Process Integration Analysis for Innovative Environmentally Friendly Recovery and Pre-Treatment of Steel Scrap

Abstract

The use of zinc-coated steel (e.g. galvanized steel) in melting cycles based on Electric Arc Furnaces can increase the production of harmful dust and hazardous air emissions. A process to simultaneously preheat and remove the coating from the scrap surface is presented in this paper. The zinc in coating is removed in the gas phase by acid syngas combustion and collected in a dedicated recovery system. The article describes two possible process routes involving plastic waste pre-treatment, shredded plastic gasification/pyrolysis, scrap preheating and zinc recovery processes. The routes have been modelled in an integrated flowsheet, in order to allow a comprehensive simulation and optimization of the pre-treatment processes.