Study on the Effect of P ₂ O ₅ Content in Steel Slag on Dephosphorization by Carbothermal Reduction

Steel slag is one of the primary solid wastes in the metallurgical industry. In this study, thermodynamic simulation and laboratory thermal state experiments are combined to treat phosphorus‐containing steel slag by the carbothermal reduction process. It analyzes the composition, physical phase, and structure of both the original and reduced slag, elucidates the migration patterns of phosphorus within the slag, and investigates the influence of P 2 O 5 content of converter steel slag on the carbothermal reduction reaction. The results show that the dephosphorization rate escalates with the increase of P 2 O 5 content in the original slag under the experimental conditions of 1773 K, the carbon equivalent of 1.5 times, and the reaction time of 30 min, achieving the maximum dephosphorization rate of 85.27% when the mass fraction of P 2 O 5 in the original slag is 6.48%. The high P 2 O 5 content of steel slag can significantly enhance phosphorus removal by the carbothermal reduction reaction. The processed slag can be returned to the converter, thereby decreasing slag production and enabling the utilization of substantial quantities of stock slag, resulting in energy conservation and emission reduction within the steel and iron industry.