A method for preparing oleophilic ceramsite material for industrial wastewater treatment

Abstract

The present invention relates to the fields of oil-water separation and sewage treatment, and in particular to a method for preparing an oleophilic ceramsite material for industrial sewage treatment, comprising: (1) weighing blast furnace slag, iron tailings powder, waste activated carbon powder and river sand according to a weight ratio, placing them in a ball mill and fully mixing them to obtain a mixed powder; (2) adding silicon dioxide nano hollow spheres, mixing them, and then adding water glass and fully mixing them to obtain a ceramsite body; (3) placing the prepared ceramsite body in a muffle furnace for staged sintering; (4) preparing a catalyst precursor solution; (5) placing the sintered ceramsite body in a catalyst precursor solution in a vacuum tank, and then acid-washing to remove the silicon dioxide nano hollow spheres to obtain a modified ceramsite; (6) drying the obtained modified ceramsite, and then placing it in an atmosphere furnace for heat preservation to obtain an oleophilic ceramsite. The method obtains a stable oleophilic structure by regulating the electronic structure and optimizing the adsorption energy of the intermediate through the synergistic effect of Fe and Co.

Description

Technical Field

[0001] The invention relates to the fields of oil-water separation and sewage treatment, and in particular to a method for preparing an oleophilic ceramsite material for industrial sewage treatment. Background Art

[0002] Oil-water separation is crucial in industrial production, directly linked to environmental protection and the efficient use of resources. Traditional oil-water separation methods include gravity separation, filtration, membrane separation, electroaggregation, adsorption, chemical demulsification, and biological methods. Oil skimmers have long been a primary tool for treating oil-water mixtures.

[0003] However, these traditional methods have many shortcomings. For example, the skimmers have low processing efficiency and low oil removal rates, and the scrapped felt is classified as hazardous waste, which increases the environmental burden.

[0004] Compared to traditional methods, oleophilic ceramsite offers significant advantages. First, it boasts high separation efficiency, enabling rapid and efficient separation of oil-water mixtures, significantly improving treatment efficiency. Second, the use of oleophilic ceramsite can also reduce environmental pollution, as it can accomplish the separation task without the addition of additional chemicals. Furthermore, these ceramsites offer rapid separation speeds, enabling the completion of large oil-water separations in a short period of time.

[0005] More importantly, oleophilic ceramsite also has good recyclability, which means that they can remain efficient after multiple uses and can be used stably in extreme environments.

[0006] Chinese patent application number 201611026611.9 discloses a "ceramsite with oleophilic properties and its preparation method." This method involves post-processing and purifying the resulting ceramsite, then immersing it in a modification solution primarily composed of an aluminate coupling agent, water, and ethanol for loading and modification, followed by drying to obtain oleophilic ceramsite. However, this method uses a mixed solution of an aluminate coupling agent and ethanol for surface modification during the immersion process, rather than enhancing bonding through chemical bonding or crystal doping. This can lead to coating shedding and other issues during long-term use, making the oleophilic properties unstable. Summary of the Invention

[0007] In order to overcome the defects of the existing technology, the technical problem solved by the present invention is to provide a method for preparing an oleophilic ceramsite material for industrial wastewater treatment. In this method, a salt solution of catalysts Fe and Co is added to prepare a catalyst precursor solution. The electronic structure is regulated and the adsorption energy of the intermediate is optimized through the synergistic effect of Fe and Co, thereby significantly improving the reaction activity and stability of the catalyst, thereby obtaining a stable oleophilic structure.

[0008] In order to achieve the above object, the present invention adopts the following technical solutions:

[0009] A method for preparing an oleophilic ceramsite material for industrial wastewater treatment comprises the following steps:

[0010] (1) Weigh blast furnace slag, iron tailings powder, waste activated carbon powder and river sand according to the weight ratio, place them in a ball mill, fully mix them and ball mill them to 200 mesh, then remove metal impurities by magnetic separation, and then dry them to obtain a mixed powder;

[0011] The weight ratio of the blast furnace slag, iron tailings powder, waste activated carbon powder and river sand is: 40-60 parts of blast furnace slag, 15-30 parts of iron tailings powder, 10-20 parts of waste activated carbon powder and 5-10 parts of river sand;

[0012] (2) adding hollow silicon dioxide nanospheres to the mixed powder, adding water glass after mixing and fully mixing, then granulating the mixture through a granulator and drying it at room temperature to obtain a ceramsite body;

[0013] The mass ratio of the mixed powder to the hollow silica nanospheres is 1:(4-6); the mass ratio of the mixed powder to the water glass is 10:(1.5-2);

[0014] (3) The prepared ceramsite body is placed in a muffle furnace for staged sintering: pretreatment stage: keep at 150-180 °C for 1-3 hours; high temperature sintering stage: keep at 550-750 °C for 1-3 hours; finally cool to room temperature;

[0015] (4) Mixing sodium carboxymethyl cellulose with a mass fraction of 0.1-1 wt% and isobutylene-maleic anhydride copolymer in a mass ratio of 1:(1-3) to obtain a protective agent solution; adding a salt solution of catalysts Fe and Co to the protective agent solution to prepare a catalyst precursor solution; wherein the Fe and Co salts are mixed in a molar ratio of (0.8-1.2):1 to prepare a catalyst precursor solution with a total metal concentration of 0.01-0.2 wt%;

[0016] (5) The sintered ceramsite body is placed in a catalyst precursor solution in a vacuum tank, and the pressure in the vacuum tank is maintained at 0.08-0.1 MPa for 1-2 h. After returning to normal pressure, the body is allowed to stand for 2-4 h. The hollow silica nanospheres are then removed by pickling with a 1 mol / L HF solution for 10-30 min to obtain the modified ceramsite.

[0017] (6) The modified ceramsite is dried at 110-130°C for 12-15 hours, and then placed in an atmosphere furnace at 250-400°C for 2-3 hours to obtain oleophilic ceramsite.

[0018] In the step (1), the ball mill is a double-roller ball mill; and the drying temperature is 90-110°C.

[0019] In the step (1), the mass percentage of SiO2 in the iron tailings powder is 75%.

[0020] In the step (2), the granulator is a disc granulator, and the drying time at room temperature is 12 to 15 hours.

[0021] In the step (2), the modulus of the water glass is 1.5-2.

[0022] In the step (2), the particle size of the hollow silica nanospheres is 150-200 nm.

[0023] In the step (6), the atmosphere in the atmosphere furnace includes argon, nitrogen or argon-hydrogen mixed gas.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] 1) The present invention uses hollow silicon oxide nanospheres as a template, which increases the specific surface area of ​​the ceramsite and provides more channels and spaces for the adsorption of oil substances, thereby improving the lipophilic adsorption performance of the ceramsite.

[0026] 2) The present invention uses a salt solution of Fe and Co as a catalyst, which has significant cost advantages. The synergistic effect of Fe and Co regulates the electronic structure and optimizes the adsorption energy of the intermediate, significantly improving the reaction activity and stability of the catalyst and facilitating the formation of lipophilic structures.

[0027] 3) The present invention adopts staged sintering (pretreatment stage + high-temperature sintering stage) to avoid structural collapse and balance porosity and mechanical strength; combined with vacuum impregnation, it ensures that the catalyst precursor solution is evenly loaded on the pore surface, and ultimately obtains oleophilic ceramsite with an oil contact angle of less than 40°.

[0028] 4) The present invention uses industrial wastes such as blast furnace slag, iron tailings, and waste activated carbon as the main raw materials, which not only reduces production costs but also realizes the resource utilization of solid waste and reduces the environmental burden. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The accompanying drawings, which constitute part of the present invention, are provided to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are provided to explain the present invention and do not constitute an undue limitation of the present invention. In the accompanying drawings:

[0030] Figure 1 Schematic diagram of the oil wetting angle of the oleophilic ceramsite in Example 1 of the present invention. DETAILED DESCRIPTION

[0031] The specific embodiments of the present invention are further described below:

[0032] Example 1:

[0033] A method for preparing an oleophilic ceramsite material for industrial wastewater treatment comprises the following steps:

[0034] (1) Blast furnace slag, iron tailings powder, waste activated carbon powder and river sand were weighed according to the weight ratio, placed in a double-roller ball mill, fully mixed and ball-milled to 200 mesh, and then magnetically separated to remove metal impurities, and then dried at a temperature of 105°C to obtain a mixed powder; the mass percentage of SiO2 in the iron tailings powder was ≥75%.

[0035] Among them, the weight ratio of blast furnace slag, iron tailings powder, waste activated carbon powder and river sand is: 42 parts of blast furnace slag, 16 parts of iron tailings powder, 11 parts of waste activated carbon powder and 6 parts of river sand.

[0036] (2) Adding hollow silicon dioxide nanospheres to the mixed powder, adding water glass after mixing and mixing thoroughly, and then granulating it through a disc granulator and drying it at room temperature for 12 hours to obtain a ceramsite body.

[0037] The mass ratio of the mixed powder to the hollow silica nanospheres was 1:4, and the mass ratio of the mixed powder to water glass was 10:1.5. The modulus of the water glass was 1.5, and the particle size of the hollow silica nanospheres was 150-200 nm.

[0038] (3) The prepared ceramsite body is placed in a muffle furnace for staged sintering: pretreatment stage: keep at 160 ° C for 1.5 hours; high temperature sintering stage: keep at 600 ° C for 2 hours; finally cool to room temperature;

[0039] (4) Sodium carboxymethyl cellulose with a mass fraction of 0.1 wt% and isobutylene-maleic anhydride copolymer were mixed in a mass ratio of 1:1 to obtain a protective agent solution; salt solutions of catalysts Fe and Co were added to the protective agent solution, and Fe and Co salts were mixed in a molar ratio of 0.8:1 to prepare a catalyst precursor solution with a total metal concentration of 0.01 wt%.

[0040] (5) The ceramsite green body after staged sintering was placed in a catalyst precursor solution in a vacuum tank. The pressure in the vacuum tank was maintained at 0.08~0.1MPa for 1 hour. After returning to normal pressure, it was allowed to stand for 3 hours. Then, the hollow silica nanospheres were removed by pickling with 1mol / LHF solution for 20 minutes to obtain modified ceramsite.

[0041] (6) The modified ceramsite was dried at 110°C for 13 h, and then placed in an atmosphere furnace at 250°C for 2 h to obtain oleophilic ceramsite. The atmosphere in the atmosphere furnace was argon.

[0042] Example 2:

[0043] A method for preparing an oleophilic ceramsite material for industrial wastewater treatment comprises the following steps:

[0044] (1) Blast furnace slag, iron tailings powder, waste activated carbon powder and river sand were weighed according to the weight ratio, placed in a double-roller ball mill, fully mixed and ball-milled to 200 mesh, and then magnetically separated to remove metal impurities, and then dried at a temperature of 110°C to obtain a mixed powder; the mass percentage of SiO2 in the iron tailings powder was ≥75%.

[0045] Among them, the weight ratio of blast furnace slag, iron tailings powder, waste activated carbon powder and river sand is: 55 parts of blast furnace slag, 20 parts of iron tailings powder, 16 parts of waste activated carbon powder and 7 parts of river sand.

[0046] (2) Adding hollow silicon dioxide nanospheres to the mixed powder, adding water glass after mixing and mixing thoroughly, then granulating it through a disc granulator and drying it at room temperature for 13 hours to obtain a ceramsite body.

[0047] The mass ratio of the mixed powder to the hollow silica nanospheres is 1:5, and the mass ratio of the mixed powder to water glass is 10:1.8. The modulus of the water glass is 2, and the particle size of the hollow silica nanospheres is 150-200 nm.

[0048] (3) The prepared ceramsite body is placed in a muffle furnace for staged sintering: pretreatment stage: keep at 170 ° C for 1.5 hours; high temperature sintering stage: keep at 700 ° C for 2 hours; finally cool to room temperature;

[0049] (4) 0.5 wt% sodium carboxymethyl cellulose and isobutylene-maleic anhydride copolymer were mixed in a mass ratio of 1:1 to obtain a protective agent solution; salt solutions of catalysts Fe and Co were added to the protective agent solution, and Fe and Co salts were mixed in a molar ratio of 1:1 to prepare a catalyst precursor solution with a total metal concentration of 0.15 wt%.

[0050] (5) The ceramsite green body after staged sintering was placed in a catalyst precursor solution in a vacuum tank. The pressure in the vacuum tank was maintained at 0.08~0.1MPa for 1.5h. After returning to normal pressure, it was allowed to stand for 3h. Then, the hollow silica nanospheres were removed by pickling with 1mol / LHF solution for 30min to obtain modified ceramsite.

[0051] (6) The modified ceramsite was dried at 130°C for 15 h, and then placed in an atmosphere furnace at 400°C for 2 h to obtain oleophilic ceramsite. The atmosphere in the atmosphere furnace was argon.

[0052] Example 3:

[0053] A method for preparing an oleophilic ceramsite material for industrial wastewater treatment comprises the following steps:

[0054] (1) Blast furnace slag, iron tailings powder, waste activated carbon powder and river sand were weighed according to the weight ratio, placed in a double-roller ball mill, fully mixed and ball-milled to 200 mesh, and then magnetically separated to remove metal impurities, and then dried at a temperature of 110°C to obtain a mixed powder; the mass percentage of SiO2 in the iron tailings powder was ≥75%.

[0055] Among them, the weight ratio of blast furnace slag, iron tailings powder, waste activated carbon powder and river sand is: 58 parts of blast furnace slag, 25 parts of iron tailings powder, 18 parts of waste activated carbon powder and 10 parts of river sand.

[0056] (2) Adding hollow silicon dioxide nanospheres to the mixed powder, adding water glass after mixing and mixing thoroughly, then granulating it through a disc granulator and drying it at room temperature for 13 hours to obtain a ceramsite body.

[0057] The mass ratio of the mixed powder to the hollow silica nanospheres is 1:6, and the mass ratio of the mixed powder to water glass is 10:2. The modulus of the water glass is 2, and the particle size of the hollow silica nanospheres is 150-200 nm.

[0058] (3) The prepared ceramsite body is placed in a muffle furnace for staged sintering: pretreatment stage: keep warm at 180 °C for 2 h; high temperature sintering stage: keep warm at 750 °C for 2 h; finally cool to room temperature.

[0059] (4) Sodium carboxymethyl cellulose with a mass fraction of 0.1 wt% and isobutylene-maleic anhydride copolymer were mixed in a mass ratio of 1:1 to obtain a protective agent solution; salt solutions of catalysts Fe and Co were added to the protective agent solution, and Fe and Co salts were mixed in a molar ratio of 1.2:1 to prepare a catalyst precursor solution with a total metal concentration of 0.2 wt%.

[0060] (5) The ceramsite green body after staged sintering was placed in a catalyst precursor solution in a vacuum tank. The pressure in the vacuum tank was maintained at 0.08~0.1MPa for 2h. After returning to normal pressure, it was allowed to stand for 4h. Then, the hollow silica nanospheres were removed by pickling with 1mol / LHF solution for 30min to obtain modified ceramsite.

[0061] (6) The modified ceramsite is pretreated by drying it at 130°C for 15 hours and then subjected to high temperature treatment by placing it in an atmosphere furnace at 400°C for 2 hours to obtain oleophilic ceramsite. The atmosphere in the atmosphere furnace is argon.

[0062] The lipophilic ceramsite obtained in the above three embodiments has its physical and chemical properties tested as shown in the following table:

[0063]

[0064] Based on the above results, the oleophilic ceramsite material obtained by this method exhibits high porosity and low bulk density through microstructural control, while maintaining excellent cylinder compressive strength and exhibiting significant oil wettability. Compared to traditional ceramsite materials, the ceramsite prepared by this method exhibits superior physical properties and surface oil wettability.

[0065] The preferred embodiments of the present invention are described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the scope of the technical concept of the present invention, the technical solution of the present invention can be subjected to a variety of simple modifications, and these simple modifications all fall within the scope of protection of the present invention. It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner unless there is any contradiction. In order to avoid unnecessary repetition, the present invention will no longer describe various possible combinations separately. In addition, the various different embodiments of the present invention can also be arbitrarily combined, and as long as they do not violate the concept of the present invention, they should also be regarded as the contents disclosed by the present invention.

Claims

1. A method for preparing an oleophilic ceramsite material for industrial wastewater treatment, characterized in that: The steps include: (1) Weigh blast furnace slag, iron tailings powder, waste activated carbon powder and river sand according to the weight ratio, place them in a ball mill, fully mix them and ball mill them to 200 mesh, then remove metal impurities by magnetic separation, and then dry them to obtain a mixed powder; The weight ratio of the blast furnace slag, iron tailings powder, waste activated carbon powder and river sand is: 40-60 parts of blast furnace slag, 15-30 parts of iron tailings powder, 10-20 parts of waste activated carbon powder and 5-10 parts of river sand; (2) adding hollow silicon dioxide nanospheres to the mixed powder, adding water glass after mixing and fully mixing, then granulating the mixture through a granulator and drying it at room temperature to obtain a ceramsite body; The mass ratio of the mixed powder to the hollow silica nanospheres is 1:(4-6); the mass ratio of the mixed powder to the water glass is 10:(1.5-2); (3) The prepared ceramsite body is placed in a muffle furnace for staged sintering: pretreatment stage: keep at 150-180 °C for 1-3 hours; high temperature sintering stage: keep at 550-750 °C for 1-3 hours; finally cool to room temperature; (4) Mixing sodium carboxymethyl cellulose with a mass fraction of 0.1-1 wt% and isobutylene-maleic anhydride copolymer in a mass ratio of 1:(1-3) to obtain a protective agent solution; adding a salt solution of catalysts Fe and Co to the protective agent solution to prepare a catalyst precursor solution; wherein the Fe and Co salts are mixed in a molar ratio of (0.8-1.2):1 to prepare a catalyst precursor solution with a total metal concentration of 0.01-0.2 wt%; (5) The sintered ceramsite body is placed in a catalyst precursor solution in a vacuum tank, and the pressure in the vacuum tank is maintained at 0.08-0.1 MPa for 1-2 h. After returning to normal pressure, the body is allowed to stand for 2-4 h. The hollow silica nanospheres are then removed by pickling with a 1 mol / L HF solution for 10-30 min to obtain the modified ceramsite. (6) The modified ceramsite is dried at 110-130°C for 12-15 hours, and then placed in an atmosphere furnace at 250-400°C for 2-3 hours to obtain oleophilic ceramsite.

2. The method for preparing an oleophilic ceramsite material for industrial wastewater treatment according to claim 1, wherein: In the step (1), the ball mill is a double-roller ball mill; and the drying temperature is 90-110°C.

3. The method for preparing an oleophilic ceramsite material for industrial wastewater treatment according to claim 1, wherein: In the step (1), the mass percentage of SiO2 in the iron tailings powder is ≥75%.

4. The method for preparing an oleophilic ceramsite material for industrial wastewater treatment according to claim 1, wherein: In the step (2), the granulator is a disc granulator, and the drying time at room temperature is 12 to 15 hours.

5. The method for preparing an oleophilic ceramsite material for industrial wastewater treatment according to claim 1, wherein: In the step (2), the modulus of the water glass is 1.5-2.

6. The method for preparing an oleophilic ceramsite material for industrial wastewater treatment according to claim 1, wherein: In the step (2), the particle size of the hollow silica nanospheres is 150-200 nm.

7. The method for preparing an oleophilic ceramsite material for industrial wastewater treatment according to claim 1, wherein: In the step (6), the atmosphere in the atmosphere furnace includes argon, nitrogen or argon-hydrogen mixed gas.

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