Abstract: Abstract:In the process of copper smelting by fire, it is an ideal method to eliminate the over thick furnace structure of the settling furnace by using iron sulfur alloy with appropriate density and melting point. Regards to previous research, the process of preparing iron-sulfur alloy was optimized. The effects of the binary basicity (R=m(CaO)/m(SiO₂)), the carbon particle size and the carbon addition ratio on the density, and the convergence rate of the iron-sulfur alloy in the process of preparing the iron-sulfur alloy were further explored by means of the metallographic microscope and XRF. The results show that when the basicity is 1.3, the carbon particle size is 0.25~ < 0.42 mm, and the carbon ratio is 1-- the density and aggregation rate of the prepared sulfur iron alloy is the best; under the best preparation condition, the actual utilization rate of sulfur iron is 85.11%, and the loss of iron in slag is much higher than that of sulfur, so the actual sulfur content of the prepared sulfur iron alloy is high.