上吹転炉における脱燐平衡 : Chipman の平衡の適用

概要

論文の詳細を見る
The authors applied the dephosphorization equilibrium formula reported by Chipman to mostly the final slag and metal samples of the 3 ton experimental LD converter. The results obtained were as follows. (1) The observed values of K_p, dephosphorization constant calculated from oxygen in metal, were in fairly good accordance with Chipman's equilibrium values, while the values of K_p, dephosphorization constant calculated from (FeO) in slag showed a definite descre-pancy from Chipman's equilibrium values. Furthermore the descrepancy increased almost proportionally with the increase of (FeO)% or T.Fe% in slag. Experessing this descrepancy as ⊿log K_p′(=log K_<p′(chip)>-log K_<p′(obs)> the ahthors obtained the following relations statistically. ⊿log K_p′=0.07 T.Fe%-0.80……(1) or ⊿log K_p′=4.99N_<FeO>-0.95……(2) (2) During the final stage of the blow, the oxygen in bath did not increase proportionally with (FeO) in slag and at the end of the blow the oxygen in bath was generally lower than the value predicted from the distribution equilibrium of oxygen between metal and slag. Therefore less effect of "after-blow" to dephosphorization could be expected compared to the bottom blown converter. (3) In the final slag of the converter there existed somewhat a definite relation between N_<CaO>′ and N_<FeO> according to the operation condition such as the amount of lime charged, [Si]% of pig iron, pig ratio, etc. N_<CaO>′tended to decrease with the increase of N_<FeO> because of the dilution effect of (FeO). For the slag they studied, the following relation was obtained. N_<CaO>′=-0.74N_<FeO>+0.72……(3) (4) The relation between phosphorus-distribution ratio, log N_<Ca_4P_2O_9>/[%P]^2 and N_<FeO> was calculated as follows. log K_<p′(obs)>=log K_<p′(chip)>-⊿log K_<p′>……(4) log K_<p′(chip)>=40067/T-15.06……(5) from Eq. (2), (5) and (4) log K_<p′(obs)>=log N_<Ca_4P_2O_9>/[%P]^2(N_<FeO>)^5(N_<CaO′>)^4_<(obs)>=40067/T-15.06-4.99N_<FeO>-0.95……(6) from Eq. (3) and (6) log N_<Ca_4P_2O_9>/[%P]^2_<(obs)>=4.0067/T-4.99N_<FeO>+5 log N_<FeO>+4 log (-0.74N_<FeO>+0.72)-14.11……(7) With the increase of N_<FeO> the value of logN_<Ca_4P_2O_9>/[%P]^2_<(obs)> increased to a maximum value at about N_<FeO>=0.3 but with the further increase of N_<FeO> it began to decrease. This relation is very interesting when they consider the practical phenomenon that during "after-blow" dephosphorization is not so much improved in spite of the rapid increase of (FeO) content in slag.
社団法人日本鉄鋼協会の論文
1958-07-01

上吹転炉における脱燐平衡 : Chipman の平衡の適用

スポンサーリンク

概要

著者

関連論文

スポンサーリンク