Results of industrial converter operation have been analyzed withseveral approaches, based on statistics or on the kinetics of thevarious reactions. Cogent results have also been obtained throughthe follow up of gas emissions. The kinetics models that have beendeveloped constitute a significant contribution to the implementationof new strategies for converter operation.

The control for the battery heating in consideration of different operationtemperatures has been extended by a full automatic generationof the pushing schedules by following all actual operatingconditions. The performance of the oven machines comes ever closerto man less operation.
An improved gas-treatment module allows for economic optimizationof the process with regard to the market situation for the differentby-products and consumables.

To maximize furnace campaigns and to minimize production downtimesthrough short lining times, the entire integral blast furnacearea, including the auxiliary units, has to be theoretically partitioned.The evolution of measures for extending furnace life is in conjunctionwith the investigation and understanding of the in some respectsvery complicated wear mechanisms and their causes. Of mostimportance are the constructional, material and process engineeringmeasures to reduce wear and the measuring instrumentation forearly detection and progress monitoring of wear.

The application of mathematical process models for BOF convertersis state-of-the-art for nearly all plants around the world. Such anautomation system may end up in a black box that is not maintainableany more and cannot be adapted to new requirements. Someprinciple experiences and examples from EKO Stahl are presentedto avoid such developments.

A new technique is presented to recycle ladle slag within the electricarc furnace through the injection system. The dilution of the chemicalspecies contained in the slag and their combination with the speciesfeaturing the EAF slag afford a double advantage: the final slagis structured by chemical species that do not lead to the formationof powders and better stabilize the foaming slag. The industrialresults are analyzed on the basis of the chemical species identificationsupported by thermodynamic modelling.

Previous experience achieved with two of the leading systems,namely the VAIron closed-loop expert system of Siemens VAI MetalsTechnologies and the VAIF blast furnace expert system are describedfor several installations. The advantages of both systems havesince been combined into an advanced, state-of-the-art systemreferred to as VAIron–The Next Generation. This paper outlines thestructure and highlights of this new expert system.

The studies developed at CST sinter plant in order to point out any factor that may have an effect on plume visibility are reported. Specific software and indexes have been developed. The approach included a retrospective analysis followed by further industrial tests at the sinter plant with different material input (fuels and raw materials). The results are discussed with reference to potential effects on the plume visibility. Further steps are considered to progress the stack plume project.

The Business Intelligence (BI) aims at providing the operational, tacticand strategic levels with information in order to support managersand specialists through the practice of analysis and decisionmaking. The results of the project pertaining to the steel makingplant are reported.

Two complementary techniques are mainly used for the detectionand characterisation of the inclusions populations present in thesteel bars in a large range of sizes: from 1 μm to 1 mm: the automaticscanning electron microscope associated with image analysisand the 80 MHz ultrasonic inspection. The emphasis has been puton the composition of the inclusions whose size is above the criticalsize (10 - 20 μm) for long life fatigue. The mechanism of formation ofthese harmful inclusions is determined through the process with thehelp of thermodynamics models. This approach makes it possible toimprove the process: avoiding slag entrapment upon casting of bearingsteels, adjusting closely the Ca addition to calcium treatedsteels.


To meet the demand for Interstitial Free and Bake Hardening steelgrades for the automotive industry, CST has developed a productionprocess for steels with ultra low carbon (<20 ppm), and low nitrogen(<30 ppm) levels, along with a narrow range of carbon content. Thenew process also ensures a high degree of cleanliness of the CCslabs.

Energy efficiency in BOF process is related to hot metal and scrapratio and thus to production capacity potential and specific CO2emissions. A thermal balance in the fume system, using a selectedmetrology, can be calculated dynamically and provides a valuabletool for investigating the process parameters that are relevant foroptimizing and controlling energy efficiency. The method and firstresults are presented.

The direct relationship between the total oxygen content of the steelor the slag composition and the rate of surface defects on the finalproducts has been clearly established by many previous studies.The paper describes the appropriate process parameters to preventthe re-oxidation of the molten steel and clogging of the submergedentry nozzles, two essential factors to meet the product cleannessrequirements: quantification of re-oxidation, control of re-oxidationby slags, air or refractories, control of Ar injection, mechanisms andways to reduce CC nozzle clogging.

Substituting used tyres for anthracite in the EAF in France and inBelgium is reported. First trials have been carried out in Lorraine in1997 in the frame of a partnership between Usinor (now ArcelorMittal), Michelin and Ademe. The substitution process has beeneventually implemented by LME in cooperation with Aliapur over theyears 2002-2003. Industeel Belgium got started on substitution in2004. To day, both steel plants have achieved stable operation, witha regular load of 8 to 12 kg used tyres per ton of steel, thus allowingsignificant and sustainable savings on anthracite.

Coke production capacity within AM FCWE is not self sufficient forthe total HM production. PCI was started up in 2004 at Bremen BF2and Eisenhüttenstadt BF5, with a ramp up to 180 kg/thm in one year.A working group defined the BF operating conditions leading to stableand efficient operation at high PCI. At Florange BF3 PCI trials at220 kg/thm were successful. At Dunkerque BF4 and Gent BFA andB, the PCI rate exceeds regularly 210 kg/thm.

The development of a pickling process, more effective and appropriatefor the new steel grades, requires a deep and thorough knowledgeof its interaction with the steel surface. The Surface ICP-OEStechnique developed for some years at ARCELOR RESEARCH SA,has permitted to obtain the electrochemical and chemical characterizationof pickling, in real time, up to now on laboratory samples.The principle and the developments of this technique and its transferto pickling are presented. The results obtained in some caseshighlight the potential and the interest of this approach for an improvedcontrol of the pickling process.

A calcium treatment is performed to improve the machinability of Alkilled medium carbon steel grades. Modelling oxides with the softwareCEQCSI makes it possible to adapt the calcium level accordingto the contents in Al, S and O. The stability domain of the targetedoxides is quite narrow and highly dependent on both temperatureand composition; thus the industrial practice turns out to be difficult.This is confirmed by the analyses of inclusions in some Ca-treatedheats of ArcelorMittal Gandrange. However, their machinability propertieswere found to be 20 to 30% higher than those of the standardgrade.

Key past pilot plant developments in steelmaking and continuous casting are reviewed. The enhanced facility at Teesside Technology Centre is outlined. This comprises an EAF which can tap up to 6.9 t, a combined LAF/tank degasser, vertical with bending caster and ingot casting facilities. The equipment and early commissioning during 2006 are described.

The use of chemical energy in the EAF has increased significantly inrecent years, both for enhancing productivity and reducing electricityconsumption. However, these tools are operated following pre-setpatterns, without any feedback information from the process. Thisleads both to non-optimized operations and to occasional blowbackproblems, resulting in damages to burners, lances, watercooledpanels and refractory lining.
CRM has developed an on-line “distance-to-scrap” measurementtechnique that can be fitted inside annular burners. This measurementallows monitoring the melting of scrap in front of each burner,and thus detecting blow-back occurrences before any damage iscreated. This sensor was successfully tested in the Esch-Belval steelplant of ArcelorMittal Profil Luxembourg. Industrial implementation isunder way.