对盖碳保护下敞焰加热含碳球团堆积料层的直接还原方法（ＣＯＦ法）进行了研究。试验结果表明，在完全燃烧的强氧化气氛中，仅用１０～１５ｍｍ的碳粒层就可有效地防止或明显减缓炉气对炉料的氧化，使海绵铁的金属化率在较宽的工艺参数范围内稳定地达到９０％以上，甚至超过９５％。盖碳保护后，料层一般可达４～７层球厚，使单位炉底面积生产率可达６０ｋｇ／（ｍ２·ｈ），并且在炉型结构、燃烧方法、炉膛气氛和操作参数的选择方面都有较大的灵活性。 The direct reduction method (COF method) of carbon fiber pellet accumulation by open flame heating under capped carbon was studied. The test results show that in a fully oxidized atmosphere, the use of only 10 ~ 15mm carbon layer can effectively prevent or significantly reduce furnace gas oxidation of the charge, the sponge iron metallization rate in a wide range of process parameters Within the range of more than 90%, even more than 95%. Cover carbon protection, the material layer generally up to 4 to 7 ball thickness, so that the unit floor area productivity up to 60kg / (m2 · h), and in the furnace structure, combustion method, the furnace atmosphere and the choice of operating parameters Have greater flexibility.