Study On Reduction Kinetics Of FeO In Smelting Slag

FeO-containing slag is very common in the process of iron and steelmaking process. In the traditional blast furnace ironmaking and smelting reduction ironmaking processes, the reduction mechanism and speed of FeO slag by solid carbon or gas reductant largely determine the total efficiency of the process. Therefore, based on the previous research, this paper is a further study on the reduction mechanism of FeO in smelting slag by graphite crucible. The temperature is1410-1500℃, while the alkalinity is0.94-1.37. The slag system in this study is CaO-SiO2-MgO-Al2O3-FeO. The purpose of this study is to find out the reduction kinetics mechanism and get more first-hand information for the improvements in blast furnace iron making process and other metallurgical processes. The slag system used in this study is blast furnace slag with the addition of FeO, while the graphite crucible is reducing agent. The influence factors include temperature, basicity, and the initial content of FeO. The conclusions are performed as follows:1Reduction of FeO in CaO-SiO2-MgO-Al2O3-FeO system by graphite carbon is an apparent second-order reaction. The apparent activation energy is342.37kJ/mol. The Boudouard reaction activation energy is152.98kJ/mol while the mass transfer of FeO in slag is355kJ/mol.2Reduction rate controlled both by the mass transfer of FeO in slag and the interfacial chemical reaction (direct reduction and carbon gasification), while the former ranks the foremost.3. This study gives the total reaction rate of each experiment, which is close to the mass transfer rate of FeO in slag. When alkalinity is1.22, temperature is1410-1550℃, the empirical rate equation of the reaction is:4. The apparent rate constants increased with the increasing of temperature, alkalinity, and the initial content of FeO in slag. The temperature influence the reaction rate most, then the initial content of FeO in slag and the basicity.