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 Batch removal of manganese from acid mine drainage using bone char.(2014) Sicupira, Dalila Chaves; Silva, T. Tolentino; Leão, Versiane Albis; Mansur, Marcelo BorgesThe present study investigated batch kinetics and the batch equilibrium of manganese removal from acid mine drainage (AMD) using bone char as an adsorbent. Equilibrium tests revealed that the Langmuir-based maximum manganese uptake capacity was 22 mg g-1 for AMD effluents and 20 mg g-1 for laboratory solutions at a pH ranging from 5.5 to 5.7. The pseudo-second order model best described the manganese kinetics within bone char. Manganese removal was mainly influenced by the operating variables of the solid/liquid ratio and the pH of the aqueous phase. In fact, metal uptake was favored at nearly neutral pH values. The effect of particle size and temperature proved to be insignificant for the investigated operating range. This work also evaluated the mechanism for manganese removal using bone char. Results showed that intraparticle diffusion is the main rate-limiting step; however, additional contributions from boundary layer diffusion may well affect this removal when particles of smaller sizes are used. The final concentration of fluoride and other metals present in the AMD effluent was in agreement with the concentration limit set forth by Brazilian legislation. The present study demonstrated that bone char is a suitable material to be used for the removal of manganese from AMD effluents.Item Manganese and limestone interactions during mine water treatment.(2010) Silva, Adarlêne Moreira; Cruz, Flávio Luciano dos Santos; Lima, Rosa Malena Fernandes; Teixeira, Mônica Cristina; Leão, Versiane AlbisManganese removal from mining-affected waters is an important challenge for the mining industry. Addressed herein is this issue in both batch and continuous conditions. Batch experiments were carried out with synthetic solutions, at 23±2 ◦C, initial pH 5.5 and 8.3 g limestone/L. Similarly, continuous tests were performed with a 16.5 mg/L Mn2+ mine water, at 23 ◦C, initial pH 8.0 and 20.8 g limestone/L. Calcite limestone gave the best results and its fine grinding proved to the most effective parameter for manganese removal. In either synthetic solutions or industrial effluents, the final manganese concentration was below 1 mg/L. A change in limestone surface zeta potential is observed after manganese removal and manganese carbonate formation was suggested by IR spectroscopy. The conclusion is that limestone can remove manganese from industrial effluents for values that comply with environmental regulations.