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CN-121972491-A - By adding trace alpha-MnO2Method for realizing low-temperature detoxification of dioxin in fly ash

CN121972491ACN 121972491 ACN121972491 ACN 121972491ACN-121972491-A

Abstract

The invention relates to the technical field of solid waste treatment and environmental protection, in particular to a method for realizing low-temperature degradation of dioxin in fly ash by adding trace alpha-MnO 2 . According to the method, trace manganese-based catalyst and waste incineration fly ash are fully and uniformly mixed, the mixture is put into a heat treatment furnace under an anoxic atmosphere, the problem of difficult contact of solid phase reaction is effectively solved under the condition that a large amount of catalyst is not required to be added by utilizing the high dispersibility and synergistic effect of the trace catalyst in a solid phase matrix, the treatment energy consumption and the material cost are obviously reduced, the operation is simple and convenient, the deep degradation and thorough detoxification of dioxin in the fly ash are realized, the purpose of pollution and carbon reduction is achieved, the secondary pollution is avoided, and solid environmental safety guarantee is provided for the subsequent recycling of the fly ash.

Inventors

  • LI WEISHI
  • Guo zhenhao
  • YAN DAHAI
  • LI LI
  • CUI CHANGHAO
  • CHEN CHAO
  • LIU MEIJIA
  • LI DAN
  • HUANG QIFEI

Assignees

  • 中国环境科学研究院

Dates

Publication Date
20260505
Application Date
20251223

Claims (10)

  1. 1. A method for realizing low-temperature detoxification of dioxin in fly ash by adding trace alpha-MnO 2 , which is characterized by comprising the following steps: the alpha-MnO 2 catalyst is mixed with the fly ash to be treated, and after being fully mixed, the heat treatment is carried out; The addition amount of the alpha-MnO 2 catalyst is 0.1-1.0wt% of the fly ash.
  2. 2. The method of claim 1, wherein the alpha-MnO 2 catalyst is added in an amount of 0.1 to 0.5 wt% of the fly ash mass.
  3. 3. The method of claim 1, wherein the α -MnO 2 catalyst is a nano α -MnO 2 catalyst.
  4. 4. The method of claim 1, wherein the morphology of the α -MnO 2 catalyst is nanorod, nanowire, nanotube, or nanofiber.
  5. 5. The method of claim 4, wherein the morphology of the α -MnO 2 catalyst is nanorod-like.
  6. 6. The method of claim 1, wherein the mixing is by stirring.
  7. 7. The method of claim 1, wherein the heat treatment temperature is 300-400 ℃ and the heat treatment time is 30-120 min.
  8. 8. The method of claim 6, wherein the heat treatment temperature is 400 ℃ and the heat treatment time is 90min.
  9. 9. The method of claim 1, wherein the heat treatment is performed under an inert atmosphere of nitrogen, argon or helium.
  10. 10. The method of claim 1, wherein the total degradation rate of dioxin is 99.0% or more and the total detoxification rate of dioxin is 99.0% or more.

Description

Method for realizing low-temperature detoxification of dioxin in fly ash by adding trace alpha-MnO 2 Technical Field The invention relates to the technical field of solid waste treatment and environmental protection, in particular to a method for realizing low-temperature detoxification of dioxin in fly ash by adding trace alpha-MnO 2. Background The information disclosed in the background of the invention is only for enhancement of understanding of the general background of the invention and is not necessarily to be taken as an admission or any form of suggestion that this information forms the prior art already known to a person of ordinary skill in the art. Dioxin, a colorless, odorless, severely toxic, fat-soluble substance, is a general term for a large class of substances that can bind to aromatic hydrocarbon receptors and cause various biochemical changes. Dioxins are one of the most toxic compounds known, and have centuries of toxicity, teratogenicity, carcinogenicity, mutagenicity, and ability to damage human reproductive system and immune system. The fly ash is used as a key solid phase carrier for enriching the dioxin, the toxicity equivalent of the dioxin is generally higher (300-1000 ng I-TEQ/kg), and the fly ash becomes a remarkable environmental risk source. Therefore, fly ash is a main carrier for discharging dioxin in the garbage incineration process and must be removed. The existing dioxin treatment method mainly comprises a flue gas purification device, activated carbon adsorption, catalytic decomposition, chemical treatment, flue gas quenching, electron beam irradiation and other methods. The fume purifier mainly uses water in wet dust collector to carry away micro flyash particles with adsorbed dioxin carried in fume. The activated carbon adsorption achieves the aim of adsorbing dioxin by utilizing the larger specific surface area of the activated carbon. The catalytic decomposition method mainly utilizes catalysts of iron-manganese series, vanadium-titanium series and the like to degrade dioxin pollutants in industrial flue gas into nontoxic micromolecule emission. The chemical treatment is to spray ammonia gas into the flue gas to control the generation of the precursor or to spray calcium oxide to absorb HCl. The flue gas quenching technology is used for rapidly cooling tail industrial flue gas to 200-300 ℃ so as to avoid a temperature interval generated by dioxin, and therefore, the generation of dioxin is reduced. The electron beam irradiation is to destroy chemical structure of dioxin by using electron beam to generate reactive substances such as active oxygen in the flue gas. In the existing treatment method, catalytic decomposition is paid attention, but the traditional catalytic decomposition method is usually carried out at high temperature, and has the problems of huge energy consumption, serious equipment corrosion, high operation cost and the like, so that the current strategic requirements of pollution reduction and carbon reduction are difficult to meet. In contrast, catalytic decomposition at a low temperature of 300-400 ℃ has remarkable advantages in terms of energy consumption and cost reduction, and has a good industrialized prospect, but how to realize efficient degradation and detoxification of dioxin under such mild low-temperature conditions is always a technical problem to be overcome in the field. The current low-temperature catalytic degradation research is mainly focused on dioxin treatment in a gas-phase environment, and serious defects are paid attention to solid-phase fly ash matrixes with complex components (containing heavy metals, chloride salts, unburned carbon and the like). In solid phase systems, contaminants adhere to the surfaces of the fly ash particles, and how to ensure effective physical contact and chemical reaction between the applied catalyst and the solid phase contaminants. In the field of solid-phase catalytic treatment, it is generally considered that a certain catalyst addition amount (for example, 1 wt% or more) is required to be maintained in order to ensure that the catalyst has sufficient distribution density and contact probability in a huge solid-phase matrix in order to overcome the problems of difficult contact between solid-phase particles and low mass transfer efficiency. However, there is currently no systematic study of the dispersion behavior of the catalyst in complex fly ash matrices and its specific effect on dioxin degradation at trace amounts (e.g., on the order of 0.1 wt%). The prior art does not reveal a special relation possibly existing between the catalyst dosage and the degradation efficiency in a specific low-temperature solid-phase reaction system, namely, the micro catalyst has higher dispersity and stronger synergistic effect with a matrix, and the catalytic effect of the micro catalyst is possibly superior to that of the micro catalyst when the micro catalyst is added in a higher amount (such as more than 1