Cooperatively preprocessing method of solid waste incineration flying ash cement kiln of returned effluent

Abstract

The invention discloses a cooperatively preprocessing method of a solid waste incineration flying ash cement kiln of a returned effluent in the technical field of solid waste treatment and disposition. The method comprises four stages of flying ash washing and dechlorinating, washings processing, washed ash dehydrating and calcining in the kiln, wherein, at the stage of flying ash washing and dechlorinating, heavy metals washed out in the washing process are chelated, flocculated and settled, then is filtered and pressed together with the washed ash, and then is put into the kiln. Neutralization and heavy metal sedimentation are carried out on an eluate so that the washings can be discharged after reaching standards. When used for processing flying ash, the method not only can save the raw materials in the cement industry, but also can effectively fixing heavy metals, completely burn dioxin, safely, economically and fast dispose flying ash and greatly improve the environmental, economic and social benefits. With the method, occupied area, water and investment are saved, the operation is reliable, the washed ash and the washings are processed with stable effect, and no secondary pollutant is caused.

Description

technical field [0001] The invention belongs to the technical field of solid waste treatment and disposal, and in particular relates to a method for synergistic pretreatment of household waste incineration fly ash and cement kiln with refluxing eluate. Background technique [0002] In recent years, with the rapid development of waste incineration in our country, as an inevitable product of waste incineration, the output of fly ash is also increasing year by year. At the end of 2008, the incineration and treatment capacity of municipal solid waste in my country was 68540t / d, of which the incineration capacity of grate furnace and fluidized bed was 43970t / d and 24570t / d respectively, and the amount of fly ash produced by grate furnace was 1 / 2 of the amount of waste entering the furnace. 3-5%, the output of fluidized bed fly ash is 15-20% of the furnace waste, then the daily output of fly ash is 5004.6-7112.5t, and the annual output is 1.65-2.35 million tons. Domestic waste inc...

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Problems solved by technology

Our previously submitted invention "method for recycling domestic waste incineration fly ash in cement kiln" (application number 200710177811.9) provides a method for recycling domestic waste incineration fly ash in cement kiln, including water washing-carbonation pretreatment and There are two stages of calcination in the cement kiln. In view of the high pH in the washing liquid and the characteristics that the dissolution of heavy metals is difficult to meet the standard, the patent uses CO 2 Neutralize alkalinity and precipitate heavy metals, but in practical applications, the use of kiln tail gas has a large amount of construction work and high investment, and it is difficult to control the pH in actual operation, and the heavy metal precipitation effect is unstable

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