A method for separating copper and lead from copper smelting fumes and its application

Abstract

The application discloses a method for separating copper and lead from copper smelting flue dust and application thereof. The treatment method comprises the following steps: S1, mixing the copper smelting flue dust with water, sieving, and separating to obtain a first slurry and copper-rich sieve residue; S2, adding sulfuric acid into the first slurry, heating, then adding an oxidizing agent and controlling the final oxidation-reduction potential to be 250-300 mv, cooling after reaction, and obtaining a second slurry; S3, pumping the second slurry into a gravity separation device, separating light slurry and heavy slurry, then filtering the heavy slurry, collecting first filter residue to obtain copper-rich residue; filtering the light slurry, collecting second filter residue to obtain lead-rich residue; and combining the first filtrate and the second filtrate to obtain a copper sulfate solution. The method of the application does not need to introduce a weighting agent, the copper content in the produced lead-rich residue is also lower, which helps to improve the purification treatment efficiency of lead and copper in the later stage, and meanwhile reduces the loss of copper.

Description

Technical Field

[0001] This invention relates to the field of metal recycling technology, and in particular to a method and application for separating copper and lead from copper smelting fumes. Background Technology

[0002] Copper smelting dust is a grayish-white solid particulate matter formed by volatilization during the smelting of copper-containing minerals. Its composition is complex, containing not only valuable metals such as copper, lead, zinc, cadmium, bismuth, gold and silver, but also toxic substances such as arsenic. These substances mainly exist in the form of oxides, sulfides, sulfates, arsenates and their complex salts.

[0003] In related technologies, methods for separating and recovering metal ions from copper smelting fumes are mainly divided into hydrometallurgical, pyrometallurgical, hydrometallurgical-pyrometallurgical combined processes, and beneficiation-smelting combined processes. Hydrometallurgical processes are mainly divided into acid leaching and alkaline leaching. In acid leaching, most copper, zinc, cadmium, and arsenic enter the solution, while lead is enriched in the leaching residue. Because the composition and structure of copper smelting fumes are greatly affected by raw materials, furnace type, furnace conditions, and smelting processes, the copper recovery rate during acid leaching is generally around 30%–95%, exhibiting drawbacks such as large fluctuations in recovery rate and difficulty in production control. In alkaline leaching, copper remains in the leaching residue, while most lead, zinc, cadmium, and arsenic enter the solution, with some remaining in the leaching residue. Therefore, the leaching residue contains not only copper but also a large amount of lead and arsenic, resulting in poor separation of copper and lead. Pyrometallurgical processes primarily involve mixing copper smelting flue gas with lead-zinc ore, mainly to recover secondary metals like lead and zinc, with the recovery of other metals as a secondary objective. However, pyrometallurgical processes (such as solidification roasting) easily lead to the loss of metals like copper and lead, and produce large amounts of slag. Hydrometallurgical-pyrometallurgical combined processes typically involve first acid leaching copper, zinc, cadmium, and arsenic from copper smelting flue gas, followed by pyrometallurgical lead smelting to recover lead from the leaching slag. This process is complex and costly. Combined beneficiation and smelting processes combine hydrometallurgical or pyrometallurgical processes with mineral processing. Typically, copper smelting flue gas is first pyrometallurgically roasted, allowing lead and zinc to enter the flue gas first. The roasting products are then gravity separated to obtain copper. However, in practical applications, lead recovery rates are low.

[0004] Therefore, there is an urgent need to find a simple, low-cost, and widely applicable method for separating copper and lead from copper smelting fumes. Summary of the Invention

[0005] This invention aims to at least solve one of the technical problems existing in the prior art. To this end, this invention proposes a method for separating copper and lead from copper smelting fumes. The method of this invention can effectively reduce the copper carried away by lead slag, thereby improving the total copper and lead recovery rate.

[0006] The present invention also proposes the application of the above-mentioned method for separating copper and lead from copper smelting fumes in lead separation.

[0007] The present invention also proposes the application of the above-mentioned method for separating copper and lead from copper smelting fumes in the separation of copper.

[0008] A first aspect of the present invention provides a method for separating copper and lead from copper smelting fumes, comprising the following steps:

[0009] S1. Mix copper smelting fumes with water, sieve, and separate to obtain the first slurry and copper-rich sieve residue;

[0010] S2. Add sulfuric acid to the first slurry, heat, then add oxidant and control the endpoint oxidation-reduction potential to 250-300 mV, continue the reaction and then cool to obtain the second slurry;

[0011] S3. Pump the second slurry into the gravity separation device to separate the light slurry and the heavy slurry. Then filter the heavy slurry and collect the first filter residue to obtain copper-rich slag. Filter the light slurry and collect the second filter residue to obtain lead-rich slag. Combine the first filtrate and the second filtrate to obtain a copper sulfate solution.

[0012] The method for treating copper smelting fumes according to embodiments of the present invention has at least the following beneficial effects:

[0013] (1) By pre-screening to remove large copper compounds that are difficult to leach, the present invention achieves higher leaching efficiency and lower copper content in the lead-rich slag produced under the same oxidant dosage, resulting in a higher total copper recovery rate. In addition, the present invention utilizes copper smelting dust to mix with water beforehand, which can directly eliminate agglomeration without the need for other crushing facilities.

[0014] (2) This invention proposes to improve the copper-lead separation effect by controlling the endpoint redox potential (250-300 mV). On the one hand, this helps to selectively oxidize copper sulfide (d=4.6) and cuprous sulfide (d=5.6) in copper fumes to cuprous oxide (d=6.0), avoiding further oxidation of cuprous oxide to copper oxide and saving the amount of oxidant used. On the other hand, cuprous oxide can further react with sulfuric acid to generate soluble copper sulfate and insoluble elemental copper (d=8.96); while lead, another major substance in copper fumes, mainly exists in the form of lead sulfate and lead oxide. The high-density lead oxide (d=9.5) generates low-density lead sulfate (d=6.2) during acid leaching. The specific gravity of elemental copper is much greater than that of lead sulfate, so copper-rich slag and lead-rich slag can be easily separated during gravity separation. The chemical reactions involved are as follows:

[0015] 2CuS↓+O2=Cu2S↓+SO2;

[0016] 2Cu2S↓+3O2=2Cu2O↓+2SO2;

[0017] Cu2O↓+H2SO4=CuSO4+Cu↓+H2O;

[0018] PbO↓+H2SO4=PbSO4↓+H2O.

[0019] (3) Based on the present invention, an oxidative acid leaching method is used for treatment. During acid leaching, copper, zinc, arsenic, and cadmium in the copper fume will enter the solution in the form of sulfate or arsenate compounds, which helps to increase the specific gravity of the solution. After the copper fume is leached, the slurry is directly reselected without the need to add additional weighting agents. The method of the present invention can effectively reduce the copper carried away by the lead slag, thereby improving the total copper and lead recovery rate in subsequent processing.

[0020] In some embodiments of the present invention, in step S1, the mass-to-volume ratio of copper smelting dust to water is 1g:3-5mL. A higher solid-liquid ratio can easily cause clogging during sieving, and since the filtered slurry needs to be leached with sulfuric acid later, the solution will evaporate during the heating reaction, further reducing the water content and making the slurry viscous after the subsequent reaction, which is not conducive to subsequent gravity separation. On the other hand, a lower solid-liquid ratio will lead to waste of sulfuric acid, and different gravity separation equipment usually have certain differences in the concentration requirements of the slurry.

[0021] In some embodiments of the present invention, in step S1, the copper smelting dust contains, by mass fraction, 8%–20% Cu, 15%–40% Pb, 2%–15% Zn, 0.35%–4.5% Cd, and 4%–15% As.

[0022] In some embodiments of the present invention, in step S1, the mass-to-volume ratio of copper smelting flue dust to water is 1g:3-5mL.

[0023] In some embodiments of the present invention, in step S1, the mesh size of the sieve is 200 to 325 mesh.

[0024] In some embodiments of the present invention, in step S1, the post-processing of the copper-rich screen oversize includes returning it to copper smelting and / or blowing treatment.

[0025] In some embodiments of the present invention, in step S2, the initial sulfuric acid concentration in the solution after adding the sulfuric acid is 6% to 8%.

[0026] In some embodiments of the present invention, in step S2, the heating temperature is 80-95°C.

[0027] In some embodiments of the present invention, the reaction time in step S2 is 2 to 4 hours.

[0028] In some embodiments of the present invention, in step S2, the oxidant is hydrogen peroxide and / or sodium hypochlorite.

[0029] In some embodiments of the present invention, in step S3, the gravity separation device is selected from any one of a hydrocyclone, a spiral concentrator, and a spiral chute.

[0030] In some embodiments of the present invention, the hydrocyclone is a hydrocyclone, and / or the feed pressure of the hydrocyclone is 0.15-0.25 MPa.

[0031] In some embodiments of the present invention, the ratio of the major axis to the minor axis of the inner surface of the spiral groove of the spiral concentrator is 4:0.8 to 1.2.

[0032] In some embodiments of the present invention, in step S3, the post-treatment of the copper-rich slag includes return to copper smelting and / or blowing treatment.

[0033] A second aspect of the present invention provides the application of the method for separating copper and lead from copper smelting dust as described in any of the first aspects in the separation of lead.

[0034] A third aspect of the present invention provides the application of the method for separating copper and lead from copper smelting dust as described in any of the first aspects in the separation of copper.

[0035] According to the application of the embodiments of the present invention, at least the following beneficial effects are achieved: using the method of the present invention to separate copper can improve the copper recovery rate and reduce the copper content in lead-rich slag.

[0036] Other features and advantages of the present invention will be set forth in the following description. Attached Figure Description

[0037] The present invention will be further described below with reference to the accompanying drawings and embodiments, wherein:

[0038] Figure 1 This is a flowchart of the copper smelting fume treatment method of the present invention. Detailed Implementation

[0039] The following will describe the concept and technical effects of the present invention clearly and completely with reference to embodiments, so as to fully understand the purpose, features and effects of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are all within the scope of protection of the present invention.

[0040] The terms "preferred," "more preferably," etc., used in this invention refer to embodiments of the invention that provide certain beneficial effects under certain circumstances. However, other embodiments may also be preferred under the same or other circumstances. Furthermore, the description of one or more preferred embodiments does not imply that other embodiments are unavailable, nor is it intended to exclude other embodiments from the scope of this invention.

[0041] When a numerical range is disclosed herein, the range is considered continuous and includes the minimum and maximum values ​​of the range, as well as every value between the minimum and maximum values. Furthermore, when the range refers to integers, it includes every integer between the minimum and maximum values ​​of the range. Additionally, when multiple ranges are provided to describe a feature or characteristic, the ranges may be combined. In other words, unless otherwise specified, all ranges disclosed herein should be understood to include any and all subranges to which they are incorporated.

[0042] In the description of this invention, the reference term "and / or" includes all and any combination of one or more of the associated listed items.

[0043] In the description of this invention, the terms "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0044] Unless otherwise specified in the examples, the procedures should be performed under standard conditions or conditions recommended by the manufacturer. Reagents or instruments whose manufacturers are not specified are all commercially available products.

[0045] like Figure 1 As shown, the present invention provides a method for separating copper and lead from copper smelting fumes, specifically including the following steps:

[0046] S1. Mix copper smelting fumes with water, sieve, and separate large copper-rich particles from the sieve oversize and the first slurry (undersize). At the same time, collect the first slurry to proceed to the next step.

[0047] S2. Add concentrated sulfuric acid to the first slurry above, control the initial sulfuric acid concentration in the solution to 6% to 8%, and slowly add oxidant, control the endpoint oxidation-reduction potential (ORP) to 250 to 300 mV, continue the reaction for a period of time and then cool to obtain the second slurry;

[0048] S3. The obtained second slurry is pumped into a gravity separator to separate the light slurry and the heavy slurry. Then, the heavy slurry is filtered to collect the first filter residue to obtain copper-rich slag. The light slurry is filtered to collect the second filter residue to obtain lead-rich slag. The first filtrate and the second filtrate are combined to obtain a copper sulfate solution.

[0049] In some embodiments of the present invention, the copper smelting dust contains, by mass fraction, 8%–20% Cu, 15%–40% Pb, 2%–15% Zn, 0.35%–4.5% Cd, and 4%–15% As.

[0050] In some embodiments of the present invention, the mixing ratio of copper smelting dust and water in step S1 is preferably 1g:3-5mL, and the mesh size of the sieve for sieving is preferably 200-325 mesh; the large particles separated on the sieve are mainly metallic copper and cuprous sulfide, which can be directly returned to copper smelting and blowing treatment.

[0051] Specifically, copper smelting processes include flash smelting, Noranda pool smelting, and top-blown submerged smelting, while copper blowing processes include converter blowing and flash furnace blowing.

[0052] This invention removes most of the difficult-to-decompose copper through pre-screening, resulting in higher leaching efficiency under the same oxidant dosage, lower copper content in the produced lead-rich slag, and a higher total copper recovery rate. Simultaneously, the copper ash is pre-mixed with water, directly breaking up agglomeration without the need for additional crushing equipment.

[0053] In some embodiments of the present invention, the oxidant is hydrogen peroxide and / or sodium hypochlorite.

[0054] In some embodiments of the present invention, the gravity separation device is selected from an FX-125 hydrocyclone or a spiral concentrator. When the gravity separation device is an FX-125 hydrocyclone, the feed pressure is 0.15–0.25 MPa. When the gravity separation device is a spiral concentrator, the ratio of the major axis to the minor axis of the inner surface of the spiral groove is 4:0.8–1.2.

[0055] The method of the present invention will be described in detail below with reference to embodiments.

[0056] Example 1

[0057] This embodiment provides a method for separating copper and lead from copper smelting dust, wherein the copper smelting dust used is converter dust, and the mass fraction of the main elements is shown in Table 1.

[0058] Table 1: Mass fraction of major elements in copper smelting dust

[0059] Cu Pb Zn Cd As 10.9％ 36.6％ 2.5％ 0.41％ 8.2％

[0060] The methods for treating copper smelting fumes described above specifically include the following:

[0061] (1) Screening process:

[0062] Copper smelting fumes are mixed with water at a solid-liquid ratio of 2000g:10L, and then passed through a 200-mesh sieve to separate large copper-rich particles from the oversize material and the first slurry (undersize material). The copper-rich oversize material can be combined with copper concentrate and returned to the copper smelting process to recover copper, while the first slurry (undersize material) enters the next step.

[0063] (2) Oxidative acid leaching treatment:

[0064] Add 890g of concentrated sulfuric acid to the first slurry to control the initial sulfuric acid concentration at 8%, then heat to 85°C while slowly adding 27.5% industrial hydrogen peroxide, controlling the endpoint oxidation-reduction potential (ORP) to 280mV. Add a total of 160g of 27.5% industrial hydrogen peroxide, continue the reaction for 3 hours, and then cool to room temperature to obtain the second slurry.

[0065] (3) Separation of lead slag:

[0066] The second slurry obtained above is directly pumped into an FX-125 hydrocyclone at a feed pressure of 0.15 MPa to separate the underflow heavy slurry and the overflow light slurry. The underflow slurry is filtered to obtain copper-rich slag; the overflow slurry is filtered to obtain lead-rich slag. The underflow filtrate and the overflow filtrate are combined to obtain a copper sulfate solution.

[0067] The Cu and Pb content in the isolates from the above stages was detected, and the results are shown in Table 2.

[0068] Table 2: Detection of Cu and Pb elemental content in each isolate from Example 1

[0069]

[0070] Based on the above test results, it can be seen that the method of the present invention can separate copper and lead in copper smelting fumes. The recovery rate of Pb in the recovered lead-rich slag reaches 95.22%, and the loss rate of Cu is only 1.41% (i.e. the part carried away by the lead-rich slag). This is helpful for the subsequent classification and treatment of lead-rich slag and copper-containing components (such as sieve oversize, copper-rich slag and copper sulfate solution).

[0071] Example 2

[0072] This embodiment provides a method for separating copper and lead from copper smelting dust, wherein the copper smelting dust used is converter dust, and its main components are shown in Table 1.

[0073] The methods for treating copper smelting fumes described above specifically include the following:

[0074] (1) Screening process:

[0075] Copper smelting fumes are mixed with water at a solid-liquid ratio of 2000g:10L, and then passed through a 200-mesh sieve to separate large copper-rich particles from the oversize material and the first slurry (undersize material). The copper-rich oversize material can be combined with copper concentrate and returned to the copper smelting process to recover copper, while the first slurry (undersize material) enters the next step.

[0076] (2) Oxidative acid leaching treatment:

[0077] Add 890g of concentrated sulfuric acid to the first slurry to control the initial sulfuric acid concentration at 8%, then heat to 85°C while slowly adding 27.5% industrial hydrogen peroxide, controlling the endpoint oxidation-reduction potential (ORP) to 280mV. Add a total of 160g of 27.5% industrial hydrogen peroxide, continue the reaction for 3 hours, and then cool to room temperature to obtain the second slurry.

[0078] (3) Separation of lead slag:

[0079] The second slurry obtained above is directly pumped into an FX-125 hydrocyclone at a feed pressure of 0.25 MPa to separate the underflow heavy slurry and the overflow light slurry. The underflow slurry is filtered to obtain copper-rich slag; the overflow slurry is filtered to obtain lead-rich slag. The underflow filtrate and the overflow filtrate are combined to obtain a copper sulfate solution.

[0080] The Cu and Pb content in the isolates from the above stages was detected, and the results are shown in Table 3.

[0081] Table 3: Detection of Cu and Pb elemental content in each isolate from Example 2

[0082]

[0083] Based on the above test results, it can be seen that the method of the present invention can separate copper and lead in copper smelting fumes. The recovery rate of Pb in the recovered lead-rich slag reaches 96.14%, while the loss rate of Cu is only 1.14%.

[0084] Example 3

[0085] This embodiment provides a method for separating copper and lead from copper smelting fumes. The main components of the copper smelting fumes used are shown in Table 1. Based on the above-mentioned method for treating copper smelting fumes, the specific contents include the following.

[0086] (1) Screening process:

[0087] The copper smelting dust was mixed with water at a solid-liquid ratio of 2000g:6L, and then passed through a 250-mesh sieve to separate the large particles on the sieve and the first slurry (undersize). The copper-rich sieve material can be combined with copper concentrate and returned to the copper smelting process to recover copper. The first slurry (undersize) enters the next step.

[0088] (2) Oxidative acid leaching treatment:

[0089] Add 530g of concentrated sulfuric acid to the first slurry to control the initial sulfuric acid concentration at 8%, then heat to 95°C while slowly adding 27.5% industrial hydrogen peroxide, controlling the endpoint oxidation-reduction potential (ORP) to 260mV. Add a total of 140g of 27.5% industrial hydrogen peroxide, continue the reaction for 4 hours, and then cool to room temperature to obtain the second slurry.

[0090] (3) Separation of lead slag:

[0091] The second slurry obtained above is directly pumped into a spiral concentrator with a long axis to short axis ratio of 4:1 on the inner surface of the spiral channel for gravity separation, separating light slurry and heavy slurry. The heavy slurry is filtered to obtain copper-rich slag; the light slurry is filtered to obtain lead-rich slag. The light slurry filtrate and the heavy slurry filtrate are combined to obtain copper sulfate solution.

[0092] The Cu and Pb content in the isolates from the above stages was detected, and the results are shown in Table 4.

[0093] Table 4: Detection of Cu and Pb elemental content in each isolate from Example 3

[0094]

[0095]

[0096] Based on the above test results, it can be seen that the method of the present invention can separate copper and lead in copper smelting dust, wherein the recovery rate of Pb in the recovered lead-rich slag reaches 91.17%, and the loss rate of Cu is 2.02%.

[0097] Example 4

[0098] This embodiment provides a method for separating copper and lead from copper smelting fumes. The main components of the copper smelting fumes used are shown in Table 1. Based on the above-mentioned method for treating copper smelting fumes, the specific contents include the following.

[0099] (1) Screening process:

[0100] The copper smelting dust was mixed with water at a solid-liquid ratio of 2000g:6L, and then passed through a 250-mesh sieve to separate the large particles on the sieve and the first slurry (undersize). The copper-rich sieve material can be combined with copper concentrate and returned to the copper smelting process to recover copper. The first slurry (undersize) enters the next step.

[0101] (2) Oxidative acid leaching treatment:

[0102] Add 530g of concentrated sulfuric acid to the first slurry to control the initial sulfuric acid concentration at 8%, then heat to 95°C while slowly adding 27.5% industrial hydrogen peroxide, controlling the endpoint oxidation-reduction potential (ORP) to 260mV. Add a total of 140g of 27.5% industrial hydrogen peroxide, continue the reaction for 4 hours, and then cool to room temperature to obtain the second slurry.

[0103] (3) Separation of lead slag:

[0104] The second slurry obtained above is directly pumped into an FX-125 hydrocyclone at a feed pressure of 0.22 MPa to separate the underflow heavy slurry and the overflow light slurry. The underflow slurry is filtered to obtain copper-rich slag; the overflow slurry is filtered to obtain lead-rich slag. The underflow filtrate and the overflow filtrate are combined to obtain a copper sulfate solution.

[0105] The Cu and Pb content in the isolates from the above stages was detected, and the results are shown in Table 5.

[0106] Table 5: Detection of Cu and Pb elemental content in each isolate from Example 4

[0107]

[0108] Based on the above test results, it can be seen that the method of the present invention can separate copper and lead in copper smelting fumes, wherein the recovery rate of Pb in the recovered lead-rich slag reaches 94.61%, and the loss rate of Cu is 1.64%.

[0109] Example 5

[0110] This embodiment provides a method for separating copper and lead from copper smelting fumes. The main components of the copper smelting fumes used are shown in Table 1. Based on the above-mentioned method for treating copper smelting fumes, the specific contents include the following.

[0111] (1) Screening process:

[0112] The copper smelting dust was mixed with water at a solid-liquid ratio of 2000g:6L, and then passed through a 250-mesh sieve to separate the large particles on the sieve and the first slurry (undersize). The copper-rich sieve material can be combined with copper concentrate and returned to the copper smelting process to recover copper. The first slurry (undersize) enters the next step.

[0113] (2) Oxidative acid leaching treatment:

[0114] Add 460g of concentrated sulfuric acid to the first slurry to control the initial sulfuric acid concentration at 7%, then heat to 80°C, while slowly adding 10% industrial sodium hypochlorite, controlling the endpoint oxidation-reduction potential (ORP) to 290mV, and add a total of 150g of 10% industrial sodium hypochlorite. Continue the reaction for 4 hours and then cool to room temperature to obtain the second slurry.

[0115] (3) Separation of lead slag:

[0116] The second slurry obtained above is directly pumped into an FX-125 hydrocyclone at a feed pressure of 0.20 MPa to separate the underflow heavy slurry and the overflow light slurry. The underflow slurry is filtered to obtain copper-rich slag; the overflow slurry is filtered to obtain lead-rich slag. The underflow filtrate and the overflow filtrate are combined to obtain a copper sulfate solution.

[0117] The Cu and Pb content in the isolates from the above stages was detected, and the results are shown in Table 6.

[0118] Table 6: Detection of Cu and Pb elemental content in each isolate from Example 5

[0119]

[0120] Based on the above test results, it can be seen that the method of the present invention can separate copper and lead in copper smelting fumes, wherein the recovery rate of Pb in the recovered lead-rich slag reaches 94.94%, and the loss rate of Cu is 1.18%.

[0121] Comparative Example 1

[0122] This comparative example provides a method for separating copper and lead from copper smelting fumes, which uses the same liquid-to-solid ratio, sulfuric acid addition, hydrogen peroxide addition, and reaction time as Example 1. The difference is that the copper and lead slag is directly leached without screening and then separated by gravity separation. The specific method is as follows:

[0123] (1) Oxidative acid leaching treatment:

[0124] Copper smelting fumes were mixed with water at a solid-liquid ratio of 2000g:10L. 890g of concentrated sulfuric acid was added to control the initial concentration of sulfuric acid at 8%. The mixture was then heated to 85°C while 160g of 27.5% industrial hydrogen peroxide was slowly added. The endpoint oxidation-reduction potential (ORP) was 210mV. The reaction was continued for 3 hours and then cooled to room temperature.

[0125] (2) Separation of lead slag:

[0126] The above slurry is directly pumped into an FX-125 hydrocyclone at a feed pressure of 0.15 MPa to separate the underflow heavy slurry and the overflow light slurry. The underflow slurry is filtered to obtain copper-rich slag; the overflow slurry is filtered to obtain lead-rich slag. The underflow filtrate and the overflow filtrate are combined to obtain a copper sulfate solution.

[0127] The Cu and Pb content in the isolates from the above stages was detected, and the results are shown in Table 7.

[0128] Table 7: Detection of Cu and Pb elemental contents in each isolate of Comparative Example 1

[0129]

[0130] Based on the above test results, it can be seen that when copper and lead are separated from copper smelting fumes using this method, the recovery rate of Pb in the recovered lead-rich slag reaches 94.65%, but the loss rate of Cu reaches 10.85%.

[0131] Comparative Example 2

[0132] This comparative example provides a method for separating copper and lead from copper smelting fumes. It uses the same liquid-to-solid ratio, sulfuric acid dosage, and reaction time as Example 1, differing only in the amount of hydrogen peroxide added. Its ORP is 410 mV. The specific method is as follows:

[0133] (1) Screening process:

[0134] Copper smelting fumes are mixed with water at a solid-liquid ratio of 2000g:10L, and then passed through a 200-mesh sieve to separate large copper-rich particles from the oversize material and the first slurry (undersize material). The copper-rich oversize material can be combined with copper concentrate and returned to the copper smelting process to recover copper, while the first slurry (undersize material) enters the next step.

[0135] (2) Acid leaching and oxidation treatment:

[0136] Add 890g of concentrated sulfuric acid to the first slurry to control the initial sulfuric acid concentration at 8%, then heat to 85°C while slowly adding 27.5% industrial hydrogen peroxide, controlling the endpoint oxidation-reduction potential (ORP) to 410mV. Add a total of 250g of 27.5% industrial hydrogen peroxide, continue the reaction for 3 hours, and then cool to room temperature to obtain the second slurry.

[0137] (3) Swirl separation:

[0138] The slurry obtained above was directly pumped into an FX-125 hydrocyclone at a feed pressure of 0.15 MPa to separate the underflow heavy slurry and the overflow light slurry. The underflow slurry was filtered to obtain copper-rich slag; the overflow slurry was filtered to obtain lead-rich slag. The underflow filtrate and overflow filtrate were combined to obtain a copper sulfate solution. The Cu and Pb content in the separated products of each stage was detected, and the results are shown in Table 8.

[0139] Table 8: Detection of Cu and Pb elemental contents in each isolate of Comparative Example 2

[0140]

[0141] Based on the above test results, it can be seen that when copper and lead are separated in copper smelting fumes using this method, the loss rate of Cu in the recovered lead-rich slag is 0.67%, but the recovery rate of Pb is only 89.91%, with some of the lead being carried away by the copper slag.

[0142] Comparative Example 3

[0143] This comparative example provides a method for separating copper and lead from copper smelting fumes, which uses the same liquid-to-solid ratio, sulfuric acid addition, reaction time, and reselection parameters as Example 1, except that the endpoint oxidation-reduction potential (ORP) is controlled at 230 mV during oxidative acid leaching. The specific method is as follows:

[0144] (1) Screening process:

[0145] Copper smelting fumes are mixed with water at a solid-liquid ratio of 2000g:10L, and then passed through a 200-mesh sieve to separate large copper-rich particles from the oversize material and the first slurry (undersize material). The copper-rich oversize material can be combined with copper concentrate and returned to the copper smelting process to recover copper, while the first slurry (undersize material) enters the next step.

[0146] (2) Acid leaching and oxidation treatment:

[0147] Add 890g of concentrated sulfuric acid to the first slurry to control the initial sulfuric acid concentration at 8%, then heat to 85°C while slowly adding 27.5% industrial hydrogen peroxide, controlling the endpoint oxidation-reduction potential (ORP) to 230mV. Add a total of 120g of 27.5% industrial hydrogen peroxide, continue the reaction for 3 hours, and then cool to room temperature to obtain the second slurry.

[0148] (3) Swirl separation:

[0149] The slurry obtained above is directly pumped into an FX-125 hydrocyclone at a feed pressure of 0.15 MPa to separate the underflow heavy slurry and the overflow light slurry. The underflow slurry is filtered to obtain copper-rich slag; the overflow slurry is filtered to obtain lead-rich slag. The underflow filtrate and the overflow filtrate are combined to obtain a copper sulfate solution.

[0150] The Cu and Pb content in the isolates from the above stages was detected, and the results are shown in Table 9.

[0151] Table 9: Detection of Cu and Pb elemental contents in each isolate of Comparative Example 3

[0152]

[0153] Based on the above test results, it can be seen that the method can separate copper and lead in copper smelting fumes. The recovery rate of Pb in the recovered lead-rich slag is 94.94%, but the loss rate of Cu is 6.11%, which is presumably related to the incomplete oxidation of the first slurry.

[0154] Comparative Example 4

[0155] This comparative example provides a method for separating copper and lead from copper smelting fumes, which uses the same liquid-to-solid ratio, sulfuric acid addition, hydrogen peroxide addition, and reaction time as Example 1. The difference is that the copper-lead slag is not separated by gravity separation of the slurry after sieving and leaching. The specific method is as follows:

[0156] (1) Screening process:

[0157] Copper smelting fumes are mixed with water at a solid-liquid ratio of 2000g:10L, and then passed through a 200-mesh sieve to separate large copper-rich particles from the oversize material and the first slurry (undersize material). The copper-rich oversize material can be combined with copper concentrate and returned to the copper smelting process to recover copper, while the first slurry (undersize material) enters the next step.

[0158] (2) Acid leaching and oxidation treatment:

[0159] Add 890g of concentrated sulfuric acid to the first slurry to control the initial sulfuric acid concentration at 8%, then heat to 85℃ while slowly adding 27.5% industrial hydrogen peroxide, controlling the endpoint oxidation-reduction potential (ORP) to 280mV. Add a total of 160g of 27.5% industrial hydrogen peroxide, continue the reaction for 3 hours, cool to room temperature, filter, and obtain lead slag and copper sulfate solution.

[0160] The Cu and Pb content in the isolates from the above stages was detected, and the results are shown in Table 10.

[0161] Table 10: Detection of Cu and Pb elemental contents in each isolate of Comparative Example 4

[0162]

[0163] Based on the above test results, it can be seen that when using this method to separate copper and lead from copper smelting fumes, the recovery rate of Pb in the recovered lead-rich slag is 98.73%, while the loss rate of Cu is as high as 12.61%, making it difficult to effectively separate copper from lead slag.

[0164] Comparative Example 5

[0165] This comparative example provides a method for separating copper and lead from copper smelting flue dust, which uses the same liquid-to-solid ratio, sulfuric acid and hydrogen peroxide addition amounts, and reaction time as Example 1. The only difference is that the feed pressure during gravity separation hydrocyclone is 0.1 MPa. The specific method is as follows:

[0166] (1) Screening process:

[0167] Copper smelting fumes are mixed with water at a solid-liquid ratio of 2000g:10L, and then passed through a 200-mesh sieve to separate large copper-rich particles from the oversize material and the first slurry (undersize material). The copper-rich oversize material can be combined with copper concentrate and returned to the copper smelting process to recover copper, while the first slurry (undersize material) enters the next step.

[0168] (2) Acid leaching and oxidation treatment:

[0169] Add 890g of concentrated sulfuric acid to the first slurry to control the initial sulfuric acid concentration at 8%, then heat to 85°C while slowly adding 27.5% industrial hydrogen peroxide, controlling the endpoint oxidation-reduction potential (ORP) to 280mV. Add a total of 160g of 27.5% industrial hydrogen peroxide, continue the reaction for 3 hours, and then cool to room temperature to obtain the second slurry.

[0170] (3) Swirl separation:

[0171] The slurry obtained above is directly pumped into an FX-125 hydrocyclone at a feed pressure of 0.1 MPa to separate the underflow heavy slurry and the overflow light slurry. The underflow slurry is filtered to obtain copper-rich slag; the overflow slurry is filtered to obtain lead-rich slag. The underflow filtrate and the overflow filtrate are combined to obtain a copper sulfate solution.

[0172] The Cu and Pb content in the isolates from the above stages was detected, and the results are shown in Table 11.

[0173] Table 11: Detection of Cu and Pb elemental contents in each isolate of Comparative Example 5

[0174]

[0175] Based on the above test results, it can be seen that when copper and lead are separated from copper smelting fumes using this method, the recovery rate of Pb in the recovered lead-rich slag is 92.95%, but the loss rate of Cu reaches 8.3%. This shows that a feed pressure of 0.1 MPa is too low and is not conducive to copper-lead separation.

[0176] In summary, this invention provides a method and application for separating copper and lead from copper smelting fumes. The method of this invention can effectively reduce the copper carried away by lead slag, which helps to improve the recovery rate of total copper and lead in the subsequent process.

[0177] The 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. Furthermore, the embodiments of the present invention and the features thereof can be combined with each other unless otherwise specified.

Claims

1. A method for separating copper and lead from copper smelting fumes, characterized in that, Includes the following steps: S1. Mix copper smelting fumes with water, sieve, and separate to obtain the first slurry and copper-rich sieve residue; S2. Add sulfuric acid to the first slurry, heat, then add oxidant and control the endpoint oxidation-reduction potential to 250-300 mV, continue the reaction and then cool to obtain the second slurry; S3. Pump the second slurry into the gravity separation device to separate the light slurry and the heavy slurry, and then filter the heavy slurry to collect the first filter residue to obtain copper-rich slag. The light slurry is filtered, and the second filter residue is collected to obtain lead-rich slag; the first and second filtrates are combined to obtain a copper sulfate solution.

2. The method according to claim 1, characterized in that, In step S1, the mass-to-volume ratio of copper smelting fumes to water is 1g:3-5mL; And / or, the mesh size of the sieve used for sieving is 200 to 325 mesh.

3. The method according to claim 1, characterized in that, In step S1, the post-processing of the copper-rich screen oversize includes returning it to copper smelting and / or blowing treatment.

4. The method according to any one of claims 1 to 3, characterized in that, In step S2, the initial sulfuric acid concentration in the solution after adding the sulfuric acid is 6% to 8%. And / or, the heating temperature is 80–95°C; And / or, the reaction time is 2 to 4 hours.

5. The method according to claim 4, characterized in that, In step S2, the oxidant is hydrogen peroxide and / or sodium hypochlorite.

6. The method according to claim 5, characterized in that, In step S3, the gravity separation device is selected from any one of a hydrocyclone, a spiral concentrator, or a spiral chute.

7. The method according to claim 6, characterized in that, The hydrocyclone is a hydrocyclone, and / or the feed pressure of the hydrocyclone is 0.15-0.25 MPa.

8. The method according to claim 6, characterized in that, The ratio of the major axis to the minor axis on the inner surface of the spiral groove of the spiral concentrator is 4:0.8 to 1.

2.

9. The application of the method for separating copper and lead from copper smelting fumes as described in any one of claims 1 to 8 in the separation of lead.

10. The application of the method for separating copper and lead from copper smelting dust as described in any one of claims 1 to 8 in the separation of copper.

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