High-concentration wet filling mold bag treatment method and system for municipal solid waste incineration fly ash

Abstract

The invention discloses a high-concentration wet filling mold bag treatment method for municipal solid waste incineration fly ash. Fly ash homogenization, heavy metal stabilization, dioxin detoxication, rapid hydration consolidation and landfill integration treatment are achieved through the three links of fly ash thick paste or cream preparing, high-pressure pumping or filling and mold bag water segregation or hydration consolidation, no dust pollution or wastewater discharge or ammonia smell dissipation is generated in the treatment process, discharge of fly ash landfill leachate can be greatly reduced, and meanwhile municipal and industrial sludge, silt, river sediment and the like can be collaboratively treated; the consolidated fly ash in a mold bag meets the relevant national standard requirements, and landfill treatment can be conducted on the consolidated mold bag. The invention further discloses a high-concentration wet filling mold bag treatment system for the municipal solid waste incineration fly ash. Accordingly, the defects in large-scale industrial application of traditional dry landfill for the fly ash and a low-concentration slurry filling mold bag treatment method for the fly ash can be avoided, environment-friendly, economic and safe fly ash treatment is achieved, solid waste such as sludge is collaboratively and safely treated, and the method and system can be applied to large-scale industrial production.

Description

technical field [0001] The invention belongs to the technical field of solid waste treatment and disposal, and in particular relates to a method and system for treating domestic waste incineration fly ash with high-concentration wet injection mold bag. Background technique [0002] Domestic waste incineration fly ash is a kind of off-white or dark gray fine powder, with low moisture content, generally rod-shaped, polygonal, cotton-like, spherical and other irregular shapes, uneven particle size, high porosity and large specific surface area specialty. Fly ash is rich in high concentration of chlorine salts, high content of heavy metals and dioxins that are easily leached, and is listed as hazardous waste by countries all over the world (China, code HW18). Therefore, fly ash must undergo strict disposal before landfill and resource utilization. In recent years, research on various fly ash disposal technologies has been carried out at home and abroad, including solidificatio...

AI Technical Summary

Problems solved by technology

The dry landfill disposal of fly ash has the following problems: (1) The composition of fly ash fluctuates greatly, dry mixing cannot achieve a better homogenization effect, the effect of chelating agent cannot be effectively exerted, the dosage is not easy to control stably, and the detoxification effect is unstable ; or in order to ensure the chelating effect, adding excessive chelating agent will increase the cost of the medicament; (2) fly ash contains a large amount of fine dust, which can easily form PM 2.5 pollution sources when exposed to the environment. Although the conventional dry landfill treatment has water spray Humidification, mechanical rolling, preforming and other dust suppression measures, but still can not avoid the impact on the surrounding environment of the landfill; (3) The new ash landfill is often accompanied by a pungent ammonia smell, which can easily cause dissatisfaction among nearby residents. Even lead to mass incidents; (4) Due to the strength of the stabilized fly ash, from the perspective of safety, most of the fly ash landfill only uses the space below the ground and is disposed of in pits, resulting in low utilization of storage capacity; but Some fly ash landfills are piled high on the ground at the same time, in order to use the space above the ground to increase storage capacity, but this brings about poor stability of the pile, safety hazards such as landslides, and environmental problems such as dust pollution; (5) Summer and autumn rainy seasons, no matter Landfill in the pit or piled up on the ground will inevitably form mud, making the landfill operation impossible; (6) There will inevitably be problems with the treatment of landfill leachate, which will increase additional treatment costs

[0006] Since municipal sludge and tailings are general solid wastes, while domestic waste incineration fly ash is hazardous waste (China, code HW18), if the above technology is simply transplanted to the field of disposal of domestic waste incineration fly ash, it will The following problems arise: (1) Environmental protection issues: the products after hazardous waste disposal and the waste residue and waste water generated during the disposal process have strict standard requirements, which are strictly different from general solid waste such as sludge and tailings; (2 ) Technical issues: 1) Sludge and tailings contain 50-95% water, which are water-containing materials. They are treated with mold bags, and only need to consider the problem of dehydration and capacity reduction; while fly ash contains 1-2% water, which belongs to dry materials, and mold bags are used. Pulping and dehydration treatment must be considered at the same time, and the pulping process has a greater impact on the subsequent dehydration effect, and it is required to complete the harmless disposal of fly ash as hazardous waste during the entire treatment process; 2) Sludge And the solid phase concentration of the tailings is generally not more than 50%, and a large amount of wastewater will be generated during the treatment process, but it is usually treated according to the treatment standards of general solid waste; if the fly ash treatment is simply the idea of ​​transplanting sludge and tailings treatment, A large amount of waste water will be produced that needs to be treated in accordance with the requirements of hazardous waste disposal, and the treatment cost is high, which affects the economy of large-scale industrial application of this technology; 3) The mold bags used for solid waste treatment such as sludge or tailings are vulnerable to rainwater penetration, Affect the strength of sludge or tailings consolidation in the mold bag

[0007] Due to the above-mentioned defects and deficiencies in the application of traditional dry landfill of fly ash, and the simple transplantation of mold bags to the field of domestic waste incineration fly ash disposal will lead to problems in technology and environmental protection

Images