Composite ferric salt targeted chelating agent for treating waste incineration fly ash and use method of composite ferric salt targeted chelating agent

Abstract

The invention discloses a composite ferric salt targeted chelating agent for treating waste incineration fly ash and a use method thereof. The chelating agent comprises ferric sulfate, ferrous sulfate and at least one of goethite, ferrihydrite and siderite. The use method comprises the following steps: mixing the waste incineration fly ash, the composite ferric salt targeted chelating agent and water, and curing to form a solidified body. The composite ferric salt targeted chelating agent has the advantages of low cost, no toxicity, harmlessness, good solidification and stabilization effects on different types and occurrence forms of heavy metals and soluble salts, obvious volume reduction effect of a formed solidified body, good stability and the like, is an environment-friendly chelating agent with excellent performance, and can be widely used for treating waste incineration fly ash. According to the method, the waste incineration fly ash can be solidified and stabilized, the pollutant concentration of the leachate can reach the standard, the capacity increasing ratio of the obtained solidified body is smaller than 1.3, the compressive strength is larger than or equal to 1.1 MPa, and the solidified body is good in stability, small in secondary dissolution risk, high in use value and good in application prospect.

Description

technical field [0001] The invention belongs to the technical field of fly ash solidification, and relates to a composite iron salt targeting chelating agent for treating waste incineration fly ash and a use method thereof. Background technique [0002] Domestic waste incineration fly ash contains Pb, Cd, Zn, Cr and other harmful heavy metals and salts. If not handled properly, heavy metals will migrate and pollute water, soil and air. In the process of disposal and utilization, the leaching of heavy metals into the ecological environment is the main potential environmental risk of fly ash. The release of heavy metals directly affects the surrounding soil, surface water and groundwater, which can affect plant growth and increase potential toxicity through the food chain. If the leached toxic substances seep into the groundwater, it will directly endanger the ecological environment and human health. [0003] Waste incineration fly ash contains dangerous components such as he...

AI Technical Summary

Problems solved by technology

However, the above-mentioned chelating agent and its treatment process for processing waste incineration fly ash still have the following defects: (1) the chelating agent stabilization approach is single and cannot adapt to the difference in the dissolution characteristics of heavy metals of different types and forms in the fly ash; 2) The chelating agent is toxic and expensive, and the amount of curing agent added is large, which increases the volume significantly; (3) The moisture content of the cured body is high, easy to return frost, and efflorescence, and it is difficult to ensure the strength of the cured body and the stability of the pile for a long time; (4) ) The chelating effect of the solidified body is difficult to maintain for a long time, and there is a risk of secondary dissolution of harmful substances

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