The flash ironmaking process is an innovative high-intensity process that uses iron ore concentrates directly without further treatment. Process intensity is related to the production rate per unit volume of reactor. The fineness of the concentrate particles allows a very rapid reaction rate, thus requiring reaction time measured in seconds instead of the minutes and hours it takes to reduce pellets and even iron ore fines. This novel process also makes it unnecessary to use coke that is required in the currently dominant ironmaking process using the blast furnace. Cokemaking is one of the most problematic process steps in the current steel industry and its elimination would greatly benefit the industry.
Mohassab and Sohn at the University of Utah are leading a team to explore the chemistry of slag under the conditions of the flash ironmaking process. The slag chemistry, together with the nature of the gas it is in contact with, determines the extent of removing impurities from iron into slag. Sulfur, together with phosphorus, is the most harmful impurity in steel and thus must be eliminated to the lowest possible level. Mohassab and Sohn studied, for the first time, the effect of water vapor on the distribution of sulfur between slag and molten iron in the temperature range 1550-1600°C under CO/CO2/H2/H2O mixtures with pO2 = 10-10~10-9 atm. These are the conditions encountered in the novel flash ironmaking process that is being developed with the combined support of U.S. Department of Energy, American Iron and Steel Institute, and the University of Utah. Water in the gas atmosphere was found to increase the sulfur absorption by the slag.