Solid state steelmaking: process technical and economic viability

Two published papers on a novel solid state steelmaking (S-3) process have been reviewed, with particular regard for the technical and economic feasibility of the process. The S-3 process involves a two stage twin role casting to solid state decarburisation route and it is claimed to improve product quality and reduce process complexity, by eliminating oxygen blowing in the BOF. The process kinetics of the solid state decarburisation stage has led research to be directed towards a process with an initial starting carbon concentration of 1.2%. This relatively low start carbon level restricts exploitation of the S-3 process to scrap intensive routes, such as an EAF, or alternative ironmaking feed, such as HIsarna. Consequently, it is believed that uptake of this process will be limited. Should the mass transfer limitations inherent in the solid state decarburisation be overcome then the possibility to deploy the S-3 process to sites fed by the traditional blast furnace would be transformational for the steel industry, reducing capital and operating cost and having a major impact on CO2 and energy requirements.