Hot metal yield optimization of a blast furnace based on constructal theory

Constructal theory is introduced into the hot metal yield maximization of the blast furnace in this paper. Generalized constructal optimization of a blast furnace is performed for a specified total raw material cost. The optimal distribution of each raw material cost in the total cost, namely “generalized optimal construct”, is obtained. Besides, the optimal charge composition of the blast furnace is also obtained. The effects of blast parameters, agglomerate ratio and pulverized coal dosage on the optimization results are analyzed. The results show that the hot metal yield after generalized constructal optimization is 1027.4 kg, and is improved by 2.64% compared with that before optimization. For actual production of the blast furnace, when the total cost is fixed, decreasing the blast oxygen enrichment, blast volume, and agglomerate and increasing pulverized coal dosage can increase the hot metal yield. Increasing blast humidity can increase the hot metal yield when the blast humidity is always under a certain value. The contribution of this paper is to optimize the hot metal yield of the blast furnace based on new methodology, which leads to a good economic performance of the blast furnace iron-making process and provides new guidelines for the design of this process.