含钒钛铁精矿氧化球团气基竖炉直接还原模拟试验

我国钒钛磁铁矿资源丰富,但综合利用难度大,现有工艺仍存在一些问题,工艺流程还有待完善和革新。气基竖炉直接还原-电炉熔分新工艺为钒钛磁铁矿资源清洁高效综合利用提供了新途径。以含钒钛的铁精矿为原料制备氧化球团,模拟气基竖炉直接还原条件,研究了还原气组分和温度对球团的还原进程、还原膨胀以及还原强度的影响。结果表明:以钒钛铁精矿为原料,配加1%膨润土,在1 250℃下焙烧20 min后,所制备氧化球团性能良好,具有较高的抗压强度。在恒定还原气组分(纯H2、H2/CO=2.5、H2/CO=1、H2/CO=0.4和纯CO)和温度(850、900、950和1 000℃)下,钒钛铁精矿球团还原速率快、还原膨胀率小(<20%),可满足气基竖炉直接还原工艺要求。煤制气-气基竖炉直接还原凭借其能耗小、环境友好、单机产能大、产品质量好等优点,将在钒钛磁铁矿资源高效清洁综合利用领域得到发展。

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.