Study on Melting Carburization Behavior of Flash Ironmaking

The final carbon content of the molten iron is saturated during the traditional blast furnace smelting process.However,the reaction in the flash furnace occurs at the stage of material floating and the carburizing effect of the solid charge and the molten iron in the blast furnace cannot occur without the compression of the solid material column,thus the final carbon content of molten iron is unknown.In order to obtain the final carbon content during flash inromaking,carburizing reaction at the bottom of the molten pool in flash ironmaking was studied.Firstly,the theoretical study of the iron-carbon phase diagram was investigated.The effect of reaction time,coke particle size,coke bed height and weight loss rate of the raw materials on the final carbon content of molten iron were investigated based on this theoretical analysis.The optimum conditions were as follows:carburization time was 240 min,coke particle size was 5~8 mm,coke addition amount was 70 g.The material weight loss rate was 26% and the maximum carbon content was 4.73% under the optimum conditions.In order to further explore the changes of elements in iron-carbon alloy during carburizing,the SEM-EDS characterization of carburized iron with a carbon content of 4.73% was detected,indicating that the rod-like graphite carbon is irregularly embedded in the iron-carbon alloy in a condensed state,and two different contrasts(FeC phase and Fe₃C phase) were presented at the edge of the graphite carbon.