CaO-SiO2-FeO 系スラグによる溶鉄の脱りん速度
1984 年 70 巻 14 号 p. 1681-1688
詳細
1984 年 70 巻 14 号 p. 1681-1688
The rate of dephosphorization of liquid iron by the slag of CaO-SiO2-FeO system was investigated at temperatures of 1 570, 1 610 and 1 650°C.
The rate of dephosphorization was analysed as a first order reaction equation. On the basis of the discussion on the effect of slag composition on the rate of dephosphorization, it was found that the reaction-rate constant was expressed as function of CaO and FeO content in the slag and temperature as follow:
logk=1.67log(%CaO)+1.90 log(%FeO)-5 620/T-5.057
It was obvious from this expression that the optimum composition of slag for the rate of dephosphorization is 47% CaO-53% FeO.
The discussion was made on the rate determining step of the reaction, and it was considered that the diffusion of phosphorus from slag-liquid iron interface to slag phase controlls the rate of reaction. On the basis of the discussion on the rate determining step, the value of D(P)/δ was obtained to be
0.1-7.0×10-4cm/s(1 570-1 650°C).
