Method and system for co-processing waste incineration fly ash by using rotary hearth furnace

Abstract

The invention discloses a method and system for co-processing waste incineration fly ash through a rotary hearth furnace, and the system for co-processing waste incineration fly ash through the rotary hearth furnace comprises a material mixing machine, a ball press machine, a drying machine, the rotary hearth furnace, a waste heat boiler and a dust removal device.The method comprises the steps that after ferrous metallurgy dust and mud, waste incineration fly ash, a binder and water are evenly mixed, the mixture is heated to the room temperature; the method comprises the following steps: firstly, preparing a metal pellet, pressing into pellets to obtain carbon-containing pellets, then drying the carbon-containing pellets, feeding the carbon-containing pellets into a rotary hearth furnace, carrying out reduction roasting to obtain metallized pellets and zinc-containing flue gas, and then carrying out heat exchange and dust removal on the zinc-containing flue gas to obtain zinc-containing dust. According to the method, the waste incineration fly ash and the ferrous metallurgy dust sludge are cooperatively treated in the rotary hearth furnace, the dezincification rate and the metallization rate of the ferrous metallurgy dust sludge are increased through the waste fly ash, the using amount of a binder is saved, the cost is reduced, meanwhile, the content of dioxin in the waste incineration fly ash is reduced, and the environment friendliness is achieved. And harmless treatment and resource utilization of the waste incineration fly ash and the ferrous metallurgy dust sludge are achieved.

Description

technical field [0001] The invention belongs to the fields of metallurgy and energy, and in particular relates to a method and a system for co-processing waste incineration fly ash by utilizing a rotary hearth furnace. Background technique [0002] The iron and steel metallurgical production process will produce a large amount of metallurgical dust and sludge. At present, most domestic enterprises use the rotary hearth furnace method to treat them. The rotary hearth furnace direct reduction process has higher recovery rate of valuable elements such as iron and zinc, lower energy consumption, less pollution, and higher added value of products; therefore, the rotary hearth furnace direct reduction process has become an effective method for the treatment of iron-containing dust and sludge. One of the best choices, this process is characterized by high temperature and rapid reduction, the metallization rate can reach 65-75%, and the dezincification rate can reach 85-90%. [000...

AI Technical Summary

Problems solved by technology

At present, the relatively safe disposal processes are: 1. Fly ash treatment methods include cement coagulation and solidification treatment-landfill; 2. Chemical agent treatment-landfill; 3. Melting treatment-recycling; 4. Cement kiln co-processing Among them, cement kiln co-processing is widely used, but cement kiln co-processing of fly ash only realizes the harmless disposal of waste fly ash, and does not realize resource utilization, and the chlorine element in the fly ash will affect the cement clinker Quality affects

[0004] Application No. CN200910103892.7 discloses a method for harmless and recycling treatment of garbage fly ash by using ironmaking blast furnace. The method uses ironmaking blast furnace as the processing device, and sprays garbage fly ash in the blast furnace with pulverized coal Mixed into coal powder before, through the blast furnace coal injection process, the mixture of coal powder and garbage fly ash is sent into the hearth of the blast furnace, or the garbage fly ash is mixed into the recycled pellets used in the ironmaking blast furnace, and the garbage fly ash mixed The regenerated pellets are sent to the ironmaking blast furnace as a common raw material for ironmaking blast furnace ironmaking——the pellets are used for normal smelting, and the high temperature and reducing atmosphere in the hearth area of ​​the blast furnace are used to achieve fly ash treatment and recycling However, this technology mixes garbage fly ash into pulverized coal to reduce the calorific value of pulverized coal, which leads to an increase in coal consumption. At the same time, the chlorine element in garbage fly ash has a fatal impact on refractory materials during the melting process.

[0005] Application number CN201711495720.X discloses a system and method for making ecological cement by co-combusting waste fly ash and sludge in a cement kiln, including a sludge pretreatment unit, a waste fly ash storage unit, a batching storage unit, a material mixing system, an incineration device, clinker storage device, cement kiln system; the incineration device is sequentially equipped with an air lock feeder, a vertical incinerator, an air lock valve, and a chain plate discharger; the present invention adds cement to sludge and garbage fly ash Kiln ash and coal powder are incinerated to prepare ecological cement; however, in this technology, the co-processing of waste fly ash in cement kilns has strict requirements on the chlorine element in the fly ash, and the chlorine element in the fly ash needs to be removed in advance by water washing process, resulting in increased disposal costs, and At the same time, the production of cement clinker has strict ingredients, restrictions on the composition of waste fly ash, and limited use of technology

[0006] Application number CN201710335944.8 discloses a dioxin control method for iron ore sintering co-processing garbage fly ash process. The method is to mix and granulate the four components of garbage fly ash, lime milk, flammable solid fuel and sludge , drying to obtain pellets containing garbage fly ash; iron ore sintering raw materials are granulated and mixed with the pellets containing garbage fly ash, and then ignited and sintered after cloth; but this technology adds garbage fly ash to the sintered ore It will reduce the iron grade, and the strong oxidizing atmosphere in the sintering system will easily cause the secondary generation of dioxin

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