Copper cementing agent, its preparation method, use and method for treating copper-containing waste liquid

Abstract

The present application provides a copper precipitation coagulant, a preparation method, uses and a method for treating copper-containing waste liquid. The copper precipitation coagulant comprises M y CO x S 3‑x , M(OH) z and water, wherein M is at least one of Na, K and Mg, 0≤x<3, y is 1 or 2, and z is 2 or 1. Thus, the copper precipitation coagulant has obvious effects, can coagulate copper-containing precipitates in the copper-containing waste liquid into copper-containing particles with larger particle sizes, and can directly perform pressure filtration to separate the copper-containing particles, so that the use of a flocculant PAM in the copper recovery process is eliminated, thereby simplifying the treatment process of the copper-containing waste liquid, reducing the treatment cost of the copper-containing waste liquid, and improving the copper recovery efficiency.

Description

Technical Field

[0001] This invention relates to the technical field of wastewater treatment, specifically to copper-precipitating coagulants, their preparation methods, uses, and methods for treating copper-containing wastewater. Background Technology

[0002] The electrolytic copper and electroplating copper industries are among the most polluting, producing wastewater containing organic matter, copper, and inorganic salts, posing significant risks to human health and the environment. However, copper-containing wastewater also contains high-value metals like copper, representing a valuable secondary resource. Therefore, from an environmental protection and resource recycling perspective, it is essential to recover and reuse copper from copper-containing wastewater. Common methods for recovering copper-containing wastewater include electrolysis and chemical precipitation. Electrolysis requires an acidic solution, and its efficiency drops significantly when the copper ion concentration falls below 10 g / L. Therefore, it is often combined with membrane concentration and chemical precipitation technologies to recover copper from the solution. Chemical precipitation primarily uses sodium hydroxide to precipitate copper ions from the wastewater, generating precipitates mainly composed of copper hydroxide or basic copper sulfate. Filtering these precipitates yields valuable copper-containing products. However, the very fine (near nanometer scale) particles of the precipitates are difficult to filter, significantly impacting the treatment efficiency of the copper-containing wastewater. Summary of the Invention

[0003] This invention aims to at least partially solve one of the technical problems in related technologies. Therefore, one object of this invention is to provide a copper-laden coagulant that can effectively separate copper elements from copper-containing wastewater, thereby improving the treatment efficiency of copper-laden wastewater.

[0004] In one aspect of the invention, a copper plating coagulant is provided. According to an embodiment of the invention, the copper plating coagulant comprises M y CO x S 3-x M(OH) z And water, wherein M is at least one of Na, Ka, and Mg, 0 ≤ x < 3, y is 1 or 2, and z is 2 or 1. Therefore, the effect of the copper precipitating coagulant is significant: due to M in the copper precipitating coagulant... y CO x S 3-xThe sulfur in the copper-containing wastewater exhibits a strong interaction with the copper, and the copper-laden coagulant is readily soluble in water. This interaction between the sulfur-containing groups and the copper precipitate creates a bridging effect, binding one or more particles together around the coagulant. This rapid aggregation of particles leads to a significant increase in particle size, effectively coagulating the copper precipitate in the wastewater into larger copper-containing particles. These particles can then be directly separated by pressure filtration without the need for PAM (polyacrylamide), thus eliminating the use of PAM flocculant in copper recovery. This simplifies the treatment process for copper-laden wastewater, reduces treatment costs, and improves copper recovery efficiency. Furthermore, the separated copper-laden product has high economic value. The coagulant does not contain iron, aluminum, or other metal cations, and the main agglomerative component is a sulfur-containing anion group. Therefore, no metal impurities are introduced into the product, further enhancing its economic value. Additionally, the sulfur in the product can be converted into sulfuric acid during smelting, further increasing its economic value.

[0005] According to an embodiment of the present invention, the copper plating coagulant further includes at least one of diethyl ether and M2CO3.

[0006] According to an embodiment of the present invention, 0 ≤ x ≤ 1.

[0007] According to an embodiment of the present invention, based on the total mass of the copper plating coagulant, the copper plating coagulant comprises, by mass percentage: 30% to 60% M y CO x S 3-x 2%–8% M(OH) z ; 0.5%–1.5% ether; 0.5%–1.5% M2CO3; and 29%–67% water.

[0008] According to an embodiment of the present invention, the copper plating coagulant comprises: 40% to 50% M y CO x S 3-x 4%–6% M(OH) z ; 0.8% to 1.2% ether; 0.8% to 1.2% M2CO3; and 41.6% to 54.4% water.

[0009] According to an embodiment of the present invention, based on the total mass of the copper plating coagulant, the copper plating coagulant further includes, by mass percentage: 0-5% N2S, where N is at least one of Na and K.

[0010] In another aspect, the present invention provides a method for preparing the aforementioned copper plating coagulant. According to an embodiment of the present invention, the method for preparing the copper plating coagulant includes: providing a raw material mixture solution, said raw material mixture solution comprising M(OH)₂. z The mixture comprises N₂S and water, wherein M is at least one of Na, Li, Ka, and Mg, N is at least one of Na and Ka, and z is 2 or 1; carbon disulfide gas is introduced into the raw material mixture solution, and the copper precipitating coagulant is obtained after the reaction. Therefore, the copper precipitating coagulant prepared by the above method contains M... y CO x S 3-x The sulfur in the solution has a strong interaction with the copper in the copper-containing wastewater, resulting in an interaction between the sulfur-containing groups and the copper-containing precipitate. This effectively agglomerates the copper-containing precipitate into larger copper-containing particles, which can then be directly separated by pressure filtration. This avoids the use of flocculant PAM (polyacrylamide), simplifies the treatment process of copper-containing wastewater, reduces treatment costs, and improves copper recovery efficiency. At the same time, the above preparation method is simple, mild, uses inexpensive raw materials, and has low preparation costs, thus greatly reducing the treatment cost of copper-containing wastewater.

[0011] According to an embodiment of the present invention, the raw material mixture further includes at least one of diethyl ether and M2CO3.

[0012] According to an embodiment of the present invention, based on the total mass of the raw material mixture solution, the raw material mixture solution comprises, by mass percentage: 25% M(OH) z ; 1% ether; 1% M2CO3; 30% N2S; and the balance water.

[0013] According to an embodiment of the present invention, the molar amount of carbon disulfide is related to the amount of M(OH) in the raw material solution. z The ratio of the molar amounts of N2S to the total molar amounts of N2S is 2.2:3 to 2.4:3.

[0014] In another aspect, the present invention provides an application of the aforementioned copper-coagulant in the treatment of copper-containing wastewater. This effectively improves the efficiency of copper recovery from copper-containing wastewater and reduces recovery costs.

[0015] In another aspect, the present invention provides a method for treating copper-containing wastewater using the aforementioned copper-precipitating coagulant. According to an embodiment of the present invention, the method for treating copper-containing wastewater using the copper-precipitating coagulant includes: adjusting the pH of the copper-containing wastewater to alkaline; adding the copper-precipitating coagulant to the copper-containing wastewater and stirring to obtain a mixture of copper-containing particles; filtering the mixture of copper-containing particles to obtain copper-containing particles and treated wastewater. Therefore, the method for treating copper-containing wastewater is simple, operates under mild conditions, has low implementation costs, and exhibits high copper recovery efficiency.

[0016] According to an embodiment of the present invention, the particle size of the copper-containing particles is 40 to 100 micrometers.

[0017] According to an embodiment of the present invention, the filtration uses a filter cloth with a mesh size of 200 to 800. Attached Figure Description

[0018] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0019] Figure 1 This is a schematic diagram illustrating the working principle of the copper-plating flocculant in one embodiment of the present invention;

[0020] Figure 2 This is a particle size distribution diagram of copper-containing particles before and after treatment with copper-precipitating flocculant in Example 1;

[0021] Figure 3 This is a particle size distribution diagram of copper-containing particles before and after treatment with copper flocculant in Example 2. Detailed Implementation

[0022] The present invention will be explained below with reference to embodiments. Those skilled in the art will understand that the following embodiments are for illustrative purposes only and should not be considered as limiting the scope of the invention. Where specific techniques or conditions are not specified in the embodiments, they are performed according to the techniques or conditions described in the literature in the field or according to the product instructions. Reagents or instruments whose manufacturers are not specified are all conventional products that can be obtained commercially.

[0023] The present invention will now be described with reference to specific embodiments. It should be noted that these embodiments are merely descriptive and do not limit the present invention in any way.

[0024] In one aspect of the invention, a copper plating coagulant is provided. According to an embodiment of the invention, the copper plating coagulant comprises M y CO x S 3-x M(OH) zAnd water, wherein M is at least one of Na, Ka, and Mg, 0 ≤ x < 3, y is 1 or 2, and z is 2 or 1. Therefore, the effect of the copper precipitating coagulant is significant: due to M in the copper precipitating coagulant... y CO x S 3-x The sulfur in the copper-containing wastewater has a strong interaction with the copper in the copper-containing wastewater, and the copper-containing coagulant is easily soluble in water, resulting in an interaction force between the sulfur-containing groups and the copper-containing precipitate. This interaction force acts like a bridge, binding one or more particles together around the copper-containing coagulant. In a short time, several or more particles are agglomerated, causing the particle size to increase rapidly. That is, the copper-containing precipitate in the copper-containing wastewater is agglomerated into copper-containing particles with a larger particle size, which can be directly separated by pressure filtration without the need to add PAM (polyacrylamide). This eliminates the use of flocculant PAM in the copper recovery process, thereby simplifying the treatment process of copper-containing wastewater, reducing the treatment cost of copper-containing wastewater, and improving the efficiency of copper recovery. Moreover, the separated copper-containing products have high economic value. This copper-coagulating agent does not contain iron, aluminum, or other metal cations, and the main agglomerating agent is a sulfur-containing anionic group. Therefore, no metal impurity ions are introduced into the product, which helps to increase the economic value of the separated copper-containing products. Furthermore, the sulfur in the product can be converted into sulfuric acid during smelting, further enhancing the product's high economic value; furthermore, M(OH) z Provide a certain alkaline environment for the copper plating coagulant to prevent M y CO x S 3-x It is decomposed to produce hydrogen sulfide.

[0025] According to some embodiments of the present invention, the copper plating coagulant further includes at least one of diethyl ether and M2CO3. Specifically, diethyl ether is used to accelerate the formation of M2CO3 during the synthesis of the copper plating coagulant. x S 3-x The catalyst improves the efficiency of preparing copper precipitating coagulant; during the process of pressure filtration to separate copper particles, M2CO3 can make the flow rate of the filtrate faster, resulting in better dehydration of copper particles (or copper sludge) and less water content in the obtained copper particles (or copper sludge).

[0026] In some embodiments of the present invention, M y CO x S 3-x M(OH) z The metal element M in M₂CO₃ is independent of the other two elements; that is, the metal element M in all three elements can be the same or different. For example, M... y CO x S 3-x The element M in M(OH) is sodium. zThe metal M in M2CO3 is potassium, and the metal M in M2CO3 is sodium; or the element M in all three materials is sodium or potassium.

[0027] In some embodiments of the present invention, M is preferably at least one of Na or K, which can ensure the presence of MCO in the copper plating coagulant. x S 3-x The good water solubility of solutes such as MOH and M2CO3 prevents precipitation or crystallization, ensuring the good chemical stability of the copper precipitating coagulant and thus promoting its coagulation effect. Choosing other cations will affect the water solubility of the coagulant, thereby impacting its coagulation effect and ultimately affecting the copper separation from copper-containing wastewater.

[0028] According to some embodiments of the present invention, 0≤x≤1, M y CO x S 3-x For M y CS3 or M y COS2. Both of these substances exhibit good coagulation effects on copper-containing precipitates and are easier to obtain during the preparation process.

[0029] According to some embodiments of the present invention, based on the total mass of the copper plating coagulant, the copper plating coagulant comprises, by mass percentage: 30% to 60% (e.g., 30%, 33%, 35%, 38%, 40%, 42%, 45%, 48%, 50%, 52%, 55%, 57%, 60%, etc.) of M. y CO x S 3-x ; 2% to 8% (e.g., 2%, 3%, 4%, 5%, 6%, 7%, 8%, etc.) of M(OH) z ; 0.5%–1.5% (e.g., 0.5%, 0.7%, 0.9%, 1.0%, 1.1%, 1.2%, 1.3%, 1.4%, 1.5%, etc.) of diethyl ether; 0.5%–1.5% (e.g., 0.5%, 0.7%, 0.9%, 1.0%, 1.1%, 1.2%, 1.3%, 1.4%, 1.5%, etc.) of M2CO3; and 29%–67% water. Among these, M... y CO x S 3-x As the main coagulating component of copper plating coagulant, if M y CO x S 3-x The concentration is too low, and the MCO concentration per unit volume is too low. x S 3-x The concentration is relatively low, which is not conducive to the aggregation of copper-containing precipitates into large particles; if M y CO x S 3-xIf the concentration is too high, it may cause excessively high local sulfur content when added to the reaction vessel, posing a risk of hydrogen sulfide precipitation; M y CO x S 3-x A content of 30%–60% effectively coagulates copper precipitates into large-diameter copper-containing particles while minimizing the risk of hydrogen sulfide precipitation within the reaction vessel, thus improving operational safety. M(OH) z Its main purpose is to provide raw materials and an alkaline environment for the synthesis of copper precipitating coagulants. The alkaline environment is mainly to prevent hydrogen sulfide from overflowing from the solution during and after the synthesis process. Therefore, if it is an alkaline solution, M(OH) z If the concentration is too low, the pH of the solution after synthesizing the copper precipitating coagulant will be low, significantly increasing the risk of hydrogen sulfide precipitation; if the alkali concentration is too high, it will increase the cost of preparing the copper precipitating coagulant, and excessive hydroxide ions may also cause the copper-containing precipitate to dissolve back into the aqueous solution, reducing the particle size of the copper-containing precipitate and hindering its coagulation; M(OH) z The content of [agent name] is 2%–8%, providing a certain alkaline environment for the aqueous solution of the copper precipitant, preventing the precipitation of hydrogen sulfide, and simultaneously enhancing the coagulation effect of copper-containing precipitates, which is beneficial for obtaining large-diameter copper-containing particles. Diethyl ether is used to accelerate the formation of M [agent name] during the synthesis and preparation of the copper precipitant. y CO x S 3-x The catalyst, M2CO3, has a limited effect on accelerating the reaction if the ether concentration is low; conversely, a high ether concentration carries the risk of ether volatilization. During the pressure filtration separation of copper-containing particles, M2CO3 increases the flow rate of the filtrate, resulting in better dehydration of the copper-containing particles (or copper sludge) and lower water content. However, if the M2CO3 concentration is too low, its promoting effect on the pressure filtration of copper-containing sludge is weak; conversely, an excessively high concentration increases processing costs. An M2CO3 content of 0.5%–1.5% aims to improve the dehydration of copper-containing particles while minimizing the overall cost of the copper-coagulant.

[0030] According to some embodiments of the present invention, the copper plating coagulant comprises: 40% to 50% M y CO x S 3-x 4%–6% M(OH) z The mixture contains 0.8%–1.2% diethyl ether, 0.8%–1.2% M2CO3, and 41.6%–54.4% water. The copper precipitating coagulant prepared in the above proportions exhibits superior copper precipitation and coagulation effects.

[0031] According to some embodiments of the present invention, based on the total mass of the copper plating coagulant, the copper plating coagulant further includes, by mass percentage: 0-5% N₂S, where N is at least one of Na and Ka. Thus, the copper plating coagulant contains S.2- In the process of treating copper-containing wastewater, S 2- It can further combine with copper ions in the supernatant, thereby reducing the copper ion content in the supernatant and increasing the copper content in the copper mud. In addition, the interaction between copper and sulfur is much greater than the interaction between copper and organic matter. Therefore, the presence of N2S can give this coagulant a certain ability to break the complexation between copper and organic matter, i.e., complex breaking ability, thereby enhancing its ability to coagulate copper.

[0032] In another aspect, the present invention provides a method for preparing the aforementioned copper plating coagulant. According to an embodiment of the present invention, the method for preparing the copper plating coagulant includes:

[0033] S100: Provides a raw material mixture solution, which includes M(OH) z The mixture contains N₂S and water, wherein M is at least one of Na, Li, Ka, and Mg, N is at least one of Na and Ka, and z is 2 or 1.

[0034] According to some embodiments of the present invention, the raw material mixture further includes at least one of diethyl ether and M2CO3. Diethyl ether is used to accelerate the formation of M2CO3 during the synthesis of the copper plating coagulant. y CO x S 3-x The catalyst, thereby improving the efficiency of preparing copper plating coagulant, means that compared to the reaction without diethyl ether, the addition of diethyl ether produces M... y CO x S 3-x The flow rate is greatly improved; during the process of pressure filtration to separate copper-containing particles, M2CO3 can make the flow rate of the filtrate faster, resulting in better dehydration of copper-containing particles (or copper sludge) and less water content in the obtained copper-containing particles (or copper sludge).

[0035] According to some embodiments of the present invention, based on the total mass of the raw material mixture solution, the raw material mixture solution comprises, by mass percentage: 20%-30% M(OH). z The mixture comprises: 0.5%-1.5% diethyl ether; 0.5%-1.5% M2CO3; 25%-35% N2S; and the balance water. In some specific embodiments, the feedstock mixture comprises: 25% MOH; 1% diethyl ether; 1% M2CO3; 30% M2S; and the balance water.

[0036] S200: Carbon disulfide gas is introduced into the raw material mixture solution, and a copper precipitating coagulant is obtained after the reaction.

[0037] According to some embodiments of the present invention, the molar amount of carbon disulfide is related to the amount of M(OH) in the raw material solution. zThe molar ratio of carbon disulfide to N₂S is 2.2:3 to 2.4:3, specifically 2.2:3, 2.25:3, 2.3:3, 2.35:3, and 2.4:3. This effectively ensures the complete reaction of carbon disulfide, avoids waste of raw materials, and guarantees the reaction of M(OH). z Sufficient M2S provides a good alkaline environment for the reaction environment and the resulting copper precipitator, thus preventing the generation of hydrogen sulfide.

[0038] After carbon disulfide gas is introduced into the raw material mixture solution, the carbon disulfide reacts with M(OH)2. z It reacts with N₂S (taking sodium as an example where M and N are metallic sodium, the reactions include: 2NaOH + CS₂ = Na₂COS₂ + H₂O; Na₂S + CS₂ = Na₂CS₃), and the solution after the reaction is composed of MCxO 3-x M2CO3, diethyl ether, M(OH) z A mixed aqueous solution composed of the following substances is the copper precipitation flocculant. Among them, M(OH) z N₂S is used as a reactant, and M(OH)₂ is also reacted. z It also provides an alkaline environment for the synthesis of copper plating coagulants, which effectively prevents hydrogen sulfide from escaping during and after the synthesis process; diethyl ether is used to accelerate the generation of M during the preparation of the copper plating coagulant. y CO x S 3-x The catalyst that accelerates the reaction of carbon disulfide with M(OH) z The reaction of N2S; M2CO3 does not participate in the reaction process, but in the subsequent process of separating copper-containing particles by pressure filtration, M2CO3 can make the flow rate of the filtrate in the pressure filtration faster, the dehydration effect of copper-containing particles (or copper mud) is better, and the water content in the obtained copper-containing particles (or copper mud) is less.

[0039] Furthermore, N2S can be added in excess to the above raw materials, so the resulting copper precipitating coagulant will also contain a certain amount of N2S. During the treatment of copper-containing wastewater, the S in the copper precipitating coagulant... 2- It can further combine with copper ions in the supernatant, thereby reducing the copper ion content in the supernatant and increasing the copper content in the copper mud. In addition, the interaction between copper and sulfur is much greater than the interaction between copper and organic matter. Therefore, the presence of N2S can give this coagulant a certain ability to break the complexation between copper and organic matter, i.e., complex breaking ability, thereby enhancing its ability to coagulate copper.

[0040] In some embodiments, carbon disulfide and M(OH) z The reaction of N2S can be carried out at room temperature. Therefore, the above method for preparing copper plating coagulant has mild process conditions, which is conducive to further reducing process costs.

[0041] According to some embodiments of the present invention, the copper plating coagulant prepared by the above method has a significant effect: due to the M in the copper plating coagulant y CO x S 3-x The sulfur in the copper-containing wastewater exhibits a strong interaction with the copper, and the copper-laden coagulant is readily soluble in water. This interaction between the sulfur-containing groups and the copper precipitate creates a bridging effect, binding one or more particles together around the coagulant. This rapid aggregation of particles leads to a significant increase in particle size, effectively coagulating the copper precipitate in the wastewater into larger copper-containing particles. These particles can then be directly separated by pressure filtration without the need for PAM (polyacrylamide), thus eliminating the use of PAM flocculant in copper recovery. This simplifies the treatment process for copper-laden wastewater, reduces treatment costs, and improves copper recovery efficiency. Furthermore, the separated copper-laden product has high economic value. The coagulant does not contain iron, aluminum, or other metal cations, and the main agglomerative component is a sulfur-containing anion group. Therefore, no metal impurities are introduced into the product, further enhancing its economic value. Additionally, the sulfur in the product can be converted into sulfuric acid during smelting, further increasing its economic value. Furthermore, the above-mentioned method for preparing copper plating coagulant uses inexpensive raw materials, has a simple synthesis process, mild synthesis conditions, and low synthesis cost. The resulting copper plating coagulant plays a role in the copper recycling process, and the product utilization rate after synthesis is high, making the copper plating coagulant of the present invention highly cost-effective.

[0042] In another aspect, the present invention provides an application of the aforementioned copper-coagulant in the treatment of copper-containing wastewater. This effectively improves the efficiency of copper recovery from copper-containing wastewater and reduces recovery costs.

[0043] According to embodiments of the present invention, the copper plating coagulant of the present invention can be applied to the treatment of copper-containing wastewater in any industry. In some embodiments, the copper plating coagulant of the present invention can be applied to the treatment of copper-containing wastewater in the PCB industry, copper plating industry, electrolytic copper industry, and lithium battery copper foil industry. Therefore, the application field of the copper plating coagulant of the present invention is not particularly limited and has a relatively wide range of applications.

[0044] In another aspect, the present invention provides a method for treating copper-containing wastewater using the aforementioned copper-plating coagulant. According to an embodiment of the present invention, the method for treating copper-containing wastewater using the copper-plating coagulant includes:

[0045] T100: Adjusts the pH of copper-containing waste liquid to alkaline.

[0046] In some embodiments, the pH of copper-containing waste liquid can be adjusted to 8-9 using alkalis such as sodium hydroxide or potassium hydroxide, which is conducive to the formation of copper-containing precipitates such as basic copper sulfate, copper hydroxide, or a mixture of the two.

[0047] T200: Add copper-precipitating coagulant to copper-containing waste liquid, stir, and obtain a mixture of copper-containing particles.

[0048] In this process, such as Figure 1 As shown ( Figure 1 Taking M2CO1S2 as an example, due to the M in the copper plating coagulant y CO x S 3-x The interaction between sulfur-containing groups and copper is extremely strong. These sulfur-containing groups act like bridges, connecting one or more copper-containing particles, leading to a rapid increase in particle size. With the addition of this coagulant, the D50 of copper hydroxide or basic copper sulfate particles can rapidly increase from a few micrometers to tens of micrometers. In some embodiments of the present invention, the D50 of the copper-containing particles can reach 40–100 micrometers, for example, 40–50 micrometers, 50–60 micrometers, 60–70 micrometers, 70–80 micrometers, 80–90 micrometers, and 90–100 micrometers, etc.

[0049] The dosage and concentration of the copper-containing coagulant can be flexibly adjusted according to the actual situation, such as the copper content in the copper-containing waste liquid and the volume of the copper-containing waste liquid to be treated, and no restrictions are imposed here.

[0050] T300: Filter the mixture containing copper particles to obtain copper particles and treated waste liquid.

[0051] In some embodiments of the present invention, the rapid increase in the particle size of copper-containing particles allows the precipitate to be directly filtered by pressure, thereby avoiding the problem of copper sludge impurities introduced by adding polyferric chloride / polyaluminum chloride and PAM, reducing treatment costs and reducing the number of treatment steps for copper-containing waste sludge.

[0052] Furthermore, because this copper slurry coagulant also contains some sodium carbonate, the filtrate flows faster during pressure filtration, resulting in better dehydration of the copper sludge and a lower water content, thus reducing transportation costs. Additionally, if the copper slurry coagulant further contains sulfur... 2- S 2-It can further combine with copper ions in the supernatant, leading to a further decrease in the copper ion content in the supernatant and an increase in the copper content in the copper sludge. Furthermore, when N2S is further included in this copper-precipitating coagulant, the interaction between copper and sulfur is much stronger than the interaction between copper and organic matter. Therefore, the presence of N2S enables this coagulant to also possess a certain ability to break the complexation between copper and organic matter, i.e., complex-breaking ability, thereby enhancing its ability to coagulate copper. In addition, the above method for treating copper-containing wastewater is simple, operates under mild conditions, has low implementation costs, and achieves high copper recovery efficiency.

[0053] According to some embodiments of the present invention, in step T300, the filtration uses a filter cloth of 200-800 mesh (e.g., 200 mesh, 250 mesh, 300 mesh, 350 mesh, 400 mesh, 450 mesh, 500 mesh, 550 mesh, 600 mesh, 650 mesh, 700 mesh, 750 mesh, 800 mesh, etc.). The copper-containing particles obtained in this invention have a relatively large particle size, so a lower mesh filter cloth can be used for filtration and collection, thus greatly reducing the difficulty of filtration and shortening the filtration time. In some specific embodiments, a 300-600 mesh filter cloth is sufficient for filtering and recovering the copper-containing particles. If the copper-precipitating coagulant of the present invention is not used, i.e., if the pH is adjusted to 10-11 in step T100, and the copper-containing waste liquid generates copper-containing precipitates such as basic copper sulfate, copper hydroxide, or a mixture of both, and then directly filtered, then a filter cloth of 2000 mesh (e.g., 2500 mesh) or higher is needed to filter the copper-containing precipitate for several hours (e.g., more than 4 hours). Moreover, a comparison of the two treatment methods revealed that the copper content in the wet copper sludge obtained without adding the copper-laden coagulant was around 29%, while the copper content in the wet copper sludge increased to around 35% after adding the copper-laden coagulant, and the water content decreased from around 47.29% without adding the copper-laden coagulant to around 44.99%, which greatly improved the economic value of the copper-containing sludge.

[0054] Example

[0055] Example 1

[0056] First, 4 mol of CS2 is passed into a solution containing 2 mol of NaOH, 0.5% (w / w) diethyl ether, 0.5 mol / L sodium carbonate, and 4 mol of Na2S. After reacting at room temperature for 5 minutes, a copper precipitating coagulant is obtained. The resulting solution is copper precipitating coagulant A, composed mainly of Na2COS2, supplemented by Na2CS3, 0.5% diethyl ether, and 0.5% sodium carbonate. This copper precipitating coagulant A is then prepared at a concentration of 30%, i.e., copper precipitating coagulant mixed solution B. Copper precipitating coagulant mixed solution B includes 30% Na2CO3. x S 3-x 4% NaOH, 0.5% diethyl ether and 0.5% sodium carbonate.

[0057] Second, copper-containing wastewater was tested. The copper content in the wastewater was 8960 mg / L, the COD was 1095 mg / L, the pH was 0.13, and the main anion was SO42-. 2- Adding a certain amount of NaOH to adjust the pH of the copper-containing waste liquid to 9, the copper-containing precipitate formed in the waste liquid at this time is a mixture of basic copper sulfate and copper hydroxide, and its particle size distribution is as follows. Figure 2 As shown in (a), the D50 of the copper precipitate is 6.5 μm, the copper content of the wet mud containing the copper precipitate is 29.51%, and the copper content of the supernatant is 65.43 ppm (the original solution contains some complexed copper, and adding alkali cannot precipitate the copper in the complexed copper).

[0058] Third, adding 270 mg / L of the above-mentioned copper-containing coagulant mixture B (i.e., using 270 mg of copper-containing coagulant mixture B per liter of copper-containing wastewater) caused the pH of the copper-containing wastewater to rise from 9 to 10.5. After stirring for 4 minutes, the particle size of the copper-containing particles increased significantly. At this point, the D50 of the copper-containing particles rapidly increased from 6.5 μm to 69 μm, an increase of 9.61 times (its particle size distribution is as follows). Figure 2 As shown in (b) below, under these conditions, copper-containing particles can be filtered and recovered using a 300-mesh filter cloth. After filtration through the 300-mesh filter cloth for 2 hours, the copper content in the wet copper sludge was 35.12%, an increase of 19.01% compared to before the addition of the copper-precipitating flocculant, significantly increasing the value of the copper sludge. Furthermore, the copper content in the supernatant after filtration was 7.97 ppm, a decrease of 87.82% compared to before the addition of the copper-precipitating flocculant, reducing the difficulty of subsequent supernatant treatment.

[0059] Example 2

[0060] First, 4 mol of CS2 is passed into a solution containing 2 mol of KaOH, 1.5% diethyl ether, 2 mol / L potassium carbonate, and 5 mol of Ka2S. After reacting at room temperature for 4 minutes, a copper precipitating coagulant is obtained. The resulting solution is copper precipitating coagulant A, composed mainly of Ka2CS3, supplemented by Ka2COS2, 1.5% diethyl ether, and 1.5% potassium carbonate. This copper precipitating coagulant A is then prepared to a 60% concentration for later use, namely, copper precipitating coagulant mixed solution B. Copper precipitating coagulant mixed solution B includes 60% Ka2CO3. x S 3-x It contains 6% KaOH, 1.5% diethyl ether, and 1.5% potassium carbonate.

[0061] Second, tests were conducted on copper-containing wastewater from the PCB factory. The copper content in the wastewater was 23142 mg / L, the COD was 456 mg / L, the pH was 0.05, and the main anion was Cl. -Adding a certain amount of alkali KaOH to adjust the pH of the copper-containing waste liquid to 9, the copper-containing precipitate formed in the waste liquid at this time is copper oxide (due to the large amount of alkali added and the high solution temperature, copper hydroxide is converted into copper oxide), and its particle size distribution is as follows. Figure 3 As shown in (a), the D50 of the copper precipitate is 5 μm, the copper content of the wet mud containing the copper precipitate is 31.25%, and the copper content of the supernatant is 31.31 ppm.

[0062] Third, after adding 540 mg / L of the above-mentioned copper-containing coagulant mixture B (i.e., using 540 mg of copper-containing coagulant mixture B per liter of copper-containing wastewater), the pH of the copper-containing wastewater increased from 9 to 10.7. After stirring for 3 minutes, the particle size of the copper-containing particles increased significantly. At this time, the D50 of the copper-containing particles rapidly increased from 5 μm to 75 μm, an increase of 15 times (its particle size distribution is as follows). Figure 3 As shown in (b) below, under these conditions, copper-containing particles can be filtered and recovered using a 250-mesh filter cloth. After filtration through the 250-mesh filter cloth for 1.5 hours, the copper content in the wet copper sludge was 35.79%, an increase of 14.53% compared to before the addition of the copper-precipitating flocculant, significantly increasing the value of the copper sludge. Furthermore, the copper content in the supernatant after filtration was 5.13 ppm, a decrease of 83.61% compared to before the addition of the copper-precipitating flocculant, reducing the difficulty of subsequent supernatant treatment.

[0063] Example 3

[0064] First, 4 mol of CS2 is passed into a solution containing 2 mol of NaOH, 1% diethyl ether, 1 mol / L sodium carbonate, and 5 mol of Na2S. After reacting at room temperature for 4 minutes, a copper precipitating coagulant is obtained. The resulting solution is copper precipitating coagulant A, composed mainly of Na2CS3, supplemented by Na2COS2, 1% diethyl ether, and 1% sodium carbonate. This copper precipitating coagulant A is then prepared to a 45% concentration for later use, namely, copper precipitating coagulant mixed solution B. Copper precipitating coagulant mixed solution B includes 45% Na2CO3. x S 3-x 5% NaOH, 1% diethyl ether and 1% sodium carbonate.

[0065] Second, copper-containing wastewater from the copper foil electroplating plant was tested. The copper content in the wastewater was 1156 mg / L, COD was 695 mg / L, pH was 0.05, and the main anion was SO42-. 2- Adding a certain amount of NaOH to adjust the pH of the copper-containing waste liquid to 9, the copper-containing precipitate generated in the waste liquid at this time is a mixture of basic copper sulfate and copper hydroxide. The D50 of the copper-containing precipitate is 6.92 μm, the copper content of the wet mud precipitate is 30.16%, and the copper content of the supernatant is 54.31 ppm (the original solution contains some complexed copper, and adding alkali cannot precipitate the copper in the complexed copper).

[0066] Third, adding 135 mg / L of the aforementioned copper-laden flocculant mixture B (i.e., using 135 mg of copper-laden flocculant mixture B per liter of copper-containing wastewater) raised the pH of the copper-laden wastewater from 9 to 10. After stirring for 4 minutes, the particle size of the copper-containing particles increased significantly. At this point, the D50 of the copper-laden particles rapidly increased from 6.92 μm to 65 μm, an increase of 8.39 times. Under these conditions, copper-laden particles could be filtered and recovered using a 300-mesh filter cloth. After 2 hours of filtration through a 300-mesh filter cloth, the copper content in the wet copper sludge was 33.74%, an increase of 11.87% compared to before the addition of the copper-laden flocculant, greatly increasing the value of the copper sludge. The copper content in the supernatant after filtration was 10.96 ppm, a decrease of 79.82% compared to before the addition of the copper-laden flocculant, reducing the difficulty of subsequent supernatant treatment.

[0067] Example 4

[0068] First, 4 mol of CS2 is passed into a solution containing 2 mol of NaOH and 4 mol of Na2S. The reaction is allowed to proceed for 30 minutes at room temperature to obtain the copper precipitating coagulant. At this point, the resulting solution is primarily composed of Na2COS2 and Na2CS3, forming copper precipitating coagulant A. This coagulant A is then prepared at a concentration of 30%, known as copper precipitating coagulant mixed solution B. Coagulant mixed solution B contains 30% Na2CO3. x S 3-x And 4% NaOH.

[0069] Second, the same copper-containing wastewater as in Example 1 was used for testing. The copper content in the wastewater was 8960 mg / L, the COD was 1095 mg / L, the pH was 0.13, and the main anion was SO42-. 2- Adding a certain amount of NaOH to adjust the pH of the copper-containing waste liquid to 9, the copper-containing precipitate generated in the waste liquid at this time is a mixture of basic copper sulfate and copper hydroxide. The D50 of the copper-containing precipitate is 5.9 μm, the copper content of the wet mud containing the copper-containing precipitate is 28.31%, and the copper content of the supernatant is 67.21 ppm (the original solution contains some complexed copper, and adding alkali cannot precipitate the copper in the complexed copper).

[0070] Third, adding 270 mg / L of the aforementioned copper-containing coagulant mixture B (i.e., using 270 mg of copper-containing coagulant mixture B per liter of copper-containing wastewater) caused the pH of the copper-containing wastewater to rise from 9 to 10.1. After stirring for 4 minutes, the particle size of the copper-containing particles increased significantly, with the D50 of the copper-containing particles rapidly increasing from 5.9 μm to 65 μm, an increase of 10.02 times. The copper content in the supernatant decreased to 9.53 ppm. Under these conditions, copper-containing particles could be filtered and recovered using a 300-mesh filter cloth. After filtration through a 300-mesh filter cloth for 2 hours, the copper content in the resulting wet copper sludge was 32.01%.

[0071] Comparative Example 1

[0072] The copper-containing wastewater from Example 1 was tested. The copper content in the wastewater was 8931 mg / L, the COD was 995 mg / L, the pH was 0.13, and the main anion was SO42-. 2- A certain amount of alkali was added to adjust the pH of the solution to 10.5. Under these conditions, the D50 of the copper precipitate was 6.46 μm. The solution was then filtered for 4.5 hours using a filter press with a 2500-mesh filter cloth. The copper content in the resulting copper mud was 29.32%, and the copper content in the supernatant was 65.51 ppm.

[0073] Comparative Example 2

[0074] The copper-containing wastewater from Example 2 was tested. The copper content in the wastewater was 23187 mg / L, the COD was 431 mg / L, the pH was 0.08, and the main anion was Cl. - A certain amount of alkali was added to adjust the pH of the solution to 10.7. Under these conditions, the D50 of the copper oxide precipitate was 5.2 μm. The solution was then filtered for 5.5 hours using a filter press with a 3000-mesh filter cloth. The copper content in the resulting copper mud was 30.14%, and the copper content in the supernatant was 29.56 ppm.

[0075] Comparative Example 3

[0076] The copper-containing wastewater from Example 3 was tested. The copper content in the wastewater was 1156 mg / L, the COD was 652 mg / L, the pH was 0.05, and the main anion was SO42-. 2- A certain amount of alkali was added to adjust the pH of the solution to 10. Under these conditions, the copper precipitate produced was a mixture of basic copper sulfate and copper hydroxide, with a D50 of 6.13 μm. The solution was filtered for 4.5 hours using a filter press with a 2500-mesh filter cloth. The copper content in the resulting copper mud was 30.03%, and the copper content in the supernatant was 53.43 ppm.

[0077] The test data for the above embodiments and comparative examples can be found in Table 1.

[0078] Table 1

[0079]

[0080] As can be seen from the data of the embodiments and comparative examples in Table 1 above, the copper precipitating coagulant of the present invention has significant effects in reducing the copper content of the supernatant, increasing the copper content in copper sludge, and increasing the particle size of copper-containing particles.

[0081] As can be seen from Example 4 compared with Example 1, the addition of an appropriate amount of diethyl ether can significantly accelerate the preparation process of the copper precipitating flocculant (the reaction time in Example 1 was 5 minutes, while the reaction time in Example 4 was 30 minutes). At the same time, the addition of sodium carbonate can increase the copper mud content after filtration. The copper precipitating flocculant with added sodium carbonate in Example 1 increased by 3.11% compared with that in Example 4.

[0082] The parameter testing method is as follows:

[0083] Copper content: In the above embodiments, the copper content of copper sludge and supernatant was tested by ICP (equipment model: PerkinElmer AVi200). A certain amount of supernatant was taken, and the solution was diluted by a certain factor so that the copper content in the solution was within the range of ICP standard solution, and then the sample was injected for measurement. A certain amount of copper-containing sludge was taken and dissolved with aqua regia. After dissolution, the supernatant was obtained by filtration. The supernatant was diluted by a certain factor so that the copper content in the supernatant was within the range of ICP standard solution, and then the sample was injected for measurement.

[0084] COD testing: COD testing adopts the potassium dichromate method (equipment model: Lianhua Technology LH-T600), and the measurement method is GB11914-89.

[0085] Particle size testing: Particle size was measured using laser particle size analysis (equipment model: Mastersize 4000). The method involved dispersing the copper-containing precipitate in water, maintaining its suspension state using ultrasound and stirring, and then injecting the sample to measure the particle size of the copper-containing precipitate.

[0086] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "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 present 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. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0087] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. The use of a copper-precipitating coagulant in the treatment of copper-containing wastewater, characterized in that, Based on the total mass of the copper plating coagulant, the copper plating coagulant comprises, by mass percentage: 30%~60% M y CO x S 3-x ; 2%~8% M(OH) z ; 0.5%~1.5% diethyl ether; 0.5%~1.5% M2CO3; and 29%~67% water Where M is at least one of Na, K, and Mg, 0 ≤ x ≤ 1, y is 1 or 2, and z is 2 or 1. The preparation method of the copper plating coagulant includes: A raw material mixture solution is provided, the raw material mixture solution comprising M(OH) z N2S, diethyl ether, M2CO3, and water, wherein N is at least one of Na and K; Carbon disulfide gas is introduced into the raw material mixture solution, and the copper precipitating coagulant is obtained after the reaction.

2. The use according to claim 1, characterized in that, The copper plating coagulant includes: 40% to 50% of M y CO x S 3-x ; 4%~6% M(OH) z ; 0.8%~1.2% ether; 0.8%~1.2% M2CO3; and 41.6%~54.4% water.

3. The use according to any one of claims 1 to 2, characterized in that, Based on the total mass of the copper plating coagulant, the copper plating coagulant further includes, by mass percentage: 0-5% N2S, where N is at least one of Na and K.

4. The use according to claim 1, characterized in that, Based on the total mass of the raw material mixture solution, the raw material mixture solution comprises, by mass percentage: 20%-30% M(OH) z ; 0.5%-1.5% diethyl ether; 0.5%-1.5% M2CO3; 25%-35% N2S; and the remainder water.

5. The use according to claim 4, characterized in that, The molar amount of carbon disulfide is related to the amount of M(OH) in the raw material solution. z The ratio of the molar amounts of N2S to the total molar amounts of N2S is 2.2:3 to 2.4:

3.

6. A method for treating copper-containing wastewater using a copper-precipitating coagulant, characterized in that, include: The pH of the copper-containing waste liquid was adjusted to alkaline. Add a copper-precipitating coagulant to the copper-containing waste liquid and stir to obtain a mixture of copper-containing particles; The copper-containing particle mixture was filtered to obtain copper-containing particles and treated waste liquid. Based on the total mass of the copper plating coagulant, the copper plating coagulant comprises, by mass percentage: 30% to 60% of M y CO x S 3-x ; 2%~8% M(OH) z ; 0.5%~1.5% diethyl ether; 0.5%~1.5% M2CO3; and 29%~67% water Where M is at least one of Na, K, and Mg, 0 ≤ x ≤ 1, y is 1 or 2, and z is 2 or 1. The preparation method of the copper plating coagulant includes: A raw material mixture solution is provided, the raw material mixture solution comprising M(OH) z N2S, diethyl ether, M2CO3, and water, wherein N is at least one of Na and K; Carbon disulfide gas is introduced into the raw material mixture solution, and the copper precipitating coagulant is obtained after the reaction.

7. The method according to claim 6, characterized in that, The copper-containing particles have a particle size of 40-100 micrometers.

8. The method according to claim 6 or 7, characterized in that, The filtration process uses filter cloth with a mesh size of 200 to 800.

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