Method for treating incinerated fly ash of domestic garbage with cooperation of cement kiln

Abstract

The invention discloses a method for treating incinerated fly ash of domestic garbage with cooperation of a cement kiln, which comprises the following steps of: 1) washing and pre-treating the fly ash, 2) treating sewage, and 3) calcining cement clinker, wherein the process of washing and pre-treating the fly ash in the step 1) comprises a step of washing the fly ash by using a three-stage washing treatment device consisting of a washing tank and a vacuum filter, and the water and the fly ash are mixed in a weight ratio of 2:1-3:1; the process of treating the sewage in the step 2) comprises steps of desalting supernate and returning the purified condensate water to the step 1) to perform repeated washing so as to realize water recycle; and when the cement clinker is calcined in the step 3), the calcining temperature in the cement kiln can reach 1,750 DEG C. Therefore, the method can ensure that heavy metal ions in the treated fly ash are effectively fixed in crystal lattices of the cement clinker and dioxin is totally decomposed, and realizes hazard-free and reclamation treatment of the fly ash; and the calcined cement can reach the physical and mechanical properties of P.O42.5 cement.

Description

technical field [0001] The invention relates to a treatment method for domestic waste incineration fly ash, in particular to a cement kiln cooperative treatment of domestic waste incineration fly ash to realize the complete harmlessness and resource utilization of domestic waste incineration fly ash Methods of incinerating fly ash. Background technique [0002] Due to the continuous development of cities, the amount of domestic waste has increased dramatically, which has become an important factor restricting urban development. Incineration treatment is one of the most important means of dealing with municipal solid waste at present. However, due to the incineration of domestic waste, the content of chloride salt in the incineration fly ash is as high as 10%, and it contains organic pollutants such as benzopyrene, benzanthracene, dioxin and Cr, Cd, Hg, Pb, Cu, Ni and other trace heavy metals are classified as hazardous waste. [0003] The existing domestic and foreign dom...

AI Technical Summary

Problems solved by technology

However, the use of cement solidification to treat domestic waste incineration fly ash faces the defects of poor solidification and stability of heavy metals and high leaching rate of harmful substances; and landfills occupy a large amount of land resources, and landfills have potential environmental pollution effects on surrounding ecology. is a potential source of sludge

In terms of high-temperature treatment, cement kilns are mainly used to burn cement. Due to the high content of chloride ions in fly ash, not only the disposal capacity of cement kilns is low, but also the normal operation of the kiln system is affected.

[0004] The invention patent application with the publication number 101182144A discloses a "method for recycling domestic waste incineration fly ash in cement kiln" which discloses that the domestic waste incineration fly ash is washed-carbonated and used as cement raw meal and other raw materials Putting it into the cement kiln for pre-calcination, this method can effectively fix the heavy metals in the fly ash in the cement clinker lattice under high temperature conditions; at the same time, the chlorine content in the treated domestic waste incineration fly ash can be reduced to 1%, which provides a feasible method for cement kilns to treat domestic waste incineration fly ash; If the moisture content of the fly ash filter cake is too high, when it enters the cement kiln for calcination through the proportion of raw material, not only the amount of mixing is small, but also has a negative impact on the raw material batching process and the stability of the kiln system.

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