METHOD FOR CONTROLLING FLOW RATE OF OXYGEN FOR REFINING FOR METALLURGICAL REFINING FURNACE

PURPOSE:To enable converter blowing with an always optimum oxygen flow rate pattern and to form a molten steel having the components and temp. coinciding with target values at the end point of blowing by controlling the amt. of the oxygen to be blown so as to attain the oxygen supply rate set for each of steel kinds at the time of refining the steel by oxygen blowing in the converter. CONSTITUTION:Gaseous O2 is blown from an oxygen top blowing lance to the molten iron 10 in the converter 11 and the molten iron is subjected to the oxidation reaction consisting mainly of decarburization and is refined to the molten steel by desiliconization, dephosphorization and decarburization reaction. The pattern for the amt. O1 of the oxygen necessary for oxidation decarburization of the C in the raw material molten iron, the amt. O2 of the oxygen necessary for oxidation of Si, Fe, Mn, and P which vary with the presence or absence and the limit of prerefining, etc., the amts. O3, O4, O5 of the oxygen formed from raw materials such as Mn ore, Fe ore, and scale, the amt. O6 of the oxygen necessary for oxidation of a raw material carbonaceous material, and the amt. of the oxygen necessary for blowing are expressed by O0=O1+O2-O3-O4-O5+O6 and is set to an input device 18 according to the steel kinds to be produced (mainly the change of the steel kind by the content of C). A flow rate valve 15 provided to an oxygen supply pipe 13 is regulated via a control device 17 by such pattern.