A method for selectively depositing copper in copper smelting waste acid

Abstract

The present application provides a method for selectively precipitating copper in waste acid from copper smelting, and relates to the technical field of hydrometallurgy. The method for selectively precipitating copper in waste acid from copper smelting comprises: mixing waste acid from copper smelting with a sulfur-containing organic compound to carry out a copper precipitation reaction, and solid-liquid separation to obtain a copper-removed liquid and a copper precipitation product; the sulfur-containing functional group in the sulfur-containing organic compound comprises one or more of a sulfonic acid group, a thiol group, and a thioether bond. The sulfur-containing functional group in the sulfur-containing organic compound reacts with the copper ions in the reaction system to carry out selective precipitation, which can achieve the capture and removal of copper ions in the waste acid, has the advantages of high copper selectivity, high copper precipitation rate, fast reaction, and mild conditions, and does not carry rhenium elements, which can greatly reduce the loss of rhenium and simplify the process flow.

Description

Technical Field

[0001] The present application relates to the technical field of hydrometallurgy, and in particular to a method for selectively depositing copper in waste acid from copper smelting. Background Art

[0002] A large amount of rhenium resources are contained in the leaching acid during the copper smelting process. Based on the important strategic position of rhenium, the recovery value of rhenium resources in the by-product of copper smelting acid is receiving great attention. However, the leaching acid has high acidity, complex composition, extremely low rhenium content, and high copper and arsenic ion content. It is very difficult to extract and enrich rhenium from it in a targeted manner. In particular, the interference of copper and arsenic ions has always accompanied the rhenium extraction process, making the rhenium extraction process more complicated.

[0003] The methods for extracting rhenium from waste acid that have been industrially applied include solvent extraction, ion exchange and chemical precipitation. The solvent extraction method is simple to operate, has a large extraction capacity and high separation efficiency, but the extraction of rhenium from extremely low rhenium-containing solutions requires operation under high O / A ratio conditions, and a large amount of stripping residue is produced during stripping, which is difficult to handle, resulting in a rhenium loss of 45% to 55%. The ion exchange method has a simple process, is environmentally friendly and highly selective, but has limited regeneration times and adsorption capacity, and has high sulfuric acid and arsenic content, which can easily cause poisoning and inactivation of ion exchange resins. The chemical precipitation method has the advantages of simple process and low equipment requirements. It uses the precipitation reaction of specific ions for targeted extraction and enrichment, making its operation more flexible. The emergence of new precipitants has also re-attracted attention to the chemical precipitation method.

[0004] In the current process of extracting rhenium from waste acid by chemical precipitation, sodium sulfide, sodium hydrosulfide, and sodium thiosulfate are often used as precipitants. However, due to the chemical properties of these precipitants themselves, copper and rhenium in the waste acid are precipitated at the same time, copper is enriched in the rhenium-rich slag, and arsenic is also enriched. The selective leaching of rhenium is difficult, the process is long, and the recovery rate is low.

[0005] Chinese patent CN103773963B discloses a method for efficiently and controllably recovering copper-rhenium from waste acid from copper smelting. The method uses flocculants and thiosulfate to precipitate copper-rhenium together. The rhenium precipitation rate is over 98%, but the copper precipitation rate is also over 95%, and about 10% of arsenic is entrained in the precipitate, so the selectivity is not ideal.

[0006] Chinese patent CN114671485A discloses a method for removing copper, iron and mercury ions from wastewater by adsorbing and removing them using a heavy metal ion-specific adsorbent; a bacterial cellulose membrane is prepared by modifying bacterial cellulose with functional molecules methionine, cysteine ​​and 2-methylthio-ethanol, and the copper ions are adsorbed and removed from the wastewater by using the specific soft acid-soft base interaction between methionine and copper ions; the method has a good adsorption and removal effect in a prepared wastewater system with a pH of 3 and a nitrate anion, but still cannot reflect the adsorption and removal situation of real wastewater, and cannot determine its copper removal effect in anions containing sulfate, chloride, perrhenate, arsenate, molybdate and other ions.

[0007] Based on this, how to selectively remove copper in a high-acid complex solution system, separate copper and rhenium, and eliminate the interference of copper ions on downstream processes is a problem that needs to be solved urgently. Summary of the invention

[0008] The purpose of the present application is to provide a method for selectively depositing copper in copper smelting waste acid to solve the above-mentioned problems.

[0009] To achieve the above objectives, the present application provides a method for selectively depositing copper in copper smelting waste acid, comprising:

[0010] Copper smelting waste acid and sulfur-containing organic compounds are mixed to undergo copper precipitation reaction, and solid-liquid separation is performed to obtain copper-removed liquid and copper precipitation products;

[0011] The sulfur-containing functional groups in the sulfur-containing organic compound include one or more of sulfonic acid groups, mercapto groups, and thioether bonds.

[0012] Optionally, the sulfur-containing organic compound includes one or more of aminobenzenesulfonic acid, 2-sulfonate terephthalic acid monosodium salt, L-methionine, L-cysteine, 4-aminothiophenol, and 4-nitrothiophenol.

[0013] Optionally, the sulfur-containing organic compound includes one or more of L-cysteine, 4-aminothiophenol, and 4-nitrothiophenol.

[0014] Optionally, the temperature of the copper precipitation reaction is 10°C-100°C, and the time is 10min-1440min.

[0015] Optionally, the hydrogen ion concentration of the copper smelting waste acid is 0.01g / L-5g / L.

[0016] Optionally, the mass ratio of the sulfur-containing organic compound to the copper ion content in the copper smelting waste acid is (2-100):1.

[0017] Optionally, the mixture further comprises an auxiliary agent;

[0018] The auxiliary agent includes one or more of ethanol, methanol, sodium hydroxide solution and ammonia water.

[0019] Optionally, the ratio of the volume usage of the auxiliary agent to the volume usage of the copper smelting waste acid is 1:(1-50).

[0020] Optionally, the copper-removed liquid is used to prepare rhenium.

[0021] Optionally, the copper precipitation product is returned to the copper smelting system.

[0022] Compared with the prior art, the beneficial effects of this application include:

[0023] The present application provides a method for selectively precipitating copper in copper smelting waste acid. The sulfur-containing functional groups in the sulfur-containing organic compound react with the copper ions in the reaction system to form a stable complex by utilizing the coordination effect between the sulfur-containing organic compound and the metal ions, thereby selectively precipitating and removing copper from a complex copper smelting waste acid solution. The method has the advantages of high copper selectivity, high copper precipitation rate, rapid reaction, and mild conditions, and does not carry over the rhenium element, which can greatly reduce the loss of rhenium and simplify the process flow. The method is simple to operate, has low energy consumption, a short process flow, good selectivity, safety and environmental protection, and high copper precipitation efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope of the present application.

[0025] Figure 1 This is a flow chart of the method for selective copper precipitation in copper smelting waste acid provided in Example 1. DETAILED DESCRIPTION

[0026] As used herein:

[0027] "Prepared from" is synonymous with "comprising." As used herein, the terms "comprising," "including," "having," "containing," or any other variation thereof, are intended to cover a non-exclusive inclusion. For example, a composition, process, method, article, or apparatus that comprises the listed elements is not necessarily limited to only those elements but may include other elements not expressly listed or inherent to such composition, process, method, article, or apparatus.

[0028] The conjunction "consisting of excludes any unspecified element, step, or component. If used in a claim, this phrase renders the claim closed-ended so that it does not include materials other than those described, except for conventional impurities associated therewith. When the phrase "consisting of" appears in a clause of the body of a claim rather than immediately following the subject matter, it limits only the elements described in that clause; other elements are not excluded from the claim as a whole.

[0029] When an amount, concentration, or other value or parameter is expressed as a range, a preferred range, or a range defined by a series of upper preferred values ​​and lower preferred values, this should be understood as specifically disclosing all ranges formed by any pairing of any range upper limit or preferred value with any range lower limit or preferred value, regardless of whether the range is disclosed separately. For example, when a range of "1 to 5" is disclosed, the described range should be interpreted as including ranges "1 to 4", "1 to 3", "1 to 2", "1 to 2 and 4 to 5", "1 to 3 and 5", etc. When a numerical range is described in this article, unless otherwise stated, the range is intended to include its end values ​​and all integers and fractions within the range.

[0030] In these examples, parts and percentages are by mass unless otherwise indicated.

[0031] "Parts by mass" refers to the basic unit of measurement for expressing the mass ratio of multiple components. 1 part can represent any unit mass, such as 1g or 2.689g. If we say that the mass of component A is a parts and the mass of component B is b parts, it means the ratio of the mass of component A to the mass of component B is a:b. Alternatively, it means that the mass of component A is aK and the mass of component B is bK (K is an arbitrary number, indicating a multiple factor). It should not be misunderstood that, unlike the mass parts, the sum of the mass of all components is not limited to 100 parts.

[0032] “And / or” is used to indicate that one or both of the stated situations may occur, for example, A and / or B includes (A and B) and (A or B).

[0033] It should be noted that the waste acid from copper smelting is a high-acid complex solution system, in which the hydrogen ion concentration is about 0.01g / L-5g / L, and it contains a variety of impurity elements such as copper, rhenium, arsenic, aluminum, silicon, phosphorus, sulfur, manganese, iron, calcium, cadmium, zinc, nickel, magnesium, chromium, bismuth, etc. Conventional precipitants are prone to co-precipitation with copper, rhenium, and arsenic, resulting in the loss of rhenium, and are unable to specifically remove copper; in a high-acid complex solution system, the interference of multiple impurity elements may cause the functional adsorbent to become functionally inactivated, and it cannot effectively adsorb copper.

[0034] The present application provides a method for selectively depositing copper in copper smelting waste acid, comprising:

[0035] Copper smelting waste acid and sulfur-containing organic compounds are mixed to undergo copper precipitation reaction, and solid-liquid separation is performed to obtain copper-removed liquid and copper precipitation products;

[0036] In some embodiments, the element composition and content of the copper precipitation product are 27% copper, 26% sulfur, 0.01% aluminum, 0.01% manganese, 0.03% iron, 0.02% silicon, and 0.03% phosphorus; rhenium and arsenic are not entrained in the copper precipitation product, and the content of other impurity elements is less than 0.03%, indicating that the method provided in the present application has a high selectivity and removal rate for copper ions, and well realizes the separation of copper and rhenium;

[0037] The sulfur-containing functional groups in the sulfur-containing organic compound include one or more of sulfonic acid groups, mercapto groups, and thioether bonds.

[0038] It should be noted that the sulfur-containing organic compound provided in the present application can specifically bind to copper in a highly acidic complex solution to produce a precipitate.

[0039] In some embodiments, the sulfur-containing organic compound includes one or more of aminobenzenesulfonic acid, 2-sulfonate terephthalic acid monosodium salt, L-methionine, L-cysteine, 4-aminothiophenol, and 4-nitrothiophenol.

[0040] In some embodiments, the sulfur-containing organic compound includes one or more of L-cysteine, 4-aminothiophenol, and 4-nitrothiophenol.

[0041] It should be noted that when the sulfur-containing organic compounds include L-cysteine, 4-aminothiophenol, and 4-nitrothiophenol, the sulfur in the thiol group specifically binds to copper ions, the reaction is rapid, the product is stable, the anti-interference ability is stronger, and the solution has a wide range of applications.

[0042] In some embodiments, the copper precipitation reaction is carried out at a temperature of 10°C-100°C and a time of 10 min-1440 min.

[0043] Optionally, the temperature of the copper precipitation reaction can be 10°C, 20°C, 30°C, 40°C, 50°C, 60°C, 70°C, 80°C, 90°C, 100°C or any value between 10°C-100°C, and the time can be 10min, 100min, 200min, 300min, 400min, 500min, 600min, 700min, 800min, 900min, 1000min, 1100min, 1200min, 1400min, 1400min, 1440min or any value between 10min-1440min.

[0044] In some embodiments, the copper smelting waste acid has a hydrogen ion concentration of 0.01 g / L-5 g / L.

[0045] Optionally, the hydrogen ion concentration of the copper smelting waste acid can be 0.01g / L, 0.1g / L, 1g / L, 2g / L, 3g / L, 4g / L, 5g / L or any value between 0.01g / L-5g / L.

[0046] It should be noted that the hydrogen ion concentration of copper smelting waste acid is 0.01g / L-5g / L, which is a high acid condition. At this concentration, ordinary inorganic precipitants and other adsorbents are difficult to achieve efficient selective capture and removal of copper. The sulfur-containing organic compounds provided in this application can selectively coordinate with copper ions under this condition to produce copper complex precipitates, thereby removing copper ions in the waste acid solution.

[0047] In some embodiments, the mass ratio of the sulfur-containing organic compound to the copper ion content in the copper smelting waste acid is (2-100):1.

[0048] Optionally, the mass ratio of the sulfur-containing organic compound to the copper ion content in the copper smelting waste acid can be 2:1, 5:1, 10:1, 20:1, 30:1, 40:1, 50:1, 60:1, 70:1, 80:1, 90:1, 100:1 or any value between (2-100):1.

[0049] It should be noted that when the mass ratio of the sulfur-containing organic compound to the copper ion content in the copper smelting waste acid is (2-100):1, the reaction can proceed rapidly and promote the reaction equilibrium to develop in the direction of forming precipitation, thereby efficiently and selectively precipitating copper.

[0050] In some embodiments, the mixing further comprises an adjuvant;

[0051] The auxiliary agent includes one or more of ethanol, methanol, sodium hydroxide solution and ammonia water.

[0052] It should be noted that auxiliary agents can adjust the ion concentration and state in the system and promote the reaction.

[0053] In some embodiments, the ratio of the volume of the auxiliary agent to the volume of the waste acid solution is 1:(1-50).

[0054] Optionally, the ratio of the volume usage of the auxiliary agent to the volume usage of the waste acid solution can be 1:1, 1:5, 1:10, 1:20, 1:30, 1:40, 1:50 or any value between 1:(1-50).

[0055] It should be noted that when the ratio of the volume of the auxiliary agent to the volume of the dirty acid solution is 1: (1-50), the ion concentration and state in the system can be adjusted to promote the reaction.

[0056] In some embodiments, the copper-removed solution is used to prepare rhenium.

[0057] It should be noted that the liquid after copper removal can be used as a short-process raw material for rhenium preparation. In the downstream process, after the interference of copper ions is eliminated from the waste acid solution, the separation effect of rhenium and arsenic can be significantly improved, thereby improving the production efficiency of the rhenium preparation process.

[0058] In some embodiments, the copper precipitation product is returned to the copper smelting system.

[0059] It should be noted that the copper precipitation product is returned to the copper smelting system and can enter the copper smelting production section to be used as a copper-containing raw material, further improving resource utilization.

[0060] The embodiments of the present application will be described in detail below in conjunction with specific examples, but it will be appreciated by those skilled in the art that the following examples are only used to illustrate the present application and should not be considered as limiting the scope of the present application. If specific conditions are not specified in the examples, they are carried out according to normal conditions or the conditions recommended by the manufacturer. If the manufacturer is not specified in the reagents or instruments used, they are all conventional products that can be purchased commercially.

[0061] Example 1

[0062] This embodiment provides a method for selectively precipitating copper in copper smelting waste acid, wherein the copper smelting waste acid is flue gas elution waste acid in the copper smelting process of a certain factory, which contains 30 mg / L copper, 20 mg / L rhenium, 5 g / L arsenic, and a hydrogen ion concentration of 1.3 g / L;

[0063] The specific steps are as follows:

[0064] Grind and prepare 2-sulfonate terephthalic acid monosodium salt and 4-aminothiophenol in a mass ratio of 1:2 to obtain a sulfur-containing organic compound A (organic precipitant);

[0065] Weigh 100 mg of sulfur-containing organic compound A and add it to 100 mL of waste acid, add 15 mL of ammonia water, stir at 60°C for 30 min, and then filter to obtain a black solid and waste acid copper precipitation liquid;

[0066] The black solids are returned to the copper smelting system;

[0067] The waste acid copper precipitation liquid is used as a short-process raw material for the preparation of rhenium.

[0068] The specific process of selective copper precipitation in copper smelting waste acid is as follows: Figure 1 shown.

[0069] The prepared waste acid copper precipitation solution contains 0.09 mg / L copper, 19.89 mg / L rhenium, 5 g / L arsenic, and the copper precipitation rate is 99.7%.

[0070] Example 2

[0071] This embodiment provides a method for selectively precipitating copper in copper smelting waste acid, wherein the copper smelting waste acid is flue gas elution waste acid in the copper smelting process of a certain factory, wherein copper is 200 mg / L, rhenium is 10 mg / L, arsenic is 4 g / L, and hydrogen ion concentration is 4 g / L;

[0072] The specific steps are as follows:

[0073] Grind 4-nitrothiophenol and 4-aminothiophenol in a ratio of 1:1 to obtain a sulfur-containing organic compound B (organic precipitant);

[0074] Weigh 500 mg of sulfur-containing organic compound B and add it to 100 mL of waste acid, add 20 mL of sodium hydroxide aqueous solution (10%), stir at 70° C. for 10 min, and then filter to obtain a black solid and waste acid copper precipitation liquid.

[0075] The prepared waste acid copper precipitation solution contains 0.14 mg / L copper, 13 mg / L rhenium, 4 g / L arsenic, and the copper precipitation rate is 99.9%.

[0076] Example 3

[0077] This embodiment provides a method for selectively precipitating copper in copper smelting waste acid, wherein the copper smelting waste acid is flue gas elution waste acid in the copper smelting process of a certain factory, containing 17 mg / L copper, 80 mg / L rhenium, 9 g / L arsenic, and a hydrogen ion concentration of 2 g / L;

[0078] The specific steps are as follows:

[0079] L-cysteine ​​and 4-nitrothiophenol were ground and prepared in a ratio of 3:2 to obtain a sulfur-containing organic compound C (organic precipitant);

[0080] Weigh 300 mg of sulfur-containing organic compound C and add it to 100 mL of waste acid, add 5 mL of ethanol and 5 mL of sodium hydroxide aqueous solution (10%), stir at 40° C. for 4 h, and then filter to obtain a black solid and waste acid copper precipitation liquid.

[0081] The prepared waste acid copper precipitation solution contained 0.31 mg / L copper, 79.7 mg / L rhenium, 8.7 g / L arsenic, and a copper precipitation rate of 98.2%.

[0082] Example 4

[0083] This embodiment provides a method for selectively precipitating copper in copper smelting waste acid, wherein the copper smelting waste acid is flue gas elution waste acid in the copper smelting process of a certain factory, containing 2g / L copper, 1.25g / L arsenic, and a hydrogen ion concentration of 2.5g / L;

[0084] The specific steps are as follows:

[0085] L-methionine and 4-aminothiophenol were ground and prepared in a ratio of 3:2 to obtain a sulfur-containing organic compound D (organic precipitant);

[0086] Weigh 1 g of sulfur-containing organic compound D and add it to 100 mL of waste acid, add 30 mL of aqueous ammonia, stir at 50°C for 4 h, and then filter to obtain a black solid and waste acid copper precipitation liquid.

[0087] The prepared waste acid copper precipitation solution contained 0.42 mg / L copper and 1.25 g / L arsenic, and the copper precipitation rate was 99.9%.

[0088] Comparative Example 1

[0089] This comparative example provides a method for precipitating copper in waste acid from copper smelting. The difference from Example 1 is that the precipitant in this comparative example is sodium thiosulfate among inorganic sulfides, and 1% flocculant is added to assist in collecting the precipitate. Other conditions are consistent with Example 1.

[0090] The prepared waste acid copper precipitation solution contains 0.05 mg / L copper, 0.07 mg / L rhenium, 4.45 g / L arsenic, with a copper precipitation rate of 99.8%, a rhenium precipitation rate of 99.7%, and an arsenic precipitation rate of 11%.

[0091] Comparative Example 2

[0092] This comparative example provides a method for precipitating copper in waste acid from copper smelting. The difference from Example 1 is that the precipitant in this comparative example is 2-methylimidazole, which is a sulfur-free organic compound, and the other conditions are consistent with those in Example 1.

[0093] The prepared waste acid copper precipitation solution contains 29.8 mg / L copper, 19.9 mg / L rhenium, and 5 g / L arsenic. Within the range of test error, it can be preliminarily determined that 2-methylimidazole cannot precipitate copper, rhenium, and arsenic in a high-acid environment.

[0094] It can be seen from the above embodiments and comparative examples that although inorganic sulfides have a significant copper precipitation effect, rhenium and arsenic will undergo a co-precipitation reaction with copper, and copper cannot be specifically removed. Copper, rhenium and arsenic are difficult to be separated efficiently, which increases the downstream process; sulfur-free organic compounds are difficult to react with copper ions under high acid conditions to form stable precipitates, and the copper removal effect is poor; while sulfur-containing organic compounds can react with copper ions under high acid conditions to form stable products, and the specific groups they contain, such as sulfonic acid groups, thiol groups, and thioether bonds, can undergo specific coordination reactions with copper, thereby improving their anti-interference ability in high acid complex solutions, and the copper precipitation product does not carry rhenium and arsenic, thereby achieving efficient and selective removal of copper.

[0095] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit it. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application.

[0096] In addition, those skilled in the art will appreciate that, although some embodiments herein include certain features included in other embodiments but not other features, the combination of features of different embodiments is meant to be within the scope of the present application and form different embodiments. For example, in the above claims, any one of the claimed embodiments may be used in any combination. The information disclosed in this background technology section is intended only to deepen the understanding of the overall background technology of the present application and should not be regarded as an admission or in any form of implication that the information constitutes prior art known to those skilled in the art.

Claims

1. A method for selectively depositing copper in copper smelting waste acid, characterized in that: include: Copper smelting waste acid and sulfur-containing organic compounds are mixed to undergo copper precipitation reaction, and solid-liquid separation is performed to obtain copper-removed liquid and copper precipitation products; The sulfur-containing organic compound includes one or more of aminobenzenesulfonic acid, 2-sulfonate terephthalic acid monosodium salt, L-methionine, L-cysteine, 4-aminothiophenol, and 4-nitrothiophenol; The temperature of the copper precipitation reaction is 10°C-100°C; The mass ratio of the sulfur-containing organic compound to the copper ion content in the copper smelting waste acid is (2-100): 1; The hydrogen ion concentration of the copper smelting waste acid is 0.01g / L-5g / L; The copper-removed liquid is used for preparing rhenium.

2. The method for selectively depositing copper in copper smelting waste acid according to claim 1, characterized in that: The sulfur-containing organic compound includes one or more of L-cysteine, 4-aminothiophenol, and 4-nitrothiophenol.

3. The method for selective copper precipitation in copper smelting waste acid according to claim 1, characterized in that: The copper precipitation reaction time is 10min-1440min.

4. The method for selective copper precipitation in copper smelting waste acid according to claim 1, characterized in that: The mixture also includes an adjuvant; The auxiliary agent includes one or more of ethanol, methanol, sodium hydroxide solution and ammonia water.

5. The method for selectively depositing copper in copper smelting waste acid according to claim 4, characterized in that: The ratio of the volume usage of the auxiliary agent to the volume usage of the copper smelting waste acid is 1:(1-50).

6. The method for selectively depositing copper in copper smelting waste acid according to any one of claims 1 to 5, characterized in that: The copper precipitation product is returned to the copper smelting system.

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