Blast furnace (BF) is an efficient but complex chemical reactor for converting iron ore to liquid iron. In BF practice, after the planned blast-off operations, air may be re-blown in gradually, usually integrated with pulverised coal injection (PCI) operation so as for resuming stable raceway and production, but the in-furnace phenomena in re-blowin process are not clear yet. A three-dimensional (3D) computational fluid dynamics (CFD) model is developed and used to describe the re-blowin process in an industrial-scale BF. The model offline integrates a raceway model and a PCI model. The models are validated against the experimental measurements. The in-furnace phenomena of four key steady states in the normal re-blowin operation are illustrated using the industrial-scale model, in terms of the flow field, temperature field, distribution and concentration of gas species within the raceway and the surrounding coke bed. The simulation results indicate a larger blast volume can enlarge the size of the recirculation region of the raceway and can help recover the raceway operation quickly. On the other hand, starting PCI operation with O-2 enrichment are tested, and indicate insignificant enhancement on the re-blowin process. This model provides a cost-effective way to understand the re-blowin operation for operation design and optimisation. (C) 2019 Elsevier B.V. All rights reserved.