A method for preparing iron oxide red by using electroplating waste acid
Iron oxide red was prepared by modifying macroporous resin with ion-imprinted polymer and by neutralization precipitation, which solved the problem of poor selectivity in organic solvent extraction and achieved a high-purity, high-stability iron oxide red product suitable for industrial pigments.
Patent Information
- Application Number
- CN202610317389.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-03-16
- Publication Date
- 2026-06-19
AI Technical Summary
Existing organic solvent extraction methods suffer from poor selectivity and easy loss of extractant, resulting in high levels of impurities and poor color stability in iron oxide red products, making it difficult to meet the application requirements of high-quality industrial pigments.
Ion-imprinted polymer-modified macroporous resin was used as a solid-phase extractant. Imprinted vacancies and amine oxime groups that match ferric ions were introduced onto the resin surface through a chemical reaction to form a highly selective adsorbent material. Iron oxide red was prepared by neutralization precipitation.
It achieves highly selective separation of ferric ions, reduces the amount of organic solvent used, improves the purity and color stability of iron oxide red, and meets the high-quality requirements of industrial pigments.
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Abstract
Description
Technical Field
[0001] This invention belongs to the field of electroplating waste liquid treatment technology, specifically relating to a method for preparing iron oxide red using electroplating waste acid liquid. Background Technology
[0002] With rapid socio-economic development and the continuous deepening of industrialization, the demand for steel products is increasing, driving the continuous expansion of the electroplating industry. In the electroplating process, steel parts must undergo rigorous surface pretreatment before entering the plating bath. Pickling is a crucial step in removing oxide scale, rust, and stains from the steel substrate. This process typically uses strong acidic solutions such as hydrochloric acid and sulfuric acid as cleaning media. During repeated use, the acidity of the pickling solution gradually decreases, while the concentration of iron ions accumulates, eventually forming a large amount of highly acidic waste acid solution rich in ferrous or ferric ions.
[0003] If such waste acid is discharged directly without proper treatment, it will pose a threat to water bodies and soil. However, from the perspective of resource recycling, the iron content in this waste acid has high recovery value. If the iron resources can be efficiently separated and utilized at a high value, it can not only effectively alleviate the environmental pressure of waste acid treatment, but also provide economically valuable secondary raw materials for related industries.
[0004] Iron oxide red, as a stable and widely used inorganic pigment, has important applications in coatings, construction, rubber, and magnetic materials. Currently, recovering iron from iron-containing industrial wastewater and preparing iron oxide red has become one of the important technological pathways for achieving waste-to-waste treatment and resource regeneration.
[0005] However, electroplating waste acid solutions have a complex composition, typically containing not only iron as the main metal but also various heavy metal impurity ions such as chromium, nickel, copper, and zinc. When using organic solvent extraction to recover iron ions from such waste solutions, the following drawbacks exist: poor extraction selectivity, making it difficult to effectively suppress the co-extraction behavior of impurity ions; large organic phase usage, resulting in low extraction efficiency; and during the extraction-washing-back-extraction cycle, the extractant is prone to loss, degradation, or activity reduction, leading to a continuous decline in extraction performance. These drawbacks directly result in high impurity residue levels and poor color stability in the obtained iron oxide red product, making it difficult to meet the application requirements of high-quality industrial pigments. Summary of the Invention
[0006] The purpose of this invention is to provide a method for preparing iron oxide red using waste acid from electroplating, so as to solve the technical problems of poor selectivity and easy loss of extractant in the existing organic solvent extraction method.
[0007] The objective of this invention can be achieved through the following technical solutions: A method for preparing iron oxide red using waste acid from electroplating includes the following steps: Step 1: Add an oxidant to the electroplating waste acid solution to remove Fe from the waste acid solution. 2+ Oxidized to Fe 3+ The pH was adjusted to 2-4 to obtain pretreated electroplating waste acid solution; Step 2: Pass the pretreated electroplating waste acid solution through an adsorption column packed with solid phase extraction resin. After the column pass is completed, the first effluent is obtained. Then, the hydrochloric acid solution is passed through the adsorption column for elution treatment to obtain the second effluent. Step 3: Prepare ferric hydroxide colloid by neutralization precipitation of the second effluent, and then calcine the ferric hydroxide colloid to obtain iron oxide red.
[0008] Furthermore, in step one, the oxidant is one of air, oxygen, or hydrogen peroxide.
[0009] Furthermore, in step two, the pretreated electroplating waste acid solution is passed through a flow rate of 0.5-2.0 mL / min, a temperature of 25-40℃, and a pressure of 0.1-0.5 MPa.
[0010] Furthermore, in step two, the solid-phase extraction resin packing height is 28-35cm, and the adsorption column diameter is 2-5cm.
[0011] Furthermore, in step two, the hydrochloric acid solution is passed through at a flow rate of 1-5.0 mL / min, a temperature of 25-40℃, and a pressure of 0.1-0.5 MPa.
[0012] The solid-phase extraction resin is an ion-imprinted polymer-modified macroporous resin.
[0013] Furthermore, the raw materials for preparing the solid-phase extraction resin include acrylic acid monomer, pyridine-amine oxime quaternary ammonium salt monomer, ferric chloride, macroporous resin, acrylamide, ethylene glycol diglycidyl ether, and azobisisobutyronitrile.
[0014] Furthermore, the acrylic monomer is at least one selected from acrylic acid, ethyl acrylate, methyl methacrylate, and methacrylic acid.
[0015] Furthermore, the solid-phase extraction resin is prepared in the following steps: Premix a was prepared by uniformly mixing ferric chloride, pyridine-amine oxime quaternary ammonium salt monomer, and anhydrous ethanol. Acrylamide and acrylic acid monomer were added to premix a and stirred until homogeneous to obtain mixture A. Macroporous resin, dichloromethane, and ethylene glycol diglycidyl ether were mixed until homogeneous to obtain mixture B. Mixtures A and B were added to a hydrothermal reactor. Azobisisobutyronitrile (AIBN) was added to the hydrothermal reactor, and the mixture was sonicated for 5 min. The reaction was then carried out at 70-80℃ for 14-20 h. After the reaction was completed, the mixture was filtered, and the filter cake was washed with hydrochloric acid solution until no Fe was detected in the washing liquid.3+ The resin was then washed with distilled water until neutral and dried at 50°C to constant weight to obtain a solid-phase extraction resin.
[0016] To address the problems of high organic phase usage, poor selectivity, and low extraction efficiency in traditional organic solvent extraction methods, this invention uses macroporous resin as a matrix and introduces ion-imprinted polymers onto the surface of the macroporous resin through a chemical reaction. This forms imprinted cavities that are highly matched to the charge, size, and coordination geometry of ferric ions. At the same time, a amine oxime group is introduced as a specific chelating site, so that the final solid-phase extraction resin can have both high selective adsorption of ferric ions and avoid the problems of solvent extraction.
[0017] Furthermore, the pyridine-amine oxime quaternary ammonium salt monomer in the resin endows the material with excellent hydrophilicity, significantly improves the wettability of the aqueous phase, promotes the rapid diffusion of target ions into the imprinted cavity, thereby greatly shortening the adsorption equilibrium time and fully utilizing the strong coordination and capture ability of the amine oxime group for ferric ions.
[0018] Furthermore, the ratio of ferric chloride, pyridylamine oxime quaternary ammonium salt monomer, anhydrous ethanol, acrylamide, acrylic acid monomer, macroporous resin, dichloromethane, ethylene glycol diglycidyl ether, and azobisisobutyronitrile is 1.3-1.6g: 2.7g: 80-120mL: 2.5g: 2.5-4g: 15g: 10-20mL: 7-9g: 0.3-0.5g.
[0019] Furthermore, the macroporous resin is AB-8 macroporous adsorption resin or X-5 macroporous adsorption resin.
[0020] Furthermore, the concentration of the hydrochloric acid solution is 1-3 mol / L.
[0021] The pyridine-amine oxime quaternary ammonium salt monomer is the product of the quaternization reaction of pyridine-amine oxime compound and ethyl chloride acrylate, with a molar ratio of pyridine-amine oxime compound to ethyl chloride acrylate of 1:1-1.1.
[0022] Furthermore, the pyridine-amine oxime compound is 3-pyridyl amine oxime and / or 4-pyridyl amine oxime.
[0023] Furthermore, the preparation steps of the pyridine-amine oxime quaternary ammonium salt monomer are as follows: Ethyl chloride acrylate and hydroquinone were added to anhydrous acetone and stirred until homogeneous. An acetone solution of pyridine-amine oxime compound was added at 20-30°C. The temperature was raised to 45-55°C and the reaction was stirred for 6-8 hours. After the reaction was completed, the mixture was cooled to room temperature and filtered. The filter cake was washed with deionized water and dried to obtain the pyridine-amine oxime quaternary ammonium salt monomer.
[0024] Furthermore, the amount of hydroquinone used is 0.5-1.0% of the mass of ethyl chloride acrylate.
[0025] Furthermore, the process of preparing ferric hydroxide colloid by neutralization precipitation in step three is as follows: The pH of the second effluent was adjusted to 5.5-6.5 with ammonia, and the mixture was heated to 60-90℃ to react until no precipitate was formed.
[0026] Furthermore, the sintering method in step three is as follows: first, the temperature is programmed to rise to 500-600℃ at a rate of 10℃ / min, pre-sinter for 20-30 minutes, and then the temperature is programmed to rise to 900-1000℃ at a rate of 5℃ / min, and the temperature is held for sintering for 2-3 hours.
[0027] The beneficial effects of this invention are: This method uses electroplating waste acid as raw material and produces iron oxide red through a selective separation-purification-conversion process. The product exhibits good key indicators such as iron content, color difference, and oil absorption, achieving a high-value transformation from hazardous waste to industrial pigment. Compared to traditional organic extractants, it features high selectivity, low organic solvent consumption, and good recyclability of the solid-phase extraction resin. Detailed Implementation
[0028] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.
[0029] Obviously, the following description is merely some examples or embodiments of this application. Those skilled in the art can apply this application to other similar scenarios without any inventive effort. Furthermore, it is understood that although the effort involved in such development may be complex and lengthy, for those skilled in the art related to the content disclosed in this application, any changes to design, manufacturing, or production based on the technical content disclosed in this application are merely conventional technical means and should not be construed as insufficient disclosure of the content of this application.
[0030] However, there may be instances where unnecessary detailed descriptions are omitted. For example, detailed descriptions of well-known matters or repetitive descriptions of essentially the same structure may be omitted. This is to avoid making the following description unnecessarily lengthy and to facilitate understanding by those skilled in the art. Furthermore, the following description is provided to enable those skilled in the art to fully understand this application and is not intended to limit the subject matter of the claims.
[0031] Unless otherwise specified, all embodiments and optional embodiments of this application can be combined to form new technical solutions, and all technical features and optional technical features of this application can be combined to form new technical solutions.
[0032] The following is a detailed description with reference to specific examples.
[0033] Preparation Example 1
[0034] A solid-phase extraction resin is prepared by the following steps: Premixed solution a was prepared by mixing 1.3g ferric chloride, 2.7g pyridine-amine oxime quaternary ammonium salt monomer, and 80mL anhydrous ethanol. 2.5g acrylamide and 2.5g acrylic acid were added to premixed solution a and stirred until homogeneous to obtain mixture A. Mixture B was prepared by mixing 15g AB-8 macroporous adsorption resin, 10mL dichloromethane, and 7g ethylene glycol diglycidyl ether. Mixtures A and B were added to a hydrothermal reactor. 0.3g azobisisobutyronitrile was added to the reactor, and the mixture was sonicated for 5 minutes and then reacted at 70℃ for 14 hours. After the reaction, the mixture was filtered, and the filter cake was washed with 1mol / L hydrochloric acid solution until Fe was undetectable in the washing liquid. 3+ The resin was then washed with distilled water until neutral and dried at 50°C to constant weight to obtain a solid-phase extraction resin.
[0035] The preparation steps for pyridine-amine oxime quaternary ammonium salt monomers are as follows: 0.01 mol of ethyl chloride acrylate and hydroquinone were added to 100 mL of anhydrous acetone. The amount of hydroquinone was 0.5% of the mass of ethyl chloride acrylate. The mixture was stirred until homogeneous. A mixed solution consisting of 0.01 mol of 3-pyridylamine oxime and 20 mL of acetone was added at 20 °C. The temperature was raised to 45 °C and the mixture was stirred for 6 h. After the reaction was completed, the mixture was cooled to room temperature and filtered. The filter cake was washed with deionized water and dried to obtain the pyridylamine oxime quaternary ammonium salt monomer.
[0036] Preparation Example 2
[0037] A solid-phase extraction resin is prepared by the following steps: Premixed solution a was prepared by mixing 1.5g ferric chloride, 2.7g pyridine-amine oxime quaternary ammonium salt monomer, and 100mL anhydrous ethanol. 2.5g acrylamide and 3.0g acrylic acid were added to premixed solution a and stirred until homogeneous to obtain mixture A. Mixture B was prepared by mixing 15g X-5 macroporous adsorption resin, 15mL dichloromethane, and 8g ethylene glycol diglycidyl ether. Mixtures A and B were added to a hydrothermal reactor. 0.4g azobisisobutyronitrile was added to the reactor, and the mixture was sonicated for 5 minutes and then reacted at 75℃ for 18 hours. After the reaction, the mixture was filtered, and the filter cake was washed with 2mol / L hydrochloric acid solution until Fe was undetectable in the washing liquid. 3+The resin was then washed with distilled water until neutral and dried at 50°C to constant weight to obtain a solid-phase extraction resin.
[0038] The preparation steps for pyridine-amine oxime quaternary ammonium salt monomers are as follows: 0.01 mol of ethyl chloride acrylate and hydroquinone were added to 100 mL of anhydrous acetone. The amount of hydroquinone was 1.0% of the mass of ethyl chloride acrylate. The mixture was stirred until homogeneous. A mixed solution consisting of 0.011 mol of 4-pyridylamine oxime and 30 mL of acetone was added at 30 °C. The temperature was raised to 55 °C and the mixture was stirred for 8 h. After the reaction was completed, the mixture was cooled to room temperature and filtered. The filter cake was washed with deionized water and dried to obtain the pyridylamine oxime quaternary ammonium salt monomer.
[0039] Preparation Example 3
[0040] A solid-phase extraction resin is prepared by the following steps: Premixed solution a was prepared by mixing 1.6 g ferric chloride, 2.7 g pyridine-amine oxime quaternary ammonium salt monomer, and 120 mL anhydrous ethanol. 2.5 g acrylamide and 4 g acrylic acid were added to premixed solution a and stirred until homogeneous to obtain mixture A. Mixture B was prepared by mixing 15 g AB-8 macroporous adsorption resin, 20 mL dichloromethane, and 9 g ethylene glycol diglycidyl ether. Mixtures A and B were added to a hydrothermal reactor, along with 0.5 g azobisisobutyronitrile (AIBN). After sonication for 5 min, the mixture was reacted at 80 °C for 20 h. After the reaction, the mixture was filtered, and the filter cake was washed with 3 mol / L hydrochloric acid solution until Fe was undetectable in the washing liquid. 3+ The resin was then washed with distilled water until neutral and dried at 50°C to constant weight to obtain a solid-phase extraction resin.
[0041] The preparation steps for pyridine-amine oxime quaternary ammonium salt monomers are as follows: 0.01 mol of ethyl chloride acrylate and hydroquinone were added to 100 mL of anhydrous acetone. The amount of hydroquinone was 1.0% of the mass of ethyl chloride acrylate. The mixture was stirred until homogeneous. A mixed solution consisting of 0.011 mol of 3-pyridylamine oxime and 30 mL of acetone was added at 30 °C. The temperature was raised to 55 °C and the mixture was stirred for 8 h. After the reaction was completed, the mixture was cooled to room temperature and filtered. The filter cake was washed with deionized water and dried to obtain the pyridylamine oxime quaternary ammonium salt monomer.
[0042] Compare with Example 1
[0043] A solid-phase extraction resin is prepared by the following steps: 1.3g ferric chloride, 2.7g pyridine-amine oxime quaternary ammonium salt monomer, 80mL anhydrous ethanol, 2.5g acrylamide, and 2.5g acrylic acid were stirred and mixed evenly to obtain mixture A. 15g AB-8 macroporous adsorption resin, 10mL dichloromethane, and 7g ethylene glycol diglycidyl ether were mixed evenly to obtain mixture B. Mixtures A and B were added to a hydrothermal reactor. 0.3g azobisisobutyronitrile was added to the hydrothermal reactor. After sonication for 5 minutes, the reaction was carried out at 70℃ for 14 hours. After the reaction was completed, the mixture was filtered, and the filter cake was washed with 1mol / L hydrochloric acid solution until Fe could not be detected in the washing liquid. 3+ The resin was then washed with distilled water until neutral and dried at 50°C to constant weight to obtain a solid-phase extraction resin. The preparation process of the pyridine-amine oxime quaternary ammonium salt monomer was the same as in Preparation Example 1.
[0044] Compare with Example 2
[0045] A solid-phase extraction resin, which differs from Preparation Example 1 only in that the "pyridylamine oxime quaternary ammonium salt monomer" in Preparation Example 1 is replaced with an equal mass of "3-pyridylamine oxime".
[0046] Compare with Example 3
[0047] A solid-phase extraction resin, which differs from Preparation Example 1 only in that the pyridine-amine oxime quaternary ammonium salt monomer in Preparation Example 1 is removed.
[0048] Example 1
[0049] A method for preparing iron oxide red using waste acid from electroplating includes the following steps: Step 1: Introduce oxygen into the electroplating waste acid solution to remove Fe from the solution. 2+ Oxidized to Fe 3+ The pH was adjusted to 2 with sodium hydroxide to obtain a pretreated electroplating waste acid solution. Step 2: Pass the pretreated electroplating waste acid solution through an adsorption column packed with the solid-phase extraction resin of Preparation Example 1. The solid-phase extraction resin is packed to a height of 28 cm, and the adsorption column diameter is 2 cm. The flow rate of the pretreated electroplating waste acid solution is 0.5 mL / min, the temperature is 25 °C, and the pressure is 0.1 MPa. After passing through the column, the first effluent is obtained. Then, the hydrochloric acid solution is passed through the adsorption column for elution treatment to obtain the second effluent. The flow rate of the hydrochloric acid solution is 1 mL / min, the temperature is 25 °C, and the pressure is 0.1 MPa. Step 3: Prepare ferric hydroxide colloid by neutralization precipitation of the second effluent, and then calcine the ferric hydroxide colloid to obtain iron oxide red.
[0050] The process of preparing ferric hydroxide colloid by neutralization precipitation in step three is as follows: The pH of the second effluent was adjusted to 5.5 with ammonia, and the mixture was heated to 60°C to react until no precipitate was formed.
[0051] The sintering method in step three is as follows: first, the temperature is increased to 500℃ at a rate of 10℃ / min, pre-sintering for 20 minutes, then the temperature is increased to 900℃ at a rate of 5℃ / min, and the temperature is held for sintering for 2 hours.
[0052] Example 2
[0053] A method for preparing iron oxide red using waste acid from electroplating includes the following steps: Step 1: Introduce oxygen into the electroplating waste acid solution to remove Fe from the solution. 2+ Oxidized to Fe 3+ The pH was adjusted to 3 with sodium hydroxide to obtain a pretreated electroplating waste acid solution. Step 2: Pass the pretreated electroplating waste acid solution through an adsorption column packed with the solid-phase extraction resin from Preparation Example 1. The solid-phase extraction resin is packed to a height of 30 cm, and the adsorption column diameter is 3.5 cm. The flow rate of the pretreated electroplating waste acid solution is 1.0 mL / min, the temperature is 30 °C, and the pressure is 0.3 MPa. After passing through the column, the first effluent is obtained. Then, the hydrochloric acid solution is passed through the adsorption column for elution treatment to obtain the second effluent. The flow rate of the hydrochloric acid solution is 3.0 mL / min, the temperature is 30 °C, and the pressure is 0.3 MPa. Step 3: Prepare ferric hydroxide colloid by neutralization precipitation of the second effluent, and then calcine the ferric hydroxide colloid to obtain iron oxide red.
[0054] The process of preparing ferric hydroxide colloid by neutralization precipitation in step three is as follows: The pH of the second effluent was adjusted to 6.0 with ammonia, and the mixture was heated to 80°C to react until no precipitate was formed.
[0055] The sintering method in step three is as follows: first, the temperature is increased to 550℃ at a rate of 10℃ / min, pre-sintering for 25 minutes, then the temperature is increased to 950℃ at a rate of 5℃ / min, and the temperature is held for sintering for 2.5 hours.
[0056] Example 3
[0057] A method for preparing iron oxide red using waste acid from electroplating includes the following steps: Step 1: Introduce oxygen into the electroplating waste acid solution to remove Fe from the solution. 2+ Oxidized to Fe 3+ The pH was adjusted to 4 with sodium hydroxide to obtain a pretreated electroplating waste acid solution. Step 2: Pass the pretreated electroplating waste acid solution through an adsorption column packed with the solid-phase extraction resin of Preparation Example 1. The solid-phase extraction resin is packed to a height of 35 cm, and the adsorption column diameter is 5 cm. The flow rate of the pretreated electroplating waste acid solution is 2.0 mL / min, the temperature is 40 °C, and the pressure is 0.5 MPa. After passing through the column, the first effluent is obtained. Then, the hydrochloric acid solution is passed through the adsorption column for elution treatment to obtain the second effluent. The flow rate of the hydrochloric acid solution is 5.0 mL / min, the temperature is 40 °C, and the pressure is 0.5 MPa. Step 3: Prepare ferric hydroxide colloid by neutralization precipitation of the second effluent, and then calcine the ferric hydroxide colloid to obtain iron oxide red.
[0058] The process of preparing ferric hydroxide colloid by neutralization precipitation in step three is as follows: The pH of the second effluent was adjusted to 6.5 with ammonia, and the mixture was heated to 90°C to react until no precipitate was formed.
[0059] The sintering method in step three is as follows: first, the temperature is increased to 600℃ at a rate of 10℃ / min, pre-sintering for 30 minutes, and then increased to 1000℃ at a rate of 5℃ / min, and then held for sintering for 2-3 hours.
[0060] Example 4
[0061] A method for preparing iron oxide red using waste acid from electroplating is different from Example 1 except that the solid-phase extraction resin in Example 1 is replaced with an equal mass of the product obtained in Example 2.
[0062] Example 5
[0063] A method for preparing iron oxide red using waste acid from electroplating is different from Example 1 except that the solid-phase extraction resin in Example 1 is replaced with an equal mass of the product obtained in Example 3.
[0064] Example 6
[0065] A method for preparing iron oxide red using waste acid from electroplating is different from Example 2, except that the solid-phase extraction resin in Example 2 is replaced with an equal mass of the product obtained in Example 3.
[0066] Comparative Example 1
[0067] A method for preparing iron oxide red using waste acid from electroplating is different from Example 1 except that the solid-phase extraction resin in Example 1 is replaced with the product obtained in Control Example 1 of equal mass.
[0068] Comparative Example 2
[0069] A method for preparing iron oxide red using waste acid from electroplating is different from Example 1 except that the solid-phase extraction resin in Example 1 is replaced with the product obtained in Control Example 2 of equal mass.
[0070] Comparative Example 3
[0071] A method for preparing iron oxide red using waste acid from electroplating is different from Example 1 except that the solid-phase extraction resin in Example 1 is replaced with the product obtained in Control Example 3 of equal mass.
[0072] The methods for preparing iron oxide red from electroplating waste acid provided in Examples 1-6 and Comparative Examples 1-3 were used to treat iron-containing electroplating waste acid from a steel product manufacturing plant in Anhui Province. This waste acid had a pH of 1.5, a ferrous ion content of 55 g / L, a ferric ion content of 12 g / L, a copper ion content of 20 g / L, and a zinc ion content of 15 g / L. The iron oxide red products obtained in Examples 1 and 2 were tested for color, purity, aqueous suspension cation value, and loss on drying, according to the analytical methods for iron oxide pigments in GB / T1863-2008. The results are shown in Table 1. Table 1
[0073] As can be seen from the data recorded in Table 1, the iron oxide red obtained in Examples 1-6 is of higher quality than that obtained in Comparative Examples 1-3.
[0074] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.
[0075] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.
Claims
1. A method for preparing iron oxide red using waste acid from electroplating, characterized in that, Includes the following steps: Step 1: Add an oxidant to the electroplating waste acid solution to remove Fe from the waste acid solution. 2+ Oxidized to Fe 3+ The pH was adjusted to 2-4 to obtain pretreated electroplating waste acid solution; Step 2: Pass the pretreated electroplating waste acid solution through an adsorption column packed with solid phase extraction resin. After the column is passed through, the first effluent is obtained. The hydrochloric acid solution was eluted through an adsorption column to obtain the second effluent; Step 3: Prepare ferric hydroxide colloid by neutralization precipitation of the second effluent, and then calcine the ferric hydroxide colloid to obtain iron oxide red.
2. The method for preparing iron oxide red using waste electroplating acid solution according to claim 1, characterized in that, The solid-phase extraction resin is an ion-imprinted polymer-modified macroporous resin.
3. A method for preparing iron oxide red using waste electroplating acid solution according to claim 1 or 2, characterized in that, The raw materials for preparing the solid-phase extraction resin include acrylic acid monomer, pyridine-amine oxime quaternary ammonium salt monomer, ferric chloride, macroporous resin, acrylamide, ethylene glycol diglycidyl ether, and azobisisobutyronitrile.
4. The method for preparing iron oxide red using waste electroplating acid solution according to claim 3, characterized in that, The acrylic monomer is at least one of acrylic acid, ethyl acrylate, methyl methacrylate, and methacrylic acid.
5. The method for preparing iron oxide red using waste electroplating acid solution according to claim 1, characterized in that, The solid-phase extraction resin is prepared in the following steps: Premix a was prepared by uniformly mixing ferric chloride, pyridine-amine oxime quaternary ammonium salt monomer, and anhydrous ethanol. Acrylamide and acrylic acid monomer were added to premix a and stirred until homogeneous to obtain mixture A. Macroporous resin, dichloromethane, and ethylene glycol diglycidyl ether were mixed until homogeneous to obtain mixture B. Mixtures A and B were added to a hydrothermal reactor. Azobisisobutyronitrile (AIBN) was added to the hydrothermal reactor, and the mixture was sonicated for 5 min. The reaction was then carried out at 70-80℃ for 14-20 h. After the reaction was completed, the mixture was filtered, and the filter cake was washed with hydrochloric acid solution until no Fe was detected in the washing liquid. 3+ The resin was then washed with distilled water until neutral and dried at 50°C to constant weight to obtain a solid-phase extraction resin.
6. The method for preparing iron oxide red using waste electroplating acid solution according to claim 5, characterized in that, The ratio of ferric chloride, pyridinium oxime quaternary ammonium salt monomer, anhydrous ethanol, acrylamide, acrylic acid monomer, macroporous resin, dichloromethane, ethylene glycol diglycidyl ether, and azobisisobutyronitrile is 1.3-1.6g: 2.7g: 80-120mL: 2.5g: 2.5-4g: 15g: 10-20mL: 7-9g: 0.3-0.5g.
7. The method for preparing iron oxide red using waste electroplating acid solution according to claim 5, characterized in that, The macroporous resin is AB-8 macroporous adsorption resin or X-5 macroporous adsorption resin, and the concentration of the hydrochloric acid solution is 1-3 mol / L.
8. A method for preparing iron oxide red using waste electroplating acid solution according to claim 5, characterized in that, The pyridine-amine oxime quaternary ammonium salt monomer is the product of the quaternization reaction of pyridine-amine oxime compound and ethyl chloride acrylate, with a molar ratio of pyridine-amine oxime compound to ethyl chloride acrylate of 1:1-1.
1.
9. A method for preparing iron oxide red using waste electroplating acid solution according to claim 8, characterized in that, The pyridylamine oxime compound is 3-pyridylamine oxime and / or 4-pyridylamine oxime.
10. A method for preparing iron oxide red using waste electroplating acid solution according to claim 8, characterized in that, The preparation steps for the pyridine-amine oxime quaternary ammonium salt monomer are as follows: Ethyl chloride acrylate and hydroquinone were added to anhydrous acetone and stirred until homogeneous. An acetone solution of pyridine-amine oxime compound was added at 20-30°C. The temperature was raised to 45-55°C and the reaction was stirred for 6-8 hours. After the reaction was completed, the mixture was cooled to room temperature and filtered. The filter cake was washed with deionized water and dried to obtain the pyridine-amine oxime quaternary ammonium salt monomer.