Abstract: This paper studies the carbon reduction and magnetic separation of copper slag's flotation tailings. The impact of the roasting temperature and alkalinity on the reduction and effect of different size of reduzate on magnetic separation are investigated. The results show that Fe₃O₄ and fayalite are the main forms of iron among the copper slag after iron ore phase analysis. With the roasting temperature of 1 175 ℃，the carbon content of C/O=1.2, the alkalinity of R=0.4 and the size of less 42 um, the magnetic materials of TFe%=74.7% are collected after reduction and magnetic separation. The iron particles are dispersed in the reduzate and the copper are embedded in the iron in the form of matte.