Method for removing tellurium in silver-containing material and silver-containing material

Abstract

The invention discloses a method for removing tellurium in a silver-containing material and the silver-containing material, the method for removing tellurium in the silver-containing material comprises the following steps: mixing the silver-containing material with sodium carbonate and anhydrous sodium tetraborate, and reacting at a first preset temperature of 1050-1150 DEG C for slagging smelting to obtain a reaction product, the mass part ratio of the silver-containing material to the sodium carbonate to the anhydrous sodium tetraborate is (9-11): (0.9-1.1): (2.8-3.1); and after the reaction is completed, filtering the reaction product to obtain the silver ingot.

Description

Technical Field

[0001] The invention relates to the field of chemical technology, and in particular to a method for removing tellurium from a silver-containing material and the silver-containing material. Background Art

[0002] Silver-containing materials usually refer to materials containing silver elements. Silver-containing materials usually contain tellurium. In order to improve product quality, in many application fields, such as jewelry making and the electronics industry, higher requirements are placed on the purity of silver. Tellurium as an impurity in silver-containing materials will reduce the purity of silver and affect its physical and chemical properties. Removing tellurium can improve the purity of silver and make it more in line with specific quality standards.

[0003] In addition, tellurium may react with other substances under certain conditions to produce corrosive substances. In the processing of silver-containing materials, the presence of tellurium may cause equipment corrosion, affecting production efficiency and equipment life. Removing tellurium can reduce this corrosion risk.

[0004] In the prior art, the electrolytic silver-containing material contains trace amounts of tellurium, which reduces the qualified rate of the electrolytic silver ingots (the qualified electrolytic silver ingots must comply with the GB / T 4135-2016 standard IC-Ag99.99 national standard 1 silver), and may even easily lead to excessive tellurium impurities in the silver powder, requiring repeated secondary electrolytic refining processes.

[0005] The above contents are only used to assist in understanding the technical solution of the present invention and do not constitute an admission that the above contents are prior art. Summary of the invention

[0006] The main purpose of the present invention is to provide a method for removing tellurium from a silver-containing material and a silver-containing material, aiming to solve the above-mentioned problems in the prior art.

[0007] To achieve the above object, the present invention provides a method for removing tellurium from a silver-containing material, the method comprising:

[0008] Mixing the silver-containing material with soda ash and anhydrous sodium tetraborate, reacting at a first preset temperature to perform slag smelting to obtain a reaction product, wherein the first preset temperature is 1050° C.-1150° C., and the mass fraction ratio of the silver-containing material, soda ash and anhydrous sodium tetraborate is (9-11): (0.9-1.1): (2.8-3.1);

[0009] After the reaction is complete, the reaction product is filtered to obtain a silver ingot.

[0010] Preferably, in the method for removing tellurium from the silver-containing material, the step of mixing the silver-containing material with soda ash and anhydrous sodium tetraborate, reacting at a first preset temperature to perform slag smelting, and obtaining a reaction product comprises the following chemical reaction:

[0011] In an alkaline environment at a first preset temperature, anhydrous sodium tetraborate interacts with tellurium in the silver-containing material to generate a tellurium-containing compound.

[0012] Preferably, in the method for removing tellurium from the silver-containing material, the step of mixing the silver-containing material with soda ash and anhydrous sodium tetraborate, reacting at a first preset temperature to perform slag smelting, and obtaining a reaction product comprises the following chemical reaction:

[0013] The boron in the sodium tetraborate combines with the tellurium at a first predetermined temperature to form borotellurate;

[0014] The soda ash reacts with the tellurium at a first predetermined temperature to form a volatile telluride or tellurate.

[0015] Preferably, in the method for removing tellurium from the silver-containing material, the silver-containing material is mixed with soda ash and anhydrous sodium tetraborate, and reacted at a first preset temperature to perform slag smelting to obtain a reaction product, including:

[0016] After mixing the silver-containing material with soda ash and anhydrous sodium tetraborate, reacting at a first stage temperature for a first time, wherein the first time is 30 minutes to 50 minutes and the first stage temperature is 900° C. to 950° C.;

[0017] After the first stage is completed, the reaction is carried out for a second time at the second stage temperature, wherein the second time is 50 min-70 min and the second stage temperature is 1100° C.-1150° C.

[0018] Preferably, in the method for removing tellurium from the silver-containing material, the first time length is 40 minutes, and the first stage temperature is 940° C.;

[0019] The second duration is 60 minutes, and the temperature of the first stage is 1100°C.

[0020] Preferably, in the method for removing tellurium from the silver-containing material, the first preset temperature is 1100°C.

[0021] Preferably, in the method for removing tellurium from the silver-containing material, the mass ratio of the silver-containing material, soda ash and anhydrous sodium tetraborate is 10:1:3.

[0022] Preferably, in the method for removing tellurium from the silver-containing material, before the step of mixing the silver-containing material with soda ash and anhydrous sodium tetraborate, reacting at a first preset temperature to perform slag smelting, and obtaining a reaction product, the removal method further comprises:

[0023] The silver-containing material is pretreated to remove impurities.

[0024] Preferably, in the method for removing tellurium from the silver-containing material, after the reaction is complete, filtering the reaction product to obtain a silver ingot, the method further comprises:

[0025] The obtained silver ingots are placed in a centrifuge and the residual filtrate is removed;

[0026] The silver ingot after removing the residual filtrate is immersed and washed in warm water at a second preset temperature, and the second preset temperature is 75°C-80°C.

[0027] In order to achieve the above object, the present invention further provides a silver-containing material, wherein the silver-containing material adopts the above method for removing tellurium from the silver-containing material to remove tellurium.

[0028] The present invention has at least the following beneficial effects:

[0029] The present invention provides a method for removing tellurium from a silver-containing material. The silver-containing material is mixed with soda ash and anhydrous sodium tetraborate, and reacted at a first preset temperature to perform slag smelting to obtain a reaction product, wherein the first preset temperature is 1050° C.-1150° C., and the mass fraction ratio of the silver-containing material, soda ash and anhydrous sodium tetraborate is (9-11):(0.9-1.1):(2.8-3.1); after the reaction is complete, the reaction product is filtered to obtain a silver ingot, so that the qualified rate of the electrolytic silver ingot is significantly improved, and after the tellurium is removed by the method, the tellurium content in the silver-containing material is as low as 0.0004%. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 This is a schematic diagram of an embodiment of a method for removing tellurium from a silver-containing material provided by the present invention.

[0031] The purpose, features and advantages of the present invention will be further described with reference to the accompanying drawings in conjunction with the embodiments. DETAILED DESCRIPTION

[0032] The technical solution of the present invention will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. The present invention will be described in detail below with reference to the accompanying drawings and in conjunction with the embodiments. It should be noted that the embodiments of the present invention and the features in the embodiments can be combined with each other without conflict.

[0033] In the embodiments of the present invention, the term "and / or" describes the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B may represent three situations: A exists alone, A and B exist at the same time, and B exists alone. The character " / " generally indicates that the associated objects before and after are in an "or" relationship.

[0034] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence.

[0035] In the embodiments of the present invention, the term "plurality" refers to two or more than two, and other quantifiers are similar.

[0036] In the present invention, unless otherwise specified, the directional words used, such as "up, down, top, bottom", usually refer to the directions shown in the drawings, or to the components themselves in the vertical, perpendicular or gravity directions; similarly, for ease of understanding and description, "inside and outside" refer to the inside and outside relative to the outline of each component itself, but the above-mentioned directional words are not used to limit the present invention.

[0037] In order to make the purpose, technical scheme and advantages of the embodiments of the present invention clearer, the embodiments of the present invention will be described in detail below in conjunction with the accompanying drawings. However, it can be understood by those skilled in the art that in the embodiments of the present invention, many technical details are proposed in order to enable the reader to better understand the present invention. However, even without these technical details and various changes and modifications based on the following embodiments, the technical scheme claimed in the present invention can also be implemented. The division of the following embodiments is for the convenience of description and should not constitute any limitation on the specific implementation of the present invention. The various embodiments can be combined and referenced with each other under the premise of no contradiction.

[0038] The present invention provides a method for removing tellurium from a silver-containing material. The method for removing tellurium from a silver-containing material comprises:

[0039] Step S100, pre-treating the silver-containing material to remove impurities.

[0040] It should be understood that pre-treatment of the silver-containing material can remove surface impurities and oil stains.

[0041] Step S200, mixing the silver-containing material with soda ash and anhydrous sodium tetraborate, reacting at a first preset temperature to perform slag smelting to obtain a reaction product, wherein the first preset temperature is 1050° C.-1150° C., and the mass ratio of the silver-containing material, soda ash and anhydrous sodium tetraborate is (9-11): (0.9-1.1): (2.8-3.1).

[0042] It should be noted that the reaction between tellurium, soda ash and anhydrous sodium tetraborate at high temperature is complex, and the specific reaction products and reaction degree are affected by many factors, such as the ratio of reactants, reaction time, and the material of the reaction container.

[0043] The present invention mixes the silver-containing material, soda ash and anhydrous sodium tetraborate together, and the mass ratio of the silver-containing material, soda ash and anhydrous sodium tetraborate is (9-11): (0.9-1.1): (2.8-3.1), and the reaction temperature is 1050° C.-1150° C. In this way, the tellurium content in the silver-containing material can be as low as 0.00035%, which completely meets the standard of less than 0.008%.

[0044] More specifically, step S200 includes the following chemical reaction: anhydrous sodium tetraborate interacts with tellurium in the silver-containing material at a first preset temperature in an alkaline environment to generate a tellurium-containing compound.

[0045] More specifically, boron in sodium tetraborate combines with tellurium at a first predetermined temperature to form borotellurate;

[0046] The soda ash reacts with the tellurium at a first predetermined temperature to form a volatile telluride or tellurate.

[0047] The reaction of tellurium, soda ash and anhydrous sodium tetraborate is a relatively complex chemical process, and the ratio of each reactant and the reaction temperature have a great influence on the reaction. Specifically, the reaction mechanism and the product may vary greatly depending on the ratio of the reactants and the reaction temperature. In the present invention, especially when the reaction temperature is 1100°C and the mass ratio of the silver-containing material, soda ash and anhydrous sodium tetraborate is 10:1:3, the tellurium content in the silver-containing material is as low as 0.00035%, that is, the removal effect of tellurium in the silver-containing material is better.

[0048] In other embodiments, after the silver-containing material is mixed with soda ash and anhydrous sodium tetraborate, the reaction is carried out at the first stage temperature for a first time, wherein the first time is 30 minutes to 50 minutes, and the first stage temperature is 900° C. to 950° C.; after the first stage is completed, the reaction is carried out at the second stage temperature for a second time, wherein the second time is 50 minutes to 70 minutes, and the second stage temperature is 1100° C. to 1150° C. More specifically, the first time is 40 minutes, and the first stage temperature is 940° C.; the second time is 60 minutes, and the first stage temperature is 1100° C.

[0049] The process is divided into two stages. The first stage uses 900℃-950℃ to remove most of the tellurium in the silver-containing material. The second stage uses a high temperature of 1100℃-1150℃. At this time, the remaining tellurium in the silver-containing material is quickly removed. This can avoid the long-term high temperature environment affecting the silver in the silver-containing material and ensure the removal effect of tellurium in the silver-containing material.

[0050] Step S300, after the reaction is complete, filtering the reaction product to obtain a silver ingot.

[0051] Step S400, placing the obtained silver ingot into a centrifuge to remove the residual filtrate; soaking and washing the silver ingot after removing the residual filtrate in warm water at a second preset temperature, wherein the second preset temperature is 75°C-80°C.

[0052] The present invention provides a method for removing tellurium from a silver-containing material. The silver-containing material is mixed with soda ash and anhydrous sodium tetraborate, and reacted at a first preset temperature to perform slag smelting to obtain a reaction product, wherein the first preset temperature is 1050° C.-1150° C., and the mass fraction ratio of the silver-containing material, soda ash and anhydrous sodium tetraborate is (9-11):(0.9-1.1):(2.8-3.1); after the reaction is complete, the reaction product is filtered to obtain a silver ingot, so that the qualified rate of the electrolytic silver ingot is significantly improved, and after the tellurium is removed by the method, the tellurium content in the silver-containing material is as low as 0.0004%.

[0053] In order to verify the beneficial effects of the solutions provided by the present invention, examples and comparative examples are used for comparative explanation.

[0054] Example 1

[0055] S1, mixing 1 kg of silver-containing material with 100 g of soda ash and 300 g of anhydrous sodium tetraborate, reacting at 1100° C. for slag smelting to obtain a reaction product;

[0056] S2, after the reaction is complete, the reaction product is filtered to obtain a silver ingot.

[0057] Example 2

[0058] S1, 1 kg of silver-containing material is mixed with 100 g of soda ash and 300 g of anhydrous sodium tetraborate, and reacted at 950° C. for 50 min to perform slag smelting; after the first stage is completed, reacted at 1100° C.-1150° C. for 70 min to perform slag smelting to obtain a reaction product;

[0059] S2, after the reaction is complete, the reaction product is filtered to obtain a silver ingot.

[0060] Comparative Example 1

[0061] S1, mixing 1 kg of silver-containing material with 400 g of silicon dioxide, reacting and smelting at 1100° C. to obtain a reaction product;

[0062] S2, after the reaction is complete, the reaction product is filtered to obtain a silver ingot.

[0063] Comparative Example 2

[0064] S1, mixing 1 kg of silver-containing material with 400 g of anhydrous sodium tetraborate, reacting and smelting at 1100° C. to obtain a reaction product;

[0065] S2, after the reaction is complete, the reaction product is filtered to obtain a silver ingot.

[0066] Comparative Example 3

[0067] S1, mixing 1 kg of silver-containing material with 100 g of soda ash and 300 g of potassium nitrate, reacting at 1100° C. for slag smelting to obtain a reaction product;

[0068] S2, after the reaction is complete, the reaction product is filtered to obtain a silver ingot.

[0069] Table 1 Example and Comparative Example 1

[0070] plan Tellurium content in silver ingot / (%) Example 1 100g soda ash + 300g anhydrous sodium tetraborate 0.00035 Example 2 100g soda ash + 300g anhydrous sodium tetraborate 0.0004 Comparative Example 1 400g silicon dioxide 0.029 Comparative Example 2 400g anhydrous sodium tetraborate 0.014 Comparative Example 3 100g soda ash + 300g potassium nitrate 0.012

[0071] It can be seen from Table 1 that the tellurium removal rate in the silver-containing material is relatively high by adopting the solution provided by the present invention, and the tellurium content in the silver-containing material after removal is as low as 0.0035%.

[0072] The present invention also provides a silver-containing material, wherein the silver-containing material adopts the above-mentioned method for removing tellurium from the silver-containing material to remove tellurium.

[0073] Obviously, the embodiments described above are only some embodiments of the present invention, rather than all embodiments. Based on the embodiments of the present invention, ordinary technicians in this field can make other different forms of changes or modifications without creative work, which should fall within the scope of protection of the present invention.

Claims

1. A method for removing tellurium from a silver-containing material, characterized in that: include: Mixing the silver-containing material with soda ash and anhydrous sodium tetraborate, reacting at a first preset temperature to perform slag smelting to obtain a reaction product, wherein the first preset temperature is 1050° C.-1150° C., and the mass fraction ratio of the silver-containing material, soda ash and anhydrous sodium tetraborate is (9-11): (0.9-1.1): (2.8-3.1); After the reaction is complete, the reaction product is filtered to obtain a silver ingot.

2. The method for removing tellurium from a silver-containing material according to claim 1, characterized in that: The step of mixing the silver-containing material with soda ash and anhydrous sodium tetraborate and reacting at a first preset temperature to perform slag smelting to obtain a reaction product includes the following chemical reactions: In an alkaline environment at a first preset temperature, anhydrous sodium tetraborate interacts with tellurium in the silver-containing material to generate a tellurium-containing compound.

3. The method for removing tellurium from a silver-containing material according to claim 2, characterized in that: The step of mixing the silver-containing material with soda ash and anhydrous sodium tetraborate and reacting at a first preset temperature to perform slag smelting to obtain a reaction product includes the following chemical reactions: The boron in the sodium tetraborate combines with the tellurium at a first predetermined temperature to form borotellurate; The soda ash reacts with the tellurium at a first predetermined temperature to form a volatile telluride or tellurate.

4. The method for removing tellurium from a silver-containing material according to claim 1, wherein: The silver-containing material is mixed with soda ash and anhydrous sodium tetraborate, and reacted at a first preset temperature to perform slag smelting to obtain a reaction product, including: After mixing the silver-containing material with soda ash and anhydrous sodium tetraborate, reacting at a first stage temperature for a first time, wherein the first time is 30 minutes to 50 minutes and the first stage temperature is 900° C. to 950° C.; After the first stage is completed, the reaction is carried out for a second time at the second stage temperature, wherein the second time is 50 min-70 min and the second stage temperature is 1100° C.-1150° C.

5. The method for removing tellurium from a silver-containing material according to claim 1, wherein: The first duration is 40 minutes, and the first stage temperature is 940°C; The second duration is 60 minutes, and the temperature of the first stage is 1100°C.

6. The method for removing tellurium from a silver-containing material according to claim 1, characterized in that: The first preset temperature is 1100°C.

7. The method for removing tellurium from a silver-containing material according to claim 1, characterized in that: The mass ratio of the silver-containing material, soda ash and anhydrous sodium tetraborate is 10:1:

3.

8. The method for removing tellurium from a silver-containing material according to claim 1, characterized in that: Before the step of mixing the silver-containing material with soda ash and anhydrous sodium tetraborate, reacting at a first preset temperature to perform slag smelting, and obtaining a reaction product, the removal method further comprises: The silver-containing material is pretreated to remove impurities.

9. The method for removing tellurium from a silver-containing material according to claim 1, characterized in that: After the reaction is complete, filtering the reaction product to obtain a silver ingot, the method further comprises: The obtained silver ingots are placed in a centrifuge and the residual filtrate is removed; The silver ingot after removing the residual filtrate is immersed and washed in warm water at a second preset temperature, and the second preset temperature is 75°C-80°C.

10. A silver-containing material, characterized in that: The silver-containing material is treated by removing tellurium from the silver-containing material using the method for removing tellurium from the silver-containing material as described in any one of claims 1 to 9.

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