Desulphurising molten blast furnace iron - using oxygen lance and soda added in two stages for efficient sulphur removal

摘要

Crude iron is desulphurised by refining with an immersed oxygen lance, where the iron has min. saturation in MnS of 0.6, and desulphurisation occurs in two stages; (a) the molten bath of iron is sub-saturated with MnS; and a waiting time of 15 minutes is used before stage (b). Pref. 60% of the desulphurising agent is injected in stage (a), in which the bath is guided to a sub-saturation value in Mns of b=0.6 min. In using an oxygen lance with the addn. of soda as the desulphurising agent, very low final sulphur contents can be obtd. in iron made in a blast furnace.