The ULCOS blast furnace process aims at reducing theCO2 emission of the blast furnace by 50% in two steps:
Decrease of carbon consumption by recyclingmost of the top gas after CO2 removal, which requiresoperating the blast furnace with pure oxygen;
Underground storage of CO2.
The first stage is essential to demonstrate the feasibility of thisnew process. It has been tested over a 6 week campaign atthe LKAB experimental BF in Luleå. The facility was adaptedspecifically for the trials (including the erection of a VPSAplant). Different operating conditions were investigated.In conclusion, and taking into account underground storage,the CO2 emission at the blast furnace was reduced by upto 76%. For the steelmaking plant, this should result in anet CO2-savings of 65% at the level of the hot rolled coil.

The role of slag in ladle metallurgy and tundish is discussedstarting from thermodynamic considerations of equilibrium/non-equilibrium states between slag and steel. Some interesting steel grades with different deoxidation philosophy are chosen as examples. Physical aspects concerning therole of stirring, slag properties e.g. viscosity and interfacialtension are examined as well. The title question is discussedand evaluated based on theoretical considerations andcomparison with modelling experiences and industrial data.

The efficiency of dephosphorisation is governed by thethermodynamic behaviour of phosphorus and oxygen in moltenmetal, and P2O5 and FeO in slag. The equilibrium distributionof phosphorus and oxygen, for a wide range of chemicalcompositions simulating the evolution of slag composition duringa typical BOF blow, has been experimentally determined. Amathematical model for estimation of the activity coefficients, asa function of the chemical composition, was also attempted.

The paper aims at giving an overview of galvanizing reactionof steel sheets, highlighting how the solid Fe - liquid Znsystem tends to keep the liquid Zn phase at thermodynamicequilibrium. Reactions occurring with Al free, intermediate Al bearing(typical of GA production), and higher Al bearing (typicalfor GI production) Zn bath are detailed.

Strip surface state before zinc bath immersion is linked totemperature homogeneity and gas atmosphere compositionin each furnace section. Many different gas metal reactionsoccur in the furnace that may improve the strip heatingrate or introduce surface defects, depending on theirlocalization. Gas flow models of the preheating-heating sections with hightemperature variations have been developed. They pointout temperature gradients and the competition betweennatural convection and forced convection. A model for gasexchanges between all furnace sections has been built andvalidated by gas tracing trials on industrial lines. The effect of line process parameters such as line speed,strip format and gas injection condition in all furnacessections is reported.

GI coatings are covered by a very thin aluminum layerthat precipitates after wiping. Anisotropic growing of zinccrystals during solidification induces a strong basal texturein GI coatings. Skin-pass induced changes in GI coatingsurface chemistry, crystallography and reactivity have beenassessed. Local coating analyses have been performed (XPS,TOF-SIMS) in order to describe local effects of roughnessindentation during skin-pass on coating characteristics. A laboratory bi-crushing device supported by XRD and EBSDhas been used to analyze the aluminum oxide behaviourduring deformation and ageing. Reactivity of such surfaceshas been tested using fatty acids.