Abstract
Direct iron smelting-reduction processes have been developed as an alternative to the blast furnace process for making molten, slag-free iron. The main incentive behind their development was to produce smaller quantities of hot metal from iron oxide feed stocks, preferably low-grade ore and/or without pelletization, utilizing noncoking coal as a reducing–carburizing agent. Although the blast furnace process will not be replaced in the near future, with these smelting-reduction processes due to their large-scale thermal and chemical efficiency, the smelting-reduction processes are serious contenders for small-sized local regional markets for hot metal production, which can be used in electric arc furnace steelmaking in mini-mills and future applications. Thus, the objective of this article is to lay out the operational properties of the commercial and nearly commercialized smelting-reduction processes.