

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

[0006] A method for removing iron and tin from indium oxide powder comprises the following steps:

[0007] (1) mixing indium oxide powder, a first sulfuric acid solution, and hydrogen peroxide uniformly, adding a second sulfuric acid solution to adjust the pH to 1-2, and reacting to obtain a mixed solution;

[0008] (2) adding cationic resin to the mixed solution, stirring evenly, and separating the solid and liquid to obtain an iron removal solution;

[0009] (3) adding sodium sulfide to the iron removal solution, adding a third sulfuric acid solution to adjust the pH to -2 to -1, reacting, filtering, and obtaining a tin removal solution;

[0010] (4) adjusting the pH of the tin removal solution to 10-12 with a sodium hydroxide solution, reacting, and filtering to obtain crude indium hydroxide;

[0011] (5) The crude indium hydroxide is subjected to a first heat treatment under inert gas protection, and then to a second heat treatment to obtain indium oxide powder.

[0012] The present invention carries out oxidation acid leaching of indium oxide powder at a pH of 1 to 2, effectively preventing indium from hydrolyzing while increasing the valence of iron and tin. Then, cationic resin is used for adsorption to remove iron, and sodium sulfide is used for tin removal at a pH of -2 to -1 (Sn 4++2Na2S=SnS2+4Na + ), then using sodium hydroxide solution to precipitate indium, and finally through two heat treatments, the indium hydroxide is converted into indium oxide, which effectively improves the removal of iron and tin in the indium oxide powder, has high impurity removal efficiency, and high indium oxide yield, and has broad application prospects.

[0013] As a preferred embodiment of the present invention, the indium content in the indium oxide powder is 90-95%, the tin content is 45-100 ppm, and the iron content is 25-50 ppm.

[0014] As a preferred embodiment of the present invention, the solid-to-liquid ratio of the indium oxide powder, the first sulfuric acid solution, and the hydrogen peroxide is 1 kg: (4-6) L: (0.05-0.1) L.

[0015] As a preferred embodiment of the present invention, the reaction temperature in step (1) is 45-55° C., and the reaction time is 1-3 h.

[0016] As a preferred embodiment of the present invention, the cationic resin is a D001 type sulfonated styrene cationic resin;

[0017] The solid-liquid ratio of the cationic resin and the mixed solution is (50-100) mg:1L.

[0018] By using D001 sulfonated styrene cationic resin and controlling its solid-liquid ratio with the mixed solution, it can first adsorb the cations in the mixed solution, and then use the hydrogen ions released by the acidic groups to exchange with iron ions, thereby effectively removing iron impurities.

[0019] As a preferred embodiment of the present invention, the solid-liquid ratio of the sodium sulfide and the iron removal liquid is (5-10) g:1L.

[0020] As a preferred embodiment of the present invention, the reaction temperature in step (3) is 45-55° C., and the reaction time is 20-60 min.

[0021] As a preferred embodiment of the present invention, the concentration of the first sulfuric acid solution is 6 to 8 wt%;

[0022] The concentration of the second sulfuric acid solution is 95-98 wt %;

[0023] The concentration of the third sulfuric acid solution is 95-98 wt %.

[0024] As a preferred embodiment of the present invention, the concentration of the hydrogen peroxide is 27.5 to 60 wt%.

[0025] As a preferred embodiment of the present invention, the temperature of the first heat treatment is 300-400° C., and the time is 3-6 hours.

[0026] As a preferred embodiment of the present invention, the temperature of the second heat treatment is 600-700° C., and the time is 4-8 hours.

[0027] The beneficial effects of the present invention are as follows: the present invention carries out oxidative acid leaching of indium oxide powder at a pH of 1 to 2, effectively preventing indium from hydrolyzing while increasing the valence of iron and tin, and then uses cationic resin to adsorb iron, and then uses sodium sulfide to remove tin (Sn) at a pH of -2 to -1. 4+ +2Na2S=SnS2+4Na + ), then using sodium hydroxide solution to precipitate indium, and finally through two heat treatments, the indium hydroxide is converted into indium oxide, which effectively improves the removal of iron and tin in the indium oxide powder, has high impurity removal efficiency, and high indium oxide yield, and has broad application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 Flowchart of a method for removing iron and tin from indium oxide powder. DETAILED DESCRIPTION

[0029] To make the purpose, technical solutions, and advantages of the embodiments of this application more clear, the technical solutions in the embodiments of this application will be clearly and completely described below. Obviously, the described embodiments are part of the embodiments of this application, not all of them. Based on the embodiments of this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0030] In this 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.

[0031] In this application, when referring to numerical ranges, unless otherwise specified, the numerical ranges are considered continuous and include the minimum and maximum values ​​of the range, as well as every value between such minimum and maximum values. Further, when a range refers to an integer, every integer between the minimum and maximum values ​​of the range is included. In addition, when multiple ranges are provided to describe a feature or characteristic, the ranges can be combined. In other words, unless otherwise specified, all ranges disclosed herein should be understood to include any and all subranges subsumed therein.

[0032] In the present application, there is no particular limitation on the specific dispersion and stirring treatment methods.

[0033] 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.

[0034] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of the present invention, "plurality" means at least two, such as two, three, etc., unless otherwise specifically defined.

[0035] The following examples are provided to facilitate understanding of the present invention. These examples are not provided to limit the scope of the claims.

[0036] Example 1

[0037] like Figure 1 As shown, the present invention provides a method for removing iron and tin from indium oxide powder, comprising the following steps:

[0038] (1) Indium oxide powder is provided, wherein the indium content of the indium oxide powder is 99.95%, the tin content is 54 ppm, and the iron content is 49 ppm.

[0039] Indium oxide powder, 8wt% sulfuric acid solution, and 30wt% hydrogen peroxide were mixed at a solid-liquid ratio of 1 kg:5 L:0.08 L, and 95wt% sulfuric acid solution was added to adjust the pH to 2. The mixture was stirred at 50°C and 200 rpm for 2 h to obtain a mixed solution.

[0040] (2) adding D001 type sulfonated styrene cationic resin to the mixed solution, stirring evenly, and separating the solid and liquid to obtain an iron removal liquid;

[0041] The solid-liquid ratio of the D001 type sulfonated styrene cationic resin and the mixed solution is 80 mg:1 L.

[0042] (3) adding sodium sulfide to the iron removal solution, adding a 95 wt% sulfuric acid solution to adjust the pH to -1, stirring at 45°C and 120 rpm for 2 h, and filtering to obtain a tin removal solution;

[0043] The solid-liquid ratio of the sodium sulfide and the iron removal liquid is 8g:1L.

[0044] (4) adjusting the pH of the tin removal solution to 11 with a 46 wt % sodium hydroxide solution, reacting until no white precipitate is produced, standing for 2 h, and filtering to obtain crude indium hydroxide;

[0045] (5) The crude indium hydroxide was loaded into a graphite boat, which was then placed in a tubular furnace. Nitrogen was introduced at a rate of 5 L / min, and the temperature was increased to 400°C at a heating rate of 5°C / min for heat treatment for 4 h. The temperature was then increased to 600°C at a heating rate of 5°C / min for heat treatment for 6 h to obtain indium oxide powder.

[0046] Example 2

[0047] like Figure 1 As shown, the present invention provides a method for removing iron and tin from indium oxide powder, comprising the following steps:

[0048] (1) Indium oxide powder is provided, wherein the indium content of the indium oxide powder is 99.95%, the tin content is 54 ppm, and the iron content is 49 ppm.

[0049] Indium oxide powder, 8wt% sulfuric acid solution, and 30wt% hydrogen peroxide were mixed at a solid-liquid ratio of 1 kg:5 L:0.08 L, and 95wt% sulfuric acid solution was added to adjust the pH to 2. The mixture was stirred at 50°C and 200 rpm for 2 h to obtain a mixed solution.

[0050] (2) adding D001 type sulfonated styrene cationic resin to the mixed solution, stirring evenly, and separating the solid and liquid to obtain an iron removal liquid;

[0051] The solid-liquid ratio of the D001 type sulfonated styrene cationic resin and the mixed solution is 80 mg:1 L.

[0052] (3) adding sodium sulfide to the iron removal solution, adding a 95 wt% sulfuric acid solution to adjust the pH to -1, stirring at 45°C and 120 rpm for 2 h, and filtering to obtain a tin removal solution;

[0053] The solid-liquid ratio of the sodium sulfide and the iron removal liquid is 8g:1L.

[0054] (4) adjusting the pH of the tin removal solution to 11 with a 46 wt % sodium hydroxide solution, reacting until no white precipitate is produced, standing for 2 h, and filtering to obtain crude indium hydroxide;

[0055] (5) The crude indium hydroxide was loaded into a graphite boat, which was then placed in a tubular furnace. Nitrogen was introduced at a rate of 5 L / min, and the temperature was increased to 300°C at a heating rate of 5°C / min for heat treatment for 4 h. The temperature was then increased to 700°C at a heating rate of 5°C / min for heat treatment for 6 h to obtain indium oxide powder.

[0056] Example 3

[0057] like Figure 1 As shown, the present invention provides a method for removing iron and tin from indium oxide powder, comprising the following steps:

[0058] (1) Indium oxide powder is provided, wherein the indium content of the indium oxide powder is 99.95%, the tin content is 54 ppm, and the iron content is 49 ppm.

[0059] Indium oxide powder, 8 wt% sulfuric acid solution, and 30 wt% hydrogen peroxide were mixed at a solid-liquid ratio of 1 kg:4 L:0.1 L, 95 wt% sulfuric acid solution was added to adjust the pH to 1, and the mixture was stirred at 50°C and 200 rpm for 2 h to obtain a mixed solution;

[0060] (2) adding D001 type sulfonated styrene cationic resin to the mixed solution, stirring evenly, and separating the solid and liquid to obtain an iron removal liquid;

[0061] The solid-liquid ratio of the D001 type sulfonated styrene cationic resin and the mixed solution is 50 mg:1 L.

[0062] (3) adding sodium sulfide to the iron removal solution, adding a 95 wt% sulfuric acid solution to adjust the pH to -1, stirring at 45°C and 120 rpm for 2 h, and filtering to obtain a tin removal solution;

[0063] The solid-liquid ratio of the sodium sulfide and the iron removal liquid is 10g:1L.

[0064] (4) adjusting the pH of the tin removal solution to 11 with a 46 wt % sodium hydroxide solution, reacting until no white precipitate is produced, standing for 2 h, and filtering to obtain crude indium hydroxide;

[0065] (5) The crude indium hydroxide was loaded into a graphite boat, which was then placed in a tubular furnace. Nitrogen was introduced at a rate of 5 L / min, and the temperature was increased to 400°C at a heating rate of 5°C / min for heat treatment for 4 h. The temperature was then increased to 600°C at a heating rate of 5°C / min for heat treatment for 6 h to obtain indium oxide powder.

[0066] Example 4

[0067] like Figure 1 As shown, the present invention provides a method for removing iron and tin from indium oxide powder, comprising the following steps:

[0068] (1) Indium oxide powder is provided, wherein the indium content of the indium oxide powder is 99.95%, the tin content is 54 ppm, and the iron content is 49 ppm.

[0069] Indium oxide powder, 8 wt% sulfuric acid solution, and 30 wt% hydrogen peroxide were mixed at a solid-liquid ratio of 1 kg:4 L:0.05 L, 95 wt% sulfuric acid solution was added to adjust the pH to 2, and the mixture was stirred at 50°C and 200 rpm for 2 h to obtain a mixed solution;

[0070] (2) adding D001 type sulfonated styrene cationic resin to the mixed solution, stirring evenly, and separating the solid and liquid to obtain an iron removal liquid;

[0071] The solid-liquid ratio of the D001 type sulfonated styrene cationic resin and the mixed solution is 100 mg:1 L.

[0072] (3) adding sodium sulfide to the iron removal solution, adding a 95 wt% sulfuric acid solution to adjust the pH to -1, stirring at 45°C and 120 rpm for 2 h, and filtering to obtain a tin removal solution;

[0073] The solid-liquid ratio of the sodium sulfide and the iron removal liquid is 5g:1L.

[0074] (4) adjusting the pH of the tin removal solution to 11 with a 46 wt % sodium hydroxide solution, reacting until no white precipitate is produced, standing for 2 h, and filtering to obtain crude indium hydroxide;

[0075] (5) The crude indium hydroxide was loaded into a graphite boat, which was then placed in a tubular furnace. Nitrogen was introduced at a rate of 5 L / min, and the temperature was increased to 400°C at a heating rate of 5°C / min for heat treatment for 4 h. The temperature was then increased to 600°C at a heating rate of 5°C / min for heat treatment for 6 h to obtain indium oxide powder.

[0076] Comparative Example 1

[0077] A method for removing iron and tin from indium oxide powder comprises the following steps:

[0078] (1) Indium oxide powder is provided, wherein the indium content of the indium oxide powder is 99.95%, the tin content is 54 ppm, and the iron content is 49 ppm.

[0079] Indium oxide powder and 8 wt% sulfuric acid solution were mixed at a solid-liquid ratio of 1 kg:5 L, 95 wt% sulfuric acid solution was added to adjust the pH to 2, and the mixture was stirred at 200 rpm at 50°C for 2 h to obtain a mixed solution;

[0080] (2) adding D001 type sulfonated styrene cationic resin to the mixed solution, stirring evenly, and separating the solid and liquid to obtain an iron removal liquid;

[0081] The solid-liquid ratio of the D001 type sulfonated styrene cationic resin and the mixed solution is 80 mg:1 L.

[0082] (3) adding sodium sulfide to the iron removal solution, adding a 95 wt% sulfuric acid solution to adjust the pH to -1, stirring at 45°C and 120 rpm for 2 h, and filtering to obtain a tin removal solution;

[0083] The solid-liquid ratio of the sodium sulfide and the iron removal liquid is 8g:1L.

[0084] (4) adjusting the pH of the tin removal solution to 11 with a 46 wt % sodium hydroxide solution, reacting until no white precipitate is produced, standing for 2 h, and filtering to obtain crude indium hydroxide;

[0085] (5) The crude indium hydroxide was loaded into a graphite boat, which was then placed in a tubular furnace. Nitrogen was introduced at a rate of 5 L / min, and the temperature was increased to 400°C at a heating rate of 5°C / min for heat treatment for 4 h. The temperature was then increased to 600°C at a heating rate of 5°C / min for heat treatment for 6 h to obtain indium oxide powder.

[0086] Comparative Example 2

[0087] A method for removing iron and tin from indium oxide powder comprises the following steps:

[0088] (1) Indium oxide powder is provided, wherein the indium content of the indium oxide powder is 99.95%, the tin content is 54 ppm, and the iron content is 49 ppm.

[0089] Indium oxide powder, 8 wt% sulfuric acid solution, and 30 wt% hydrogen peroxide were mixed at a solid-liquid ratio of 1 kg: 5 L: 0.08 L, 95 wt% sulfuric acid solution was added to adjust the pH to 3, and the mixture was stirred at 50°C and 200 rpm for 2 h to obtain a mixed solution;

[0090] (2) adding T-IRR resin to the mixed solution, stirring evenly, and separating the solid and liquid to obtain an iron removal solution;

[0091] The solid-liquid ratio of the T-IRR resin and the mixed solution is 80 mg:1 L.

[0092] (3) adding sodium sulfide to the iron removal solution, adding a 95 wt% sulfuric acid solution to adjust the pH to -1, stirring at 45°C and 120 rpm for 2 h, and filtering to obtain a tin removal solution;

[0093] The solid-liquid ratio of the sodium sulfide and the iron removal liquid is 8g:1L.

[0094] (4) adjusting the pH of the tin removal solution to 11 with a 46 wt % sodium hydroxide solution, reacting until no white precipitate is produced, standing for 2 h, and filtering to obtain crude indium hydroxide;

[0095] (5) The crude indium hydroxide was loaded into a graphite boat, which was then placed in a tubular furnace. Nitrogen was introduced at a rate of 5 L / min, and the temperature was increased to 400°C at a heating rate of 5°C / min for heat treatment for 4 h. The temperature was then increased to 600°C at a heating rate of 5°C / min for heat treatment for 6 h to obtain indium oxide powder.

[0096] Comparative Example 3

[0097] A method for removing iron and tin from indium oxide powder comprises the following steps:

[0098] (1) Indium oxide powder is provided, wherein the indium content of the indium oxide powder is 99.95%, the tin content is 54 ppm, and the iron content is 49 ppm.

[0099] Indium oxide powder, 8wt% sulfuric acid solution, and 30wt% hydrogen peroxide were mixed at a solid-liquid ratio of 1 kg:5 L:0.08 L, and 95wt% sulfuric acid solution was added to adjust the pH to 2. The mixture was stirred at 50°C and 200 rpm for 2 h to obtain a mixed solution.

[0100] (2) adding D001 type sulfonated styrene cationic resin to the mixed solution, stirring evenly, and separating the solid and liquid to obtain an iron removal liquid;

[0101] The solid-liquid ratio of the D001 type sulfonated styrene cationic resin and the mixed solution is 80 mg:1 L.

[0102] (3) adding sodium sulfide to the iron removal solution, adding a 95 wt% sulfuric acid solution to adjust the pH to 1, stirring at 45°C and 120 rpm for 2 h, and filtering to obtain a detinning solution;

[0103] The solid-liquid ratio of the sodium sulfide and the iron removal liquid is 8g:1L.

[0104] (4) adjusting the pH of the tin removal solution to 11 with a 46 wt % sodium hydroxide solution, reacting until no white precipitate is produced, standing for 2 h, and filtering to obtain crude indium hydroxide;

[0105] (5) The crude indium hydroxide was loaded into a graphite boat, which was then placed in a tubular furnace. Nitrogen was introduced at a rate of 5 L / min, and the temperature was increased to 400°C at a heating rate of 5°C / min for heat treatment for 4 h. The temperature was then increased to 600°C at a heating rate of 5°C / min for heat treatment for 6 h to obtain indium oxide powder.

[0106] Comparative Example 4

[0107] A method for removing iron and tin from indium oxide powder comprises the following steps:

[0108] (1) Indium oxide powder is provided, wherein the indium content of the indium oxide powder is 99.95%, the tin content is 54 ppm, and the iron content is 49 ppm.

[0109] Indium oxide powder, 8wt% sulfuric acid solution, and 30wt% hydrogen peroxide were mixed at a solid-liquid ratio of 1 kg:5 L:0.08 L, and 95wt% sulfuric acid solution was added to adjust the pH to 2. The mixture was stirred at 50°C and 200 rpm for 2 h to obtain a mixed solution.

[0110] (2) adding D001 type sulfonated styrene cationic resin to the mixed solution, stirring evenly, and separating the solid and liquid to obtain an iron removal liquid;

[0111] The solid-liquid ratio of the D001 type sulfonated styrene cationic resin and the mixed solution is 80 mg:1 L.

[0112] (3) adjusting the pH of the tin removal solution to 11 with a 46 wt % sodium hydroxide solution, reacting until no white precipitate is produced, standing for 2 h, and filtering to obtain crude indium hydroxide;

[0113] (4) The crude indium hydroxide was loaded into a graphite boat, which was then placed in a tubular furnace. Nitrogen was introduced at a rate of 5 L / min, and the temperature was increased to 400°C at a heating rate of 5°C / min for heat treatment for 4 h. The temperature was then increased to 600°C at a heating rate of 5°C / min for heat treatment for 6 h to obtain indium oxide powder.

[0114] Comparative Example 5

[0115] A method for removing iron and tin from indium oxide powder comprises the following steps:

[0116] (1) Indium oxide powder is provided, wherein the indium content of the indium oxide powder is 99.95%, the tin content is 54 ppm, and the iron content is 49 ppm.

[0117] Indium oxide powder, 8wt% sulfuric acid solution, and 30wt% hydrogen peroxide were mixed at a solid-liquid ratio of 1 kg:5 L:0.08 L, and 95wt% sulfuric acid solution was added to adjust the pH to 2. The mixture was stirred at 50°C and 200 rpm for 2 h to obtain a mixed solution.

[0118] (2) adding D001 type sulfonated styrene cationic resin to the mixed solution, stirring evenly, and separating the solid and liquid to obtain an iron removal liquid;

[0119] The solid-liquid ratio of the D001 type sulfonated styrene cationic resin and the mixed solution is 80 mg:1 L.

[0120] (3) adding sodium sulfide to the iron removal solution, adding a 95 wt% sulfuric acid solution to adjust the pH to -1, stirring at 45°C and 120 rpm for 2 h, and filtering to obtain a tin removal solution;

[0121] The solid-liquid ratio of the sodium sulfide and the iron removal liquid is 8g:1L.

[0122] (4) adjusting the pH of the tin removal solution to 11 with a 46 wt % sodium hydroxide solution, reacting until no white precipitate is produced, standing for 2 h, and filtering to obtain crude indium hydroxide;

[0123] (5) The crude indium hydroxide was placed in a graphite boat, which was then placed in a tube furnace, and nitrogen was injected at a rate of 5 L / min. The temperature was then increased to 600°C at a heating rate of 5°C / min and heat-treated for 6 h to obtain indium oxide powder.

[0124] Comparative Example 6

[0125] A method for removing iron and tin from indium oxide powder comprises the following steps:

[0126] (1) Indium oxide powder is provided, wherein the indium content of the indium oxide powder is 99.95%, the tin content is 54 ppm, and the iron content is 49 ppm.

[0127] Indium oxide powder, 8wt% sulfuric acid solution, and 30wt% hydrogen peroxide were mixed at a solid-liquid ratio of 1 kg:5 L:0.08 L, and 95wt% sulfuric acid solution was added to adjust the pH to 2. The mixture was stirred at 50°C and 200 rpm for 2 h to obtain a mixed solution.

[0128] (2) adding D001 type sulfonated styrene cationic resin to the mixed solution, stirring evenly, and separating the solid and liquid to obtain an iron removal liquid;

[0129] The solid-liquid ratio of the D001 type sulfonated styrene cationic resin and the mixed solution is 80 mg:1 L.

[0130] (3) adding sodium sulfide to the iron removal solution, adding a 95 wt% sulfuric acid solution to adjust the pH to -1, stirring at 45°C and 120 rpm for 2 h, and filtering to obtain a tin removal solution;

[0131] The solid-liquid ratio of the sodium sulfide and the iron removal liquid is 2g:1L.

[0132] (4) adjusting the pH of the tin removal solution to 11 with a 46 wt % sodium hydroxide solution, reacting until no white precipitate is produced, standing for 2 h, and filtering to obtain crude indium hydroxide;

[0133] (5) The crude indium hydroxide was loaded into a graphite boat, which was then placed in a tubular furnace. Nitrogen was introduced at a rate of 5 L / min, and the temperature was increased to 400°C at a heating rate of 5°C / min for heat treatment for 4 h. The temperature was then increased to 600°C at a heating rate of 5°C / min for heat treatment for 6 h to obtain indium oxide powder.

[0134] Comparative Example 7

[0135] A method for removing iron and tin from indium oxide powder comprises the following steps:

[0136] (1) Indium oxide powder is provided, wherein the indium content of the indium oxide powder is 99.95%, the tin content is 54 ppm, and the iron content is 49 ppm.

[0137] Indium oxide powder, 8wt% sulfuric acid solution, and 30wt% hydrogen peroxide were mixed at a solid-liquid ratio of 1 kg:5 L:0.08 L, and 95wt% sulfuric acid solution was added to adjust the pH to 2. The mixture was stirred at 50°C and 200 rpm for 2 h to obtain a mixed solution.

[0138] (2) adding D001 type sulfonated styrene cationic resin to the mixed solution, stirring evenly, and separating the solid and liquid to obtain an iron removal liquid;

[0139] The solid-liquid ratio of the D001 type sulfonated styrene cationic resin and the mixed solution is 80 mg:1 L.

[0140] (3) adding sodium sulfide to the iron removal solution, adding a 95 wt% sulfuric acid solution to adjust the pH to -1, stirring at 45°C and 120 rpm for 2 h, and filtering to obtain a tin removal solution;

[0141] The solid-liquid ratio of the sodium sulfide and the iron removal liquid is 20g:1L.

[0142] (4) adjusting the pH of the tin removal solution to 11 with a 46 wt % sodium hydroxide solution, reacting until no white precipitate is produced, standing for 2 h, and filtering to obtain crude indium hydroxide;

[0143] (5) The crude indium hydroxide was loaded into a graphite boat, which was then placed in a tubular furnace. Nitrogen was introduced at a rate of 5 L / min, and the temperature was increased to 400°C at a heating rate of 5°C / min for heat treatment for 4 h. The temperature was then increased to 600°C at a heating rate of 5°C / min for heat treatment for 6 h to obtain indium oxide powder.

[0144] Test Case

[0145] GDMS was used to detect the iron and tin contents in indium oxide, and the iron and tin removal rates, as well as the indium oxide recovery rate, were calculated.

[0146] Table 1

[0147]

[0148]

[0149] As can be seen from Table 1, the present invention performs oxidative acid leaching of indium oxide powder at a pH of 1 to 2, effectively preventing indium from hydrolyzing while increasing the valence of iron and tin, and then uses cationic resin to adsorb iron, and then uses sodium sulfide to remove tin (Sn 4+ +2Na2S=SnS2+4Na +), then using sodium hydroxide solution to precipitate indium, and finally through two heat treatments, the indium hydroxide is converted into indium oxide, which effectively improves the removal of iron and tin in the indium oxide powder, has high impurity removal efficiency, and high indium oxide yield, and has broad application prospects.

[0150] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. A method for removing iron and tin from indium oxide powder, characterized in that: The following steps are involved: (1) mixing indium oxide powder, a first sulfuric acid solution, and hydrogen peroxide uniformly, adding a second sulfuric acid solution to adjust the pH to 1 to 2, reacting, and obtaining a mixed solution; (2) adding the cationic resin to the mixed solution, stirring evenly, and separating the solid and the liquid to obtain an iron removal liquid; (3) adding sodium sulfide to the iron removal liquid, adding the third sulfuric acid solution to adjust the pH to -2 to -1, reacting, filtering, and obtaining a tin removal liquid; (4) adjusting the pH of the tin removal solution to 10-12 with a sodium hydroxide solution, reacting, filtering, and obtaining crude indium hydroxide; (5) The crude indium hydroxide is subjected to a first heat treatment under the protection of an inert gas, and then subjected to a second heat treatment to obtain indium oxide powder.

2. The method for removing iron and tin from indium oxide powder according to claim 1, characterized in that: The solid-to-liquid ratio of the indium oxide powder, the first sulfuric acid solution, and the hydrogen peroxide solution is 1kg:(4-6)L:(0.05-0.1)L.

3. The method for removing iron and tin from indium oxide powder according to claim 1, characterized in that: The reaction temperature in step (1) is 45-55° C. and the reaction time is 1-3 h.

4. The method for removing iron and tin from indium oxide powder according to claim 1, characterized in that: The cationic resin is a D001 sulfonated styrene cationic resin; The solid-liquid ratio of the cationic resin and the mixed solution is (50-100) mg:1L.

5. The method for removing iron and tin from indium oxide powder according to claim 1, characterized in that: The solid-liquid ratio of the sodium sulfide and the iron removal liquid is (5-10) g:1L.

6. The method for removing iron and tin from indium oxide powder according to claim 1, characterized in that: The reaction temperature in step (3) is 45-55° C., and the reaction time is 20-60 min.

7. The method for removing iron and tin from indium oxide powder according to claim 1, characterized in that: The concentration of the first sulfuric acid solution is 6-8wt%; The concentration of the second sulfuric acid solution is 95-98wt%; The concentration of the third sulfuric acid solution is 95-98 wt %.

8. The method for removing iron and tin from indium oxide powder according to claim 1, characterized in that: The concentration of the hydrogen peroxide is 27.5-60wt%.

9. The method for removing iron and tin from indium oxide powder according to claim 1, characterized in that: The temperature of the first heat treatment is 300-400° C., and the time is 3-6 hours.

10. The method for removing iron and tin from indium oxide powder according to claim 1, characterized in that: The temperature of the second heat treatment is 600-700° C. and the time is 4-8 hours.

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