Contribuicao da analise de imagem para a modelagem do processo de cominuicao-libertacao de minerios

One of the fundamental problems in Mineral Processing is to know how ores can be comminuted and how the minerals are distributed in the generated particles. In this work, image analysis and processing techniques were applied to support the development, calibration and validation of simulation models of mineral liberation process by particle size reduction, where the minerals exhibit discriminatory behaviour. Based on images of ore textures, simulation models of fracture lines propagation and particle growth by aggregation of a "powder" were developed. In order to calibrate these models, optimization methods were used to find out the optimal model's parameter values in sense that minimize a given objective function defined as the squared deviation between observed and simulated particle size distribution taking into account the variation of the average grade of the target mineral with particle size. This research activity was supported by an important experimental work, comprising batch ball mill grinding tests, size analysis using sieving, laser beam, cyclosizer and microscopy (image analysis) techniques and chemical analysis by X Ray Fluorescence (XRF), Atomic Absorption and optical and backs catering electrons (BSE) image analysisAvailable from Fundacao para a Ciencia e a Tecnologia, Servico de Informacao e Documentacao, Av. D. Carlos I, 126, 1249-074 Lisboa, Portugal / FCT - Fundação para o Ciência e a TecnologiaSIGLEPTPortuga