Experimental Study On Vacuum Carbon Thermal Reduction Of Ilmenite Concentrate

Titanium resources is rich in the west of Panzhihua city. Titanium resources in the region?in TiO₂? accounted for more than 93% of the total national reserves,accounting for 35% of global reserves. Vanadium and titanium ore including ilmenite concentrate and tailings is selected from raw ore. Vanadium ilmenite ore was smelted by the blast furnace and tailings took a second beneficiation, getting titanium concentrate with TiO₂ grade of about 47%. For thermal reduction process with gaseous products, reduction of system pressure and decrease of vapor pressure which generates gaseous substances will facilitate the restoration process. During the evacuation, the reaction gas material is pulled out of the reaction system and gaseous substances generated in the carbon reduction process can effectively be removed by the vacuum carbon thermal reduction method. Based on the above, effect of carbon content and temperature under the condition of vacuum on carbo thermal reduction of Panzhihua titanium was studied in this paper.In order to explore mechanism of carbon reduction to titanium concentrate under the conditions of vacuum, theoretical calculations of solid^phase reduction process of titanium ore by Factsage thermodynamic software was carried out. Effect of temperature, carbon content and pressure on titanium concentrate carbothermal reduction was explored in this paper. The results showed that the reaction condition of12 wt% carbon content, 100 Pa pressure and temperature higher than 1300 ? led to produce the gaseous mixture of Mg, SiO gas and Mn. Additionally, when the pressure,carbon content and temperature was individually 1 Pa, 12 wt% and 1500 ?, the slag grade reached to about 94%.In this experiment, Panzhihua titanium concentrate as raw material, carbon as a reducing agent, impact of reduction temperature, carbon content and holding time onreduction process under vacuum conditions?0.05 Pa? was studied. Weight loss,metallization rate and microstructure was characterized by optical microscopy,SEM^EDS and chemical composition analysis under different experimental conditions. The results showed that reduction temperature, carbon content and increase of holding time had significant effect on weight loss. During temperature of1200 ? ¹400 ?, the slag content of metallic iron increased as the reaction temperature went up. However, metal slag iron content decreased at the temperature of 1400 ? due to iron vapor generation. During 10 wt%¹4 wt% of carbon content,weight loss and metallization ratio of slag iron rose with the increase of carbon content, up to the maximum of 97.15%. With increase of temperature, time and carbon content, metallic iron gradually grew up together and spread to the edges of the sample. Thereby, titanium on the reduction process transformed from Ti₃O₅ to Ti₂O₃ easily. Components of volatiles at elevated temperatures is mainly Fe and Si.