Household waste incineration fly ash cyclic utilization method

Abstract

The invention relates to a household waste incineration fly ash cyclic utilization method. A flow distributing device is installed at the lower end of a dust remover of a waste incineration smoke treatment system and controls the amount of fly ash circularly entering a non-medium grinding machine, and therefore the phenomenon that since the fly ash agglomerates at a grinding medium or adheres to the inner wall of the grinding machine, the grinding effect is influenced is avoided. After the fly ash is smashed in a grinding bin, a high-pressure centrifugal fan brings the grinded powder materialsinto a powder selecting machine, fine powder meeting the fineness requirement enters a circulatory system along with airflow, and coarse particle materials incapable of meeting the fineness requirement return to the grinding bin to continue to be grinded. It is guaranteed that the particle sizes of the grinded fine powder are uniform and kept within a certain range, unreacted calcium hydroxide isfully exposed, the specific surface area of the fly ash is increased, the utilization rate of the calcium hydroxide in the fly ash can be improved to be 80% or over, and continuous industrial production can be achieved. Meanwhile, phosphate is fed into the non-medium grinding machine so as to pre-stabilize heavy metal and reduce the application amount of follow-up deacidification agents, and thephosphate also has the grinding assistance function. A strong oxidant is added and achieves the desulfurization and denitration function and the function of promoting dioxin to decompose.

Description

technical field [0001] The invention belongs to the technical field of recycling and disposal of solid waste, and in particular relates to a method for recycling fly ash from domestic garbage incineration. Background technique [0002] The survey results show that at present, the ratio of lime consumption to fly ash production in most waste incineration power plants in China is as high as 1:3 to 1:2 on average, that is, lime contributes about 30% to 50% of fly ash. Regions even reach 80%. According to the new standard GB18485-2014 for pollution control of domestic waste incineration in my country, the 24-hour average value limit standard of HCl is changed from 100mg / m 3 (GB18485-2001) reduced to 50mg / m 3 ; The new EU incineration standard (2000 / 76 / EC) requires that the daily average concentration of HCl should not exceed 10mg / m 3 . In order to ensure that the flue gas discharge meets the standard, most waste incineration enterprises adopt the method of spraying more lime...

AI Technical Summary

Problems solved by technology

[0006] In order to solve the defects that the fly ash is directly returned to the garbage incineration flue gas treatment system for recycling, the effective components are not fully exposed, the recycling rate is low, and continuous industrial application cannot be realized. Part of the fly ash is ground, sorted, activated and then returned to the flue gas treatment system. This method can greatly increase the specific surface area of ​​the fly ash, efficiently use the unreacted deacidification agent in the fly ash, and reduce the waste incineration flue gas treatment. The amount of deacidification agent and heavy metal stabilizer in the system can be reduced to reduce the total production of fly ash and realize industrial continuous operation

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