1990 Volume 76 Issue 11 Pages 1831-1838
The smelting reduction process of Mn ore both in a dephosphorization and a decarburization converter has been examined in order to increase [Mn] at blow end of BOF. The new hot metal dephosphorization process in a top and bottom blowing converter (SRP : Simple Refining Process), in which BOF slag is used as a dephosphorization agent, is applied for the present study.
The following results are obtained with the experiments in a 2 kg crucible and a 2 t laboratory scale converter :
1. 1.5%[Mn] at blow end of BOF can be achieved without [S] increase by the following features of the present process :
(1) Simultaneous treatment of Mn ore reduction, dephosphorization and desulphurization of hot metal in a dephosphorization converter. (Coke is charged and combusted in some minutes to supply energy for the reduction of Mn ore.)
(2) MnO-rich slag from a decarburization converter is used as a dephosphorization agent in a dephosphorization converter.
(3) Less slag operation in a decarburization converter with large amount of Mn ore charge.
2. The yield of Mn is increased by about 10% by the recycle of BOF slag ; such high yield of Mn as 63% can be achieved in the present process.
