ENCYCLOPÉDIE DE LA RECHERCHE SUR L’ALUMINIUM AU QUÉBEC 2013 | Page 33

PRODUCTION DE L’ALUMINIUM Application of an Artificial Neural ALUMINIUM PRODUCTION Network to Control the Properties of APPLICATION D’UN RÉSEAU DE NEURONES ARTIFICIELS Baked Anodes 31 POUR CONTRÔLER LES PROPRIÉTÉS DES ANODES CUITES (Application d’un réseau de neurones APPLICATION des artificiels pour contrôler les propriétésOF AN ARTIFICIAL NEURAL NETWORK TO CONTROL THE PROPERTIES OF BAKED ANODES anodes cuites) Dipankar Bhattacharyay1, Duygu Kocaefe1, Yasar Kocaefe1, Brigitte Morais2 Auteur 1, Author2 1Université 2Aluminerie du Québec à Chicoutimi, Département des sciences appliquées, 555, boul. de l’Université, Chicoutimi, Québec, Canada G7H 2B1 1 Département et Institution 1 Alouette Inc., 400, Chemin de la Pointe-Noire, C.P. 1650, Sept-Îles, Québec, Canada, G4R 5M9 2 department and Institution 2. CHAIRE DE RECHERCHE UQAC/AAI SUR LE CARBONE Artificial Neural Network Flow Sheet Experimental Data Normalization of Data Abstract The carbon anodes contribute significantly to the cost of primary aluminum production. The variations in quality of raw materials such as calcined coke, pitch, recycled butts and anodes affect the quality of baked anodes. The goal of the industry is to produce better quality anodes in spite of these variations. In the absence of a distinct mathematical relationship between the raw material properties and those of the baked anodes, the production is usually controlled based on experience. The plants usually maintain a large database. Proper analysis of these data using artificial neural networks (ANN) can help better control the anode production process and improve the anode quality. In this work, the application of an ANN to control the quality baked anodes is demonstrated in the case of variations in raw materials using data from the literature. Results and Discussion Develop Artificial Neural Network Model Initialization Training of the network Adjustments of weight w and bias b The results indicate that it is possible to replace Coke D with other cokes without affecting significantly the baked apparent density, specific electrical resistivity, and Young’s modulus of the baked anodes. Learning Pattern recognition and data classification Validation Compare output with test data set Prediction Predict output using data set for which output is not known Data Used for Analysis Data from a published doctoral thesis (Juraj Chmelar, Size reduction and specification of granular petrol coke with respect to chemical and physical properties, The Norweigian University of Science and Technology, 1992) were used for the analysis. Chemelar used 4 cokes mixed with pitch (15 to 20%), varied the percentage of -63µm coke particles (45 to 94%), and measured different baked anode properties. Properties of Cokes Used Predicted vs. Experimental Values Conclusions ANN is an useful tool for the prediction of anode properties. It can be used as a tool to control the quality of anodes when there are variations in raw materials and process conditions. The major advantage of ANN is that it can efficiently handle highly nonlinear data with noises for which there is no existing mathematical relationship. The development of an efficient ANN model is time consuming because it needs lot of trials and errors; but, once it is developed, it can predict results even if there are no experimental data available. For the training of an ANN, availability of large sets of data is required, but this is generally not a limitation for the industries. Dipankar Bhattacharyay Duygu Kocaefe Yasar Kocaefe Université du Québec à Chicoutimi Brigitte Morais Aluminerie Alouette Inc. Acknowledgements The technical and financial support of Aluminerie Alouette Inc. as well as the financial support of the National Science and Engineering Research Counc