Iron and zinc-containing dust sludge solid waste treatment method based on whole-process iron and steel enterprise

Abstract

The invention relates to the technical field of iron-containing and zinc-containing dust sludge treatment in the iron and steel industry, in particular to an iron and zinc-containing dust sludge solid waste treatment method based on a whole-process iron and steel enterprise, which comprises the following steps that sintering ash generated by sintering and gas ash of a blast furnace are washed with water, KCl and NaCl in the sintering ash and the gas ash are recovered, and filter pressing is conducted on washing residues to obtain filter residues; the obtained filter residues arefully mixed with gravity ash of a blast furnace, fly ash of a converter and fly ash of an electric furnace, and the mixture is subjected to a high-temperature reduction reaction, steam generated after the generated flue gas sequentially passes through a gravity settling boiler and a waste heat boiler is used for supplying heat; the residual flue gas is subjected to air mixing, dust removal and wet treatment to realize ultralow emission, zinc oxide powder is collected and recycled in the dust removal process, gravity ash subjected to gravity settling serves as a return material to participate in raw material proportioning again, and a metallized product generated by high-temperature reduction reaction is subjected to heat preservation and transfer to be used for steelmaking production. Harmless treatment of solid waste and resource utilization of iron and zinc-containing dust sludge are really realized.

Description

technical field [0001] The invention relates to the technical field of iron and zinc-containing dust and sludge disposal in the iron and steel industry, in particular to a method for solid waste disposal of iron and zinc-containing dust and sludge in iron and steel enterprises based on the whole process. Background technique [0002] Iron and steel enterprises will inevitably produce a large amount of iron-containing dust and sludge during the production process. Taking a steel enterprise with a production capacity of 10 million tons as an example, the annual production of iron-containing and zinc-containing dust and sludge is 500,000-800,000 tons (dry basis). These dusts contain valuable elements such as iron and carbon, but also harmful elements such as zinc. For a long time, most of the iron-containing dust and sludge produced are directly returned to sintering for utilization, and some of them are stockpiled in the factory or disposed of in a rotary hearth furnace, etc. ...

AI Technical Summary

Problems solved by technology

The accumulation of iron-containing dust and sludge leads to the enrichment of heavy metals in areas such as steel plant sintering, which causes heavy metals in regional drainage to seriously exceed the standard

[0005] 3) Disposal in rotary hearth furnace: At present, iron-containing zinc-containing dust and sludge are mostly disposed of in a rotary hearth furnace, and the raw materials are mostly dust and sludge in ironmaking and steelmaking processes, and the disposal of dust and sludge in the sintering process is not considered

At the same time, the disposal process mostly adopts the direct treatment of raw materials, and the resource utilization of dust and sludge is not considered to the maximum; the raw materials contain a large amount of chlorine, potassium, sodium and other elements. During the operation of the rotary hearth furnace, chlorine, potassium, sodium and other elements are Gas enters the waste heat boiler, resulting in increased corrosion and dust accumulation of the waste heat boiler

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