Etudes de libération des minerais à l'Université Laval (Quebec)

CIM Bulletin, Vol. 76, No. 850, 1983

M.A. BERUBE et J.C. MARCHAND Le Groupe de Recherche en Automatisation, Appliquee a I'lndustrie Minerale, Departement de Mines et Metallurgie, Departement de Geologie, Universite Laval, Quebec

The main objective of ore grinding is to liberate the valuable minerals from the gangue so that afterwards concentration can be easily achieved with the best yield. The current practice is to try to maintain constant the particle size distribution of the grinding product. Unfortunately, the textural properties of ore minerals present natural variations in a deposit and this practice does not necessarily lead to a constant ore liberation. Thus, for optimal performance of the concentration process, this very important variable must be controlled periodically. Up to now, studies of mineral liberation are usually done by inspection of polished sections showing mineral particles. GRAAIM recently assembled a modular image analyzer which will be mainly devoted to the automatic measurement of the degree of mineral liberation. The cost of this system is relatively low compared to the conventional texture analysers considering that most of the associated units, such as the minicomputer, are shared with other applications. Such a modular system has great versatility because the software can be handled and modified at will. Algorithms have been developed to automatically study the liberation of minerals on polished sections. They also allow the measurement of the grade and of the apparent particle size distributions. Results obtained with iron ores are briefly presented.
Keywords: Traitement du minérai, Analyse d'images, Libération des minérais, Vroyage, Degré de libération, Traitement des données, Automatisation