A method for producing electrolytic copper from copper-containing sludge

Abstract

The present application relates to the technical field of slag wool processing application, and a method for producing electrolytic copper by using copper-containing sludge, comprising the following steps: step one, sludge pretreatment; step two, leaching; step three, purification; step four, electrolytic deposition; and step five, waste gas and waste liquid treatment; the purity of the electrolytic copper produced by the present application reaches 99.95% or above, realizing the resource utilization of the copper-containing sludge, reducing the production cost of the electrolytic copper, avoiding environmental pollution, and having significant environmental and economic benefits, and being suitable for large-scale popularization and application.

Description

Technical Field

[0001] This invention relates to the field of electrolytic copper application technology, specifically a method for producing electrolytic copper using copper-containing sludge. Background Technology

[0002] Copper-containing sludge is solid waste generated by industries such as electroplating, printed circuit board manufacturing, and mining. It contains high concentrations of copper and other heavy metals (such as nickel, zinc, and lead). Traditional treatment methods include landfilling, incineration, and chemical leaching, but these methods suffer from resource waste, environmental pollution, and high costs. Electrolytic copper is an important material widely used in electrical, electronic, and construction fields. Its traditional production process mainly relies on the smelting of copper concentrate, which is costly and highly dependent on ore resources. Therefore, we propose a method for producing electrolytic copper using copper-containing sludge. Summary of the Invention

[0003] To achieve the above objectives, the present invention provides the following technical solution: a method for producing electrolytic copper using copper-containing sludge, comprising the following steps: Step 1: sludge pretreatment; Step 2: leaching; Step 3: purification; Step 4: electrolytic deposition; Step 5: waste gas and waste liquid treatment; Step 1: Dewater the copper-containing sludge to reduce its moisture content to below 30%, dry the dewatered sludge to further reduce the moisture content to below 5%, and crush and screen the dried sludge to obtain particles with a particle size of less than 2 mm. Step 2: Mix the pretreated sludge with a leaching agent (such as sulfuric acid or ammonia) in a certain proportion and carry out the leaching reaction at room temperature to 80°C to convert the copper in the sludge into soluble copper ions. The amount of leaching agent is 1-3 times the mass of sludge, and the leaching time is 2-6 hours. After leaching, copper-containing leachate is obtained by solid-liquid separation. Step 3: Purify the copper-containing leachate to remove impurities such as iron, nickel, and zinc. Use chemical precipitation or solvent extraction for purification. Add sodium sulfide or sodium hydroxide to adjust the pH value, so that the impurity ions can precipitate and be removed by filtration. The copper ion concentration in the purified solution should reach 20-50 g / L. Step 4: Use the purified copper-containing solution as the electrolyte, and use a stainless steel or titanium plate as the cathode and a lead alloy plate as the anode for electrolytic deposition. The current density is 200-400A / m², the cell voltage is 2-3V, and the electrolysis temperature is 40-60℃. During the electrolysis process, copper ions are reduced to high-purity electrolytic copper on the cathode. The cathode plate is periodically removed to peel off the electrolytic copper. Step 5: The waste gas generated during the leaching and purification process is treated by an absorption tower and discharged after meeting the standards. The waste liquid generated during the electrolysis process is returned to the leaching process for recycling, achieving zero waste liquid discharge.

[0004] Preferably, in step one, 1000 kg of copper-containing sludge is taken, and after dehydration, the moisture content is reduced to 25%. After drying, the moisture content is 4%, and the sludge is crushed and screened to obtain particles with a particle size of less than 2 mm.

[0005] Preferably, in step two, the pretreated sludge is mixed with twice the mass of sulfuric acid solution (10% concentration), and aluminum is leached at 60°C for 4 hours. After leaching, solid-liquid separation is performed using a filter press to obtain a copper-containing leachate.

[0006] Preferably, in step three, sodium sulfide solution is added to the copper-containing leaching solution to adjust the pH value to 3.5, so that impurities such as iron and nickel can form precipitates and be removed by filtration, and the copper ion concentration in the purified solution is 35 g / L.

[0007] Preferably, in step four, the purified solution is used as the electrolyte, and a stainless steel cathode and a lead alloy anode are used. Electrolytic deposition is carried out at a current density of 300 A / m², a cell voltage of 2.5 V, and an electrolysis temperature of 50 °C. After 8 hours of electrolysis, the cathode plate is removed and the electrolytic copper is stripped off to obtain high-purity electrolytic copper.

[0008] Preferably, the waste gas generated during the leaching process in step five is treated by an absorption tower and discharged in compliance with standards, while the electrolytic waste liquid is returned to the leaching process for recycling.

[0009] This invention provides a method for producing electrolytic copper using copper-containing sludge. It has the following beneficial effects: This invention converts copper-containing sludge into high-purity electrolytic copper, realizing the resource utilization of solid waste. Through purification and waste gas treatment, heavy metal pollution and harmful gas emissions are avoided. Using copper-containing sludge as raw material reduces the production cost of electrolytic copper. By optimizing process parameters, the purity of the produced electrolytic copper reaches over 99.95%. This process not only realizes the resource utilization of copper-containing sludge and reduces the production cost of electrolytic copper, but also avoids environmental pollution. This process has significant environmental and economic benefits and is suitable for large-scale promotion and application. Attached Figure Description

[0010] Figure 1 This is a flowchart of the preparation method of the present invention. Detailed Implementation

[0011] 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 only some embodiments of the present invention, and not all embodiments. 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.

[0012] like Figure 1As shown, the present invention provides a technical solution: a method for producing electrolytic copper using copper-containing sludge, comprising the following steps: Step 1: sludge pretreatment; Step 2: leaching; Step 3: purification; Step 4: electrolytic deposition; Step 5: waste gas and waste liquid treatment; Step 1: Dewater the copper-containing sludge to reduce its moisture content to below 30%, dry the dewatered sludge to further reduce the moisture content to below 5%, and crush and screen the dried sludge to obtain particles with a particle size of less than 2 mm. Step 2: Mix the pretreated sludge with a leaching agent (such as sulfuric acid or ammonia) in a certain proportion and carry out the leaching reaction at room temperature to 80°C to convert the copper in the sludge into soluble copper ions. The amount of leaching agent is 1-3 times the mass of sludge, and the leaching time is 2-6 hours. After leaching, copper-containing leachate is obtained by solid-liquid separation. Step 3: Purify the copper-containing leachate to remove impurities such as iron, nickel, and zinc. Use chemical precipitation or solvent extraction for purification. Add sodium sulfide or sodium hydroxide to adjust the pH value, so that the impurity ions can precipitate and be removed by filtration. The copper ion concentration in the purified solution should reach 20-50 g / L. Step 4: Use the purified copper-containing solution as the electrolyte, and use a stainless steel or titanium plate as the cathode and a lead alloy plate as the anode for electrolytic deposition. The current density is 200-400A / m², the cell voltage is 2-3V, and the electrolysis temperature is 40-60℃. During the electrolysis process, copper ions are reduced to high-purity electrolytic copper on the cathode. The cathode plate is periodically removed to peel off the electrolytic copper. Step 5: The waste gas generated during the leaching and purification process is treated by an absorption tower and discharged after meeting the standards. The waste liquid generated during the electrolysis process is returned to the leaching process for recycling, achieving zero waste liquid discharge.

[0013] Preferably, in step one, 1000 kg of copper-containing sludge is taken, and after dehydration, the moisture content is reduced to 25%. After drying, the moisture content is 4%, and the sludge is crushed and screened to obtain particles with a particle size of less than 2 mm.

[0014] Preferably, in step two, the pretreated sludge is mixed with twice the mass of sulfuric acid solution (10% concentration), and aluminum is leached at 60°C for 4 hours. After leaching, solid-liquid separation is performed using a filter press to obtain a copper-containing leachate.

[0015] Preferably, in step three, sodium sulfide solution is added to the copper-containing leaching solution to adjust the pH value to 3.5, so that impurities such as iron and nickel can form precipitates and be removed by filtration, and the copper ion concentration in the purified solution is 35 g / L.

[0016] Preferably, in step four, the purified solution is used as the electrolyte, and a stainless steel cathode and a lead alloy anode are used. Electrolytic deposition is carried out at a current density of 300 A / m², a cell voltage of 2.5 V, and an electrolysis temperature of 50 °C. After 8 hours of electrolysis, the cathode plate is removed and the electrolytic copper is stripped off to obtain high-purity electrolytic copper.

[0017] Preferably, the waste gas generated during the leaching process in step five is treated by an absorption tower and discharged in compliance with standards, while the electrolytic waste liquid is returned to the leaching process for recycling.

[0018] This invention extracts copper from copper-containing sludge through pretreatment, leaching, purification, and electrolysis to produce high-purity electrolytic copper. The copper in the sludge is converted into soluble copper ions through acid leaching or ammonia leaching. After purification to remove impurities, high-purity electrolytic copper is obtained through electrolytic deposition.

[0019] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0020] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method for producing electrolytic copper using copper-containing sludge, characterized in that, Includes the following steps: Step 1: Sludge pretreatment; Step 2: Leaching; Step 3: Purification; Step 4: Electrolytic deposition; Step 5: Waste gas and waste liquid treatment; Step 1: Dewater the copper-containing sludge to reduce its moisture content to below 30%, dry the dewatered sludge to further reduce the moisture content to below 5%, and crush and screen the dried sludge to obtain particles with a particle size of less than 2 mm. Step 2: Mix the pretreated sludge with a leaching agent (such as sulfuric acid or ammonia) in a certain proportion and carry out the leaching reaction at room temperature to 80°C to convert the copper in the sludge into soluble copper ions. The amount of leaching agent is 1-3 times the mass of sludge, and the leaching time is 2-6 hours. After leaching, copper-containing leachate is obtained by solid-liquid separation. Step 3: Purify the copper-containing leachate to remove impurities such as iron, nickel, and zinc. Use chemical precipitation or solvent extraction for purification. Add sodium sulfide or sodium hydroxide to adjust the pH value, so that the impurity ions can precipitate and be removed by filtration. The copper ion concentration in the purified solution should reach 20-50 g / L. Step 4: Use the purified copper-containing solution as the electrolyte, and use a stainless steel or titanium plate as the cathode and a lead alloy plate as the anode for electrolytic deposition. The current density is 200-400A / m², the cell voltage is 2-3V, and the electrolysis temperature is 40-60℃. During the electrolysis process, copper ions are reduced to high-purity electrolytic copper on the cathode. The cathode plate is periodically removed to peel off the electrolytic copper. Step 5: The waste gas generated during the leaching and purification process is treated by an absorption tower and discharged after meeting the standards. The waste liquid generated during the electrolysis process is returned to the leaching process for recycling, achieving zero waste liquid discharge.

2. The method for producing electrolytic copper from copper-containing sludge according to claim 1, characterized in that: In step one, 1000 kg of copper-containing sludge is taken, and after dehydration, the moisture content is reduced to 25%. After drying, the moisture content is 4%, and the sludge is crushed and screened to obtain particles with a particle size of less than 2 mm.

3. The method for producing electrolytic copper from copper-containing sludge according to claim 1, characterized in that: In step two, the pretreated sludge is mixed with twice the mass of sulfuric acid solution (10% concentration), and aluminum is leached at 60°C for 4 hours. After leaching, solid-liquid separation is performed using a filter press to obtain copper-containing leachate.

4. The method for producing electrolytic copper from copper-containing sludge according to claim 1, characterized in that: In step three, sodium sulfide solution is added to the copper-containing leaching solution to adjust the pH value to 3.5, so that impurities such as iron and nickel can form precipitates and be removed by filtration. The copper ion concentration in the purified solution is 35 g / L.

5. The method for producing electrolytic copper from copper-containing sludge according to claim 1, characterized in that: In step four, the purified solution is used as the electrolyte. A stainless steel cathode and a lead alloy anode are used for electrolytic deposition at a current density of 300 A / m², a cell voltage of 2.5 V, and an electrolysis temperature of 50 °C. After 8 hours of electrolysis, the cathode plate is removed and the electrolytic copper is stripped off to obtain high-purity electrolytic copper.

6. The method for producing electrolytic copper from copper-containing sludge according to claim 1, characterized in that: The waste gas generated during the leaching process in step five is treated by an absorption tower and discharged in compliance with standards, while the electrolytic waste liquid is returned to the leaching process for recycling.

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