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Taranto, Italy

Lorenzi A.,University of Parma | Rastelli D.,University of Parma | Biavati A.,Bormioli Rocco S.p.A. | Poncini M.,Bormioli Rocco S.p.A. | And 5 more authors.
Journal of Environmental Chemical Engineering | Year: 2015

The steel industry produces large amount of wastes, some of which are today used in other industrial sectors; iron oxide rich wastes are difficult to recycle and vitrification is one of the most efficient techniques to stabilize them and produce materials suitable for new applications. The waste considered in this study comes from the purification of fumes captured by hoods during agglomeration process in the sinter plant. These dusts have been vitrified on a laboratory scale by the addition of glass cullet coming from diversified harvest of municipal waste, varying the glass/dust ratio from 80:20 to 50:50. The as produced materials have been characterized by means of XRD analysis and SEM images, and leaching tests have been carried out to evaluate their chemical stability. The electrical and magnetic properties of these iron rich materials have been evaluated too. The resistivity of the samples produced with 45% and 50% of waste are 20 and 1.5 × 103 Ω m respectively, considerably lower than the common soda-lime glass resistivity value (1012 Ω m). Moreover the materials show a ferromagnetic behaviour; the Curie Temperature of the materials lies in the range from T = 395°C to T = 533°C, confirming the presence of magnetite/maghemite phases. © 2014 Elsevier Ltd. All rights reserved. Source


Branca T.A.,SantAnna School of Advanced Studies | Pistocchi C.,SantAnna School of Advanced Studies | Pistocchi C.,ETH Zurich | Colla V.,SantAnna School of Advanced Studies | And 7 more authors.
Metallurgical Research and Technology | Year: 2014

The goal of zero-waste is one of the main challenges of modern steel industry, which over the past 20 years has been committed to increase the recovery and the use of by-products generated during the ironmaking and steelmaking processes. Among the main by-products generated during iron and steel production, such as slags, dusts and sludges, slags constitute about 90% of the total. Slags are currently used in various fields (such as cement production, road construction, environmental recovery in landfill covers, as fertilizer and soil conditioner, etc.) according to their chemical features, which depend on production process origin. In Italy, in particular for example, BF (Blast Furnace) slag is used for cement production while BOF (Basic Oxygen Furnace) slag without iron (inert slag) is used as landfill cover, in compliance with Italian legislation. In Germany, BF and BOF slag use as fertlisers and liming materials has a long tradition. Although in recent years slag use has increased, the application for agriculture purposes needs to be further investigated. Slag can be used as a soil conditioner (high content of Ca and Mg), Si supply (improves the crops resistance to pests and diseases), P fertilizer production and micro-nutrients supply. Use of slags can affect human health and environment, because of heavy metal content, which can leache to groundwater or be transferred to surface water. The assessment of risk to the environment based on slag application requires further investigation. This represents an opportunity for both the steel and fertilizer industries to promote natural resources savings, CO2 emission reductions, landfill waste prevention as well as social awareness of sustainability of some industrial activities. The BOF slag has been shown to be useful as liming material for acidic soil amendment and it can replace commercial fertilizers. Different effects on crop yields and on soil parameters can be found, depending on soil characteristics and climate conditions. In Middle Europe, with humid climate, lime losses through leaching of up to 0.5 t CaO/ha have to be replaced with liming material to prevent acidification. Evaluation of long-term field trials with slag liming materials can give information about the impact of slag applications on crop management and the environment. In Mediterranean regions, such as in Italy, arable soils rarely show acidic characteristics. Alkaline soils from coastal areas are often rich in sodium content, due to seawater intrusion and irrigation with saline water. The aim of this research is also to investigate the application of BOF slag to these soils, in order to assess the effect of Ca contained in slag in balancing negative Na effects. This paper is based on the preliminary study and experiments carried out within an ongoing RFCS (Research Fund for Coal and Steel) project. © EDP Sciences 2014. Source


Colla V.,SantAnna School of Advanced Studies | Branca T.A.,SantAnna School of Advanced Studies | Rosito F.,ILVA SpA | Lucca C.,ILVA SpA | And 2 more authors.
Journal of Cleaner Production | Year: 2015

The research work presented in this paper is related to water reuse and facility management concepts for the main circuits in different steel plants through the salt elimination techniques. In particular the study concerned two water circuits belonging to two integrated steelworks where high salts concentrations caused relevant problems. In the first circuit, the high chloride and carbonate concentration in the cooling water of the hot strip mill can affect the quality of the strips, due to the salt depositions on the strip surfaces, and causes corrosion of equipment. In the second circuit, the high content of chlorides and fluorides in the process waters of a Blast Furnace gas cleaning system causes corrosion of various components.In both cases tests were carried out to assess the possibility to apply Reverse Osmosis implementation and to evaluate the stability of its qualitative performance to the brackish water. The tests showed that pre-treatments are actually needed for colloids removal, and, consequently, to protect Reverse Osmosis membranes: in the first circuit, ultrafiltration, and in the second circuit conventional coagulation-flocculation-sedimentation system followed by sand filtration have been implemented.Results showed that, through Reverse Osmosis system, most salts, such as chlorides, fluorides, calcium, sulphates, etc. can be removed and other parameters, such as electrical conductivity, alkalinity and Total Dissolved Solids dramatically decreased. Accordingly significant results have been achieved, such as fresh water consumption and water discharged decrease, and the pipe service life improvement, due to the reduction of corrosion problems. The economic viability at industrial scale was also evaluated and their implementation resulted feasible. © 2015 Elsevier Ltd. Source


Vannucci M.,SantAnna School of Advanced Studies | Colla V.,SantAnna School of Advanced Studies | Corbo G.,ILVA SpA | Fera S.,ILVA SpA
Revue de Metallurgie. Cahiers D'Informations Techniques | Year: 2010

This paper describes a model for the simulation of the process of direct reduction of iron ore for steel production. The model is implemented through stand-alone software and the simulation results have been compared with real experimental data. The very good agreement between the actual and simulated data proves that the model, despite its relative simplicity, takes into account all the fundamental phenomena of iron ore reduction. © EDP Sciences. Source


Matino I.,SantAnna School of Advanced Studies | Colla V.,SantAnna School of Advanced Studies | Romaniello L.,ILVA SpA | Rosito F.,ILVA SpA | Portulano L.,ILVA SpA
2015 World Congress on Sustainable Technologies, WCST 2015 | Year: 2015

Resource efficiency has always been a hot topic for the steel industry, due to the large amounts of primary raw materials, by products and water, which are handled in the steelmaking cycle as well as the considerable energy consumptions. The ever more stringent environmental regulations also contribute to pressurize the iron and steel industry to strengthen further its research activities fostering an optimal management and exploitation of resources. Thus important research efforts are spent in order to find the best way to recover wastes and wastewater also involving the implementation of retrofit actions and major plant modifications allowing also the reduction of primary raw material consumption and of waste disposal. In order to achieve such ambitious objective, which implies both environmental benefits and cost savings, process integration is a powerful tool. The assessment of the viability of process integration solution necessarily include a final experimental stage to be performed at plant level, which can be expensive or unsafe. To this aim process simulation can be a useful alternative to accomplish preliminary feasibility studies allowing a deep analysis of all the aspect of a particular technology or retrofit actions, which also allows testing conditions that are very difficult to replicate within practical experiments. Different levels of detail can be achieved and a comprehensive analysis can be carried out. The present paper provides an overview of the simulation techniques exploited during the project entitled «Efficient Use of Resources in Steel Plants through Process Integration» to the aim of optimizing the use of resources in an Italian integrated steelmaking plant. In particular, different case studies are proposed and the obtained meaningful and practical results are presented and discussed. © 2015 Infonomics Society. Source

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