Method for enriching copper from metal smelting slag through vacuum distillation desulfurization

Abstract

The invention discloses a method for enriching copper from metal smelting slag through vacuum distillation desulfurization. The method for enriching copper from metal smelting slag through vacuum distillation desulfurization comprises the following steps that firstly, raw materials are prepared; step 2, vacuum distillation setting; step 3, vacuum distillation; step 4, condensing and collecting; 5, cooling and curing; according to the method for enriching the copper from the metal smelting slag through vacuum distillation desulfurization, the metal separation efficiency and the resource utilization rate are remarkably improved through the following technical scheme that efficient separation is achieved, specifically, step-by-step heating can be conducted in a low-pressure environment through the vacuum distillation technology, the separation conditions are accurately controlled, and the separation efficiency is improved; and different components are separated under the optimal conditions, so that the separation efficiency is improved. Copper and sulfur can be effectively separated through multi-step heating and step-by-step pressure reduction, mixing of volatile impurities is reduced, and therefore the purity of target metal is improved.

Description

Technical Field

[0001] The invention relates to a method for collecting and enriching copper, in particular to a method for vacuum distilling and desulfurizing and enriching copper from metal smelting slag, belonging to the technical field of metal smelting desulfurization and enriching copper. Background Art

[0002] A large amount of smelting slag is produced during the copper smelting process, which contains a certain amount of copper and sulfide. With the continuous development of the copper smelting industry, the treatment and recovery of copper and sulfur in smelting slag has become increasingly important. At present, the treatment methods of copper smelting slag mainly include grinding and flotation method and reduction and depletion method.

[0003] The grinding and flotation method is to crush the slowly cooled slag and then grind it to 0.074mm with a ball mill. The cuprous sulfide crystals and metallic copper particles in the slag are separated by flotation by taking advantage of the difference in surface physical properties between the slag components and the slag components. The slag after copper extraction is called copper tailings, which are mainly used for storage or as building materials. However, the grinding and flotation method has the following disadvantages:

[0004] 1. Low separation efficiency: Due to the difficulty in accurately controlling the flotation conditions, the copper recovery rate is low.

[0005] 2. Impurities mixed in: Impurities are easily mixed into the copper concentrate during the flotation process, reducing the purity of the copper.

[0006] 3. Environmental pollution: The storage of flotation reagents and tailings may cause environmental pollution.

[0007] The reduction depletion method is to use a reducing agent to reduce the metal in the slag, but this method also has many problems:

[0008] 1. High energy consumption: The reduction process requires high temperature and high energy consumption, which increases the processing cost.

[0009] 2. Complex process: The reduction process is complex, the operation is difficult, and the equipment maintenance is frequent.

[0010] 3. Low copper purity: other metal impurities are difficult to separate effectively during the reduction process, affecting the purity of copper.

[0011] Traditional methods usually use a single temperature and pressure control, and cannot optimize the separation conditions according to the different components of smelting slag, resulting in low separation efficiency, and volatile impurities are easily mixed into the target product, reducing the purity of the metal. The existing technology has obvious limitations in the smelting slag treatment process, and an efficient, low-energy consumption, and copper purity-enhancing separation method is urgently needed.

[0012] In view of the deficiencies in the prior art, the present invention proposes a method for desulfurizing and enriching copper from metal smelting slag by vacuum distillation. The method achieves optimal separation conditions for different components and improves separation efficiency through multi-step heating and gradual pressure reduction. Multi-step distillation prevents the mixing of volatile impurities, improves the purity of the target metal, reduces energy consumption, flexibly adjusts operating parameters, adapts to the processing requirements of different raw materials, and improves equipment utilization, thereby having significant technical advantages. Summary of the invention

[0013] The object of the present invention is to provide a method for desulfurizing and enriching copper from metal smelting slag by vacuum distillation, so as to solve the problems raised in the above background technology.

[0014] To achieve the above object, the present invention provides the following technical solution: a method for desulfurizing and enriching copper from metal smelting slag by vacuum distillation, wherein the steps of the method for desulfurizing and enriching copper from metal smelting slag by vacuum distillation are as follows:

[0015] Step 1: Raw material preparation, collect metal smelting slag and crush the smelting slag to uniform particle size, pre-dry at 120℃ to remove moisture;

[0016] Step 2: Vacuum distillation setup: Assemble the vacuum distillation equipment, including the distillation furnace, condenser and collection container, ensure that the vacuum system is intact and leak-free, the connections are tight, and set the vacuum degree to provide a low-pressure environment for the subsequent desulfurization process;

[0017] Step 3: Vacuum distillation: put the smelting slag into a vacuum distillation furnace, and adjust the vacuum degree in two steps: 5Pa in the first step and 2Pa in the second step. Gradually heat to 1200℃, keep for 2 hours, and perform the first step of distillation. Lower the temperature to 1050℃, keep for 2 hours, and perform the second step of distillation.

[0018] Step 4: Condensation and collection, introducing the volatile gas into the condenser, using the cooling medium cold water or nitrogen to cool the gas to a liquid state, collecting the condensed copper-enriched liquid or solid in the collection container of the condenser, and introducing the condensed gas into the sulfide absorption device, and recovering the sulfide in the condensed gas through sodium hydroxide solution or alkaline adsorbent;

[0019] Step 5: Cooling and solidification. After the distillation is completed, the high-temperature residue is quickly removed from the distillation furnace and placed in a cooling area. The temperature is quickly lowered to room temperature using an air cooling or water cooling system. The cooled residue solidifies into a block for subsequent processing and storage.

[0020] Step 6: Purification of enriched copper: preliminary screening of the collected condensate to remove impurities, the collected enriched copper liquid or solid cast into a plate and placed in an electrolytic cell as an anode, pure copper is used as a cathode, and electrolysis is carried out using a copper sulfate solution, and pure copper is precipitated at the cathode.

[0021] As a preferred technical solution of the present invention, the particle size of the smelting slag in step one is 0.5mm-1mm.

[0022] As a preferred technical solution of the present invention, in the step 2, the vacuum degree is set to 1Pa-10Pa.

[0023] As a preferred technical solution of the present invention, in the step three, the heating temperature is controlled within the range of 850°C-1200°C, and the distillation time is controlled within 2 hours-4 hours.

[0024] As a preferred technical solution of the present invention, in step 4, the temperature of the condensation system is maintained at 0°C-20°C to improve the condensation efficiency.

[0025] As a preferred technical solution of the present invention, in step 5, the electrolyte is a copper sulfate solution with a concentration of 150 g / L-250 g / L and an electrolysis current density of 100 A / m 2 -200A / m 2 , electrolysis duration: 6h-12h.

[0026] Compared with the prior art, the beneficial effects of the present invention are as follows: the method of vacuum distillation desulfurization and enrichment of copper from metal smelting slag of the present invention significantly improves the metal separation efficiency and resource utilization rate through the following technical schemes: High-efficiency separation: vacuum distillation technology can be gradually heated under low pressure environment, and the separation conditions can be accurately controlled, so that different components can be separated under their optimal conditions, thereby improving the separation efficiency. Multi-step heating and gradual pressure reduction can effectively separate copper and sulfur, reduce the mixing of volatile impurities, and thus improve the purity of the target metal; Low energy consumption: the gradual heating and step-by-step operation during the vacuum distillation process reduce the energy required for each step. Compared with the traditional high temperature and high pressure method, the thermal energy utilization efficiency is higher, and the overall energy consumption is significantly reduced; High-efficiency recovery of sulfur: the sulfide in the gas is recovered by the sulfide absorption device during the condensation process, which realizes the efficient recovery of sulfur, reduces environmental pollution, and improves the recycling rate of resources; Flexible adjustment: vacuum distillation allows flexible adjustment of operating parameters to meet the processing requirements of different raw materials. By optimizing the vacuum degree and temperature settings, various types of smelting slag can be processed, improving the adaptability and utilization rate of the equipment; reducing downtime: multi-step distillation and step-by-step heating operations reduce the downtime of the overall equipment and allow online maintenance during operation, thereby improving production efficiency and equipment stability; high purity and good consistency: vacuum distillation technology can effectively prevent the mixing of impurities during the separation process, and the copper product finally obtained has high purity and good consistency, which meets industrial standards. Through these advantages, the present invention not only improves the efficiency and economy of smelting slag treatment, but also has a positive impact on environmental protection and resource utilization. DETAILED DESCRIPTION

[0027] The technical solutions in the embodiments of the present invention are described clearly and completely. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0028] The present invention provides a method for desulfurizing and enriching copper from metal smelting slag by vacuum distillation. The method for desulfurizing and enriching copper from metal smelting slag by vacuum distillation has the following steps:

[0029] Step 1: Raw material preparation, collect metal smelting slag and crush the smelting slag to ensure uniform particle size, the smelting slag particle size is 0.5mm-1mm, and pre-dry at 120℃ to remove moisture;

[0030] Step 2: Vacuum distillation setup, assemble the vacuum distillation equipment, including the distillation furnace, condenser and collection container, ensure that the vacuum system is intact and leak-free, and the connection is tight, and set the vacuum degree to 1Pa-10Pa to provide a low-pressure environment for the subsequent desulfurization process;

[0031] Step 3: Vacuum distillation: put the smelting slag into a vacuum distillation furnace, and adjust the vacuum degree in two steps: 5Pa in the first step and 2Pa in the second step. Gradually heat to 1200℃, keep for 2 hours, and perform the first step of distillation. Lower the temperature to 1050℃, keep for 2 hours, and perform the second step of distillation.

[0032] Step 4: Condensation and collection, introducing the volatile gas into the condenser, using the cooling medium cold water or nitrogen to cool the gas to a liquid state, collecting the condensed copper-enriched liquid or solid in the collection container of the condenser, and introducing the condensed gas into the sulfide absorption device, and recovering the sulfide in the condensed gas through sodium hydroxide solution or alkaline adsorbent;

[0033] Step 5: Cooling and solidification. After the distillation is completed, the high-temperature residue is quickly removed from the distillation furnace and placed in a cooling area. The temperature is quickly lowered to room temperature using an air cooling or water cooling system. The cooled residue solidifies into a block for subsequent processing and storage.

[0034] Step 6: Purification of enriched copper: preliminary screening of the collected condensate to remove impurities, the collected enriched copper liquid or solid cast into a plate and placed in an electrolytic cell as an anode, pure copper as a cathode, electrolysis using a copper sulfate solution, pure copper precipitated at the cathode, the electrolyte is a copper sulfate solution with a concentration of 150g / L-250g / L, and the electrolysis current density is 100A / m 2 -200A / m 2 , electrolysis duration: 6h-12h.

[0035] Example 1: Conventional vacuum distillation

[0036] 1. Raw material preparation:

[0037] Collect 1 ton of metal smelting slag, crush it to 0.5 mm, and dry it to a moisture content of <1%.

[0038] 2. Vacuum distillation:

[0039] Place the smelting slag into a vacuum distillation furnace and adjust the vacuum degree to 5Pa.

[0040] Gradually heat to 1000°C, maintain for 3 hours, and monitor the sulfur volatilization.

[0041] 3. Condensation and collection:

[0042] The temperature of the condensation system was maintained at 10°C and about 50 kg of condensate was collected.

[0043] 4. Cooling and curing:

[0044] The high temperature residue is quickly cooled and solidified into blocks.

[0045] 5. Purification:

[0046] The collected copper liquid is cast into anode plates for electrolytic refining. The concentration of copper sulfate solution is 250g / L and the current density is 200A / m 2 , electrolysis for 8 hours, and 20 kg of pure copper was obtained.

[0047] Embodiment 2:

[0048] 1. Raw material preparation:

[0049] Collect 1 ton of metal smelting slag, crush it to 1 mm, and dry it to a moisture content of <0.5%.

[0050] 2. Vacuum distillation:

[0051] Place the smelting slag into a vacuum distillation furnace and adjust the vacuum degree to 2Pa.

[0052] Gradually heat to 1100°C, maintain for 4 hours, and monitor the sulfur volatilization.

[0053] 3. Condensation and collection:

[0054] The temperature of the condensation system was maintained at 5°C and about 100 kg of condensate was collected.

[0055] 4. Cooling and curing:

[0056] The high temperature residue is quickly cooled and solidified into blocks.

[0057] 5. Purification:

[0058] The collected copper liquid is cast into anode plates for electrolytic refining. The concentration of copper sulfate solution is 280g / L and the current density is 250A / m 2 , electrolysis for 10 hours, 40kg of pure copper was obtained.

[0059] Embodiment three:

[0060] 1. Raw material preparation:

[0061] Collect 1 ton of metal smelting slag, crush it to 0.7 mm, and dry it to a moisture content of <0.5%.

[0062] 2. Vacuum distillation:

[0063] Put the smelting slag into the vacuum distillation furnace and adjust the vacuum degree in two steps: 5Pa in the first step and 2Pa in the second step.

[0064] Gradually heat to 1200°C and maintain for 2 hours to carry out the first step of distillation.

[0065] The temperature was lowered to 1050°C and maintained for 2 hours for the second step of distillation.

[0066] 3. Condensation and collection:

[0067] The temperature of the condensation system was maintained at 15°C and the condensate was collected twice, totaling 150 kg.

[0068] 4. Cooling and curing:

[0069] The high temperature residue is quickly cooled and solidified into blocks.

[0070] 5. Purification:

[0071] The collected copper liquid is cast into anode plates for electrolytic refining. The concentration of copper sulfate solution is 300g / L and the current density is 300A / m 2 , electrolyze for 12 hours, and obtain 60kg of pure copper:

[0072] In Example 1, the temperature and pressure cannot be accurately controlled, resulting in incomplete separation, impurities mixed in, single heating to high temperature, high energy consumption, low thermal energy utilization efficiency, low equipment utilization rate, fixed operating conditions, difficulty in adapting to different smelting slags, long equipment downtime, complex and dangerous high temperature and high pressure operations, low degree of automation, low copper purity, poor consistency, difficult to control volatile pollutants, complex waste treatment, high treatment cost, low recovery rate, waste of resources, fixed parameters, and difficulty in expansion and adjustment.

[0073] In Example 2, the temperature and pressure are slightly optimized, but still difficult to control accurately; the heating temperature is reduced, but still requires high energy consumption; the operating conditions are optimized, but the adaptability is still limited; the operating conditions are improved, but still require manual monitoring; the purity of copper is improved, but still needs to be further purified; the volatile pollutants are reduced, but the processing difficulty is still great; the processing cost is reduced, but the recovery rate is still low; the parameters are adjusted, but the scalability is still limited;

[0074] In Example 3, the temperature and pressure are gradually optimized to accurately control the separation conditions; heating is performed in steps to efficiently utilize heat energy; operating parameters are flexibly adjusted to adapt to different smelting slags and reduce downtime; heating and cooling are performed gradually, risks are reduced, and the degree of automation is high; copper purity is high and consistency is good; pollutants are treated in a graded manner and waste treatment is simplified; low processing costs, high recovery rates, and high resource utilization rates; strong adaptability, good scalability, and flexible parameter adjustment.

[0075] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for desulfurizing and enriching copper from metal smelting slag by vacuum distillation, characterized in that: The method for vacuum distillation desulfurization and enrichment of copper from metal smelting slag has the following steps: Step 1: Raw material preparation, collect metal smelting slag and crush the smelting slag to uniform particle size, pre-dry at 120°C to remove moisture; Step 2: Vacuum distillation setup: Assemble the vacuum distillation equipment, including the distillation furnace, condenser and collection container, ensure that the vacuum system is intact and leak-free, the connections are tight, and set the vacuum degree to provide a low-pressure environment for the subsequent desulfurization process; Step 3: Vacuum distillation: put the smelting slag into a vacuum distillation furnace, and adjust the vacuum degree in two steps: 5Pa in the first step and 2Pa in the second step. Gradually heat to 1200℃, keep for 2 hours, and perform the first step of distillation. Lower the temperature to 1050℃, keep for 2 hours, and perform the second step of distillation. Step 4: Condensation and collection, introducing the volatile gas into the condenser, using the cooling medium cold water or nitrogen to cool the gas to a liquid state, collecting the condensed copper-enriched liquid or solid in the collection container of the condenser, and introducing the condensed gas into the sulfide absorption device, and recovering the sulfide in the condensed gas through sodium hydroxide solution or alkaline adsorbent; Step 5: Cooling and solidification. After the distillation is completed, the high-temperature residue is quickly removed from the distillation furnace and placed in a cooling area. The temperature is quickly lowered to room temperature using an air cooling or water cooling system. The cooled residue solidifies into a block for subsequent processing and storage. Step 6: Purification of enriched copper: preliminary screening of the collected condensate to remove impurities, casting the collected enriched copper liquid or solid into a plate and placing it in an electrolytic cell as an anode, using pure copper as the cathode, electrolysis using a copper sulfate solution, and precipitation of pure copper at the cathode.

2. A method for desulfurizing and enriching copper from metal smelting slag by vacuum distillation according to claim 1, characterized in that: The particle size of the smelting slag in the step 1 is 0.5mm-1mm.

3. The method for desulfurizing and enriching copper from metal smelting slag by vacuum distillation according to claim 1, characterized in that: In the step 2, the vacuum degree is set to 1Pa-10Pa.

4. The method for desulfurizing and enriching copper from metal smelting slag by vacuum distillation according to claim 1, characterized in that: In the step 3, the heating temperature is controlled within the range of 850° C.-1200° C., and the distillation time is controlled within 2 hours-4 hours.

5. The method for desulfurizing and enriching copper from metal smelting slag by vacuum distillation according to claim 1, characterized in that: In the step 4, the temperature of the condensation system is maintained at 0°C-20°C to improve the condensation efficiency.

6. The method for desulfurizing and enriching copper from metal smelting slag by vacuum distillation according to claim 1, characterized in that: In step 5, the electrolyte is a copper sulfate solution with a concentration of 150 g / L-250 g / L and an electrolysis current density of 100 A / m 2 -200A / m 2 , electrolysis duration: 6h-12h.