A method for preparing activated carbon porous adsorbing material by using waste rolling oil diatomite

Abstract

The present application belongs to the technical field of solid waste resource utilization, and provides a method for preparing activated carbon porous adsorption material from waste rolling oil diatomite, comprising: drying the oil-containing waste diatomite, then carbonizing the dried oil-containing waste diatomite at 200-800 DEG C in vacuum or inert atmosphere to obtain a composite powder; sintering the composite powder at 900-1200 DEG C in vacuum or inert atmosphere to obtain diatomite-based activated carbon porous adsorption material. The present application realizes the resource utilization of waste oil-containing diatomite in the aluminum industry, successfully converts a hazardous waste into a composite porous adsorption material that can be used to protect the ecological environment; the present application is simple, safe, green and pollution-free, and realizes the complete utilization of raw materials, solving the shortcomings of existing waste oil-containing diatomite disposal and utilization technology; the prepared composite porous adsorption material has a micrometer-level porous structure, a large specific surface area and can be reused, and under the premise of modification, has multiple potential application directions.

Description

Technical Field

[0001] This invention belongs to the field of solid waste resource utilization technology, and in particular relates to a method for preparing activated carbon porous adsorption materials using high-oil-content waste diatomite from the aluminum industry. Background Technology

[0002] The statements herein provide only background information in relation to this invention and do not necessarily constitute prior art.

[0003] Diatomaceous earth is a mineral with stable chemical properties, high porosity, large specific surface area, and strong adsorption capacity. Its main component is amorphous silicon dioxide. It is commonly used as a filter aid in the aluminum processing industry. Waste diatomaceous earth used for filtration contains about 30% oil and is classified as hazardous waste (hazardous waste code 900-213-08).

[0004] Currently, methods for disposing of oily diatomaceous earth include distillation, acid washing, oil-water azeotropic distillation, and steam flushing. All these methods aim to remove and extract the oil. However, even after these processes, the waste diatomaceous earth still contains residual rolling oil. Waste diatomaceous earth treated by distillation or acid washing still contains 2% or more oil, while waste diatomaceous earth treated by oil-water azeotropic distillation or steam flushing contains well over 10% residual rolling oil. All treated waste diatomaceous earth remains hazardous waste. Furthermore, distillation is a complex process with fire and explosion hazards; acid washing uses hazardous chemicals such as sulfuric acid, posing significant operational risks; and oil-water azeotropic distillation and steam flushing methods consume large amounts of water and have high energy consumption.

[0005] Patent CN110918062A discloses a method for preparing a mesoporous SiO2@C composite material that uses waste oil as a carbon source to adsorb and eliminate toluene in the air. However, the method of preparing the mesoporous SiO2@C composite material by directly mixing and carbonizing waste oil and mesoporous SiO2 still needs to be improved in terms of the loading and uniformity of activated carbon. Summary of the Invention

[0006] To address the shortcomings of existing technologies for utilizing and disposing of waste diatomaceous earth from aluminum rolling oil, this invention provides a method for preparing diatomaceous earth-based activated carbon porous composite materials in situ using oil-containing waste diatomaceous earth. This invention uses waste rolling oil diatomaceous earth to prepare activated carbon porous adsorbent materials through staged carbonization, effectively improving the loading capacity and mechanical strength of the activated carbon porous adsorbent materials.

[0007] To achieve the above objectives, the present invention adopts the following technical solution:

[0008] In a first aspect, the present invention provides a method for preparing activated carbon porous adsorbent materials using waste rolling oil diatomaceous earth, comprising:

[0009] After drying the oily waste diatomaceous earth, the dried oily waste diatomaceous earth is carbonized in stages at 200-800℃ under vacuum or inert atmosphere to obtain composite powder.

[0010] The composite powder is sintered at 900-1200℃ under vacuum or inert atmosphere to obtain diatomaceous earth-based activated carbon porous adsorption material.

[0011] This invention provides a technology for the in-situ resource utilization of oil-containing diatomite, and the resulting product can be used as an adsorbent material in wastewater treatment and other fields.

[0012] In a second aspect, the present invention provides an activated carbon porous adsorption material prepared by the above-described method.

[0013] A third aspect of the present invention provides applications of the above-mentioned activated carbon porous adsorbent material in the fields of environmental protection, food, medicine, chemical industry, power, aerospace and defense.

[0014] Beneficial effects of the present invention

[0015] (1) This invention realizes the resource utilization of waste oily diatomite in the aluminum industry and successfully transforms a hazardous waste into a composite porous adsorption material that can be used to protect the ecological environment.

[0016] (2) The process of this invention is simple, safe, green and pollution-free, and it achieves complete utilization of raw materials, solving the shortcomings of existing waste oily diatomite disposal and utilization technologies.

[0017] (3) The composite porous adsorbent material prepared by the present invention has a micron-scale porous structure, a large specific surface area, and can be reused. With the premise of modification, it has multiple potential application directions.

[0018] (4) Compared with patent CN110918062A, the diatomite of the present invention is itself a silicon-based porous adsorption material. The present invention utilizes waste diatomite that has adsorbed waste rolling oil to prepare diatomite-based activated carbon porous composite material in situ, realizing the in-situ resource utilization and productization of hazardous waste. The main raw materials for production all come from the hazardous waste itself, which has better economic and environmental benefits.

[0019] Meanwhile, since the composition of rolling oil is relatively complex, the carbon chain length is mostly concentrated between C9 and C16. Different carbon chain lengths determine that the distillation temperature of different components in waste rolling oil is different (which can be understood as volatilization temperature). Staged carbonization can carbonize as many components as possible in waste rolling oil, increase the activated carbon loading of the activated carbon porous adsorption material, and reduce the oil content in the exhaust gas, thus reducing the pressure of subsequent exhaust gas treatment.

[0020] Finally, since the diatomaceous earth has been fully wetted by rolling oil during the upstream aluminum industry processing, the rolling oil is in a saturated / basically saturated state on the surface and in the internal pores of the diatomaceous earth. Therefore, the activated carbon loading of the activated carbon adsorbent material obtained by this invention is higher and more uniform. Attached Figure Description

[0021] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. Exemplary embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0022] Figure 1 Surface morphology of diatomite-based activated carbon porous composite material.

[0023] Figure 2 Image of a diatomaceous earth-based activated carbon porous composite material sample (5cm×5cm×10cm). Detailed Implementation

[0024] It should be noted that the following detailed descriptions are exemplary and intended to provide further illustration of the invention. Unless otherwise specified, all technical and scientific terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0025] A method for preparing activated carbon porous adsorbent materials using waste rolling oil diatomaceous earth includes:

[0026] After drying the oily waste diatomaceous earth, the dried oily waste diatomaceous earth is carbonized in stages at 200-800℃ under vacuum or inert atmosphere to obtain composite powder.

[0027] The composite powder is sintered at 900-1200℃ under vacuum or inert atmosphere to obtain diatomaceous earth-based activated carbon porous adsorption material.

[0028] In some embodiments, the oil content in the oily waste diatomaceous earth is 2%-40% by mass.

[0029] In some embodiments, the oil contains light components C9-C 11 The proportion of intermediate component C is 0%-50%. 12 -C 14 30%-100% of the total, recombinant component C 15 The proportion of those above 0%-50%

[0030] In some embodiments, the carbonization temperature of the light component rolling oil is 200-300°C.

[0031] In some embodiments, the intermediate component rolling oil carbonization temperature is 300-500°C.

[0032] In some embodiments, the carbonization temperature of the heavy component rolling oil is 500-800°C.

[0033] In some embodiments, the drying conditions are drying at 100-140°C for 2-8 hours.

[0034] In some embodiments, the inert atmosphere is nitrogen or carbon dioxide.

[0035] The present invention will be further described in detail below with reference to specific embodiments. It should be noted that the specific embodiments are explanations of the present invention and not limitations thereof.

[0036] In the following embodiments, the carbon component gasification loss rate and tensile strength were determined after multiple parallel experimental measurements; the loading amount is represented by the carbon component gasification loss rate.

[0037] Example 1

[0038] Waste diatomaceous earth adsorbed rolling oil contains no heavy components: oil content 35%, light components (C9-C) 11 ) accounted for 12%, and intermediate components (C) 12 -C 14 ) accounted for 88%, and the recombinant component (C) 15 (and above) accounted for 0%.

[0039] 1) Weigh 150g of the above-mentioned waste diatomaceous earth and dry it in an oven at 120℃ for 6 hours;

[0040] 2) The material obtained in step 1) is placed in a corundum crucible and then placed in a tube furnace. Under nitrogen protection, it is kept at 280℃ for 2 hours, then heated to 450℃ and kept at 4 hours to complete the carbonization process. The carbonization rate of the waste rolling oil carbon components reaches more than 70%.

[0041] 3) The material obtained in step 2) is heated to 1050℃, the atmosphere is switched to CO2, the flow rate is 160ml / min, and the temperature is maintained for 30min to obtain a high-strength diatomite-based activated carbon porous composite material. The carbon component gasification loss during the preparation process is less than 45%, and the tensile strength of the composite material reaches 3.2-3.8MPa.

[0042] Example 2

[0043] Waste diatomaceous earth adsorbed rolling oil contains no light components: oil content 30%, light components (C9-C) 11 ) accounted for 0%, intermediate component (C) 12 -C 14 ) accounted for 85%, and the recombinant component (C) 15 (and above) accounted for 15%.

[0044] 1) Weigh 150g of the above-mentioned waste diatomaceous earth and dry it in an oven at 140℃ for 4 hours;

[0045] 2) The material obtained in step 1) is placed in a corundum crucible and then placed in a tube furnace. Under nitrogen protection, it is kept at 450℃ for 4 hours, then heated to 700℃ and kept at 700℃ for 3 hours to complete the carbonization process. The carbonization rate of the waste rolling oil carbon components reaches more than 75%.

[0046] 3) The material obtained in step 2) is further heated to 1050℃, the atmosphere is switched to CO2, the flow rate is 160ml / min, and the temperature is maintained for 30min to obtain a high-strength diatomaceous earth-based activated carbon porous composite material (sample attached). Figure 1 , 2 The carbon component gasification loss during the preparation process is less than 40%, and the tensile strength of the composite material reaches 3.2-3.8 MPa.

[0047] Example 3

[0048] High-oil-content waste diatomaceous earth: containing 35% rolling oil by mass, light components (C9-C) 11 ) accounted for 16%, and intermediate components (C) 12 -C 14 ) accounted for 72%, and the recombinant component (C) 15 (and above) accounted for 12%.

[0049] 1) Weigh 150g of the above-mentioned waste diatomaceous earth and dry it in an oven at 120℃ for 6 hours;

[0050] 2) The material obtained in step 1) is placed in a corundum crucible and then placed in a tube furnace. Under nitrogen protection, the temperature is maintained at 280℃ for 2 hours, then raised to 450℃ and maintained for 4 hours, and then raised to 700℃ and maintained for 3 hours to complete the carbonization process. The carbonization rate of the waste rolling oil carbon components reaches more than 78%.

[0051] 3) The material obtained in step 2) is heated to 1050℃, the atmosphere is switched to CO2, the flow rate is 160ml / min, and the temperature is maintained for 30min to obtain a high-strength diatomite-based activated carbon porous composite material. The carbon component gasification loss during the preparation process is less than 40%, and the tensile strength of the composite material reaches 3.2-3.8MPa.

[0052] Example 4

[0053] Low-oil-content waste diatomaceous earth: containing 8% rolling oil by mass, light components (C9-C) 11 ) accounted for 6%, intermediate components (C) 12 -C 14 ) accounted for 84%, and the recombinant component (C) 15 (and above) account for 10%.

[0054] 1) Weigh 150g of the above-mentioned waste diatomaceous earth and dry it in an oven at 110℃ for 6 hours;

[0055] 2) The material obtained in step 1) is placed in a corundum crucible and then placed in a tube furnace. Under nitrogen protection, it is kept at 280℃ for 1 hour, then heated to 450℃ for 2 hours, and then heated to 700℃ for 1 hour to complete the carbonization process. The carbonization rate of the waste rolling oil carbon components reaches more than 78%.

[0056] 3) The material obtained in step 2) is heated to 1050℃, the atmosphere is switched to CO2, the flow rate is 100ml / min, and the temperature is maintained for 20min to obtain a high-strength diatomite-based activated carbon porous composite material. The carbon component gasification loss during the preparation process is less than 40%, and the tensile strength of the composite material reaches 3.2-3.8MPa.

[0057] Example 5

[0058] Oleophilic and hydrophobic modification of porous composite materials based on diatomite activated carbon.

[0059] 1) Prepare 100g of diatomaceous earth-based activated carbon porous composite material according to the method in Example 3 above, and place it in a 250ml beaker;

[0060] 2) Add 100 mg / L polydimethylsiloxane solution to a beaker to cover the diatomaceous earth-based activated carbon porous composite material, and vibrate magnetically for 40 minutes to complete the modification of the composite material.

[0061] 3) The modified composite material was rinsed with anhydrous ethanol and deionized water in sequence;

[0062] 4) After drying the sample, an oleophilic and hydrophobic diatomite-based activated carbon porous composite material was obtained.

[0063] As can be seen from the descriptions in Examples 1-4, the activated carbon porous adsorbent material prepared by graded carbonization of waste rolled oil diatomite has better loading capacity and mechanical strength.

[0064] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for preparing activated carbon porous adsorbent materials by graded carbonization of waste rolling oil diatomaceous earth, characterized in that, include: After drying the oily waste diatomaceous earth, the dried oily waste diatomaceous earth is carbonized in stages at 200-800℃ under a nitrogen atmosphere to obtain composite powder. The composite powder was sintered at 900-1200℃ under a carbon dioxide atmosphere to obtain a diatomaceous earth-based activated carbon porous adsorption material. The oil content in oily waste diatomaceous earth ranges from 8% to 40% by mass. The oil contains light components C9-C 11 0%-50%, intermediate component C 12 -C 14 30%-100% of the total, recombinant component C 15 The proportion of 0% and above is 50%; The carbonization temperature of rolling oil for light components is 200-300℃; The carbonization temperature of the intermediate component rolling oil is 300-500℃; The carbonization temperature of the rolling oil for heavy components is 500-800℃; Different carbon chain lengths determine the different distillation temperatures of different components in waste rolling oil. Staged carbonization allows as many components in waste rolling oil as possible to be carbonized, increasing the activated carbon loading of the prepared activated carbon porous adsorption material, while reducing the oil content in the exhaust gas and alleviating the pressure of subsequent exhaust gas treatment. The tensile strength of the prepared adsorbent material reached 3.2-3.8 MPa.

2. The method for preparing activated carbon porous adsorbent materials by graded carbonization of waste rolling oil diatomaceous earth as described in claim 1, characterized in that, The drying conditions are as follows: drying at 100-140℃ for 2-8 hours.

3. The activated carbon porous adsorbent material prepared by the method according to any one of claims 1-2.

4. The application of the activated carbon porous adsorption material according to claim 3 in the fields of environmental protection, food, medicine and chemical industry.

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