Abstract: Polyethylene particles were mixed with limonite powder and bentonite for producing carbon-containing iron ore roasted pellets in order to produce directly reduced iron by direct reduction in a muffle furnace. The effects of reduction temperature, time, molar ratio of carbon to oxygen (C/O) and content of polyethylene on reduction rate of carbon-containing iron ore roasted pellets were studied by orthogonal and single factor experiments. The results showed that the main influential factors include reduction temperature, reduction time, C/O and content of polyethylene. Under the optimum conditions of reduction time of 5 min, temperature of 1350℃, C/O of 1.2 and content of polyethylene of 4%(w), the reduction rate of pellets can reach up to 99.87%. In addition, the reduction time can be shortened, the reduction temperature reduced, and the reduction rate of the pellets improved by adding a certain proportion of polyethylene. Moreover, adding 2%(w) CaF2 in the balling process makes slag and iron separate apparently, and separated slag pulverize naturally. This is conducive to further screening for high-quality directly reduced iron.

Key words: carbon-containing iron ore roasted pellets, direct reduction, limonite, polyethylene, reduction rate

摘要： 以包头地区褐铁矿和无烟煤为主要原料，加入聚乙烯颗粒制成含碳铁矿球团，直接还原制备珠铁. 考察了还原温度、还原时间、配碳量及聚乙烯加入量对含碳铁矿球团直接还原的影响. 结果表明，影响含碳铁矿球团还原率的因素为还原温度、还原时间、配碳量、聚乙烯加入量. 最佳还原条件为C/O摩尔比1.2，加入聚乙烯量4%(w), 1350℃下保温5 min. 该条件下产物还原率最高，达99.87%. 加入一定量聚乙烯可缩短球团还原时间、降低还原温度、提高还原效率. 添加2% CaF2不仅使渣铁分离效果明显，且分离的渣可自然粉化，有利于筛分得到高品质珠铁.

关键词: 含碳铁矿球团, 直接还原, 褐铁矿, 聚乙烯, 还原率