Method and device for preparing road snow-melting agent by using waste incineration fly ash

Abstract

The invention relates to a method and a device for preparing a road snow-melting agent by using waste incineration fly ash. The method comprises the following steps: mixing the waste incineration fly ash with semicoke, then adding the mixture into molten sodium chloride for reaction, and introducing chlorine gas into the molten sodium chloride during reaction; discharging fly ash fused salt generated during reaction from the molten sodium chloride, and precipitating the fly ash fused salt at the bottom of the molten sodium chloride to obtain fly ash fused salt slag, and collecting the fly ash fused salt at the bottom to obtain the road snow-melting agent; condensing and collecting volatile gas generated during reaction, and then recycling the chlorine gas. The device comprises a device for implementing the method. According to the treatment method, the process is simple, the volume of the fly ash is reduced by 50 percent, the weight of the fused salt slag is reduced by 50 percent, and a volume reduction rate and a weight reduction rate are obvious.

Description

technical field [0001] The invention belongs to the field of environmental protection for the disposal and comprehensive utilization of hazardous solid waste, in particular to a technology and method for harmless disposal of waste incineration fly ash. Background technique [0002] Carry out the heavy metal leaching test on the original fly ash, according to HJ / T300-2007 national environmental protection industry standard: solid waste leaching toxicity and leaching method, acetic acid buffer solution method, carry out heavy metal leaching concentration test, compare the national "domestic waste landfill pollution control standard 》GB16889-2008, confirming that fly ash is a hazardous waste. [0003] There are many disposal techniques for traditional waste incineration fly ash. Specifically, it is divided into four categories: separation and extraction technology; heat treatment technology, solidification and stabilization technology and other technologies. However, there is...

AI Technical Summary

Problems solved by technology

[0007] With the improvement of people's living standards and environmental awareness, the chemical composition of waste incineration fly ash has also undergone significant changes. The prominent features are high salt content and high calcium oxide content, which makes traditional melting technology encounter difficulties. Without the addition of co-solvent, the melting temperature of waste incineration fly ash exceeds 1500°C, coupled with secondary fly ash treatment, extremely high energy consumption, unprecedented technical difficulties in the melting process

However, even if the sintering technology is adopted, the sintering temperature is very high, and the salt in the fly ash directly affects the quality of the sintered product. Water washing and desalting treatment is required before sintering, which increases the cost and complicates the process, and the risk of heavy metal leaching of the sintered product still exists

[0008] With the cement mixed firing process after washing, the cement production capacity is excessive, the amount of cement clinker fired is small, the concentration of chloride ions at the kiln tail increases, and the hidden danger of kiln tail preheater skinning increases, and many technologies such as chloride salt recovery, filter hardening, etc. Problems make cement blending also face many difficulties

[0009] Most of the traditional road deicing agents are mixtures of chlorine salts, and the preparation cost is high

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