There are many heavy metals in electric arc furnace dust, which need to be treated, otherwise it will seriously pollute the environment.
What is electric arc furnace dust?
1. Electric arc furnace dust generation is divided into three smelting stages: melting, oxidation and reduction. The amount of dust and pollutants in EAF are different in each smelting stage. In the oxidation stage, the furnace dust is the largest, and the furnace gas produced by 1T tons of steel is 80~100m3. The actual amount of furnace gas entering the dust removal system is determined according to the way of flue gas collection, which is generally more than 10 times larger than that of furnace gas.
2. In the melting stage, grease combustibles and metals in the charge are burned at high temperature to produce black and brown smoke.
3. The oxidation stage is the decarbonization process, and the oxidation of iron produces a large amount of russet smoke.
4. During the reduction phase, oxygen and sulfur are removed from the steel, and toner is added to adjust the chemical composition of the steel, producing a black or white smoke.
The dust discharged by electric arc furnace is mainly air pollutant, producing 12~14kg dust from 1T ton of steel. At high temperatures in an arc furnace, metals are sublimed, oxidized, and cooled to form iron oxide particles less than 0.01 m. Dust and rust are discharged together with furnace gas.
Is electric arc furnace dust hazardous waste?
Electric arc furnace dust is hazardous waste, The chemical composition of electric arc furnace dust is mainly iron oxide, other components are related to the smelting of iron and steel and raw materials, if there is galvanized scrap steel in the raw material, the smelting process of zinc sublimation and oxidation to produce zinc oxide.
The waste gas of eAF consists of CO2, CO, NOX, SO2 and cyanide, etc. The consumption of graphite electrode, the grease in scrap steel, the evaporation and decomposition of water, the melting and decarburization of scrap steel all have influences on the content.