A method and system for treating domestic waste incineration fly ash with high concentration wet injection mold bag

Abstract

The invention discloses a high-concentration wet injection mold bag treatment method for domestic waste incineration fly ash, which consists of three steps: fly ash thick slurry / paste preparation, high-pressure pumping / infusion, and mold bag bleeding / hydration consolidation. Realize fly ash homogenization, heavy metal stabilization, dioxin detoxification, rapid hydration consolidation, landfill integrated treatment, no dust pollution, no waste water discharge, no ammonia odor emission during the treatment process, and can greatly reduce fly ash landfill At the same time, it can co-dispose municipal and industrial sludge, silt and river bottom mud, etc.; the fly ash in the mold bag after consolidation meets the requirements of relevant national standards, and the consolidated mold bag body can be landfilled disposal. The invention also discloses a high-concentration wet-process perfusion mold bag treatment system for domestic garbage incineration fly ash. The invention can avoid the deficiencies in the large-scale industrial application of the traditional dry landfill of fly ash and the low-concentration slurry filling mold bag treatment method of fly ash, realize the environmental protection, economical and safe fly ash disposal, and simultaneously cooperate with the safe disposal of pollution. Solid waste such as mud 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 a system for treating a high-concentration wet infusion mold bag of domestic waste incineration fly ash. Background technique [0002] Domestic waste incineration fly ash is a kind of gray-white or dark gray fine powder with low moisture content, generally rod-shaped, horny, cotton-wool, spherical and other irregular shapes, uneven particle size, high porosity and large specific surface area. specialty. Fly ash is rich in high concentrations of chloride salts, high levels of easily leached heavy metals and dioxins, and is classified as hazardous waste by countries around the world (China, code HW18). Therefore, fly ash must be strictly disposed before landfill and resource utilization. In recent years, a variety of fly ash disposal technologies have been studied at home and abroad, including solidification stabilization, separ...

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 agent; (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 spraying Humidification, mechanical rolling, preforming and other dust suppression measures, but still cannot avoid the impact on the surrounding environment of the landfill; (3) Due to the strength of the stabilized fly ash, from the perspective of safety, most of the fly ash filling The burial only uses the space below the ground and is disposed of in the pit, resulting in a low utilization rate of the storage capacity; however, some fly ash landfills are also piled high on the ground in order to use the space above the ground to increase the storage capacity, but it brings Poor stability, safety hazards such as landslides, and environmental problems such as dust pollution; (4) During the summer and autumn rainy seasons, no matter whether the pit is filled or the ground is piled up, mud will inevitably form, making the landfill operation impossible; (5) There is inevitably a landfill The problem of leachate treatment increases additional treatment costs

[0006] Since municipal sludge and mine tailings are general solid wastes, while MSW incineration fly ash is hazardous waste (China, code HW18), if the above technology is simply transplanted to the disposal field of MSW 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 transplanted sludge and tailings treatment ideas, A large amount of wastewater that needs to be treated according to the requirements of hazardous waste disposal will be generated, and the treatment cost is high, which will affect the economics 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

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