PARE has developed an electrode wear monitoring system. Theyhave implemented such systems at the three electric arc furnaces(two DC, one AC) located in Luxembourg. The goal of these systemsis twofold: first it allows the steelmaker to continuously monitor itsgraphite consumption and relate it to the furnace operating conditions;second it allows a feedback to the electrode suppliers for qualitymonitoring.

Aceralia blast furnace A suffered a 28-days emergency repair inSeptember 2004, due to accelerated wear of the hearth walls andsevere damage of the cast iron staves at the bosh area. Consideringthe shortage of supplies, Aceralia resorted to non conventionalrepair methods in order to prolong the campaign by one year, untilfull relining: small format carbon bricks and carbon ramming massfor the hearth and tapholes and steel staves at the bosh.

A new SSMR process to produce ultra-fine-grained hot strip is introduced,featuring: closely spaced rolling stands, continuous highspeed rolling with moderately large reductions rolling, rapid interpasscooling and rapid finish rolling cooling. An ultra-fine-grained CMnsteel strip (1μm) is obtained with a 700 MPa yield stress. Aproper choice of the work roll diameter and a careful control of thefriction coefficient should make it possible to keep the rolling forceat a level compatible with the design capacity of a conventional rollingmill.

The rotating lance, tested in the CaO-Mg and CaC2-Mg processes,promotes a 20% and 30% increase, respectively, in the desulphurizationrate, a 50% reduction of temperature drop, and a reduction ofmetal splash occurrences. A criterion was developed that takes intoaccount the equipment dimensions and the mass flow rates of gasand desulphurization material, with the objective of transposing theresults obtained at Usiminas steel shop n°1 desulphurization station,to other industrial plants. Furthermore, it allows simulations to bemade with the objective of optimizing the pig iron desulphurizationprocesses that use the above mentioned materials as desulphurizationagents.

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.

The “airtight” technology allows energy savings but hinders directprocess observation inside the vessel and information on the unmeltedscrap volume and on possible skull formation at the furnacewalls. To overcome this difficulty, a new concept is proposed, basedon mounting a camera and an endoscope inside an existing burner.This technique has been first implemented on the 155 tons DC furnacein the PROFILARBED Esch-Belval plant. Typical images of themelting phase are presented. Scrap movement mechanisms in theburner produced cavity have been displayed in real time.Operational benefits combine the appraisal of scrap basket chargingtime and anticipation of abnormal melting behaviour.

As cast CC slabs of microalloyed steels are prone to surface cracking. Precipitation phenomena, initiated during solidification, reduce ductility at high temperature. The size, morphology and distribution of precipitates in as cast semis depend on solidification rate, on secondary cooling, straightening and cooling off the caster. Microsegregation of the microalloying additions to the interdendritic boundaries during solidification increases precipitation temperature. Results are presented concerning the effect of solidification and cooling on precipitates characteristics in semis. The characterization of precipitates is quite satisfactory although it could not be clearly correlated with surface quality.


Flameless oxyfuel combustion used in industrial furnaces gives a uniformtemperature and heat flux distribution along with high availableheat. NOx emissions can be maintained at extremely low levels, meetingthe most demanding environmental regulations. Since 2003 theexperimental results from flameless oxyfuel technology have been provenin industrial installations such as reheating and annealing furnacesas well in ladle preheating stations.

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.

The quality and quantity of steel treated in an RH vessel can beenhanced through the optimization of the metallurgical reactionsoccurring during vacuum treatment and with an improvement in theequipment design and plant layout to reduce production-time losses.The enlargement of the diameter of the snorkel and vesselcontribute to an accelerated reaction rate inside the vessel and to anincrease in the overall productivity of an RH plant. With the introductionof twin-station RH plants in connection with a quick vesselexchangedesign, the loss of production time due to ladle transfer,vessel exchange and snorkel maintenance can be significantly reduced.

A project was started in 2002 to improve the hot metal desulphurisationby ladle treatment, whose underlying mechanism was analyzedby a process model based on fundamentals. This allowed a10% reduction of reagent consumption. To reduce the treatmentcosts, calcium carbide was replaced by lime. Further results indicatethe need to improve the absorption of reaction products into theslag. Lime post injection resulted in lower final sulfur content andimproved slag removal.

Standard EAF operate with a large amount or air ingress (on theorder of 30 000 Nm3 for 150 t of steel). This air is at ambient temperaturethus, the nitrogen content and the non-reactive oxygen areonly heated through the furnace and exit with the fumes at high temperature(1000°C). This brings about significant thermal losses.Reference and airtight trials were carried out with the 6-t EAF ofArcelor Research for assessing the gains related to airtight furnaceoperation.

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.

Strip width necking may be quite significant on cold rolling mills. Tocompensate for this unpredicted phenomenon, hot strips are oftenordered with an over-width with resulting substantial over costs, fortrimming in particular. Based upon numerical simulation supportedby rolling trials, the main factors that effect strip width variation havebeen quantified: edge drop, transverse stress relaxation, thermalcontraction. Potential width actuators to be implemented on industrialcold rolling lines have been identified.

Oxygen usage has played a crucial role in the ongoing EAF processimprovement and has enabled furnace operators to optimize thechemical energy input, reaching unprecedented efficiencies and productivity.This article will present the fundamental principles governingthe design of an optimized chemical energy system throughscrap oxy-cutting and melting, decarburisation, post-combustionand slag foaming. It will be illustrated with industrial results obtainedat the Vallourec Mannesmann Saint-Saulve site, where a PyreJetTM and ALARCTM PC system, using the newly designed DRAGON Panel, has been recently commissioned.

The control of oxygen and fossil fuels injections, taking into accountreal furnace conditions at each step of the melt, is essential for EAFimprovement. Based on near IR Laser- diode spectroscopy, a systemenabling dynamic and continuous CO and CO2 monitoring of EAFfumes during the whole melt for long-term operations has been developed.Several industrial trials are reported, the technology is describedand the results are discussed.

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.

A new method for controlling the BOF process is proposed thatinvolves the use of an original in blow heterogeneous sampler and adedicated laser analytical method. The aim is to deliver a fast andcomprehensive analysis of steel and slag collected by the heterogeneous-samplings. Combined with a metallurgical model, the dataobtained with the heterogeneous samples make it possible to dynamicallyassess the refining progress in order to allow a safe directtapping practice.