Abstract: In order to ensure the recycling effect of converter slag after gasification dephosphorization,the thermal experiment of gasification dephosphorization slag as feedstock for slag dephosphorization was carried out in the laboratory.The results showed that the gasification dephosphorization slag had the characteristics of high calcium oxide,high basicity,low P₂O₅ and high FeO.It could be directly used for secondary dephosphorization without going through the slagging process.When the dephosphorization of molten iron was carried out by gasification dephosphorization slag,the end point [P] content of molten iron increased with the increase of experimental temperature.The phosphorus mass fraction of the end point molten iron at 1 500 ℃ was only 0.067 %,and the corresponding dephosphorization rate was 40 %.Comparing the dephosphorization speed of the gasification dephosphorization slag and the preparation dephosphorization agent,it could be known that in the prereaction stage,the slag-forming rate of the gasification dephosphorization slag was fast,and the molten iron [P] content of the gasification dephosphorization slag was lower than that of the preparation dephosphorization agent.However,due to the phosphorus capacity,the end dephosphorization effect of the gasification dephosphorization slag was not as good as that of the dephosphorization agent.Therefore,it was recommended that the gasification dephosphorization slag can be used in combination with the newly formed slag agent in the industrial test to reduce the slag production while ensuring the dephosphorization effect.

Key words: converter slag, gasification dephosphorization, recycle utilization, secondary dephosphorization