1983 Volume 69 Issue 15 Pages 1841-1848
A new process for the hot metal dephosphorization is examined. It is done in the 200 t hot metal ladle, soda ash being top charged, oxygen gas being top blown and nitrogen gas being injected through a submerged lance. Dephosphorization reaction is analyzed in terms of its reaction equilibrium and stirring intensity or energy involved.
Equation for the dephosphorization equilibrium is established by the extrapolation of the laboratory data at 1 600°C :
logK=(P2O5)/[P]2=1873/T[9.49+8.41log{(CaO)+2.32(Na2O)} - 4.78log(SiO2)] + 5logao+0.26[C] +
36 850/T-25.32
This equation is found to well describe the hot metal dephosphorization all through the treatment. Thus, the reaction is found to proceed very close to the equilibrium.
The effect of the oxygen blow and the stirring upon the dephosphorization is clearly demonstrated. The optimum stirring energy is found to exist for the maximum dephosphorization attainment: between 0.6 to 1.5 MJ/t.
