Abstract: Boron is an important industrial raw material often sourced from minerals containing different compounds that cocrystallize, which makes it difficult to separate the mineral phases through conventional beneficiation. This study proposed a new treatment called flash reduction–melting separation (FRMS) for boron-bearing iron concentrates. In this method, the concentrates were first flash-reduced at the temperature under which the particles melt, and the slag and the reduced iron phases disengaged at the particle scale. Good reduction and melting effects were achieved above 1550°C. The B₂O₃ content in the separated slag was over 18wt%, and the B content in the iron was less than 0.03wt%. The proposed FRMS method was tested to investigate the effects of factors such as ore particle size and temperature on the reduction and melting steps with and without pre-reducing the raw concentrate. The mineral phase transformation and morphology evolution in the ore particles during FRMS were also comprehensively analyzed.