Step-by-step flotation detoxification method for fly ash of medical waste incineration

Abstract

The invention discloses a sub-step flotation and detoxification method for incineration fly ash of medical garbage. The sub-step flotation and detoxification method is characterized in that coseparation of dioxin and a carbon component is realized by first-step flotation, so that the toxicity of organic pollutants including the dioxin and the like in the fly ash is reduced; meanwhile, soluble heavy metal is eluted; second-step flotation of tail slurry is subjected to a sulfide precipitation flotation method and heavy metal including Pb, Zn and the like is removed and recycled, so that the harms of the heavy metal are eliminated. Separated final products mainly comprise enriched carbon, residual ash, heavy metal sediment salt and the like, wherein the enriched carbon rich in the dioxin is conveyed into a garbage incinerator secondary incineration chamber to be incinerated, so that the high-temperature decomposition of the dioxin is realized by a low cost; the volume and the toxicity of the residual ash are greatly reduced and the residual ash is directly conveyed into a municipal solid waste landfill to be safely treated or reutilized, so that the subsequent treatment cost is greatly reduced; the heavy metal in the fly ash is leached with an acid and vulcanized and then is precipitated, floated and recycled, so that a plurality of purposes are realized. The method can realize harmless treatment and resource utilization of the incineration fly ash of the medical garbage under environment-friendly and low-cost conditions.

Description

technical field [0001] The invention relates to a method for treating environmental pollution, in particular to a method for treating fly ash from incineration of medical waste. Background technique [0002] Fly ash produced by incineration of medical waste is extremely harmful due to the enrichment of a considerable amount of toxic substances such as dioxins (PCDD / Fs) and heavy metals, and has been included in the "National Hazardous Waste List". Most domestic medical waste incineration fly ash is only temporarily piled up or simply landfilled, which poses a huge safety hazard. For this reason, the national standard GB16889-2008 provides a temporary disposal method, which allows it to be disposed of in domestic waste landfills after treatment. This expedient measure cannot fundamentally eliminate the environmental pollution caused by fly ash incineration of medical waste . There are obvious differences between medical waste incineration fly ash and domestic waste incinera...

AI Technical Summary

Problems solved by technology

This method of sedimentation-filtration to separate heavy metals tends to have some shortcomings: for example, the precipitation time is too long, resulting in incomplete filtration, resulting in the waste liquid containing high concentrations of heavy metals mixed into the residual ash, which makes the heavy metals in the residual ash relatively high, and the residual ash must be processed before final disposal. May also need washing or stabilization, complicated process, etc.

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