Charge of hot coke and iron-bearing materials into an ironmaking blast furnace (BF) may bring significant energy and environmental benefits to the BF process. However, there is little information about the quantitative effects of hot charge operation on BF flow and performance. This paper presents a numerical study of multiphase flow, heat and mass transfer in a BF by a process model. The applicability of the model in predicting BF performance is first confirmed by different applications. It is then used to study the effects of hot charge operation at different temperatures. The results are analyzed in detail with respect to BF flow and performance. It is shown that compared to the conventional operation, hot charge operation can lead to an increased productivity, decreased coke rate and CO2 emission, and at the same time, increased gas pressure and top gas temperature. These effects vary with hot charge temperature. (C) 2013 Elsevier Ltd. All rights reserved.