scholarly journals A combined hydro-pyrometallurgical process for zinc oxide and iron oxide extraction from electric arc furnace dust waste

2021 ◽  
Vol 945 (1) ◽  
pp. 012027
Author(s):  
Hwang Sheng Lee ◽  
Yao Yi Teo
Keyword(s):  
Zinc Oxide ◽  
Iron Oxide ◽  
Liquid Solution ◽  
Extraction Process ◽  
Electric Arc Furnace ◽  
Electric Arc ◽  
Arc Furnace ◽  
Pyrometallurgical Process ◽  
Eaf Dust ◽  
Iron Leaching

Abstract Electric arc furnace (EAF) dust waste is generated during EAF steelmaking process. Zinc and iron which comprise the highest composition in EAF dust are secondary resources for making steel products. They mainly present in the form of stable zinc ferrite (ZnFe2O4), leading to the extraction process difficult. In this study, a combined hydro-pyrometallurgical process was developed to extract both zinc oxide and iron oxide from EAF dust. Initially, hydrometallurgical leaching was used to leach zinc and iron from EAF dust. Results show that 10 M of hydrochloric acid (HCl) at 25°C can achieve zinc and iron leaching of 92% and 91%, respectively. The liquid solution post leaching was subjected to pyrometallurgical process to form Fe2O3 mixture at 250°C while retaining zinc chloride (ZnCl2) as solid residue. Then, the obtained ZnCl2 was treated with sodium hydroxide (NaOH) and nitric acid (HNO3) to form ZnO. The Fe2O3 and ZnO extraction were 2.5 g and 1.5 g, respectively out of 10 g of EAF dust with their respective purity of 87% and 98%. The developed process can provide new insight into recovering zinc oxide and iron oxide simultaneously from EAF dust, thereby paving the way to circular economy development and sustainable steel dust waste management for steel industries.

Electric Arc Furnace Dust Treatment Process by Iron Powder

2015 ◽  
Vol 656-657 ◽  
pp. 428-433
Author(s):  
Sureerat Polsilapa ◽  
Piyakarnt Khamsriraphap ◽  
Panyawat Wangyao
Keyword(s):  
Zinc Oxide ◽  
Iron Powder ◽  
Zinc Ferrite ◽  
Electric Arc Furnace ◽  
Electric Arc ◽  
Arc Furnace ◽  
Pyrometallurgical Process ◽  
Electric Arc Furnace Dust ◽  
Eaf Dust ◽  
High Zinc

Electric arc furnace dust is a byproduct from steelmaking, contained up to 50%wt of zinc ferrite. It also contains about 10-20%wt of zinc oxide and the other metal oxides. Approximately 100,000 tons of EAF dust are generated per annum within Thailand. All of the dust has been sent to landfill. The objective of this research is to investigate the kinetics mechanism of the decomposition of zinc ferrite in EAF dust to obtain zinc oxide and iron oxide by using iron powder as a reducing agent. The process was carried out by mixing zinc ferrite or EAF dust with iron powder then compressed them in a mold. The samples from compression were treated by pyrometallurgical process. The factors required to be concerned were temperatures, particle sizes of iron powder, and mole ratios of zinc ferrite per iron powder, respectively. The treated samples were analyzed by X-ray diffraction (XRD) in order to characterize zinc ferrite phase transformation. It was found that the quantity of zinc ferrite, both either pure zinc ferrite and zinc ferrite in EAF dust, were decreased after treating by the pyrometallurgical process when increasing treating time from 30 to 180 minutes at 600°C, the particle size of iron powder at 10 micron, and the mole ratio of zinc ferrite per iron powder at 1:3. Moreover about 70%wt of zinc ferrite was decomposed and the products obtained were zinc oxides (ZnO) and iron oxides (Fe3O4, FeO, Fe2O3). The reduction of zinc ferrite with iron powder was well-defined taking place by diffusion thru product layer control. The activation energy of the reduction process was found to be 47.21±2.83 kJ/mol. Therefore, the decomposition of zinc ferrite by iron powder could be carried out at 1 atm with low pyrometallurgical temperature (600°C) and equipped with hydrometallurgical process to obtain high zinc yield.

Turning Electric Arc Furnace Dust Waste into Oil Spot Ceramic Glaze

2016 ◽  
Vol 690 ◽  
pp. 33-38 ◽  
Author(s):  
Wantanee Buggakupta ◽  
Chanyanud Tianthong ◽  
Sirithan Jiemsirilers
Keyword(s):  
Zinc Oxide ◽  
Iron Oxide ◽  
Electric Arc Furnace ◽  
Electric Arc ◽  
Raw Material ◽  
Toxic Waste ◽  
Arc Furnace ◽  
Fine Particulates ◽  
Ceramic Glaze ◽  
Eaf Dust

Electric Arc Furnace (EAF) is commonly used in steel recycling industries. Apart from steel metal product, a waste in the form of dust is also produced and so called EAF dust. The fine particulates mainly contain zinc-iron oxides along with a small amount of heavy metals like chromium and lead, and have been categorized as a toxic waste. Proper treatments can be crucially required in order to recover crude zinc oxide and iron oxide from the dust; however, no practical recycling plants have been now readily operated in Thailand. To reduce its toxicity, EAF dust could be mixed with silica-based materials and vitrified into glass. Therefore, EAF dust can possibly be employed as a ceramic glaze raw material. This work pointed out how to make decorative “oil spot” ceramic glaze by substitution of EAF dust for a conventional iron oxide. The prepared glaze mixtures were applied over the ceramic bodies and fired at 1250 °C in oxidation atmosphere. The as-fired glaze appearances with tiny and silvery crystals floating over dark brown based-glaze were exhibited. Phase content and characteristics of the obtained glaze were analyzed. The roles of zinc oxide to iron oxide ratios on oil spot and crystal generation was concerned. A comparison of oil spot effects due to different iron oxide sources was presented and discussed. Oil spot glaze made from a combination of EAF dust and iron oxide powder was also proposed.

scholarly journals Briquetting of EAF Dust for its Utilisation in Metallurgical Processes

2015 ◽  
Vol 36 (2) ◽  
pp. 263-271 ◽  
Author(s):  
Aneta Magdziarz ◽  
Monika Kuźnia ◽  
Michał Bembenek ◽  
Paweł Gara ◽  
Marek Hryniewicz
Keyword(s):  
Shaft Furnace ◽  
Steel Production ◽  
Hydrated Lime ◽  
Electric Arc Furnace ◽  
Electric Arc ◽  
Arc Furnace ◽  
High Iron Content ◽  
Coke Content ◽  
Eaf Dust ◽  
To Receive

Abstract Dust generated at an electric arc furnace during steel production industry is still not a solved problem. Electric arc furnace dust (EAF) is a hazardous solid waste. Sintering of well-prepared briquetted mixtures in a shaft furnace is one of possible methods of EAFD utilisation. Simultaneously some metal oxides from exhaust gases can be separated. In this way, various metals are obtained, particularly zinc is recovered. As a result, zinc-free briquettes are received with high iron content which can be used in the steelmaking process. The purpose of the research was selecting the appropriate chemical composition of briquettes of the required strength and coke content necessary for the reduction of zinc oxide in a shaft furnace. Based on the results of the research the composition of the briquettes was selected. The best binder hydrated lime and sugar molasses and the range of proper moisture of mixture to receive briquettes of high mechanical strength were also chosen and tested. Additionally, in order to determine the thermal stability for the selected mixtures for briquetting thermal analysis was performed. A technological line of briquetting was developed to apply in a steelworks.

scholarly journals Steelmaking Dust: Speciation of Zinc by Sequential Leaching

2020 ◽  
Vol 2 (1) ◽  
Author(s):  
Christof LANZERSTORFER ◽  
Wilfried PREITSCHOPF
Keyword(s):  
Zinc Content ◽  
Electric Arc Furnace ◽  
Electric Arc ◽  
Water Soluble ◽  
Dust Particles ◽  
Chemical Fractionation ◽  
Arc Furnace ◽  
Eaf Dust ◽  
Gas System ◽  
Main Component

In electric arc furnace (EAF) steelmaking significant amounts of dust are generated. The main component in the dust is usually iron.Additionally, increased concentrations of metals which are volatile in the steelmaking process like zinc are found in the dusts. Duringcooling of the off-gas in the off-gas system the volatile metals are deposited on the dust particles. In electric arc furnace dust the zinccan be present in different compounds, for example as zinc oxide and zinc ferrite. Although recycling of EAF dust and utilization forzinc recovery are practiced in several countries approximately 50% of the EAF dust produced worldwide is still goes to landfill. In thisstudy the EAF dust from a mini mill was investigated by chemical fractionation. The experiment was carried out in a sequence of fiveleaching steps, where the residue from a leaching step was treated in the next step. The total zinc content of the EAF dust was approximately 6.4%. In the water-soluble fraction no zinc was found, while the carbonated fraction and the oxide fraction each containedapproximately 25% of the zinc. The reduced fraction contained approximately 8% of the zinc and the majority of the zinc was in theresidual fraction.

scholarly journals Microstructural, thermochemistry and mechanical evaluation of self-reducing pellets using electric arc furnace (EAF) dust containing zinc for Waelz process

2018 ◽  
Vol 23 (2) ◽  
Author(s):  
Leidy Julieth Hernández Buitrago ◽  
Iván Daza Prada ◽  
Gisele Amaral-Labat ◽  
Flávio Beneduce Neto ◽  
Guilherme Frederico Bernardo Lenz e Silva
Keyword(s):  
Electric Arc Furnace ◽  
Electric Arc ◽  
Arc Furnace ◽  
Eaf Dust ◽  
Waelz Process
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