Phase Evolution Mechanism And Purification Of Titanium Oxycarbide (TiC_xO_y) Produced By Carbothermic Reduction Of Ilmenite

Titanium and its alloys have excellent physical and chemical properties due to important lightweight structural and new functional materials,known as"future metals"and"third metals."Although titanium has abundant reserves in the earth's crust,the current smelting process is cumbersome,energy-intensive,and costly,which makes titanium metal expensive,which in turn limits its wider application.The paper takes the titanium concentrate of a titanium company in Guangxi as the research object,based on the preparing conductive performance good anode titanium oxycarbide?TiC_xO_y?and electrolytic titanium oxycarbide?TiC_xO_y?to obtain the relevant technology of titanium,titanium iron ore carbon thermal reduction mechanism for making carbon titanium oxide phase evolution and purification research,providing the high quality for electrowinning of titanium metal front materials,promoting the value of ilmenite,to reduce cost and improve enterprise producing titanium,provide basic parameters based on the competitiveness of the enterprises.Carbothermal reduction investigates the effects of carbon ratio,reduction temperature,and reduction time on the production of titanium oxycarbide,and uses phase analysis?XRD?and X-ray photoelectron spectroscopy?XPS?to characterize the phase characteristics of the reduced product.To clarify the phase composition,combined with thermodynamic analysis of the mechanism of direct reduction of ilmenite and the phase change law,reveal the phase characteristics of titanium oxycarbide?TiC_xO_y?and its reaction history and mechanism.A large number of samples were prepared based on the optimal conditions for the carbothermal reduction of titanium concentrate,and the experiments of kerosene flotation decarburization,magnetic separation and iron removal were carried out to obtain the best conditions for purifying TiC_xO_yand obtaining higher purity TiC_xO_yproducts.The carbothermal reduction results show that the higher temperature and the more sufficient the carbon content,the faster carbothermal reduction of ilmenite to titanium oxycarbide.When the carbon content is 22.92%-29.95%and the temperature is 1550?,the reduction holding time is 10min,it can be completely reduced to get TiC_xO_yand Fe.Combining the XPS test results of Ti and the phase XRD results to determine the carbothermal reduction products Ti O,TiC,TiC_xO_yto avoid misjudgment by a single XRD method.The phase results and thermodynamic analysis show that the solid carbon reduced ilmenite?Fe Ti O3?The reaction generates a certain amount of CO.Although argon gas flows between the electric furnace and the outside world,part of the CO gas that was not taken away in time by the argon gas also participated in the partial reduction reaction,but CO cannot reduce Ti O and Ti₂O₃to titanium oxycarbide at 1550?.,and the resulting titanium oxycarbide is mainly solid carbon,which plays a role in reduction.At 1550?,the ilmenite?Fe Ti O₃?carbothermal reduction process gradually changes in the following order:Fe Ti O₃?Fe Ti₂O₅?Ti₂O₃+Fe?Ti O+Fe?TiC_xO_y+Fe?TiC+Fe;When the temperature at1400?,there is no Ti O,and the product sequence is:Fe Ti O₃?Fe Ti₂O₅?Ti₂O₃+Fe?TiC_xO_y+Fe?TiC+Fe.Purification test results show that after the grinding particle size reaching-400 mesh,flotation can remove elemental carbon,magnetic separation to separate most of the titanium oxide,and some TiC_xO_yand Fe are not completely dissociated.Iron powder dissolves iron in a high-temperature iron bath to separate TiC_xO_y.1.5 g TiC_xO_yconcentrate is acid-dissolved for impurity removal.At 25?,using 5 m L of nitric acid with a concentration of 1 mol/L,the reaction time reaching 2 h,the acid solution treatment effect is the best,the total impurities and the main impurity elements Ca and Fe content can be reduced to 5.63%,0.68%and 1.4%,respectively.