In order to improve manganese recovery by smelting reduction of manganese ore during less slag blowing at BOF, the effects of sintered manganese ore on reduction behavior have been studied both in 100kg laboratory scale and in 340t industrial scale tests. Results obtained in this work are summarized as follows. 1) The oxidation of [Mn] during addition of manganese ore is suppressed by using sintered manganese ore, because the active oxygen in manganese ore can be decreased to one third by sintering. 2) Addition of CaO to sinter is very effective for increasing the reduction rate of (MnO). Especially, it is most effective when CaO/SiO2 of sinter is more than 3. 3) Using the sinter with CaO/SiO2 of 3.05, manganese recovery in industrial converter can be increased to 70-80%, when the amount of sinter is 12-13kg/t and also end-point [C] is 0.10-0.18%. (65% for raw manganese ore) 4) These effects of high basicity sinter are due to both early slagging and decreasing (%MnO)/[%Mn].
