REMOVING ZINC FROM GALVANIZED STEEL SCRAP TO FEASIBLE THE BOF SLUDGE RECYCLING
Galvanized steel scraps generated at Usiminas Ipatinga are recycled in BOF converters. Although they are noble products, they contain a significant quantity of zinc that escapes from the bath due to its high vapor pressure and is captured by the gas control system, appearing in BOF sludge. As BOF...
| Main Authors: | , , |
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| Format: | Article |
| Language: | English |
| Published: |
Associação Brasileira de Metalurgia, Materiais e Mineração
2013-06-01
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| Series: | Tecnologia em Metalurgia, Materiais e Mineração |
| Subjects: | |
| Online Access: | http://www.tecnologiammm.com.br/files/v10n2/v10n2a03.pdf |
| Summary: | Galvanized steel scraps generated at Usiminas Ipatinga are recycled in BOF converters. Although they are noble
products, they contain a significant quantity of zinc that escapes from the bath due to its high vapor pressure and is
captured by the gas control system, appearing in BOF sludge. As BOF sludge contains high iron content, it could be
recycled to the process, but due to its zinc content, it is disposed in landfills. For this reason, this study aimed to treat
these scraps to remove zinc layer using a thermal treatment process. The samples were fed to a rotative furnace in an
inert ambient. It was tested the hot dip galvanized and eletrogalvanized scraps, varying the zinc coating weight between
20g/m2 and 150g/m2, temperature between 700°C and 900°C and time between 3 minutes and 10 minutes. Considering
these conditions, it is verified that more than 70% of the zinc layer is removed at 700°C, in 10 minutes. Dust captured
is about 60% of metallic zinc and 40% as zinc oxide. Based on these results, the recycling of BOF sludge can be feasible
to the ironmaking process. |
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| ISSN: | 2176-1515 2176-1523 |