A treatment and resource recovery method for electroplating cyanide copper wastewater

Abstract

The present application discloses a method for treating and resourcefully recycling electroplating cyanide copper wastewater, belonging to the technical field of electroplating wastewater treatment. In this application, the cyanide copper wastewater is adjusted with strong base, and a ferrous sulfate solution is added to the cyanide copper wastewater after strong base adjustment for a combination reaction; the cyanide copper wastewater after the combination reaction is adjusted with acid and subjected to a Prussian blue reaction; a coagulant aid is added to the solution after the Prussian blue reaction, and solid-liquid filtration separation is carried out on it to obtain iron cyanide sludge and preliminarily precipitated cyanide-removing wastewater; the preliminarily precipitated cyanide-removing wastewater is adjusted with weak base, hydrogen peroxide is added to the preliminarily precipitated cyanide-removing wastewater after weak base adjustment, and the copper in the preliminarily precipitated cyanide-removing wastewater after weak base adjustment is used as a catalyst for an oxidation reaction to remove the remaining cyanide-containing pollutants; after the oxidation reaction is completed, lime is added for flocculation precipitation to obtain copper sludge, thus realizing a one-step process flow, converting copper cyanide compounds into resources that can be recycled, and improving the resource utilization rate.

Description

Technical Field

[0001] The present application relates to the technical field of electroplating wastewater treatment, and particularly relates to a method for treating and resourcefully recycling electroplating cyanide copper wastewater. Background Art

[0002] The commonly used existing method for treating cyanide copper wastewater is the alkaline chlorination method. Its principle is to utilize the oxidizing property of chlorine-containing oxides (such as sodium hypochlorite, chlorine dioxide, liquid chlorine, bleaching powder, etc.). Under alkaline conditions, the cyanide-containing compounds are first oxidized and hydrolyzed into cyanates with lower toxicity, and then further oxidized into non-toxic bicarbonates and nitrogen, so as to achieve the removal of cyanide-containing compounds and heavy metals.

[0003] However, in the process of treating cyanide copper wastewater by the alkaline chlorination method, the chloride ions can destroy the pollutant cyanide radical and decompose the cyanide compounds into bicarbonates and nitrogen. However, this method does not recycle the cyanide radical, reducing the utilization rate of resource recovery of cyanide copper wastewater. Summary of the Invention

[0004] The main purpose of the present application is to provide a method for treating and resourcefully recycling electroplating cyanide copper wastewater, aiming to solve the technical problem that the cyanide radical is not recycled, reducing the utilization rate of resource recovery of cyanide copper.

[0005] To achieve the above purpose, the present application provides a method for treating and resourcefully recycling electroplating cyanide copper wastewater. The method for treating and resourcefully recycling electroplating cyanide copper wastewater includes the following steps:

[0006] Strong base adjustment is carried out on the cyanide copper wastewater, and a ferrous sulfate solution is put into the cyanide copper wastewater after strong base adjustment for a combination reaction, and the pH value of the solution during the entire combination reaction process is controlled to be 10 - 11, so that the ferrous sulfate solution and the cyanide in the cyanide copper wastewater carry out a combination reaction to generate ferrocyanide ions. Among them, the reaction time of the combination reaction is 1 - 2h;

[0007] Acid adjustment is carried out on the cyanide copper wastewater after the combination reaction, and a Prussian blue reaction is carried out when its pH value is 4.5 - 5.5, so that the ferrous ions in the cyanide copper wastewater after the combination reaction first react with the ferrocyanide ions, and the copper in the cyanide copper wastewater after the combination reaction is freed in the solution;

[0008] A coagulant aid is put into the solution after the Prussian blue reaction, and solid-liquid filtration separation is carried out on it to obtain iron cyanide mud and preliminarily precipitated cyanide-removed wastewater. Among them, the iron cyanide mud is used as a raw material for yellow blood salt for resource treatment;

[0009] Adjust the pH of the preliminary cyanide-removing wastewater to weak alkaline, add hydrogen peroxide to the preliminary cyanide-removing wastewater after weak alkaline adjustment, use the copper in the preliminary cyanide-removing wastewater after weak alkaline adjustment as a catalyst for the oxidation reaction, and control the pH value of the solution during the whole oxidation reaction process to be 6.5 - 7.5 to remove the remaining cyanide-containing pollutants. Among them, the reaction time of the oxidation reaction is 1 - 2h;

[0010] After the oxidation reaction ends, add lime for flocculation precipitation to obtain copper sludge, and the copper sludge is subsequently subjected to resource treatment.

[0011] In one embodiment, the cyanide-copper wastewater contains at least free cyanide and copper cyanide complexes;

[0012] Among them, according to the stability constant of copper cyanide complexes, the solubility product of ferrocyanate, and the pH value during the corresponding reaction, the ferrous ions first react with the cyanide radicals in the copper cyanide complexes, and then react with the copper ions in the copper cyanide complexes, so that the cyanide radicals are preferentially transferred and separated, and a precipitate of iron cyanide sludge is formed.

[0013] In one embodiment, the reagents used for the strong alkaline adjustment and the weak alkaline adjustment are NaOH with a mass concentration of 10% - 30%.

[0014] In one embodiment, the mass concentration of the ferrous sulfate solution is 10% - 25%.

[0015] In one embodiment, the reagents used for the acid adjustment are hydrochloric acid or sulfuric acid. The mass concentration of the hydrochloric acid is 10% - 30%, and the mass concentration of the sulfuric acid is 10% - 40%.

[0016] In one embodiment, the coagulant aids are polyaluminum chloride and / or polyacrylamide. Among them, the mass concentration of polyaluminum chloride is 5 - 10%, and the mass concentration of polyacrylamide is 0.5 - 1.0%.

[0017] In one embodiment, the solid-liquid filtration and separation method is plate and frame pressure filtration.

[0018] In one embodiment, the mass concentration of hydrogen peroxide is 7%.

[0019] In one embodiment, the component of the lime is Ca(OH)2 with a mass concentration of 10% - 20%.

[0020] One or more technical solutions proposed in this application have at least the following technical effects: By adjusting the cyanide copper wastewater with strong alkali, adding ferrous sulfate solution to the cyanide copper wastewater after strong alkali adjustment for a combination reaction; adjusting the pH of the cyanide copper wastewater after the combination reaction with acid and conducting a Prussian blue reaction; adding a coagulant aid to the solution after the Prussian blue reaction and performing solid-liquid filtration separation to obtain iron cyanide sludge and preliminarily precipitated cyanide-removing wastewater; adjusting the pH of the preliminarily precipitated cyanide-removing wastewater with weak alkali, adding hydrogen peroxide to the preliminarily precipitated cyanide-removing wastewater after weak alkali adjustment, and using the copper in the preliminarily precipitated cyanide-removing wastewater after weak alkali adjustment as a catalyst for an oxidation reaction to remove the remaining cyanide-containing pollutants; after the oxidation reaction, adding lime for flocculation precipitation to obtain copper sludge, thereby realizing a single process flow. First, the cyanide in the cyanide copper wastewater reacts with ferrous ions to generate ferrocyanide ions, and through the Prussian blue reaction, it is converted into iron cyanide sludge, and the copper ions in the wastewater after subsequent cyanide removal are coagulated and precipitated to obtain copper sludge, thereby realizing the conversion of copper cyanide compounds in the cyanide copper wastewater into copper resources and cyanide resources that can be recycled respectively, and then realizing the recovery efficiency of various elemental resources in the cyanide copper wastewater, thereby improving the resource utilization rate of the cyanide copper wastewater. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The drawings herein are incorporated into and constitute a part of this specification, showing embodiments consistent with this application and, together with the specification, used to explain the principles of this application.

[0022] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, for those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0023] Figure 1 It is a schematic flow chart provided for Embodiment 1 of the method for treating and resourcefully recycling electroplated cyanide copper wastewater in this application;

[0024] Figure 2 It is a schematic diagram of the overall process flow of the method for treating and resourcefully recycling electroplated cyanide copper wastewater in this application.

[0025] The realization of the purpose of this application, functional features and advantages will be further described with reference to the embodiments and the drawings. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0026] It should be understood that the specific embodiments described herein are only used to explain the technical solutions of this application and are not used to limit this application.

[0027] It should be noted first that in the current existing technologies, the main process of the treatment solution for sewage containing cyanide copper compounds generally includes destroying the cyanide radicals, converting the nitrogen elements contained therein into nitrogen gas, and extracting the heavy metals in the sewage after removing the cyanide radicals and recycling the resources. In this process, the recycling of cyanide radicals is not considered.

[0028] In addition, most of the above treatment solutions involve alkaline oxidation methods. Under alkaline conditions, the cyanide-containing compounds are first oxidized and hydrolyzed into cyanates with lower toxicity, and then further oxidized into non-toxic bicarbonates and nitrogen gas, so as to achieve the removal of cyanide-containing compounds and heavy metals. However, in addition to the problem of not considering the recycling of cyanide radicals, there are also the following multiple problems:

[0029] 1. The reagent cost of the alkaline chlorination method is high; 2. The alkaline chlorination method for treating cyanide copper wastewater introduces a large amount of chloride ions, and the chloride ions cannot be effectively removed in the subsequent process, which has a greater impact on the biochemical system, recycling and evaporation systems, etc.; 3. The alkaline chlorination method can remove most of the complex cyanides, but cannot decompose iron cyanide complexes.

[0030] Based on the four problems described above, the embodiments of the present application provide a method for treating and resource recycling of electroplating cyanide copper wastewater. Refer to Figure 1 , Figure 1 which is a schematic flow chart of the first embodiment of the method for treating and resource recycling of electroplating cyanide copper wastewater of the present application.

[0031] In the first embodiment, the method for treating and resource recycling of electroplating cyanide copper wastewater includes the following steps:

[0032] S10, adjust the cyanide copper wastewater with strong base, put the ferrous sulfate solution into the cyanide copper wastewater after strong base adjustment for a combination reaction, and control the pH value of the solution during the entire combination reaction process to be 10-11, so that the ferrous sulfate solution and the cyanide in the cyanide copper wastewater undergo a combination reaction to generate ferrocyanide ions, wherein the reaction time of the combination reaction is 1-2h;

[0033] It should be noted that the cyanide copper wastewater involved in this embodiment specifically refers to cyanide / cyanide copper wastewater, which mainly contains free cyanide (CN - ), copper cyanide complex (the main existing form is Cu(CN)3 2- ), and zinc cyanide complex (Zn(CN)4 2- ), etc.

[0034] In this embodiment, when adjusting the cyanide copper wastewater with strong base, the reagent used can be NaOH with a mass concentration of 10% - 30%. During the strong base adjustment process, an independent pH adjustment tank can be planned, and the cyanide copper wastewater and NaOH are added to this pH adjustment tank together, and corresponding stirring and mixing actions are carried out.

[0035] In this embodiment, after the cyanide copper wastewater is completed with strong base adjustment, the overall idea of the treatment process for the cyanide copper wastewater is to first remove the cyanide radicals in the cyanide copper wastewater, and then precipitate the heavy metals in the wastewater after removing the cyanide radicals once. During the process of removing the cyanide radicals, in order to ensure the recycling of the cyanide radicals, a combined reaction method is adopted, so that the cyanide radicals combine with iron elements to obtain iron cyanide sludge.

[0036] Specifically, the ferrous sulfate solution is put into the cyanide copper wastewater after strong base adjustment to make the two undergo a combined reaction. At the same time, during the entire reaction process, the pH value of the solution in the entire pH adjustment tank is controlled to be 10 - 11, and the reaction time is maintained for 1 - 2 hours, so that the ferrous sulfate solution and the cyanide in the cyanide copper wastewater undergo a combined reaction to generate ferrocyanide ions.

[0037] In one embodiment, the mass concentration of the ferrous sulfate solution is 10% - 25%.

[0038] It should be noted that during the combined reaction process, an automated device is used to monitor the pH value of the solution in the reaction in real time, and when its current pH value is lower or higher than 10 - 11, a reagent is added to control the pH value to maintain a stable state.

[0039] In one embodiment, the cyanide copper wastewater contains at least free cyanide and copper cyanide complexes;

[0040] Among them, according to the stability constant of the copper cyanide complex, the solubility product of ferrous cyanate, and the pH value during the corresponding reaction, the ferrous ions first react with the cyanide radicals in the copper cyanide complex, and then react with the copper ions in the copper cyanide complex, so that the cyanide radicals are preferentially transferred and separated, and a precipitate of iron cyanide sludge is formed.

[0041] Specifically, the combined reaction occurring under alkaline conditions is mainly based on the fact that simple cyanides formed by copper, zinc, etc. and cyanide radicals are soluble in alkali, and in an alkaline solution, the cyanide radicals are dissociated, and the dissociated cyanide radicals can react with ferrous ions to produce ferrocyanide ions. The specific reaction equation is as follows:

[0042] 2Cu(CN)3 2- + Fe 2+ + 2OH - → 2CuOH↓ + [Fe(CN)6] 4-

[0043] 3Zn(CN)4 2- + 2Fe 2+ + 6OH - → 3Zn(OH)2↓ + 2[Fe(CN)6] 4-

[0044] Note: Among them, the stability constants of some metal cyanide complexes are as follows:

[0045] Zn(CN)4 2- (lgβ n = 21.57);

[0046] Cu(CN)3 2- (lgβ n = 26.8);

[0047] Fe(CN)6 4- (lgβ n = 36.9).

[0048] In addition, if non-oxidizing acid is added to heavy metal cyanide complexes under non-alkaline conditions, cyanide precipitates will be formed:

[0049] Cu(CN)3 2- + 2H + → 2HCN + CuCN↓

[0050] Zn(CN)4 2- + 2H + → 2HCN + Zn(CN)2↓

[0051] In summary, in this embodiment, it is necessary to control the reaction conditions of the above combination reaction depending on maintaining an alkaline solution environment in dynamic equilibrium.

[0052] S20. Acidify the cyanide copper wastewater after the combination reaction, and carry out the Prussian blue reaction when its pH value is 4.5 - 5.5, so that the ferrous ions in the cyanide copper wastewater after the combination reaction react with the ferrocyanide ions first, and the copper in the cyanide copper wastewater after the combination reaction is freed in the solution;

[0053] It should be noted that the Prussian blue reaction specifically includes adding corresponding hydrochloric acid or FeSO4 to the cyanide copper wastewater after the combination reaction, so that an acid precipitation reaction occurs between the two, so that the ferrous ions react with the ferrocyanide ions in the cyanide copper wastewater, and the copper ions in the cyanide copper wastewater are freed in the solution.

[0054] Among them, the specific equation involved in the Prussian blue reaction (the process of forming iron cyanide precipitate) is as follows:

[0055] 6CN - + 3FeSO4 → 3SO4 2- + Fe2[Fe(CN)6]↓

[0056] Fe(CN)6 4- + 2FeSO4 → 2SO4 2- + Fe2[Fe(CN)6]↓

[0057] Among them, Fe2[Fe(CN)6] is easily oxidized by oxygen and air into Fe4[Fe(CN)6]3:

[0058] 6Fe2[Fe(CN)6] + 3O2 + 6H2O → 4Fe(OH)3↓ + 2Fe4[Fe(CN)6]3↓ (Prussian blue)

[0059] In one embodiment, the agent used for acid addition adjustment is hydrochloric acid or sulfuric acid. The mass concentration of the hydrochloric acid is 10% - 30%, and the mass concentration of the sulfuric acid is 10% - 40%.

[0060] S30. Add a coagulant aid agent to the solution after the Prussian blue reaction, and perform solid-liquid filtration separation on it to obtain iron cyanide mud and preliminary precipitation cyanide-removing wastewater. Among them, the iron cyanide mud is used as a raw material for yellow blood salt for resource treatment;

[0061] In one embodiment, the coagulant aid agent is polyaluminum chloride and / or polyacrylamide (PAC / PAM). Among them, the mass concentration of the polyaluminum chloride is 5 - 10%, and the mass concentration of the polyacrylamide is 0.5 - 1.0%.

[0062] In one embodiment, the solid-liquid filtration separation method is plate-and-frame pressure filtration.

[0063] Among them, the mixed solution after the reaction is mechanically filtered through a plate-and-frame (filter cloth filtration) to intercept the precipitate, and the supernatant is filtered out and enters the subsequent reaction. The intercepted precipitate is extruded by reverse pressure filtration to form a cake.

[0064] S40. Perform weak base adjustment on the preliminary precipitation cyanide-removing wastewater, add hydrogen peroxide to the preliminary precipitation cyanide-removing wastewater after weak base adjustment, and use the copper in the preliminary precipitation cyanide-removing wastewater after weak base adjustment as a catalyst to carry out an oxidation reaction, and control the pH value of the solution during the entire oxidation reaction process to be 6.5 - 7.5 to remove the remaining cyanide-containing pollutants. Among them, the reaction time of the oxidation reaction is 1 - 2h;

[0065] In this embodiment, when hydrogen peroxide is used and the copper in the cyanide-containing copper wastewater is used as a catalyst for the oxidation reaction, the involved chemical equation is as follows:

[0066] CN - + H2O2 + H2O → CO3 2- + NH4 + (Cu can act as a reaction catalyst)

[0067] Among them, the pH value of the solution during the entire oxidation reaction process is controlled to be 6.5 - 7.5. This control process is the same as the method for controlling the alkaline condition above, and both use automated equipment for dynamic balance control, which will not be elaborated here.

[0068] It should be noted that for the reaction between ferrocyanide and heavy metal salts, the salts formed by ferrocyanate ions and heavy metal ions are all insoluble salts, but they are all soluble in alkaline solutions. The specific reaction equations are as follows:

[0069] 2Cu 2+ + Fe(CN)6 4- → Cu2[Fe(CN)6]↓

[0070] 2Zn 2+ + Fe(CN)6 4- → Zn2Fe(CN)6↓

[0071] 2Fe 2+ + Fe(CN)6 4- → Fe2[Fe(CN)6]↓

[0072] Note: Solubility products of some ferrocyanates

[0073] Cu2[Fe(CN)6] (K sp = 1.30×10 -16 );

[0074] Zn2[Fe(CN)6] (K sp = 2.1×10 -16 );

[0075] Fe4[Fe(CN)6]3 (K sp = 3.0×10 -41 ).

[0076] In one embodiment, the reagent used for weak base adjustment is NaOH, and the mass concentration is 10% - 30%.

[0077] In one embodiment, the mass concentration of the hydrogen peroxide is 7%.

[0078] S50. After the oxidation reaction ends, lime is added for flocculation precipitation to obtain copper mud, and the copper mud is subsequently subjected to resource treatment.

[0079] In one embodiment, the lime component is Ca(OH)2 and the mass concentration is 10% - 20%.

[0080] In summary, referring to Figure 2 , combined with steps S10 - S50 and various agents involved in the above examples, the overall process flow for treating cyanide - copper wastewater can be obtained. It should be noted that the main points of this process are as follows:

[0081] 1. First, remove cyanide radicals and convert them into recoverable ferro - cyanide sludge, and avoid the scheme of destroying cyanide radicals and converting them into nitrogen gas, so as to ensure the effective recovery and reuse of cyanide radicals in the treatment process involved in this embodiment.

[0082] 2. Avoid using the alkaline oxidation method to prevent adding a large amount of difficult - to - remove chloride ions into the cyanide - copper wastewater, and realize that while removing cyanide radicals, the heavy metals in the wastewater after removing cyanide radicals can be directly extracted.

[0083] 3. Compared with the traditional treatment process of preferentially precipitating heavy metal elements and repeatedly removing cyanide radicals multiple times after precipitating heavy metals, this application only needs to execute the process flow once to produce ferro - cyanide sludge and copper sludge respectively.

[0084] In addition, according to the process flow described above, specific examples of cyanide recovery rate, copper removal / recovery rate after treating cyanide - copper wastewater are as follows:

[0085] Project 1:

[0086] Index Cyanide (mg / L) Cu (mg / L) Zn (mg / L) pH Remarks Influent (raw water) 408.5 249 5.1 10.1 Effluent from ferric cyanide reaction 18.2 Cyanide recovery rate 95.61% ＞95% Effluent from hydrogen peroxide advanced oxidation 0.095 0.137 Copper removal / recovery rate 99.94% ＞99%

[0087] Project 2:

[0088] Index Cyanide (mg / L) Cu (mg / L) Zn (mg / L) pH Remarks Influent (raw water) 819.2 516.3 33 8.9 Effluent from ferric cyanide reaction 23.1 Cyanide recovery rate 97.18% ＞95% Effluent from hydrogen peroxide advanced oxidation 0.103 0.351 Copper removal / recovery rate 99.93% ＞99%

[0089] Project 3:

[0090] Index Cyanide (mg / L) Cu (mg / L) Zn (mg / L) pH Remarks Influent (raw water) 898.9 862 113.2 10.0 Effluent from ferric cyanide reaction 31.7 Effluent from hydrogen peroxide advanced oxidation 0.165 0.322 Copper removal / recovery rate 99.96% ＞99%

[0091] In this embodiment, the cyanide copper wastewater is adjusted with strong alkali, and the ferrous sulfate solution is added to the cyanide copper wastewater after strong alkali adjustment for a combination reaction; the cyanide copper wastewater after the combination reaction is adjusted with acid and subjected to a Prussian blue reaction; a coagulant aid is added to the solution after the Prussian blue reaction, and solid-liquid filtration separation is performed on it to obtain iron cyanide sludge and preliminarily precipitated cyanide-removing wastewater; the preliminarily precipitated cyanide-removing wastewater is adjusted with weak alkali, hydrogen peroxide is added to the preliminarily precipitated cyanide-removing wastewater after weak alkali adjustment, and the copper in the preliminarily precipitated cyanide-removing wastewater after weak alkali adjustment is used as a catalyst for an oxidation reaction to remove the remaining cyanide-containing pollutants; after the oxidation reaction is completed, lime is added for flocculation precipitation to obtain copper sludge, thereby realizing a single process flow. First, the cyanide in the cyanide copper wastewater reacts with ferrous ions to generate ferrocyanide ions, and through the Prussian blue reaction, it is converted into iron cyanide sludge, and the copper ions in the wastewater after subsequent cyanide removal are coagulated and precipitated to obtain copper sludge, thereby realizing the conversion of the copper cyanide compound in the cyanide copper wastewater into copper resources and cyanide resources that can be recycled respectively, and further realizing the recovery efficiency of various elemental resources in the cyanide copper wastewater, thereby improving the resource utilization rate of the cyanide copper wastewater.

[0092] It should be noted that the above examples are only for understanding the present application and do not constitute a limitation to the method for treating and resourcefully recycling electroplated cyanide copper wastewater of the present application. Based on this technical concept, more forms of simple transformations are within the protection scope of the present application.

[0093] The equipment for treating and resourcefully recycling electroplated cyanide copper wastewater provided by the present application adopts the method for treating and resourcefully recycling electroplated cyanide copper wastewater in the above embodiment, and can solve the technical problems of treating and resourcefully recycling electroplated cyanide copper wastewater. Compared with the prior art, the beneficial effects of the equipment for treating and resourcefully recycling electroplated cyanide copper wastewater provided by the present application are the same as those of the method for treating and resourcefully recycling electroplated cyanide copper wastewater provided by the above embodiment, and other technical features in the equipment for treating and resourcefully recycling electroplated cyanide copper wastewater are the same as the features disclosed in the method of the previous embodiment, and will not be elaborated here.

[0094] The above is only the specific embodiment of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed by the present application, and all should be covered by the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claimed rights.

[0095] The above is only a partial embodiment of the present application, and does not limit the patent scope of the present application. Any equivalent structural transformation made under the technical concept of the present application by using the content of the specification and drawings of the present application, or directly / indirectly applied in other related technical fields, is included in the patent protection scope of the present application.

[0096] It should be noted that in this text, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, such that a process, method, article or system comprising a series of elements not only includes those elements but also includes other elements not explicitly listed, or further includes elements inherent to such process, method, article or system. Without further limitation, an element defined by the statement "comprising an..." does not exclude the presence of additional identical elements in the process, method, article or system comprising such element.

[0097] The serial numbers of the embodiments of the present application above are only for description and do not represent the superiority or inferiority of the embodiments.

[0098] The above are only the preferred embodiments of the present application and do not limit the patent scope of the present application. Any equivalent structural or equivalent process transformation made by using the content of the specification and drawings of the present application, or directly or indirectly applied in other related technical fields, shall be equally included in the patent protection scope of the present application.

Claims

1. A method for treating electroplating cyanide copper wastewater and resource recovery, characterized in that, The method for treating and resourcefully recovering electroplated cyanide copper wastewater comprises the following steps: adjusting the cyanide copper wastewater with strong alkali, adding a ferrous sulfate solution to the cyanide copper wastewater after strong alkali adjustment for a combination reaction, and controlling the pH value of the solution during the entire combination reaction to be 10 - 11, so that the cyanide in the ferrous sulfate solution and the cyanide copper wastewater undergoes a combination reaction to generate ferrocyanide ions. Among them, the reaction time of the combination reaction is 1 - 2 h; adjusting the pH value of the cyanide copper wastewater after the combination reaction with acid, and performing a Prussian blue reaction when the pH value is 4.5 - 5.5, so that the ferrous ions in the cyanide copper wastewater after the combination reaction first react with the ferrocyanide ions, and the copper in the cyanide copper wastewater after the combination reaction is free in the solution; adding a coagulant aid into the solution after the Prussian blue reaction, and performing solid-liquid filtration separation to obtain iron cyanide sludge and preliminarily precipitated cyanide-removed wastewater. Among them, the iron cyanide sludge is used as a raw material for yellow prussiate of potash for resource treatment. Among them, the cyanide copper wastewater contains at least free cyanide and copper cyanide complex. According to the stability constant of the copper cyanide complex, the solubility product of ferrocyanate, and the pH value during the corresponding reaction, the ferrous ions first react with the cyanide radical in the copper cyanide complex, and then react with the copper ions in the copper cyanide complex, so that the cyanide radical is preferentially transferred and separated, and a precipitate of iron cyanide sludge is generated; adjusting the pH value of the preliminarily precipitated cyanide-removed wastewater with weak alkali, adding hydrogen peroxide to the preliminarily precipitated cyanide-removed wastewater after weak alkali adjustment, and using the copper in the preliminarily precipitated cyanide-removed wastewater after weak alkali adjustment as a catalyst for an oxidation reaction, and controlling the pH value of the solution during the entire oxidation reaction to be 6.5 - 7.5 to remove the remaining cyanide-containing pollutants. Among them, the reaction time of the oxidation reaction is 1 - 2 h; after the oxidation reaction is completed, adding lime for flocculation precipitation to obtain copper sludge, and the copper sludge is subjected to resource treatment subsequently.

2. The method according to claim 1, characterized in that, The reagent used for the strong alkali adjustment and the weak alkali adjustment is NaOH, and the mass concentration is 10% - 30%.

3. The method according to claim 1, wherein The mass concentration of the ferrous sulfate solution is 10% - 25%.

4. The method according to claim 1, wherein The reagent used for the acid adjustment is hydrochloric acid or sulfuric acid. The mass concentration of the hydrochloric acid is 10% - 30%, and the mass concentration of the sulfuric acid is 10% - 40%.

5. The method according to claim 1, characterized in that, The coagulant aid is polyaluminum chloride and / or polyacrylamide. Among them, the mass concentration of the polyaluminum chloride is 5 - 10%, and the mass concentration of the polyacrylamide is 0.5 - 1.0%.

6. The method according to claim 1, wherein The solid-liquid filtration separation method is plate-and-frame pressure filtration.

7. The method according to claim 1, wherein The mass concentration of the hydrogen peroxide is 7%.

8. The method according to claim 1, wherein The component of the lime is Ca(OH)₂, and the mass concentration is 10% - 20%.

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