Effects of Mineral Oxides on the Precipitation Micro-Morphology of Metallic Iron in the Reduction of Iron Oxides under CO Atmosphere

摘要

Grain sticking often occurs in the gaseous fluidized ironmaking of fine ore,which is closely related to the precipitation morphology of metallic iron on the surface of ore particles.In this work,simulating the gas-solid reduction process of iron ore,in situ observations was used to investigate effects of mineral oxides on the precipitation morphology evolution of metallic iron in the reduction of iron oxides with CO.Results indicate that the precipitation morphology of metallic iron is related to the quantity of doping mineral oxides.The minimum mole fraction of doping oxide (NAyox)which can inhibit the growth of iron whiskers is related to its cation radius (rAx+),its extranuclear electronic layers (nAx+)and valence electrons (qAx+),which can be expressed as:NAyox =1.3 ×10-5 ·r2Ax+ ·(√)nX+/(qAx+-1) !.