Device and method for efficiently removing sodium in refining process of 4N metal tellurium

Abstract

The invention discloses a device and a method for efficiently removing sodium in a 4N metal tellurium refining process. The process comprises the following steps of: performing tellurium electrodeposition on tellurium-containing oxide to produce tellurium sheets; and the tellurium sheet is subjected to microwave boiling washing, drying, automatic casting and other steps, and finally a qualified 4N metal tellurium product is produced. According to the technical scheme provided by the invention, special microwave boiling and washing equipment is adopted for boiling and washing the tellurium piece as one-time sodium removal, and the sodium removal efficiency reaches 99% or above; automatic metal tellurium casting equipment is adopted in the casting process, meanwhile, a mechanical stirring device is additionally arranged in the tellurium piece melting link, the device is made of a carbon rod, meanwhile, a curing agent is added for impurity removal, it is guaranteed that impurities in metal tellurium are effectively removed, and meanwhile the production efficiency is greatly improved. According to the device and the method, the application range is wide, special microwave equipment and automatic metal tellurium casting equipment are adopted, the problem that sodium impurities in 4N metal tellurium are not thoroughly removed is solved, meanwhile, automatic equipment is high in production efficiency, and large-scale production is easy to achieve.

Description

Technical Field

[0001] The invention belongs to the technical field of smelting equipment, and in particular relates to a device and a method for efficiently removing sodium in a 4N metal tellurium refining process. Background Art

[0002] Tellurium metal is a metalloid with a certain metallic luster. Tellurium has a high density and moderate hardness. The melting point of tellurium is 452℃ and the boiling point is 1390℃. In terms of chemical properties, tellurium has certain oxidizing and reducing properties. Tellurium burns to produce tellurium dioxide when heated in air. It can form alloys with many metals and react with some non-metals. Tellurium metal has a wide range of uses and is important in the metallurgical industry. Tellurium can be added to steel as an additive, which can significantly improve the mechanical properties of steel, improve the strength, hardness and toughness of steel, and enhance the corrosion resistance of steel and extend the service life of steel products. In the production process of copper alloys, adding an appropriate amount of tellurium can refine the grains, improve the electrical conductivity and thermal conductivity of copper alloys, and make them more suitable for the manufacture of electronic components and electrical equipment. In addition, tellurium can also form special alloys with other metal elements. These alloys have excellent performance in harsh environments such as high temperature and high pressure, and are widely used in aerospace, petrochemical and other fields. At present, the main production methods of tellurium are to extract it from anode mud of copper refining and from certain specific ores. The application fields of tellurium mainly include the electronic information field, where it is used to manufacture high-performance electronic components; in the field of new energy, it can be used in the production of solar cells to improve conversion efficiency; in the metallurgical industry, it can improve the strength and corrosion resistance of metal materials.

[0003] Most domestic tellurium production enterprises basically choose the sodium hydroxide dissolution method and the electrolytic process in the production process of tellurium. Therefore, there will be a certain amount of sodium in tellurium, and appropriate processes will be adopted to remove sodium before the finished tellurium is cast. The sodium removal process in the tellurium production process is relatively simple, and basically hot water soaking or boiling washing is used. For example, Fang Mengzhao and others from Daye Nonferrous Metals Co., Ltd. proposed a method for deep sodium removal in the process of producing 4N tellurium ingots (CN116657212A), which discloses a method for deep sodium removal in the production of 4N tellurium ingots, including tellurium electrolytic process, tellurium sheet primary boiling and washing process, tellurium sheet secondary boiling and washing process, drying process and casting process, and finally obtain the 99.99% tellurium ingot product specified in YS / T222-2010 "Tellurium Ingot". For example, Li Yanlong et al. of Northwest Institute of Mining and Metallurgy proposed a method for recovering tellurium from tellurium copper slag and preparing high-purity tellurium (CN115432672A). The present invention relates to a method for recovering tellurium from tellurium copper slag and preparing high-purity tellurium, the method comprising the following steps: grinding and crushing the dried tellurium copper slag to obtain tellurium copper slag powder; adding the tellurium copper slag powder to a sodium hydroxide solution, stirring the reaction, slowly adding sodium chlorate during the reaction, filtering after the reaction to obtain a filter residue A and a tellurium-containing filtrate; washing and filtering the filter residue A to obtain a washed filtrate; Washing residue and washing liquid; adding dilute sulfuric acid to the tellurium-containing filtrate to react and obtain crude tellurium dioxide; dissolving the crude tellurium dioxide with sodium hydroxide solution and filtering to obtain filter residue B and filtrate A; adding dilute sulfuric acid to filtrate A to react and obtain high-purity tellurium dioxide; dissolving high-purity tellurium dioxide with sodium hydroxide solution to obtain filter residue C and filtrate B; passing sulfur dioxide gas into filtrate B to control the solution reduction potential to -3.6--8.2 until the solution changes from orange-yellow to colorless, and filtering the reduced filtrate to obtain high-purity tellurium. The method for removing sodium in the tellurium production process mentioned in the above two patents adopts acid boiling and repeated washing with clean water. This method has the main disadvantage of low efficiency. When the tellurium flakes have a large particle size, the mixed sodium cannot be effectively removed. At the same time, a large amount of alkaline wastewater will be generated in the process for subsequent treatment, which increases environmental pressure. Summary of the invention

[0004] In order to solve the above problems, the present invention provides a device and method for efficiently removing sodium in a 4N metal tellurium refining process.

[0005] The technical solution of the present invention is implemented as follows: a device for efficiently removing sodium in a 4N metal tellurium refining process, comprising a boiling and washing device and an automatic casting machine, wherein the boiling and washing device comprises a microwave boiling and washing chamber, wherein a gas inlet is provided at the lower side of one end of the microwave boiling and washing chamber, an air inlet pipe connected to the gas inlet is provided at the bottom of the microwave boiling and washing chamber, a plurality of gas outlets are provided on the air inlet pipe, and the gas outlets are located above the liquid in the microwave boiling and washing chamber, a discharge port is provided at the upper side of the other end of the microwave boiling and washing chamber, a heating coil is provided in the microwave boiling and washing chamber, the heating coil is connected to a steam inlet located outside the microwave boiling and washing chamber, a clean water inlet is provided above the microwave boiling and washing chamber, and the discharge port of the microwave boiling and washing chamber is connected to a filter press pump and a filter press; Preferably, the gas introduced into the microwave cooking and cleaning chamber is nitrogen, and the nitrogen is introduced from top to bottom through the air inlet pipe and the gas outlet, so that the nitrogen and the liquid in the cooking and cleaning chamber are kept in a surging state.

[0006] Preferably, the automatic casting machine comprises a control system and a melting pot, an inverted U-shaped mechanical stirring rod is arranged in the melting pot, an outlet of the melting pot is connected to a chute, a tundish is arranged below the chute outlet, and a mold is arranged below the tundish; Preferably, the mechanical stirring rod is a graphite carbon rod; Preferably, the chute, the tundish and the mold are all provided with heating resistance wires; A method for efficiently removing sodium in a 4N metal tellurium refining process comprises the following steps: a. The tellurium-containing material is subjected to dissolution purification, sulfuric acid neutralization, calcination to remove selenium, dissolution to make liquid, and tellurium electrodeposition to obtain tellurium sheets; b. Take the tellurium flakes produced by tellurium electrowinning, crush them and place them in a microwave washing chamber, add clean water according to the solid-liquid ratio of 6:1, turn on the steam for heating, ensure that the temperature is stable at about 100°C, turn on the microwave, turn on the nitrogen to ensure that the liquid surface is surging for microwave washing, and after washing, open the filter press pump inlet valve-filter press pump-filter press machine in sequence for solid-liquid separation. After the solid-liquid separation, the tellurium is transferred to the drying equipment and the temperature is maintained at about 150°C for drying; c. The dried tellurium sheet is loaded into the melting furnace of the automatic casting machine, and the temperature is raised to 800°C for melting. After melting, mechanical stirring is started, and a curing agent is added to remove impurities until there is no solid slag on the liquid surface; d. Preheat the tundish, chute and mold of the automatic casting machine to ensure that the temperature is around 550°C. After reaching the temperature requirement, the qualified high-temperature tellurium liquid is cast through the automatic casting machine to obtain metal tellurium products.

[0007] The beneficial effects of the present invention are as follows: the production process proposed by the present invention has the significant advantages of easy operation, good environment, strong process adaptability and high efficiency, and microwaves are used to achieve efficient removal of sodium in the production process of 4N metal tellurium. At the same time, an automatic casting machine is configured to increase mechanical stirring of graphite carbon rods to ensure effective removal of impurities, thereby having high economic benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 is a process flow chart of the present invention; Figure 2 It is a schematic structural diagram of the microwave cooking and washing device of the present invention; Figure 3 It is a schematic structural diagram of the automatic casting machine of the present invention.

[0009] Parts description: 1. Microwave cooking and washing chamber, 2. Gas inlet, 3. Heating coil, 4. Clean water inlet, 5. Discharge port, 6. Filter press pump, 7. Filter press, 8. Mechanical stirring rod, 9. Melting furnace, 10. Chute, 11. Tundish, 12. Mold, 13. Control system, 14. Air inlet pipe, 15. Gas outlet, 16. Steam inlet, 17. Automatic casting machine. DETAILED DESCRIPTION

[0010] In order to better understand and implement the invention, the present invention is further described below in conjunction with the accompanying drawings: A device for efficiently removing sodium in the process of 4N metal tellurium refining, comprising a microwave cooking chamber 1 and an automatic casting machine 17, wherein a gas inlet 2 is provided at the lower side of one end of the microwave cooking chamber, an air inlet pipe 14 connected to the gas inlet 2 is provided at the bottom of the microwave cooking chamber 1, and a plurality of gas outlets 15 are provided on the air inlet pipe 14, and the gas outlets 15 are located above the liquid in the microwave cooking chamber 1, and the gas introduced into the microwave cooking chamber 1 is nitrogen, which is introduced from top to bottom through the air inlet pipe 14 and the gas outlet 15, so that the nitrogen and the liquid in the cooking chamber are kept in a surging state. The role of nitrogen is to achieve that the solution in the microwave cooking chamber is kept in a surging state and combined with microwaves to better exert the washing effect, and secondly, nitrogen is used to provide a gas protection for the overall atmosphere to prevent the element form in the material from changing during the microwave cooking process. A discharge port 5 is provided on the upper side of the other end of the microwave cooking and washing chamber 1. A heating coil 3 is provided in the microwave cooking and washing chamber 1. The heating coil 3 is connected to a steam inlet 16 located outside the microwave cooking and washing chamber 1. Steam heating is used during use to ensure that the cooking and washing temperature is maintained at about 100°C, and the microwave is combined to better exert the washing effect. A clean water inlet 4 is provided above the microwave cooking and washing chamber 1. The discharge port 5 of the microwave cooking and washing chamber 1 is connected to a filter press pump 6 and a filter press 7.

[0011] The automatic casting machine 17 includes a control system 13 and a melting pot 9. An inverted U-shaped mechanical stirring rod 8 is provided in the melting pot 9. The mechanical stirring rod 8 is a graphite carbon rod. The use of the graphite carbon rod has the following effects: first, the graphite carbon rod has good chemical stability and high temperature resistance at high temperatures, and is not easy to react with the components in the tellurium ingot; second, it can effectively reduce the bubbles and looseness inside the tellurium ingot, thereby improving the density and quality of the tellurium ingot. The outlet of the melting pot 9 is connected to the chute 10. A tundish 11 is provided below the outlet of the chute 10. A mold 12 is provided below the tundish 11. The chute 10, the tundish 11 and the mold 12 are all provided with heating resistance wires. They are preheated before casting to ensure that no splashing occurs during casting.

[0012] A method for efficiently removing sodium in a 4N metal tellurium refining process comprises the following steps: a Tellurium-containing materials are subjected to dissolution purification, sulfuric acid neutralization, calcination to remove selenium, dissolution to make liquid, and tellurium electrowinning to obtain tellurium sheets: Dissolution purification: Liquid-solid ratio: 6:1, pH value: 9-10, reaction temperature: 85-95℃, reaction time: 1h; Sulfuric acid neutralization: 98% sulfuric acid and water in a 1:1 ratio, reaction temperature: 85-95°C, pH value 5-6, reaction time: 1h; Calcination to remove selenium: Temperature: 480-600℃, time 6-8h; Dissolution and liquid preparation: Liquid-solid ratio (3-5): 1, reaction temperature: 85-95°C, amount of caustic soda added: 0.4-0.6g / gTeO2, analytical pure sodium sulfide nonahydrate: 100g-150g / 100L, reaction time 2-4h; Telluride Electrodeposition: Electrolytic solution Te content: 150-240g / L, current density: 40A-60A / m2, cell voltage: 12-32V; b. Take the tellurium flakes produced by tellurium electrowinning, crush them and weigh 100kg, place them in a microwave cooking and washing device, add 600kg of clean water according to the solid-liquid ratio of 6:1, turn on the steam for heating to ensure that the temperature is stable at about 100°C, turn on the microwave, turn on the nitrogen to ensure that the liquid surface is surging for microwave washing, and after washing, open the filter press pump inlet valve-filter press pump-filter press machine in sequence for solid-liquid separation; after solid-liquid separation, the tellurium is transferred to the drying equipment and the temperature is maintained at about 150°C for drying; c. The dried tellurium sheet is loaded into the melting furnace of the automatic casting machine, and the temperature is raised to 800°C for melting. After melting, mechanical stirring is started, and borax is added for impurity removal until there is no solid slag on the liquid surface; d. Preheat the tundish, chute and mold of the casting machine to ensure that the temperature is around 550°C. After reaching the temperature requirement, the qualified high-temperature tellurium liquid is cast through an automatic casting machine to obtain a metal tellurium product.

[0013]

[0014]

[0015] By comparing with the 4N metal tellurium standard, the main problem of tellurium sheets produced by tellurium electrowinning before sodium removal is that the Na content far exceeds the standard, while the remaining elements are also close to the standard line.

[0016] Comparative Example 1: The following steps are adopted: Before sodium removal, the tellurium sheet is subjected to sodium removal cycles by soaking washing, boiling washing and microwave boiling washing, and the results of the comparison of the content of each element are shown in the table below.

[0017]

[0018]

[0019] Through the above data analysis, the sodium removal method using microwave boiling and washing is compared with the conventional soaking and boiling methods. The effect is very obvious in terms of duration and reduction of the grade of each element. The sodium removal rate of the microwave boiling and washing method reaches 99.14%.

[0020] Comparative Example 2: The following steps are adopted: After sodium is removed, the tellurium sheet is removed by a non-stirring method and a graphite carbon rod mechanical stirring method. The cycle and the content of each element are compared, as shown in the table below.

[0021]

[0022] Through the above data analysis, the use of graphite carbon rod mechanical stirring to remove impurities can significantly reduce the time of impurity removal compared with no stirring.

[0023] Comparative Example 3: The following steps are adopted: the production cycle of casting metal tellurium using a metal tellurium automatic casting machine is compared with that of casting metal tellurium using a conventional medium frequency furnace, as shown in the table below.

[0024]

[0025] Through the above data analysis, the use of metal tellurium automatic casting machine can significantly improve the production efficiency of tellurium ingots and has the promotion value of large-scale production.

Claims

1. A device for efficiently removing sodium in the process of 4N metal tellurium refining, characterized in that The invention comprises a cooking and washing device and an automatic casting machine (17), wherein the cooking and washing device comprises a microwave cooking and washing chamber (1), wherein a gas inlet (2) is provided at the lower side of one end of the microwave cooking and washing chamber, an air inlet pipe (14) connected to the gas inlet (2) is provided at the bottom of the microwave cooking and washing chamber (1), a plurality of gas outlets (15) are provided on the air inlet pipe (14), and the gas outlets (15) are located above the liquid in the microwave cooking and washing chamber (1), and a discharge port (5) is provided at the upper side of the other end of the microwave cooking and washing chamber (1), a heating coil (3) is provided in the microwave cooking and washing chamber (1), and the heating coil (3) is connected to a steam inlet (16) located outside the microwave cooking and washing chamber (1), a clean water inlet (4) is provided above the microwave cooking and washing chamber (1), and the discharge port (5) of the microwave cooking and washing chamber (1) is connected to a filter press pump (6) and a filter press (7).

2. The device for efficiently removing sodium in the 4N tellurium metal refining process according to claim 1, characterized in that The gas introduced into the microwave cooking and cleaning chamber (1) is nitrogen, which is introduced from top to bottom through the air inlet pipe (14) and the gas outlet (15), so that the nitrogen and the liquid in the cooking and cleaning chamber are kept in a surging state.

3. A device for efficiently removing sodium in a 4N tellurium metal refining process as claimed in claim 1 or 2, characterized in that The automatic casting machine (17) comprises a control system (13) and a melting pot (9), wherein an inverted U-shaped mechanical stirring rod (8) is provided in the melting pot (9), an outlet of the melting pot (9) is connected to a chute (10), a tundish (11) is provided below the outlet of the chute (10), and a mold (12) is provided below the tundish (11).

4. A device for efficiently removing sodium in a 4N tellurium metal refining process as claimed in claim 3, characterized in that The mechanical stirring rod (8) is a graphite carbon rod.

5. A device for efficiently removing sodium in a 4N tellurium metal refining process as claimed in claim 3 or 4, characterized in that The chute (10), the tundish (11) and the mould (12) are all provided with heating resistance wires.

6. A method for removing sodium using the high-efficiency sodium removal device in the 4N tellurium metal refining process as claimed in claim 1, 2, 3, 4 or 5, characterized in that The following steps are involved: a. The tellurium-containing material is subjected to dissolution purification, sulfuric acid neutralization, calcination to remove selenium, dissolution to make liquid, and tellurium electrodeposition to obtain tellurium sheets; b. Take the tellurium flakes produced by tellurium electrowinning, crush them and place them in a microwave washing chamber, add clean water according to the solid-liquid ratio of 6:1, turn on the steam for heating, ensure that the temperature is stable at about 100°C, turn on the microwave, turn on the nitrogen to ensure that the liquid surface is surging for microwave washing, and after washing, open the filter press pump inlet valve-filter press pump-filter press machine in sequence for solid-liquid separation. After the solid-liquid separation, the tellurium is transferred to the drying equipment and the temperature is maintained at about 150°C for drying; c. The dried tellurium sheet is loaded into the melting furnace of the automatic casting machine, and the temperature is raised to 800°C for melting. After melting, mechanical stirring is started, and a curing agent is added to remove impurities until there is no solid slag on the liquid surface; d. Preheat the tundish, chute and mold of the automatic casting machine to ensure that the temperature is around 550°C. After reaching the temperature requirement, the qualified high-temperature tellurium liquid is cast through the automatic casting machine to obtain metal tellurium products.

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