抄録
In the reduction of BOF slag with carbon, for the purpose of its reclamation, not only P2O5 but also FeO are reduced to form Fe-P-C alloy from which phosphorus should be removed later for the utilization of byproducts. According to this concept, firstly, experiment has been made of the reduction of synthetic slags and BOF slag (I), secondly, the evaporation of phosphorus (the species is P2) from the alloy obtained at the first stage, adding silicon in order to increase the activity of phosphorus by use of levitation technique (II).
The results of two type of experiments are summarized as follows:
A large amount of iron oxide is reduced until the reduction of P2O5 starts (I-1).
The dephosphorization of iron free slags by carbon is controlled by the chemical reaction (I-2).
The vacuum treatment significantly enhances the dephosphorization of Fe-Si-P alloys and the minimum content of phosphorus, 0.005%, is obtained in 7 minutes (II-1).
The evaporation rate of phosphorus from Fe-Si-P alloys increases with increasing silicon content and the rate determing step is the transport of P2 in gas phase with some exceptions (II-2).
