Technology for reducing waste incineration fly ash via water logging pretreatment

Abstract

The invention relates to a technology for reducing waste incineration fly ash via water logging pretreatment, and the technology is particularly suitable for the treatment of waste incineration fly ash with salt content higher than 20%. A water logging dechlorination manner is used for treating waste incineration fly ash; by prolonging the logging time, the water consumption is greatly reduced, a subsequent wastewater treatment process is simplified at the same time and a soluble salt resource is recycled; before fly ash enters into a furnace, most of heavy metals and chlorine salts are removed, a matrix of fly ash is purified, and by virtue of existing incineration equipment of waste incineration power plants, pollutants such as dioxin are thoroughly degraded, so that the overall normal running of a waste incineration line is ensured and the harmless and reduction treatment of waste incineration fly ash is realized. The technology has a characteristic of correct in-situ treatment, and is simple in process and low in investment and operation costs; by gathering most of heavy metals and salts in heavy metal plaster and gathering little of the two in secondary fly ash, the reduction of waste incineration fly ash is realized, and then a favorable foundation is laid for the subsequent further treatment or resource utilization.

Description

Technical field [0001] The technology relates to a water immersion pretreatment reduction technology for waste incineration fly ash, and belongs to the technical field of hazardous waste treatment and disposal. Background technique [0002] The waste incineration process will produce 3-15% of waste incineration fly ash, which contains high concentrations of heavy metals, dioxin pollutants and a large amount of salt, which causes serious harm to the environment and human health, and is defined as dangerous Waste requires special treatment. At the end of the "Twelfth Five-Year Plan" period, the country plans to build 380 waste incineration power plants, and the annual fly ash output will approach the 4 million tons mark. A large amount of fly ash urgently needs to be properly disposed of. [0003] At present, fly ash treatment methods mainly include solidification method, agent stabilization method, acid precipitation method, melting method and sintering method. High temperature tre...

AI Technical Summary

Problems solved by technology

[0004] However, the common technical defect of the fly ash sintering technology at home and abroad is that the purification and removal of heavy metals has not been realized before the fly ash enters the furnace, resulting in a large amount of volatilization of heavy metals during the high-temperature sintering process, and the cyclic enrichment in the kiln causes skinning or smoke. Secondary hazards are caused by gas discharge, and the implementation of treatment technology requires the construction of a special treatment plant and a complete set of treatment equipment. The construction investment cost is high, the treatment capacity is limited, and the reproducibility is poor.

Li Bingzheng of Chongqing Ruifan Renewable Resources Development Co., Ltd.'s invention patent "Method for Harmless Disposal of Garbage Fly Ash Using Waste Incineration Process" (application number: 201010228621.7) utilizes the existing equipment of the waste incineration plant and reduces the processing cost, but This technology is to add auxiliary materials to the fly ash, and use high-temperature sintering to reduce and solidify the heavy metals in the pellets, thereby reducing the heavy metal leaching rate of the sintered balls, but the heavy metal content is still high, and there are problems when the obtained slag is used as a resource. potential hazard

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