EFFECT OF STIRRING ENERGY AND RATE OF OXYGEN-SUPPLY ON THE RATE OF HOT METAL DEPHOSPHORIZATION

Study was made on desiliconization and dephosphorization reaction kine tics at various size equipments. Coupled reaction model was employed t o analyse rate determining step of desiliconization and dephosphorizat ion reaction. In the case of desiliconization reaction, mass transfer process in hot metal phase determines the reaction rate. On the other hand, dephosphorization rate is controlled by mass transfer process bo th in hot metal and slag phase. Mass-transfer coefficient in hot metal phase k(m), proportionally increased with 0.7 power of parameter epsi lon/d(C)(2), independently on the equipment size, where, epsilon, d(C) is stirring energy of hot metal and the diameter of the vessel, respe ctively. Apparent rate constant of dephosphorization k(p)(')=In([%P](i )/[%P](f))/t(f) increased with increase in stirring energy epsilon' an d rate of oxygen supply V-O2 under the optimum relationship between ep silon' and V-O2 which was predicted by model calculations, where [%P]( i) and [%P](I) is initial and final phosphorus content and rr, refinin g time. This optimum relationship was expressed as the empirical relat ion, epsilon' = 1.51 V-O2(2) + 3.31 V-O2 under the condition of this s tudy.