REDUCTION OF TITANIA AND ILMENITE BY METHANE CONTAINING GAS

摘要

Reduction of titania and ilmenite ores by CH_4-H_2-Ar gas mixture was investigated in a laboratory fixed bed reactor. Titania was reduced to titanium oxycarbide in the temperature range of 1200-1500℃. At 1400-1500℃, the extent of reduction of titania to titanium oxycarbide achieved more than 85% in 90 min. Optimum conditions for titanium oxycarbide synthesis by reduction of titania include temperature in the range of 1300-1450℃, methane content 8 vol% and hydrogen content above 35 vol%. Ilmenite ore was reduced by CH_4-H_2-Ar gas mixture to metallic iron and titanium oxycarbide. Metallic iron catalyzed methane cracking and solid carbon deposition. Titanium oxycarbide formed at temperatures as low as 950℃. The optimum temperature for reduction of ilmenite is 1200℃and the optimum methane content is 8 vol%. Increase in hydrogen content increased both rate and extent of reduction. With 5 vol% CH_4-75 vol% H_2-20 vol% Ar gas mixture, the reduction of ilmenite completed in 60 min. Reduction of titanium oxides to oxycarbide with following chlorination may be an efficient alternative technology for processing of titanium minerals.