Modelagem e simulação da drenagem ácida de mina em colunas

• Ano de defesa: 2010
• Autor(a) principal: Cláudio Marcelo Bernardes de Souza
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Minas Gerais; UFMG
• Palavras-chave em Português: colunas; Drenagem ácida de mina; modelagem e simulação; Engenharia metalúrgica; Tecnologia mineral
• Link de acesso: http://hdl.handle.net/1843/BUOS-8DRHW7

Acid Mine Drainage (AMD) is recognized as one of the most important problem facing the mining industry as it can cause chemical degradation of the aqueous environments. In this study, a hydraulic-kinetic-diffusive model has been developed to describe the AMD phenomena in leaching columns incorporating hydrodynamic and chemical processes. The hydraulic model comprises the 1-D analytic solution of Richards equation assuming the existence of a similarity relationship between thewater retention function and the water content profiles taken at fixed times. The chemical description was developed assuming that pyrite oxidation occurs according to the shrinking core model and that sulfide minerals are uniformly distributed within spherical grains of the host rock that fills the column. The model consists of oxygen balance to evaluate the intrinsic oxidation rate, and pyrite mass balance to evaluate the pyrite fraction reacted with time and column position. A leaching column operation during six months was simulated assuming that the pyriticmaterial was exposed to successive weekly cycles of dry and wet periods. Simulation results demonstrate the formation of acid effluent and consequent increase on the sulfate concentration; both results are comparable with experimental results obtained in columns at laboratory scale, so the model can be a helpful tool in order to propose developing strategies for controlling AMD.