Iron recovery from the waste generated during the cutting of granite

Autor(es)

Junca, E. ^[1] ; de Oliveira, J. R. ^[2] ; Espinosa, D. C. R. ^[1] ; Tenorio, J. A. S. ^[1]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Dept Engn Met & Mat, BR-05508900 Sao Paulo - Brazil

^[2] Inst Fed Espirito Santo, Dept Engn Met, BR-29040780 Vitoria, ES - Brazil

• Tipo de documento: Artigo Científico
• Fonte: INTERNATIONAL JOURNAL OF ENVIRONMENTAL SCIENCE AND TECHNOLOGY; v. 12, n. 2, p. 465-472, FEB 2015.
• Citações Web of Science: 1

Resumo

Metallic iron is present in the waste left when granite blocks are cut. Thus, the purpose of this study was to characterize this waste using chemical and particle size analyses. To achieve this, X-ray diffraction and scanning electron microscopy coupled with electron back-scattered diffraction were used. To find the method with the best metallic iron recovery from the waste of ornamental rock, three distinct methods were examined: magnetic separation, table concentration and cyclone processing. The first method involved three steps: (1) use of a wet high-intensity magnetic separator, where only the equipment's remaining magnetic field was present; (2) the material from the first step was then submitted to separation again, this time using a magnet for rare earth particles; and (3) this material after two separation processes was finally submitted to ferromagnetic separation. The second method used a concentration table set at various inclinations, oscillation frequencies and wash flow rates. Meanwhile, for the third method, the cyclone tests, only the water pressure was varied. After each test, a chemical analysis was performed to determine the metallic iron present in each sample. The tests revealed that magnetic separation presents the best results. Using this technique, a ferrous concentrate with 93 % metallic iron content and a granite concentrate with only 0.6 % metallic iron were obtained. On the other hand, in the table concentrator tests, the ferrous concentrate only had a metallic concentration of 13.6 %. In separation by the cyclone processing, the product barely contained metallic iron (7.2 % maximum). (AU)

• Processo FAPESP: 08/53194-9 - Estudo da separação e aproveitamento da parte metálica e dos óxidos presentes no resíduo gerado no corte de rochas ornamentais
• Beneficiário: Jorge Alberto Soares Tenório
• Linha de fomento: Auxílio à Pesquisa - Regular