Rotas de processo para concentração de rochas itabiríticas da Mina Lagoa das Flores, Itatiaiuçu, MG

• Ano de defesa: 2011
• Autor(a) principal: Joao Antonio Vasconcelos
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Minas Gerais; UFMG
• Palavras-chave em Português: Engenharia Metalúrgica e de Minas; Engenharia metalúrgica
• Link de acesso: http://hdl.handle.net/1843/BUOS-8MSFXS

The present waste piles of the Mina Lagoa das Flores, belonging to the Minerita Minérios Itaúna Ltda Company, are composed by three typologies of poor itabirites (37%Fe): compact itabirite, semicompact itabirite and amphibolitic itabirite. Therefore, this work firstly focused on determining the size distribution, liberation degree and chemical analyses, as well as the mineralogical and microstructural characterization of these typologies, and later the development of concentration routes through bench-scale tests using magnetic concentration, flotation and the combination of both. The mineralogical and microstructural characterization showed that all the itabirite samples went through a martitization process with the presence of magnetite relicts preserved inside the martitic hematite grains and a great incidence of trellis structure. The martitic hematites showed different porosity degrees besides many inclusions of quartz, with diameters varying from 10m to 40m, what did not allow the obtaining of sinter-feed. In general the several studies indicated an average mass recovery of 48% through magnetic separation by medium and high magnetic fields, followed by flotation. This route can result in the production of 960,000t/year of pellet-feed with average content of iron and quartz of 66.00%Fe and 2.60%SiO2, considering that all waste itabirites generated nowadays at the Mina Lagoa das Flores were processed. Therefore, the use of these waste itabirites would provide an increase in the mines mass recovery of 41.82% to 60.40%. This would result in a total production of 250Mt of pellet-feed originating from waste itabirites during 235 years for the same scale of current production and geological reserve, without considering the amount of waste stocked in the piles. However, due to need of ultrafine grinding and the high abrasivity rate verified for the compact itabirite sample, which contributed with most of the waste generated, thefragmentation stages will be clearly the greatest difficulty in the recovery of these itabirites because of the high operational cost