CHARACTERIZATION OF THE COMPOSITION OF SOLID MIXTURES USING PARTICLE-SHAPE DISTRIBUTIONS OBTAINED BY IMAGE-ANALYSIS

There are many applications of particle technology in which solid mixt ures consisting of particles having the same chemical, mineralogical a nd physical properties are used. The particles are then distinguishabl e only by shape. The particle shape significantly influences the techn ological behaviour of the mixture and the properties of the materials produced. Therefore, mathematical procedures are necessary in order to determine the composition of such a mixture according to the proporti ons of certain particle shape classes. These classes are the respectiv e components of the mixture. In this work, various statistical methods were tested to classify the particles by shape analysis. A two-compon ent mixture of quartz and muscovite was used as a reference material. The results obtained by different theoretical methods were compared wi th each other. Alternative methods such as histogram fit and the EM al gorithm provided better results than the conventional method of discri minant analysis, as expected. Because the statistical behaviour of the components can be estimated only using reference samples, a statistic al error of about 5-10% depending on the respective sample size was me t. However, this is a satisfactory result. It turned out that it is po ssible to conclude exclusively on the basis of the particle shape dist ribution about the composition of a mixture. The methodical knowledge obtained can be used in industrial applications such as the ceramic in dustry, the production of paints and the bulk solids technology.