Mineral phases of weathered and recent electric arc furnace dust

Martins, Fernanda Machado; Neto, José Manoel dos Reis; Cunha, Carlos Jorge da

doi:10.1016/j.jhazmat.2007.10.041

Cited by 76 publications

(35 citation statements)

References 44 publications

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“…Several researches have mentioned that EAFD is composed of Fe, Zn, Ca, Pb, Cr, Mn, Si, Cd and Ni, where Fe and Zn are the main component [5][6][7][8][9][10][11]. According to Kukurugya, Vindt and Havlík [12], iron and zinc content in EAFD is in the range of 24-45.24 and 8-33 %, respectively.…”

Section: Introductionmentioning

confidence: 99%

Reduction of electric arc furnace dust pellets by simulated reformed natural gas

Junca

Restivo

Oliveira

et al. 2016

J Therm Anal Calorim

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The purpose of this paper is to study the kinetic reaction of electric arc furnace dust pellets using a reducing gas simulating the reformed natural gas. The kinetic investigation was accomplished via forced stepwise isothermal analysis method. The tests were programmed in the range of 500-1000°C. It was used a reducing gas contained 25 % of CO and 75 % of H 2 . X-ray patterns were analyzed in order to understand the reduction process. The results show the reduction of electric arc furnace dust pellet occurs in three steps. At 550-650°C, the zinc ferrite is reduced to magnetite and zinc oxide, followed by the reduction of magnetite to wustite. Carbon deposition on the pellet surface was detected in this step, which impairs the kinetic analysis. In the range of 700-800°C, wustite is reduced to iron. It was determined a mixed control between nucleation and diffusion with E a of 89.2 kJ mol -1 . At 850-950°C, the main reaction is zinc oxide reduction to gaseous zinc. However, wustite reduction is also observed. The E a of 135.5 kJ mol -1 with a mixed control between diffusion and chemical reaction was detected.

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Section: Introductionmentioning

confidence: 99%

Reduction of electric arc furnace dust pellets by simulated reformed natural gas

Junca

Restivo

Oliveira

et al. 2016

J Therm Anal Calorim

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“…Researchers have been shown that the dust generated from electric arc furnace contain 4.8-23.5 % of zinc. These values can vary according to the raw material specific of the plant operation [3][4][5].…”

Section: Introductionmentioning

confidence: 99%

Synthetic zinc ferrite reduction by means of mixtures containing hydrogen and carbon monoxide

Junca

Oliveira

Restivo

et al. 2015

J Therm Anal Calorim

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Solid waste generation is one of the main problems in the steelmaking process. One of the most problematic waste products is the electric arc furnace dust, which is a by-product rich in iron and zinc and is present as zincite (zinc oxide) or franklinite (zinc ferrite). This work focuses on the reduction kinetics of synthetic zinc ferrite by gases containing hydrogen and carbon monoxide. This process was examined via forced stepwise isothermal analysis. The test was conducted at temperatures ranging from 500 to 950°C. Reduction of zinc was accomplished using a mixture of hydrogen and carbon monoxide in order to simulate reformed natural gas. The results indicated that reduction of zinc ferrite occurred in two stages (550-750°C and 800-900°C). The first stage was characterized by iron oxide reduction, where a mix control between nucleation and diffusion was determined. The apparent activation energy obtained was 71.5 kJ mol -1 . The second stage was characterized by zinc oxide reduction, where the controlling mechanism was identified as a mixed control between diffusion and phase boundary reaction. The apparent activation energy was 135.5 kJ mol -1 . The formation of a dense layer of metallic iron around the unreacted core may have caused the apparent activation energy to increase.

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“…[16][17][18] The X-ray diffraction pattern of the sample used in this research shown in Fig. 1 Schematic diagram of the experimental apparatus employed in the present study is shown in Fig.…”

Section: Methodsmentioning

confidence: 99%

Influence of Temperature on the Selective Chlorination and Evaporation Reactions of Zn and Pb in EAF Dust

2017

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Large amount of dust is produced during ironmaking and steelmaking process and it should be recycled or treated for the sake of environmental protection. Particularly, the dust produced in electric arc furnace (EAF) process is quite special because of its abundance in Zn and Pb, which makes it inappropriate for recycling to the conventional steelmaking process. Chlorination and evaporation method is a possible choice to treat the dust, in which Zn and Pb are selectively chlorinated and recovered as gaseous chlorides while the chlorination of Fe can be prevented in its oxidizing atmosphere. In the present study, the feasibility of the selective chlorination and evaporation reaction of Zn and Pb in EAF dust was con rmed in the mixing atmosphere of Cl 2 and O 2 gas (P O2 = 9.0 × 10 4 Pa and P Cl2 = 1.0 × 10 4 Pa). Change of oxide phase with reaction time was also analyzed by XRD measurement. The in uence of temperature on the chlorination and evaporation reaction rate and removal fractions of Zn and Pb was investigated by gravimetric method and composition analyses at the temperature range from 923 K to 1073 K. The chlorination and evaporation rate increased with increasing temperature from 923 to 1073 K and the removal fractions of Zn and Pb after 60 min at 1023 or 1073 K reached approximately 98% and 99%, respectively. Simultaneously, it was con rmed that small portion of Fe was chlorinated and evaporated from the dust in the present experimental conditions.

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Mineral phases of weathered and recent electric arc furnace dust

Cited by 76 publications

References 44 publications

Reduction of electric arc furnace dust pellets by simulated reformed natural gas

Reduction of electric arc furnace dust pellets by simulated reformed natural gas

Synthetic zinc ferrite reduction by means of mixtures containing hydrogen and carbon monoxide

Influence of Temperature on the Selective Chlorination and Evaporation Reactions of Zn and Pb in EAF Dust

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