Experimental study on the preparation of ferrophosphorus alloy using dephosphorization furnace slag by carbothermic reduction

Abstract With the development of the duplex converter process, the amount of dephosphorization furnace slag is increasing, and it has relatively low basicity. It has been indicated that the recovery of valuable elements from dephosphorization slag by carbothermic reduction has great environmental and economic benefits due to its high content of P, Fe, and Mn. In this work, the experimental slag was reduced by carbon powder in a resistance furnace at 1,550°C. The results show that 76.82% of P, 99.60% of Fe, and 11.82% of Mn in the slag are recycled at basicity 1.0, and the recovery ratios of P, Fe, and Mn are 34.58, 78.89, and 13.85% at basicity 2.0, respectively. The ferrophosphorus obtained from the reduction of the dephosphorization furnace slag can be used as a raw material for steel-making alloy, and the residual steel slag can be used as cement and other building materials. This work provides a reference for recycling and resource utilization of dephosphorization furnace slag.