Fly ash composite chelating agent, and preparation method and application thereof

Abstract

The invention discloses a fly ash composite chelating agent and a preparation method and application thereof, belonging to the field of treatment of incineration fly ash. The fly ash composite chelating agent comprises the following components: organic agents, NaH2PO4 and Na2S, wherein the organic agents comprise potassium dimethyl dithiocarbamate, sodium diethyl dithiocarbamate, dithiocarbamate and ethylenediamine tetraacetic acid. The fly ash composite chelating agent can undergo a chelating reaction with almost all the heavy metal ions at normal temperature, is good in stabilizing effect, small in use amount, simple in step, low in curing cost and high in practicability, and has high efficiency and economical efficiency in treatment of heavy metals in hazardous waste, namely the incineration fly ash.

Description

technical field [0001] The invention relates to the field of incineration fly ash treatment, in particular to a fly ash composite chelating agent and its preparation method and application. Background technique [0002] Hazardous waste incineration fly ash contains a large amount of heavy metals that are easy to leach. With the implementation of the new version of "Hazardous Waste Landfill Pollution Control Standards" on June 1, 2020, the allowable leaching limit of heavy metals is further strictly controlled. For hazardous waste fly ash in industrial waste disposal sites, the total lead, total cadmium, total zinc, total copper, and total nickel often exceed the standard. Among them, according to the new landfill standard, the total lead is reduced from the original 5mg / L to 1.2mg / L, and the total nickel is reduced from the original 15mg / L to 2mg / L. [0003] The type, formula and addition ratio of fly ash compound chelating agent will affect the stabilization effect of fly ...

AI Technical Summary

Problems solved by technology

At present, the fly ash chelating agents on the market have a single component, mainly inorganic, phosphate, sulfide, small molecule organic chelate, etc. If used alone, the dosage is large, and it has selective chelation for heavy metals, and cannot simultaneously chelate multiple Concentrated Chelation Stabilization of Heavy Metals

Although there is research and development of compound chelating agents on the market, there are still relatively few research and development examples, and it is impossible to concentrate and stabilize multiple heavy metals at the same time, and the stability of the pH value of the chelates is not good.

At the same time, due to the high sales cost of this type of complex chelating agent on the market, the operating cost increases