DIGITAL MULTISPECTRAL TECHNIQUES AND AUTOMATED IMAGE-ANALYSIS PROCEDURES FOR INDUSTRIAL ORE MODELING

The choice of suitable beneficiation strategies is strictly linked to the precise mineral-petrographic, textural and structural characterisa tion of the ore. Careful analysis and precise modelling of spatial rel ationships between different mineralogical phases constituting the ore is the basis of any procedure which aims at forecasting the separatio n results. The textural and structural characterisation of the ore on a macro/microscopic scale is carried out through optical microscopy an d in some special cases by SEM analysis. The main purpose of these pro cedures is that of obtaining information which can be used in numeric form as data for the models. The traditional procedure consists of ana lysing sections under the microscope to obtain distribution maps for t he different mineral phases and making a synthesis of these data so th at they can be easily managed inside a numeric procedure. In the last few years the development of procedures based on techniques of optical image processing has greatly reduced the analysis time, allowing a be tter characterisation of the ore in textural and structural terms. The growing development of research in electronics and computer science a nd the subsequent availability of hardware and software products, allo w handling and processing of full colour digital images, at lower and lower costs. In this paper the problems arising from the adoption of s uch a digital approach both in terms of quality of results (mineralogi cal species automatic identification) and in terms of further processi ng of the data (morphological and morphometrical characteristics and a ssessment of the mineral species constituting the ore), are described and discussed.