Sulfur and phosphorus distribution between liquid iron and magnesia-saturated slag in molecular hydrogen/water atmosphere relevant to a novel green ironmaking technology

As an integral part of a research project which aimed to develop a novel green ironmaking process, an experimental determination of the sulfur and phosphorus distribution ratios, LS and LP, respectively, between molten iron and CaO-MgO(Saturated)-SiO2-Al 3O3-FeO slag was determined in the temperature range 1550-1650°C. Oxygen partial pressure was controlled by H2/H2O equilibrium in the range of 10-10-10-8 atm. For sulfur distribution, it was found that the trend of the distribution is the same as the previous work done under CO/CO2 atmosphere but LS in this case is 38-44 times less under similar oxygen partial pressure. This might be attributed to the impact of H2 on the distribution. Considering the fact that the input sulfur in the proposed process is approximately 34 times less than the blast furnace process, the proposed process would produce hot metal with approximately the same sulfur content to the hot metal produced by the blast furnace. For phosphorus distribution, LP was 450-1050 times that of the blast furnace. Also considering the amount of phosphorus input in the two processes, it was found that the expected P content in iron in the new process would be approximately three times less than in the blast furnace hot metal. This means that the proposed process will produce hot metal with much lower phosphorus which will minimize the need for dephosphorization in the steelmaking stage.