Kinetic investigation of synthetic zinc ferrite reduction by hydrogen

Junca, Eduardo; Grillo, Felipe Fardin; Restivo, Thomaz Augusto Guisard; Oliveira, José Roberto de; Espinosa, Denise Crocce Romano; Tenório, Jorge Alberto Soares

doi:10.1007/s10973-017-6222-7

Cited by 13 publications

(3 citation statements)

References 27 publications

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“…8). This result is consistent with the results found in other studies [6,17]. Gang Yu carried out a similar study and successfully reduced ZF partially by using CO as a reductant [18].…”

Section: Reduction Of Zinc Ferritesupporting

confidence: 92%

Selective Extraction of Zinc from Zinc Ferrite

Kashyap

Taylor

2020

Mining, Metallurgy & Exploration

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The presence of iron in sphalerite induces the formation of zinc ferrite (ZF) during roasting. Zinc refinery residues (ZRR) and electric arc furnace dust (EAFD) contain a significant amount of zinc ferrite and are difficult to treat. According to the literature, up to 71% ZF has been found to be present in ZRR. The dissolution of zinc ferrite is inefficient even in aqua regia. The Waelz process is an existing process to recover zinc from electric arc furnace dust by reduction using carbon monoxide followed by the volatilization of zinc. In this study, zinc was selectively extracted from zinc ferrite by partial reduction of zinc ferrite at relatively low temperature followed by leaching in dilute sulfuric acid (20 g/L). Pure zinc ferrite samples were partially reduced to zinc oxide and magnetite by using H 2 gas as a reductant. The presence of magnetite and zinc oxide was confirmed by X-ray diffraction (XRD) technique. A maximum of 95% zinc extraction was achieved after leaching with sulfuric acid on the reacted samples. The paper also discusses the effect of time, temperature, and concentration of H 2 in the reducing gas on the extraction of zinc and iron from ZF.

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“…8). This result is consistent with the results found in other studies [6,17]. Gang Yu carried out a similar study and successfully reduced ZF partially by using CO as a reductant [18].…”

Section: Reduction Of Zinc Ferritesupporting

confidence: 92%

Selective Extraction of Zinc from Zinc Ferrite

Kashyap

Taylor

2020

Mining, Metallurgy & Exploration

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“…Figure 10b shows that the increase in diameter of the pellet decreases the reaction rate, suggesting that mass transfer in the pores hinders the reduction of iron-ore pellets and that the diffusion mechanism influences the pellet reduction process 33,34 . However, at the start of reduction, pellet diameter has a weaker effect on the reduction, thereby suggesting the participation of other mechanisms besides diffusion.…”

Section: Kinetic Investigationmentioning

confidence: 99%

Green Ironmaking Industry: Production of Iron Pellets Using Lime Sludge

et al. 2023

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The use of alternative raw materials is essential for establishing a circular economy in the mineral and ironmaking sectors. Therefore, this study investigates the potential of lime sludge as fluxing material during pelletization and proposes an alternative route for the usage of waste. The pellets were manufactured with different binary basicity values (CaO/SiO 2 ) (0.15-0.45) and bentonite (0.5-0.7 wt%) and fixed carbon (0.5-1.1 wt%) contents. The results demonstrated that lime sludge has significant potential for application in pelletization. Pellet quality was evaluated using drop number, mechanical strength, tumble index, porosity, and kinetic analyses. Pellets with the optimal composition using lime sludge withstood 3.6 drops/pellet, a tumble test of 1.57 wt.%, and a mechanical strength test of 214.83 kgf/pellet and exhibited a porosity of 31.28%. Lime sludge did not influence the reducibility of the iron-ore pellets. In the temperature range of 800-900 °C, the reaction was controlled by diffusion, with E a between 179.89 and 233.10 kJ/mol.

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“…ZnFe2O4 + 8 NH4Fe(SO4)2 = ZnSO4 + 5Fe2(SO4)3 + 8NH3 + 4H2O (5) In this process, the ¼ part of the sulfate content of the ammonium iron(III) alum turns into SO3 in the zinc ferrite sulfation process. According to this, the 1:8 molar ratio is the minimal ZnFe2O4:alum molar ratio.…”

Section: Reaction Of Znfe2o4 With Ammonium Iron Alum (Nh4)2fe2(so4)2mentioning

confidence: 99%

Recycling the industrial waste ZnFe2O4 from hot-dip galvanization sludge

Fekete

Lázár

Keszler

et al. 2018

J Therm Anal Calorim

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In this study, the goal was to find lower temperature for separating the Zn and Fe content of ZnFe2O4 by sulfation reaction than previously achieved, and to study the various reactions steps of sulfation. Hence, the reaction of ZnFe2O4 with Mohr's salt containing iron(II), i.e. (NH4)2Fe(SO4)2•6H2O, and ammonium iron alum containing Fe(III), i.e. NH4Fe(SO4)2•12H2O was studied. At first the thermal decomposition of precursor salts in air was studied by TG/DTA-MS to find the proper temperature for sulfation. Then ZnFe2SO4:precursor salt mixtures with ratios 1:2 and 1:5 were prepared and annealed at 400, 425, 450 °C. The solubility of the products obtained at different annealing temperatures in water (e.g. ZnSO4, FeSO4, Fe2(SO4)3) and in HCl (Fe2O3, ZnO, Fex(OH)ySO4, Znv(OH)wSO4 basic sulfates) was studied. The morphology and structure of the starting materials was investigated by SEM, XRD and FTIR, the crystalline phases after each annealing and washing steps were studied by XRD. The Fe in the starting materials and the products obtained at 425 °C was measured by Mössbauer. Based on the obtained results,

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Kinetic investigation of synthetic zinc ferrite reduction by hydrogen

Cited by 13 publications

References 27 publications

Selective Extraction of Zinc from Zinc Ferrite

Selective Extraction of Zinc from Zinc Ferrite

Green Ironmaking Industry: Production of Iron Pellets Using Lime Sludge

Recycling the industrial waste ZnFe2O4 from hot-dip galvanization sludge

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