Abstract: A method for controlling a flow rate of gas for prereducing ore comprises the steps of prereducing ore in a prereduction furnace having a fluidized bed with a gas generated in a smelting reduction furnace and controlling a pressure of gas generated in the smelting reduction furnace and introduced into the prereduction furnace, thereby controlling the actual flow rate of gas introduced into the prereduction furnace. An apparatus for controlling a flow rate of gas for prereducing ore comprises a flow passage for introducing gas generated in a smelting reduction furnace into a prereduction furnace and a gas pressure control valve positioned in the flow passage.

Abstract: An apparatus for a smelting reduction of iron ore comprising a preheat and prereduction furnace which preheats and prereduces iron ore, a smelting reduction furance into which said preheated and prereduced iron ore, carbonaceous material and fluxes are charged and in which said preheated and prereduced iron ore are smelted and reduced, a top blow oxygen lance having decarburizing nozzles and post-combustion nozzles and blowing oxygen into said smelting reduction furance, and at least one side tuyere placed at a side wall of the smelting reduction furnace and at least one bottom tuyere placed at a bottom of the smelting reduction furnace through which a stirring gas is respectively blown so that at least a part of said stirring gas introduced through said at least one side tuyere hits a swollen portion of the molten metal by said stirring gas introduced through said at least one bottom tuyere.

Abstract: A method for smelting reduction of iron ore comprises the steps of: preheating and prereducing iron ore; charging said preheated and prereduced iron ore, carbonaceous material and flux into a smelting reduction furnace; blowing oxygen gas through a top blow oxygen lance having decarburizing nozzles and post-combustion nozzles into said smelting reduction furnace, an end of said top blow oxygen lance being arranged between an upper side level of a slag layer and a lower side level of said slag layer; blowing a stirring gas through at least one side tuyere placed in side wall of said smelting furnace and at least one bottom tuyer placed in bottom wall of said reduction furnace so that at least part of said stirring gas introduced through at least one said side tuyere hits a swollen portion of the molten metal by said stirring gas introduced through at least one said bottom tuyere; and controlling a flow rate of said oxygen gas and said stirring gas blown in said smelting reduction furnace so that an OD of infur

Abstract: An apparatus for smelting reduction comprising a preheat and prereduction furnace for preheating and prereducing iron ores; a smelting reduction furnace into which iron ores, carbonaceous material and fluxing material are charged and in which the iron ores are smelted and reduced; a top-blow oxygen lance through which oxygen gas is blown into the smelting reduction furnace, having decarbonizing nozzles and post combustion nozzles; and the smelting reduction furnace having bottom and side tuyeres built respectively in a side wall and a bottom thereof.

Abstract: A method for smelting and reducing iron ores comprises the steps of: the step of preheating and prereducing iron ores; the step of charging the preheated and prereduced iron ores into a smelting reduction furnace; the step of charging carbonaceous material and fluxing material into the smelting reduction furnace; the step of blowing in oxygen gas into the smelting reduction furnace through a top-blow oxygen lance having decarbonizing nozzles and post combustion nozzles; and the step of blowing in stirring gas through side and bottom tuyeres set respectively in a side wall and a bottom of the smelting reduction furnace.

Abstract: A method for manufacturing molten steel wherein iron ore and coal are continuously supplied onto molten metal containing carbon of 1% or less while blowing oxygen gas is being introduced onto the molten metal through a lance. Simultaneously with this operation, stirring gas is being introduced into the molten metal at a rate of 0.05 to 0.5 Nm.sup.3 /min/ton of molten metal through a tuyere. The slag and the molten steel produced, is continuously or periodically discharged.

Abstract: At least one lance is substantially vertically arranged above a hot-metal runner of a blast furnace so that the lowermost end of the lance is spaced apart by a prescribed distance from the surface of molten pig iron flowing through the hot-metal runner. A granular chemical composition adjusting agent for adjusting the chemical composition of molten pig iron is blown, through the lance, into molten pig iron by means of a carrier gas to adjust the chemical composition of molten pig iron so as to satisfy the following two equations:0.5H.ltoreq.H.sub.p <H (1)H.sub.p =M.multidot.G.multidot.exp(-r)/(D+0.02H.sub.L).sup.2 (2)In equations (1) and (2):H: depth of molten pig iron in the hot-metal runner (mm),H.sub.p : penetration depth of the granular chemical composition adjusting agent into molten pig iron in the hot-metal runner (mm),M: flow rate of the granular chemical composition adjusting agent (kg/minute),G: flow rate of the carrier gas (Nm.sup.

Abstract: A method of regenerating molten slag remaining in a furnace or converter or the like after tapping of steel, by adding solid carbon and flux to the slag, blowing oxygen into the slag, heating to a temperature of more than 1500.degree. C and agitating. The regenerated slag can be controlled in composition to be most suitable for such ultimate uses as lime, cement, etc.

Abstract: In a steel making process with an oxygen top-blown converter when a certain inclining angle (.theta.) is given within a range of 0<.theta..ltoreq.15.degree. to normal axis of an oxygen blow lance being supported at an upper portion of the lance and a certain number of rotation (.nu.) is given within the range of 0<.nu..ltoreq.15 rpm to the lance, the blow of oxygen is possible to be properly used as the refining reactions are advanced without any delay of slagging reaction and any stagnation of non-slagging lime during blowing.