In 2003, the blast furnaces in Sollac Lorraine faced the challenge ofensuring self sufficiency in coke while maintaining a constant productionlevel. This challenge has been taken up successfully byreducing the coke ratio and by increasing PCI. This was achieved bychanging the tuyeres conditions, by optimizing burden quality andburden charging and improving the wall heat control.

A comprehensive approach is presented to optimise coking coalblends. It includes a first calculation of CRI and CSR for the set ofcoals, confirmed by laboratory carbonisation tests and later completedby carbonisation tests at pilot scale. This approach is expectedto afford a helpful instrument for the coke plant operator.

Raw material yard management and the feeding of the blast furnacesare essential processes for an integrated steelwork, and for CSTin particular as the Company plans to raise their annual output from5 to 7.5 Mt. Accordingly, CST has developed a model of raw materialsupply that takes into account every step of the cycle. The modelincludes two complementary modules, one for supply andconsumption of the raw materials and the other one for raw materialstransport. The model has revealed the need for a significantincrease of the conveyor capacity and has made it possible to definemore appropriate priority rules.

Up to now, no model or contactless sensor has been available foron-line control of the effectiveness of the flow of the stirring gas inthe ladle in secondary metallurgy. A new method, based on the useof conoscopic holography, has been developed by Arcelor-Aceralia.It measures on line the vibrations in the walls of the ladle and relatesthem to the argon flow rate. This method is useful for determiningthe real state of the stirring process, obtaining an accurate index ofthe process of melt agitation that influences the composition homogeneityand cleanliness.

Most steel grades undergo a ductility trough in the temperaturerange 700 to 1100 °C that may bring about surface cracks in the CCstrands.
Micro-mechanical modelling of the as solidified austenite-ferritemicrostructure, supported by experimental evaluations of the fracturesurfaces, affords a comprehensive description of the crack formationmechanism. This opens the way for a quantitative evaluationof the sensitivity of CC strands to transverse cracks.

Civil engineering structures may suffer accelerated damage from thecorrosion of their carbon steel reinforcement bars. This corrosion originatesfrom the carbonatation of concrete that lowers the pH andfrom the diffusion of chlorides through the concrete. It generatesheavy maintenance and repair costs and it significantly reduces theservice life of the structures. These consequences can be avoidedwith the general or partial use of stainless steel reinforcement bars.This solution affords many advantages:
Significant reduction of the maintenance costs.Increased sustainability.Reduced service costs.Improved safety.Optimized concrete thickness.
The limited extra cost of stainless steel rebars over carbon steelrebars is quickly overcompensated for by the savings that they allowon maintenance costs.

A mortality study was carried out among workers employed in theArcelor and GTS Industries plants in Dunkerque. It was aimed atassessing the possible association between iron oxide exposuresand lung cancer risk. The cohort comprised 16,742 males and 959females. Among males, the observed mortality was lower thanexpected for all causes. No significant lung cancer excess was observedfor exposure to iron oxides and no dose-response relationshipwith intensity and duration of exposure.