Method for separating indium and tin from high-acidity indium and tin mixed solution

Abstract

The invention relates to a method for separating material components in nonferrous metallurgy, in particular to a method for separating indium and tin from a high-acidity indium and tin mixed solution. The method comprises the following steps: taking a certain amount of indium-tin mixed solution, firstly adding a certain amount of arsenic-containing detinning agent into the indium-tin mixed solution, then adding a sufficient amount of oxidant, carrying out arsenic and tin co-precipitation reaction, and after the reaction is finished, filtering to obtain detinned slag and detinned liquid. On the basis of the principle of arsenic and tin co-precipitation reaction, tin is separated from the high-acidity indium-tin mixed solution by adopting the arsenic-containing detinning agent, the highest detinning rate can reach 99% or above, indium is reserved in the solution, the loss is 5% or below, and the purpose of separating indium and tin in the solution is achieved. The method is short in technological process, easy to operate, good in indium and tin separation effect, low in cost and easy to apply in an engineering mode.

Description

Technical Field

[0001] The invention relates to a method for separating material components in nonferrous smelting, and in particular to a method for separating indium tin from a high-acidity indium tin mixed solution. Background Art

[0002] Separating indium from tin is a crucial step in extracting indium from materials such as zinc smelting residues, indium tin oxide target waste, used liquid crystal displays, and indium tin alloys. Acid leaching is considered an effective and versatile method for extracting indium from indium tin materials and has been implemented in production. However, while acid is typically used to dissolve indium from the material, tin is also leached out and coexists with indium ions in the leachate. This prevents effective separation of indium and tin during subsequent extraction, stripping, and precipitation steps. Therefore, removing tin from the acid leachate is essential. The key to this process is the effective separation of indium and tin.

[0003] The main methods for separating indium and tin include metal replacement, hydrolysis precipitation, sulfide precipitation, and extraction. The metal replacement method usually uses zinc powder for replacement, which has a good tin removal effect, but the indium content in the reduced tin slag is relatively high, and the separation of indium and tin is not complete. In the hydrolysis precipitation method, the generated Sn(OH)4 acts as a gelling material, making solid-liquid separation difficult, and the adsorption of indium on the surface of tin hydroxide is inevitable, resulting in a significant reduction in the direct recovery rate of indium. The sulfide precipitation method requires a sulfiding agent as a precipitant, which is prone to produce highly toxic hydrogen sulfide gas for high-acidity solutions. During the extraction and separation process, tin will also enter the extract P204 and gradually enrich in the system, resulting in a decrease in extraction capacity. These methods each have their own advantages, but all have shortcomings such as incomplete indium and tin separation, lengthy process flows, or low efficiency. Summary of the Invention

[0004] In view of the shortcomings of the existing technology, the purpose of the present invention is to provide a method for separating indium tin from a high-acidity indium tin mixed solution, which can achieve efficient separation of indium tin and obtain a low-tin indium-rich solution and tin-removed slag.

[0005] The present invention achieves the above-mentioned object through the following technical solutions:

[0006] A method for separating indium tin from a high-acidity indium tin mixed solution comprises the following steps: adding an arsenic-containing tin removal agent to an indium tin mixed solution having a sulfuric acid concentration greater than 1 mol / L to carry out a co-precipitation reaction of arsenic and tin to obtain an arsenic-tin precipitate and an indium solution after precipitating tin.

[0007] In the arsenic and tin co-precipitation reaction, arsenic is in a pentavalent state and tin is in a tetravalent state.

[0008] The present invention adopts an arsenic-containing tin stripping agent to react with an indium-tin mixed solution, and generates an arsenic-tin precipitate that is difficult to dissolve in a high-acidity system through a co-precipitation reaction of arsenic and tin, thereby realizing the separation of indium-tin in a high-acidity system.

[0009] The arsenic-containing detinning agent includes soluble arsenite, arsenate and arsenic trioxide.

[0010] When the detinning agent includes at least one of soluble arsenite and arsenic trioxide, and / or the tin in the indium tin mixed solution is in a divalent state, after the detinning agent is added to the indium tin mixed solution, a sufficient amount of oxidant hydrogen peroxide is added to the solution to keep the arsenic and tin in the mixed solution in a high valence state.

[0011] The molar ratio of arsenic to tin in the arsenic-tin coprecipitation reaction is 0.75-2.0.

[0012] Optionally, the detinning agent and / or oxidizing agent hydrogen peroxide are added in small amounts multiple times to carry out an arsenic-tin co-precipitation reaction for detin removal.

[0013] The arsenic and tin co-precipitation reaction is carried out at 60-90°C.

[0014] The arsenic and tin co-precipitation reaction is carried out at 200-600 rpm, and the reaction time is 0.5-1.5 h.

[0015] The sufficient amount of hydrogen peroxide as the oxidant is 2.0-4.0 times the theoretical amount required to ensure the oxidation of arsenic and tin.

[0016] The present invention mainly relates to the following reaction:

[0017] Sn 2+ +H2O2+2H + →Sn 4+ +2H2O

[0018] H3AsO3+H2O2→H3AsO4+H2O

[0019] 3Sn 4+ +4H3AsO4→Sn3(AsO4)4↓+12H +

[0020] Sn 4+ +2H3AsO4+H2O→Sn(HAsO4)2·H2O↓+4H +

[0021] Based on the principle of arsenic and tin co-precipitation, this method uses an arsenic-containing tin removal agent to separate tin from a highly acidic indium-tin mixed solution. The tin removal rate can reach over 99%, while indium remains in the solution with a loss of less than 5%, achieving the goal of separating indium-tin from the solution. This method has a short process flow, simple operation, good indium-tin separation efficiency, low cost, and is easily applicable in engineering applications. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] To more clearly illustrate the technical solution of the present invention, the accompanying drawings used in the embodiments will be briefly described below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope of protection of the present invention. In the various drawings, similar components are numbered similarly.

[0023] Figure 1 The XRD pattern of the detinning slag obtained by the arsenic-tin co-precipitation reaction in the embodiment of the present disclosure is shown.

[0024] Figure 2 The SEM spectrum of the detinning slag obtained by the arsenic-tin co-precipitation reaction in the embodiment of the present disclosure is shown.

[0025] Figure 3 A schematic flow chart of a method for separating indium tin from a high-acidity indium tin mixed solution provided by an embodiment of the present disclosure is shown. DETAILED DESCRIPTION

[0026] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0027] like Figure 3 As shown, the present invention provides a method for separating indium tin from a high-acidity indium tin mixed solution, the method specifically comprising the following steps:

[0028] Take a certain amount of indium-tin mixed solution, first add a certain amount of arsenic-containing detinting agent to the indium-tin mixed solution, then add sufficient oxidant to carry out the arsenic and tin co-precipitation reaction. After the reaction is completed, filter to obtain detin-removing slag and detin-removing liquid.

[0029] Furthermore, the concentration of sulfuric acid in the indium-tin mixed solution is greater than 1 mol / L; and the valence state of tin therein is divalent, tetravalent, or a mixture of divalent and tetravalent.

[0030] Furthermore, the amount of the arsenic-containing detinning agent added is such that the molar ratio of arsenic to tin in the mixed solution of indium tin is 0.75-2.0.

[0031] Furthermore, the arsenic-containing detinning agent is at least one of soluble arsenite, arsenate, and arsenic trioxide.

[0032] Furthermore, the oxidant is hydrogen peroxide, and its dosage is 2.0-4.0 times the theoretical dosage required to ensure the oxidation of arsenic and tin.

[0033] Furthermore, the process parameters of the arsenic and tin co-precipitation reaction are specifically as follows: a temperature of 60-90° C., a stirring rate of 200-600 rpm, and a reaction time of 0.5-1.5 h.

[0034] Furthermore, the tin removal rate of the method is not less than 85%, while indium remains in the solution with a loss of less than 5%.

[0035] A kind of tin, which is prepared by adopting the above method.

[0036] Example 1

[0037] Take 200 mL of indium-tin mixed solution (In 3+ 4.403 g / L, Sn 2+ :4.838g / L, H2SO4:1.5mol / L), first add the detinning agent sodium arsenate (As / Sn molar ratio is 0.75), then add enough oxidant hydrogen peroxide (H2O2 / Sn molar ratio = 2) to oxidize Sn 2+ Sn 4+ The co-precipitation reaction conditions of arsenic and tin were as follows: reaction temperature 80°C, stirring speed 400 rpm, and reaction time 0.5 h. After the reaction was completed, the detinning residue and detinning liquid were filtered.

[0038] Examples 2-5

[0039] The only difference between Examples 2-5 and Example 1 is the amount of sodium arsenate used as the detinning agent, and the As / Sn molar ratios are 1.0, 1.25, 1.5, and 2.0, respectively.

[0040] Example 6

[0041] Take 200 mL of indium-tin mixed solution (In 3+ 32.55 g / L, Sn 4+ :4.935g / L, H2SO4: 2.0mol / L), first add the detinning agent sodium arsenite (As / Sn molar ratio is 1.25), then add enough oxidant hydrogen peroxide (H2O2 / As molar ratio = 2) to oxidize As 3+ As 5+ The co-precipitation reaction conditions of arsenic and tin were as follows: reaction temperature 85°C, stirring speed 400 rpm, and reaction time 1.0 h. After the reaction was completed, the detinning residue and detinning liquid were obtained by filtration.

[0042] Example 7

[0043] Take 200mL of indium tin mixed solution (In 3+ :4.83g / L,Sn 2+ :32.22g / L, H2SO4:1.8mol / L), first add the tin stripping agent sodium arsenite (As / Sn molar ratio is 1.5), then add enough oxidant hydrogen peroxide (H2O2 / (Sn+As) molar ratio = 3) to oxidize Sn 2+ 、As 3+ For Sn 4+ 、As5+ The co-precipitation reaction conditions of arsenic and tin were as follows: reaction temperature 75°C, stirring rate 300 rpm, and reaction time 1.0 h. After the reaction was completed, the detinning residue and detinning liquid were filtered.

[0044] Table 1. Effects of the indium-tin mixed solution detinification examples.

[0045]

[0046] The XRD pattern of the tin-removed slag obtained by the arsenic-tin co-precipitation reaction in the embodiment of the present disclosure is as follows: Figure 1 As shown; the SEM spectrum of the tin-removed slag obtained by the arsenic-tin co-precipitation reaction of the embodiment of the present disclosure is as follows Figure 2 shown.

[0047] The above describes in detail the method for separating indium tin from a high-acidity indium tin mixed solution provided in the examples of this application. The description of the above examples is only intended to help understand the method and core concept of this application; at the same time, those skilled in the art will find that the specific implementation methods and application scopes may vary based on the concept of this application. In summary, the contents of this specification should not be construed as limiting this application.

[0048] For example, certain words are used in the specification and claims to refer to specific components. Those skilled in the art should understand that hardware manufacturers may use different nouns to refer to the same component. This specification and claims do not use differences in names as a way to distinguish components, but use differences in the functions of components as the criteria for distinction. For example, "including" and "comprising" mentioned throughout the specification and claims are open-ended terms, so they should be interpreted as "including / including but not limited to". "Approximately" means that within an acceptable error range, those skilled in the art can solve the technical problems within a certain error range and basically achieve the technical effects. The subsequent description in the specification is a preferred embodiment of the present application, but the description is for the purpose of illustrating the general principles of the present application, and is not used to limit the scope of the present application. The scope of protection of the present application shall be as defined in the attached claims.

[0049] It should be understood that the term "and / or" as used herein is merely a description of the relationship between associated objects, indicating that three possible relationships exist. For example, "A and / or B" can represent: A exists alone, A and B exist simultaneously, or B exists alone. Furthermore, the character " / " in this document generally indicates that the associated objects are in an "or" relationship.

[0050] The above description shows and describes several preferred embodiments of the present application. However, as previously mentioned, it should be understood that the present application is not limited to the form disclosed herein and should not be construed as excluding other embodiments. Instead, the present application can be used in various other combinations, modifications, and environments and can be modified within the scope of the application concept described herein through the above teachings or technology or knowledge in the relevant field. Modifications and variations made by those skilled in the art that do not depart from the spirit and scope of the present application should be protected by the claims appended hereto.

Claims

1. A method for separating indium tin from a high-acidity indium tin mixed solution, characterized in that: The method specifically comprises the following steps: Take a certain amount of indium-tin mixed solution, first add a certain amount of arsenic-containing detinning agent to the indium-tin mixed solution, then add a sufficient amount of oxidant to carry out arsenic and tin co-precipitation reaction, and after the reaction is completed, filter to obtain detinning slag and detinning liquid.

2. The method according to claim 1, characterized in that The sulfuric acid concentration in the indium-tin mixed solution is greater than 1 mol / L.

3. The method according to claim 1, characterized in that The amount of the arsenic-containing detinning agent added is such that the molar ratio of arsenic to tin in the mixed solution of indium tin is 0.75-2.

0.

4. The method according to claim 1, characterized in that The arsenic-containing tin removal agent is at least one of soluble arsenite, arsenate, and arsenic trioxide.

5. The method according to claim 1, characterized in that The oxidant is hydrogen peroxide, and the amount used is 2.0-4.0 times the theoretical amount required to ensure the oxidation of arsenic and tin.

6. The method according to claim 1, characterized in that The process parameters of the arsenic and tin co-precipitation reaction are specifically: at a temperature of 60-90° C., a stirring rate of 200-600 rpm, and a reaction time of 0.5-1.5 h.

7. The method according to claim 1, characterized in that The tin removal rate of the method is more than 99%, while indium remains in the solution with a loss of less than 5%.

8. Tin, characterized in that The tin is prepared by the method according to any one of claims 1 to 7.

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