Reduced Environmental Impact and Increased Energy and Material Recovery in the Ferro-alloy Industry Through Staged Combustion of Flue Gas Torbjørn Pettersen1; Bernd Wittgens2; Olaf Trygve Berglihn2; Balram Panjwani2; Benjamin Ravary3; Edin Myrhaug4; 1SINTEF INDUSTRY, 7034 Trondheim, Norway; 2SINTEF, Trondheim, Norway; 3ERAMET NORWAY, Trondheim, Norway; 4ELKEM AS, Trondheim, Norway; PAPER: 54/Iron/Plenary (Oral) SCHEDULED: 12:35/Tue./Mar Azul (50/1st) ABSTRACT: The Norwegian ferro-alloy industry is a world leader in sustainable production of ferro-silicon, silicon, and manganese alloys. Even if the industry is currently operating with very low specific energy consumption, there is a considerable amount of energy available in the off-gas from the submerged arc furnaces, both in terms latent heat and unconverted chemical energy. For FeMn production, the off-gas also contains mineral rich particles which are contaminated by tar and polycyclic aromatic hydrocarbon (PAH) components. The dust particles are currently removed from the off-gas and deposited as a wet sludge waste stream. Results from recent experimental validation are presented for a new concept for off-gas processing, which enables an increased energy recovery and can facilitate future material recovery through production of tar and PAH free mineral dust. New results from a techno-economic evaluation of the concept will be presented, including ideas for material recovery from the currently unutilized waste stream. The overall objective is a maximized energy recovery and simultaneously prepare for a comprehensive reduction of waste streams. References: [1] Y. Ladam, M. Tangstad, and B. Ravary, "Energy mapping of industrial ferroalloy plants", presented at the The thirteenth International Ferroalloys Congress, Almaty, Kazakhstan, 2013, pp. 919-925. [2] S. Gaal, M. Tangstad, and B. Ravary, "RECYCLING OF WASTE MATERIALS FROM THE PRODUCTION OF FeMn AND SiMn", presented at the The Twelfth International Ferroalloys Congress Sustainable Future, Helsinki, Finland, 2010. [3] B. Wittgens, B. Panjwani, T. Pettersen, R. Jensen, B. Ravary, and D.-O. Hjertenes,"SCORE: Staged Combustion for Energy Recovery in Ferro-alloy Industries - Experimental Validation", Infacon XV Int. Ferro-Alloys Congr., 2018. |