Separate Recovery of Iron and Phosphorus from BOF Slags by Using Tin

Abstract

The present study was carried out to search for the possibility of the separate recovery of iron and phosphorus as gas from BOF slag by using graphite crucible or graphite powder with the presence of tin bath, which is considered to enhance the activity of phosphorus in iron reduced from slag or not to absorb the phosphorus vapor readily.
When the slag was reduced by graphite crucible, being in contact wtih tin bath, the phosphorus reduced from slag was carried away by CO explosively generated on the reduction of iron oxide. When graphite powder was used as reductant instead, 78% of phosphorus was removed from slag, only 3% of which was absorbed into the tin bath and the rest left the system as gas. The extent of gaseous dephosphorization was observed to depend on the mode of contact between slag and reductant as well as the amount of the latter.