EUROPEAN STEEL TECHNOLOGY AND APPLICATION DAYS 2017 - ESTAD 2017

An increased environmental consciousness, more stringent environmental regulations and a raise of raw material costs have characterized the last few years. All these factors affect the industrial chain management and in the case of the steel industry lead to an intensification of the effort to find solutions allowing increasing waste and by-product reuse. The paper presents part of the work carried out in this direction within the European project entitled "Removal of Phosphorus from BOF-slag" (PSP-BOF). Such project aims at obtaining reusable fractions of material from the Basic Oxygen Furnace (BOF) slag. In particular, the paper is focused on the modelling work carried out to develop models that include slag treatment, slag processing and production of reusable products. To this aim, two kind of models were developed and presented. The first model is more complex, considers each treatment process step and allows sensitivity analyses in order to get useful information in case of different slags to be treated or different treatment configurations. The other one is only a material flow-based model that, using the results obtained by the complex model and by the experimentation, which was carried out in pilot scale in a first part of the project, allows the evaluation of the best way to reuse (internally or externally) the obtained slag fractions, considering process and environmental constraints and making optimization assessment. The two developed models have been used to make comparison of the new proposed slags ways with the standard utilization route of an Italian integrated steelworks, in terms of energy and material consumption and process cost estimation, and gives indication about the best way to be followed in order to obtain both environmental and economic advantages.