Ironmaking blast furnace is an important reactor in extractive metallurgy. Understanding complex phenomena in the raceway region of an ironmaking blast furnace is important for high efficiency production. A three-dimensional CFD model is described to simulate the flow and thermochemical behaviours in the raceway region of blast furnace. It includes two fuels: pulverized coal and coke bed. The effect of bird's nest of coke bed is examined in terms of gas-particle flows and coal burnouts, where burnouts are investigated at two different locations, namely raceway endpoint and overall surface, respectively. It is found that the existence of bird's nest impacts the length of the jet and extension of the raceway. More importantly, bird's nest does not affect the coal burnouts at raceway endpoint much, but significantly affects the burnout over the raceway surface - lower burnout over the raceway surface when considering bird's nest in the simulations. The model provides an effective tool for understanding and optimizing the operation of a blast furnace. (C) 2014 Elsevier Ltd. All rights reserved.