LAUSR

Steelmaking slag has been used mainly as a material for civil construction. On the other hand, Kubodera et al. proposed a complete utilization process of steelmaking slag in 1979.1,2) The concept is to reduce the steelmaking slag and use it as cement and so on, and to recover iron and phosphorus. It is, in a sense, a no-waste material process, and it seems to be an ideal process. However, to realize this process concept, it is indispensable to charge the hot slag directly into the reduction furnace to decrease the energy consumption and processing cost. This handling is not easy, because charging molten slag into the hot metal bath may cause heavy slag foaming, and slag is easily solidified, if the process takes too much time. Therefore, the target process must be able to control the slag foaming, as well as have high reduction capabilities. So far, some attempts at using molten slag directly in the slag reduction process have been performed in a pilot plant scale. In Germany M. Tschudin et al.3) charged molten stainless-steel slag directly into the oxygen bottom blowing converter and reduced it with carbon addition. The relevant Development of the Molten Slag Reduction Process -2 Optimization of Slag Reduction Process with Molten Slag Charging