Method for targeted separation of copper and tellurium in copper telluride slag through microwave synergistic ultrasonic external field

Abstract

The invention relates to a method for separating copper and tellurium in copper telluride slag in a targeted manner through a microwave-assisted ultrasonic external field, and belongs to the technical field of hydrometallurgy. The copper telluride slag is subjected to low-power-density microwave drying to evaporate water to obtain dry copper telluride slag, and the evaporated water is collected to prepare a sodium hydroxide-hydrogen peroxide mixed solution; the method comprises the following steps: uniformly mixing dry copper telluride slag with concentrated sulfuric acid, performing high-power-density microwave sulfating roasting to obtain a roasted product and sulfur dioxide tail gas, cooling the roasted product to room temperature, crushing and screening; sodium hydroxide and hydrogen peroxide are added into water to prepare a sodium hydroxide-hydrogen peroxide mixed solution, and the sulfur dioxide tail gas is absorbed and purified by the sodium hydroxide-hydrogen peroxide mixed solution to prepare acid; and adding the roasted product into water, uniformly mixing, carrying out ultrasonic enhanced water leaching, and carrying out solid-liquid separation to obtain a copper sulfate filtrate and tellurium oxide filter residues. The method is short in treatment time and simple in technological process, and copper and tellurium in the copper telluride slag can be efficiently separated.

Description

Technical Field

[0001] This invention relates to a method for targeted separation of copper and tellurium in copper telluride slag using microwave-assisted ultrasonic external field, belonging to the field of hydrometallurgical technology. Background Technology

[0002] The telluride copper slag produced during the copper smelting anode slime treatment process contains valuable metals such as copper, tellurium, selenium, gold, and silver. Heavy metals, if not treated promptly, can harm the environment and human health. From an industrial production perspective, telluride copper slag is a secondary resource with extremely high recycling value. From both social and economic perspectives, the recycling and utilization of telluride copper slag is becoming increasingly important.

[0003] The treatment processes for copper telluride slag are divided into pyrometallurgical and hydrometallurgical methods. Pyrometallurgical recovery uses a sulfation roasting-sodium hydroxide leaching process to leach tellurium from the copper telluride slag. The roasting process generates harmful fumes and results in the loss of valuable materials as dust, requiring sophisticated dust recovery and corrosive gas purification equipment. Hydrometallurgical processes are currently the most widely used, offering advantages in metal dispersion, energy consumption, and environmental protection. Oxidative-alkali leaching and oxidative-acid leaching involve leaching copper telluride slag in the presence of an oxidant to dissolve copper and tellurium, followed by solvent extraction or adsorption to separate Cu-Te. While effective, these methods require multiple extraction / back-extraction or adsorption / desorption steps to achieve high separation efficiency, leading to a lengthy recovery process. Therefore, a new, highly efficient method for recovering copper telluride slag is needed to address the problems of low leaching rates, fumes pollution, and lengthy recovery processes in current methods. Summary of the Invention

[0004] To address the problems of low leaching rates, flue gas pollution, lengthy recovery processes, and high energy consumption in existing copper telluride slag treatment processes, this invention proposes a method for targeted separation of copper and tellurium in copper telluride slag using a microwave-assisted ultrasonic field. The method involves heating the copper telluride slag at low microwave power density to evaporate moisture, collecting the water vapor, and preparing a tail gas absorbent. Then, the copper telluride slag is sulfated and roasted at high power density, and the sulfur dioxide tail gas is purified by absorption and washing to produce acid. The roasted product is crushed and subjected to ultrasonic water leaching, followed by filtration to obtain copper sulfate filtrate and tellurium oxide residue. The solid material is dried to obtain tellurium oxide. This method offers short processing time, a simple process flow, and efficient separation of copper and tellurium from copper telluride slag.

[0005] A method for targeted separation of copper and tellurium in copper telluride slag (main phase Cu2Te) using microwave-assisted ultrasonic field, the specific steps of which are as follows: (1) Copper telluride slag is dried by microwave drying with low power density to obtain dry copper telluride slag. The evaporated water is collected to prepare a sodium hydroxide-hydrogen peroxide mixture. The microwave power density is 10~40kW / m³. 3 ; (2) The dry copper telluride slag is mixed evenly with concentrated sulfuric acid and then roasted by microwave sulfation with high power density to obtain roasting products and sulfur dioxide tail gas. The roasting products are cooled to room temperature and crushed and screened. The microwave power density is 60~90kW / m³. 3 The reaction equation for copper telluride and concentrated sulfuric acid during microwave sulfation roasting is as follows: Cu2Te+6H2SO4=2CuSO4+TeO2+4SO2+6H2O (3) Sodium hydroxide and hydrogen peroxide are added to water to prepare a sodium hydroxide-hydrogen peroxide mixture. The sulfur dioxide tail gas in step (2) is purified by the sodium hydroxide-hydrogen peroxide mixture and then used to produce acid. (4) The roasted product is added to water and mixed evenly, then subjected to ultrasonic-enhanced water immersion, and solid-liquid separation to obtain copper sulfate filtrate and tellurium oxide residue.

[0006] Preferably, the water content of the copper telluride slag in step (1) is 40~50wt.%, and the anhydrous copper telluride slag contains 30~50wt% copper and 30~40wt% tellurium.

[0007] Preferably, the molar ratio of concentrated sulfuric acid to dry tellurized copper slag in step (2) is 4~7:1.

[0008] Preferably, the microwave sulfation roasting temperature in step (2) is 300~550℃ and the time is 15~75min.

[0009] Preferably, in step (3), the sodium hydroxide-hydrogen peroxide mixture has a sodium hydroxide concentration of 0.77~1.28 mol / L and a hydrogen peroxide concentration of 0.60~0.90 mol / L.

[0010] Preferably, in step (4), the liquid-to-solid ratio of water to calcined product (mL:g) is 2~6:1, the ultrasonic power is 50~300W, the water immersion temperature is 25~45℃, and the time is 3~11min.

[0011] The beneficial effects of this invention are: (1) The present invention does not require pretreatment of copper telluride slag, and microwave drying and microwave sulfation roasting can be carried out in the same system, resulting in low processing cost and high reaction efficiency. (2) The copper telluride slag of the present invention has a strong wave absorption capacity, the reaction phase transformation is faster, the process safety factor is high, and it can effectively avoid the situation of incomplete reaction and local sintering caused by traditional roasting. (3) The method of the present invention has the advantages of short process, low energy consumption, strong selectivity and high efficiency, and solves problems such as low leaching rate and long recovery process. Attached Figure Description

[0012] Figure 1 This is a process flow diagram of the present invention. Detailed Implementation

[0013] The present invention will be further described in detail below with reference to specific embodiments, but the scope of protection of the present invention is not limited to the content described.

[0014] Example 1: The composition of the copper telluride slag mineral in this example is shown in Table 1. Table 1. Composition and content of copper telluride slag

[0015] A method for targeted separation of copper and tellurium in copper telluride slag using microwave-assisted ultrasonic external field (see...) Figure 1 The specific steps are as follows: (1) Copper telluride slag with low power density (10kW / m³) 3 Microwave drying and evaporation of moisture yields dry tellurized copper slag, and the evaporated moisture is collected to prepare a sodium hydroxide-hydrogen peroxide mixture. (2) Mix 10g of dry copper telluride slag with concentrated sulfuric acid (98% by mass) until homogeneous, and then process it through a high power density (60kW / m³). 3 Microwave sulfation roasting yielded roasting products and sulfur dioxide tail gas. The roasting products were cooled to room temperature and crushed and sieved. The molar ratio of concentrated sulfuric acid to dry copper telluride slag was 4:1. The microwave sulfation roasting temperature was 300℃ and the time was 15 min. The reaction formula between copper telluride and concentrated sulfuric acid during the microwave sulfation roasting process is as follows: Cu2Te+6H2SO4=2CuSO4+TeO2+4SO2+6H2O (3) Sodium hydroxide and hydrogen peroxide are added to water to prepare a sodium hydroxide-hydrogen peroxide mixture. The sulfur dioxide tail gas in step (2) is purified by absorption of the sodium hydroxide-hydrogen peroxide mixture and then used to produce acid. The sodium hydroxide-hydrogen peroxide mixture has a sodium hydroxide concentration of 0.77 mol / L and a hydrogen peroxide concentration of 0.60 mol / L. (4) The calcined product is added to water and mixed evenly. The mixture is then subjected to ultrasonic enhancement and water immersion for 3 minutes at 30°C. Solid-liquid separation is performed to obtain copper sulfate filtrate and 4.086 g tellurium oxide residue. The liquid-solid ratio of water to calcined product is 2:1 mL:g, the ultrasonic power is 50 W, and the ultrasonic frequency is 20 kHz. The copper leaching rate in this embodiment was found to be 62.53%.

[0016] Example 2: The composition of the copper telluride slag mineral in this example is the same as that in Example 1; A method for targeted separation of copper and tellurium in copper telluride slag using microwave-assisted ultrasonic external field (see...) Figure 1 The specific steps are as follows: (1) Copper telluride slag with low power density (20kW / m³) 3Microwave drying and evaporation of moisture yields dry tellurized copper slag, and the evaporated moisture is collected to prepare a sodium hydroxide-hydrogen peroxide mixture. (2) Mix 10g of dry copper telluride slag with concentrated sulfuric acid (98% by mass) until homogeneous, and then process it through a high power density (70kW / m³). 3 Microwave sulfation roasting yielded roasting products and sulfur dioxide tail gas. The roasting products were cooled to room temperature and crushed and sieved. The molar ratio of concentrated sulfuric acid to dry copper telluride slag was 5:1. The microwave sulfation roasting temperature was 350℃ and the time was 30 min. The reaction formula between copper telluride and concentrated sulfuric acid during the microwave sulfation roasting process is as follows: Cu2Te+6H2SO4=2CuSO4+TeO2+4SO2+6H2O (3) Sodium hydroxide and hydrogen peroxide are added to water to prepare a sodium hydroxide-hydrogen peroxide mixture. The sulfur dioxide tail gas in step (2) is purified by absorption of the sodium hydroxide-hydrogen peroxide mixture and then used to produce acid. The sodium hydroxide-hydrogen peroxide mixture has a sodium hydroxide concentration of 0.85 mol / L and a hydrogen peroxide concentration of 0.65 mol / L. (4) The calcined product is added to water and mixed evenly. The mixture is then ultrasonically enhanced and soaked in water for 5 minutes at 35°C. Solid-liquid separation is performed to obtain copper sulfate filtrate and 3.445 g tellurium oxide residue. The liquid-solid ratio of water to calcined product is 3:1 mL:g, the ultrasonic power is 100 W, and the ultrasonic frequency is 20 kHz. The copper leaching rate in this embodiment was found to be 74.00%.

[0017] Example 3: The composition of the copper telluride slag mineral in this example is the same as that in Example 1; A method for microwave-assisted ultrasonic field-targeted separation of copper and tellurium in copper telluride slag (see...) Figure 1 The specific steps are as follows: (1) Copper telluride slag with low power density (30kW / m³) 3 Microwave drying and evaporation of moisture yields dry tellurized copper slag, and the evaporated moisture is collected to prepare a sodium hydroxide-hydrogen peroxide mixture. (2) Mix 10g of dry copper telluride slag with concentrated sulfuric acid (98% by mass) until homogeneous, and then process it through a high power density (80kW / m³). 3 Microwave sulfation roasting yielded roasting products and sulfur dioxide tail gas. The roasting products were cooled to room temperature and crushed and sieved. The molar ratio of concentrated sulfuric acid to dry copper telluride slag was 6:1. The microwave sulfation roasting temperature was 400℃ and the time was 45 min. The reaction formula between copper telluride and concentrated sulfuric acid during the microwave sulfation roasting process is as follows: Cu2Te+6H2SO4=2CuSO4+TeO2+4SO2+6H2O (3) Sodium hydroxide and hydrogen peroxide are added to water to prepare a sodium hydroxide-hydrogen peroxide mixture. The sulfur dioxide tail gas in step (2) is purified by absorption of the sodium hydroxide-hydrogen peroxide mixture and then used to produce acid. The sodium hydroxide-hydrogen peroxide mixture has a sodium hydroxide concentration of 0.90 mol / L and a hydrogen peroxide concentration of 0.70 mol / L. (4) The calcined product is added to water and mixed evenly. The mixture is then ultrasonically enhanced and soaked in water for 9 minutes at a temperature of 40°C. Solid-liquid separation is performed to obtain copper sulfate filtrate and 2.8480g tellurium oxide residue. The liquid-solid ratio of water to calcined product is 4:1 mL:g, the ultrasonic power is 200W, and the ultrasonic frequency is 20kHz. The copper leaching rate in this embodiment was found to be 96.77%.

[0018] Example 4: The composition of the copper telluride slag mineral in this example is the same as that in Example 1; A method for microwave-assisted ultrasonic field-targeted separation of copper and tellurium in copper telluride slag (see...) Figure 1 The specific steps are as follows: (1) Copper telluride slag with low power density (30kW / m³) 3 Microwave drying and evaporation of moisture yields dry tellurized copper slag, and the evaporated moisture is collected to prepare a sodium hydroxide-hydrogen peroxide mixture. (2) Mix 10g of dry copper telluride slag with concentrated sulfuric acid (98% by mass) until homogeneous, and then process it through a high power density (80kW / m³). 3 Microwave sulfation roasting yielded roasting products and sulfur dioxide tail gas. The roasting products were cooled to room temperature and crushed and sieved. The molar ratio of concentrated sulfuric acid to dry copper telluride slag was 7:1. The microwave sulfation roasting temperature was 550℃ and the time was 75 min. The reaction formula between copper telluride and concentrated sulfuric acid during the microwave sulfation roasting process is as follows: Cu2Te+6H2SO4=2CuSO4+TeO2+4SO2+6H2O (3) Sodium hydroxide and hydrogen peroxide are added to water to prepare a sodium hydroxide-hydrogen peroxide mixture. The sulfur dioxide tail gas in step (2) is purified by absorption of the sodium hydroxide-hydrogen peroxide mixture and then used to produce acid. The sodium hydroxide-hydrogen peroxide mixture has a sodium hydroxide concentration of 1.20 mol / L and a hydrogen peroxide concentration of 0.90 mol / L. (4) The calcined product was added to water and mixed evenly. The mixture was then ultrasonically enhanced and soaked in water for 11 minutes at 45°C. Solid-liquid separation was performed to obtain copper sulfate filtrate and 2.506 g tellurium oxide residue. The liquid-solid ratio of water to calcined product was 6:1 mL:g, the ultrasonic power was 300 W, and the ultrasonic frequency was 20 kHz. The copper leaching rate in this embodiment was found to be 97.42%.

[0019] Example 5: The composition of the copper telluride slag mineral in this example is the same as that in Example 1; A method for microwave-assisted ultrasonic field-targeted separation of copper and tellurium in copper telluride slag (see...) Figure 1 The specific steps are as follows: (1) Copper telluride slag with low power density (40kW / m³) 3 Microwave drying and evaporation of moisture yields dry tellurized copper slag, and the evaporated moisture is collected to prepare a sodium hydroxide-hydrogen peroxide mixture. (2) Mix 10g of dry copper telluride slag with concentrated sulfuric acid (98% by mass) until homogeneous, and then process it through a high power density (90kW / m³). 3 Microwave sulfation roasting yielded roasting products and sulfur dioxide tail gas. The roasting products were cooled to room temperature and crushed and sieved. The molar ratio of concentrated sulfuric acid to dry copper telluride slag was 6:1. The microwave sulfation roasting temperature was 350℃, and the time was 15 min. The reaction formula between copper telluride and concentrated sulfuric acid during the microwave sulfation roasting process is as follows: Cu2Te+6H2SO4=2CuSO4+TeO2+4SO2+6H2O (3) Sodium hydroxide and hydrogen peroxide are added to water to prepare a sodium hydroxide-hydrogen peroxide mixture. The sulfur dioxide tail gas in step (2) is purified by absorption of the sodium hydroxide-hydrogen peroxide mixture and then used to produce acid. The sodium hydroxide-hydrogen peroxide mixture has a sodium hydroxide concentration of 1.00 mol / L and a hydrogen peroxide concentration of 0.90 mol / L. (4) The calcined product is added to water and mixed evenly. The mixture is then subjected to ultrasonic enhancement and water immersion for 5 minutes at 25°C. Solid-liquid separation is performed to obtain copper sulfate filtrate and 2.205 g tellurium oxide residue. The liquid-solid ratio of water to calcined product is 5:1 mL:g, the ultrasonic power is 250 W, and the ultrasonic frequency is 20 kHz. The copper leaching rate in this embodiment was found to be 99.88%.

[0020] The specific embodiments of the present invention have been described in detail above. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention.

Claims

1. A method for targeted separation of copper and tellurium in copper telluride slag using microwave-assisted ultrasonic external field, characterized in that, The specific steps are as follows: (1) Copper telluride slag is dried by microwave drying with low power density to obtain dry copper telluride slag. The evaporated water is collected to prepare a sodium hydroxide-hydrogen peroxide mixture. The microwave power density is 10~40kW / m³. 3 ; (2) The dry copper telluride slag is mixed evenly with concentrated sulfuric acid and then roasted by microwave sulfation with high power density to obtain roasting products and sulfur dioxide tail gas. The roasting products are cooled to room temperature and crushed and screened. The microwave power density is 60~90kW / m³. 3 ; (3) Sodium hydroxide and hydrogen peroxide are added to water to prepare a sodium hydroxide-hydrogen peroxide mixture. The sulfur dioxide tail gas in step (2) is purified by the sodium hydroxide-hydrogen peroxide mixture and then used to produce acid. (4) The roasted product is added to water and mixed evenly, then subjected to ultrasonic-enhanced water immersion, and solid-liquid separation to obtain copper sulfate filtrate and tellurium oxide residue.

2. The method for targeted separation of copper and tellurium in copper telluride slag using microwave-assisted ultrasonic external field as described in claim 1, characterized in that: Step (1) The water content of copper telluride slag is 40~50wt., and the anhydrous copper telluride slag contains 30~50wt% copper and 30~40wt% tellurium.

3. The method for targeted separation of copper and tellurium in copper telluride slag using microwave-assisted ultrasonic external field as described in claim 1, characterized in that: Step (2) The molar ratio of concentrated sulfuric acid to dry tellurized copper slag is 4~7:

1.

4. The method for targeted separation of copper and tellurium in copper telluride slag using microwave-assisted ultrasonic external field as described in claim 1, characterized in that: Step (2) Microwave sulfation roasting temperature is 300~550℃, time is 15~75min.

5. The method for targeted separation of copper and tellurium in copper telluride slag using microwave-assisted ultrasonic external field as described in claim 1, characterized in that: In step (3), the concentration of sodium hydroxide in the sodium hydroxide-hydrogen peroxide mixture is 0.77~1.28 mol / L and the concentration of hydrogen peroxide is 0.60~0.90 mol / L.

6. The method for targeted separation of copper and tellurium in copper telluride slag using microwave-assisted ultrasonic external field as described in claim 1, characterized in that: Step (4) The liquid-solid ratio of water to calcined product is 2~6:1 mL:g, the ultrasonic power is 50~300W, the water immersion temperature is 25~45℃, and the time is 3~11min.

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