A method and apparatus for extracting tellurium from a tellurium-containing material

Abstract

This invention discloses a method and apparatus for extracting tellurium from tellurium-containing materials, comprising the steps of: mixing a sulfur-containing leaching agent with the tellurium-containing material to obtain a mixed slurry; subjecting the mixed slurry to cyclone electrolysis to obtain an anodic precipitate and a cathode product; and purifying the cathode product to obtain cathode tellurium. This invention combines selective leaching and electrowinning recovery of metallic tellurium into a single process, and utilizes the synergistic oxidation of anodic electro-oxidation and oxygen generation during electrolysis to destroy the difficult-to-leach elemental and alloy components in the tellurium-containing material, achieving one-step selective and efficient separation of tellurium-containing materials and preparation of high-purity tellurium products. By employing cyclone electrolysis to prepare cathode tellurium, this invention avoids the adverse effects of slow solution flow leading to reduced current efficiency and increased concentration polarization in traditional tellurium electrolysis, shortens the tellurium electrolysis cycle, and reduces the required concentration of impurity elements in the electrolyte, offering advantages such as high selectivity, high current density, and high product purity.

Description

Technical Field

[0001] This invention relates to the field of metallurgical technology, and in particular to a method and apparatus for extracting tellurium from tellurium-containing materials. Background Technology

[0002] Tellurium-containing materials produced during copper / lead / bismuth smelting are currently the main raw materials for tellurium extraction, accounting for over 90%. Due to varying processing techniques among different companies, tellurium-containing materials are diverse in type, complex in phase, and exhibit significant fluctuations in valuable metal content. Currently, methods for recovering tellurium from tellurium-containing materials mainly include alkaline leaching, pressurized alkaline leaching, acid leaching, pressurized acid leaching, and copper powder replacement. Among these, alkaline leaching is the primary method used by major copper and lead smelting companies nationwide. It utilizes sodium hydroxide to leach sodium tellurite and tellurium dioxide from tellurium slag into a solution. Through purification, neutralization and precipitation of tellurium, alkaline dissolution to form a solution, and electrolysis, tellurium ingots (99.99%) are obtained. This method is mature and stable, and produces high-quality products. However, it suffers from significant drawbacks, including poor adaptability to raw materials (good adaptability to tellurium-containing materials mainly composed of Na2TeO3, but poor treatment effect on telluride, elemental tellurium, and insoluble tellurates), a long process flow, and low tellurium recovery rate (60-70%). In recent years, researchers have used alkaline sulfidation leaching to separate and recover tellurium from tellurium-containing materials, achieving relatively ideal results. Patent document CN104762471A discloses a method for enhanced leaching of tellurium slag. Two or three of sodium sulfide, sodium sulfite, and sodium thiosulfate are prepared into a solution. Tellurium slag is added to the solution at a certain liquid-to-solid ratio. Nitrogen gas is introduced as a protective atmosphere. Under high temperature and pressure, insoluble substances such as MeTeO3 and MeTeO4 are converted into soluble Na2TeO3, and heavy metal ions in the solution precipitate as MeS, which enters the leaching residue. Finally, vacuum filtration is used to achieve solid-liquid separation. This method requires leaching tellurium under high temperature and pressure, resulting in high energy consumption, complex and dangerous operation, and high production costs. Patent document CN106636661A discloses a method for selectively separating and recovering tellurium from tellurium slag. The tellurium slag is added to a sodium sulfide solution, stirred, and leached. Sodium sulfite is then added to the resulting leachate for reduction to obtain crude tellurium. While this method offers good separation efficiency, high selectivity, and a simple process, it suffers from poor raw material adaptability. Patent document CN114920208A discloses a method for efficiently separating tellurium or tellurium selenium from tellurium-containing materials. The tellurium-containing material is added to an alkaline sulfide system solution composed of sodium sulfide, sodium hydroxide, and sublimed sulfur for leaching. This achieves efficient separation and extraction of valuable metals such as tellurium and selenium, while heavy metal ions such as copper, lead, and bismuth are enriched in the leaching residue, resulting in good selective extraction. However, this method has low production efficiency, a lengthy process, and a large wastewater treatment volume.

[0003] Slurry electrolysis effectively integrates mineral leaching and metal ion deposition, enabling simultaneous ore leaching and metal electrolytic deposition in a single device, while also providing some solution purification capabilities. Slurry electrolysis is characterized by its short process flow and low energy consumption, making it widely used in the extraction of primary minerals such as sulfide ores. However, there are aspects of slurry electrolysis technology that require further improvement and optimization. These mainly manifest in the following areas: a slurry depletion zone can occur during electrolysis, where the slurry concentration near the anode is too low, leading to uneven reaction and significant loss of valuable metals; a target metal ion depletion zone can also appear near the cathode, resulting in high impurity content in the deposited metal and preventing the acquisition of high-purity metals; and the leaching reaction rate in slurry electrolysis also needs further improvement.

[0004] Therefore, existing technologies still need to be improved and developed. Summary of the Invention

[0005] In view of the shortcomings of the prior art, the purpose of the present invention is to provide a method and apparatus for extracting tellurium from tellurium-containing materials, which aims to solve the problems of low current efficiency and large concentration polarization when extracting tellurium from tellurium-containing materials.

[0006] The technical solution adopted by the present invention to solve the above-mentioned technical problems is as follows:

[0007] A method for extracting tellurium from tellurium-containing materials, comprising the steps of:

[0008] Provide tellurium-containing materials and sulfur-containing leaching agents;

[0009] The sulfur-containing leaching agent is mixed with the tellurium-containing material to obtain a mixed slurry;

[0010] The mixed slurry was subjected to cyclone electrolysis to obtain anodic precipitate and cathode product;

[0011] The cathode product is purified to obtain cathode tellurium, thus realizing the extraction of tellurium from tellurium-containing materials.

[0012] The method for extracting tellurium from tellurium-containing materials, wherein the sulfur-containing leaching agent is selected from one or more of sodium sulfide, sodium hydroxide, and sublimed sulfur.

[0013] The method for extracting tellurium from tellurium-containing materials, wherein the mass-to-volume ratio of the tellurium-containing material to the sulfur-containing leaching agent is 1 g: (3-6) ml, and the excess coefficient of the sulfur-containing leaching agent is 3-5.

[0014] The method for extracting tellurium from tellurium-containing materials, wherein the feed rate of the mixed slurry is 0.3 to 3.0 L / min.

[0015] The method for extracting tellurium from tellurium-containing materials, wherein the parameters of the cyclone electrolysis are: temperature of 50–80°C, and cathode current density of 50–100 A / m. 2 The electrolysis time is 1.5 to 3 hours.

[0016] The method for extracting tellurium from tellurium-containing materials, wherein the purification process specifically comprises: washing the cathode product with oxalic acid solution at a predetermined temperature, followed by water washing and drying.

[0017] An apparatus for extracting tellurium from tellurium-containing materials, comprising a slurry feeding system and a cyclone electrolysis system;

[0018] The slurry feeding system includes a slurry tank and a start-up pump; the cyclone electrolysis system includes a cyclone electrolysis cell, an anolyte circulation tank and a catholyte circulation tank connected to the cyclone electrolysis cell via pipelines, a first centrifugal pump, a second centrifugal pump, and a DC regulated power supply electrically connected to the cyclone electrolysis cell.

[0019] The apparatus for extracting tellurium from tellurium-containing materials includes a cyclone electrolytic cell comprising an anode tube with a first inlet and a first outlet respectively disposed at both ends of the anode tube, and a cathode tube concentrically disposed with a second inlet and a second outlet respectively disposed at both ends of the cathode tube.

[0020] The apparatus for extracting tellurium from tellurium-containing materials includes a diaphragm in the cyclone electrolysis cell for separating the cathode tube from the anode tube.

[0021] The apparatus for extracting tellurium from tellurium-containing materials includes a stirring paddle installed in the slurry tank; the slurry tank is connected to the cyclone electrolysis cell via a pipeline.

[0022] Beneficial Effects: This invention discloses a method and apparatus for extracting tellurium from tellurium-containing materials. It combines selective leaching and high-purity preparation of metallic tellurium, utilizing the synergistic oxidation effect of anodic oxidation and generated oxygen during electrolysis to destroy the difficult-to-leach elemental and alloy components in the tellurium-containing materials. This achieves one-step selective and efficient leaching of tellurium-containing materials to prepare high-purity tellurium products. It reduces the purification and impurity removal processes in traditional tellurium production, shortens the production cycle, and results in low wastewater generation, a closed-loop process, and minimal emissions of waste gas, wastewater, and solid waste, making it environmentally friendly. The method employs a rotary vortex... The tellurium cathode preparation method utilizes a circulating pump to achieve forced convection through high-speed electrolyte flow, improving the mass transfer process at the cathode surface. This allows consumed thiotellurate ions to be rapidly replenished to the cathode surface, increasing the ion concentration in the cathode diffusion layer. This effectively avoids the adverse effects of slow solution flow during traditional tellurium electrolysis, such as reduced current efficiency and increased concentration polarization. It also shortens the tellurium electrolysis cycle and reduces the required concentration of impurity elements in the electrolyte. The method offers advantages such as high selectivity, high current density, and high product purity. Attached Figure Description

[0023] Figure 1 This is a flowchart of a preferred embodiment of a method for extracting tellurium from tellurium-containing materials provided by the present invention.

[0024] Figure 2 This is a schematic diagram of the cyclone electrolysis system according to an embodiment of the present invention.

[0025] Figure 3 This is a schematic diagram of the vortex electrolytic cell structure according to an embodiment of the present invention.

[0026] Figure 4 This is the XRD pattern of the anodic precipitation in Example 1 of the present invention.

[0027] Figure 5 This is a SEM image of the cathode tellurium in Embodiment 1 of the present invention.

[0028] Figure 6 This is a SEM image of the cathode tellurium in Embodiment 2 of the present invention.

[0029] Figure 7 This is a SEM image of the cathode tellurium in Embodiment 3 of the present invention.

[0030] Reference numerals: 10 cyclone electrolytic cell, 11 anode tube, 111 first inlet, 112 first outlet, 12 cathode tube, 121 second inlet, 122 second outlet, 13 diaphragm, 14 wire, 20 anode liquid circulation tank, 30 cathode liquid circulation tank, 40 first centrifugal pump, 50 second centrifugal pump, 60 DC regulated power supply, 70 first end, 80 second end. Detailed Implementation

[0031] This invention provides a method and apparatus for extracting tellurium from tellurium-containing materials. To make the objectives, technical solutions, and effects of this invention clearer and more explicit, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only for explaining the invention and are not intended to limit the invention.

[0032] Those skilled in the art will understand that, unless specifically stated otherwise, the singular forms “a,” “an,” “the,” and “the” used herein may also include the plural forms. It should be further understood that the term “comprising” as used in this specification means the presence of the stated features, integers, steps, operations, elements, and / or components, but does not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof. Those skilled in the art will understand that, unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. It should also be understood that terms such as those defined in general dictionaries should be understood to have the meaning consistent with their meaning in the context of the prior art and should not be interpreted in an idealized or overly formal sense unless specifically defined as herein.

[0033] The invention will be further explained below with reference to the accompanying drawings and the description of the embodiments.

[0034] This invention provides a method for extracting tellurium from tellurium-containing materials, see [link to relevant documentation]. Figure 1 It includes the following steps:

[0035] S10. Provide tellurium-containing materials and sulfur-containing leaching agents;

[0036] S20. The sulfur-containing leaching agent is mixed with the tellurium-containing material to obtain a mixed slurry;

[0037] S30. The mixed slurry is subjected to cyclone electrolysis. A cyclone electrolysis cell is used. The mixed slurry is added to the anode chamber and the sodium hydroxide solution is added to the cathode chamber. The electrolysis reaction is carried out for a period of time to obtain the anode precipitate and the cathode product.

[0038] S40. The cathode product is purified to obtain cathode tellurium, thereby realizing the extraction of tellurium from tellurium-containing materials.

[0039] Specifically, this invention combines selective leaching and high-purity preparation of metallic tellurium into one process. It utilizes the synergistic oxidation effect of anodic oxidation and generated oxygen during electrolysis to destroy the difficult-to-leach elemental and alloy components in tellurium-containing materials, achieving one-step selective and efficient leaching of tellurium-containing materials and preparation of high-purity tellurium products. This reduces the purification and impurity removal processes in traditional tellurium production, shortens the production cycle, and results in low wastewater generation, a closed-loop process, and minimal emissions of waste gas, wastewater, and solid waste, making it environmentally friendly. The invention employs a cyclone electrolysis method to prepare cathode tellurium. Forced convection is achieved through the high-speed flow of the electrolyte under the action of a circulating pump, improving the mass transfer process on the cathode surface. This allows the consumed thiotellurate ions to be rapidly replenished to the cathode surface, increasing the ion concentration in the cathode diffusion layer. This effectively avoids the adverse effects of slow solution flow during traditional tellurium electrolysis, such as reduced current efficiency and increased concentration polarization, shortening the tellurium electrolysis cycle and reducing the required concentration of impurity elements in the electrolyte. It offers multiple advantages, including high selectivity, high current density, and high product purity.

[0040] The principle of this invention lies in utilizing the affinity between sulfur (S) and tetrahydropalmatine (Te) to transform Te in insoluble or sparingly soluble CuTe, TeO2, Na2TeO3, and Na2TeO4 into highly soluble TeS3. 2- Or TeS4 2- The ions are removed, while Cu remains in the anode mud as sulfides. The ions enter the cathode chamber through the anion exchange membrane and are electrochemically reduced on the cathode surface to generate cathode tellurium, thus realizing the integration of anode electrochemical oxidation leaching and cathode electrodeposition reduction recovery.

[0041] The main reactions occurring in the anode chamber are the oxidation of tellurium in copper telluride and the sulfidation transformation of sodium tellurate. At the same time, an oxygen evolution reaction will also occur, and the evolved oxygen can also enhance the oxidative leaching of copper telluride. The specific reactions are shown in equations (1)-(8) below.

[0042] Na2TeO3 + 3S 2- + 3H₂O = 2Na + +TeS3 2- + 6OH - (1)

[0043] Na2TeO4 + 4S 2- + 4H₂O = 2Na + +TeS4 2- + 8OH - (2)

[0044] CuTe + ​​4S 2- -6e - = TeS3 2- + 6Na + + CuS↓ (3)

[0045] CuTe + ​​5S 2- -8e - = TeS4 2- + 8Na + + CuS↓ (4)

[0046] TeO2 + 3S 2- + 2H2O = TeS3 2- + 4OH - (5)

[0047] 4OH - - 4e - = 2H2O + O2↑ (6)

[0048] CuTe + ​​4S 2- + 1.5O2 + 3H2O = TeS3 2- + 6OH - + CuS↓ (7)

[0049] CuTe + ​​5S 2- + 2O2 + 4H2O = TeS4 2- + 8OH - + CuS↓ (8)

[0050] The main reaction in the cathode chamber is the reduction and deposition of thiotellurate ions, accompanied by partial hydrogen side reactions. The electrolyte flows at high speed under the action of the circulating pump, which can effectively convect mass transfer and suppress concentration polarization. The main chemical reactions that occur are shown in equations (9)-(11):

[0051] TeS3 2- + 4e - = 3S 2- + Te↓ (9)

[0052] TeS4 2- + 6e - = 4S 2- + Te↓ (10)

[0053] 2H2O+2e - =H2↑ + 2OH - (11)

[0054] Specifically, a cyclone electrolytic cell is used. The mixed slurry is added to the anode chamber, and the sodium hydroxide solution is added to the cathode chamber. After electrolysis for a period of time, the anode precipitate and cathode product are obtained. The anode and cathode chambers are separated by anion exchange membranes, allowing only anions to pass through. This effectively inhibits the influence of anode mud and some metal cations dissolved in the anode on the cathode reaction, improves the purity of cathode tellurium, and also plays a certain role in purifying the electrolyte. After electrowinning, the electrolyte in the cathode chamber can be recycled as leachate.

[0055] In some embodiments, the sulfur-containing leaching agent is selected from one or more of sodium sulfide, sodium hydroxide, and sublimed sulfur.

[0056] In some embodiments, the mass-to-volume ratio of the tellurium-containing material to the sulfur-containing leaching agent is 1 g:(3-6) ml, and the excess coefficient of the sulfur-containing leaching agent is (based on the conversion of all Te in the raw material to TeS3). 2- The total is 3 to 5.

[0057] In some embodiments, the feed rate of the mixed slurry is 0.3 to 3.0 L / min.

[0058] In some embodiments, the parameters of the swirl electrolysis are: temperature of 50–80°C and cathode current density of 50–100 A / m. 2 The electrolysis time is 1.5 to 3 hours.

[0059] In some embodiments, the purification process specifically involves washing, rinsing, and drying the cathode product with oxalic acid solution at a predetermined temperature to remove residual alkaline impurities such as sodium hydroxide, sodium sulfide, and sodium sulfite from the surface.

[0060] In some embodiments, the concentration of the oxalic acid solution is 0.08 mol / L, the mass-to-volume ratio of the cathode product to the oxalic acid solution is 1 g: (3-6) mL, the predetermined temperature is 70-90°C, and the cleaning time range is 1-8 h.

[0061] The present invention also provides an apparatus for extracting tellurium from tellurium-containing materials, which consists of a slurry feeding system and a cyclone electrolysis system;

[0062] The slurry delivery system includes a slurry tank and a start-up pump; see [link / reference] Figure 2 The cyclone electrolysis system includes a cyclone electrolysis cell 10, an anolyte circulation tank 20, a catholyte circulation tank 30, a first centrifugal pump 40, a second centrifugal pump 50, and a DC regulated power supply 60 electrically connected to the cyclone electrolysis cell 10 via pipes.

[0063] In some embodiments, a first end 70 and a second end 80 are respectively provided at both ends of the cyclone electrolysis cell 10.

[0064] Specifically, a pneumatic pump can cause the slurry to enter the cyclone electrolysis system at a certain speed. During the electrolysis process, tellurium ions and copper sulfide precipitates are generated at the anode. Tellurium ions are electrolyzed at the cathode. The cathode products are then boiled in oxalic acid solution, washed with water, and dried to obtain the cathode tellurium.

[0065] In some implementations, see Figure 3 The cyclone electrolysis cell 10 includes an anode tube 11, a first liquid inlet 111 and a first liquid outlet 112 respectively disposed at both ends of the anode tube 11, and a cathode tube 12 concentrically disposed with the anode tube 11, a second liquid inlet 121 and a second liquid outlet 122 respectively disposed at both ends of the cathode tube 12.

[0066] Specifically, both the first end 70 and the second end 80 are sealed with O-rings to the cyclone electrolysis cell 10; the first inlet 111 and the second inlet 121 are respectively connected to the second end 80, and the first outlet 112 and the second outlet 122 are respectively connected to the first end 70. In use, the first centrifugal pump 40 pumps the anolyte from the anolyte circulation tank 20 into the anode tube 11 through the first inlet 111, and the reacted anolyte returns to the anolyte circulation tank 20 through the first outlet 112; the second centrifugal pump 50 pumps the catholyte from the catholyte circulation tank 30 into the cathode tube 12 through the second inlet 121, and the reacted catholyte returns to the catholyte circulation tank 30 through the second outlet 122.

[0067] Optionally, the cathode tube 12 is the cathode of the swirl electrolysis system and is the main part of the electrolysis device. It is made of titanium and has a diameter of 10cm and a height of 36cm.

[0068] In some embodiments, a starter plate is also disposed on the cathode tube 12, which is attached to the cathode tube 12 in a tubular form and has an area of ​​0.04 m². 2 During electrolysis, metal ions are mainly deposited on the starting electrode. After electrolysis, the starting electrode and the metal are removed from the cathode tube 12.

[0069] In some embodiments, a wire 14 is provided at one end of the cathode tube 12 and the anode tube 11, respectively. The wire is an insulated busbar and is used for connecting the anode and cathode of the electrolytic cell to the anode and cathode of the DC regulated power supply 60.

[0070] Optionally, the anode tube 11 is the anode of the cyclone electrolysis system. The anode tube 11 is made of titanium-coated electrode and is located in the center of the electrolytic cell. It is thicker in the middle and thinner at both ends. The middle part is cylindrical with a diameter of 2.5 cm and a height of 36 cm. The two ends are in contact with the end to achieve the purpose of fixation.

[0071] Furthermore, the cathode tube 12 and the anode tube 11 use a pair of concentric tubes instead of planar electrodes. Under high current density conditions, the mass transfer process is greatly enhanced by the high-speed swirling flow of the target solution, overcoming the problem of "mineral slurry depletion zone" that is easy to generate in traditional electrolysis processes, and realizing the efficient transfer of target metal ions. Compared with existing diaphragm electrolysis, the present invention uses a swirling flow method for the electro-extraction process. Compared with swirling flow electrolysis, the present invention utilizes the electro-oxidation capacity of the anode to leach tellurium-containing materials.

[0072] This invention utilizes the oxidation effect at the anode during electrolysis to oxidize and leach elemental or alloy components in tellurium-containing materials, innovatively applying cyclone electrolysis to the treatment of tellurium-containing materials. Compared to slurry electrolysis, this invention uses cyclone electrolysis to reduce the deposited catholyte, achieving efficient extraction of metallic tellurium from tellurium-containing materials under conventional conditions, i.e., lower temperature and pressure. Furthermore, copper ions in the tellurium-containing material precipitate in the anode region as copper sulfide, making it a highly efficient and clean process. In addition, compared to slurry electrolysis, the cyclone method employed in this invention can significantly eliminate concentration polarization of metal ions in the catholyte in the cathode region, resulting in high-purity cathode tellurium.

[0073] In some embodiments, a diaphragm 13 is provided in the cyclone electrolysis cell 10 to separate the cathode tube 12 from the anode tube 11, and to separate the slurry and electrolyte. After electrolysis, the slurry returns to the slurry tank for circulating electrolysis. The diaphragm 13 can prevent anode mud from passing through, thus avoiding the scouring of the cathode surface by anode mud during the cyclone leaching process, ensuring the quality of the cathode deposit, and facilitating the collection of anode mud. Preferably, the diaphragm 13 is an anion exchange membrane.

[0074] In some embodiments, a stirring paddle is provided in the slurry tank to maintain a uniform mixing state of the slurry; the slurry tank is connected to the cyclone electrolysis cell 10 via a pipe.

[0075] Specifically, the working principle of the device for extracting tellurium from tellurium-containing materials according to the present invention is as follows: Under the synergistic oxidation effect in the anode zone, the poorly soluble tellurium in the tellurium-containing material reacts with the sulfur-containing leaching agent to form soluble sodium thiotellurate, while heavy metal ions such as copper in the tellurium-containing material come into contact with sulfur ions in the solution and precipitate in the anode zone. Therefore, selective separation of tellurium in the tellurium-containing material can be achieved in one step in the anode zone, so that copper is enriched in the leaching residue. At the same time, in the cathode zone, the tellurium-containing leaching solution has a low impurity content due to the purification effect of sodium sulfide. Therefore, under high current density conditions, elemental tellurium can be directly prepared by cyclone electrolysis.

[0076] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are merely some embodiments of the present invention, not all embodiments, and are only for illustrating the present invention and are not intended to limit the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Unless otherwise specified, all reagents and raw materials used in the present invention are commercially available goods or products that can be prepared by known methods.

[0077] Example 1

[0078] A method for extracting tellurium from tellurium-containing materials, comprising the steps of:

[0079] S10. Provide tellurium-containing material and sulfur-containing leaching agent, wherein the sulfur-containing leaching agent is sodium sulfide, and the tellurium-containing material comprises, by mass percentage: Te 21.71wt%, Cu 43.25wt%, S 3.23wt%, and Cl 1.29wt%.

[0080] S20. Grind the tellurium-containing material into a particle size of less than 74μm to obtain mineral powder; mix the sulfur-containing leaching agent and mineral powder evenly at a liquid-to-solid volume / mass ratio of 6ml:1g to obtain a mixed slurry;

[0081] S30. The mixed slurry is placed in a slurry tank and fed into the cyclone electrolysis system at a feed rate of 1.0 L / min using a pneumatic pump, and then subjected to electrolysis at 70°C and 80 A / m. 2 The cathode current density is used for swirl electrolysis. The slurry after electrolysis is reintroduced into the slurry tank and the cycle is repeated for step S30. Electrolysis is carried out for 2 hours to obtain anode precipitate and cathode product.

[0082] S40. The cathode product is boiled and washed with 0.08 mol / L oxalic acid solution for 8 hours. After boiling and washing, it is rinsed with deionized water and dried to obtain cathode tellurium, thereby realizing the extraction of tellurium from tellurium-containing materials.

[0083] After electrolysis in this embodiment, the XRD pattern of the obtained anolyte is shown below. Figure 4 The tellurium recovery rate reached 98.33%, copper leaching was almost nonexistent, and the purity of the cathode tellurium reached 99.95%. The resulting SEM image of the cathode tellurium is shown below. Figure 5 .

[0084] Example 2

[0085] A method for extracting tellurium from tellurium-containing materials, comprising the steps of:

[0086] S10. Provide tellurium-containing material and sulfur-containing leaching agent, wherein the sulfur-containing leaching agent is sodium sulfide, and the tellurium-containing material comprises, by mass percentage: Te 2.03wt%, Pb 31.49wt%, Sb 7.42wt%, Ba 10.03wt%, Bi 2.49wt%, S 6.45wt%, and C 5.87wt%.

[0087] S20. Grind the tellurium-containing material into a particle size of less than 74μm to obtain mineral powder; mix the sulfur-containing leaching agent and mineral powder evenly at a liquid-to-solid volume / mass ratio of 5ml:1g to obtain a mixed slurry;

[0088] S30. The mixed slurry is placed in a slurry tank and fed into the cyclone electrolysis system at a feed rate of 2.0 L / min using a pneumatic pump, and then subjected to electrolysis at 70°C and 90 A / m. 2 The cathode current density is used for swirl electrolysis. The slurry after electrolysis is reintroduced into the slurry tank and the cycle is repeated for step S30. Electrolysis is carried out for 2 hours to obtain anode precipitate and cathode product.

[0089] S40. The cathode product is boiled and washed with 0.08 mol / L oxalic acid solution for 8 hours. After boiling and washing, it is rinsed with deionized water and dried to obtain cathode tellurium, thereby realizing the extraction of tellurium from tellurium-containing materials.

[0090] In this embodiment, after electrolysis, the tellurium recovery rate reached 96.45%, and the purity of the cathode tellurium reached 99.67%. The SEM image of the obtained cathode tellurium is shown below. Figure 6 .

[0091] Example 3

[0092] A method for extracting tellurium from tellurium-containing materials, comprising the steps of:

[0093] S10. Provide tellurium-containing material and sulfur-containing leaching agent, wherein the sulfur-containing leaching agent is sodium sulfide, and the tellurium-containing material comprises, by mass percentage: Te 15.48wt%, Se 14.64wt%, Cu 1.15wt%, Ag 2.36wt%, Pb 8.80wt%, Na 21.67wt%;

[0094] S20. Grind the tellurium-containing material into a particle size of less than 74μm to obtain mineral powder; mix the sulfur-containing leaching agent and mineral powder evenly at a liquid-to-solid volume / mass ratio of 5ml:1g to obtain a mixed slurry;

[0095] S30. The mixed slurry is placed in a slurry tank and fed into the cyclone electrolysis system at a feed rate of 2.5 L / min using a pneumatic pump, and then subjected to electrolysis at 80°C and 60 A / m. 2 The cathode current density is used for swirl electrolysis. The slurry after electrolysis is reintroduced into the slurry tank and the cycle is repeated for step S30. Electrolysis is carried out for 2 hours to obtain anode precipitate and cathode product.

[0096] S40. The cathode product is boiled and washed with 0.08 mol / L oxalic acid solution for 8 hours. After boiling and washing, it is rinsed with deionized water and dried to obtain cathode tellurium, thereby realizing the extraction of tellurium from tellurium-containing materials.

[0097] In this embodiment, after electrolysis, the tellurium recovery rate reached 95.29%, and the purity of the cathode tellurium reached 99.42%. The SEM image of the obtained cathode tellurium is shown below. Figure 7 .

[0098] In summary, this invention discloses a method and apparatus for extracting tellurium from tellurium-containing materials, comprising the steps of: providing tellurium-containing materials and a sulfur-containing leaching agent; mixing the sulfur-containing leaching agent with the tellurium-containing materials to obtain a mixed slurry; subjecting the mixed slurry to cyclone electrolysis to obtain an anode precipitate and a cathode product; and purifying the cathode product to obtain cathode tellurium, thereby realizing the extraction of tellurium from tellurium-containing materials. This invention combines selective leaching and high-purity preparation of metallic tellurium into a single process. It utilizes the synergistic oxidation effect of anodic oxidation and generated oxygen during electrolysis to destroy the difficult-to-leach elemental and alloy components in tellurium-containing materials, achieving one-step selective and efficient leaching of tellurium-containing materials and the preparation of high-purity tellurium products. This reduces the purification and impurity removal processes required in traditional tellurium production, shortens the production cycle, and results in low wastewater generation, a closed-loop process, and minimal emissions, making it environmentally friendly. The invention employs a cyclone electrolysis method to prepare cathode tellurium. Forced convection is achieved through the high-speed flow of the electrolyte under the action of a circulating pump, improving the mass transfer process on the cathode surface. This allows consumed thiotellurate ions to be rapidly replenished to the cathode surface, increasing the ion concentration in the cathode diffusion layer. This effectively avoids the adverse effects of slow solution flow during traditional tellurium electrolysis, such as reduced current efficiency and increased concentration polarization. It shortens the tellurium electrolysis cycle, reduces the required concentration of impurity elements in the electrolyte, and offers multiple advantages including high selectivity, high current density, and high product purity.

[0099] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or make equivalent substitutions for some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for extracting tellurium from tellurium-containing materials, characterized in that, Including the following steps: S10. Provide tellurium-containing material and sulfur-containing leaching agent, wherein the sulfur-containing leaching agent is sodium sulfide, and the tellurium-containing material comprises, by mass percentage: Te 21.71wt%, Cu 43.25wt%, S 3.23wt%, Cl 1.29wt%; S20. Grind the tellurium-containing material into a particle size of less than 74μm to obtain mineral powder; mix the sulfur-containing leaching agent and mineral powder evenly at a liquid-to-solid volume / mass ratio of 6mL:1g to obtain a mixed slurry; S30. The mixed slurry is placed in a slurry tank and fed into the cyclone electrolysis system at a feed rate of 1.0 L / min using a pneumatic pump, and then subjected to electrolysis at 70°C and 80 A / m. 2 The cathode current density is used for swirl electrolysis. The slurry after electrolysis is reintroduced into the slurry tank and the cycle is repeated for step S30. Electrolysis is carried out for 2 hours to obtain anode precipitate and cathode product. S40. The cathode product is boiled and washed with 0.08 mol / L oxalic acid solution for 8 hours. After boiling and washing, it is rinsed with deionized water and dried to obtain cathode tellurium, thereby realizing the extraction of tellurium from tellurium-containing materials.

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