A method of recycling fly ash from domestic waste incineration

Abstract

The invention relates to a recycling method for domestic waste incineration fly ash. A diverter device is installed at the lower end of the dust collector of the waste incineration flue gas treatment system to control the amount of fly ash that circulates into the medialess grinder and prevent the fly ash from agglomerating in the grinding medium or Bonding on the inner wall of the grinder affects the grinding effect. After the fly ash is crushed in the grinding chamber, the high-pressure centrifugal fan will bring the ground powder into the classifier, and the fine powder that meets the fineness requirements enters the circulation system with the airflow, Coarse particles that meet the fineness requirements are returned to the grinding bin to continue grinding, ensuring that the particle size of the ground fine powder is uniform and kept within a certain range, fully exposing unreacted calcium hydroxide, increasing the specific surface area of ​​fly ash, and improving fly ash. The utilization rate of calcium hydroxide in the ash is more than 80%, and continuous industrial production can be realized. At the same time, phosphate is added to the medialess grinder to pre-stabilize heavy metals, reduce the amount of subsequent deacidification agents, and play a grinding role; add strong oxidants to desulfurize and denitrify and promote the decomposition of dioxins.

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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