PROCESS FOR PRODUCING MOLTEN STAINLESS STEEL.

摘要

A process for producing molten stainless steel by continuously subjecting Cr materials such as Cr ores or Cr pellets to melt reduction and decarbonization in one vessel at high treating speeds, which comprises, in the melt reduction, blowing an inert gas or the like through a bottom-blown tuyere to form projections on the molten metal surface and blowing an inert gas or the like against the projections through a side-blown tuyere to diffuse the molten metal into a Cr material-floating zone in the slag for accelerating the reduction of the Cr material with C contained in the molten metal and, on the other hand, blowing O2 for decarbonization into the molten metal through a top-blown lance and O2 for secondary combustion into the slag to form a secondary combustion zone mainly in the slag, and vigorously stirring the slag by the side-blown gas to give a heat produced by the secondary combustion to the Cr ores with high efficiency while keeping a second combustion ratio at 0.3 or more for assuring high secondary combustion and, after the melt reduction, discharching the slag and top-blowing O2 for decarbonization diluted with an inert gas and blowing an inert gas through the bottom-blown tuyere to vigorously stir the molten metal.