Study on stainless steelmaking dust agglomeration

Abstract

A new direct recycling technology was developed to recover the valuable metals present in the stainless steelmaking dust and protect the environment. The agglomeration behavior of the dust was analyzed to ensure the requirements of the direct recycling. The main characteristics such as strength, leachability, structure and chemical composition of the pellets were investigated. SEM images show a significant amount of porosities affecting the strength of the pellets and the arrangement of particles in the pellets reveals that no recrystallization bonds are formed, resulting in the poor strength of the pellets. When lignosulfonate is applied as the binder for the agglomeration and the green pellets are dried at room temperature for 60 h, the strong pellets can be obtained without milling the dust. The result of leachability tests shows that the pellets agglomerated can not satisfy the regulations set by the environmental protection agency of US. And it will cause some environmental problems in the long storage of pellets.

Keywords

property of pellet / agglomeration / stainless steelmaking dust / recycling

References

[1] ZunkelD. What to do with your EAF dust [J]. Steel Times International, 1996, 20(4): 46-50

[2] NyirendaR L. The processing of steelmaking flue dust: a review[J]. Minerals Engineering, 1991, 4(11): 1003-1025

[3] SouzaN D, KozinskiJ A, SzpunarJ AEAF stainless steel dust, characteristics and potential metal immobilization by thermal treatment[A], 1998, Calgary, Mineral and Metallurgical Institute

[4] PengJi, PengBing, TangMo-tang, et al.. Thermo-analytical study of stainless steelmaking dust[J]. Journal of Central South University of Technology, 2003, 10(4): 301-306

[5] HagniA M, HagniR D, DemarsC. Mineralogical characterization of electric arc furnace dusts [J]. Journal of Metals, 1991, 43(3): 28-30

[6] PengBing, ZhangChan-fu, PengJi, et al.. Kinetics research of EAF dust reduction in isothermal condition[J]. Journal of Anhui University of Technology, 2000, 18(1): 13-17(in Chinese)

[7] ZhangChuan-fu, PengBing, PengJi, et al.. Electric arc furnace dust non-isothermal reduction kinetics[J]. Transactions of Nonferrous Metals Society of China, 2000, 10(4): 524-530

[8] PengBing, LobelJ, KozinskiJ A, et al.. Non-isothermal reduction kinetics of EAF dust-based pellets[J]. CIM Bulletin, 2001, 94(1049): 64-70

[9] PietschWSize Enlargement by Agglomeration[M], 1991, New York, Wile Press

[10] US EPAToxicity Characteristics Leaching Procedure (TCLP)[M], 1986, Brisbane, Federal Register: 40643-40645

[11] PengBing, PengJi, ZhangChuan-fu, et al.. Thermodynamics calculation on the oxidation and sulfur removal ability of slag in EAF dust pellet reduction process[J]. Journal of Central South University of Technology, 2001, 8(1): 64-68

[12] ZhangChuan-fu, PengBing, PengBing, PengJi, et al.The direct recycling of electric arc furnace stainless steelmaking dust[A], 2001, Gyeongiu, The Korean Institute of Resources Recycling

[13] RuzickovaZDevelopments in mineral processing: Pelletization of Fines [M], 1988, New York, Elsevier Science Publishing Company

[14] LobelJ, PengBing, BourassaM, et al.. Pilot-scale direct recycling of flue dust generated in electric stainless steelmaking (II)[J]. Iron and Steelmaker, 2000, 27(1): 41-45

[15] LobelJ, PengBing, KozinskiJ A, et al.Pilot-scale direct recycling of flue dust generated in electric stainless steel-making (I)[A], 1999, Pittsburgh, Iron and Steel Society