关键词: 磁铁精矿, 含碳球团, 直接还原, 碳酸钠, SEM-EDS能谱分析

Abstract: In order to explore the new technology of direct reduction iron and improve product quality,carbon was added in a low sulfur magnetite concentrate with the total iron contents of 64.71% for the preparation of raw pellets and dextrin as organic binder.Then,the reduction roasting tests were carried out under the protection of nitrogen.The results showed that under the conditions of coke dosage of 20%,reduction temperature of 1 150 ℃,reduction time of 1 h,dextrin addition of 1%,grinding fineness of -0.074 mm accounting for 80% and magnetic field intensity of 80 kA/m,direct reduced iron product with total iron contents of 92.67% and iron recovery rate of 95.74% was obtained.With the addition of 1.6% sodium carbonate,the total iron contents of the direct reduced iron product reached 93.55%,which increased by nearly one percentage point,and the iron recovery rate decreased to 94.20%.SEM-EDS analysis showed that the product has large grain size and obvious metal iron diffraction peak,which can be used as high quality raw material to replace scrap steel in electric furnace steelmaking.

Key words: magnetite concentrate, carbon-containing pellets, direct reduction, sodium carbonate, SEM-EDS energy spectrum analysis