Basically different blends are prepared in the Arcelor coke plants that incorporate coals of various ranks, LV, MV, HV, non-coking coals. A comprehensive comparison of these coal blends, within the Arcelor coke plants, has been performed using two successiveapproaches : characterization of each blend at laboratory scale ; coking tests performed in the CPM 400 kg Movable Wall Oven. CSR can be maintained to very satisfying values if coals entering in the blend composition are strictly selected as regards factors like rank and ashes composition. Non-fusible components decrease thecoking pressure, impair the mechanical indices and the CSR. Thislimits their incorporation below 10 %. Industrial results confirm theeffect of the addition of LV non-coking coals : the pushing forces arereduced, the flue temperatures must be increased to keep thestability of the cokemaking parameters and the coke quality isdecreased.

Apart from installation of new batteries, there exist other options forkeeping respectively increasing the production capacity of a cokepiant. Economic and environmental requirements have to be takeninto consideration ieading to very simple solutions such as heatingup of old batteries which have been cooled down followed by partialhot repairs, through-wall repairs and pas up rebuilds. Modernizations with regard to anchoring systems, heating conditions and reduction of typical emissions may be implemented in most cases.

To precede the energy and environmental demands, a follow-up ofthe coke oven batteries was made, to identify the probable causesof pollutants generation and thermal losses. The results of thefollow-up of the in/out gases of the coke ovens led to a change ofthe traditional operational practices, aiming at reducing the airemissions and the energy consumption of the coke ovens.

CST has among its priorities the sustainable development and basedon it the sinter plant unit has a commitment to reduce the atmosphericemissions, by developing actions that assure the continuousimprovement on process and the development of equipment linkedwith environmental control, and also with raw materials consumed inthe process. This paper aims at showing all evolutions on theenvironmental control at the sinter plant, with reference to dust andSO2 emissions, and also the visibility of the plume stack.

The increase of the demand for hot metal made it necessary toanticipate the relining of Rogesa No. 4 blast furnace. At the sametime, the furnace has been enlarged in order to reach a dailycapacity of 6,400 t. The work has been carried out under a consortium of Paul Wurth and SMS Demag with many subcontractingcompanies. The performances on the site have been verysuccessful so that the original schedule could be reduced from 99to 90 days. At maximum there have been more than 600 peopleworking on the site and above al1 without any accident. The totalbudget amounted to 60 M Euro for the furnace itself and to 20 M Euro forthe slag granulation system.

The modernization of a wide-strip hot-rolling mill with the doubleobjective of reducing production costs and satisfying the increasingdemands of the market represents a lower investment than theconstruction of a new mill, but is connected with the considerationof highly complex aspects. The authors present three projectsshowing the approach used by VOEST-ALPINE Industrieanlagenbau (VAI) and the results obtained.

The 3rd octave chatter in cold rolling mills is a major issue for theindustrial production of thin sheets with very tight tolerances, likepackaging steels for instance. In this context, an experimental andtheoretical approach, completed in partnership by Arcelor and VAI,afforded a precise analysis and innovative results, in the followingfields : global on-line tandem mill instrumentation and efficient signaltreatments implementation ; clear differentiation between brummer (non divergent mode) and chatter (divergent mode) ; modelling ofinteractions between chatter and technology (analytical and F.E.approaches) ; advanced chatter monitoring and industrial implementation.

The high corrosion resistance afforded by Zn + 5wt.% Al coatings isfurther improved by low level additions of Mg in the galvanizing bath.The effect of Mg additions on the microstructure and on the properties of the coatings has been investigated. Phase field modellingwas used to simulate the influence of Mg on the eutectic microstructure. Experimental results on the effect of Mg on the ductilityand on the corrosion resistance of the coating are also reported.

XPS and Auger spectroscopies are oflen used in several fields ofactivity of the steel industry that may be sorted into three items :defectology and expertise, research and development on productsand process, study of metallurgical mechanisms. In these fields ofactivity the results, that we provide our customers with, are obtainedwithin the frame of a "Quality insurance - Certification" approach.This approach is based on the appropriate measures taken byArcelor Research to give customers every confidence that any errorof measurement will be prevented. The few examples in this paperdemonstrate how XPS and Auger analysis, performed on samplesof small size to study phenomena at a nanometer scale, can be agreat help to the industrial line management.