Preparation of Fe-Ti(C,N) Composites from Titanomagnetite Concentrate by Carbothermal Reduction in Air Atmosphere

Fe-TiC_1-xN_xcomposites were successfully prepared directly from titanomagnetite concentrate by carbothermal reduction in air atmosphere.The influences of reduction temperature and carbon content on the reaction process and phase evolution during carbothermal reduction of titanomagnetite concentrate were mainly investigated using X-ray diffraction(XRD).The results show that,with the reduction temperature increasing,the phase evolution sequences in the reaction process are as follows:Fe₃O₄→Fe and FeTiO₃→FeTi₂O₅→Ti₄O₇→Ti₂O₃→Ti(C,N).The carbon content is the key factor for gas phase equilibrium in the reaction system.When the carbon content is less than 25%,the partial pressure of CO,CO₂ and N₂ could not reach equilibrium or stays at equilibrium for a short time,and the vanadium titanomagnetite concentrate cannot or partially be reduced to Ti(C,N).At reduction temperature of 1 500℃ for 30 min with 30% carbon content,the TiC_1-xN_xhaving about 3 μm of particle size can be obtained with 0.491 5 of C/N ratio and x=0.67,and the obtained particles are obviously agglomerated.