ENCYCLOPÉDIE DE LA RECHERCHE SUR L’ALUMINIUM AU QUÉBEC 2013 | Page 27

PRODUCTION DE L’ALUMINIUM ALUMINIUM PRODUCTION 25 ANALYSES ET CLASSIFICATION DE LA TEXTURE SUPERFICIELLE DU COKE DE PÉTROLE PAR IMAGERIE CLASSIFICATION OF THE SURFACE TEXTURE OF PETROLEUM COKE BY IMAGE ANALYSIS Wilinthon Bogoya-Forero1, Carl Duchesne1 et Jayson Tessier2 1 2 Centre de recherche sur l’aluminium – REGAL, Département de Génie Chimique, Université Laval, Québec, QC, G1K 7P4, Canada Alcoa Canada Primary Metals, Aluminerie de Deschambault, 1 Boulevard des Sources, Deschambault - Grondines, QC, G0A 1S0, Canada 1. Introduction 5. Experimental • Petroleum coke is a by product in the refining of crude oil and is considered by the refineries a waste product. Therefore, the refineries have no incentive to control and/or improve its quality. Calcined petroleum cokes were used as raw materials to evaluate the effect of coke type and particle size distribution on the texture by image analysis. • For the aluminum industry, however, petroleum coke is an essential raw material for the production of anodes. Carbon anodes are manufactured of a mixture of calcined petroleum coke, pitch and recycled anode butts (Fig. 1). UNMIXED COKE MIXED COKE • A shot coke (S) and five sponge cokes A, B, C, D and E were classified as shown in table 1. • Three fractions were mixed in different proportion. Table 1. Particle size distribution of coke Fraction Fig. 1. The framework for reducing variability in baked anode manufacturing plants • The aim of this work is to reduce the variability of coke properties in the raw materials used for making baked anodes. Particle size + 4.75 mm - 4.75 / + 2 mm Coarse (C) - 2 / + 1 mm - 1 / + 0.6 mm - 600 / + 300 mm Intermediate (I) - 300 / + 180 mm Fine (F) - 180 mm (-) The particles pass through the sieve. (+) The particles are retained by the siev