Why is adding more lime to the BOF a problem when trying to reduce Phosphorous?
Basicity is an important factor in reduction of phosphorous in the BOF. However, the increasing amount of lime usage will increase the basicity to a point that without any fluxing agents present the slag will become crusty and will not mix with the steel to promote phosphorous removal in the steel. Silicon content of the metal provides the fluxing of the lime since FeO is extremely low in BOF slags as compared to EAF slags. Alternate materials could be used to lower the basicity ratio so that a creamy slag can react during mixing for phosphorous removal.
