Abstract: In consideration of the devolatilization of lump coal in the upper zone ot the melter gasmer anti the burning of tar and hydrocarbon in volatile matter with oxygen, an operating line diagram of the melter gasifier was established by utilization of the improved Rist operating line principle. The Rist operating line diagram can directly reflect the effect of various factors on the energy consumption of the ironmaking process. Changes of the Rist operating line were discussed after the burning of volatile matter and hydrocarbon with blowing oxygen in the upper zone of the melter gasifier. The oxygen consumption and energy consumption were compared when charging different lump coals and semi coke. The changes in gas oxidation degree, temperature and volume change as well as their influence on the energy consumption were analyzed when charging semi coke after volatile matter removal.