A method for high-efficiency and selective copper precipitation from cobalt-containing low-copper raffinate

Abstract

The application provides a method for efficient and selective copper precipitation from cobalt-containing low-copper raffinate, and relates to the field of hydrometallurgy. The method comprises the following steps: adding a coagulation-type sulfurizing agent solution and a polysulfide slurry of copper into the cobalt-containing low-copper raffinate to perform a selective and induced coagulation copper precipitation reaction, and then performing thickening to obtain thickening supernatant and thickening underflow. The thickening underflow is subjected to pressure filtration to obtain a post-pressure filtration liquid and a wet precipitate. The wet precipitate is dehydrated to form a dry precipitate, and a copper sulfide concentrate is obtained. The method for efficient and selective induced coagulation copper precipitation from cobalt-containing low-copper raffinate provided by the application is simple in process, high in economy and efficiency, high in selectivity, strong in coagulation capacity, and large in precipitated particle size, and can effectively improve the quality of subsequent cobalt salt. In addition, the copper product is easy to be recycled, and can be sent to a smelting plant for roasting-leaching process or directly sold as a copper concentrate, thereby avoiding the loss of valuable metals.

Description

Technical Field

[0001] This application relates to the field of hydrometallurgy, and in particular to a method for efficient and selective copper deposition in cobalt-containing low-copper raffinate. Background Technology

[0002] Extensive research has been conducted by domestic and international researchers on copper removal from cobalt-containing low-copper raffinate. Existing processes primarily involve increasing the pH of the iron removal stage, employing one or two stages of iron removal to allow copper ions to precipitate into the iron removal slag. While this process achieves relatively ideal copper removal results, the precipitation pH of copper and cobalt is quite similar. Therefore, increasing the system pH for copper removal leads to some cobalt precipitating into the iron removal slag, resulting in significant cobalt loss.

[0003] Chinese patent CN109266837A, published on January 25, 2019, discloses a method for recovering copper and cobalt from cobalt-containing waste liquid in a wet copper smelting process. This method first concentrates and separates the cobalt-containing waste liquid using nanofiltration membrane, then performs copper extraction, and finally neutralizes and precipitates the copper raffinate after impurity removal. However, the copper removal method used in this patent is limited by the extraction capacity of the extractant and the extraction process, resulting in a significant amount of copper remaining in the raffinate (copper ion concentration of 0.26 g / L in the example). Furthermore, this method increases the investment in additional equipment and is relatively complex.

[0004] Chinese patent CN107032416B, published on June 8, 2018, discloses a method for deep copper removal from a cobalt salt solution. This method involves two stages of copper removal: the first stage uses a copper-removing agent synthesized from reagents such as Na2CS3 and CoCl2, and the second stage uses cobalt thiocarbonate. The solution needs to be heated to 60-90 degrees Celsius before the copper removal reaction. Although the copper concentration in the solution can be reduced from 0.1-1 g / L to 1 mg / L, the Cu / Co mass ratio of the copper-removing slag reaches 15, resulting in poor selective copper removal. Furthermore, the copper-removing agent used has a certain degree of toxicity and is an uncommon reagent.

[0005] In the process of separating copper ions using sulfide precipitation, the resulting copper sulfide precipitate has a very fine particle size and particularly poor filtration and settling performance. It is also highly reactive and easily decomposes to re-form copper and sulfur ions. If not properly controlled, it will reduce the copper removal effect and worsen the filtration and settling performance, which poses great difficulties for engineering applications.

[0006] In view of the above, this application is hereby submitted. Summary of the Invention

[0007] The purpose of this application is to provide a method for efficient and selective copper deposition in cobalt-containing low-copper raffinate to solve the above-mentioned problems.

[0008] To achieve the above objectives, this application adopts the following technical solution:

[0009] A method for highly efficient and selective copper deposition in cobalt-containing low-copper raffinate includes:

[0010] Step 1: The coalescing sulfiding agent solution and the copper polysulfide slurry are added together to the cobalt-containing low-copper raffinate to selectively induce coalescence precipitation reaction. After the reaction, the mixture is thickened to obtain a thick supernatant and a thick underflow. The coalescing sulfiding agent is obtained by adding a flocculant to the sulfiding agent solution for coalescence treatment, and the copper polysulfides are obtained by adding a sulfiding agent to the copper concentrate for surface sulfidation treatment.

[0011] Sulfide ions have a strong affinity for copper ions, and the reaction between them is very rapid, forming extremely fine copper sulfide precipitates with very high reactivity. Generally, S... 2- With Cu 2+ The reaction is complete in 15 minutes, at which point the Cu in the solution will be... 2+ The concentration can be significantly reduced, but as time goes on, the fine CuS precipitate dissolves and decomposes back into the solution, causing the Cu concentration in the solution to increase. 2+ The concentration increases, and the precipitate becomes very difficult to filter and settle.

[0012] Step 2: Filter the concentrated underflow to obtain the filtrate and the precipitated wet residue;

[0013] Step 3: Dehydrate the precipitated wet residue to form precipitated dry residue, and obtain copper sulfide concentrate;

[0014] The precipitated residue is sent to a sulfide ore processing system to recover copper and cobalt or is recovered as copper sulfide concentrate.

[0015] The concentrated supernatant and the filtrate are combined to form a copper precipitation liquid for iron removal, and then used to produce crude cobalt hydroxide.

[0016] The cobalt-containing low-copper raffinate is a solution containing copper, cobalt, iron, and manganese impurity ions produced after leaching and copper extraction during the hydrometallurgical process of copper-cobalt oxide ore; the copper ion concentration in the cobalt-containing low-copper raffinate is 0.01-50 g / L, and the cobalt ion concentration is 0.01-50 g / L.

[0017] Preferably, the vulcanizing agent comprises substances capable of directly or indirectly providing S 2- Ionic substances.

[0018] Preferably, the sulfiding agent includes one or more of sulfide salts, hydrosulfide salts, thiosulfates, hydrogen sulfide, and sulfide minerals.

[0019] Preferably, the amount of the vulcanizing agent is 1-10 times the theoretical amount calculated based on the copper ions in the system.

[0020] Preferably, the selectively induced coalescence copper deposition reaction is carried out at a temperature of 5-100℃ for a time of 5-360 min.

[0021] Preferably, the amount of flocculant added to the coalescing vulcanizing agent solution is 0.5‰-5.0‰.

[0022] Preferably, the copper concentrate includes one or more of copper sulfide, cuprous sulfide, chalcopyrite, and chalcocite.

[0023] Preferably, water or the cobalt-containing low-copper raffinate is added during the surface sulfidation process to form a slurry.

[0024] Preferably, the copper recovery process of the sulfide ore treatment system includes: oxidative roasting, acid leaching, and oxygen pressure leaching of the precipitated dry residue.

[0025] Preferably, after the selectively induced agglomeration copper precipitation reaction, the copper precipitation rate is not less than 95% and the cobalt precipitation rate is not higher than 2%.

[0026] Preferably, the copper ion concentration in the copper precipitation solution is less than or equal to 5 mg / L, and the copper content in the precipitate residue is not less than 35%.

[0027] Compared with the prior art, the beneficial effects of this application include:

[0028] 1. The method for efficient and selective copper precipitation in cobalt-containing low-copper raffinate provided in this application uses a sulfiding agent to selectively induce the aggregation and precipitation of copper and cobalt in the solution, thereby achieving the purpose of removing copper from the cobalt-containing low-copper raffinate. The cobalt precipitation rate is extremely low, and copper and cobalt are separated. Copper enters the slag in the form of sulfides. The copper-containing precipitated slag is returned to the sulfide ore treatment system or sold as copper sulfide concentrate. While efficiently and selectively removing copper, it also realizes the recovery and utilization of metallic copper, which improves the quality of subsequent crude cobalt hydroxide and increases the copper recovery rate, resulting in significant economic benefits.

[0029] 2. The method for efficient and selective copper deposition in cobalt-containing low-copper raffinate provided in this application employs a coalescing-type sulfurizing agent for bridging and coalescing of S... 2- Slow down S 2- The diffusion rate of S is reduced. 2- The reactivity of S was achieved. 2- With Cu 2+ The slow reaction of CuS results in the formation of CuS that is bridged and encapsulated by flocculant groups, which deactivates the reactivity of CuS, avoids the drawback of easy decomposition of extremely fine CuS, and also causes the precipitate particles to aggregate and grow, thus improving the filtration and sedimentation performance.

[0030] 3. The method for efficient and selective copper precipitation in cobalt-containing low-copper raffinate provided in this application uses copper polysulfides formed by surface sulfidation treatment of copper concentrate as precipitation inducing agents. These polysulfide precipitation inducing agents reduce the energy required for CuS crystal nucleation and growth, while simultaneously adsorbing and precipitating multiple Cu crystals. 2+ The formation of CuS particle clusters provides an environment for the aggregation and growth of newly generated CuS crystals, further promoting the growth of CuS particles.

[0031] 4. This method achieves efficient removal of copper without losing cobalt in the solution. While the copper sulfide precipitation method is not original, this application is the first to propose using copper sulfide precipitation in low-copper raffinate and increasing the CuS particle size through induced agglomeration to achieve selective precipitation of copper and cobalt. Attached Figure Description

[0032] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly described below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation on the scope of this application.

[0033] Figure 1 For S 2- Relationship between metal ion concentration and concentration;

[0034] Figure 2 A schematic diagram of the process flow for a method of highly efficient and selective copper deposition of cobalt-containing low-copper raffinate provided in the embodiments;

[0035] Figure 3 Comparative photographs showing the precipitates formed after adding a coalescing vulcanizing agent and after adding sodium sulfide solution. Detailed Implementation

[0036] As used in this article:

[0037] "Prepared from" is synonymous with "comprising". The terms "comprising", "including", "having", "containing", or any other variations thereof as used herein are intended to cover non-exclusive inclusion. For example, a composition, step, method, article, or apparatus that includes the listed elements is not necessarily limited to those elements, but may include other elements not expressly listed or elements inherent to such composition, step, method, article, or apparatus.

[0038] The conjunction "composed of..." excludes any unspecified elements, steps, or components. If used in a claim, this phrase makes the claim closed, excluding materials other than those described, except for associated conventional impurities. When the phrase "composed of..." appears in a clause of the body of a claim rather than immediately following it, it limits only the elements described in that clause; other elements are not excluded from the claim as a whole.

[0039] When a quantity, concentration, or other value or parameter is expressed as a range, a preferred range, or a range defined by a series of upper and lower preferred values, this should be understood as specifically disclosing all ranges formed by any pair of any upper or preferred value with any lower or preferred value, regardless of whether the range is disclosed individually. For example, when the range “1–5” is disclosed, the described range should be interpreted as including ranges “1–4”, “1–3”, “1–2”, “1–2 and 4–5”, “1–3 and 5”, etc. When numerical ranges are described herein, unless otherwise stated, the range is intended to include its endpoints and all integers and fractions within that range.

[0040] In these embodiments, unless otherwise specified, the portions and percentages are all by weight.

[0041] "Parts by mass" refers to the basic unit of measurement that expresses the mass ratio of multiple components. One part can represent any unit mass, such as 1g or 2.689g. If we say that component A has "a" parts by mass and component B has "b" parts by mass, it means the ratio of the mass of component A to the mass of component B is a:b. Alternatively, it can mean that the mass of component A is aK and the mass of component B is bK (where K is any number representing a multiplier). It is important to understand that, unlike the number of parts by mass, the sum of the mass parts of all components is not limited to 100 parts.

[0042] "And / or" is used to indicate that one or both of the described situations may occur, for example, A and / or B includes (A and B) and (A or B).

[0043] A method for highly efficient and selective copper deposition in cobalt-containing low-copper raffinate includes:

[0044] Step 1: The coalescing sulfiding agent solution and the copper polysulfide slurry are added together to the cobalt-containing low-copper raffinate to selectively induce coalescence precipitation reaction. After the reaction, the mixture is thickened to obtain a thick supernatant and a thick underflow. The coalescing sulfiding agent is obtained by adding a flocculant to the sulfiding agent solution for coalescence treatment, and the copper polysulfides are obtained by adding a sulfiding agent to the copper concentrate for surface sulfidation treatment.

[0045] Step 2: Filter the concentrated underflow to obtain the filtrate and the precipitated wet residue;

[0046] Step 3: Dehydrate the precipitated wet residue to form precipitated dry residue, and obtain copper sulfide concentrate;

[0047] The precipitated residue is sent to a sulfide ore processing system to recover copper and cobalt or is recovered as copper sulfide concentrate.

[0048] The concentrated supernatant and the filtrate are combined to form a copper precipitation liquid for iron removal, and then used to produce crude cobalt hydroxide.

[0049] The cobalt-containing low-copper raffinate is a solution containing copper, cobalt, iron, and manganese impurity ions produced after leaching and copper extraction during the hydrometallurgical process of copper-cobalt oxide ore; the copper ion concentration in the cobalt-containing low-copper raffinate is 0.01-50 g / L, and the cobalt ion concentration is 0.01-50 g / L.

[0050] Metal ions and S 2- The order of chalcophileness of elements can be derived by arranging the solubility products of compounds from smallest to largest: Hg 2+ >Ag+>Cu 2+ >Pb 2+ >Cd 2+ >Zn 2+ >Co 2+ >Ni 2+ >Fe 2+ >Mn 2+ S 2- The relationship with metal ion concentration is as follows: Figure 1 As shown, Cu 2+ It has high chalcophilicity, and its chalcophilicity is much higher than that of Co. 2+ Therefore, certain reaction conditions can be controlled to preferentially promote Cu... 2+ CuS precipitate is generated, effectively achieving selective precipitation of copper.

[0051] The low-copper raffinate after copper removal is neutralized to remove iron and manganese, further purifying the pre-cobalt precipitation liquid. Then, crude cobalt hydroxide is produced through processes such as cobalt precipitation, filtration, and drying.

[0052] Optionally, the copper ion concentration in the cobalt-containing low-copper raffinate can be any value between 0.01 g / L, 0.05 g / L, 0.1 g / L, 0.5 g / L, 1 g / L, 5 g / L, 10 g / L, 15 g / L, 20 g / L, 25 g / L, 30 g / L, 35 g / L, 40 g / L, 45 g / L, 50 g / L, or 0.01-50 g / L, and the cobalt ion concentration can be any value between 0.01 g / L, 0.05 g / L, 0.1 g / L, 0.5 g / L, 1 g / L, 5 g / L, 10 g / L, 15 g / L, 20 g / L, 25 g / L, 30 g / L, 35 g / L, 40 g / L, 45 g / L, 50 g / L, or 0.01-50 g / L.

[0053] In an optional embodiment, the vulcanizing agent comprises substances capable of directly or indirectly providing S 2- Ionic substances.

[0054] In one alternative embodiment, the sulfiding agent includes one or more of sulfide salts, hydrosulfide salts, thiosulfates, hydrogen sulfide, and sulfide minerals.

[0055] In one optional embodiment, the amount of the vulcanizing agent is 1 to 10 times the theoretical amount calculated based on the copper ions in the system.

[0056] Optionally, the amount of the vulcanizing agent can be any value between 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 times or between 1 and 10 times the theoretical amount calculated based on the copper ions in the system.

[0057] In one optional embodiment, the selectively induced coalescence copper deposition reaction is carried out at a temperature of 5-100°C for a time of 5-360 min.

[0058] Optionally, the temperature for the selectively induced coalescence copper deposition reaction can be any value between 5°C, 10°C, 20°C, 30°C, 40°C, 50°C, 60°C, 70°C, 80°C, 90°C, 100°C, or 5-100°C, and the time can be any value between 5 min, 10 min, 30 min, 60 min, 90 min, 120 min, 150 min, 180 min, 210 min, 240 min, 270 min, 300 min, 330 min, 360 min, or 5-360 min.

[0059] In one optional embodiment, the amount of flocculant added to the coalescing vulcanizing agent solution is 0.5‰-5.0‰.

[0060] Optionally, the amount of flocculant added to the coalescing vulcanizing agent solution can be any value between 0.5‰, 1.0‰, 1.5‰, 2.0‰, 2.5‰, 3.0‰, 3.5‰, 4.0‰, 4.5‰, 5.0‰, or 0.5‰-5.0‰.

[0061] In an optional embodiment, the flocculant comprises a polyacrylamide-based organic polymer.

[0062] In one alternative embodiment, the copper concentrate comprises one or more of copper sulfide, cuprous sulfide, chalcopyrite, and chalcocite.

[0063] In an optional embodiment, water or the cobalt-containing low-copper raffinate is added during the surface sulfidation process to form a slurry.

[0064] In an optional implementation, the copper recovery from the sulfide ore processing system includes:

[0065] The precipitated residue is subjected to oxidative roasting, acid leaching, and oxygen pressure leaching.

[0066] The resulting precipitate, mainly copper sulfide precipitate, is fed into a roasting system. After roasting, it is converted into acid-soluble copper, which is then recovered through acid leaching. Alternatively, the obtained copper sulfide precipitate can be sold as copper concentrate. This step achieves effective recovery of copper removal products, avoiding the problem of copper loss into the slag that cannot be recovered due to conventional neutralization and precipitation methods.

[0067] The reaction equations involved are: 2CuS + 3O2 → 2CuO + 2SO2 (calcination) and CuO + H2SO4 → CuSO4 + H2O.

[0068] In an optional embodiment, after the selectively induced coalescence copper precipitation reaction, the copper precipitation rate is not less than 95% and the cobalt precipitation rate is not higher than 2%.

[0069] The implementation schemes of this application will be described in detail below with reference to specific embodiments. However, those skilled in the art will understand that the following embodiments are only for illustrating this application and should not be regarded as limiting the scope of this application. Unless otherwise specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall apply. Reagents or instruments used without specified manufacturers are all conventional products that can be purchased commercially.

[0070] Example 1

[0071] like Figure 2 As shown, this embodiment provides a method for highly efficient and selective copper deposition in cobalt-containing low-copper raffinate, specifically including the following steps:

[0072] Take 1000 mL of cobalt-containing low-copper raffinate. The main components are copper 0.32 g / L, cobalt 2.70 g / L, iron 1.23 g / L, manganese 1.18 g / L, and sulfuric acid 10.11 g / L.

[0073] Take twice the theoretical amount of sodium sulfide, i.e., 0.78g, dissolve it in 10ml of water, divide it into two portions, add 6003S flocculant to one portion for sulfidation and agglomeration to form a sulfidation agglomerate with a concentration of 1‰; add 5g of copper sulfide concentrate to the other portion for surface sulfidation treatment to obtain copper polysulfide slurry.

[0074] Stirring was started, and the sulfide agglomerating agent solution was slowly added dropwise to the low-copper raffinate using a dropper, while copper polysulfide slurry was added simultaneously. Timing was started after the addition was complete, and the reaction was allowed to proceed for 30 minutes. Stirring was then stopped, and the mixture was allowed to stand for 1 minute to allow for thickening and sedimentation. The supernatant was overflowed, and the underflow was filtered to obtain black copper sulfide slag. After dehydration, copper sulfide concentrate was obtained. Analysis showed that the copper concentration in the liquid after copper removal was 1.58 mg / L, with a copper precipitation rate greater than 95%. The copper sulfide slag contained 43.87% copper and 2.12% cobalt, with a cobalt loss rate of less than 1%.

[0075] Copper sulfide slag is returned to the sulfide ore processing system for copper and cobalt recovery or sold as copper sulfide concentrate. The overflow supernatant is combined with the filtered liquid to form copper precipitation liquid, which is sent to the iron removal process. After iron removal, it is used to produce crude cobalt hydroxide.

[0076] Example 2

[0077] This embodiment provides a method for highly efficient and selective copper deposition in cobalt-containing, low-copper raffinate, which specifically includes the following steps:

[0078] Take 1000 mL of cobalt-containing low-copper raffinate. The main components are copper 0.78 g / L, cobalt 2.65 g / L, iron 1.38 g / L, manganese 0.45 g / L, and sulfuric acid 13.82 g / L.

[0079] Take 2.73g of sodium hydrosulfide (4 times the theoretical amount) and dissolve it in 20ml of water. Divide it into two portions. Add 625V flocculant to one portion for sulfidation and agglomeration to form a sulfidation agglomerate with a concentration of 0.5‰. Add 2g of copper sulfide concentrate to the other portion for surface sulfidation treatment to obtain a copper polysulfide slurry.

[0080] Stirring was started, and the sulfide agglomerating agent solution and polysulfide slurry were slowly added dropwise to the low-copper raffinate using a dropper. Timing was started after the addition was complete, and the reaction was allowed to proceed for 30 minutes. Stirring was then stopped, and the mixture was allowed to settle for 30 seconds. The underflow was then collected and filtered to obtain black copper sulfide slag. After dehydration, copper sulfide concentrate was obtained. Analysis showed that the copper concentration in the liquid after copper removal was 1.23 mg / L, with a copper precipitation rate greater than 95%. The copper sulfide slag contained 43.21% copper and 2.23% cobalt, with a cobalt loss rate of less than 1%.

[0081] Copper sulfide slag is returned to the sulfide ore processing system to recover copper and cobalt or sold as copper sulfide concentrate. The liquid after copper precipitation is sent to the iron removal process, and after iron removal, it is used to produce crude cobalt hydroxide.

[0082] Example 3

[0083] This embodiment provides a method for highly efficient and selective copper deposition in cobalt-containing, low-copper raffinate, which specifically includes the following steps:

[0084] Take 1000 mL of cobalt-containing low-copper raffinate. The main components are copper 0.68 g / L, cobalt 2.51 g / L, iron 1.56 g / L, manganese 0.93 g / L, and sulfuric acid 12.17 g / L.

[0085] Take twice the theoretical amount of sodium thiosulfate, i.e., 1.67g, and dissolve it in 15ml of water. Divide it into two portions. Add 6003S flocculant to one portion for sulfidation and agglomeration to form a sulfidation and agglomeration agent with a concentration of 1.5‰. Add 50mL of copper sulfide concentrate thickened underflow to the other portion for surface sulfidation treatment to obtain a copper polysulfide slurry.

[0086] Stirring was started, and the sulfide agglomerating agent solution was slowly added dropwise to the low-copper raffinate using a dropper. Simultaneously, a polysulfide slurry that had undergone surface sulfidation treatment was added dropwise. Timing was started after the addition was complete, and the reaction was allowed to proceed for 40 minutes. Stirring was then stopped, and the mixture was allowed to settle and thicken. The thickened underflow was filtered to obtain copper-laden slag, which was then dehydrated to obtain copper sulfide concentrate. Analysis showed that the copper concentration in the liquid after copper removal was 3.01 mg / L, with a copper precipitation rate greater than 95%. The copper sulfide slag contained 45.22% copper and 1.12% cobalt, with a cobalt loss rate of less than 1%.

[0087] Copper sulfide slag is returned to the sulfide ore processing system to recover copper and cobalt or sold as copper sulfide concentrate. The liquid after copper precipitation is sent to the iron removal process, and after iron removal, it is used to produce crude cobalt hydroxide.

[0088] Example 4

[0089] This embodiment provides a method for highly efficient and selective copper deposition in cobalt-containing, low-copper raffinate, which specifically includes the following steps:

[0090] Take 1000 mL of cobalt-containing low-copper raffinate. The main components are copper 0.44 g / L, cobalt 3.01 g / L, iron 2.31 g / L, manganese 0.77 g / L, and sulfuric acid 10.11 g / L.

[0091] Hydrogen sulfide gas was introduced into a flocculant solution with a concentration of 1‰25E and a copper sulfide concentrate slurry to carry out sulfidation coalescence and surface sulfidation treatments, respectively, to obtain sulfidation coalescing agent and copper polysulfide slurry.

[0092] Hydrogen sulfide gas was introduced into the low-copper raffinate, while the aforementioned sulfide agglomerating agent and copper polysulfide slurry were slowly added. After reacting for 30 minutes, the mixture was allowed to settle, filtered through the underflow, and black copper sulfide slag was obtained. After dewatering, coarse-grained copper sulfide concentrate was obtained. Analysis showed that the copper concentration in the raffinate after copper removal was 3.18 mg / L, with a copper precipitation rate greater than 95%. The copper sulfide slag contained 41.87% copper and 1.72% cobalt, with a cobalt loss rate of less than 1%.

[0093] Copper sulfide slag is returned to the sulfide ore processing system to recover copper and cobalt or sold as copper sulfide concentrate. The liquid after copper precipitation is sent to the iron removal process, and after iron removal, it is used to produce crude cobalt hydroxide.

[0094] Comparative Example 1

[0095] Compared to Example 1, the same solution was used as the raw material. The difference was that no sulfidation agglomeration was performed; only the copper sulfide concentrate underwent surface sulfidation treatment. Other steps were performed as in Example 1. Sampling and analysis after 10 minutes of reaction showed good copper removal, with a copper concentration of 5.32 mg / L and a copper precipitation rate greater than 93%. Sampling and analysis after another 40 minutes of reaction showed an increase in copper content, reaching 0.11 g / L. This was mainly due to the absence of sulfidation agglomeration, resulting in highly reactive copper sulfide precipitates. Extending the reaction time led to the re-dissolution of the precipitates.

[0096] Comparative Example 2

[0097] Compared to Example 1, the same solution was used as the raw material. The difference was that no surface-treated polysulfides were added, or in other words, the added copper concentrate was not surface-sulfided. Other steps were performed as in Example 1. Sampling and analysis were conducted after 60 minutes of reaction. The copper removal effect was good, with a copper concentration of 2.74 mg / L in the solution after removal and a copper precipitation rate greater than 96%. However, the solution was quite turbid, and the settling performance of the sulfided copper slag was poor, making filtration extremely difficult. This was mainly due to the lack of a polysulfide to induce copper ion precipitation and form large particles.

[0098] Sulfide ions have a strong affinity for copper ions, and the reaction between them is very rapid, forming extremely fine copper sulfide precipitates with very high reactivity. Generally, S... 2- With Cu 2+ The reaction is complete in 15 minutes, at which point the Cu in the solution will be... 2+ The concentration can be significantly reduced, but as time goes on, the fine CuS precipitate dissolves and decomposes back into the solution, causing the Cu concentration in the solution to increase. 2+ The concentration increases, and the precipitate becomes very difficult to filter and settle.

[0099] The applicant discovered in the research that S 2- After being agglomerated by flocculants, the diffusion rate and reactivity are significantly reduced, and the agglomerated S2- The black flocculent particles formed after precipitation with copper ions are significantly larger (see...). Figure 3 The left side shows the precipitate as large agglomerates after the addition of an agglomerating sulfiding agent; the right side shows the precipitate as fine-particle dispersion after the addition of sodium sulfide. Further research revealed that adding surface-sulfided copper concentrate to a copper solution resulted in coarse precipitate particles. This is because the copper concentrate with its polysulfide surface induces the precipitation of copper ions, increasing the particle size of the copper sulfide crystal precipitate. Based on this phenomenon, the applicant proposed a selectively induced agglomeration copper precipitation method, utilizing S... 2- Its high affinity for copper and weak affinity for cobalt enables selective precipitation of metal ions; flocculants are used to bridge and aggregate S 2- This process reduces the diffusion rate and reactivity, passivating the decomposition of copper sulfide precipitates; it utilizes the induced precipitation of polysulfides to promote the crystal growth of copper sulfide precipitate particles; ultimately achieving selective copper precipitation in low-copper raffinate and inducing agglomeration to form large precipitates with good settling properties.

[0100] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

[0101] Furthermore, those skilled in the art will understand that although some embodiments herein include certain features included in other embodiments but not others, combinations of features from different embodiments are intended to be within the scope of this application and form different embodiments. For example, in the foregoing claims, any of the claimed embodiments can be used in any combination. The information disclosed in this background section is intended only to enhance the understanding of the general background of this application and should not be construed as an admission or in any way implying that such information constitutes prior art known to those skilled in the art.

Claims

1. A method for highly efficient and selective copper deposition in cobalt-containing, low-copper raffinate, characterized in that, include: Step 1: The coalescing sulfiding agent solution and the copper polysulfide slurry are added together to the cobalt-containing low-copper raffinate to selectively induce coalescence precipitation reaction. After the reaction, the mixture is thickened to obtain a thick supernatant and a thick underflow. The coalescing sulfiding agent is obtained by adding a flocculant to the sulfiding agent solution for coalescence treatment, and the copper polysulfides are obtained by adding a sulfiding agent to the copper concentrate for surface sulfidation treatment. Step 2: Filter the concentrated underflow to obtain the filtrate and the precipitated wet residue; Step 3: Dehydrate the precipitated wet residue to form precipitated dry residue, and obtain copper sulfide concentrate; The precipitated residue is sent to a sulfide ore processing system to recover copper and cobalt or is recovered as copper sulfide concentrate. The concentrated supernatant and the filtrate are combined to form a copper precipitation liquid for iron removal, and then used to produce crude cobalt hydroxide. The cobalt-containing low-copper raffinate is a solution containing copper, cobalt, iron, and manganese impurity ions produced after leaching and copper extraction during the hydrometallurgical process of copper-cobalt oxide ore; the copper ion concentration in the cobalt-containing low-copper raffinate is 0.01-50 g / L, and the cobalt ion concentration is 0.01-50 g / L. The sulfiding agent includes one or more of sulfide salts, hydrosulfide salts, thiosulfates, hydrogen sulfide, and sulfide minerals; the flocculant includes polyacrylamide-based organic polymers. The copper concentrate includes one or more of copper sulfide, cuprous sulfide, chalcopyrite, and chalcocite. During the surface sulfidation process, water or the cobalt-containing low-copper raffinate is added to form a slurry.

2. The method according to claim 1, characterized in that, The amount of the vulcanizing agent used is 1-10 times the theoretical amount calculated based on the copper ions in the system.

3. The method according to claim 1, characterized in that, The selectively induced coalescence copper deposition reaction is carried out at a temperature of 5-100℃ for a time of 5-360 min.

4. The method according to claim 1, characterized in that, The amount of flocculant added to the coalescing vulcanizing agent solution is 0.5‰-5.0‰.

5. The method according to claim 1, characterized in that, The copper recovery process of the sulfide ore treatment system includes: oxidative roasting, acid leaching, and oxygen pressure leaching of the precipitated dry residue.

6. The method according to claim 1, characterized in that, After the selectively induced coalescence copper precipitation reaction, the copper precipitation rate is not less than 95% and the cobalt precipitation rate is not higher than 2%.

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