Method for producing copper hydroxide by using electroplating sludge

Abstract

The invention provides a method for producing copper hydroxide by using electroplating sludge. The invention relates to a method for producing copper hydroxide by using electroplating sludge, which comprises the following steps: (1) pulpifying: adding slag washing water into a pulpifying tank, slowly adding the electroplating sludge into the pulpifying tank, and starting stirring at the liquid-solid ratio of (2.5-3): 1 and the temperature of 40-70 DEG C for 5-8 hours; according to the method, the filtrate obtained in the step (2) is pumped into the primary iron removal kettle through the pump, meanwhile, hydrogen peroxide and sodium carbonate are added into the iron removal kettle to adjust the PH value, oxidation neutralization and chemical precipitation can be carried out, and impurity metals such as iron and chromium contained in the filtrate are removed; meanwhile, filter residues generated by leaching and filter residues generated by primary iron removal enter a leaching residue washing kettle and an iron residue washing kettle respectively, residue washing water and sulfuric acid are pumped into the washing kettles, leaching residues and iron residues are subjected to acid pickling, and iron ions carried in the solution can be more sufficiently removed.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of electroplating sludge, and particularly relates to a method for producing copper hydroxide from electroplating sludge. BACKGROUND

[0002] The electroplating sludge is a precipitate mainly composed of heavy metal hydroxides such as copper and chromium, which is generated in the electroplating wastewater treatment process. The electroplating sludge has the characteristics of complex composition, high water content, high thermal stability and easy migration of heavy metal components. The electroplating sludge is mainly generated in the wastewater produced in the pretreatment, electroplating process and post-treatment process of the electroplating process. After the wastewater is treated by acid-base neutralization, flocculation and precipitation and other methods, the electroplating sludge is formed. If the electroplating sludge is discharged without treatment due to the presence of various heavy metal compounds and soluble salts, it will cause serious environmental pollution. Therefore, how to effectively treat the electroplating sludge to make it stable, harmless and resourceful has become an important issue in the current electroplating industry and environmental governance field. At present, the extraction of valuable metal ions contained in the electroplating sludge is not mature in China, and the impurity removal effect of the electroplating sludge solution is not good, which will cause waste of resources. Therefore, it is necessary to provide a method for producing copper hydroxide from electroplating sludge to solve the above problems. SUMMARY

[0003] The technical content of the application is to provide a method for producing copper hydroxide from electroplating sludge.

[0004] To solve the above problems, the application provides a method for producing copper hydroxide from electroplating sludge, which comprises the following steps: (1) slurry: adding washing water into a slurry tank, slowly adding electroplating sludge into the slurry tank, starting stirring, the liquid-solid ratio is 2.5-3:1, the temperature is 40-70℃, and the time is 5-8h; (2) leaching: pumping the slurry obtained in step (1) into a leaching kettle, starting stirring, slowly adding sulfuric acid into the leaching kettle from a high tank in a self-flowing manner, the PH is 1.0-2.5, the reaction temperature is 50-90℃, the reaction time is 4-6h, and after the leaching is completed, solid-liquid separation is performed through a filter press; (3) first iron removal: pumping the filtrate obtained in step (2) into a first iron removal kettle with a pump, starting stirring, slowly adding hydrogen peroxide into the iron removal kettle from a high tank in a self-flowing manner, while adding pure alkali to adjust the PH value, performing oxidation neutralization and chemical precipitation, removing the iron, chromium and other impurity metals contained in the filtrate, the reaction temperature is 50-90℃, the PH is 3.0-4.0, the reaction time is 2-5h, after the iron removal is completed, solid-liquid separation is performed through a filter press, the filtrate enters a copper extraction process, the filter residue produced in the leaching and the filter residue produced in the first iron removal enter a leaching residue washing kettle and an iron residue washing kettle respectively, washing water and sulfuric acid are pumped into the washing kettle to perform acid washing on the leaching residue and the iron residue, the PH is 1.0-2.5, the reaction temperature is 50-90℃, the reaction time is 1.5-3.0h, after the acid washing on the leaching residue and the iron residue is completed, solid-liquid separation is performed through a filter press, the filtrate returns to the slurry process, the filter residue enters a third countercurrent residue washing kettle to be washed with water, after the water washing is completed, the filter residue is pumped into a filter press to be filtered, the filtrate is pumped into a residue washing system for reuse, and the filter residue is temporarily stored; (4) copper extraction: the filtrate after the first iron removal is pumped into a copper extraction system to separate copper, nickel and chromium: the copper extraction agent Lix984 and sulfonated kerosene are uniformly mixed in a saponification tank according to a certain proportion, liquid sodium hydroxide is slowly added into the saponification tank from a high tank in a self-flowing manner to perform saponification, the saponified liquid is pumped into a copper extraction tank mixing chamber to be fully mixed with the filtrate after the first iron removal, and the extraction temperature is 30-50℃; (5) copper sulfate solution preparation: the solution obtained in step (4) is introduced into an extraction tank, and copper sulfate solution is obtained after the produced loaded organic sulfuric acid in step (4) is back extracted; (6) copper hydroxide preparation: the copper sulfate solution obtained in step (5) is pumped into a reaction kettle, liquid sodium hydroxide is slowly added into the reaction kettle from a high tank in a self-flowing manner to react with the copper sulfate solution to generate copper hydroxide, the reaction temperature is 50-80℃, the reaction time is 4-9h, after the reaction is completed, the reaction kettle is pumped into a filter press to be filtered, the filter residue is a crude copper hydroxide product, and the filtrate is pumped into a surface treatment center sewage treatment plant for treatment.

[0005] As a further solution of the application, the washing water in steps (1) and (3) can use tap water, and the electroplating sludge is generally bagged, which can be added into the slurry tank by a row of hangers.

[0006] As a further solution of the present application, the sulfuric acid in steps (2) and (3) needs to use a sulfuric acid solution with a concentration of 98%.

[0007] As a further solution of the present application, the loaded organic in step (5) is the solution generated by transferring the copper ion into the organic phase, the concentration of sulfuric acid used in step (5) is 15%, and the sulfuric acid is fed into the extraction tank from the head tank in a self-flowing manner.

[0008] Compared with the related art, the method for producing copper hydroxide from electroplating sludge provided by the present application has the following beneficial effects:

[0009] 1、The filtrate obtained in step (2) is pumped into the primary iron removal kettle, and hydrogen peroxide and sodium carbonate are added to the iron removal kettle to adjust the pH value, so that oxidation neutralization and chemical precipitation can be carried out, and the impurity metals such as iron and chromium contained in the filtrate can be removed, and the filter residue generated by leaching and the filter residue generated by primary iron removal are respectively introduced into the leaching residue washing kettle and the iron residue washing kettle, and washing residue water and sulfuric acid are pumped into the washing kettle to carry out pickling leaching residue and pickling iron residue, so that the iron ions carried in the solution can be more fully removed.

[0010] 2、The present application adds the copper extractant Lix984 and sulfonated kerosene mixed uniformly in a certain proportion to the filtrate after primary iron removal, and slowly adds liquid sodium hydroxide from the head tank to the saponification tank for saponification in a self-flowing manner, and then pumps the saponified liquid into the mixing chamber of the copper extraction tank and fully mixes with the filtrate after primary iron removal, so that the loaded organic solution carrying metal copper ions can be obtained, which is convenient for subsequent processes.

[0011] 3、The present application adds the copper extractant Lix984 and sulfonated kerosene mixed uniformly in a certain proportion to the filtrate after primary iron removal, and slowly adds liquid sodium hydroxide from the head tank to the saponification tank for saponification in a self-flowing manner, and then pumps the saponified liquid into the mixing chamber of the copper extraction tank and fully mixes with the filtrate after primary iron removal, so that the loaded organic solution carrying metal copper ions can be obtained, which is convenient for subsequent processes. DETAILED DESCRIPTION

[0012] A method for producing copper hydroxide from electroplating sludge, the method comprising the following steps: (1) slurry: adding wash water into the slurry tank, slowly adding electroplating sludge into the slurry tank, starting stirring, liquid-solid ratio is 2.5-3:1, temperature is 40-70℃, time is 5-8h; (2) leaching: pumping the slurry obtained in step (1) into the leaching kettle, starting stirring, slowly adding sulfuric acid into the leaching kettle from the high tank by gravity, PH is 1.0-2.5, reaction temperature is 50-90℃, reaction time is 4-6h, after leaching, solid-liquid separation is carried out by pressure filter; (3) first iron removal: pumping the filtrate obtained in step (2) into the first iron removal kettle by pump, starting stirring, slowly adding hydrogen peroxide into the iron removal kettle from the high tank by gravity, while adding pure alkali to adjust PH value, carrying out oxidation and neutralization and chemical precipitation, removing iron, chromium and other impurity metals contained in the filtrate, reaction temperature is 50-90℃, PH is 3.0-4.0, reaction time is 2-5h, after iron removal, solid-liquid separation is carried out by pressure filter, the filtrate enters the copper extraction process, the filter residue produced in leaching and the filter residue produced in first iron removal enter the leaching residue washing kettle and the iron residue washing kettle respectively, pumping wash water and sulfuric acid into the washing kettle, carrying out acid washing of the leaching residue and the iron residue, PH is 1.0-2.5, reaction temperature is 50-90℃, reaction time is 1.5-3.0h, after acid washing of the leaching residue and the iron residue, solid-liquid separation is carried out by pressure filter, the filtrate returns to the slurry process, the filter residue enters the third countercurrent residue washing kettle for water washing, after water washing, the filter residue is pumped into the pressure filter for pressure filtration, the filtrate is pumped into the residue washing system for reuse, and the filter residue is temporarily stored; (4) copper extraction: pumping the filtrate after first iron removal into the copper extraction system for copper, nickel and chromium separation: mixing copper extraction agent Lix984 and sulfonated kerosene in a certain proportion in the saponification tank, slowly adding liquid sodium hydroxide into the saponification tank from the high tank by gravity for saponification, pumping the saponified liquid into the mixing chamber of the copper extraction box and mixing with the filtrate after first iron removal, extraction temperature is 30-50℃; (5) copper sulfate solution preparation: pumping the solution obtained in step (4) into the extraction box, and obtaining copper sulfate solution after stripping the loaded organic sulfuric acid produced in step (4); (6) copper hydroxide preparation: pumping the copper sulfate solution obtained in step (5) into the reaction kettle, slowly adding liquid sodium hydroxide into the reaction kettle from the high tank by gravity, and chemically reacting with the copper sulfate solution to generate copper hydroxide, reaction temperature is 50-80℃, reaction time is 4-9h, after reaction, pressure filtration is carried out by pumping into the pressure filter, the filter residue is crude copper hydroxide product, and the filtrate is pumped into the surface treatment center sewage treatment plant for treatment.

[0013] Preferably, the wash water in steps (1) and (3) can use tap water, and the electroplating sludge is generally bagged, which can be added into the slurry tank by using a row of hangers;

[0014] Preferably, the sulfuric acid in steps (2) and (3) needs to use sulfuric acid solution with a concentration of 98%.

[0015] Preferably, the loaded organic in step (5) is transferred to the solution generated in the organic phase, the concentration of sulfuric acid used in step (5) is 15%, and the sulfuric acid is fed into the extraction tank from the head tank in a self-flowing manner.

[0016] The standard parts used in the embodiment can be directly purchased from the market, and can also be ordered according to the description in the specification. The specific connection mode of each part adopts the conventional means such as bolt, rivet and welding in the prior art. The mechanical, part and equipment adopt the conventional type in the prior art, and the components known to the person skilled in the art, the structure and principle thereof can be known by the person skilled in the art through the technical manual or through the conventional experimental method.

[0017] Although the embodiments of the present application have been shown and described, it is understood that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present application, and can be directly or indirectly applied in other related technical fields. The scope of the present application is defined by the appended claims and their equivalents, and the same applies to the patent protection scope of the present application.

Claims

1. A method for producing copper hydroxide from electroplating sludge, characterized in that, The method includes the following steps: (1) Pulping: Add slag washing water to the pulping tank, slowly add electroplating sludge to the pulping tank, start stirring, the liquid-solid ratio is 2.5-3:1, the temperature is 40℃-70℃, and the time is 5-8h. (2) Leaching: Pump the slurry obtained in step (1) into the leaching vessel, turn on the stirring, and slowly add sulfuric acid from the high-level tank into the leaching vessel by gravity. The pH is 1.0-2.5, the reaction temperature is 50℃-90℃, and the reaction time is 4-6h. After leaching, the solid and liquid are separated by a filter press. (3) Primary iron removal: The filtrate obtained in step (2) is pumped into the primary iron removal reactor. Stirring is started, and hydrogen peroxide is slowly added to the iron removal reactor from the high-level tank by gravity. At the same time, soda ash is added to adjust the pH value for oxidation neutralization and chemical precipitation to remove impurities such as iron and chromium from the filtrate. The reaction temperature is 50℃-90℃, the pH is 3.0-4.0, and the reaction time is 2-5 hours. After iron removal, the filtrate is separated into solid and liquid components by a filter press. The filtrate enters the copper extraction process. The filter residue produced by leaching and the primary iron removal product are separated. The raw filter residue is fed into the leaching residue washing tank and the iron slag washing tank respectively. Washing water and sulfuric acid are pumped into the washing tank to acid wash the leaching residue and iron slag. The pH is 1.0-2.5, the reaction temperature is 50℃-90℃, and the reaction time is 1.5-3.0h. After the acid washing of the leaching residue and iron slag is completed, solid-liquid separation is performed by a filter press. The filtrate is returned to the pulping process, and the filter residue is fed into a three-stage countercurrent slag washing tank for water washing. After water washing, it is pumped into a filter press for filtration. The filtrate is pumped into the slag washing system for reuse, and the filter residue is temporarily stored. (4) Copper extraction: The filtrate after the first iron removal is pumped into the copper extraction system for copper, nickel and chromium separation: the copper extractant Lix984 and sulfonated kerosene are mixed evenly in a saponification tank in a certain proportion. Liquid sodium hydroxide is slowly added to the saponification tank from the high-level tank by gravity flow for saponification. After saponification, the liquid is pumped into the mixing chamber of the copper extraction box and mixed thoroughly with the filtrate after the first iron removal. The extraction temperature is 30℃-50℃. (5) Preparation of copper sulfate solution: The solution obtained in step (4) is introduced into the extraction tank. The copper sulfate solution is obtained by back-extraction of the organic-loaded sulfuric acid produced in step (4). (6) Preparation of copper hydroxide: The copper sulfate solution obtained in step (5) is pumped into the reaction vessel. Liquid sodium hydroxide is slowly added to the copper sulfate solution by gravity in a high-level tank to produce copper hydroxide. The reaction temperature is 50℃-80℃ and the reaction time is 4-9h. After the reaction is completed, the solution is pumped into a filter press for filtration. The filter residue is crude copper hydroxide product. The filtrate is pumped into the wastewater treatment plant of the surface treatment center for treatment.

2. The method for producing copper hydroxide from electroplating sludge according to claim 1, characterized in that: The sludge washing water in steps (1) and (3) can be tap water. Electroplating sludge is usually in bags and can be added to the slurry tank using a crane.

3. The method for producing copper hydroxide from electroplating sludge according to claim 1, characterized in that: The sulfuric acid in steps (2) and (3) requires a 98% sulfuric acid solution.

4. The method for producing copper hydroxide from electroplating sludge according to claim 1, characterized in that: The loaded organic in step (5) is a solution generated by transferring copper ions into the organic phase. The sulfuric acid used in step (5) has a concentration of 15%, and the sulfuric acid is fed into the extraction tank from the high-level tank by gravity.