Preparation method and application of mn-doped copper slag-based polymer-derived hollow porous microspheres

Abstract

The application discloses a preparation method of Mn-doped copper residue-based polymer-derived hollow porous microspheres, characterized in that manganese salt and copper residue powder are added into an oxalic acid solution, uniformly mixed to prepare slurry, the slurry is added dropwise into dimethyl silicone oil under stirring, and the mixture is aged at 55-65 DEG C for 12 hours under the action of mechanical stirring force, then solid-liquid separation is performed, and the solid is calcined at 550-650 DEG C to prepare the Mn-doped copper residue-based polymer-derived hollow porous microspheres; the prepared catalyst is applied to adsorption-photocatalytic degradation of antibiotics, and experimental results show that the material has good adsorption-photocatalytic degradation performance on antibiotics; the catalyst has magnetism, is easy to separate, recycle and reuse, and the application improves the comprehensive utilization rate of copper residue and provides a new idea for treatment of organic pollutants.

Description

Technical Field

[0001] This invention relates to a method for preparing and applying Mn-doped copper smelting slag-derived hollow porous microspheres derived from macropolymers, belonging to the fields of solid waste resource utilization and photocatalytic treatment. Background Technology

[0002] Copper is an essential metal in daily life, commonly used in construction, power, and transportation. With advancements in science and technology and the increasing demands of modern life, copper production continues to rise annually. Currently, over 80% of global copper production is obtained through pyrometallurgical processes using copper sulfide concentrates. The smelting process inevitably produces residues, known as copper slag. Copper slag contains trace amounts of toxic elements and heavy metals. Its chemical composition is influenced by the smelting process, ore, solvents, and additives. Under different smelting processes, it almost always contains significant amounts of iron (30-45%), silicon (15-35%), and other substances. The chemical composition of copper slag varies depending on the copper smelting industry. The main mineral phases in copper slag are magnetite (Fe3O4) and fritillary olivine (Fe2SiO4), primarily composed of oxides such as Fe2O3, SiO2, Al2O3, and CaO. Fe2O3 content reaches as high as 55.72%, and SiO2 content reaches 32.24%. The copper smelting process generates tens of millions of tons of copper slag annually. The seepage of harmful substances during slag accumulation pollutes water resources and the environment, while fine particulate dust pollutes the atmosphere and harms health. Given my country's high dependence on imported iron ore and other valuable metal resources, strengthening the high-value utilization of copper slag at the end of its production process and transforming it into economically valuable products can not only compensate for resource shortages but also alleviate environmental pressures.

[0003] Photocatalysis technology has proven to be an effective method for treating organic pollutants due to its advantages of high efficiency, simplicity, environmental friendliness, and economy. It can achieve complete mineralization of organic pollutants under ambient temperature and atmospheric pressure conditions, while simultaneously producing low-toxicity byproducts. With sufficient light energy, electrons and holes can be generated simultaneously, allowing photocatalysts to achieve both oxidation and reduction in a single reaction system. Fe2O3 has been widely used in photocatalysis due to its high chemical stability, low cost, and non-toxicity. However, pure Fe2O3 still presents some challenges: firstly, powdered Fe2O3 is difficult to recover; secondly, photogenerated carriers easily recombine, leading to low photocatalytic efficiency; and thirdly, its limited light absorption capacity results in relatively low catalytic efficiency. Summary of the Invention

[0004] To address the problems existing in the prior art, this invention provides a method for preparing Mn-doped copper slag-based polymer-derived hollow porous microspheres. Using copper slag as raw material, manganese salt and copper slag powder are added to an oxalic acid solution and mixed to obtain a slurry. Under stirring conditions, the slurry is dropped into dimethyl silicone oil, and spheres are formed under the action of stirring mechanical force. The mixture is then aged at 55-65℃ for 12 hours, followed by solid-liquid separation. The solid is calcined at 550-650℃ to obtain Mn-doped copper slag-based polymer-derived hollow porous microspheres. The photocatalyst prepared by this invention not only has controllable particle size and is magnetic, but is also easy to separate, recover, and reuse, solving the problems of difficult recovery of pure Fe2O3 and low photocatalytic efficiency.

[0005] The preparation process of Mn-doped copper slag-based polymer-derived hollow porous microspheres is as follows:

[0006] (1) After drying the copper slag, grind it in a roller ball mill and pass it through a 200-mesh sieve. The residue on the sieve should be less than 5%.

[0007] The copper slag powder is obtained by grinding dry copper slag through a 200-mesh sieve, with a sieve residue of less than 5%; the main components of the copper slag are: Fe2O3 55-60wt%, SiO2 30-35wt%, MgO 1-2wt%, Al2O3 5-6wt%, CaO 2-3wt%, ZnO 2-3wt%.

[0008] (2) Weigh out oxalic acid and add it to deionized water and stir evenly. Add manganese salt and copper slag powder and mix evenly to obtain a slurry. The mass ratio of oxalic acid to copper slag is 1-1.5:1, the mass ratio of copper slag to manganese salt is 4-8:1, and the mass ratio of oxalic acid to water is 1.5-2:1.

[0009] (3) Under stirring conditions, the slurry was added dropwise to dimethyl silicone oil and formed into balls under the action of stirring mechanical force. Then the mixture was aged at 55-65℃ for 12h, and the solid and liquid were separated. The solid was calcined at 550-650℃ to obtain Mn-doped copper slag-based polymer-derived hollow porous microspheres.

[0010] Another objective of this invention is to apply the Mn-doped copper slag-based polymer-derived hollow porous microspheres prepared by the above method to the photocatalytic degradation of chlortetracycline hydrochloride.

[0011] Compared with the prior art, the advantages and beneficial effects of the present invention are as follows:

[0012] 1. The preparation method of this composite material is acid-activated suspension polymerization, which is simple to operate, has low production cost, and uses readily available raw materials. Fe ions are derived from copper slag. Oxalic acid is used to leach Fe ions from the copper slag, and suspension polymerization is used to form ferrous oxalate microspheres. Calcination generates Fe2O3 microspheres. When manganese sulfate monohydrate is added during the formation of ferrous oxalate, a series of characterization experiments show that Mn has been incorporated into the Fe2O3 derived from the copper slag geopolymer. The doping of Mn results in the presence of oxygen vacancies, which significantly enhances the catalytic efficiency and promotes the degradation of organic pollutants.

[0013] 2. Mn-doped copper slag-based polymer-derived hollow porous microspheres, due to their porous spatial structure, allow light to be fully adsorbed through multiple light reflections between the micropores. The hollow structure also facilitates the catalyst's absorption of light sources and release of oxygen free radicals. . Furthermore, the structure and magnetism of the microspheres also facilitate recycling;

[0014] 3. Mn-doped copper slag-based polymer-derived hollow porous microspheres have high redox properties due to the presence of oxygen vacancies. When applied to the removal of chlortetracycline, the degradation rate of chlortetracycline is 84.45% to 98.3%, which can effectively reduce the harm of organic pollutants to the environment. Attached Figure Description

[0015] Figure 1 XRD patterns of the CS-Fe2O3 catalyst and the Mn4 / CS-Fe2O3 catalyst prepared in Example 1;

[0016] Figure 2 SEM images of the CS-Fe2O3 catalyst (a, b) and Mn4 / CS-Fe2O3 catalyst (c, d) prepared in Example 1;

[0017] Figure 3 EDS diagram of the Mn4 / CS-Fe2O3 catalyst prepared in Example 1;

[0018] Figure 4 UV-Vis diffuse reflectance spectra (left) and band gap energy diagrams (right) of the CS-Fe2O3 catalyst and Mn4 / CS-Fe2O3 catalyst prepared in Example 1;

[0019] Figure 5 The graph shows the removal effect of chlortetracycline hydrochloride by the CS-Fe2O3 catalyst and the Mn4 / CS-Fe2O3 catalyst prepared in Example 1. Detailed Implementation

[0020] The present invention will be further described in detail below through examples. These examples are only used to illustrate the present invention and do not limit the scope of protection of the present invention. The main components of the copper slag used in the examples are: Fe2O3 55.72wt%, SiO2 32.24wt%, MgO 1.26wt%, Al2O3 5.17wt%, CaO 2.20wt%, and ZnO 2.66wt%.

[0021] Example 1:

[0022] 1. Weigh 5g of oxalic acid and add it to 2.6g of deionized water and stir evenly. Then add 0.5g of manganese sulfate monohydrate, mix well, and add 4g of copper slag to react with it until it reaches a slurry state. Quickly use a syringe to draw up the mixture and inject it into dimethyl silicone oil at room temperature. Stir it into balls at 800rpm for 4min using a disperser. Aging it in an oven at 60℃ for 12h, then separate the solid and liquid. Place the solid in a muffle furnace and calcine it at 600℃ for 2h to obtain Mn-doped copper slag-based polymer-derived hollow porous microspheres Mn / CS-Fe2O3.

[0023] Meanwhile, a CS-Fe2O3 catalyst was prepared as a control. 5g of oxalic acid was weighed and added to 2.55g of deionized water and stirred evenly. 4g of copper slag was added and reacted with it until it reached a slurry state. The mixture was quickly drawn up with a syringe and injected into dimethyl silicone oil at room temperature. The mixture was stirred into balls at 800rpm for 4min using a disperser. Then it was aged in an oven at 60℃ for 12h. The solid and liquid were separated, and the solid was calcined in a muffle furnace at 600℃ for 2h to obtain the CS-Fe2O3 catalyst.

[0024] The crystal structures of CS-Fe2O3 catalyst and Mn4 / CS-Fe2O3 catalyst are shown below. Figure 1 The XRD patterns show that the main components of the CS-Fe2O3 catalyst and the Mn4 / CS-Fe2O3 catalyst are Fe2O3, with no other impurity peaks observed. Furthermore, the peaks shifted after Mn doping.

[0025] The macroscopic morphologies of the CS-Fe2O3 catalyst and the Mn4 / CS-Fe2O3 catalyst are shown below. Figure 2 As can be seen from the figure, the morphology of the CS-Fe2O3 catalyst is a porous microsphere. Mn has been doped into the microspheres in the Mn4 / CS-Fe2O3 catalyst, resulting in oxygen vacancies in the original Fe2O3 porous microspheres. EDS analysis shows that O, Si, Mn, and Fe elements are relatively uniformly distributed in the Mn / CS-Fe2O3 catalyst. Figure 3 );

[0026] The optical properties of CS-Fe2O3 and Mn4 / CS-Fe2O3 catalysts were studied using UV-Vis diffuse reflectance analysis, and the results are as follows: Figure 4As shown in the figure, CS-Fe2O3 has good light absorption capacity in the wavelength range below 450nm. When doped with manganese sulfate monohydrate, the light absorption capacity of Mn / CS-Fe2O3 catalyst is significantly improved, indicating that Mn doping can effectively improve the visible light absorption capacity of CS-Fe2O3 catalyst.

[0027] 2. The CS-Fe2O3 catalyst and Mn4 / CS-Fe2O3 catalyst prepared in step 1 were used in the photoreactive removal of chlortetracycline hydrochloride (CTC). The catalyst dosage was 40 mg, and the concentration of chlortetracycline hydrochloride solution in 40 mL was 20 mg / L. The treatment was carried out under natural light for 60 min and under darkness for 30 min. The results are shown in […]. Figure 5 ,from Figure 5 It can be seen that when Mn is doped, the composite material significantly improves the removal efficiency of CTC. At 60 min, the degradation rate of CTC by the CS-Fe2O3 catalyst is 71.8%, while the degradation rate of CTC by the Mn4 / CS-Fe2O3 catalyst reaches 98.3%.

[0028] Example 2:

[0029] Weigh 5g of oxalic acid and add it to 2.58g of deionized water and stir well. Then add 0.25g of manganese sulfate monohydrate, mix well, and add 4g of copper slag to react with it until it reaches a slurry state. Quickly use a syringe to draw up the mixture and inject it into dimethyl silicone oil at room temperature. Stir it into balls at 800rpm for 4min using a disperser. Aging it in an oven at 60℃ for 12h, then separate the solid and liquid. Place the solid in a muffle furnace and calcine it at 600℃ for 2h to obtain Mn-doped copper slag-based polymer-derived hollow porous microsphere catalyst.

[0030] The catalyst prepared by the above method was used in the photoreactive removal of chlortetracycline hydrochloride (CTC). The amount of catalyst used was 40 mg, and the concentration of chlortetracycline hydrochloride solution in 40 mL was 20 mg / L. When the catalyst reacted under natural light for 60 min, the removal rate of chlortetracycline hydrochloride was about 77.05%.

[0031] Example 3:

[0032] Weigh 5g of oxalic acid and add it to 2.65g of deionized water and stir well. Then add 0.75g of manganese sulfate monohydrate, mix well, and add 4g of copper slag to react with it until it reaches a slurry state. Quickly use a syringe to draw up the mixture and inject it into dimethyl silicone oil at room temperature. Stir it into balls at 800rpm for 4min using a disperser. Aging it in an oven at 60℃ for 12h, then separate the solid and liquid. Place the solid in a muffle furnace and calcine it at 600℃ for 2h to obtain Mn-doped copper slag-based polymer-derived hollow porous microspheres.

[0033] The catalyst prepared by the above method was used in the photoreactive removal of chlortetracycline hydrochloride (CTC). The amount of catalyst used was 40 mg, and the concentration of chlortetracycline hydrochloride solution in 40 mL was 20 mg / L. When the catalyst reacted under natural light for 60 min, the removal rate of chlortetracycline hydrochloride was about 86.92%.

[0034] Example 4:

[0035] Weigh 5g of oxalic acid and add it to 2.7g of deionized water and stir well. Then add 1g of manganese sulfate monohydrate, mix well, and add 4g of copper slag to react with it until it reaches a slurry state. Quickly use a syringe to draw up the mixture and inject it into dimethyl silicone oil at room temperature. Stir it into balls at 800rpm for 4min using a disperser. Aging it in an oven at 60℃ for 12h, then separate the solid and liquid. Place the solid in a muffle furnace and calcine it at 600℃ for 2h to obtain Mn-doped copper slag-based polymer-derived hollow porous microspheres.

[0036] The catalyst prepared by the above method was used in the photoreactive removal of chlortetracycline hydrochloride (CTC). The amount of catalyst used was 40 mg, and the concentration of chlortetracycline hydrochloride solution in 40 mL was 20 mg / L. When the catalyst reacted under natural light for 60 min, the removal rate of chlortetracycline hydrochloride was about 84.45%.

Claims

1. A method for preparing Mn-doped copper slag-based polymer-derived hollow porous microspheres for photocatalytic degradation of chlortetracycline hydrochloride, characterized in that: Manganese salt and copper slag powder were added to oxalic acid solution and mixed to obtain a slurry. Under stirring conditions, the slurry was dropped into dimethyl silicone oil and formed into spheres under the action of stirring mechanical force. The mixture was then aged at 55-65℃ for 12 hours, and the solid and liquid were separated. The solid was calcined at 550-650℃ to obtain Mn-doped copper slag-based polymer-derived hollow porous microspheres. The main components of the copper slag are Fe2O3 55-60wt%, SiO2 30-35wt%, MgO 1-2wt%, Al2O3 5-6wt%, CaO 2-3wt%, and ZnO 2-3wt%.

2. The preparation method according to claim 1, characterized in that: The mass ratio of oxalic acid to copper slag is 1-1.5:1, the mass ratio of copper slag to manganese salt is 4-8:1, and the mass ratio of oxalic acid to water is 1.5-2:

1.

3. The preparation method according to claim 1, characterized in that: Copper slag powder is obtained by grinding dried copper slag through a 200-mesh sieve, with a residue of less than 5%.

4. The preparation method according to claim 1, characterized in that: The stirring speed is 700-900 rpm.

5. The application of the Mn-doped copper slag-based polymer-derived hollow porous microspheres prepared by the method according to any one of claims 1-4 in the photocatalytic degradation of chlortetracycline hydrochloride.

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