Low slag volumes favour high productivities. In the case of Sidmar, the burden consists of more than 90 % sinter. The iron content of the sinter has been optimized. Slag volume is thus reduced and productivity between 65-70 tHM/m2.24h is achieved. At high pulverized coal injection rates, the residence time of the coke increases substantially and a higher degree of degradation is to be expected. Therefore, a careful monitoring of the coke and sinter quality is of prime importance. This paper describes the coke and sinter quality used in the Sidmar blast furnaces to control permeability of the furnace with long term PCI rates of 180 kg/tHM and coke rates around 300 kg/tHM. A global quality index has been defined which is well correlated with the blast furnace productivity. Sidmar believes that the quality requirements of the burden can directly be linked with the requested productivity and that good operational practices are necessary for optimization of that productivity.

Companhia Siderurgica de Tubarão (CST) No. 1 blast furnace has been in continuous operation for 21 years, accomplishing a high operational performance with high productivity and low fuel consumption. Seeking its biggest challenge of 18,500 t/m3-IV of productivity, several jobs have been developed in order to extend the furnace campaign until 2008. This paper shows the results of these activities and proposes a different concept of hearth wear.

Salzgitter AG has a crude steel production capacity of more than 8 million tons. Its subsidiary Salzgitter Flachstahl GmbH produces hot strip, thin sheets and surface finished products as well as input stock for heavy plates and sectional steel. In February 2003, Salzgitter Flachstahl GmbH awarded a contract to SMS Demag AG for the supply of a single-strand slab caster including the building portion and all ancillary equipment under SMS leadership. A range of as many as 400 steel grades is cast on the two already existing bow-type continuous casters. The new caster has enhanced the grade range by adding in particular phosphor-alloyed and high-tensile steel grades, including HIC resistant as well as IF and C steel. This caster had to be designed in such a way as to be suitable for taking over production of one of the two existing casters in the longer term. Other goals of constructing a new, third slab caster were to increase the annual production rate of all three casters to a total of 4.7 million tons, to cut production costs, to improve the product quality and to safeguard slab production during the standstill and scheduled maintenance of one of the existing casters.

An Electromagnetic Brake (EMBR) makes it possible to increase the casting speed while maintaining or even improving the product quality. For conventional slabs, the FC mould is most appropriate while for thin slabs, the ruler type EMBR is the preferred solution. The FC mould features two independently controlled static magnetic fields, one at meniscus level and another at the bottom of the mould. The upper field controls the speed flow at meniscus to prevent mould powder entrapments and the lower field reduces the penetration of the steel jets from the casting nozzle, to facilitate flotation of inclusions. The FC mould is the only equipment capable of controlling these parameters independently. It affords effective solutions to reduce pinholes, cracks and surface or subsurface inclusions. A new closed loop control of the FC mould, the EM Control, has also been developed, based upon the input of two meniscus level signals that simulate the meniscus speed. Through 3D transient modelling of the caster performance, temperatures, steel speed, meniscus level are made available. The two static fields are then adapted on-line to achieve both low penetration and a constant meniscus speed.

This article describes an innovating measuring device to continuously assess the powder coverage on the whole surface of the mould in a continuous casting process. The measurement is based on the use of a thermal imager device moved along the mould. With adequate translation and rotation of the camera, it is possible to view up to 72 % of the surface of the mould. A dedicated program for images acquisition and processing displays coloured maps of the mould on which areas with poor powder coverage are clearly highlighted. With this technique, the control of the powder addition in a closed loop way, by using the analysis of the image, is possible.

Through process control, from BOF down to finishing lines, has been developed and implemented. It features real time on line control of defects, risk assessment and the prediction of the mechanical properties. This innovative process control makes it possible to reduce drastically the standard work load of the Metallurgy and Quality Department. The experienced staff can then be appointed new ambitious objectives towards the industrial excellence: “The right product at the right time for the right cost”, “Meeting customer needs” and “Respect the firm's economic objectives”. To achieve this, business organization must be adapted. Key factors are intelligent listening to the final customer needs and process route optimization from the BOF to our customer facilities, paying particular attention to synergies between the hot and the cold mills.

The Integrated Pollution Prevention and Control Directive (IPPC) published in the EU in 1996 is presented within an approach based on source-targeted measures. The Directive implementation is based on the granting of permits and it introduces new concepts like Best Available Technique (BAT), Best Reference Document (BREF) and Level Playing Field (LPF). The consequences for the EU steel industry are discussed.

A physical limit to the galvanizing speed exists over which the liquid film explodes completely and prevents any further wiping. This limit is presently estimated around 180-200 m/min. A dimensionless approach including the Weber and Reynolds numbers is proposed to be able to predict the occurrence of the phenomenon. Practically it comes out that nozzles tilted by 30° down to the pot can pushback the limit by 30 %. A maximal line speed around 220 m/min could thus be reached.