铁矿石粉循环流化床煤基直接还原的实验研究

Experimental Investigation on Direct Reduction of Iron Ore Powder by Pulverized Coal in a Circulating Fluidized Bed

在小型循环流化床中对铁矿石粉在氮气气氛下用大同煤粉直接还原进行了实验研究,在800～950℃考察了反应温度对铁矿石粉的还原程度及还原产物微观结构的影响.结果表明,随反应温度提高,铁矿石粉还原产物的金属化率及还原度均增加,800～850℃时增幅较大,850～900℃时增幅平缓,900～950℃时又出现较大增幅,950℃时达到63%的金属化率和87%的还原度;与还原前的铁矿石粉相比,还原产物的比表面积和总孔体积在800℃时均增加,而在其他温度时均减小,对应的平均孔径变化规律则相反.

The effect of reaction temperature on the reduction degree and microscopic structure of reduced products,and the reduction process of iron ore powder by Datong pulverized coal in nitrogen was examined in a circulating fluidized bed in the reaction temperature range from 800℃ to 950℃.The metallization and reduction degrees of reduced products increase as the reaction temperature increases.There is a larger increase at 800～850℃,moderate increase at 850～900℃ and the greater increase at 900～950℃.The metallization and reduction degrees can reach 63% and 87%,respectively,when the reaction temperature ascends to 950℃.Compared with the raw iron ore powder,the specific surface area and total pore volume of reduced products are increased at 800℃,while reduced at the other temperatures,the corresponding variation of the average pore size parameters is opposite.