A methodology is proposed for taking recycling, an essential activityof the developed economies, into account within LCA tools. Thereasoning for choosing the methodology is exposed step by step.The final proposal is centered on the multiple-recycling model, whichbest describes the practical way that materials are actually recycledin the economy.
From a practical standpoint, the results obtained are attributed tosteel on the basis of a specific value (e.g. t of CO2 per t of steel),which amounts to averaging the impact over the various steps of therecycling process on a weighted average basis, depending on theamount of material recycled at each step.

The new Brazilian free energy market and the possibilities affordedby the carbon credits motivated a reassessment of Top RecoveryTurbines (TRT), to be installed on blast furnaces 2 and 3 of CST.These turbines could recover about 16 MW electric energy.
Several options have been considered, including energy selling,internal consumption and through Arcelor Brazil consumption,taking also carbon credits into account.

An innovative modelling strategy has been developed and validatedto help the design of steel reheating furnaces. A set of complementarysimulation tools has been used to rethink the furnace concept,namely the Digit@l FurnaceTM, from the burners to the global energysystem optimisation. Several Digit@l FurnacesTM are now in operationon hot rolling mills. Advantages in terms of pollutant emissions,operation costs and flexibility have been demonstrated on site.

The application software “Integrated Solution for Sinter Plant andBlast Furnace Charging” is presented. This is a decision-makingsupport system that includes a mathematical model for the automaticand optimized generation of charging solutions for the sinter plantand blast furnace processes.
This model assures the quality specifications of the products, environmentallimits as well as availability of materials, with particularfocus on the operational stability. Furthermore, it allows managerialanalysis including the acquisition strategies of new consumablesand fuels.

A new mold flux has been developed to favour cuspidine crystallisationat the upper level of the mold. This reduces the local heat fluxand allows an even solidification of the slab shell, thus preventingany occurrence of longitudinal cracks. Pilot tests have establishedthat the new flux make it possible to cast hypoperitectic steel slabsat casting speeds up to 5 m/min.

Use of stainless steel rebar for concrete reinforcement is increasingworldwide. The enhanced properties of stainless steel prove to be aviable solution when life cycle costs of the structures are taken intoaccount. Austenitic and duplex stainless steels are used as rebarbecause they present an excellent combination of corrosion resistancein concrete, high strength and good ductility.
The resistance to pitting corrosion of various stainless steels hasbeen evaluated by electrochemical tests. Thus, it is possible toselect the appropriate grade according to the environment the concretestructure is submitted to during its life. A classification of theselected austenitic and duplex grades is introduced.