DISSOLUTION AND REDUCTION BEHAVIOR OF MANGANESE ORE IN LESS SLAG BLOWING AT BOF

In order to improve the yield of Mn in less slag blowing at BOF, the dissolution and reduction behavior of manganese ore have been studied in 100kg scale test. The results obtained in this work are as follows. 1) Dissolution of manganese ore into BOF slag is quite easy at 1600-degrees-C, but it is not so easy at 1400-degrees-C because of the precipitation of solid MnO-FeO. So, it is hard to dissolve manganese ore in the first harf of blowing at low temperature. 2) If the amount of manganese ore addition is small, manganese ore has remarkable effect on slagging of BOF slag. But, if its amount is more than that of BOF slag, the melting point of BOF slag becomes higher than 1450-degrees-C. 3) Reduction rate of manganese ore mainly depends on bath temperature, and higher temperature is desirable. On the other hand, the reduction rate is not affected by carbon content of steel in the range of [C] greater-than-or-equal-to 1%. 4) From these results, in order to improve the yield of Mn, early slagging and keeping bath temperature as high as possible are very important.