During the production of stainless steel in an electric arc furnace a significant part of the charged chromium is transferred to the slag. With the new technology of aluminium injection, chromium is recovered from the slag, thus alloying components and costs are saved. Typical mechanically processed Al granules used for the EAF slag injection (grain size: approx. 1–2 mm) are displayed. Due to the exothermic reduction reaction a release of heat is additionally achieved leading to a decreased specific consumption of electric energy and increased productivity. The new process was tested successfully under operational conditions at BGH Edelstahl Siegen GmbH in collaboration with VDEh-Betriebsforschungsinstitut GmbH, and afterwards profitably realized by BGH as a standard procedure at its running EAF. Results of operational trials undertaken at mobile BFI injection device are presented with regard to the average chromium oxide mass fraction of the final EAF slag and the associated chromium yield (ferritic and austenitic steels). Energy balance for these steels is compared for normal operational practice and aluminium injection. Typical process diagram for the stainless steel production at BGH including the new implemented aluminium injection has been constructed. Development of stainless steel production in Europe from 1996 to 2006 is analyzed and chemical composition of the different stainless steel groups is shown.
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