Abstract: To study the scheduling problem in the captive oxygen plant of a large-scale integrated steel mill, a mixed integer linear program (MILP) model was developed to minimize the oxygen emission. On the basic of the model, the oxygen production scheduling during blast furnace (BF) blow-down was studied as a case, and the effect of initial pipe network pressure (at the beginning of the BF blow down) on the oxygen emission ratio was analyzed. The system presents the oxygen emission when the initial pipe network pressure is larger than a critical value. The oxygen emission ratio increases with the increase of initial pressure in an approximately linear relationship, and the larger the buffer capacity of the high-pressure pipe network, the bigger the slope of this linear relationship. When there is the oxygen emission and for the same initial pressure of high-pressure pipe network, the bigger the buffer capacity of high-pressure pipe network, the smaller the oxygen emission ratio. This relationship tends to become inconspicuous as the initial pressure increasing, when the initial pressure is equal to the maximum allowed pressure, the oxygen emission ratio is unaffected by the buffer capacity of the high-pressure pipe network.