METHOD AND DEVICE FOR PRODUCING PIG-IRON BASED STAINLESS STEEL WITHOUT USING A SUPPLY OF ELECTRICAL ENERGY

摘要

Abstract The aim of the invention is to produce stainless steel for all stainless steel products both in the austenitic and the ferrites range, based on liquid pig-iron and Farce solids, without using a supply of electrical energy. According to the invention, the liquid pig-iron, after being pre-treated in a blast furnace (1), is subjected to a DDD treatment (dephosphorisation, desiliconisation and desulphuration), is heated, finished or alloyed and deoxidated. The quantity of slag-free liquid pig-iron that has been pre-treated in the blast furnace (1) is separated and introduced into two classic twin AOD-L converters (2, 3), where the required chemical process steps (of the DDD treatment and of the heating, decarburisation and alloying stages) take place in parallel contrary processes using autogenously chemical energy, the DDD treatment being carried out first in the first twin AOD-L converter (2) and the decarburisation being carried out first in the second twin AOD-L converter (3).