Transport rate of gaseous phosphorus into solid iron under reducing atmosphere was observed by a gravimetric procedure to obtain fundamental data to discuss transport mechanism of phosphorus into reduced iron in a blast furnace. A kind of killed and rolled steel sheet and non worked electrolytic iron sheet were used as samples. Partial pressure of phosphorus vapor was controlled by using equilibrium relation between P(P2), C(a3) (PO4)2, SiO2, C, CaSiO3 and CO. Phosphorus partial pressure and temperature were every one order between 4 x 10(-6) and 4 x 10(-2) atm, and every 50-degrees-C between 900 and 1 050-degrees-C, respectively. Experimental results are as follows: (1) Transport rate obeyed a parabolic rate law. (2) Relations between the rate constants of the parabolic rate law, k, the phosphorus partial pressure, P(P2), and the temperature, T, are as follows: In the case of killed steel, log k = 0.14 log P(P2) + 5.68 - 15.6 x 10(3)/T In the case of the electrolytic iron, log k = 0.14 log P(P2) + 4.94 - 15.6 x 10(3) / T (3) Reaction product on a surface of solid iron was Fe2P.
