Harmless treatment method of waste burning fly ash

Abstract

The invention discloses a harmless treatment method of waste burning fly ash. The method comprises the following steps: 1, fully mixing the waste burning fly ash with a small amount of a microwave coupling agent, adding a proper amount of water, and carrying out granulation molding through a molding machine; 2, embedding the above molded particles with the microwave coupling agent; 3, sending the powder embedded molded particles into an industrial microwave oven, carrying out microwave melting, and screening molten slag and the microwave coupling agent for separation; and 4, returning the separated microwave coupling to be used as embedding powder. The fly ash is internally and externally heated and rapidly molten due to the wave absorption characteristic of the microwave coupling agent and substances in the fly ash, so dioxins in the fly ash are completely decomposed, and most heavy metals are cured; and the separated microwave coupling agent can be recycled. The method overcomes the disadvantages of large energy consumption and low thermal efficiency of traditional melting modes.

Description

Technical field [0001] The present invention involves a method of environmental pollution control, which specializes in a harmless treatment method of waste incineration flying ash. Background technique [0002] Domestic waste incineration power generation technology has the dual benefits of environmental protection and energy, and has become the development direction of urban waste treatment.my country's waste incineration power generation has developed rapidly in recent years. After incineration, it will generate about 3 to 5 % of the fly ash. These incineration flying ash contains a considerable amount of toxic substances such as two evil English and heavy metals. The cumulative effect of the organism will eventually be taken by the human body through the food chain to endanger human survival and health through the food chain.In accordance with the State Administration of Environmental Protection, waste incineration ash is a hazardous waste and must be treated.At present, the ...

AI Technical Summary

Problems solved by technology

At present, the method of landfilling incineration fly ash after cement solidification is widely used in China. The main disadvantages of this method are: (1) It must use a high cement / fly ash ratio, consume a large amount of cement, increase volume and quality seriously, and cannot To achieve the reduction requirements of waste treatment; (2), cement solidification requires sufficient operating time; (3), cement solidification is mainly aimed at stabilizing heavy metals in fly ash, and cannot decompose or stabilize dioxins in fly ash, is another Achilles' heel

(4) Heavy metals such as Zn, Pb, and Cd with excessive leachability in fly ash mainly depend on maintaining a relatively stable chemical state in the alkaline environment provided by cement, and are physically stable in the solidified body. After the cement solidifies, the heavy metals will eventually Accumulated in the environment, its long-term stability cannot be guaranteed, and complete harmlessness cannot be achieved

(5) The stabilized products are useless and non-renewable resources, and the resource utilization of incineration fly ash cannot be realized

The traditional melting method needs to heat the fly ash from an external high temperature (≥1400°C) to the molten state, which consumes a lot of energy and high operating costs; in addition, for the electric melting furnace, the high chlorine and high carbon in the fly ash will bring Erosion of refractory materials and burning of graphite electrodes and other adverse effects; fuel-type melting furnaces need to rely on a large amount of auxiliary fuel and air to maintain high temperature, which will produce a large amount of flue gas containing volatile heavy metals, and complex exhaust gas purification facilities need to be equipped after the kiln

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