EM - Escola de Minas
URI permanente desta comunidadehttp://www.hml.repositorio.ufop.br/handle/123456789/6
Notícias
A Escola de Minas de Ouro Preto foi fundada pelo cientista Claude Henri Gorceix e inaugurada em 12 de outubro de 1876.
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2 resultados
Resultados da Pesquisa
Item Utilising starches from sugarcane and cassava residues as hematite depressants.(2020) Marins, Tatiana Fernandes; Rodrigues, Otávia Martins Silva; Reis, Érica Linhares; Beltrão, Jéssica GoulartThe aim of this study is to investigate the actions of sugarcane bagasse and cassava wastewater (two residues from the food industry) when used as hematite depressants. Additionally, the effect of each residue preparation method on the flotation results was analysed. The efficiencies of the depressors were investigated through microflotation tests utilising samples of pure hematite and quartz from Quadrilátero Ferrífero, which is in the state of Minas Gerais (Brazil). The pH of 10.5 was selected due to its frequent use in the concentration of iron ore via flotation in Brazil. Three residue gelatinisation methods (natural, heated, and conventional) were evaluated to determine the most efficient method for the flotation process. Further, zeta potential measurements were performed on the hematite to ascertain the performances of the residues. Microflotation test results showed that hematite recovery decreased with increasing depressant concentration, for all reagents. Finally, the actions of residues gelatinised with the addition of sodium hydroxide (i.e. the conventional method) were shown to be similar to that obtained from corn starch, which indicates their potential application in the flotation process.Item Analysis of quartz floatability using design of experiments.(2019) Matos, Vanderson Eney de; Peres, Antônio Eduardo Clark; Pereira, Carlos Alberto; Nogueira, Stephânia da Consolação SilvaQuartz floatability in cationic reverse flotation depends on the suitable choice of surfactant type and the conditions under which they are applied. The design of experiments (DOE) allows the evaluation of process variables, in a structured and independent way, with statistical validation and a limited number of tests. Tests of microflotation of quartz, in the size range -150 +75 µm, using factorial design of experiments, showed that etherdiamine leads to higher level of quartz floatability than ethermonoamine, favored by increase in collector concentration, at the high level of pH tested (11.0). Floatability values above 90% were achieved with the use of 3 mg/L of ether diamine for both pH levels, while with ether monoamine the target was reached only at pH 11.