Abstract: Both a method and apparatus for producing molten steel are provided wherein ferrous materials rich in carbonaceous materials are fused in a first vessel of a single electric furnace having separate first and second vessels. The carbonized molten metal thus obtained is then pretreated in a separate pretreatment facility to remove contaminants and the pretreated molten metal is then decarburized in the second vessel of the electric furnace. The decarburization of the pretreated metal in the second vessel of the furnace avoids reintroducing contaminants into the steel by avoiding contact between the pretreated metal and the slag produced when the initial carbonaceous materials are fused. Preferably, the first and second vessels are two vessels of a single electric furnace having a single electric power source.

Abstract: The tuyere comprises a substantially cylindrical or slightly convergent frusto-conical downstream part, and a divergent frusto-conical upstream part; the plasma torch is placed co-axially to the tuyere at the inlet to the upstream part thereof; the solid materials injection nozzle issues at an angle into the upstream part of the tuyere and the angle of taper of the upstream part of the tuyere substantially corresponds to the angle of natural expansion of the plasma jet, so that said materials are carried with the plasma jet and that part of them are provided onto the inner wall of the tuyere.

Abstract: The invention relates to a device for injecting pulverulent material, such as coal, into a blast furnace. The device includes a hot blast tuyere issuing into the blast furnace, a nozzle fixed against said tuyere and co-axial thereto for bringing the hot blast, a branch connection produced obliquely on the nozzle and directed towards the tuyere, and an injection pipe traversing the branch connection to issue into the tuyere. According to the invention, the injection pipe is substantially an arc of circle, the convexity of which is directed towards the axis of the nozzle and of the tuyere. The radius of curvature is at least equal to one hundred times its inner diameter.