Experimental Research On Direct Reduction Of Iron Oxide

In recent years, with the rapid development of iron and steel industry, mineral resour- ce of high grade ore are declining and exhausted. Therefore, it is of significance to intensi- fy utilization of domestic complex iron ore resources. Vanadiferous titanomagnetite ore is quite rich in China, which contain Vanadium, Titanium, Iron have quite high value of com- prehensive utilization. However, the mineral belongs to complex ore,whose component is very complex, content is low grade, and it is hard to utilizing vanadiferous titanomagnetite ore. Therefore, it is very significant to develop new technology on utilizing vanadiferous titanomagnetite ore.In this paper, iron oxides was taken as main research objects. Reduction behavior of iron oxides and fundamentals of strengthening reduction processes were deeply discussed synthetically by these theories of kinetics, thermodynamics,analytical chemistry and so on, and modern microscopic measuring and testing technology,such as optical microscope, X- ray diffraction, and scanning electron microscope and so on. The following conclusions were obtained:1.Based on the carbon reductive behavior of Fe₂O₃ show that with the rising of reduc- tive temperature, reductive time and carbolic ratio, the content of iron is increasing. The content of iron is up to 94.89% under the conditions of reductive temperature 1150℃, reductive time 1 hour and carbolic ratio 1.9.2.Based on the gas reductive behavior of Fe₂O₃ show that the content of iron is up to 96.63% under the conditions of reductive temperature 1150℃, reductive time 6 hour and amount of CO gas flow 35 mL/min.3.Based on the carbon reductive behavior of Fe₃O₄ show that with the rising of reduct- ive temperature, reductive time and carbolic ratio, the content of iron is increasing. The content of iron is up to 98.16% under the conditions of reductive temperature 1150℃, reductive time 0.75 hour and carbolic ratio 1.9.4.In this research, alkali metal additives were used to reinforce Fe₂O₃ reduction. The results indicated that K₂CO₃ could accelerate the reduction of Fe₂O₃. The content of iron is up to 82.71% under the conditions of reductive temperature 950℃, reductive time 1 hour, carbolic ratio 1.9 and 3% K₂CO₃.5.In this research, alkali metal additives were used to reinforce Fe₃O₄ reduction. The results indicated that K₂CO₃ could accelerate the reduction of Fe₃O₄. The content of iron is up to 78.24% under the conditions of reductive temperature 950℃, reductive time 0.75 hour, carbolic ratio 1.9 and 2% K₂CO₃.6.According to the researches of alkali metal additives were used to reinforce Fe₂O₃ reduction by optical microscope, X-ray diffraction,and scanning electron microscope, it could be indicated that K₂CO₃ can speed up reductive reation rate of Fe₂O₃. K+ is enwrapp- ed by iron and afford the crystal nucleus for iron, which caused that the reductive reation is easier to proceed and iron grains are easier to grow into serial iron crystals and make the separation of rductive products get better.