Reduction of Panzhihua titanium-bearing oxidized pellets by CO-N2-H2 gas

The effect of H 2 gas content on the reduction of Panzhihua titanomagnetite concentrate pellets by carbon monoxide was investigated by isothermal reduction experiment using CO-N 2 -H 2 gas mixtures in a vertical electric resistance furnace. The morphology and phase transformation of reduced samples obtained were detected by scanning electron microscopy, energy disperse spectroscopy analysis and X-ray diffractometry respectively. The results show that increasing H 2 content will enhance the initial stage of reduction rate apparently. There are two reasons responsible for this effect, one is that H 2 accelerates the chemical reaction, and the other is that the addition of H 2 gas can improve the porosity of pellet intensively. It is noteworthy that this effect is more obvious when the reduction temperature reaches 1473 K with sticking phenomenon happening. There are no crystalline phases which can be found such as ulvospinle, ilmenite, ferrous-pseudobrookite and any titanium oxide except titanomagnetite (TTM). The reduction progress is suggested as follows: 1) Fe 2 O 3 →Fe 3 O 4 →FeO→Fe; 2) Fe 2 TiO 5 →Fe 2 TiO 4 +Fe 3 O 4 →TTM. Element Al migrates and gets enriched in high titanium content iron ores, and eventually Al to Ti molar ratio is 1:3. Al is likely to dissolve in titanium iron oxides to form a kind of composite iron compound, which results in the restrain of reduction.