Carbothermal Reduction of a Primary Ilmenite Concentrate in Different Gas Atmospheres

Abstract

The carbothermal reduction of a primary ilmenite concentrate was studied in hydrogen, argon, and helium. Ilmenite and graphite were uniformly mixed and pressed into pellets. Reduction was studied in isothermal and temperature-programmed reduction experiments in a tube reactor with continuously flowing gas. CO, CO 2 , and CH 4 contents in the off-gas were measured online using infrared sensors. The phase composition of reduced samples was characterized by X-ray diffraction (XRD). Oxygen and carbon contents in reduced samples were determined by LECO analyzers (LECO Corporation, St. Joseph, MI). The main phases in the ilmenite concentrate were ilmenite and pseudorutile. The reaction started with the reduction of pseudorutile to ilmenite and titania, followed by the reduction of ilmenite to metallic iron and titania. Titania was reduced to Ti 3 O 5 and even more to Ti 2 O 3 , which was converted to titanium oxycarbide. Reduction was faster in hydrogen than in helium and argon, which was attributed to involvement of hydrogen in the reduction reactions. The formation of titanium oxycarbide in hydrogen started at 1000°C and was completed in 300 minutes at 1200°C, and 30 minutes at 1500°C. The formation of titanium oxycarbide in argon and helium started at 1200°C and was not completed after 300 minutes at 1300°C.

Carbothermal Reduction and Nitridation of Ilmenite Concentrates

“…12) When titanium suboxides were undetectable in the reduced samples by XRD, it was assumed that the only titanium-containing compound was titanium oxycarbonitride; its composition was calculated using oxygen, nitrogen and carbon concentrations from the LECO analyses. The molar fractions of titanium monoxide TiO, carbide TiC and nitride TiN in the titanium oxycarbonitride are defined with the notation TiOxCyNz.…”

“…Carbothermal reduction of ilmenites of different grades and synthetic rutile in argon, helium and hydrogen was examined by Dewan et al 12,13) Zhang and Ostrovski [14][15][16][17] examined reduction of rutile and ilmenites by methanecontaining gas. In the reduction of ilmenites, iron oxides were reduced to metallic iron and titanium oxides to titanium oxycarbide.…”

Effect of Na₂B₄O₇ Addition on Carbothermic Reduction of Ilmenite Concentrate

“…Bing SONG, 1,2,3) * Xuewei LV, 4) Hubet Huijun MIAO, 1,2) Kexi HAN, 1,2) Kai ZHANG 5) and Run HUANG August 23, 2016) Ilmenite concentrate is a superior quality raw material to production of titania slag. The iron oxide of ilmenite concentrate is reduced to metallic iron and titanium oxide enriched in slag.…”

“…The MFe and FeO contents of the samples were analyzed using wet chemical methods. Under the constant reduction conditions, the metallization degree of iron of ilmenite concentrate sample increased as the Na 2 30) The diffusion rate of the particle increased due to the melting point decreased, and the reaction between solid and solid can be promoted. Figure 5 shows the calculated result of liquidus lines of a typical Panzhihua industrial titania slag with a fixed content of CaO, SiO 2 , MgO and Al 2 O 3 under the constant temperature (1 380°C) by FactSage software.…”

“…Titania slag which was prepared by smelting ilmenite concentrates in an electric arc furnace (EAF) can be served as a superior quality raw materials containing titanium to the subsequent process. [1][2][3] Therefore, titania slag production is essential to improve the comprehensive level of titanium resource utilization. The smelting process of EAF is the current mainstream treatment process.…”