Simulation Experiment on Direct Reduction of Oxidized Pellets of Vanadium and Titanium-bearing Iron Concentrates by Gas-based Shaft Furnace

Vanadium-bearing titaniferous magnetite resources are abundant in China,but most of them are difficult to be utilized efficiently because of current technical problems with industrial practice,so further efforts should be made to innovate existing technologies.The process of direct reduction by gas-based shaft furnace-smelting and separation by electric furnace provides a new way to efficiently and cleanly utilize the resources.In the experiment,oxidized pellets are prepared from vanadium and titanium-bearing iron concentrates.By simulating direct reduction conditions of gas-based shaft furnace,the effects of reducing gas composition and temperature on pellets’ reduction course,swellability and intensity have been investigated.The results shows that the oxidized pellets prepared from vanadium and titanium-bearing iron concentrates（1% of bentonite is added into it） roasted at 1 250 ℃ for 20 min exhibit excellent properties and possess high compressive strength.Under controlled experimental conditions including composition of reducing gas（pure H₂,H₂/CO=2.5,H₂/CO=1,H₂/CO=0.4 and pure CO） and temperature（850 ℃,900 ℃,950 ℃ and 1 000 ℃）,the resulted pellets boast fast reaction rate and small reduction swellability and can meet the requirements of direct reduction in shaft furnace.Thanks to its advantages in energy saving,environment protection,greater single-machine capacity and high product quality,the process of coal gasification-direct reduction by shaft furnace is expected to be developed aiming at efficient and clean utilization of vanadium-bearing titaniferous magnetite.