A method for recycling waste fly ash in iron ore sintering process

Abstract

The invention discloses a method for recycling fly ash from garbage during sintering of iron ore. The method comprises the following steps: uniformly mixing fly ash from garbage, biocarbon and a part of an iron-containing raw material from sintering raw materials and with high valuable metal content, preparing sphere kernels in advance, then wrapping the surfaces of the sphere kernels with fine-granule magnetite so as to form core-shell-structured spheres, subjecting the spheres to low-temperature drying and dehydrating and spreading the spheres on the ground floor of a sintering machine to replace a conventional finished-agglomerate grate-layer material; and subjecting other sintering raw materials to granulation, then spreading the granulated sintering raw materials on the spheres, and carrying out ignition and sintering. The method provided by the invention allows fly ash from garbage to be effectively solidified during sintering of iron ore, and dioxins in the fly ash are efficiently degraded; valuable metals in the core-shell-structured spheres are volatilized into flue gas in a heating section and effectively recovered through capturing in the procedure of flue gas dedusting; and thus, the purpose of recycling of the fly ash from garbage during sintering of iron ore is achieved.

Description

technical field [0001] The invention relates to a treatment method of garbage fly ash, in particular to a method for resource utilization of iron ore sintering co-processing garbage fly ash, and belongs to the technical fields of iron and steel metallurgy and garbage incineration fly ash treatment. Background technique [0002] Waste incineration fly ash is the fine particulate matter captured in the flue gas purification system and heat recovery system (such as economizer, waste heat boiler, etc.) of waste incineration plants. It is an inevitable product of waste incineration, accounting for about 3~ 5%. In my country, due to the failure to effectively classify waste before incineration, the incineration fly ash contains easily leached heavy metal pollutants and highly toxic dioxins. According to the "National Hazardous Waste List" implemented on August 1, 2016 It shows that waste incineration fly ash belongs to HW18 category, which is hazardous waste. If it is not treated ...

AI Technical Summary

Problems solved by technology

In my country, due to the failure to effectively classify waste before incineration, the incineration fly ash contains easily leached heavy metal pollutants and highly toxic dioxins. According to the "National Hazardous Waste List" implemented on August 1, 2016 It shows that waste incineration fly ash belongs to HW18 category, which is hazardous waste. If it is not treated effectively, it will cause secondary pollution to the environment and have adverse effects on human health. Therefore, it is important to choose an appropriate treatment method for the healthy development of human life. significance

[0003] At present, the main treatment methods of waste incineration fly ash and their disadvantages are: (1) Cement solidified landfill

But in fact, the content of harmful elements such as Cl, K, Na, Pb, Zn in the fly ash is high, on the one hand, there is a risk of increasing the residual amount of harmful elements in the sinter, on the other hand, the high temperature conditions in the sintering process can make the Cl in the fly ash and The combined parts of K, Na, Pb, Zn, etc. volatilize into the flue gas, and form ultrafine particles PM after condensation 2.5 , and the current conventional electrostatic precipitator is difficult to remove fine dust, resulting in increased environmental pollution in the sintering process, these problems have not been well resolved in the prior art

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