Abstract: To investigate the feasibility of the transport of aluminum block to the slag-steel interface to suppress the oxygen trans-fer from slag to steel in the casting process, a mathematical model for the motion and melting of aluminum block was developed and it was solved in a coupled way. The effects of parameters such as the RH circulation flow rate and the initial size of aluminum block on the motion and melting of aluminum block were investigated based on this model. The results suggest that there are two melting routes for aluminum block. The difference between them lies on the internal melting of aluminum block. According to the results, for the sake of transporting the aluminum block to the slag-steel interface, the circulation flow rate should be larger than 100 t·min^-1 and the origi-nal radius of aluminum block should be at least 10 mm.