Abstract
Recent topics and tendency of direct ironmaking (direct reduction) processes using non-coking coal as reductant are surveyed.
The significance of direct reduction is mentioned in comparison with the conventional ironmaking process using bast furnaces. Althongh more than 98% of iron in the world is produced by blast furnaces, iron and steel industries have been strongly interested in the development of direct reduction processes due to the worries of energy supply in the future.
In some direct reduction processes, non-coking coal is charged to reduction furnace without any chemical reforming. Rotary kiln is mainly used in these processes. Five commercial plants of the SL/RN process are operating in the world. Features of reductant-included-pellets are also described.
Finally, different direct reduction processes are presented. In the processes, reduncing gas in advance reformed from non-coking coal is injected to reduction furnace.The Midrex process is mentioned as a typical example.
