Method of rapidly removing harmful substance in waste incineration fly ashes

Abstract

Clean water as an extractant for extracting hazardous matters from municipal solid waste incineration (MSWI) fly ash is applied in a low liquid-to-solid (L / S) ratio and high speed stirring condition. Under this condition, the broken MSWI fly ash easily releases much matters into water and also creates high concentration of OH- ion enhancing hazardous species, including Pb species, transform into water soluble species. Therefore, hazardous matters in MSWI fly ash can be quickly removed, and non-hazardous fly ash is obtained and can be further provided for reuse. In the process of this invention, MSWI fly ash and clean water are first prepared, and then high speed stirring extraction at a low L / S condition is accomplished. Thereafter, fly ash slurry is settled for submerging extraction and solid-liquid separation is subsequently carried out. Wastewater generated from solid-liquid separation goes forward to wastewater treatment facility and dewatered fly ash is dried and ground. Finally, grinding fly ash is detected in both of TCLP leaching toxicity and dioxins content. If such detections all pass regulatory limits, the fly ash is non-hazardous and can be further reuse; otherwise, fly ash should be returned to the beginning step for advanced treatment.

Description

technical field [0001] The present invention is related to the technical field of processing harmful fly ash produced by waste incineration. More specifically, it can quickly remove harmful heavy metals and dioxin substances in waste incineration fly ash, so that the detection of fly ash after treatment is lower than the legal standard, and the A method for the rapid removal of hazardous substances from waste incineration fly ash as a harmless and reusable substance. Background technique [0002] The fly ash produced after garbage incineration is often called garbage incineration fly ash. Since the incineration temperature is usually between 850-1050°C, the heavy metals in the garbage that have a lower boiling point than the incineration temperature are easy to gasify. With the exhaust gas and fly ash entering the air pollution control equipment of the incineration plant, the heavy metals condense and most of them adhere to On fly ash. In addition, if there are chlorine-co...

AI Technical Summary

Problems solved by technology

However, this method not only cannot reuse the fly ash, but also increases the waste volume, consumes the limited space of the landfill, and increases the disposal cost; Harmful substances in the cured product dissolve and pollute the water and soil environment

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