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CN-122010529-A - Method for preparing high-performance porous ceramic material by high-value low-carbon recycling of oil-containing solid waste pyrolysis ash

CN122010529ACN 122010529 ACN122010529 ACN 122010529ACN-122010529-A

Abstract

The invention belongs to the fields of recycling utilization of oil-containing solid waste and preparation of ceramic materials, and discloses a method for preparing a high-performance porous ceramic material by recycling high-value low-carbon pyrolysis ash of oil-containing solid waste, which comprises the following steps of S1, ash pretreatment, magnetic separation impurity removal, particle size classification and activation modification treatment of the pyrolysis ash of the oil-containing solid waste; S2, proportioning and molding, mixing the pretreated ash slag, kaolin, pore-forming agent and sintering aid according to a gradient proportion, preparing a porous biscuit by adopting a dry pressing molding process, S3, optimizing the sintering process, forming a porous ceramic matrix with a gradient pore channel structure by a staged temperature control sintering strategy, and S4, performing performance enhancement, and performing surface modification treatment on the porous matrix by adopting a sol dipping method. According to the invention, through component reconstruction and structure regulation of pyrolysis ash, the porous ceramic material with high porosity and excellent mechanical strength is prepared, the adsorption capacity is improved by more than 40% compared with that of the traditional product, and the high-value utilization of hazardous waste resources and the effective combination of a low-carbon preparation technology are realized.

Inventors

  • XIA SHIBIN
  • REN JING
  • WU ZHONGKUI
  • DAI HONGCHENG
  • ZHANG TIANLONG
  • ZHANG TIANHU

Assignees

  • 武汉理工大学
  • 十堰卓奇环保科技有限公司

Dates

Publication Date
20260512
Application Date
20260115

Claims (10)

  1. 1. The method for preparing the high-performance porous ceramic material by recycling the high-value low-carbon pyrolysis ash of the oil-containing solid waste is characterized by comprising the following steps of: S1, ash pretreatment, namely, carrying out treatment on oily solid waste to obtain pyrolysis ash, removing metal impurities from the pyrolysis ash, coarsely crushing the pyrolysis ash, and then finely grinding the pyrolysis ash; S2, batching and forming, namely mixing the pretreated ash, kaolin, pore-forming agent and sintering aid in proportion, dry-mixing, spraying polyvinyl alcohol solution, granulating, and carrying out compression molding on the mixture to prepare a biscuit; S3, optimizing a sintering process, namely heating the biscuit to remove a pore-forming agent, then heating the biscuit to form a skeleton structure, then heating the biscuit to realize mullite crystal phase growth, and finally cooling the biscuit in air after gradient cooling to obtain a porous ceramic matrix with gradient pore channels; S4, performance enhancement, namely immersing a matrix into SiO 2 -Al 2 O 3 composite sol, performing vacuum-assisted permeation, performing secondary sintering to form a nano-modification layer, then spraying a TiO 2 photocatalytic coating, drying and curing to obtain the high-performance porous ceramic material.
  2. 2. The method of claim 1, wherein in the step S1, the mass ratio of SiO 2 /Al 2 O 3 of the pretreated ash is 1.2-2.5, the total heavy metal content is less than or equal to 3wt%, the raw materials are crushed to be less than 5mm, the raw materials are finely ground to D50=20-50 μm, and the surface activation condition is that stirring is carried out for 30min at 60 ℃.
  3. 3. The method according to claim 1, wherein the CaO content of the ashes after pickling in the step S1 is 1.5 wt.% or less.
  4. 4. The method according to claim 1, wherein in the step S2, the pretreated ash, kaolin, pore-forming agent and sintering aid are (60-75 wt%, (15-25 wt%, (10-15 wt%), and (3-5 wt%), the pore-forming agent is starch, the sintering aid is borax, the grain size of the starch is 80-150 μm, and the borax addition amount is preferably 4wt%.
  5. 5. The method according to claim 1, wherein in the step S3, the pore-forming agent is removed by heating to 600 ℃ at 5 ℃ per minute and preserving heat for 1h, a framework structure is formed by heating to 1100 ℃ at 3 ℃ per minute on the basis of 600 ℃, then mullite crystal phase growth is realized by heating to 1350 ℃ at 2 ℃ per minute on the basis of 1100 ℃ and preserving heat for 2h, and finally cooling is carried out by cooling to 800 ℃ from 1350 ℃ at 5 ℃ per minute in a gradient mode and then air cooling is carried out, wherein the total cooling time is more than or equal to 4h.
  6. 6. The method according to claim 5, wherein in the step S3, the heat preservation time of the high temperature crystallization stage is positively correlated with the ash mixing amount, and the heat preservation time is prolonged to 2.5 hours when the ash content is more than or equal to 70 wt%.
  7. 7. The method according to claim 1, wherein in the step S4, the SiO 2 -Al 2 O 3 composite sol has an Al/Si molar ratio of 0.3 to 0.6.
  8. 8. The method according to claim 1, wherein in the step S4, the vacuum assisted infiltration is performed for 30min, and the secondary sintering is performed under the condition that the temperature is raised to 1250 ℃ at a temperature raising rate of 10 ℃ per min, and the temperature is kept for 1h, so as to form the nano-modification layer.
  9. 9. The method according to claim 1, wherein in the step S4, the TiO 2 photocatalytic coating is sprayed by a sol-gel method, the spraying thickness is 150-250nm, the bonding strength of the coating and the substrate after curing is not less than 15MPa, and the photocatalytic efficiency of the TiO 2 coating is not less than 80%.
  10. 10. The method according to claim 1, wherein in the step S4, the vacuum degree of sol impregnation is-0.08 to-0.1 MPa, and the weight gain of the impregnated blank is 8-12%.

Description

Method for preparing high-performance porous ceramic material by high-value low-carbon recycling of oil-containing solid waste pyrolysis ash Technical Field The invention relates to the technical field of recycling utilization of oil-containing solid wastes and preparation of functional ceramic materials, in particular to a method for preparing a high-performance porous ceramic material by recycling high-value low-carbon pyrolysis ash of the oil-containing solid wastes, which is used for preparing the high-performance porous ceramic material by reconstructing pyrolysis ash components and regulating and controlling the structure, so as to realize harmless, high-value and low-carbonization cooperative treatment of the oil-containing solid wastes. Background After pyrolysis treatment, the oily solid waste (such as oil sludge, oil-based drilling cuttings and the like) still contains heavy metals, residual hydrocarbons and inorganic mineral components (such as SiO 2、Al2O3, caO and the like), and the solid waste is directly buried to cause pollution of soil and underground water, so that the incineration treatment is at risk of dioxin generation. The existing recycling technology is mostly focused on building material blending of ash residues (such as brick making and roadbed materials) or cement kiln CO-treatment, but has the problems of low added value (product price is less than 500 yuan/ton), hidden danger of heavy metal leaching, high carbon emission intensity (CO 2/ton product) and the like. The porous ceramic material has remarkable requirements in the fields of industrial adsorption, catalytic carriers and the like due to the characteristics of high specific surface area, corrosion resistance and designable pore structure, but the traditional raw materials (such as kaolin and silicon carbide) depend on mineral exploitation and the sintering energy consumption is high (more than or equal to 1500 ℃). Researches show that SiO 2/Al2O3 mass ratio (1.2-2.5) in the oil-containing solid waste pyrolysis ash has good suitability with a porous ceramic matrix, but residual oil (0.5-3 wt%) and heavy metals (such as Cr and Ni) can damage ceramic sintering compactness, so that porosity fluctuation (40-60%) and compressive strength are insufficient (< 15 MPa). In the prior art, patent CN113003970A proposes that ' preparing haydite from oil sludge ash, but the porosity of the product is only 45-50%, and the problem of heavy metal sealing is not solved, and the literature ' preparation of porous materials based on hazardous waste ash ' adopts an acid washing-high temperature melting method, so that the Pb solidification rate is improved to 90%, but the energy consumption is increased by 30%. In addition, CO 2 generated by decomposition of pore formers (e.g., carbonates) in the conventional process is directly discharged, contrary to the low carbon goal. Disclosure of Invention In order to solve the problems in the prior art, the invention aims to provide a method for preparing a high-performance porous ceramic material by recycling high-value low-carbon pyrolysis ash residues of oil-containing solid waste heat, and the prepared porous ceramic material The method has the characteristics of high slag mixing amount (60-75%), controllable pore structure (porosity is more than 65%), environmental safety (heavy metal leaching concentration is less than 1 mg/L) and low-temperature sintering (at a temperature of less than or equal to 1350 ℃), and can promote the hazardous waste treatment to the upgrading and transformation of functional material manufacture. In order to achieve the aim, the invention provides a method for preparing a high-performance porous ceramic material by recycling high-value low-carbon pyrolysis ash of oil-containing solid waste heat, which comprises the following steps: S1, ash pretreatment, namely carrying out heat preservation on oily solid waste at 550 ℃ for 2 hours in an air atmosphere to obtain pyrolysis ash, removing metal impurities (the iron content is less than or equal to 0.5%) from the pyrolysis ash through a permanent magnet roller separator, coarsely crushing the pyrolysis ash to be less than 5mm through a jaw crusher, finely grinding the pyrolysis ash through a ball mill until D50=20-50 mu m, mixing the ground ash with a silane coupling agent with the mass fraction of 3%, stirring the mixture for 30 minutes at 60 ℃ to perform surface activation, and finally soaking the mixture for 2 hours by adopting dilute hydrochloric acid with the mass fraction of 5% to remove residual oil and calcium and magnesium impurities (the oil content residual quantity is less than 0.3%), and drying the mixture to obtain pretreated ash; in the step S1, the particle size and uniformity of the ash can be adjusted by preprocessing the ash, so that the subsequent forming is convenient. S2, batching and forming, namely mixing the pretreated ash (60-75wt%), the kaolin (15-25wt%), the starch pore-forming agent (10-15wt%) a