From 1998 to 1999, an extremely intensive dioxin measuring campaign has been performed at the sinterplants of Sidmar. More than 500 measurements have been made. Several hypotheses and adsorbents have been tested for the reduction of the dioxins. Process control improvements and the use of burnt lime then allowed reducing the dioxin emissions by 85 % . For a further decrease, it was decided to build an industrial coal injection installation at the sinterplants. The present reduction of the dioxin emissions is more than 95 % and will reach 97 % in 2001.

Technical improvement on clean steel in the No.3 steel plant at Wisco, China Z. Yu, W. Zheng, X. Wang, Y. Zou In recent years, a series of measures have been taken to improve the cleanliness of the steel produced in the steel plant No.3 of Wisco. The content of impurities like C, N, H, S and total O is accurately controlled. The amount and nature of non-metallic inclusions can be adjusted and their shape modified. Results obtained in the case of IF steel and linepipe grades are presented.

In March 2000, a new compact steelmaking plant of Suez Steel (Adabia, Egypt), erected by VOEST-ALPINE Industrieanlagenbau (VAI), has successfully been started up. With a Finger Shaft type electric arc furnace (FUCHS system), a ladle furnace and a 5-strand caster, this highly modern plant has a capacity of 600,000 t/year of structural steel billets. Since the start up, new production records are continuously established.

In order to extend the RH lower vessel campaign life and to recycle used retractories, MgO-C bricks were applied for the RH lower vessel. As a result, the campaign life of the lower vessel has been extended by approximately 15 % , compared with magnesia- chromite bricks normally used. It was further ensured that it was possible to refine ultra-low carbon steel under these conditions.

When argon gas is injected into the caster moulds, the similarity between water models and actual casting conditions comes into question. This is why LTV decided to investigate new technologies. The paper presents these technologies and discusses the programme results. PIV is a powerful laser-based technology that was used on the LTV 0.4 and full-scale water models to determine water velocities. MFC sensors are magnetic sensors that were installed on the LTV Cleveland-East 2-strand slab caster to measure actual liquid steel velocities. In addition, nails boards, X-ray and SEM analyses were extensively used to determine molten slag layer thickness profiles during casting, gas bubbles/pinholes location and steel defect composition, respectively.

During 1999 and 2000, the six lines of the continuous billet casting machine of ISPAT Unimétal at Gandrange (France) have been equipped with the DIAMOLD moulds developed by VOEST- ALPINE Industrieanlagenbau (VAI). This transformation required no constructional change of the machine and represented only a minimum investment. The new mould technology allows to cast at very high speeds (above 3 m/min) and to comply with all quality requirements for a wide range of steel grades.

In May 1998, Muroran Works installed a near-net shape casting and compact high reduction (NCR) process in its steelmaking plant. The No.3 continuous casting machine was rearranged to cast middle cross section blooms, and a reheating furnace and a 2-passes high reduction breakdown mill were newly equipped. No.3 CCM casts square 220 mm mould size blooms and the breakdown mill reduces their cross section to square 162 mm. This combined process improved the quality of the cast billets and achieved high productivity.

Improvements have been made to slab, bloom, billet and thin slab caster secondary cooling systems giving better control of strand surface temperature and quality. This has been achieved by a combination of laboratory-based tests of spray characteristics and heat transfer coefficient (htc), innovative mathematical modelling and detailed on-plant measurements of temperatures and spray conditions.

Kawasaki Steel Corporation carried out a modernization project at the Chiba works No.2 continuous annealing line by linking the CAL with the existing skinpass mill and newly constructed facilities in the downstream area. Because the No.2 CAL and the skinpass mill are arranged in parallel, Kawasaki developed the world steel industry's first non-contact air floatation type strip turning device, called the "Helical turner".

To control the generation of dust in a steelmaking reactor, it is necessary to understand the underlying physical mechanisms. An experimental device has been developed to study the main emission mechanism, i.e. the projections from bursting bubbles. We visualized the burst on liquid steel and quantified the subsequent emission. The chemical evolution inside the fume exhaust system is simulated by thermodynamic calculations : the key parameters for controlling dust mineralogy are the Fe/Zn ratio, the oxygen activity (p$_{{\rm CO_2}}$/p$_{{\rm CO}}$) and the temperature evolution.

The applications of vacuum treatments for coating metals are recalled. The surface preparation, which is essential for any efficient deposition process, is first examined. The main vacuum coating techniques are described in detail, with the emphasis on technologies actually used in tndustry, with their advantages and disadvantages. Examples of the industrial application of this process are given and their economic importance discussed.