Refining pig iron in a converter - by using lime and oxygen

摘要

Addition to 2149023 discloses a one step oxygen refining procedure for P rich pig iron in the converter by using a multihole lance for feeding lime, i.e. 80% within the first 5 min., and then pure oxygen to effect acceleration of dephosphorization with a foamy slag. The amt. of lime added can be varied within 60-90% of the total amt. of lime within the first 3-8 min., pref. 5 min. of the refining period at a lance distance of 2.5m. Pure oxygen is then blown at a lance distance of 1m. after which the rest of the lime is blown into the melt. The pig iron has a final P content of 0.03%.